Effect Of Different Structures Research Articles

Magnetic property and stress study of barium hexaferrite thin films with different structures

M-type barium hexaferrite (BaM) thin films with different structures (ds100: single-layer 100 nm thick film; ds200: single-layer 200 nm thick film; db200: bilayer 200 nm thick film, where the thickness of each layer is 100 nm and the total film thickness is 200 nm) were deposited on (001) sapphire (Al2O3) substrate by radio frequency (RF) magnetron sputtering. Effects of different structures on the crystallographic, morphological, magnetic properties and stress were investigated in details. For the structure of ds100, BaM film processes platelet-like grains, which shows excellent magnetocrystalline anisotropy and large squareness ratio S⊥ (0.62). For the structure of ds200, there are a lot of acicular grains. Thus, the c-axis in-plane oriented and/or randomly oriented grains induce poor magnetocrystalline anisotropy. For the structure of db200, the platelet-like grains dominate the microstructure. Both squareness ratio S⊥ (0.67) and coercivity Hc⊥ (98.6 kA/m) of the db200 show the highest values among the three kinds of the film structures. In addition, with the increase of film thickness from 100 nm to 200 nm, the stress in film decreases gradually. Compared with the other structures, the bilayer 200 nm thick film (db200) obtains the smallest stress.

Effect of different structures of carbon supports for cathode catalyst on performance of direct methanol fuel cell

Carbon black (CB), multiwalled carbon nanotubes (MWNTs), reduced graphene oxide (rGO) are used as the cathode catalyst supports to investigate the effect on direct methanol fuel cell (DMFC) performance by using rotating disk electrode and fuel cell testing. The results of linear sweep voltammetry (LSV) and cyclic voltammetry (CV) show that the electrocatalytic activity sequence for oxygen reduction reaction (ORR) is Pt/rGO > Pt/MWNTs > Pt/C catalysts. The single cell tests results show that the maximum power densities of DMFC with Pt/C, Pt/MWNTs and Pt/rGO cathode catalysts are 74.0, 74.2 and 3.3 mW cm−2, respectively. The experimental results indicate that the performance of DMFC is substantially influenced by the structures of cathode catalyst supports. The significant differences in DMFCs performance are due to the compression ratios and hydrophilic/hydrophobic properties of catalyst layers with different structures of carbon supports, which strongly affect electrochemical active sites and mass transport in cathode catalyst layers. Long-term testing of DMFCs indicates that Pt/MWNTs exhibits superior stability. Considering the factors of the power and lifetime comprehensively, MWNTs is optimal candidate among the three investigated carbon supports.

Effects of different structures and allocations on fluid flow and heat transfer performance in 3D-IC integrated micro-channel interlayer cooling

3D-IC is getting increasingly attractive, as it improves speed and frequency and reduces power consumption, noise and latency. However, three-dimension (3D) integration technology brings a new serious challenge to chip thermal management with the power density increased exponentially. Interlayer micro-channel liquid cooling is a promising and scalable solution for high heat flux removal in 3D-IC. The effects of geometric parameters on fluid flow and heat transfer characteristics in interlayer micro-channel cooling for 3D-IC with triangular reentrant cavities (TRC) and fan-shaped reentrant cavities (FRC) are numerically investigated. 3D-IC with TRC and FRC for pitch=0.1/0.2mm and height=0.2mm are analyzed and compared with rectangular micro-channel (RMC) for 1cm2 heat areas. Results show that the heat rate and pressure drop distributions of each layer for length=5mm and pitch=0.2mm are more uniform. The micro-channels of pitch=0.1mm have better heat transfer performance, simultaneously cause the pressure drop and pumping power increasing sharply, which are undesirable and uneconomical for 3D-IC. For smaller Re, the micro-channels with surface enhancement structures TRC and FRC deteriorate heat transfer. While at the larger Re, heat transfer is enhanced, which can be attributed to heat transfer area increased, boundary layer thinned, boundary layer interrupted and chaotic advection by generating vortices. The 3D-IC with FRC-L5-P0.2 has better heat transfer performance and lowest pumping power, which is more suitable and economical for 3D-IC inter-layer cooling. For channel length of 10mm, the fluid temperature is higher in the last 5mm, which deteriorates heat transfer effect, simultaneously the longer length leads to pumping power and flow resistance enlarged. Besides, 3D-IC with FRC decreases the laminar stagnation zones and improves the heat transfer performance, due to owning bigger included angle of the expansion and constriction walls in channel.

