Search

Your search keyword '"Trinh C"' showing total 184 results
Start Over Author "Trinh C"
184 results on '"Trinh C"'

1. Priority and Traffic-Aware Contention-Based Medium Access Control Scheme for Multievent Wireless Sensor Networks

Author

Trinh C. Nguyen, Hai-Chau Le, Sohail Sarang, Micheal Drieberg, and Thu-Hang T. Nguyen

Subjects
Contention window, the Internet of Things, medium access control, multi-event wireless sensor networks, quality of service, Electrical engineering. Electronics. Nuclear engineering, TK1-9971
Abstract

The requirement of high quality of service (QoS) in multi-priority industrial and domestic sensor networks poses new challenges to the increasing adoption of Internet of Things (IoT). In Multi-event Wireless Sensor Networks (MWSNs), nodes generate different types of data packets i.e., urgent (high priority) or normal (low priority), with different traffic proportions. High priority packets require an assurance of faster transmission and higher reliability in the network. In the literature, the existing medium access control (MAC) protocols for MWSNs have limited consideration in supporting data priority with different traffic proportions. Therefore, this paper proposes an energy efficient MAC scheme that incorporates multi-priority of data packets with dynamic traffic proportion, called PriTraCon-MAC. PriTraCon-MAC supports multi-events by considering four different priority levels of data packets and uses a novel approach that adjusts the contention window adaptively. Due to that, Request-To-Send frame of higher priority data can be sent earlier in the contention window, resulting in the corresponding faster acceptance by the receiver. Furthermore, mathematical delay analysis with different priority traffic proportions has also been undertaken. In addition, PriTraCon-MAC has been implemented in OMNET++ Castalia and its performance has been evaluated in terms of packet delay, reliability, and energy consumption, and compared with the existing Timeout Multi-priority based-MAC (TMPQ-MAC) under various network conditions. The simulation results demonstrate that PriTraCon-MAC offers lower average delay and achieves significantly higher packet success rate, while reducing energy consumption by up to 80% when compared with TMPQ-MAC protocol.

Published
2022
Full Text
View/download PDF

2. Imaging of bandtail states in silicon heterojunction solar cells

Author

Teferi, M. Y., Malissa, H., Morales-Vilches, A. B., Trinh, C. T., Korte, L., Stannowski, B., Williams, C. C., Boehme, C., and Lips, K.

Subjects
Physics - Applied Physics, Condensed Matter - Materials Science
Abstract

Silicon heterojunction (SHJ) solar cells represent a promising technological approach towards higher photovoltaics efficiencies and lower fabrication cost. While the device physics of SHJ solar cells have been studied extensively in the past, the ways in which nanoscopic electronic processes such as charge-carrier generation, recombination, trapping, and percolation affect SHJ device properties macroscopically have yet to be fully understood. We report the study of atomic scale current percolation at state-of-the-art a-Si:H/c-Si heterojunction solar cells under ambient operating conditions, revealing the profound complexity of electronic SHJ interface processes. Using conduction atomic force microscopy (cAFM), it is shown that the macroscopic current-voltage characteristics of SHJ solar cells is governed by the average of local nanometer-sized percolation pathways associated with bandtail states of the doped a-Si:H selective contact leading to above bandgap open circuit voltages ($V_{\mbox{OC}}$) as high as 1.2 V ($V_{\mbox{OC}}>e E_{\mbox{gap}}^{\mbox{Si}}$). This is not in violation of photovoltaic device physics but a consequence of the nature of nanometer-scale charge percolation pathways which originate from trap-assisted tunneling causing dark leakage current. We show that the broad distribution of local photovoltage is a direct consequence of randomly trapped charges at a-Si:H dangling bond defects which lead to strong local potential fluctuations and induce random telegraph noise of the dark current., Comment: Manuscript: 27 pages, 3 figures; Supplementary Information: 19 pages, 9 figures

Published
2020
Full Text
View/download PDF

3. Silicon heterojunction solar cells explored via noise spectroscopy: spatial selectivity and the influence of a-Si passivating layers

Author

Davenport, Kevin, Hayward, Mark, Trinh, C. T., Lips, Klaus, and Rogachev, Andrey

Subjects
Physics - Applied Physics, Condensed Matter - Materials Science
Abstract

We have employed state-of-the-art cross-correlation noise spectroscopy to study carrier dynamics in silicon heterojunction solar cells, complimented by SENTARUS simulations of the same devices. These cells were composed of a light absorbing n-doped crystalline silicon layer contacted by passivating layers of i-a-Si:H and doped a-Si:H electrode layers. The method provided a two-orders-of-magnitude improved sensitivity and allowed to resolution of three additional contributions to noise in addition to 1/f noise. We have observed shot noise with Fano factor close to unity. We have also observed a peculiar generation-recombination term, which presents only under light illumination with energy above 2 eV and thus reflects light absorption and carrier trapping in the a-Si:H layers. A second, low-frequency generation-recombination term was detected at temperatures below 100 K. We argue that it appears because the process of charge carrier transfer across i-a-Si:H occurs via an intermediate defect limited by tunneling above about 100 K and a thermally assisted process below this temperature. We also discuss the spatial selectivity of noise spectroscopy, namely the tendency of the method to amplify noise contributions from the most resistive element of the cell. Indeed, in our case, all three terms are linked to the passivating i-a-Si:H layer., Comment: 11 pages, 7 figures

Published
2020

4. SOFIA/HAWC+ traces the magnetic fields in NGC 1068

Author

Lopez-Rodriguez, E., Dowell, C. D., Jones, T. J., Harper, D. A., Berthoud, M., Chuss, D., Dale, D. A., Guerra, J. A., Hamilton, R. T., Looney, L. W., Michail, J. M., Nikutta, R., Novak, G., Santos, F. P., Sheth, K., Siah, J., Staguhn, J., Stephens, I. W., Tassis, K., Trinh, C. Q., Ward-Thompson, D., Werner, M., Wollack, E. J., and Zweibel, E.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We report the first detection of galactic spiral structure by means of thermal emission from magnetically aligned dust grains. Our 89 $\mu$m polarimetric imaging of NGC 1068 with the High-resolution Airborne Wideband Camera/Polarimeter (HAWC+) on NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) also sheds light on magnetic field structure in the vicinity of the galaxy's inner-bar and active galactic nucleus (AGN). We find correlations between the 89 $\mu$m magnetic field vectors and other tracers of spiral arms, and a symmetric polarization pattern as a function of the azimuthal angle arising from the projection and inclination of the disk field component in the plane of the sky. The observations can be fit with a logarithmic spiral model with pitch angle of $16.9^{+2.7}_{-2.8}$$^{\circ}$ and a disk inclination of $48\pm2^{\circ}$. We infer that the bulk of the interstellar medium from which the polarized dust emission originates is threaded by a magnetic field that closely follows the spiral arms. Inside the central starburst disk ($<1.6$ kpc), the degree of polarization is found to be lower than for far-infrared sources in the Milky Way, and has minima at the locations of most intense star formation near the outer ends of the inner-bar. Inside the starburst ring, the field direction deviates from the model, becoming more radial along the leading edges of the inner-bar. The polarized flux and dust temperature peak $\sim 3-6$" NE of the AGN at the location of a bow shock between the AGN outflow and the surrounding interstellar medium, but the AGN itself is weakly polarized ($< 1$%) at both 53 and 89 \um., Comment: 13 pages, 7 figures, Accepted for publication by ApJ

