Nanoscale Fluid Transport: From Molecular Signatures to Applications

Motivated by the fact that many novel fluid transport phenomena have been discovered at nano length scales, in this thesis I use molecular dynamics simulations to investigate how a solid surface affects the fluid properties and fluid transport in nanochannels. My ultimate goal is to search for the molecular signatures of the macroscopic observations. From the understanding of the mutual relation between molecular properties and macroscopic observations, I learn how to tailor the fluid-solid interaction to improve the performance of practical applications including nano-fluidic devices, water desalination, energy storage, and shale gas exploration. For example, in Chapter 3 I find out that liquid water can slip on hydrophilic surfaces, which contradicts conventional knowledge. The responsible molecular signature appears to be the dynamical properties of interfacial water molecules, governed by the strength of water-surface interactions and surface morphology. When water molecules can migrate from one preferential adsorption site to the next without requiring hopping events, hydrodynamic liquid slip occurs. In Chapter 4 I illustrate that the structural and dynamical properties of the electric double layer formed near graphene electrodes are crucial to the performance of supercapacitors and capacitive desalination devices. By tailoring the electrode, thin and mobile electric double layer can be obtained that can tremendously enhance the capacitance of supercapacitors and the manner that capacitive desalination devices is operated. Finally, in the study of two-phase (water and methane) flow through muscovite nanopore reported in Chapter 5 I demonstrate that the flow pattern change not only affects the movement of methane with respect to that of water but also affects the pore structure, in particular its width. As muscovite has similar structure to illite, a clay often found in shale rocks, these results advance my understanding regarding the mechanism of water and gas transport in tight shale gas formations

Performance Evaluation for 59 Listed Electronic Corporations in Taiwan

Most previous studies concerning company performance evaluation focus merely on operational efficiency. Operational effectiveness, however, which might directly influence the survival of a company is usually ignored. As a result, this paper presents a study which uses an innovative two-stage data envelopment analysis (DEA) model that separates efficiency and effectiveness to evaluate the performance of 59 Listed corporations of the electronics industry in Taiwan. The empirical result of this paper is that a company with better efficiency doesn’t always mean that it has better effectiveness. There is no apparent correlation between these two indicators

Exploration of the memory effect on the photon-assisted tunneling via a single quantum dot: A generalized Floquet theoretical approach

The generalized Floquet approach is developed to study memory effect on electron transport phenomena through a periodically driven single quantum dot in an electrode-multi-level dot-electrode nanoscale quantum device. The memory effect is treated using a multi-function Lorentzian spectral density (LSD) model that mimics the spectral density of each electrode in terms of multiple Lorentzian functions. For the symmetric single-function LSD model involving a single-level dot, the underlying single-particle propagator is shown to be related to a 2 x 2 effective time-dependent Hamiltonian that includes both the periodic external field and the electrode memory effect. By invoking the generalized Van Vleck (GVV) nearly degenerate perturbation theory, an analytical Tien-Gordon-like expression is derived for arbitrary order multi- photon resonance d.c. tunneling current. Numerically converged simulations and the GVV analytical results are in good agreement, revealing the origin of multi- photon coherent destruction of tunneling and accounting for the suppression of the staircase jumps of d.c. current due to the memory effect. Specially, a novel blockade phenomenon is observed, showing distinctive oscillations in the field-induced current in the large bias voltage limit

Life-style orientation and contents of websites in personas industry

Electronic commerce challenges personas companies to design electronic system to increase interaction which leads to retain customers and increase sales. This exploratory study examines the correlation between lifestyle and emphasis on contents of website in personas industry. The study finds that market segment of lifestyle can be divided into four groups: ‘opinion leader’, ‘opinion follower’, ‘conservative’ and ‘challenger’. This paper tries to suggest a checklist to a vendor. We conclude that AIO can be a base of market segment in personas industry. We suggest some important factors which are included of the customized services, the safety of use factors, the store information and the menu illustration. Finally, we also conclude that the first three important factors of websites have significant influences on market segments of personas industry except for the store information factor.AIO, market segmentation, personas industry.

Optical activity and transport in twisted bilayer graphene: the essence of spatial dispersion effects

This study investigates optical activity and quantum transport in twisted bilayer graphene (TBG) systems, demonstrating that the former results from spatial dispersion effects. The transfer matrix method is used to solve the propagation of electromagnetic waves through two graphene layers that act as the coupling surfaces of a dielectric slab. The resulting optical conductivity tensor is decomposed into a local and a drag part, with the drag transverse conductivity $\sigma_{xy}^{(drag)}$ governing the TBG system's optical property. An effective continuum model is employed to analyze electron state formation and calculate relevant parts of the optical conductivity tensor. Correlation of electron motions leads to incomplete cancellation and a finite $\sigma_{xy}^{(drag)}$ in the chiral TBG lattice. The study also calculates DC conductivity, showing TBG supports quantum conductivity proportional to $e^2/h$ at the intrinsic Fermi energy.Comment: arXiv admin note: substantial text overlap with arXiv:2205.1267

Corporate Social Responsibility in Implementing Social Justice for Sustainable Development in Vietnam Today

