| 1. |
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| 2. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 3. |
- Kristanl, Matej, et al.
(författare)
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The Seventh Visual Object Tracking VOT2019 Challenge Results
- 2019
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Ingår i: 2019 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW). - : IEEE COMPUTER SOC. - 9781728150239 ; , s. 2206-2241
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Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2019 is the seventh annual tracker benchmarking activity organized by the VOT initiative. Results of 81 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in the recent years. The evaluation included the standard VOT and other popular methodologies for short-term tracking analysis as well as the standard VOT methodology for long-term tracking analysis. The VOT2019 challenge was composed of five challenges focusing on different tracking domains: (i) VOT-ST2019 challenge focused on short-term tracking in RGB, (ii) VOT-RT2019 challenge focused on "real-time" short-term tracking in RGB, (iii) VOT-LT2019 focused on long-term tracking namely coping with target disappearance and reappearance. Two new challenges have been introduced: (iv) VOT-RGBT2019 challenge focused on short-term tracking in RGB and thermal imagery and (v) VOT-RGBD2019 challenge focused on long-term tracking in RGB and depth imagery. The VOT-ST2019, VOT-RT2019 and VOT-LT2019 datasets were refreshed while new datasets were introduced for VOT-RGBT2019 and VOT-RGBD2019. The VOT toolkit has been updated to support both standard short-term, long-term tracking and tracking with multi-channel imagery. Performance of the tested trackers typically by far exceeds standard baselines. The source code for most of the trackers is publicly available from the VOT page. The dataset, the evaluation kit and the results are publicly available at the challenge website(1).
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| 4. |
- Kanoni, Stavroula, et al.
(författare)
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Implicating genes, pleiotropy, and sexual dimorphism at blood lipid loci through multi-ancestry meta-analysis.
- 2022
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Ingår i: Genome biology. - : Springer Science and Business Media LLC. - 1474-760X .- 1465-6906 .- 1474-7596. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- Genetic variants within nearly 1000 loci are known to contribute to modulation of blood lipid levels. However, the biological pathways underlying these associations are frequently unknown, limiting understanding of these findings and hindering downstream translational efforts such as drug target discovery.To expand our understanding of the underlying biological pathways and mechanisms controlling blood lipid levels, we leverage a large multi-ancestry meta-analysis (N=1,654,960) of blood lipids to prioritize putative causal genes for 2286 lipid associations using six gene prediction approaches. Using phenome-wide association (PheWAS) scans, we identify relationships of genetically predicted lipid levels to other diseases and conditions. We confirm known pleiotropic associations with cardiovascular phenotypes and determine novel associations, notably with cholelithiasis risk. We perform sex-stratified GWAS meta-analysis of lipid levels and show that 3-5% of autosomal lipid-associated loci demonstrate sex-biased effects. Finally, we report 21 novel lipid loci identified on the X chromosome. Many of the sex-biased autosomal and X chromosome lipid loci show pleiotropic associations with sex hormones, emphasizing the role of hormone regulation in lipid metabolism.Taken together, our findings provide insights into the biological mechanisms through which associated variants lead to altered lipid levels and potentially cardiovascular disease risk.
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| 5. |
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| 6. |
- Chen, Jingjing, et al.
(författare)
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FishBuddy : Promoting Student Engagement in Self-Paced Learning through Wearable Sensing
- 2017
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Ingår i: 2017 IEEE INTERNATIONAL CONFERENCE ON SMART COMPUTING (SMARTCOMP). - : IEEE. - 9781509065172 ; , s. 211-219
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Konferensbidrag (refereegranskat)abstract
- Student engagement is crucial for successful self-paced learning. Feeling isolated during self-paced learning with neither adequate supervision nor intervention by teachers may cause negative emotions such as anxiety. Such emotions may in turn significantly weaken students' motivation to engage in learning activities. In this paper, we develop a self-paced learning environment (FishBuddy) that aims to reduce anxiety and promote student engagement. We construct and implement a physiologically-state-aware performance-evaluation model for identifying potentially fruitful moments of intervention when students show frustration during learning activities using an Apple Watch application that measures heart rate and alerts the student to watch a visualization of his or her own physiological state. We have conducted an experiment with 20 first-year undergraduate students, randomly separated into an experimental group and a control group, who carry out online, self-paced English grammar exercises. The students in the experimental group used FishBuddy and those in the control group did not. The self-reports from both groups show that FishBuddy significantly reduced reported experiences of anxiety and isolation in the experiment. Further to this, students who used FishBuddy were engaged longer with the exercises. The average scores on the exercises between the two groups, however, were not significantly different.
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| 7. |
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| 8. |
- de las Fuentes, Lisa, et al.
(författare)
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Gene-educational attainment interactions in a multi-ancestry genome-wide meta-analysis identify novel blood pressure loci
- 2021
-
Ingår i: Molecular Psychiatry. - : Springer Nature. - 1359-4184 .- 1476-5578. ; 26:6, s. 2111-2125
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Tidskriftsartikel (refereegranskat)abstract
- Educational attainment is widely used as a surrogate for socioeconomic status (SES). Low SES is a risk factor for hypertension and high blood pressure (BP). To identify novel BP loci, we performed multi-ancestry meta-analyses accounting for gene-educational attainment interactions using two variables, “Some College” (yes/no) and “Graduated College” (yes/no). Interactions were evaluated using both a 1 degree of freedom (DF) interaction term and a 2DF joint test of genetic and interaction effects. Analyses were performed for systolic BP, diastolic BP, mean arterial pressure, and pulse pressure. We pursued genome-wide interrogation in Stage 1 studies (N = 117 438) and follow-up on promising variants in Stage 2 studies (N = 293 787) in five ancestry groups. Through combined meta-analyses of Stages 1 and 2, we identified 84 known and 18 novel BP loci at genome-wide significance level (P < 5 × 10-8). Two novel loci were identified based on the 1DF test of interaction with educational attainment, while the remaining 16 loci were identified through the 2DF joint test of genetic and interaction effects. Ten novel loci were identified in individuals of African ancestry. Several novel loci show strong biological plausibility since they involve physiologic systems implicated in BP regulation. They include genes involved in the central nervous system-adrenal signaling axis (ZDHHC17, CADPS, PIK3C2G), vascular structure and function (GNB3, CDON), and renal function (HAS2 and HAS2-AS1, SLIT3). Collectively, these findings suggest a role of educational attainment or SES in further dissection of the genetic architecture of BP.
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| 9. |
- de Vries, Paul S., et al.
(författare)
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Multiancestry Genome-Wide Association Study of Lipid Levels Incorporating Gene-Alcohol Interactions
- 2019
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Ingår i: American Journal of Epidemiology. - : Oxford University Press. - 0002-9262 .- 1476-6256. ; 188:6, s. 1033-1054
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Tidskriftsartikel (refereegranskat)abstract
- A person's lipid profile is influenced by genetic variants and alcohol consumption, but the contribution of interactions between these exposures has not been studied. We therefore incorporated gene-alcohol interactions into a multiancestry genome-wide association study of levels of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. We included 45 studies in stage 1 (genome-wide discovery) and 66 studies in stage 2 (focused follow-up), for a total of 394,584 individuals from 5 ancestry groups. Analyses covered the period July 2014-November 2017. Genetic main effects and interaction effects were jointly assessed by means of a 2-degrees-of-freedom (df) test, and a 1-df test was used to assess the interaction effects alone. Variants at 495 loci were at least suggestively associated (P < 1 x 10(-6)) with lipid levels in stage 1 and were evaluated in stage 2, followed by combined analyses of stage 1 and stage 2. In the combined analysis of stages 1 and 2, a total of 147 independent loci were associated with lipid levels at P < 5 x 10(-8) using 2-df tests, of which 18 were novel. No genome-wide-significant associations were found testing the interaction effect alone. The novel loci included several genes (proprotein convertase subtilisin/kexin type 5 (PCSK5), vascular endothelial growth factor B (VEGFB), and apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1 (APOBEC1) complementation factor (A1CF)) that have a putative role in lipid metabolism on the basis of existing evidence from cellular and experimental models.