Published
2019
Full Text
View/download PDF

5. The PROSPECT Reactor Antineutrino Experiment

Author

PROSPECT Collaboration, Ashenfelter, J., Balantekin, A. B., Baldenegro, C., Band, H. R., Bass, C. D., Bergeron, D. E., Berish, D., Bignell, L. J., Bowden, N. S., Boyle, J., Bricco, J., Brodsky, J. P., Bryan, C. D., Telles, A. Bykadorova, Cherwinka, J. J., Classen, T., Commeford, K., Conant, A., Cox, A. A., Davee, D., Dean, D., Deichert, G., Diwan, M. V., Dolinski, M. J., Erickson, A., Foust, B. T., Gaison, J. K., Galindo-Uribarri, A., Gilbert, C., Gilje, K., Glenn, A., Goddard, B. W., Hackett, B., Han, K., Hans, S., Hansell, A. B., Heeger, K. M., Heffron, B., Insler, J., Jaffe, D. E., Ji, X., Jones, D. C., Koehler, K., Kyzylova, O., Lane, C. E., Langford, T. J., LaRosa, J., Littlejohn, B. R., Lopez, F., Lu, X., Caicedo, D. A. Martinez, Matta, J. T., McKeown, R. D., Mendenhall, M. P., Miller, H. J., Minock, J., Mueller, P. E., Mumm, H. P., Napolitano, J., Neilson, R., Nikkel, J. A., Norcini, D., Nour, S., Pushin, D. A ., Qian, X., Romero-Romero, E., Rosero, R., Sarenac, D., Seilhan, B., Sharma, R., Surukuchi, P. T., Trinh, C., Tyra, M. A., Varner, R. L., Viren, B., Wagner, J. M., Wang, W., White, B., White, C., Wilhelmi, J., Wise, T., Yao, H., Yeh, M., Yen, Y. -R., Zhang, A., Zhang, C., Zhang, X., and Zhao, M.

Subjects
Physics - Instrumentation and Detectors
Abstract

The Precision Reactor Oscillation and Spectrum Experiment, PROSPECT, is designed to make both a precise measurement of the antineutrino spectrum from a highly-enriched uranium reactor and to probe eV-scale sterile neutrinos by searching for neutrino oscillations over meter-long baselines. PROSPECT utilizes a segmented $^6$Li-doped liquid scintillator detector for both efficient detection of reactor antineutrinos through the inverse beta decay reaction and excellent background discrimination. PROSPECT is a movable 4-ton antineutrino detector covering distances of 7m to 13m from the High Flux Isotope Reactor core. It will probe the best-fit point of the $\bar\nu_e$ disappearance experiments at 4$\sigma$ in 1 year and the favored regions of the sterile neutrino parameter space at more than 3$\sigma$ in 3 years. PROSPECT will test the origin of spectral deviations observed in recent $\theta_{13}$ experiments, search for sterile neutrinos, and address the hypothesis of sterile neutrinos as an explanation of the reactor anomaly. This paper describes the design, construction, and commissioning of PROSPECT and reports first data characterizing the performance of the PROSPECT antineutrino detector., Comment: 30 pages, 33 figures; updated with journal revision and reference

Published
2018
Full Text
View/download PDF

6. Dust Production Rates in the Fomalhaut Debris Disk from SOFIA/FORCAST Mid-infrared Imaging

Author

Adams, J. D., Herter, T. L., Lau, R. M., Trinh, C., and Hankins, M.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the first spatially resolved mid-infrared (37.1 $\mu$m) image of the Fomalhaut debris disk. We use PSF fitting and subtraction to distinctly measure the flux from the unresolved component and the debris disk. We measure an infrared excess in the point source of $0.9 \pm 0.2$ Jy, consistent with emission from warm dust in an inner disk structure (Su et al. 2016), and inconsistent with a stellar wind origin. We cannot confirm or rule out the presence of a pileup ring (Su et al. 2016) near the star. In the cold region, the 37 $\mu$m imaging is sensitive to emission from small, blowout grains, which is an excellent probe of the dust production rate from planetesimal collisions. Under the assumptions that the dust grains are icy aggregates and the debris disk is in steady state, this result is consistent with the dust production rates predicted by Kenyon & Bromley (2008) from theoretical models of icy planet formation. We find a dust luminosity of $(7.9 \pm 0.8) \times 10^{-4}$ L$_\odot$ and a dust mass of 8 -- 16 lunar masses, depending on grain porosity, with $\sim 1$ lunar mass in grains with radius 1 $\mu$m -- 1 mm. If the grains are icy and highly porous, meter-sized objects must be invoked to explain the far-IR, submm, and mm emission. If the grains are composed of astronomical silicates, there is a dearth of blowout grains (Pawellek et al. 2014) and the mass loss rate is well below the predicted dust production values., Comment: 8 pages, 8 figures, 2 tables, accepted for publication in ApJ

Published
2018
Full Text
View/download PDF

7. First search for short-baseline neutrino oscillations at HFIR with PROSPECT

Author

Ashenfelter, J., Balantekin, A. B., Baldenegro, C., Band, H. R., Bass, C. D., Bergeron, D. E., Berish, D., Bignell, L. J., Bowden, N. S., Bricco, J., Brodsky, J. P., Bryan, C. D., Telles, A. Bykadorova, Cherwinka, J. J., Classen, T., Commeford, K., Conant, A. J., Cox, A. A., Davee, D., Dean, D., Deichert, G., Diwan, M. V., Dolinski, M. J., Erickson, A., Febbraro, M., Foust, B. T., Gaison, J. K., Galindo-Uribarri, A., Gilbert, C. E., Gilje, K. E., Glenn, A., Goddard, B. W., Hackett, B. T., Han, K., Hans, S., Hansell, A. B., Heeger, K. M., Heffron, B., Insler, J., Jaffe, D. E., Ji, X., Jones, D., Koehler, K., Kyzylova, O., Lane, C. E., Langford, T. J., LaRosa, J., Littlejohn, B. R., Lopez, F., Lu, X., Caicedo, D. A. Martinez, Matta, J., McKeown, R. D., Mendenhall, M. P., Miller, H. J., Minock, J. M., Mueller, P. E., Mumm, H. P., Napolitano, J., Neilson, R., Nikkel, J. A., Norcini, D., Nour, S., Pushin, D. A., Qian, X., Romero-Romero, E., Rosero, R., Sarenac, D., Seilhan, B. S., Sharma, R., Surukuchi, P. T., Trinh, C., Tyra, M. A., Varner, R. L., Viren, B., Wagner, J. M., Wang, W., White, B., White, C., Wilhelmi, J., Wise, T., Yao, H., Yeh, M., Yen, Y. R., Zhang, A., Zhang, C., Zhang, X., and Zhao, M.