Effects of Self-Assembled Monolayers with Different Chemical Groups on Ovarian Cancer Cell Line BehaviorIn Vitro

In addition to serving as a physical support, the extracellular matrix (ECM) actively influences cell behavior. However, the definitive effects of different chemical structures present in the ECM on cell behavior remain obscure. The current study aimed to investigate the effects of different chemical structures present in the ECM on cellular physiology using the ovarian cancer cell line SKOV-3 as a model. Self-assembled monolayers (SAMs) with different chemical modifications, including methyl (-CH3), hydroxyl (-OH), amino (-NH2), carboxyl (-COOH), and mercapto (-SH) groups, were used as microenvironmental models to explore the effects of different structures on SKOV-3 cells. The cell morphology, cell adhesion, cytotoxicity, and functional alterations in cancer cells cultured on different SAMs were analyzed. The results showed that SKOV-3 cells cultured on -NH2surfaces exhibited the largest contact area, whereas those on -CH3surfaces exhibited the smallest contact area and mostly rounded morphologies. Additionally, -NH2and -COOH promoted cell proliferation and adhesion, whereas CH3inhibited adhesion, leading to G1 arrest during the cell cycle and resulting in cell apoptosis. This study may provide useful information for reconstruction of the ECM and for controlling cell behavior in related areas of study.

Numerical simulation of gas-liquid two-phase flow in recycling cyclone separator with different structure

A numerical study of the droplet motion in the recycling cyclone separator is presented in this paper. The Reynolds stress model (RSM) for the single-phase and the coupling discrete random walk model are adopted for the two-phase. The pressure drop, separation efficiency velocity and turbulence parameters of the gas flow are described to study the effects of different structures on the separation performance of cyclones. The results show that recycling line can improve the efficiency of the recycling cyclone separator and reduce the pressure drop. The gap width and the size of baffle plate affect the separation property of the recycling cyclone. The rectangular-shaped intake behaves better than the cylinder-shaped one. However, the skirted baffle has little effect on the recycling cyclone separator. All the structural features make for a better understanding of the separation mechanism in the recycling cyclone separator. The numerical results are compared with the experimental data and good agreement can be observed.

Charge dependent photodynamic activity of alanine based zinc phthalocyanines

In this paper, to minimize the effects of different structure, three alanine-based zinc phthalocyanines (Pcs) of differing charges were engineered and synthesized with the same basic structure. On this premise, the relationship between nature of charge and photodynamic activity was studied. Besides, further verification and explanation of some inconsistent results were also carried out. The results showed that charge can influence the aggregation state, singlet oxygen generation ability and cellular uptake of Pcs, thereby affecting their photodynamic activity. In addition, the biomolecules inside cells may interact with Pcs of differing charges, which can also influence the aggregation state and singlet oxygen generation of the Pcs, and then influence the relationship between nature of charge and photodynamic activity.

Graded-index structures for high-efficiency solar thermophotovoltaic emitting surfaces.

This Letter presents a highly efficient emitter structure for solar thermophotovoltaic systems. The structure consists of a graded index on tungsten, shows a spectral efficiency of 59%, or 70% with the use of a back reflector, and is compared to other state-of-the-art emitter structures. The effects of different structures and periodicities on the efficiency of the emitter are explored, as well as the effect of a protective oxide coating. The causes of the antireflection properties of these structures are also explored.