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| 10. |
- An, Sining, 1991, et al.
(författare)
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A 40 Gbps DQPSK Modem for Millimeter-wave Communications
- 2016
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Ingår i: Asia-Pacific Microwave Conference Proceedings APMC 2015. ; 1
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Konferensbidrag (refereegranskat)abstract
- A high speed differential quadrature phase shift keying (DQPSK) modulator and demodulator (modem) is presented for data rates up to 40 Gbps, in which the modulator is based on an FPGA and the demodulator is based on analog components. The modem performance has been verified in a lab environment. The targeted application is wireless communications using millimeter-wave bands as a flexible alternative to optical fiber links in next generation mobile networks.
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| 11. |
- An, Sining, 1991, et al.
(författare)
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An 8 Gbps E-band QAM Transmitter Using Symbol-based Outphasing Power Combining Technique
- 2017
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Ingår i: Radio-Frequency Integration Technology (RFIT2017). - 9781509040360 ; , s. 150-152
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Konferensbidrag (refereegranskat)abstract
- In millimeter-wave communication systems, generating high output power with high efficiency on the transmitter side is one major challenge. In this paper, a symbol-based outphasing power combining solution has been demonstrated with data rate up to 8 Gbps at an RF frequency of 83.5 GHz. This solution provides 2 dB higher output power compared to the power of two QAM signals at 12% EVM.
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| 12. |
- Bao, Mingquang, 1962, et al.
(författare)
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A High-Speed Power Detector for D-Band Communication
- 2014
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 62:7, s. 1515-1524
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Tidskriftsartikel (refereegranskat)abstract
- A D-band power detector (PD) consisting of a four-way power divider and four identical active PD units is proposed, where four individual PD units are derived by the input signals having the same amplitude, but a 90 degrees phase difference. The outputs of the PD units are combined, to suppress the first, second, and third harmonics due to phase cancellation. Consequently, the ripple at the output is minimized. The proposed PD is designed and manufactured in a 0.25-mu m InP DHBT technology, which is characterized by on-chip measurements with both a sinusoidal signal and a binary amplitude shift-keying modulated signal at a data rate up to 13 Gb/s over different carrier frequencies from 100 to 150 GHz. Measured bit error rate for a 2(7) - 1 pseudorandom binary sequence is less than 10(-12) at the carrier frequency of 120 GHz, and less than 1.7 x 10(-5) at the carrier frequency of 150 GHz. In addition, the proposed PD achieves state-of-the-art power/energy efficiency, which exhibits the lowest energy per bit of 1.1 pJ/bit. Total dc power consumption of the PD is 15 mW.
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| 13. |
- Bi, Zhenwang, et al.
(författare)
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Prevalence of the mcr-1 colistin resistance gene in extended-spectrum beta-lactamase-producing Escherichia coli from human faecal samples collected in 2012 in rural villages in Shandong Province, China
- 2017
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Ingår i: International Journal of Antimicrobial Agents. - : ELSEVIER SCIENCE BV. - 0924-8579 .- 1872-7913. ; 49:4, s. 493-497
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Tidskriftsartikel (refereegranskat)abstract
- Since its initial discovery in China in 2015, the plasmid-mediated colistin resistance gene mcr-1 has been reported in Escherichia coli isolated from clinical samples, animals and meat worldwide. In this study, 706 extended-spectrum beta-lactamase (ESBL)-producing E. coli from 411 persons were detected in a collection of faecal samples from 1000 rural residents in three counties in Shandong Province, China. These isolates were screened for mcr-1 and phenotypic colistin resistance. The gene was found in 3.5% of the isolates (from 4.9% of persons) from all three counties. All isolates with phenotypic colistin resistance carried mcr-1. These data indicate that commensal carriage of ESBL-producing E. coli with mcr-1 among persons in rural China was already present in 2012 and that mcr-1 was the most important colistin resistance mechanism. Interventions are necessary to minimise further dissemination of mcr-1, which would limit the future usefulness of colistin as a last-resort antibiotic. (C) 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.
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| 14. |
- Chen, Jingjing, 1982, et al.
(författare)
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10 Gbps 16QAM transmission over a 70/80 GHz (E-band) radio test-bed
- 2012
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Ingår i: European Microwave Week 2012: "Space for Microwaves", EuMW 2012, Conference Proceedings - 7th European Microwave Integrated Circuits Conference, EuMIC 2012. - : IEEE. - 9782874870286 - 9781467323024 - 9782874870262 ; , s. 556-559
-
Konferensbidrag (refereegranskat)abstract
- A millimeter-wave radio test-bed is implemented which demonstrates 16QAM transmission over 70/80 GHz band for data rate up to 10 Gbps. Performance of the 16QAM transmitter and receiver is evaluated in a loop-back lab set-up. With the proposed 10 Gbps on single carrier system architecture, it is possible to achieve 40 Gbps over a 5 GHz bandwidth when combined with polarization and spatial multiplexing.
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| 15. |
- Chen, Jian, et al.
(författare)
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A coupled DEM-SPH model for moisture migration in unsaturated granular material under oscillation
- 2020
-
Ingår i: International Journal of Mechanical Sciences. - : Elsevier. - 0020-7403 .- 1879-2162. ; 169
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Tidskriftsartikel (refereegranskat)abstract
- Granular materials, such as mineral products, soil and chemical fertilizer, normally contain unsaturated free moisture. This unsaturated moisture could migrate in the granular material and its processing, resulting in handling and safety concerns due to a change in the material properties. In this work, a method of coupling the Discrete Element Method (DEM) and the Smoothed Particle Hydrodynamics (SPH) was proposed to investigate moisture migration in unsaturated granular materials under oscillation. The particles and water were simulated through DEM and SPH, respectively and a python coupling framework was programmed to perform the exchange of particle-fluid interaction forces. Subsequently, experiments with plastic pellets and a coal sample were used to calibrate the models, with DEM calibrated by an angle of repose experiment and draining experiments calibrating the coupled model. Finally, the coupled model was validated by comparing the results to those of experiments involving moisture migration under oscillation. It was found that, compared to measurements, the coupled SPH-DEM model predicted the same moisture migration trend and also provided good agreement for the prediction of the mass of drained water.
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| 16. |
- Chen, Jingjing, 1982, et al.
(författare)
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A data-rate adaptable modem solution for millimeter-wave wireless fronthaul networks
- 2015
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Ingår i: 2015 IEEE International Conference on Communication Workshop, ICCW 2015. - 2164-7038. - 9781467363051 ; , s. 1-6
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Konferensbidrag (refereegranskat)abstract
- For dense small cell deployment in centralized baseband architecture, wireless fronthaul is a cost efficient and flexible alternative to fiber-based fronthaul links. Due to the available wide bandwidth, millimeter-wave technology is the most promising choice to realize multi-gigabit wireless transmission of the common public radio interface (CPRI). In this paper, we present a novel differential encoding scheme for differential quadrature phase-shift keying (D-QPSK) modulation, which enables data-rate adaptable CPRI transmission without modification of a standard receiver. A multi-rate D-QPSK modulator/demodulator (modem) is implemented and tested for data rates up to 10 Gbps, limited by the bandwidth of the microwave components in use. This modem is verified to fulfill the CPRI specifications with respect to multi-rate, low latency and high system performance. Therefore, it is proposed for the implementation of wireless CPRI links at millimeter-wave bands.
