2,258 research outputs found
RO PRETREATMENT USING HYDRATE BASED ICE DESALINATION PROCESS
Department of Urban and Environmental Engineering(Environmental Science and Engineering)There are a variety of methods for seawater desalination, and seawater desalination method through ice-freezing also exists. This study discusses freezing desalination as a new method to combine direct contact freezing and indirect contact freezing. It is the first method as well to generate ices by utilizing CO2 Hydrate itself as refrigerant. This study explores HBID (Hydrate Based Ice Desalination)process.In HBID process, hydrate dissociation energy is used for cooling down water temperature and finally making ice. There are three factors freezing energy of HBID system. Joule-Thomson Effect, endothermic energy of carbon dioxide emission and endothermic energy of hydrate dissociation. The endothermic energy of hydrate dissociation is most dominant proposition as the major freezing energy of HBID system among the three factors.TheHBID process rejection efficiency increased as the NaClconcentration of feed water increased. However, when the NaCl concentration of feed water decreased the produced water quantitydecreased. In case of 10, 20 and 50ppm humic acid solution treatment, the rejection is above 70%. .HBID process is not significantly influenced by impurities such as the concentration of ion or organic matters,It has huge advantage to be utilized as the preconditioning process of membrane separation when treating high salinity waste water such as RO brineand Shale gas drawback water. In the case of cation analysis every cation rejection is higer than 50%.It also have more than 50% of performance in treatment efficiency of B3+ with the highest difficulties in treatment so they can be easily utilized in the front side of RO. Therefore, the development of HBID technology can be utilized alone in the process of seawater desalination or waste water treatment to contribute to generating pure water and decreasing the volume of waste water such as RO brine.ope
Transport and Kinetic Phenomena Linked to Power Performance of Lithium-Ion Batteries.
While energy density of a Li-ion cell depends on the choice of Li-ion active materials, power density depends on cell design and a set of well-balanced transport and kinetic material properties. Furthermore, the Li-ion cell rate capability improvement often comes at the expense of underutilizing available energy due to safety and cycle-life constraints. Hence, in this study, various transport and kinetic phenomena occurring inside a cell are examined to optimize the cell power performance.
Lithium-ion battery active materials are polycrystalline consisting of crystallites of varying size and orientation separated by grain boundaries. To investigate the grain boundary influence on battery performance, a single polycrystalline particle Li-ion cell model is developed. A Voronoi grain size distribution is employed in generating polycrystalline particles. Under galvanostatic and potentiodynamic cycling conditions, intercalation-induced stress, effective Li+ diffusivity, and capacity utilization are examined. It is found that the effective Li+ diffusivity is highly correlated with the grain boundary density while the maximum intercalation-induced stress depends on both the grain boundary density and the network structure. In addition, the particle capacity utilization improves with increasing grain boundary density, especially at high C-rates.
During cycles, many Li-ion active materials undergo a volumetric strain that may cause the material to fracture. On the other hand, the stress field has a benefit of enhancing Li+ diffusivity inside active materials. To estimate the intercalation-induced stress level, an in-situ AFM system is utilized in measuring particle morphological changes during cycles. Furthermore, a numerical method is used to quantify the Li+ diffusivity enhancement caused by the intercalation-induced stress field.
The rate capability of a Li-ion cell depends on multiple transport and kinetic phenomena occurring inside the cell, and the rates at which such phenomena occur depend on cell material properties. To understand how a cell electrochemical dynamic response changes with material properties, a sensitivity analysis of transport and kinetic parameters on cell performance is performed. It is found that different types of material properties have a significant influence on specific parts of a cell operating potential profile. Moreover, given a set of material properties, associated overpotentials are quantified.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/107146/1/hansw_1.pd
Bocavirus Infection in Hospitalized Children, South Korea
This study presents the first evidence of human bocavirus infection in South Korean children. The virus was detected in 27 (8.0%) of 336 tested specimens, including 17 (7.5%) of 225 virus-negative specimens, collected from children with acute lower respiratory tract infection
Clinical Approach to the Standardization of Oriental Medical Diagnostic Pattern Identification in Stroke Patients
In Korea, many stroke patients receive oriental medical care, in which pattern-identification plays a major role. Pattern-identification is Oriental Medicine's unique diagnostic system. This study attempted to standardize oriental medical pattern-identification for stroke patients. This was a community-based multicenter study that enrolled stroke patients within 30 days after their ictus. We assessed the patients' general characteristics and symptoms related to pattern-identification. Each patient's pattern was determined when two doctors had the same opinion. To determine which variables affect the pattern-identification, binary logistic regression analysis was used with the backward method. A total of 806 stroke patients were enrolled. Among 480 patients who were identified as having a certain pattern, 100 patients exhibited the Fire Heat Pattern, 210 patients the Phlegm Dampness Pattern, nine patients the Blood Stasis Pattern, 110 patients the Qi Deficiency Pattern, and 51 patients the Yin Deficiency Pattern. After the regression analysis, the predictive logistic equations for the Fire Heat, Phlegm Dampness, Qi Deficiency, and Yin Deficiency patterns were determined. The Blood Stasis Pattern was omitted because the sample size was too small. Predictive logistic equations were suggested for four of the patterns. These criteria would be useful in determining each stroke patient's pattern in clinics. However, further studies with large samples are necessary to validate and confirm these criteria
Nanopores of carbon nanotubes as practical hydrogen storage media
We report on hydrogen desorption mechanisms in the nanopores of multiwalled carbon nanotubes (MWCNTs). The as-grown MWCNTs show continuous walls that do not provide sites for hydrogen storage under ambient conditions. However, after treating the nanotubes with oxygen plasma to create nanopores in the MWCNTs, we observed the appearance of a new hydrogen desorption peak in the 300ā350 K range. Furthermore, the calculations of density functional theory and molecular dynamics simulations confirmed that this peak could be attributed to the hydrogen that is physically adsorbed inside nanopores whose diameter is approximately 1 nm. Thus, we demonstrated that 1 nm nanopores in MWCNTs offer a promising route to hydrogen storage media for onboard practical applications
The Effect of Target Height on the Trunk, Pelvis, and Thigh Kinematics in the Taekwondo Roundhouse Kick
Palladium Catalysts for Dehydrogenation of Ammonia Borane with Preferential BāH Activation
Cationic Pd(II) complexes catalyzed the dehydrogenation of ammonia borane in the most efficient manner with the release of 2.0 equiv of H_2 in less than 60 s at 25 Ā°C. Most of the hydrogen atoms were obtained from the boron atom of the ammonia borane. The first step of the dehydrogenation reaction was elaborated using density functional theory calculations
Body extract of tail amputated zebrafish promotes culturing of primary fin cells from glass catfish
The most spectacular regenerative events in vertebrates are epimorphic regeneration. In this study, interestingly, a whole-body extract 24 h after tail amputation enhanced primary cell growth and viability compared to that of a non-tail amputated body. Additionally, these effects of extract treatment in vitro were dose-dependent occurring at concentrations of 0.02, 0.05 and 0.1 mg/ml. This is the first in vitro study on the interaction between primary fin cells from glass catfish and tail amputated body extracts of zebrafish. These results provide an essential knowledge base for rational approaches to tissue and organ regeneration.Keywords: Cell growth, cell viability, extract, glass catfish, regeneration, zebrafishAfrican Journal of Biotechnology Vol. 12(12), pp. 1449-145
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