Subjects
High Energy Physics - Experiment
Abstract

This Letter reports the first scientific results from the observation of antineutrinos emitted by fission products of $^{235}$U at the High Flux Isotope Reactor. PROSPECT, the Precision Reactor Oscillation and Spectrum Experiment, consists of a segmented 4 ton $^6$Li-doped liquid scintillator detector covering a baseline range of 7-9 m from the reactor and operating under less than 1 meter water equivalent overburden. Data collected during 33 live-days of reactor operation at a nominal power of 85 MW yields a detection of 25461 $\pm$ 283 (stat.) inverse beta decays. Observation of reactor antineutrinos can be achieved in PROSPECT at 5$\sigma$ statistical significance within two hours of on-surface reactor-on data-taking. A reactor-model independent analysis of the inverse beta decay prompt energy spectrum as a function of baseline constrains significant portions of the previously allowed sterile neutrino oscillation parameter space at 95% confidence level and disfavors the best fit of the Reactor Antineutrino Anomaly at 2.2$\sigma$ confidence level., Comment: 7 pages, 5 figures; v3: Added additional supplemental files

Published
2018
Full Text
View/download PDF

8. Performance of a segmented $^{6}$Li-loaded liquid scintillator detector for the PROSPECT experiment

Author

Ashenfelter, J., Balantekin, A. B., Band, H. R., Bass, C. D., Bergeron, D. E., Berish, D., Bowden, N. S., Brodsky, J. P., Bryan, C. D., Telles, A. Bykadorova, Cherwinka, J. J., Classen, T., Commeford, K., Conant, A., Davee, D., Deichert, G., Diwan, M. V., Dolinski, M. J., Erickson, A., Foust, B. T., Gaison, J. K., Galindo-Uribarri, A., Gilje, K., Hackett, B., Han, K., Hans, S., Hansell, A., Heeger, K. M., Heffron, B., Insler, J., Jaffe, D. E., Jones, D., Kyzylova, O., Lane, C. E., Langford, T. J., LaRosa, J., Littlejohn, B. R., Lopez, F., Caicedo, D. A. Martinez, Matta, J., McKeown, R. D., Mendenhall, M. P., Minock, J., Mueller, P. E., Mumm, H. P., Napolitano, J., Neilson, R., Nikkel, J. A., Norcini, D., Nour, S., Pushin, D. A., Qian, X., Romero-Romero, E., Rosero, R., Surukuchi, P. T., Trinh, C., Tyra, M. A., Wagner, J. M., White, C., Wilhelmi, J., Wise, T., Yeh, M., Yen, Y. -R., Zhang, A., Zhang, C., and Zhang, X.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

This paper describes the design and performance of a 50 liter, two-segment $^{6}$Li-loaded liquid scintillator detector that was designed and operated as prototype for the PROSPECT (Precision Reactor Oscillation and Spectrum) Experiment. The two-segment detector was constructed according to the design specifications of the experiment. It features low-mass optical separators, an integrated source and optical calibration system, and materials that are compatible with the $^{6}$Li-doped scintillator developed by PROSPECT. We demonstrate a high light collection of 850$\pm$20 PE/MeV, an energy resolution of $\sigma$ = 4.0$\pm$0.2% at 1 MeV, and efficient pulse-shape discrimination of low $dE/dx$ (electronic recoil) and high $dE/dx$ (nuclear recoil) energy depositions. An effective scintillation attenuation length of 85$\pm$3 cm is measured in each segment. The 0.1% by mass concentration of $^{6}$Li in the scintillator results in a measured neutron capture time of $\tau$ = 42.8$\pm$0.2 $\mu s$. The long-term stability of the scintillator is also discussed. The detector response meets the criteria necessary for achieving the PROSPECT physics goals and demonstrates features that may find application in fast neutron detection., Comment: 16 pages, 13 figures; minor edits to design detail and references

Published
2018
Full Text
View/download PDF

9. An Overview of Immune Checkpoints and Immunotherapy in Cancer

Author

Huynh, T. Q., Tran, D. N., Chau, T. P., Huynh, T. M., Trinh, C. H., Doan, N., Magjarevic, Ratko, Series Editor, Ładyżyński, Piotr, Associate Editor, Ibrahim, Fatimah, Associate Editor, Lackovic, Igor, Associate Editor, Rock, Emilio Sacristan, Associate Editor, Van Toi, Vo, editor, Le, Trung Quoc, editor, Ngo, Hoan Thanh, editor, and Nguyen, Thi-Hiep, editor

Published
2020
Full Text
View/download PDF

11. Suppression of the near-infrared OH night sky lines with fibre Bragg gratings - first results

Author

Ellis, S. C., Bland-Hawthorn, J., Lawrence, J., Horton, A. J., Trinh, C., Leon-Saval, S. G., Shortridge, K., Bryant, J., Case, S., Colless, M., Couch, W., Freeman, K., Gers, L., Glazebrook, K., Haynes, R., Lee, S., Loehmannsroeben, H. -G., Byrne, J. O., Miziarski, S., Roth, M., Schmidt, B., Tinney, C. G., and Zheng, J.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The background noise between 1 and 1.8 microns in ground-based instruments is dominated by atmospheric emission from hydroxyl molecules. We have built and commissioned a new instrument, GNOSIS, which suppresses 103 OH doublets between 1.47 - 1.7 microns by a factor of ~1000 with a resolving power of ~10,000. We present the first results from the commissioning of GNOSIS using the IRIS2 spectrograph at the AAT. The combined throughput of the GNOSIS fore-optics, grating unit and relay optics is ~36 per cent, but this could be improved to ~46 per cent with a more optimal design. We measure strong suppression of the OH lines, confirming that OH suppression with fibre Bragg gratings will be a powerful technology for low resolution spectroscopy. The integrated OH suppressed background between 1.5 and 1.7 microns is reduced by a factor of 9 compared to a control spectrum using the same system without suppression. The potential of low resolution OH suppressed spectroscopy is illustrated with example observations. The GNOSIS background is dominated by detector dark current below 1.67 microns and by thermal emission above 1.67 microns. After subtracting these we detect an unidentified residual interline component of ~ 860 +/ 210 ph/s/m^2/micron/arcsec^2. This component is equally bright in the suppressed and control spectra. We have investigated the possible source of the interline component, but were unable to discriminate between a possible instrumental artifact and intrinsic atmospheric emission. Resolving the source of this emission is crucial for the design of fully optimised OH suppression spectrographs. The next generation OH suppression spectrograph will be focussed on resolving the source of the interline component, taking advantage of better optimisation for a FBG feed. We quantify the necessary improvements for an optimal OH suppressing fibre spectrograph design., Comment: Accepted for publication in MNRAS. 15 pages, 18 figures

Published
2012
Full Text
View/download PDF

12. A complex multi-notch astronomical filter to suppress the bright infrared sky

Author

Bland-Hawthorn, J., Ellis, S. C., Leon-Saval, S. G., Haynes, R., Roth, M. M., Löhmannsröben, H. -G., Horton, A. J., Cuby, J. -G., Birks, T. A., Lawrence, J. S., Gillingham, P., Ryder, S. D., and Trinh, C.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

A long-standing and profound problem in astronomy is the difficulty in obtaining deep near-infrared observations due to the extreme brightness and variability of the night sky at these wavelengths. A solution to this problem is crucial if we are to obtain the deepest possible observations of the early Universe since redshifted starlight from distant galaxies appears at these wavelengths. The atmospheric emission between 1000 nm and 1800 nm arises almost entirely from a forest of extremely bright, very narrow hydroxyl emission lines that varies on timescales of minutes. The astronomical community has long envisaged the prospect of selectively removing these lines, while retaining high throughput between the lines. Here we demonstrate such a filter for the first time, presenting results from the first on-sky tests. Its use on current 8m telescopes and future 30m telescopes will open up many new research avenues in the years to come., Comment: 15 pages, 5 figures. Nature Communications. Published 06 December 2011