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| 17. |
- Chen, Jingjing, et al.
(författare)
-
A high efficient heat exchanger with twisted geometries for biogas process with manure slurry
- 2020
-
Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 279
-
Tidskriftsartikel (refereegranskat)abstract
- Heat-transfer enhancement in manure slurry is crucial for increasing the efficiency and production of biogas during anaerobic digestion in biogas plants. In this study, a novel heat exchanger with an optimal twisted geometry was developed based on the numerical screening of the twisted tubes with equilateral polygons, and experiments were conducted to validate the numerical results. It was observed that the SST k-ω model is more efficient than other turbulence models in representing the heat transfer performance of the twisted tubes, and the numerical model with a thermostatic wall can be used to reliably screen the twisted geometries. The twisted hexagonal tube has the optimal geometry, with enhancement capability of up to 1.4 times compared to that of the circular tube. The formation of high continuity regions with relatively strong heat-transfer rates along the heat-exchange wall is the main reason for the high performance during heat transfer. The external heating process was integrated in a full-scale biogas plant, and the model and algorithm were developed and validated with additional experiments to describe the overall performance of both conventional and screened optimal geometries under different conditions. It was observed that a profit equivalent to 39% of total production for a large-scale biogas plant can be achieved owing to energy conservation in external heating with the twisted hexagonal tubes.
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| 18. |
- Chen, Jingjing, 1982, et al.
(författare)
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An Energy Efficient 56 Gbps PAM-4 VCSEL Transmitter Enabled by a 100 Gbps Driver in 0.25 µm InP DHBT Technology
- 2016
-
Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 34:21, s. 954-4964
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Tidskriftsartikel (refereegranskat)abstract
- Datacenters demand higher speed VCSEL-based optical interconnects at low power consumption. As a potential technology enabler, this paper presents a wide bandwidth and energy efficient multilevel PAM VCSEL driver implemented in an InP 0.25 μm double heterojunction bipolar transistor (DHBT) technology. The operational bandwidth of the driver is verified and error-free electrical data transmission up to 56 Gbps PAM-2 and 100 Gbps PAM-4 is demonstrated at a driver energy consumption less than 2 pJ/bit. The driver is integrated and tested with an in-house fabricated 850 nm VCSEL. Error-free 56 Gbps PAM-4 optical transmission at a transmitter energy consumption of 3.7 pJ/bit is demonstrated without equalization. This is the highest data rate reported for an integrated PAM-4 modulated VCSEL transmitter, while being the most energy efficient above 40 Gbps operation. Moreover, the VCSEL driver offers a pre-emphasis feature at PAM-2 operation for improved link throughput and receiver sensitivity.
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| 19. |
- Chen, Jingjing, 1982, et al.
(författare)
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Demonstration of analog millimeter-wave fronthaul for 64-QAM LTE transmission
- 2015
-
Ingår i: IEEE Vehicular Technology Conference. - 1550-2252.
-
Konferensbidrag (refereegranskat)abstract
- Centralized baseband architecture is believed to be cost efficient and to offer high network performance. The fronthaul network, connecting the centralized baseband to distributed remote radios, requires high capacity and low latency transport links, due to the stringent specifications of the data interface, known as common public radio interface (CPRI). Today, fronthaul links are mostly based on digital CPRI over fibers, although it is possible to realize CPRI over wireless technology with the drawback of poor bandwidth efficiency. In this paper, we propose an analog wireless fronthaul concept to enable bandwidth efficient and scalable fronthaul networks. The basic idea is to transport narrow band analog radio signals over millimeter-wave bands instead of multi-gigabit digital signals. The phase and frequency impairments introduced by high frequency carriers are effectively reduced using an analog pilot-based mitigation technique. As a proof-of-concept demonstration, an analog fronthaul link is implemented, and the link performance is verified for 20 MHz 64-QAM LTE transmission over 70/80 GHz (E-band). The measured error vector magnitude (EVM) is about 3% with 10% pilot bandwidth overhead.
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| 20. |
- Chen, Jingjing, et al.
(författare)
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Designing heat exchanger for enhancing heat transfer of slurries in biogas plants
- 2019
-
Ingår i: Innovative Solutions for Energy Transitions. - : Elsevier. ; , s. 1288-1293
-
Konferensbidrag (refereegranskat)abstract
- Heat transfer geometries with enhanced performance for the slurries with high viscosity can improve the net raw biogas production in bio-methane process. In this study, the rheological properties of different slurries were tested, correlated and implemented to computational fluid dynamics (CFD). CFD was then used to screen a new geometry based on the twisted tube combined with mechanism study, and experimental testing was conducted for verification. It shows that the twisted hexagonal tube (THT) has the highest performance. The mechanism for enhancing the heat transfer with THT was mainly due to the effective shear rate. Furthermore, the waste-heat recovery with the THT heat exchanger in biogas production was estimated quantitatively and compared with the normal heat exchanger and scraped-surface heat exchanger (SSHE). Compared to the normal heat exchanger, for THT, the increase of net raw biogas production δNRBP can be up to 17%, while it is only up to 8.53% for SSHE. Besides, the external heating up processes with THT and normal heat exchanger were studied to estimate the heating time for different temperature fluctuations and power requirements of boiler. It is found that the process with THT can save 25-38% heating time for the anaerobic reactor compared to the normal heat exchanger. Therefore, designed THT heat exchanger is promising, and the developed methods can also be beneficial for studying other heat transfer processes.
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| 21. |
- Chen, Jingjing, 1982, et al.
(författare)
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Does LO Noise Floor Limit Performance in Multi-Gigabit Millimeter-Wave Communication?
- 2017
-
Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 27:8, s. 769-771
-
Tidskriftsartikel (refereegranskat)abstract
- Extremely high data rate communication can potentially be achieved by combining high-order modulations and wide bandwidths at millimeter-wave (mm-wave) frequencies. However, it has been challenging to practically implement this combination, even if the SNR of the system appears to be sufficiently high. An explanation from a recent theoretical study is that the practical data rates in mm-wave systems are limited by the local oscillator (LO) white phase noise. In this letter, we present an experimental investigation on whether the white noise floor of frequency multiplied LO sources is a major noise contribution to wideband signals. Hardware measurements are performed using multi-gigabit 64 quadrature amplitude modulation (QAM) signals. The measured results show that the transmitter performance degrades as the LO noise floor increases. Hence, the LO noise floor is identified to be one primary limitation for achieving the highest possible data rate in wideband mm-wave systems.
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| 22. |
- Chen, Jingjing, 1982, et al.
(författare)
-
Experimental demonstration of RF-pilot-based phase noise mitigation for millimeter-wave systems
- 2014
-
Ingår i: IEEE Vehicular Technology Conference. - 1550-2252. - 9781479944491 ; , s. Art. no. 6965978-
-
Konferensbidrag (refereegranskat)abstract
- Millimeter-wave bands are gaining popularity for high data rate wireless communication systems due to the wide available bandwidth. However, oscillator phase noise also increases as the carrier frequency increases. Methods of phase noise mitigation are therefore crucial for future millimeter-wave systems. In this work, we propose to adopt analog phase noise mitigation using an RF-pilot tone, which reduces both phase and frequency impairments of an arbitrary millimeter-wave signal at the expense of reduced spectral efficiency. The method is verified experimentally at carrier frequency of 28 GHz and E-band 73 GHz showing a 20 dB noise reduction up to 100 kHz offset. Since the method relaxes phase noise requirement it is attractive for phase noise sensitive technologies at high carrier frequency, such as OFDM used in LTE. As indicated by the simulation results, the reduced phase noise enables a LTE signal on a millimeter-wave carrier with marginal performance impact.