Structure controlling and adsorption application of polyethersulfone porous microspheres prepared via electrospraying

The focus of this work is to control the structure of electrosprayed polymer microspheres and then study the effect of different structures on the microspheres’ adsorption properties. Scanning electron microscopy (SEM) coupled with image analysis software was employed to evaluate the size distributions and the structure of microspheres. According to the observation and analysis results, two types of polyethersulfone (PES) porous microspheres (perfect sphere-shaped and collapsed) were prepared via electrospraying technology by adjusting the solvent and polymer molecular weight. The porous PES microspheres can remove bisphenol A (BPA) from its aqueous solution effectively. Compared with collapsed microspheres, the rough microspheres had much higher specific surface area and better mobility in the BPA aqueous solution, so it showed a better adsorption capacity than that of collapsed microspheres. The solvent evaporation rate and the occurrence rate of phase separation significantly affect the structure and morphology of microspheres.

A study on ultraviolet protection properties of 100% cotton knit fabric: effect of fabric structure

In this paper, the effect of different structures of knit fabric on ultraviolet (UV) protection was studied. Different knit structures were investigated, which included single knits such as plain, pineapple, lacoste and other combinations of different knitting stitches of knit, tuck and miss as well as double-knit structure of half milano, full milano, half cardigan, full cardigan, 1 × 1 rib and interlock. The results showed that double-knit fabrics provide better UV protection than single-knit fabrics.

A facile route to modify ferrous phosphate and its use as an iron-containing resource for LiFePO4 via a polyol process.

This study introduces an economical and environmentally friendly way of synthesizing LiFePO4/C to be used as cathode material in lithium ion batteries via two processes: (1) the synthesis of LiFePO4/C cathode material using a low cost divalent precursor ferrous phosphate, Fe3 (PO4)2·8H2O, as iron source in a polyol process and (2) the modification of the morphology of this precursor by varying the reaction time in a coprecipitation process. The study examines the effects of different structures and morphologies of the precursor on the structure and electrochemical performance of the as-synthesized LiFePO4/C. The LiFePO4/C shows an excellent rate capability and cycle performance, with initial discharge capacities of 153, 128, and 106 mA h g(-1) at 1 C, 5 C, and 10 C. The capacity retention is respectively 98.7%, 98.2%, and 98.7%, after 10 cycles at the corresponding rates. The capacity retention remains at 97% even after 300 cycles at the rate of 10 C. The outstanding electrochemical performance can be attributed to the improved rate of Li(+) diffusion and the excellent crystallinity of synthesized LiFePO4/C powders through the modified precursor. Therefore, this is an economical and environmentally friendly way of synthesizing LiFePO4/C to be used as cathode material in lithium ion batteries.

Property changes of temperature-sensitive paint immobilized in acrylic polymer matrices

This study is aimed to investigate the effect of different structures of acrylic polymers on the properties of temperature-sensitive paint (TSP). TSP is composed of a temperature-sensitive luminophore and a polymer binder to fix the luminophore on a model substrate. Until now, the development of TSP has been focused primarily on searching for luminophores with high-temperature sensitivity and high luminescent intensity. However, recent studies revealed that polymers had a significant effect on TSP properties as well as luminophores. In this study, we systematically studied the effects of different structures of acrylic polymers on the temperature and pressure sensitivity and luminescent intensity of europium(III) thenoyltrifluoroacetonatetrihydrate (EuTTA)-based TSP. It was experimentally observed that EuTTA with acrylic polymers with longer straight side chain showed higher temperature sensitivity and lower luminescent intensity than those with shorter ones. In addition, an acrylic polymer with branched side chain presented lower sensitivity, higher pressure sensitivity, and higher luminescent intensity than that with straight side chain.

Effect of different structures on the gas sensing property of ZnO

We have successfully reported a new diamond-like morphology of zinc oxide (ZnO) structures via a simple hydrothermal method and discussed its probable growth mechanism. Compared with other morphologies of ZnO structures (microrods and nanosheets), nanodiamonds have excellent gas-sensing property owning to its large specific surface area, holding the perfect promise for ZnO powders as underlying gas-sensing materials. Furthermore, the as-prepared nanosheets assisted with the sodium citrate as an additive were found to show better gas-sensing property due to the smaller size than microrods. We found the positive role of the sodium citrate and reaction time in the growth of nanosheets and nanodiamonds respectively and the corresponding influences on growth mechanism were discussed.