Published
2011
Full Text
View/download PDF

15. Numerical study on a facing electrode configuration dielectrophoresis microfluidic system for efficient biological cell separation

Author

Thu Hang Nguyen, Hoang Trung Nguyen, Nam Anh Ngo, Mai Chi Nguyen, Hang Bui Thu, Jens Ducrée, Trinh Chu Duc, Thanh Tung Bui, and Loc Do Quang

Subjects
Dielectrophoresis, Microfluidic chip, Cell separation, Cancer cell analysis, Medicine, Science
Abstract

Abstract Circulating tumor cell separation has been the focus of numerous studies owing to its importance in the diagnosis, prognosis, and therapy of cancer. This study reports a highly efficient microfluidic device that integrates a specialized dielectrophoresis configuration, namely the facing-electrode configuration dielectrophoresis (FEC-DEP) structure, to isolate circulating tumor cells (CTCs) from various blood components, including red blood cells, white blood cells, and platelets. The FEC-DEP design features a bottom-slanted electrode array positioned parallel to a basic rectangular top electrode. A non-homogeneous electric field is produced between these parallel electrodes, generating dielectrophoretic forces acting on cells. Consequently, when the FEC-DEP is integrated into a flow, it can direct various biological objects in the flow along separate trajectories. As a result, cells with comparable characteristics might move together within a similar path. This configuration may simplify the microfabrication process and lessen dependency on particle position within the microchannel. The separation process was numerically analyzed using the finite element method, and device parameters were optimized to obtain high-efficiency and high-purity cell separation. The simulations show that the microfluidic device may effectively enrich tumor cells in a label-free and non-invasive manner, with a high-efficiency rate of almost 80%.

Published
2024
Full Text
View/download PDF

16. LB1041 Machine learning-based single cell analysis of prurigo nodularis identifies a unique population of CD14+pERK+ macrophages correlating with itch intensity

Author

Patel, J., primary, Deng, J., additional, Parthasarathy, V., additional, Szeto, M., additional, Marani, M., additional, Trinh, C., additional, Lee, K., additional, Olapido, O., additional, Kwatra, M., additional, Kang, S., additional, Alphonse, M.P., additional, and Kwatra, S.G., additional

Published
2022
Full Text
View/download PDF

17. Detection of co-infection and recombination cases with Omicron and local Delta variants of SARS-CoV-2 in Vietnam

Author

Nguyen Thu Trang, Trinh Cong Dien, Nguyen Thi Tam, Phan Manh Cuong, Le Van Duyet, Nguyen Thi Hong Thuong, Van Dinh Trang, Pham Ngoc Thach, H. Rogier van Doorn, Thomas Kesteman, and OUCRU COVID-19 research group

Subjects
Medicine, Science
Abstract

Abstract The first nationwide outbreak of COVID-19 in Vietnam started in late April 2021 and was caused almost exclusively by a single Delta lineage, AY.57. In early 2022, multiple Omicron variants co-circulated with Delta variants and quickly became dominant. The co-circulation of Delta and Omicron happened leading to possibility of co-infection and recombination events which can be revealed by viral genomic data. From January to October 2022, a total of 1028 viral RNA samples out of 4852 positive samples (Ct

Published
2024
Full Text
View/download PDF

20. External auricle temperature enhances ear-based wearable accuracy during physiological strain monitoring in the heat

Author

Shawn Chee Chong Tan, Trinh Canh Khanh Tran, Charis Yi Ning Chiang, Jieming Pan, and Ivan Cherh Chiet Low

Subjects
Medicine, Science
Abstract

Abstract Body core temperature (Tc) monitoring is crucial for minimizing heat injury risk. However, validated strategies are invasive and expensive. Although promising, aural canal temperature (Tac) is susceptible to environmental influences. This study investigated whether incorporation of external auricle temperature (Tea) into an ear-based Tc algorithm enhances its accuracy during multiple heat stress conditions. Twenty males (mean ± SD; age = 25 ± 3 years, BMI = 21.7 ± 1.8, body fat = 12 ± 3%, maximal aerobic capacity (VO2max) = 64 ± 7 ml/kg/min) donned an ear-based wearable and performed a passive heating (PAH), running (RUN) and brisk walking trial (WALK). PAH comprised of immersion in hot water (42.0 ± 0.3 °C). RUN (70 ± 3%VO2max) and WALK (50 ± 10%VO2max) were conducted in an environmental chamber (Tdb = 30.0 ± 0.2 °C, RH = 71 ± 2%). Several Tc models, developed using Tac, Tea and heart rate, were validated against gastrointestinal temperature. Inclusion of Tea as a model input improved the accuracy of the ear-based Tc algorithm. Our best performing model (Trf3) displayed good group prediction errors (mean bias error = − 0.02 ± 0.26 °C) but exhibited individual prediction errors (percentage target attainment ± 0.40 °C = 88%) that marginally exceeded our validity criterion. Therefore, Trf3 demonstrates potential utility for group-based Tc monitoring, with additional refinement needed to extend its applicability to personalized heat strain monitoring.

Published
2024
Full Text
View/download PDF

22. COVID-19 patients hospitalized after the fourth wave of the pandemic period in Vietnam: Clinical, laboratory, therapeutic features, and clinical outcomes

Author

Trinh Cong Dien, Le Van Nam, Pham Ngoc Thach, and Le Van Duyet

Subjects
Sars-Cov-2, COVID-19, Severe, Variants, Complications, Medicine (General), R5-920
Abstract

Background/Purpose: Despite having relatively high COVID-19 vaccine coverage in Vietnam, a fraction of COVID-19 patients required hospitalization due to severe symptoms. The purpose of this study was to describe the clinical, laboratory, complications, and treatment of COVID-19 patients hospitalized during the pandemic's fourth wave. Methods: Genome sequencing was performed on COVID-19 patients. Data on clinical characteristics, treatment, complications, and outcomes were consistently collected. Results: The clinical classifications were mild (37.43%), moderate (24.2%), and severe (38.37%). Patients with co-morbidities, high fever >39 °C, hypertension, tachycardia, tachypnea, and SpO2

Published
2024
Full Text
View/download PDF

26. Directed Assembly of Homopentameric Cholera Toxin B-Subunit Proteins into Higher-Order Structures Using Coiled-Coil Appendages

Author

Ross J. F., Wildsmith G. C., Johnson M., Hurdiss D. L., Hollingsworth K., Thompson R. F., Mosayebi M., Trinh C. H., Paci E., Pearson A. R., Webb M. E., Turnbull W. B., Ross J.F., Wildsmith G.C., Johnson M., Hurdiss D.L., Hollingsworth K., Thompson R.F., Mosayebi M., Trinh C.H., Paci E., Pearson A.R., Webb M.E., and Turnbull W.B.

Subjects
synthetic biology, X ray diffraction, molecular assemblies
Abstract

The self-assembly of proteins into higher order structures is ubiquitous in living systems. It is also an essential process for the bottom-up creation of novel molecular architectures and devices for synthetic biology. However, the complexity of protein-protein interaction surfaces makes it challenging to mimic natural assembly processes in artificial systems. Indeed, many successful computationally designed protein assemblies are prescreened for "designability", limiting the choice of components. Here, we report a simple and pragmatic strategy to assemble chosen multisubunit proteins into more complex structures. A coiled-coil domain appended to one face of the pentameric cholera toxin B-subunit (CTB) enabled the ordered assembly of tubular supra-molecular complexes. Analysis of a tubular structure determined by X-ray crystallography has revealed a hierarchical assembly process that displays features reminiscent of the polymorphic assembly of polyomavirus proteins. The approach provides a simple and straightforward method to direct the assembly of protein building blocks which present either termini on a single face of an oligomer. This scaffolding approach can be used to generate bespoke supramolecular assemblies of functional proteins. Additionally, structural resolution of the scaffolded assemblies highlight "native-state" forced protein-protein interfaces, which may prove useful as starting conformations for future computational design.