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| 23. |
- Chen, Jingjing, et al.
(författare)
-
Heat-transfer enhancement for corn straw slurry from biogas plants by twisted hexagonal tubes
- 2020
-
Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 262
-
Tidskriftsartikel (refereegranskat)abstract
- Heat-transfer geometries that enhance heat transfer performance for slurries increase the net raw biogas production in the bio-methane process. In this study, the precise temperature-dependent rheologies of corn straw slurry with 6 and 8% total solid were determined, collected, and modeled to conduct a numerical simulation via CFD, the first instance of such research. Subsequently, the reliability of the numerical results was verified with heat-transfer experiments. The heat-transfer performances of the circular, twisted square and twisted hexagonal tubes were estimated numerically, ultimately showing that the twisted hexagonal tube performed optimally with an enhancement factor of up to 2.0 in the turbulent region, compared to the circular tube. Based on the numerical results, the mechanism of heat-transfer enhancement was revealed, showing balanced radial mixing and the near-wall shear effect that leads to a strong and continuous shear rate under a considerable radial-flow intensity. An engineering equation was obtained for the performance evaluation, and the waste-heat recovery from corn straw slurry was analyzed, showing the twisted hexagonal tube can increase the net raw biogas production by up to 17.0% compared to the circular tube.
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| 24. |
- Chen, Jingjing
(författare)
-
Heat-transfer Enhancement for Slurries from Biogas Plants− Properties, processes, and thermal systems
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Biomethane production from renewable residues with anaerobic digestion gains increasing attention as a crucial alternative to petroleum fuels. It has been vigorously developed, but the large amounts of subsidy from the government indicate that the process efficiency needs to be further improved. For biomethane production, on the one hand, a great amount of heat needs to be used for heating the feeding slurry, sanitation of slurry, and maintaining the temperature in the large-scale reactors. On the other hand, a large amount of thermophilic effluent slurries brings a huge amount of waste heat, which can be recovered. This makes it important to study how to increase production by improving the thermal efficiency of biogas plants with novel heat exchangers. The working fluids in the biogas plants are the non-Newtonian and high-viscous slurries, and the conventional heat exchangers in biogas plants always show much lower performance compared to those in other industries. Normally, the slurries in the biogas plant consist of different substrates, including straw, manure, food waste, municipal sludge, and their mixtures, and various factors such as the amount and type of solids, particle size, shear rate, and temperature impact the rheological properties of the slurries, which makes the complexity in the rheological properties and the difficulty in developing novel heat exchangers.The development of heat exchangers calls for the rheological properties of slurries. However, to the best of our knowledge, only the rheology of manure slurry was systematically determined and modeled considering the effect of temperature. The lack of the rheological properties of slurries further hinders the design and development of novel geometries to enhance the heat transfer of the slurries. Correspondingly, the quantitative contribution and potential of the waste-heat recovery from the slurries to production using the enhanced geometry remain unclear. In this thesis work, to design novel geometry with heat-transfer enhancement for different slurries and determine its potential in thermal cycles in the full-scale biogas plants, firstly, the temperature-dependent rheological properties of the slurries, including the corn straw, food waste, and mixed slurries, were tested and modeled. It was found that these slurries possess strong shear-thinning behavior, the temperature has a significant impact on their dynamic viscosity, and the power-law model combined with the Arrhenius equation can describe the rheology well. Subsequently, with the reliable models of the rheological properties as the key input, Computational Fluid Dynamics simulations were conducted to screen different twisted geometries, determine the heat-transfer performance, and reveal the mechanism of the heat-transfer enhancement. Lab- and pilot-scale experiments were also conducted to validate the numerical results. The twisted hexagonal tubes show a positive enhancement factor up to 2.6 compared to normal heat exchangers in a wide range of operating conditions. The continuous and strong near-wall shear effect is the intrinsic reason for achieving a significant heat-transfer enhancement in the twisted hexagonal tubes. Moreover, the generalized engineering equations for predicting the effective shear rate and heat-transfer performance with measurable parameters were established and verified with both numerical and experimental results. Finally, the twisted-hexagonal-tube heat exchange was integrated with complete thermal cycles, including waste-heat recovery and external heating processes in the biogas plant, and the potential of increased production and profits were modeled and analyzed combined with the practical operating conditions in a full-scale biogas plant. It was found that for the waste-heat recovery using the twisted hexagonal tubes, the net raw biogas production can increase by up to 17.0 %, and for the external heating process, the increased profit equivalent to 39 % of total production can be achieved owing to energy conservation in external heating using the twisted-hexagonal-tube heat exchangers for a full-scale biogas plant.
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| 25. |
- Chen, Jingjing, et al.
(författare)
-
Heat-transfer Enhancement with Pulsating Flow in Twisted Hexagonal Tube for Manure Slurry from Biogas Plants
- 2020
-
Ingår i: Proceedings of 12th International Conference on Applied Energy. - : Applied Energy Innovation Institute (AEii).
-
Konferensbidrag (refereegranskat)abstract
- Biogas is one of the most crucial renewable energy and achieving high-efficient heat exchangers is the key to improve its production. In this study, the effect of pulsating flow on heat transfer in a twisted hexagonal tube with manure slurry was investigated for the first time by using computational fluid dynamics CFD. The performances of pulsating flows were simulated under different conditions, including the inlet velocity, frequency, and amplitude of pulsating flow in the twisted hexagonal tube with different torques. Pressure drops at different frequencies were further investigated. Moreover, the mechanism of heat-transfer enhancement was revealed with the evolution of the heat-transfer coefficient over time. It was found the pulsating flow achieves an 18.9% enhancement at low torque.
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| 26. |
- Chen, Jingjing, et al.
(författare)
-
Heat-transfer performance of twisted tubes for highly viscous food waste slurry from biogas plants
- 2022
-
Ingår i: Biotechnology for Biofuels and Bioproducts. - : Springer Nature. - 2731-3654. ; 15
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The use of food waste as feedstock shows high production of biogas via anaerobic digestion, but requires efficient heat transfer in food waste slurry at heating and cooling processes. The lack of rheological properties hampered the research on the heat-transfer process for food waste slurry. Referentially, the twisted hexagonal and elliptical rubes have been proved as the optimal enhanced geometry for heat transfer of medium viscous slurries with non-Newtonian behavior and Newtonian fluids, respectively. It remains unknown whether improvements can be achieved by using twisted geometries in combination with food waste slurry in processes including heating and cooling.Results: Food waste slurry was observed to exhibit highly viscous, significant temperature-dependence, and strongly shear-thinning rheological characteristics. Experiments confirmed the heat-transfer enhancement of twisted hexagonal tubes for food waste slurry and validated the computational fluid dynamics-based simulations with an average deviation of 14.2%. Twisted hexagonal tubes were observed to be more effective at low-temperature differences and possess an enhancement factor of up to 2.75; while twisted elliptical tubes only exhibited limited heat-transfer enhancement at high Reynolds numbers. The heat-transfer enhancement achieved by twisted hexagonal tubes was attributed to the low dynamic viscosity in the boundary layer induced by the strong and continuous shear effect near the walls of the tube.Conclusions: This study determined the rheological properties of food waste slurry, confirmed the heat-transfer enhancement of the twisted hexagonal tubes experimentally and numerically, and revealed the mechanism of heat-transfer enhancement based on shear rate distributions.