A Review on the Fabrication of Polymer-Based Thermoelectric Materials and Fabrication Methods

Thermoelectricity, by converting heat energy directly into useable electricity, offers a promising technology to convert heat from solar energy and to recover waste heat from industrial sectors and automobile exhausts. In recent years, most of the efforts have been done on improving the thermoelectric efficiency using different approaches, that is, nanostructuring, doping, molecular rattling, and nanocomposite formation. The applications of thermoelectric polymers at low temperatures, especially conducting polymers, have shown various advantages such as easy and low cost of fabrication, light weight, and flexibility. In this review, we will focus on exploring new types of polymers and the effects of different structures, concentrations, and molecular weight on thermoelectric properties. Various strategies to improve the performance of thermoelectric materials will be discussed. In addition, a discussion on the fabrication of thermoelectric devices, especially suited to polymers, will also be given. Finally, we provide the challenge and the future of thermoelectric polymers, especially thermoelectric hybrid model.

유화제의 구조에 따른 W/O 에멀젼의 특성 및 안정도에 관한 연구

. Abstract: The W/O emulsion is widely used for cosmetics because of its w ater-proofing benefit and long-lasting moisturizing effect. However, because of low stability of the W /O emulsion, it is very important to control the con-centration of electrolyte and emulsifying agent, and ratio of w ater phase. Among these factors, we focused on the effects of different structures of emulsifying agents on the ch ange of stability. Emulsifying agents were sorted into polyglyceryl ester, silicone and sugar series. We also examined the emulsifyingability of emulsifier by changing the ratio of normal and silicon oil in the oil phase. Through these experimental results, we figured out the property of w/o emulsion depending on the types of emulsifiers, and observe d the stability of emulsion considering the change of particles and viscosity over time.Keywords: W/O emulsion, emulsifier, particle, stability, viscosity

Fabrication and implementation of nanodiamond lateral field emission diode for logic OR function

This article reports successful fabrication and characterization of vacuum microelectronic OR gate logic using nanodiamond lateral diode structures. Two identical sets of four nanodiamond lateral diodes with different numbers of emitters, viz., 125, 325, 2340 and 9360, and with equal anode–cathode spacing of ~3.5-μm were fabricated on silicon-on-insulator (SOI) wafers. First the fabricated lateral emitters were characterized for emission current scaling to examine the scaling effect of different structures with respect to the forward emission current. Then, two identical diodes were connected in a circuit using diode–resister logic to realize the logic OR function with a square wave as an input signal. The current scaling behavior, demonstrating 1μA current at 18, 15, 7 and 2.2V for 125-, 325-, 2340- and 9360-fingered emitter structures respectively, directly affects the logic OR response. These nanodiamond vacuum logic gates are promising for application in harsh environments.

Study on Dynamics Simulation of Rigid-Flexible Coupling for CNC Machine Tool

A virtual prototype model of five-axis CNC machine tool has been constructed. Through the ADAMS software, the process of the machine is simulated and the dynamic analysis is carried out. The experimental model analysis on the column of the machine is practised with the software ADAMS, the weak link of the column is found out and a modification scheme is put forward for the design of the column structure. Improvement of structure of the column can effectively raise the working accuracy .Currently, five-axis CNC machine tool is the only way to solve parts processing such as impeller, special propeller, turbine rotor , large diesel engine crankshaft ,etc. Therefore, it is very important to carry out the dynamic analysis of the five axis CNC machine. In this paper, a rigid-flexible multi-body dynamics model for a five-axis CNC machine tool is set up, in which the column parts are modeled by flexible bodies. Aimed at the improvement of the machining accuracy, the effect of different structures of column are analyzed.