Published
2019

27. SOFIA Far-infrared Imaging Polarimetry of M82 and NGC 253: Exploring the Supergalactic Wind

Author

Jones, T., Dowell, C., Lopez Rodriguez, E., Zweibel, E., Berthoud, M., Chuss, D., Goldsmith, P., Hamilton, R., Hanany, S., Harper, D., Lazarian, A., Looney, L., Michail, J., Morris, M., Novak, G., Santos, F., Sheth, K., Stacey, G., Staguhn, J., Stephens, I., Tassis, K., Trinh, C., Volpert, C., Werner, M., Wollack, E., and Team, H.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present far-infrared polarimetry observations of M82 at 53 and 154 μm and NGC 253 at 89 μm, which were taken with High-resolution Airborne Wideband Camera-plus (HAWC+) in polarimetry mode on the Stratospheric Observatory for Infrared Astronomy. The polarization of M82 at 53 μm clearly shows a magnetic field geometry perpendicular to the disk in the hot dust emission. For M82 the polarization at 154 μm shows a combination of field geometry perpendicular to the disk in the nuclear region, but closer to parallel to the disk away from the nucleus. The fractional polarization at 53 μm (154 μm) ranges from 7% (3%) off nucleus to 0.5% (0.3%) near the nucleus. A simple interpretation of the observations of M82 invokes a massive polar outflow, dragging the field along, from a region ~700 pc in diameter that has entrained some of the gas and dust, creating a vertical field geometry seen mostly in the hotter (53 μm) dust emission. This outflow sits within a larger disk with a more typical planar geometry that more strongly contributes to the cooler (154 μm) dust emission. For NGC 253, the polarization at 89 μm is dominated by a planar geometry in the tilted disk, with weak indication of a vertical geometry above and below the plane from the nucleus. The polarization observations of NGC 253 at 53 μm were of a insufficient signal-to-noise ratio for a detailed analysis.

Published
2019

28. The Far-infrared Polarization Spectrum of ρ Ophiuchi A from HAWC+/SOFIA Observations

Author

Santos, F., Chuss, D., Dowell, C., Houde, M., Looney, L., Lopez Rodriguez, E., Novak, G., Ward-Thompson, D., Berthoud, M., Dale, D., Guerra, J., Hamilton, R., Hanany, S., Harper, D., Henning, T., Jones, T., Lazarian, A., Michail, J., Morris, M., Staguhn, J., Stephens, I., Tassis, K., Trinh, C., Van Camp, E., Volpert, C., and Wollack, E.

Subjects
Astrophysics::Galaxy Astrophysics
Abstract

We report on polarimetric maps made with HAWC+/SOFIA toward ρ Oph A, the densest portion of the ρ Ophiuchi molecular complex. We employed HAWC+ bands C (89 μm) and D (154 μm). The slope of the polarization spectrum was investigated by defining the quantity {{ \mathcal R }}{DC}={p}D/{p}C, where p C and p D represent polarization degrees in bands C and D, respectively. We find a clear correlation between {{ \mathcal R }}{DC} and the molecular hydrogen column density across the cloud. A positive slope ({{ \mathcal R }}{DC} > 1) dominates the lower-density and well-illuminated portions of the cloud, which are heated by the high-mass star Oph S1, whereas a transition to a negative slope ({{ \mathcal R }}{DC} < 1) is observed toward the denser and less evenly illuminated cloud core. We interpret the trends as due to a combination of (1) warm grains at the cloud outskirts, which are efficiently aligned by the abundant exposure to radiation from Oph S1, as proposed in the radiative torques theory; and (2) cold grains deep in the cloud core, which are poorly aligned owing to shielding from external radiation. To assess this interpretation, we developed a very simple toy model using a spherically symmetric cloud core based on Herschel data and verified that the predicted variation of {{ \mathcal R }}{DC} is consistent with the observations. This result introduces a new method that can be used to probe the grain alignment efficiency in molecular clouds, based on the analysis of trends in the far-infrared polarization spectrum.

Published
2019

29. HAWC+/SOFIA Multiwavelength Polarimetric Observations of OMC-1

Author

Chuss, D., Andersson, B., Bally, J., Dotson, J., Dowell, C., Guerra, J., Harper, D., Houde, M., Jones, T., Lazarian, A., Lopez Rodriguez, E., Michail, J., Morris, M., Novak, G., Siah, J., Staguhn, J., Vaillancourt, J., Volpert, C., Werner, M., Wollack, E., Benford, D., Berthoud, M., Cox, E., Crutcher, R., Dale, D., Fissel, L., Goldsmith, P., Hamilton, R., Hanany, S., Henning, T., Looney, L., Moseley, S., Santos, F., Stephens, I., Tassis, K., Trinh, C., Van Camp, E., Ward-Thompson, D., and Team, H.

Subjects
Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We report new polarimetric and photometric maps of the massive star- forming region OMC-1 using the HAWC+ instrument on the Stratospheric Observatory for Infrared Astronomy. We present continuum polarimetric and photometric measurements of this region at 53, 89, 154, and 214 μm at angular resolutions of 5″, 8″, 14″, and 19″ for the four bands, respectively. The photometric maps enable the computation of improved spectral energy distributions for the region. We find that at the longer wavelengths, the inferred magnetic field configuration matches the “hourglass” configuration seen in previous studies, indicating magnetically regulated star formation. The field morphology differs at the shorter wavelengths. The magnetic field inferred at these wavelengths traces the bipolar structure of the explosive Becklin- Neugebauer/Kleinman-Low outflow emerging from OMC-1 behind the Orion Nebula. Using statistical methods to estimate the field strength in the region, we find that the explosion dominates the magnetic field near the center of the feature. Farther out, the magnetic field is close to energetic equilibrium with the ejecta and may be providing confinement to the explosion. The correlation between polarization fraction and the local polarization angle dispersion indicates that the depolarization as a function of unpolarized intensity is a result of intrinsic field geometry as opposed to decreases in grain alignment efficiency in denser regions.