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| 27. |
- Chen, Jingjing, 1982, et al.
(författare)
-
Influence of White LO Noise on Wideband Communication
- 2018
-
Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 66:7, s. 3349-3359
-
Tidskriftsartikel (refereegranskat)abstract
- Applying a spectrally efficient modulation to a wideband signal provides an extremely high data rate potential in millimeter-wave communication. In reality, wideband systems, as reported in open literature, typically suffer from insufficient signal-to-noise ratio (SNR) and thus are not able to support high-order modulation. In a recent experimental study, we have identified that a high noise floor from frequency-multiplied local oscillator (LO) sources is a major data rate limitation in wideband systems. In this paper, we present a detailed study with a mathematical model to describe the influence of the LO noise on a communication signal through frequency conversion. Followed by experimental investigations using multigigabit 64-quadrature amplitude modulation signals, measurements are performed at frequency up- and down-conversions. Both cases show SNR degradation on the frequency-converted signals as the corresponding LO noise floor increases. We provide experimental proof that the nature of the LO noise floor is white, with nearly the same amount of phase and amplitude noises. Various ways to reduce the white LO noise floor through the new hardware design are discussed providing design requirements and considerations.
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| 28. |
- Chen, Jingjing, et al.
(författare)
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Mechanism of waste-heat recovery from slurry by scraped-surface heat exchanger
- 2017
-
Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 207, s. 146-155
-
Tidskriftsartikel (refereegranskat)abstract
- Waste-heat recovery from discharged slurries can improve the net raw biogas production in the bio-methane process in order to meet the demand for a next-generation of anaerobic digestion. In this study, a numerical model of a scraped-surface heat exchanger was proposed with the consideration of the complete and precise rheological behaviour of the slurry of animal manure for the first time for achieving highly efficient waste-heat recovery. The rheological model results were verified with new experimental data measured in this work. Subsequently, the convective heat-transfer coefficient of the scraped-surface heat exchanger was calculated numerically with the proposed numerical model, and the performance was determined. Then, the contributions of waste-heat recovery from the slurry to the biogas production using a general shell-and-tube heat exchanger and the scraped-surface heat exchanger were calculated quantitatively and compared. For the case of scraped-surface heat exchanger, the increase of net raw biogas production can be up to 8.53%, which indicates that there is a great potential to increase the net raw biogas production in the bio-methane process using a scraped-surface heat exchanger with low-cost equipment and a compactible structure.
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| 29. |
- Chen, Jingjing, et al.
(författare)
-
Mechanism Study of Heat Transfer Enhancement Using Twisted Hexagonal Tube with Slurry from Biogas Plant
- 2017
-
Ingår i: Energy Procedia. - : Elsevier. - 1876-6102. ; 142, s. 880-885
-
Tidskriftsartikel (refereegranskat)abstract
- Waste-heat recovery from discharged slurries is important to improve the biogas production efficiency but still remains challenge duo to the special properties of slurries in anaerobic digestion process. In this work, numerical study was carried out to investigate the flow field, and heat transfer performance of slurry from biogas plant in the twisted hexagonal and other twisted tubes was simulated with computer fluid dynamic (CFD) for the first time. The numerical method was validated with experimental data from the literature. The heat transfer performance and flow resistance of twisted hexagon tube were calculated and compared with other types of twisted tubes. The enhancement factor of the twisted hexagonal tube reached to 2 and kept optimum at turbulence flow region compared to the twisted tubes with square and elliptical cross section. Meanwhile, the mechanism of heat transfer enhancement with different twisted tubes was further studied, and the optimal field synergy and minimum local circulation flow near the wall are the main reasons for the high performance and low flow resistance of the twisted hexagonal tube.
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| 30. |
- Chen, Jingjing, et al.
(författare)
-
Mechanism Study of Waste Heat Recovery from Slurry by Surface Scraped Heat Exchanger
- 2017
-
Ingår i: Energy Procedia. - : Elsevier. - 1876-6102. ; 105, s. 1109-1115
-
Tidskriftsartikel (refereegranskat)abstract
- Waste-heat recovery from discharged slurries can improve the net raw biogas production in bio-methane process in order to meet the demand of a new generation of anaerobic digestion. In order to achieve a high efficient waste-heat recovery, in this work, a mathematical model of waste-heat recovery process with surface scraped heat exchanger (SSHE) was proposed with the consideration of the shear rate and temperature-dependent rheological behaviour. The convective heat transfer performance of SSHE was calculated numerically where slurry was considered. The contribution of waste heat recovery from the slurry to biogas production by SSHE and general shell-and-tube heat exchanger (STHE) were firstly calculated quantitatively, and the increase of net raw biogas production could be over 13.5% by SSHE with need of heat exchange area less than a quarter of STHE's, which showed a great potential to increase the net raw biogas production in bio-methane process with low equipment investments and more compactible structure.
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| 31. |
- Chen, Jingjing, 1982
(författare)
-
Multi-Gigabaud Millimeter-Wave Communication - Challenges and Solutions
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A major challenge in future mobile networks is to overcome the capacity barrier in wireless communication. Utilizing large bandwidth at higher frequencies is key to enabling capacity upgrade for next generation mobile networks (5G). As expected, multi-gigabit wireless communication is needed to support future 5G networks, particularly in the transport capacity of wireless backhaul and fronthaul. To be futureproof, wireless technologies towards 100 Gbps are of great interest. Millimeter-wave (mm-wave) frequency bands (30 to 300 GHz) have sufficient bandwidth to support these high data rates. However, due to hardware limitations, it is challenging to implement multi-GHz modulation bandwidth in actual hardware. For example, limited by the sampling rate of analog-to-digital and digital-to-analog converters, conventional digital modulator and demodulator (modem) designs cannot be applied to the very wide bandwidth required. As proof-of-concept, this thesis presents modems with multi-GHz bandwidth capability [A, B, C, D, E], as required for further capacity enhancement when combined with high-order modulations. The solutions in [C, D, E] do not require any data converters, therefore state-of-the-art energy efficiency is achieved [D, E]. The digital receiver in [B], on the other hand, relaxes requirements on the sampling speed thus being cost and power efficient. Enabled by the proposed modems, multi-gigabit transmission is demonstrated over mm-wave bands [B, C, E] and a short-range optical link [D].Another aspect that limits the practical use of mm-wave is the degradation of the communication signal quality due to high-frequency hardware impairments. In particular, oscillator phase noise increases with the carrier frequency. An analog phase noise mitigation technique is proposed for arbitrary mm-wave signal waveforms [F]. As a new system application, an analog fronthaul radio link is enabled by implementing phase noise mitigation, where LTE transmission is demonstrated at 70/80 GHz as a step towards future 5G systems [G]. To reach 100 Gbps and beyond, despite the wide bandwidth available at mm-wave bands, the simultaneous use of high-order modulations is also required. However, it is primarily the oscillator noise floor that prevents this combination from being successfully achieved, as confirmed in measurements [H]. A new understanding of performance limitation in wideband communication is provided in a detailed study [I], with guidelines on how to improve hardware designs.