The Impacts of Ignoring a Crossed Factor in Analyzing Cross-Classified Data

Cross-classified random-effects models (CCREMs) are used for modeling nonhierarchical multilevel data. Misspecifying CCREMs as hierarchical linear models (i.e., treating the cross-classified data as strictly hierarchical by ignoring one of the crossed factors) causes biases in the variance component estimates, which in turn, results in biased estimation in the standard errors of the regression coefficients. Analytical studies were conducted to provide closed-form expressions for the biases. With balanced design data structure, ignoring a crossed factor causes overestimation of the variance components of adjacent levels and underestimation of the variance component of the remaining crossed factor. Moreover, ignoring a crossed factor at the kth level causes underestimation of the standard error of the regression coefficient of the predictor associated with the ignored factor and overestimation of the standard error of the regression coefficient of the predictor at the (k−1)th level. Simulation studies were also conducted to examine the effect of different structures of cross-classification on the biases. In general, the direction and magnitude of the biases depend on the level of the ignored crossed factor, the level with which the predictor is associated at, the magnitude of the variance component of the ignored crossed factor, the variance components of the predictors, the sample sizes, and the structure of cross-classification. The results were further illustrated using the Early Childhood Longitudinal Study-Kindergarten Cohort data.

QSAR Studies on Active Adducts of Dialkylamines and Cyclic Anhydride as Diesel Wax Anti-settling Additives

The relationship between the structure of adducts of dialkylamines and cyclic anhydride and their activity as wax anti-settling additives (WASA) for diesel was investigated by using quantitative structure activity relationship (QSAR). Associated with poly(ethylene-co-vinyl acetate), the four tested compounds revealed a range of decreasing of cold filter plugging points 2–8°C. The mechanisms of the additive actions are explained. Furthermore, the influences of parameters of molecular descriptors on the QSAR were considered. As a result, the total dipole of the molecular descriptors is the most important descriptor of adducts of dialkylamines and cyclic anhydride as WASA. And the obtained optimized QSAR model was statistically significant with the leave-out-one cross-validation tests: coefficient square q 2 = 0.773, non-cross validated coefficient square r 2 = 0.963. Based on such an optimized QSAR model, the effect of different structures of adducts of dialkylamines and cyclic anhydride as WASA can be studied using the QSAR code, which could provide a useful guideline for the next synthesis of novel compounds.

Hot beds of forensic psychiatry: Psychiatric intensive care units within medium security

Aims: To conduct a survey investigating the provision of psychiatric intensive care within NHS medium secure units in England and Wales, gaining preliminary information about PICU size and clinical structure, and using this information to inform a discussion regarding PICU provision in medium security.Method: A postal survey was conducted.Results: A total of 30 MSUs were identified. The three groups of MSU differed significantly in size. Half of the MSUs surveyed either had a PICU or were developing one. There was a great variation in clinical service structure.Discussion: There appears to be a growing trend for the provision of intensive care within medium security. Possible explanations for this movement are discussed. Reasons for PICUs not being developed are also explored. Forensic psychiatry needs to consider whether the national standards are appropriate for medium security. Further research is required to understand the reasons for the changing practice that we have identified, to develop a base of knowledge to inform service structure and to investigate the effects of different structures on clinical outcomes.

Solar wind drivers of large geomagnetically induced currents during the solar cycle 23

In this paper we investigate the interplanetary drivers of the largest geomagnetically induced currents (GIC) during the solar cycle 23. Interplanetary coronal mass ejections (ICMEs) are the major causes of intense geomagnetic storms and large GIC. In particular, in this work we examine the effectiveness of different structures embedded in an ICME (namely sheath regions, ejecta, and boundary layers) in causing large GIC. It was found that when an ICME interacts with the Earth's magnetosphere the most intense GIC activity is likely to take place during the passage of the turbulent sheath region. The effectiveness of sheath regions in driving large GIC is possibly due to their capability to trigger substorms and to drive intense directly driven ionospheric activity. We also investigated the relationships between different solar wind parameters and the GIC amplitudes. The best correlation with the GIC amplitudes was found with the solar wind electric field and the epsilon parameter. Ejecta‐associated GIC seem to require an on‐going magnetospheric Dst storm while sheath regions and boundary layers can cause large GIC even when no activity is taking place in terms of Dst. Interestingly, four of the nine ejecta‐associated GIC took place during the recovery phases of a intense magnetic storm (but when Dst still was having storm time values below −50 nT).