Published
2019

30. Endothelial Cell Loss Following Cataract Surgery Using Continuous Curvilinear Capsulorhexis or Precision Pulse Capsulotomy

Author

Vital MC, Jong KY, Trinh CE, Starck T, and Sretavan D

Subjects
automated capsulotomy, zepto, corneal endothelium, Ophthalmology, RE1-994
Abstract

Mark C Vital,1 Kevin Y Jong,1 Clarise E Trinh,1 Tomy Starck,2 David Sretavan3 1Houston Eye Associates, Houston, TX, USA; 2UltraVision, San Antonio, TX, USA; 3Centricity Vision Inc., Carlsbad, CA, USACorrespondence: Mark C Vital, Houston Eye Associates, 2855 Gramercy Street, Houston, TX, 77025, USA, Tel +1 713 668 6828, Fax +1 832 553-7154, Email MVital@HoustonEye.comPurpose: To compare endothelial cell density (ECD), percentage of hexagonal cells (%Hex) and coefficient of variation (CV) in cell size following lens cataract surgery with phacoemulsification performed using Continuous Curvilinear Capsulorhexis (CCC) or Precision Pulse Capsulotomy (PPC).Patients and Methods: Sixty-seven subjects were randomly assigned to undergo lens cataract removal with the capsulotomy step performed using either CCC or PPC. Specular microscopy images were obtained pre-operatively, 1 month and 3 months after surgery. ECD, %Hex and CV were analyzed in a masked fashion by an independent reading center.Results: The mean percentage ECD loss at 1 month was 11.5% in the CCC group and 12.3% in the PPC group (P = 0.818; t-test). At 3 months, the mean percentage ECD loss was 11.7% in the CCC group and 12.4% in the PPC group (P = 0.815; t-test). The mean %Hex at 1 month was 54.3% in the CCC group and 54.7% in the PPC group (P = 0.695; t-test). At 3 months, the mean %Hex was 56.2% in the CCC group and 54.7% in the PPC group (P = 0.278; t-test). The CV at 1 month was 34.4% in the CCC group and 34.3% in the PPC group (P = 0.927; t-test). At 3 months, the CV was 32.7% in the CCC group and 33.4% in the PPC group (P = 0.864; t-test).Conclusion: No differences in ECD loss, %Hex and CV were observed between patients who received CCC or PPC. PPC use during cataract surgery does not result in any increased endothelial cell loss beyond that normally associated with this surgery.Keywords: automated capsulotomy, zepto, corneal endothelium

Published
2023

31. Primary Hepatic Schwannoma: Case Report and Literature Review

Author

Nguyen Thi Khuyen, Truong Quoc Thanh, Hoang Van Trung, Trinh Cong Thao, and Tran Nhu Tung

Subjects
Medicine (General), R5-920
Abstract

Primary hepatic schwannoma is an extremely rare tumor with a good prognosis. Preoperative diagnosis is often challenging due to nonspecific clinical symptoms and its rarity. Here, we report a case of a 56-year-old male patient misdiagnosed with malignant liver tumor, later identified as primary hepatic schwannoma. Furthermore, clinical and histopathological features of 19 cases of primary hepatic schwannoma are also documented. The age of the patients ranged from 38 to 72 years, with a mean age of 56.4 years, and the disease was more common in females. Patients typically presented without clinical symptoms and were not associated with neurofibromatosis type 1. Histopathological features of the tumor were similar to soft tissue schwannoma, characterized by a thick capsule consisting of Antoni A and Antoni B areas. Immunohistochemically, the tumor showed strong positivity and diffusely stained with S-100, while being negative for CD34, CD117, and SMA. Complete resection of the tumor was achieved in all patients. The prognosis was favorable, with no signs of recurrence. Follow-up examinations revealed disease-free survival ranging from 6 to 27 months. Differential diagnosis of primary hepatic schwannoma from malignant liver tumors and metastatic liver tumors can be made based on histopathological features and immunohistochemical staining with S-100.

Published
2023
Full Text
View/download PDF

35. The PROSPECT reactor antineutrino experiment

Author

Ashenfelter, J., primary, Balantekin, A.B., additional, Baldenegro, C., additional, Band, H.R., additional, Bass, C.D., additional, Bergeron, D.E., additional, Berish, D., additional, Bignell, L.J., additional, Bowden, N.S., additional, Boyle, J., additional, Bricco, J., additional, Brodsky, J.P., additional, Bryan, C.D., additional, Telles, A. Bykadorova, additional, Cherwinka, J.J., additional, Classen, T., additional, Commeford, K., additional, Conant, A.J., additional, Cox, A.A., additional, Davee, D., additional, Dean, D., additional, Deichert, G., additional, Diwan, M.V., additional, Dolinski, M.J., additional, Erickson, A., additional, Febbraro, M., additional, Foust, B.T., additional, Gaison, J.K., additional, Galindo-Uribarri, A., additional, Gilbert, C.E., additional, Gilje, K.E., additional, Glenn, A., additional, Goddard, B.W., additional, Hackett, B.T., additional, Han, K., additional, Hans, S., additional, Hansell, A.B., additional, Heeger, K.M., additional, Heffron, B., additional, Insler, J., additional, Jaffe, D.E., additional, Ji, X., additional, Jones, D.C., additional, Koehler, K., additional, Kyzylova, O., additional, Lane, C.E., additional, Langford, T.J., additional, LaRosa, J., additional, Littlejohn, B.R., additional, Lopez, F., additional, Lu, X., additional, Caicedo, D.A. Martinez, additional, Matta, J.T., additional, McKeown, R.D., additional, Mendenhall, M.P., additional, Miller, H.J., additional, Minock, J.M., additional, Mueller, P.E., additional, Mumm, H.P., additional, Napolitano, J., additional, Neilson, R., additional, Nikkel, J.A., additional, Norcini, D., additional, Nour, S., additional, Pushin, D.A., additional, Qian, X., additional, Romero-Romero, E., additional, Rosero, R., additional, Sarenac, D., additional, Seilhan, B.S., additional, Sharma, R., additional, Surukuchi, P.T., additional, Trinh, C., additional, Tyra, M.A., additional, Varner, R.L., additional, Viren, B., additional, Wagner, J.M., additional, Wang, W., additional, White, B., additional, White, C., additional, Wilhelmi, J., additional, Wise, T., additional, Yao, H., additional, Yeh, M., additional, Yen, Y.-R., additional, Zhang, A., additional, Zhang, C., additional, Zhang, X., additional, and Zhao, M., additional

Published
2019
Full Text
View/download PDF

39. Spatiotemporal Evolution of SARS-CoV-2 Alpha and Delta Variants during Large Nationwide Outbreak of COVID-19, Vietnam, 2021

Author

Nguyen Thi Tam, Nguyen To Anh, Trinh Son Tung, Pham Ngoc Thach, Nguyen Thanh Dung, Van Dinh Trang, Le Manh Hung, Trinh Cong Dien, Nghiem My Ngoc, Le Van Duyet, Phan Manh Cuong, Hoang Vu Mai Phuong, Pham Quang Thai, Nguyen Le Nhu Tung, Dinh Nguyen Huy Man, Nguyen Thanh Phong, Vo Minh Quang, Pham Thi Ngoc Thoa, Nguyen Thanh Truong, Tran Nguyen Phuong Thao, Dao Phuong Linh, Ngo Tan Tai, Ho The Bao, Vo Trong Vuong, Huynh Thi Kim Nhung, Phan Nu Dieu Hong, Le Thi Phuoc Hanh, Le Thanh Chung, Nguyen Thi Thanh Nhan, Ton That Thanh, Do Thai Hung, Huynh Kim Mai, Trinh Hoang Long, Nguyen Thu Trang, Nguyen Thi Hong Thuong, Nguyen Thi Thu Hong, Le Nguyen Truc Nhu, Nguyen Thi Han Ny, Cao Thu Thuy, Le Kim Thanh, Lam Anh Nguyet, Le Thi Quynh Mai, Tang Chi Thuong, Le Hong Nga, Tran Tan Thanh, Guy Thwaites, H. Rogier van Doorn, Nguyen Van Vinh Chau, Thomas Kesteman, and Le Van Tan

Subjects
COVID-19, coronavirus disease, SARS-CoV-2, severe acute respiratory syndrome coronavirus-2, coronaviruses, viruses, Medicine, Infectious and parasitic diseases, RC109-216
Abstract

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions.