Social responsibility is one of the issues that has been studied for a long time, but in fact corporate social responsibility activities, besides the achieved aspects, have still had many shortcomings that cause outrage in public opinion such as environmental pollution, counterfeit goods, imitated goods, inferior goods, infringing upon the interests of workers, interests of the State and the people, increasing gap between the rich and the poor, etc. These problems have been causing negative impacts on social life. Therefore, in addition to generalizing some relevant theoretical and practical issues, the article recommends some solutions to further enhance the corporate social responsibility in implementing social justice for sustainable development in Vietnam today. Keywords: justice, sustainability, enterprise, responsibility, society. DOI: 10.7176/RHSS/12-18-03 Publication date:September 30th 202

Visual Weather Temperature Prediction

In this paper, we attempt to employ convolutional recurrent neural networks for weather temperature estimation using only image data. We study ambient temperature estimation based on deep neural networks in two scenarios a) estimating temperature of a single outdoor image, and b) predicting temperature of the last image in an image sequence. In the first scenario, visual features are extracted by a convolutional neural network trained on a large-scale image dataset. We demonstrate that promising performance can be obtained, and analyze how volume of training data influences performance. In the second scenario, we consider the temporal evolution of visual appearance, and construct a recurrent neural network to predict the temperature of the last image in a given image sequence. We obtain better prediction accuracy compared to the state-of-the-art models. Further, we investigate how performance varies when information is extracted from different scene regions, and when images are captured in different daytime hours. Our approach further reinforces the idea of using only visual information for cost efficient weather prediction in the future.Comment: 8 pages, accepted to WACV 201

Regulation of axon repulsion by MAX-1 SUMOylation and AP-3.

During neural development, growing axons express specific surface receptors in response to various environmental guidance cues. These axon guidance receptors are regulated through intracellular trafficking and degradation to enable navigating axons to reach their targets. In Caenorhabditis elegans, the UNC-5 receptor is necessary for dorsal migration of developing motor axons. We previously found that MAX-1 is required for UNC-5-mediated axon repulsion, but its mechanism of action remained unclear. Here, we demonstrate that UNC-5-mediated axon repulsion in C. elegans motor axons requires both max-1 SUMOylation and the AP-3 complex β subunit gene, apb-3 Genetic interaction studies show that max-1 is SUMOylated by gei-17/PIAS1 and acts upstream of apb-3 Biochemical analysis suggests that constitutive interaction of MAX-1 and UNC-5 receptor is weakened by MAX-1 SUMOylation and by the presence of APB-3, a competitive interactor with UNC-5. Overexpression of APB-3 reroutes the trafficking of UNC-5 receptor into the lysosome for protein degradation. In vivo fluorescence recovery after photobleaching experiments shows that MAX-1 SUMOylation and APB-3 are required for proper trafficking of UNC-5 receptor in the axon. Our results demonstrate that SUMOylation of MAX-1 plays an important role in regulating AP-3-mediated trafficking and degradation of UNC-5 receptors during axon guidance

Cijepni soj virusa zaraznog bronhitisa patogeniji je za pileće zametke od divljeg soja 2575/98.

An avian infectious bronchitis virus (IBV) strain 2575/98 was attenuated using serial chicken embryo passage to become a vaccine in Taiwan. The aim of this study was to investigate the replication ability, pathogenicity, and tissue tropism of the wild and vaccine strains in chicken embryos. The embryos were inoculated with different titers of wild and vaccine strains. Quantification of virus in allantoic fluid was evaluated using real time RT-PCR. The results showed that the vaccine strain replicated in higher titers than the wild strain, and caused embryo death so quickly that only a few dwarfisms occurred. The embryos inoculated with wild and vaccine strains had similar lesions that were confined primarily to the chorionallantoic membrane (CAM), liver, and kidneys. The immunohistochemical data showed that IBV was present predominantly in the lungs, kidneys, and CAM. Although both strains caused hepatic damage, very few virus antigens were detected in the hepatic tissue. The pathogenicity of the vaccine becomes higher in embryos although it is lower in chickens than its wild strain. The vaccine strain could be used as a possible new vaccine candidate for IBV control.Virus zaraznog bronhitisa peradi soj 2575/98 bio je oslabljen uzastopnim pasažama u pilećim zametcima da bi poslužio kao cijepni soj u Tajvanu. Cilj je ovog rada bio istražiti mogućnost umnožavanja, patogenost i tropizam terenskog i cijepnog soja u pilećim zametcima. Zametci su bili inokulirani cijepnim sojem različitog titra. Količina virusa u alantoisnoj tekućini bila je određena RT-PCR-om u stvarnom vremenu. Rezultati su pokazali da se cijepni soj umnažao u višem titru od divljeg soja i prouzročio uginuće zametaka tako brzo da se uspjelo razviti svega nekoliko kržljavih. U inokuliranih zametaka, bez obzira na divlji ili cijepni soj, razvile su se slične promjene pretežito na korioalantoisnoj opni, jetrima i bubrezima. Imunohistokemijski je dokazano da se virus zaraznog bronhitisa prvenstveno nalazio u plućima, bubrezima i korioalantoisnoj opni. Iako su oba soja prouzročila oštećenja jetara, neznatna količina virusnog antigena bila je dokazana u jetrenom tkivu. Patogenost cijepnog soja bila je u zametcima jača, a u pilićima slabija od divljeg soja. Cijepni soj bi se mogao rabiti kao mogući kandidat za proizvodnju novog cjepiva protiv zaraznog bronhitisa