| 1. |
- 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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| 2. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Wang, Fang, et al.
(författare)
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Effects of the windshield inclination angle on head/brain injuries in car-to-pedestrian collisions using computational biomechanics models
- 2024
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Ingår i: Transportation Safety and Environment. - : Oxford University Press (OUP). - 2631-4428. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- Car-to-pedestrian collision (CPC) accidents occur frequently, and pedestrians often suffer serious head/brain injuries. One major cause is the primary impact with the windshield. Here, we use a numerical simulation method to study the influence of the windshield inclination angle of a passenger car on pedestrian head/brain injury due to CPC accidents. The range of the windshield inclination angle was set at 24 degrees-50 degrees, with an interval of 2 degrees. The results show that the windshield angle significantly affects the pedestrian kinematics and exerts different effects on the head injury when evaluating with various head injury criteria. Regarding the head peak linear/rotational acceleration and acceleration-based head injury criterion (HIC)/rotational injury criterion (RIC), the predictions at the secondary impact stage have no clear relationship with the windshield angle (R2=0.04, 0.07, 0.03 and 0.26, respectively) and their distributions are scattered. In the primary impact, the peak linear acceleration and HIC show a weak trend of first decreasing and then increasing with the increasing of the windshield angle, and the rotational acceleration and RIC tend to remain relatively constant. Regarding the cumulative strain damage measure (CSDM) criterion, the predictions at the primary impact are slightly lower than those at the secondary impact, and the trend of first decreasing and then increasing with the increase in the windshield angle is observed at both impact stages. When the windshield inclination angle is approximately 32 degrees-40 degrees, the head injury severity in both impact phases is generally lower than that predicted at other windshield angles.
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| 4. |
- Jin, Tingting, et al.
(författare)
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Efficient heterogeneous integration of InP/Si and GaSb/Si templates with ultra-smooth surfaces
- 2022
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Ingår i: Science China Information Sciences. - : Springer Science and Business Media LLC. - 1869-1919 .- 1674-733X. ; 65:8
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Tidskriftsartikel (refereegranskat)abstract
- Heterogeneous integration of InP and GaSb on Si substrates holds a huge potential interest in near-infrared and mid-infrared optoelectronic devices. In this study, 2-inch 180-nm-thick InP and 185-nm-thick GaSb thin layers were successfully transferred onto the Si substrates to form high-quality and ultra-smooth InP/Si and GaSb/Si templates using molecular beam epitaxy (MBE) and the ion-slicing technique together with selective chemical etching. The relocation of the implantation-introduced damage in the sacrificial layer enables the transfer of relatively defect-free InP and GaSb thin films. The sacrificial layers were completely etched off by selective chemical etching, leaving ultra-smooth epitaxial surfaces with a roughness of 0.2 nm for the InP/Si template and 0.9 nm for the GaSb/Si template, respectively. Thus, the chemical mechanical polishing (CMP) process was not required to smooth the surface which usually introduces particles and chemical contaminations on the transferred templates. Furthermore, the donor substrate is not consumed and can be recycled to reduce the cost, which provides a paradigm for the sustainable and economic development of the Si integration platform.
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| 5. |
- Li, Yong, et al.
(författare)
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Insight into jet-regeneration composite cooling technology employed in scramjet : Significance of relative positions of two jet holes
- 2024
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Ingår i: International Journal of Heat and Mass Transfer. - 0017-9310. ; 219
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Tidskriftsartikel (refereegranskat)abstract
- Due to the further increase in hypersonic vehicle speed, the scramjet faces supersonic combustion and aerodynamic heating, and the conventional single cooling method like regenerative cooling has been unable to meet the heat dissipation requirements of scramjet. The composite cooling system has become the hotspot of recent research. Jet cooling has a good cooling effect at high heat flux, so the jet-regeneration composite cooling method is innovatively proposed in this study. Compared with other composite cooling systems, the jet impingement can effectively weaken thermal boundary layer thickness. Initially, the total performance of the jet-regeneration composite cooling was experimentally verified via subcritical air. Furthermore, the numerical simulation of the jet-regeneration composite cooling was also carried out after the validation of turbulence models and mesh independence. Further examples, such as the jet impingement under the effect of the initial mainstream (so-called jet-mainstream) and regenerative cooling (so-called mainstream-only), are used to illustrate the advantages of this composite cooling (so-called jet-only). The heat transfer coefficient of jet-only is 2.6 times larger than that in the case of jet-mainstream. Compared with traditional regenerative cooling, even under the influence of the mainstream, the boundary layer thickness at the stagnation point of the jet impingement can be reduced by 40 times. This work is beneficial to the design of the jet-regeneration composite cooling system.
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| 6. |
- Liang, Hao, et al.
(författare)
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InAs/GaAs quantum dot laser epitaxially grown on on-axis (001) GaAsOI substrate
- 2021
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Ingår i: Optics Express. - 1094-4087 .- 1094-4087. ; 29:23, s. 38465-38476
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Tidskriftsartikel (refereegranskat)abstract
- Quantum dot (QD) laser as a light source for silicon optical integration has attracted great research attention because of the strategic vision of optical interconnection. In this paper, the communication band InAs QD ridge waveguide lasers were fabricated on GaAs-on-insulator (GaAsOI) substrate by combining ion-slicing technique and molecular beam epitaxy (MBE) growth. On the foundation of optimizing surface treatment processes, the InAs/In0.13Ga0.87As/GaAs dot-in-well (DWELL) lasers monolithically grown on a GaAsOI substrate were realized under pulsed operation at 20 °C. The static device measurements reveal comparable performance in terms of threshold current density, slope efficiency and output power between the QD lasers on GaAsOI and GaAs substrates. This work shows great potential to fabricate highly integrated light source on Si for photonic integrated circuits.
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| 7. |
- Lin, Jiajie, et al.
(författare)
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Wafer-scale heterogeneous integration InP on trenched Si with a bubble-free interface
- 2020
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Ingår i: APL Materials. - : AIP Publishing. - 2166-532X. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- Heterogeneous integration of compound semiconductors on a Si platform leads to advanced device applications in the field of Si photonics and high frequency electronics. However, the unavoidable bubbles formed at the bonding interface are detrimental for achieving a high yield of dissimilar semiconductor integration by the direct wafer bonding technology. In this work, lateral outgassing surface trenches (LOTs) are introduced to efficiently inhibit the bubbles. It is found that the chemical reactions in InP-Si bonding are similar to those in Si-Si bonding, and the generated gas can escape via the LOTs. The outgassing efficiency is dominated by LOTs' spacing, and moreover, the relationship between bubble formation and the LOT's structure is well described by a thermodynamic model. With the method explored in this work, a 2-in. bubble-free crystalline InP thin film integrated on the Si substrate with LOTs is obtained by the ion-slicing and wafer bonding technology. The quantum well active region grown on this Si-based InP film shows a superior photoemission efficiency, and it is found to be 65% as compared to its bulk counterpart.
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