Published
2023
Full Text
View/download PDF

40. Giải pháp tổ chức dữ liệu hạ tầng giao thông kết hợp bản đồ số 3D ứng dụng trong chuyển đổi số ngành giao thông vận tải tại thành phố Đà Nẵng

Author

Bùi Hồng Trung, Phan Vĩnh Nguyên, Trần Anh Kiệt, Nguyễn Hà Huy Cường, and Trịnh Công Duy

Subjects
bản đồ, csdl không gian, csdl thuộc tính, gis, postgresql, Technology
Abstract

Chuyển đổi số đang tác động mạnh mẽ trên mọi lĩnh vực, đóng vai trò quan trọng, là động lực chủ đạo cho sự phát triển của đất nước [1]. Đề án chuyển đổi số ngành Giao thông vận tải (GTVT) của thành phố Đà Nẵng đã nêu nhiệm vụ số hóa toàn bộ hạ tầng giao thông (HTGT) trên bản đồ số phục vụ công tác xây dựng và duy tu bảo dưỡng công trình giao thông, quản lý quy hoạch, chia sẻ cho các cơ quan có liên quan khai thác sử dụng [1, 2]. Tuy nhiên, dữ liệu HTGT rất đặc thù về độ lớn, cách thức lưu trữ, biến động theo thời gian, nếu biểu diễn dữ liệu và lưu trữ theo mô hình các hệ quản trị cơ sở dữ liệu truyền thống như các phần mềm quản lý hay sử dụng thì sẽ không đáp ứng được nhu cầu. Trong bài báo này, nhóm tác giả tiến hành nghiên cứu và đề xuất giải pháp tổ chức dữ liệu HTGT kết hợp bản đồ số nhằm đáp ứng nhu cầu ứng dụng tại sở GTVT thành phố Đà Nẵng.

Published
2023

42. Performance of a segmented 6Li-loaded liquid scintillator detector for the PROSPECT experiment

Author

Ashenfelter, J., primary, Balantekin, A.B., additional, Band, H.R., additional, Bass, C.D., additional, Bergeron, D.E., additional, Berish, D., additional, Bowden, N.S., additional, Brodsky, J.P., additional, Bryan, C.D., additional, Telles, A. Bykadorova, additional, Cherwinka, J.J., additional, Classen, T., additional, Commeford, K., additional, Conant, A., additional, Davee, D., additional, Deichert, G., additional, Diwan, M.V., additional, Dolinski, M.J., additional, Erickson, A., additional, Foust, B.T., additional, Gaison, J.K., additional, Galindo-Uribarri, A., additional, Gilje, K., additional, Hackett, B., additional, Han, K., additional, Hans, S., additional, Hansell, A., additional, Heeger, K.M., additional, Heffron, B., additional, Insler, J., additional, Jaffe, D.E., additional, Jones, D., additional, Kyzylova, O., additional, Lane, C.E., additional, Langford, T.J., additional, LaRosa, J., additional, Littlejohn, B.R., additional, Lopez, F., additional, Caicedo, D.A. Martinez, additional, Matta, J., additional, McKeown, R.D., additional, Mendenhall, M.P., additional, Minock, J., additional, Mueller, P.E., additional, Mumm, H.P., additional, Napolitano, J., additional, Neilson, R., additional, Nikkel, J.A., additional, Norcini, D., additional, Nour, S., additional, Pushin, D.A., additional, Qian, X., additional, Romero-Romero, E., additional, Rosero, R., additional, Surukuchi, P.T., additional, Trinh, C., additional, Tyra, M.A., additional, Wagner, J.M., additional, White, C., additional, Wilhelmi, J., additional, Wise, T., additional, Yeh, M., additional, Yen, Y.-R., additional, Zhang, A., additional, Zhang, C., additional, and Zhang, X., additional

Published
2018
Full Text
View/download PDF

43. Nghiên cứu xây dựng phương pháp phân tích Abamectin trên nền mẫu thủy sản và sản phẩm thủy sản bằng phương pháp sắc ký lỏng ghép hai lần khối phổ

Author

Trịnh Công Chức, Nguyễn Quốc Châu Thanh, Nguyễn Trọng Tuân, and Đặng Huỳnh Giao

Subjects
Abamectin, phân tích, sắc ký lỏng ghép khối phổ, thủy sản, Science
Abstract

Nghiên cứu xây dựng phương pháp xác định hàm lượng abamectin, một loại thuốc chống ký sinh trùng trên các nền mẫu thủy sản và sản phẩm thủy sản phục vụ nhu cầu kiểm tra, kiểm soát chất lượng trên đối tượng thủy sản nuôi. Trong nghiên cứu này, abamectin trong các nền mẫu tôm nguyên liệu, cá tra và tôm tẩm bột được chiết bằng kỹ thuật QueChERS (Quick-Easy-Cheap-Effective-Rugged-Safe) và phân tích bằng UPLC/MS/MS. Các thông số cần thiết như khoảng tuyến tính, giới hạn phát hiện (LOD), giới hạn định lượng LOQ, độ nhạy, độ chọn lọc, độ lặp lại, độ tái lặp và độ đúng được tiến hành khảo sát dựa trên các tiêu chí của các tổ chức trong nước và quốc tế. Phương pháp được xây dựng đã đáp ứng tốt nhu cầu phân tích, kiểm soát dư lượng trên thủy sản nuôi và sản phẩm sau chế biến.

Published
2023
Full Text
View/download PDF

44. Phát triển tư duy phản biện trong dạy học bậc đại học

Author

Trịnh Chí Thâm and Hồ Thị Thu Hồ

Subjects
Dạy học, đại học, sinh viên, tư duy phản biện, Science
Abstract

Trong nghiên cứu này, một số lí luận cơ bản về việc phát triển tư duy phản biện trong dạy học bậc Đại học được phân tích. Thông qua việc nghiên cứu tư liệu, dựa trên kết quả nghiên cứu, phản biện là một năng lực tư duy bậc cao chủ yếu dựa vào những phân tích và đánh giá thông tin một cách khách quan, có bằng chứng. Năng lực tư duy phản biện có những vai trò quan trọng gồm phát triển khả năng đưa ra quyết định, cải thiện năng lực giải quyết các vấn đề thực tiễn, tự đánh giá và chiêm nghiệm bản thân, làm nền tảng cho tư duy sáng tạo, nâng cao khả năng đương đầu và vượt qua thách thức, phát triển khả năng học tập suốt đời và hỗ trợ hoàn thiện các kĩ năng khác. Để phản biện hiệu quả, tư duy người học cần trải qua tiến trình bảy bước gồm: 1/ Tiếp nhận thông tin, 2/ Đưa ra lập luận, 3/ Tìm dẫn chứng, lí lẽ, 4/ Khẳng định lập luận, 5/ Thừa nhận, 6/ Hành động và 7/ Kiểm chứng, chiêm nghiệm.

