| 31. |
- Qian, Xukun, et al.
(författare)
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Structure stability of metal-organic framework MIL-53 (Al) in aqueous solutions
- 2013
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 38:36, s. 16710-16715
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Tidskriftsartikel (refereegranskat)abstract
- The structural stability of MIL-53 (Al) in different pH aqueous solutions from room temperature to 100 degrees C has been investigated. Experimental results show MIL-53 (Al) is stable and highly resistant to hydrolysis in neutral and acidic solutions. It can retain its crystallinity and permanent porosity without structural collapse. The good structure stability of MIL-53 (Al) to aqueous solutions is quite unusual among the MOFs. The nitrogen adsorption for the soaked frameworks show a typical type I isotherm. In basic aqueous solution, MIL-53 (Al) undergoes structure transformation.
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| 32. |
- Quinlan, Ronald A., et al.
(författare)
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Transfer of carbon nanosheet films to nongrowth, zero thermal budget substrates
- 2011
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Ingår i: Journal of Vacuum Science & Technology B. - : American Vacuum Society. - 1071-1023 .- 1520-8567. ; 29:3, s. 030602-
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Tidskriftsartikel (refereegranskat)abstract
- Carbon-based nanostructures and materials have become a popular subject of research due to their unique thermal, mechanical, electrical, and optical properties. For example, the strong C-C bonds of graphene-based systems allow for excellent thermal conduction at room temperature and the conjugation of the sp(2) lattice enables extremely high electron mobility. However, the use of carbon nanostructures as a component in polymer composites, sensors, mirco-electro-mechanical systems, and both rigid and flexible electronics has been limited by several factors, including the incompatibility with standard photolithography techniques, the high temperatures required for the nanostructure growth, and the presence of-or complication-of removing noncarbon species. Here, the authors report on a novel method for the transfer of carbon nanosheets to a low or zero thermal budget substrate while maintaining their original morphology and electrical properties. Four-point probe measurements' post-transfer shows the retention of in-plane conductivity and scanning electron microscopy reveals the preservation of the original vertical morphology. Raman spectroscopy measurements confirm the retention of the graphitic structure of the post-transfer nanosheet film. This new transfer technique builds on the ability to conformally coat nanosheets while maintaining the original ultrahigh surface area morphology and the ability to fully incorporate nanosheets into several polymers while maintaining the original nanostructure separation. For a demonstration of the usefulness of polymer filling, carbon nanosheets were used as an ultrahigh surface area electrode for the photoactive polymer poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] in proof of principle experiments of a nanosheet-based organic photovoltaic device.
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| 33. |
- Sampson, Joshua N., et al.
(författare)
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Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for 13 Cancer Types
- 2015
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 0027-8874 .- 1460-2105. ; 107:12
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites. Methods: Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers. Results: GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, h(l)(2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (rho = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (rho = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (rho = 0.51, SE = 0.18), and bladder and lung (rho = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures. Conclusion: Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.
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| 34. |
- Sandels, Claes, et al.
(författare)
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Analyzing fundamental aggregation functions in power systems
- 2011
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Ingår i: IEEE PES Innovative. Smart Grid Technol. Conf. Europe. - : IEEE. - 9781457714214
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Konferensbidrag (refereegranskat)abstract
- The concept of Aggregators is receiving large attention when new business cases for Smart grids are presented. Several studies propose different schemes of aggregating load and/or production. However, many of these studies are tailored for one specific market or network, making the generic value of the work small. The objective of the work presented in the paper is to analyze the fundamental needs for aggregating small scale loads or production units from a technical, financial and regulatory point of view. The final results of the analysis can work as a foundation for developing more elaborate aggregation business cases. These can later be analyzed from a technical and economical standpoint by, e.g., simulations.
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| 35. |
- Tian, Yu, et al.
(författare)
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Revealing morphology rules of MX precipitates in Ti-V-Nb multi-microalloyed steels
- 2022
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Ingår i: Materials Characterization. - : Elsevier BV. - 1044-5803 .- 1873-4189. ; 188
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Tidskriftsartikel (refereegranskat)abstract
- Despite a large number of studies relevant to MX (M = Ti, V, Nb; X = C, N) precipitation in microalloyed steels, the evolution rules of the precipitate morphology remain unclear. In this work, the precipitation behavior and morphological characteristics of MX precipitates in deformed Ti-V-Nb multi-microalloyed steels under contin-uous cooling were revealed through integrating transmission electron microscopy and theoretical models. The experimental results demonstrate that the precipitates are mainly Ti-rich cuboidal multi-component precipitates and irregular compound precipitates formed in austenite, and fine spherical V8C7 precipitates formed in ferrite. For the first time, the L parameter model that evaluates the shape of MX precipitates has been introduced into microalloyed steels, together with the validating experiments. In austenite, as the L increases, precipitates tend to become cuboidal under equilibrium conditions while rod-like elongating along their (100) orientation under deformation conditions; in ferrite, as the L increases, precipitates tend to be disk-like under equilibrium con-ditions while thin elliptical cylindrical extending along their (110) orientation on the habit plane under defor-mation conditions. The evolution rules of precipitate morphology revealed in this work provide insights in controlling precipitates morphology to develop high-performance microalloyed steels.
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| 36. |
- Wang, Yu, et al.