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| 32. |
- Chen, Jingjing, 1982
(författare)
-
Multi-Gigabit Radio System Demonstrators for Next Generation Mobile Networks
- 2015
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Driven by the exponential growth in mobile broadband subscriptions and mobile data traffic, transport capacity of mobile networks has to be enhanced accordingly, including wireless backhaul and the emerging fronthaul networks. Utilizing wide bandwidth is the most straightforward way to capacity upgrade. Millimeter-wave frequency bands with large available bandwidth offer the opportunities to realize high capacity wireless links. However, there are challenges associated with the radio link implementation. For example, wide bandwidth is required for components like low noise amplifiers, power amplifiers, modulators and demodulators (modems). Another challenge is the signal quality degradation due to high frequency impairments.The solutions presented in the thesis are applicable to implementations based on commercially available hardware. Multi-gigabit modems are proposed using simple modulation differential quadrature phase shift keying (DQPSK), which do not need carrier recovery and power hungry mixed signal devices. To improve spectral efficiency, a 16-QAM modem is designed with optimized hardware efficiency. This in turn relaxes the demand on the sampling rate of analog to digital converters (ADC) and the resource requirement on digital signal processing. As proof-of-concept demonstration, DQPSK modems are implemented and verified at 2.5 and 5 Gbps. A 5 Gbps radio system based on the hardware efficient 16-QAM modem is also demonstrated at 70/80 GHz (E-band). The presented modems and systems address challenges in applying wide bandwidth/high symbol rate to realizing high capacity. Moreover, it defines the baseline for further capacity enhancement when combined with high spectral efficiency techniques.Besides the mobile backhaul application, high capacity wireless links are required to support the mobile fronthaul as a new network segment, which connects a centralized baseband pool to distributed remote radio units. A data-rate adaptable DQPSK modem solution is proposed for digital wireless fronthaul to transmit multi-gigabit CPRI (common public radio interface). An E-band digital fronthaul link is implemented using this modem at 5 Gbps. To overcome the low bandwidth efficiency of the digital fronthaul, an analog fronthaul technology is introduced as an enabler for cost efficient and scalable fronthaul networks. An analog fronthaul link is demonstrated at E-band complemented with phase noise mitigation for 64-QAM LTE transmission.
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| 33. |
- Chen, Jingjing, et al.
(författare)
-
Slippage on Porous Spherical Superhydrophobic Surface Revolutionizes Heat Transfer of Non-Newtonian Fluid
- 2022
-
Ingår i: Advanced Materials Interfaces. - : John Wiley & Sons. - 2196-7350. ; 9:34
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, a new strategy to achieve high-efficient heat transfer for non-Newtonian fluids with slippage using a stably prepared superhydrophobic coating is presented. A superhydrophobic coating is prepared on the inner surface of a sleeve at specific shear stress. The slippage and heat-transfer processes of the typical non-Newtonian fluid–1% carboxymethyl cellulose solutions on the superhydrophobic coating are investigated simultaneously. A novel porous spherical type of superhydrophobic coating with a contact angle of 168° is obtained. It is found that the shear stress in electrodeposition is a key parameter to control the morphology and wetting ability of the superhydrophobic coating. The slip length and enhancement factor of heat transfer for the non-Newtonian fluid on the coating are found in a range of 20–900 µm and 1.47 experimentally. A new parameter is proposed as Reynolds number Re divided by the dimensionless slip length ls* (Re/ls*) for the heat-transfer enhancement with slippage, which can be used as the guide for designing coating and selecting the operating conditions. The Re/ls* is <4, which can enhance the heat transfer via the slippage.
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| 34. |
- Chen, Kuan, et al.
(författare)
-
Characterization and protein engineering of glycosyltransferases for the biosynthesis of diverse hepatoprotective cycloartane-type saponins in Astragalus membranaceus
- 2023
-
Ingår i: Plant Biotechnology Journal. - : John Wiley & Sons. - 1467-7644 .- 1467-7652. ; 21:4, s. 698-710
-
Tidskriftsartikel (refereegranskat)abstract
- Although plant secondary metabolites are important source of new drugs, obtaining these compounds is challenging due to their high structural diversity and low abundance. The roots of Astragalus membranaceus are a popular herbal medicine worldwide. It contains a series of cycloartane-type saponins (astragalosides) as hepatoprotective and antivirus components. However, astragalosides exhibit complex sugar substitution patterns which hindered their purification and bioactivity investigation. In this work, glycosyltransferases (GT) from A. membranaceus were studied to synthesize structurally diverse astragalosides. Three new GTs, AmGT1/5 and AmGT9, were characterized as 3-O-glycosyltransferase and 25-O-glycosyltransferase of cycloastragenol respectively. AmGT1(G146V/I) variants were obtained as specific 3-O-xylosyltransferases by sequence alignment, molecular modelling and site-directed mutagenesis. A combinatorial synthesis system was established using AmGT1/5/9, AmGT1(G146V/S) and the reported AmGT8 and AmGT8(A394F). The system allowed the synthesis of 13 astragalosides in Astragalus root with conversion rates from 22.6% to 98.7%, covering most of the sugar-substitution patterns for astragalosides. In addition, AmGT1 exhibited remarkable sugar donor promiscuity to use 10 different donors, and was used to synthesize three novel astragalosides and ginsenosides. Glycosylation remarkably improved the hepatoprotective and SARS-CoV-2 inhibition activities for triterpenoids. This is one of the first attempts to produce a series of herbal constituents via combinatorial synthesis. The results provided new biocatalytic tools for saponin biosynthesis.
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| 35. |
- Cheng, Li, et al.
(författare)
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Safety and Protection Measures of Underground Non-Coal Mines with Mining Depth over 800 m: A Case Study in Shandong, China
- 2022
-
Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 14:20
-
Tidskriftsartikel (refereegranskat)abstract
- With the increase in mining depth, the risk of ground pressure disasters in yellow gold mines is becoming more and more serious. This paper carries out a borehole test for the pressure behavior in a non-coal mining area with a mining depth of more than 800 m in the Jiaodong area. The test results show that under a depth of 1050 m, the increase in the vertical principal stress is the same as the increase in the minimum horizontal principal stress, which is about 3 MPa per 100 m. When the depth increases to 1350 m, the vertical principal stress increases by about 3% per 100 m, and the self-weight stress and the maximum horizontal principal stress maintain a steady growth rate of about 3 MPa per 100 m. In addition, based on the test results, the operation of the ground pressure monitoring system in each mine is investigated. The investigation results show that in some of the roadway and stope mines with depths of more than 800 m, varying degrees of rock mass instability have occurred, and a few mines have had sporadic slight rockbursts, accounting for about 5%. There was a stress concentration area in the lower part of the goaf formed in the early stage of mining, and slight rockburst phenomena such as rock mass ejection have occurred; meanwhile, the area stability for normal production and construction was good, and there was no obvious ground pressure. This paper compares the researched mines horizontally as well as to international high-level mines and puts forward some suggestions, including: carrying out ground pressure investigations and improving the level of intelligence, which would provide countermeasures to balance the safety risks of deep mining, reducing all kinds of safety production accidents and providing a solid basis for risk prevention and supervision.
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| 36. |
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| 37. |
- Han, Ruiping, et al.