Published
2023
Full Text
View/download PDF

45. Laboratory and Field-scale Evaluation of Low-pH Fe(II) Oxidation at Hughes Borehole, Portage, Pennsylvania

Author

William D. Burgos, Juliana F. Brown, and Trinh C. DeSa

Subjects
Environmental chemistry, Metallurgy, Oxidizing agent, Borehole, Sediment, Passive Treatment, Geotechnical Engineering and Engineering Geology, Acid mine drainage, Water Science and Technology
Abstract

The Hughes Borehole is located in the bituminous coal region of south-central Pennsylvania and drains an underground mine complex of ca. 2,950 ha. The borehole discharge averages approximately 63 L/s of acidic (pH 4, 230 mg/L acidity) mine drainage that contains elevated concentrations of Fe(II) (100 mg/L). Long-term monitoring of the site showed that biological Fe(II) oxidation occurred without human intervention and, over previous decades, has produced a 0.6 ha iron mound up to 2 m deep. On-mound channel reactors along with laboratory-scale gutter reactors were constructed to determine conditions that can exploit biological Fe(II) oxidation for passive treatment. Dissolved Fe(II) was much more efficiently oxidized from gutter reactors that contained iron mound sediment than ones without any sediment. Close to 100% of the dissolved influent Fe(II) was oxidized in 5–10 h and 75% of the total dissolved Fe was removed. In addition, the reactors performed better as the sediment aged, so that shorter residence times of 1–2 h were also capable of oxidizing substantial amounts of the influent Fe(II). The addition of surface area to the on-mound reactors improved Fe(II) oxidation at residence times of 30 min or less. The results of this study can be used to help design and build treatment systems for low-pH acid mine drainage (AMD) discharges.

Published
2010
Full Text
View/download PDF

47. Development of a miniaturised potentiostat for urea detection using the LMP91000

Author

Chi Tran Nhu, Phu Nguyen Dang, Tung Bui Thanh, and Trinh Chu Duc

Subjects
electrochemical system, LMP91000, urea detection, Science
Abstract

In this report, we develop a low-cost cyclic voltammetry platform for electrochemical analyses based on the LMP91000 integrated circuit (IC). The proposed system can be suitable to detect chemicals of interest in food safety or biology. The system includes three main blocks: the electrodes, electrochemical measuring circuit, and data acquisition. An algorithm was also built to process and display the data on the screen. Experiments are carried out with a standard redox solution containing Fe(II)/Fe(III) 5 mM and KCl 0.1 mM to evaluate system performance and make comparisons to the commercial potentiostat. The results show that the obtained signals from the proposed system and the commercial potentiostat device are similar. With applications of the miniaturised potentiostat, a non-enzymatic electrochemical biosensor for urea detection was fabricated on cobalt sulphide materials (CoS) synthesized via a microwave assisted method. The sensing performance for urea was determined by changing the oxidation potential peak of 100 mV. The sensor had a linear range from 1-8 mM corresponding to the urea concentration in blood. The sensor sensitivity was comparable (7.5 µAmM-1cm-2 ) to some previous publications. With the achieved results, the proposed system demonstrates potential in urea detection and can be a prototype to develop a commercial device for point-of-care testing in the future.

Published
2023
Full Text
View/download PDF

48. Effect of load forecasting uncertainties on the reliability of North American Bulk Power System

Author

Noha Abdel-Karim, John Moura, Elliott J. Nethercutt, Thomas Burgess, and Trinh C. Ly

Subjects
Normal distribution, Extreme weather, Peak demand, Business system planning, Probabilistic logic, Environmental science, Scenario analysis, Risk assessment, Reliability (statistics), Reliability engineering
Abstract

This paper highlights the importance of demand uncertainties and their associated risks to system planning and operations. It presents different approaches to modeling peak demand uncertainties. The work presented is part of a larger effort by the North American Electric Reliability Corporation (NERC) to demonstrate the benefits of applying a probabilistic approach to all NERC Assessment Areas to better understand emerging Bulk Power System (BPS) trends and reliability factors to promote optimum planning. NERC-wide aggregated actual and forecasted seasonal peak demands, along with their associated forecasting errors, are presented within this paper. A detailed individual assessment has been examined, applying statistical characterization and forecasting models used in a case study originally released by the Electric Reliability Council of Texas (ERCOT). For ERCOT, the results show higher forecast accuracy for the summer season compared to the winter season. This outcome is due to tail events in the peak demand normal distribution functions developed and unpredictable weather patterns. For the purpose of risk assessment validation, a Linear Predictive Coding (LPC)-based method is used to predict long-term demand. As a result, the developed distribution error has been utilized to construct scenario analysis for ERCOT's demand uncertainty. The findings of our analysis suggest the use of more event-driven outcomes, including extreme weather, unexpected load increases, and other worst-case scenarios.

Published
2014
Full Text
View/download PDF

49. Strength, thermal conductivity and sound absorption of cellular lightweight high calcium fly ash geopolymer concrete

Author

Athika Wongkvanklom, Patcharapol Posi, Pornnapa Kasemsiri, Vanchai Sata, Trinh Cao, and Prinya Chindaprasirt

Subjects
cellular lightweight geopolymer concrete, mechanical property, thermal property, sound absorption, Technology, Technology (General), T1-995
Abstract

In this research, the effects of foam content on mechanical property, thermal property and sound absorption of cellular lightweight geopolymer concrete (CLGC) were studied. The geopolymer mixtures were made with 15 M NaOH solution, sodium silicate/NaOH ratio (NS/NaOH) of 1.00, sand/ash ratio of 1.25, liquid/fly ash ratio of 0.4. The foam contents were varied from 2-12 %wt. The 28-day compressive strength of CLGCs of 2.7-57.8 MPa, unit weight of 844-2100 kg/m3, water absorption of 1.36-31.25%, porosity of 2.82-49.42%, thermal conductivity of 0.13-1.62 W/mK, and sound absorption coefficients of 0.05-0.5 were obtained. The CLGCs with 4% foam content, 28-day compressive strength of 38.9 MPa and unit weight of 1815 kg/m3is suitable for structural lightweight concrete complying to the requirements of ASTM C330/C330M-17a. Whereas the mix with 8 and 10 % foam contents with compressive strengths of 7.60 and 6.1 MPa, and unit weights of 1210 and 1060kg/m3are suitable for use as masonry lightweight concrete block in accordance with ASTM C331/C331M-17.

Published
2021
Full Text
View/download PDF

50. Thực trạng và giải pháp cho dạy học môn Lịch sử và Địa lí cấp trung học cơ sở ở tỉnh Cà Mau, theo chương trình giáo dục phổ thông năm 2018

Author

Hồ Thị Thu Hồ, Phạm Đức Thuận, Lê Văn Nhương, Trịnh Chí Thâm, Nguyễn Đức Toàn, Nguyễn Thị Thùy Mỵ, and Nguyễn Thị Ngọc Phúc

Subjects
Chương trình GDPT mới, dạy học, giải pháp, môn Lịch sử và Địa lí THCS, thuận lợi và khó khăn, Science
Abstract

Trong bài báo này, thực trạng dạy học môn Lịch sử và Địa lí cấp Trung học cơ sở được nghiên cứu theo chương trình giáo dục phổ thông năm 2018 tại các trường Trung học cơ sở trong địa bàn tỉnh Cà Mau. Với phương pháp nghiên cứu lý thuyết và nghiên cứu thực tế qua bảng hỏi, thảo luận nhóm, phỏng vấn sâu, bài viết đã đề cập và phân tích tình hình thực tế cũng như những thuận lợi và khó khăn của giáo viên trong việc dạy học môn Lịch sử và Địa lí theo chương trình giáo dục phổ thông mới. Từ đó một số giải pháp được đề xuất nhằm giúp giáo viên thực hiện nhiệm vụ này được thuận lợi và hiệu quả hơn.

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results