(författare)
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FlexZNS : Building High-Performance ZNS SSDs with Size-Flexible and Parity-Protected Zones
- 2023
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Ingår i: Proceedings - 2023 IEEE 41st International Conference on Computer Design, ICCD 2023. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 291-299
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Konferensbidrag (refereegranskat)abstract
- NVMe zoned namespace (ZNS) SSDs present a new class of storage devices with attractive features including low cost, software definability, and stable performance. However, one primary culprit that hinders the adoption of ZNS is the high garbage collection (GC) overhead it brings to host software. The ZNS interface divides the logical address space into size-fixed zones that must be written sequentially. Despite being friendly to flash memory, ZNS requires host software to perform out-of-place updates and GC on individual zones. Current ZNS SSDs typically employ a large zone size (e.g., of GBs) to be conducive to die-level RAID protection on flash memory. This impedes flexible data placement, such as mixing data with different lifetimes in the same zone, and incurs sizable data migrations during zone GC. To address this problem, we propose FlexZNS, a novel ZNS SSD design that provides reliable zoned storage allowing host software to configure the zone size flexibly as well as multiple zone sizes. The size variability of zones poses two interrelated challenges, one for the SSD controller to establish per-zone RAID protection, and the other for host software to manage variable zone capacity loss caused by parity storage. To tackle the challenges, FlexZNS decouples the storage of parity from individual zones on flash memory and hides the zone capacity loss from the host software. We verify FlexZNS on a ZNS-compatible file system F2FS and a popular key-value store RocksDB. Extensive experiments demonstrate that FlexZNS can significantly improve the system performance and reduce GC-induced write amplification, compared with a conventional ZNS SSD with large-sized zones.
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| 37. |
- Woo, Jong Hun, et al.
(författare)
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Assessment Framework of Smart Shipyard Maturity Level via Data Envelopment Analysis
- 2021
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 13:4
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Tidskriftsartikel (refereegranskat)abstract
- The fourth industrial revolution ("Industry 4.0") has caused an escalating need for smart technologies in manufacturing industries. Companies are examining various cutting-edge technologies to realize smart manufacturing and construct smart factories and are devoting efforts to improve their maturity level. However, productivity improvement is rarely achieved because of the large variety of new technologies and their wide range of applications; thus, elaborately setting improvement goals and plans are seldom accomplished. Fortunately, many researchers have presented guidelines for diagnosing the smartness maturity level and systematic directions to improve it, for the eventual improvement of productivity. However, most research has focused on mass production industries wherein the overall smartness maturity level is already high (e.g., high-level automation). These studies thus have limited applicability to the shipbuilding industry, which is basically a built-to-order industry. In this study, through a technical demand survey of the shipbuilding industry and an investigation of existing smart manufacturing and smart factories, the keywords of connectivity, automation, and intelligence were derived and based on these keywords, we developed a new diagnostic framework for smart shipyard maturity level assessment. The framework was applied to eight shipyards in South Korea to diagnose their smartness maturity level, and a data envelopment analysis (DEA) was performed to confirm the usefulness of the diagnosis results. By comparing the DEA models, the results with the smart level as an input represents the actual efficiency of shipyards better than the results of conventional models.
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| 38. |
- Wu, Renbing, et al.
(författare)
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Pt nanodendrites anchored on bamboo-shaped carbon nanofiber arrays as highly efficient electrocatalyst for oxygen reduction reaction
- 2013
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 38:36, s. 16677-16684
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Tidskriftsartikel (refereegranskat)abstract
- In order to improve the Pt utilization and enhance their catalytic performance in fuel cells, a novel composite electrode composed of single-crystalline Pt nanodendrites and support constructed by bamboo-shaped carbon nanofiber arrays (CNFAs) on carbon paper, is reported. This electrode is designed by growing vertically CNFAs on carbon paper via plasma enhanced chemical vapor deposition, followed by the direct synthesis of Pt nanodendrites using a simple surfactant-free aqueous solution method. Electron microscopy studies reveal that the Pt nanodendrites are uniformly high dispersed and anchored on the surface of CNFAs. Electrochemical measurements demonstrate that the resultant electrode exhibits higher electrocatalytic activity and stability for oxygen reduction reaction than commercial Pt/C catalyst, suggesting its potential application in fuel cells.
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| 39. |
- Wu, Yiming, 1987-, et al.
(författare)
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Framework incorporating synchronized phasor data for power system operation and control
- 2012
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Ingår i: The 9th IET International Conference on Advances in Power System Control, Operation and Management. - : Institution of Engineering and Technology. - 9781849197434
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Konferensbidrag (refereegranskat)abstract
- This position paper presents initial research and investigation on a unified framework combining two independent systems, the legacy SCADA system and the synchronized phasor data system, that share the same measurement sources, i.e., current and voltage transducers and the same communication medium. In this framework, conventional SCADA system coupled with substation automation system are modeled together with synchronized phasor systems. The contribution of this paper also includes a state-of–the-art survey of topics related to the proposed architectures. Furthermore, an overview of the data flows between substation and control centers including both SCADA and phasor measurements are presented. Taking into consideration the growing interest in communication and automation standardization this paper also addresses the communication between the substations coupled with relevant standards and technology.
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| 40. |
- Wu, Yiming, 1987-, et al.
(författare)
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Perspectives on Peer-to-Peer Data Delivery Architectures for Next Generation Power Systems
- 2013
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Ingår i: Smart Grid Management.
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Konferensbidrag (refereegranskat)abstract
- Introduction of new Information and Communication Technologies (ICT) and aggregation of equipment bring in new perspectives in terms of the increasing number of data users. It also brings new data delivery requirements which are difficult to be met by the legacy systems. Off-the-shelf standards and communication technologies are the enablers to push current data delivery solutions to a new level. At this level this new data delivery system can fulfill Quality of Service (QoS) requirements of next generation power system. This paper proposes a comprehensive architecture of Peer-to-Peer (P2P) based overlay-control data delivery system covering all levels of data delivery. The core technology of such an architecture lays on the Intelligent Substation Gateway (ISG), which is employed to provide data delivery service to meet the QoS requirements. Proposed data delivery system brings advantages as autonomy, flexibility, scalability, and efficient to the power system.
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