(författare)
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Review on Heat-Utilization Processes and Heat-Exchange Equipment in Biogas Engineering
- 2016
-
Ingår i: Journal of Renewable and Sustainable Energy. - : AIP Publishing. - 1941-7012. ; 8:3
-
Tidskriftsartikel (refereegranskat)abstract
- With the increasing demand for environmental protection and renewable energy, bioenergy technology has been attracting considerable attention. Anaerobic digestion (AD) is the process to convert the low-grade biomass into bioenergy, in which both heat-recovery and -recycling should be treated carefully in order to improve the process efficiency. In this work, the heat-recovery and its utilization processes were reviewed, and different types of heat exchangers as well as their advantages in biogas engineering were surveyed. It shows that the recovery and utilization of the waste heat from biogas plants with an internal system, such as slurry effluent unit, the combined heat and power unit, the sanitation unit, and the internal recycle unit, are important for improving the AD efficiency of biogas production. For example, the recovery and recycling of waste heat from the effluent can result in a 2-3 °C temperature increase for the inlet manure slurry. For thermophilic AD, the heat recovery from effluent can save about 50% of the total heat requirement. The external heating process is more suitable for large- and medium-scale biogas plants, and the heat transfer coefficient of external heating (850-1000 W/m2 K-1) is almost two-times higher than that of the internal heating (300-400 W/m2 K-1). To utilize the waste heat in biogas plants, heat exchangers have been designed for biogas slurry. However, further improvement on the heat exchangers with anti-blockage, anti-fouling, high efficiency, and low investment is still needed. Moreover, the heat exchanger suitable for a low-temperature-difference system is specially needed in China, but the development is still in its infancy. Therefore, to tailor to the Chinese national conditions, special external heating processes should be designed and reoriented to the diversity of biomass, the climatic environmental conditions, and the renewable Chinese policies
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| 38. |
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| 39. |
- He, Xin, et al.
(författare)
-
Worsening of Renal Function Among Hospitalized Patients With Acute Heart Failure: Phenotyping, Outcomes, and Predictors.
- 2022
-
Ingår i: Mayo Clinic proceedings. - : Elsevier BV. - 1942-5546 .- 0025-6196. ; 97:9, s. 1619-1630
-
Tidskriftsartikel (refereegranskat)abstract
- To define clinical phenotyping and its associated outcome of worsening of renal function (WRF) in hospitalized acute heart failure (AHF) patients.Latent class analysis was performed in 113 AHF patients who developed WRF within 72 hours in the DOSE (Diuretic Optimization Strategies Evaluation) trial (from March 2008 to November 2009) and ROSE-AHF (Renal Optimization Strategies Evaluation in Acute Heart Failure) trial (from September 2010 to March 2013) to identify potential WRF phenotypes. Clinical characteristics and outcome (in-hospital and post-discharge) were compared between different phenotypes.Two WRF phenotypes were identified by latent class analysis, which we named WRF minimally responsive to diuretics (WRF-MRD) and WRF responsive to diuretics (WRF-RD). Among the population, 58 (9.5%) developed WRF-MRD and 55 (9.0%) developed WRF-RD. Patients with WRF-MRD had more comorbidities than WRF-RD. In WRF-MRD, there were an early increase in serum creatinine, a smaller amount of net fluid loss and weight loss, and a higher rate of worsening or persistent heart failure over 72 hours. In contrast, for those with WRF-RD, they had faster in-hospital net fluid loss and weight loss and a better 60-day survival after discharge even compared with patients without WRF (P=.004). Furthermore, baseline chronic obstructive pulmonary disease, diabetes, and cystatin C were independent predictors of WRF-MRD, whereas serum hemoglobin and sodium predicted WRF-RD.Among hospitalized AHF patients, we identified two phenotypes of WRF with distinct response to heart failure treatment, predictors, and short-term prognosis after discharge. The results could help early differentiation of WRF phenotypes in clinical practice.
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| 40. |
- He, Zhongxia Simon, 1984, et al.
(författare)
-
A Hardware Efficient Implementation of a Digital Baseband Receiver for High-Capacity Millimeter-Wave Radios
- 2015
-
Ingår i: IEEE transactions on microwave theory and techniques. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9480 .- 1557-9670. ; 63:5, s. 1683-1692
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents an implementation solution for a digital baseband receiver, which consists mainly of an analog symbol timing recovery (STR) block and a digital carrier recovery block. The STR is realized based on "one-sample-per-symbol" sampling, resulting in relaxed requirement on the A/D converters sampling speed. In this sense, the proposed implementation solution is hardware efficient. To functionally verify the solution, a proof-of-concept E-band link system is implemented and tested in the laboratory, which supports 5-Gbit/s data traffic using 16 quadrature amplitude modulation. The test results demonstrate that the proposed solution works for high-capacity millimeter-wave radios for point-to-point links, one of the targeted applications.
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| 41. |
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| 42. |
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| 43. |
- Kozaki, Koichi, et al.
(författare)
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Blockade of platelet-derived growth factor or its receptors transiently delays but does not prevent fibrous cap formation in ApoE null mice.
- 2002
-
Ingår i: The American journal of pathology. - 0002-9440. ; 161:4, s. 1395-407
-
Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor (PDGF) is a potent stimulant of smooth muscle cell migration and proliferation in culture. To test the role of PDGF in the accumulation of smooth muscle cells in vivo, we evaluated ApoE -/- mice that develop complex lesions of atherosclerosis. Fetal liver cells from PDGF-B-deficient embryos were used to replace the circulating cells of lethally irradiated ApoE -/- mice. One month after transplant, all monocytes in PDGF-B -/- chimeras are of donor origin (lack PDGF), and no PDGF-BB is detected in circulating platelets, primary sources of PDGF in lesions. Although lesion volumes are comparable in the PDGF-B +/+ and -/- chimeras at 35 weeks, lesions in PDGF-B -/- chimeras contain mostly macrophages, appear less mature, and have a reduced frequency of fibrous cap formation as compared with PDGF-B +/+ chimeras. However, after 45 weeks, smooth muscle cell accumulation in fibrous caps is indistinguishable in the two groups. Comparison of elicited peritoneal macrophages by RNase protection assay shows an altered cytokine and cytokine receptor profile in PDGF-B -/- chimeras. ApoE -/- mice were also treated for up to 50 weeks with a PDGF receptor antagonist that blocks all three PDGF receptor dimers. Blockade of the PDGF receptors similarly delays, but does not prevent, accumulation of smooth muscle and fibrous cap formation. Thus, elimination of PDGF-B from circulating cells or blockade of PDGF receptors does not appear sufficient to prevent smooth muscle accumulation in advanced lesions of atherosclerosis.
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| 44. |
- Kristan, Matej, et al.
(författare)
-
The Visual Object Tracking VOT2013 challenge results
- 2013
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Ingår i: 2013 IEEE INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW). - : IEEE. - 9781479930227 ; , s. 98-111
-
Konferensbidrag (refereegranskat)abstract
- Visual tracking has attracted a significant attention in the last few decades. The recent surge in the number of publications on tracking-related problems have made it almost impossible to follow the developments in the field. One of the reasons is that there is a lack of commonly accepted annotated data-sets and standardized evaluation protocols that would allow objective comparison of different tracking methods. To address this issue, the Visual Object Tracking (VOT) workshop was organized in conjunction with ICCV2013. Researchers from academia as well as industry were invited to participate in the first VOT2013 challenge which aimed at single-object visual trackers that do not apply pre-learned models of object appearance (model-free). Presented here is the VOT2013 benchmark dataset for evaluation of single-object visual trackers as well as the results obtained by the trackers competing in the challenge. In contrast to related attempts in tracker benchmarking, the dataset is labeled per-frame by visual attributes that indicate occlusion, illumination change, motion change, size change and camera motion, offering a more systematic comparison of the trackers. Furthermore, we have designed an automated system for performing and evaluating the experiments. We present the evaluation protocol of the VOT2013 challenge and the results of a comparison of 27 trackers on the benchmark dataset. The dataset, the evaluation tools and the tracker rankings are publicly available from the challenge website(1).
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| 45. |
- Kristan, Matej, et al.
(författare)
-
The Visual Object Tracking VOT2016 Challenge Results
- 2016
-
Ingår i: COMPUTER VISION - ECCV 2016 WORKSHOPS, PT II. - Cham : SPRINGER INT PUBLISHING AG. - 9783319488813 - 9783319488806 ; , s. 777-823
-
Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2016 aims at comparing short-term single-object visual trackers that do not apply pre-learned models of object appearance. Results of 70 trackers are presented, with a large number of trackers being published at major computer vision conferences and journals in the recent years. The number of tested state-of-the-art trackers makes the VOT 2016 the largest and most challenging benchmark on short-term tracking to date. For each participating tracker, a short description is provided in the Appendix. The VOT2016 goes beyond its predecessors by (i) introducing a new semi-automatic ground truth bounding box annotation methodology and (ii) extending the evaluation system with the no-reset experiment.
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| 46. |
- Liu, Jingjing, et al.
(författare)
-
Effects of short-term motor training on accuracy and precision of simple jaw and finger movements after orthodontic treatment and orthognathic surgery : A case-control study
- 2023
-
Ingår i: Journal of Oral Rehabilitation. - : John Wiley & Sons. - 1365-2842. ; 50:8, s. 635-643
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Orthognathic surgery has been performed with increasing frequency for the treatment of severe malocclusion, yet the postsurgical neuromuscular recovery of patients has been inadequately studied.OBJECTIVE: To investigate the effect of short-term and simple jaw motor training on accuracy and precision of jaw motor control in patients following orthodontic treatment and orthognathic surgery.METHODS: ) to describe the motor performance. Furthermore, the changes in amplitude before and after training were measured in percentage.RESULTS: of simple jaw and finger movements significantly decreased after motor training (p ≤ .018) in all groups. The relative changes in finger movements were higher than jaw movements (p < .001) but with no differences among the groups (p ≥ .247).CONCLUSION: Both accuracy and precision of simple jaw and finger movements improved after short-term motor training in all three groups, demonstrating the inherent potential for optimization of novel motor tasks. Finger movements improved more than jaw movements but with no differences between groups, suggesting that changes in occlusion and craniofacial morphology are not associated with impaired neuroplasticity or physiological adaptability of jaw motor function.
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| 47. |
- Liu, Junwei, et al.
(författare)
-
Polymer synergy for efficient hole transport in solar cells and photodetectors
- 2023
-
Ingår i: Energy & Environmental Science. - : ROYAL SOC CHEMISTRY. - 1754-5692 .- 1754-5706.
-
Tidskriftsartikel (refereegranskat)abstract
- Hole transport materials (HTMs) have greatly advanced the progress of solution-based electronic devices in the past few years. Nevertheless, most devices employing dopant-free organic HTMs can only deliver inferior performance. In this work, we introduced a novel "polymer synergy" strategy to develop versatile dopant-free polymer HTMs for quantum dot/perovskite solar cells and photodetectors. With this synergy strategy, the optical, electrical and aggregation properties of polymer HTMs can be modulated, resulting in complementary absorption, high hole mobility, favorable energy landscape and moderate aggregation. Moreover, a clear orientational transition was observed for the developed HTMs with a 9-fold increase in the face-on/edge-on ratio, providing a highway-like carrier transport for electronic devices, as revealed by in situ characterization and ultrafast transient absorption. With these benefits, the photovoltaic and photodetection performance of quantum dot devices were boosted from 11.8% to 13.5% and from 2.95 x 10(12) to 3.41 x 10(13) Jones (over a 10-fold increase), respectively. Furthermore, the developed polymer HTMs can also significantly enhance the photovoltaic and photodetection performance of perovskite devices from 15.1% to 22.7% and from 2.7 x 10(12) to 2.17 x 10(13)Jones with the same device structure, indicating their great application potential in the emerging optoelectronics.
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| 48. |
- Liu, Yaoqian, et al.
(författare)
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Adjusting the rheological properties of corn-straw slurry to reduce the agitation power consumption in anaerobic digestion
- 2018
-
Ingår i: Bioresource Technology. - : Elsevier. - 0960-8524 .- 1873-2976. ; 272, s. 360-369
-
Tidskriftsartikel (refereegranskat)abstract
- Agitation power consumption (P) in the anaerobic digestion of biogas plants is a major consumer of electric energy. To reduce P by adjusting the rheological properties, in this work, the rheological properties of the corn-straw slurry were studied systematically considering the effects of TS, temperature and particle-size, and P was calculated based on the rheological behavior of the corn-straw slurry. The investigation shows that the corn-straw slurry is a non-Newtonian fluid and exhibit shear-thinning behavior, and the rheological properties can be well described with the power law model. The size-reduction is more effective compared to the option of temperature-increase to improve the agitation power efficiency, and the value of P can be reduced by up to 48.11 %. Since the size-reduction can also increase the methane yield, the reduction of the particle-size is a promising option to save P, especially at relatively high TSs and for the thermophilic AD process.
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| 49. |
- Liu, Yaoqian, et al.
(författare)
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Reducing the agitation power consumption in anaerobic digestion of corn straw by adjusting the rheological properties
- 2019
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Ingår i: Energy Procedia. - : Elsevier. - 1876-6102. ; 158, s. 1267-1272
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Tidskriftsartikel (refereegranskat)abstract
- Agitation power consumption (P) in the anaerobic digestion of biogas plants is a major part of the electric energy consumption. To reduce P by adjusting the rheological properties, in this work, the rheological properties of corn straw slurry were studied systematically with the consideration of the effects of TS, temperature and particle sizes. The P was calculated based on the rheological behaviour of corn straw slurry. The investigation shows that the thermophilic digestion is effective only for the slurry with a relatively high TS. The size-reduction is more effective at higher TS compared to the option of increasing temperature in order to improve the agitation power efficiency, and the value of P can be reduced by up to 48.11 %. Since the size-reduction can also increase the methane yield, the adjustment of particle sizes is a promising option to save P, especially at higher TS.
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- Lou, Xinyuan, et al.
(författare)
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A study on human perception in aircraft cabins and its association with volatile organic compounds
- 2022
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Ingår i: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 219
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Tidskriftsartikel (refereegranskat)abstract
- More than 8 million people fly on commercial aircraft each day with approximately 5% having a pre-existing respiratory disease. Thus it is necessary to provide high air quality in aircraft to protect public health. Volatile organic compounds (VOCs) present in aircraft cabins are suspected to contribute to the reported complaints. We investigated concentrations of VOCs, air temperature, relative humidity, and CO2 concentrations in a total of 46 flights, including 26 Chinese domestic flights and 20 international flights. We focused on the data from the cruising phase without meal serving in which the air supply and air recirculation were steady. A total of 284 passengers (i.e., 101 on international flights and 183 on Chinese domestic flights) were invited to participate in questionnaire surveys in this phase. We performed a linear mixed model analysis by controlling for potential confounders (age, gender, smoke habits, and history of allergy) to study associations between VOCs exposures and passengers' complaints. Xylene was significantly associated with irritations of the eyes, nose, and throat on both international and domestic flights, with antilog beta values from 1.12 to 1.28 (p < 0.05). The association of some aldehydes (i.e., nonanal, decanal, and heptanal), which are potential oxidation products with ozone, with passengers' sensory irritations was also significant, especially during international flights (antilog beta values: 1.19-1.22). It indicates that VOCs, especially xylene and aldehydes, in aircraft cabins may influence the perceived indoor air quality and complaints among passengers.
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