Optimization and Form-finding of the Heavy Cable Suspending a Deck

The heavy spanning cable supporting a uniform deck is important in the design of suspension bridges. The analytic design method is presented in this paper. The problem depends on three non-dimensional parameters: the ratio of cable length to the horizontal spanning distance, the ratio of vertical to horizontal distance, and the ratio of deck density to cable density. Given these parameters, useful tables of maximum tension and sag are determined. There exists an optimum cable length for which the maximum tension is minimized. In addition, it is shown that continuous loads and discrete loads are equivalent if the number of evenly-spaced discrete loads are more than 10.   &nbsp

ENVIRONMENTAL SURROUNDINGS AND PERSONAL WELL-BEING IN URBAN CHINA

We examine the relationship between atmospheric pollution, water pollution, traffic congestion, access to parkland and personal well-being using a survey administered across six Chinese cities in 2007. In contrast to existing studies of the determinants of well-being by economists, which have typically employed single item indicators to measure well-being, we use the Personal Well-Being Index (PWI). We also employ the Job Satisfaction Survey (JSS) to measure job satisfaction, which is one of the variables for which we control when examining the relationship between environmental surroundings and personal well-being. Previous research by psychologists has shown the PWI and JSS to have good psychometric properties in western and Chinese samples. A robust finding is that in cities with higher levels of atmospheric pollution and traffic congestion, respondents report lower levels of personal well-being ceteris paribus. We find that a one standard deviation increase in suspended particles or sulphur dioxide emissions is roughly equivalent to a 12-13 percent reduction in average monthly income in the six cities. This result suggests that the personal well-being of China's urban population can be enhanced if China were to pursue a more balanced growth path which curtailed atmospheric pollution.China, Environment, Pollution, Personal Well-Being.

THE EFFECT OF DIFFERENT PLYOMETRIC-SQUAT TRAINING ON TAEKWONDO POWER DEVELOPMENT IN THE LOWER EXTREMITY

The purpose of this study was to investigate the effect on three different training methods by combining the typical plyometric training method (drop jump) and traditional weight training (112squat). The subjects were fifteen male high school athletes. The training duration for all subjects was eight weeks, and the frequency was twice a week. One Kistler force plate was used to record the power abilities of the subjects performing counter-movement jump (CMJ) and one PEAK camera (120 Hz) was also used to record the Axe-kicking movement time. Based on the results of this study, combining the vertical drop jump and horizontal drop jump with weight training could improve the maximum power and Axe-kick movement time. Therefore, it is important to consider the movement specific character when the muscular strength training of Taekwondo athletes

Parametric Analysis of Energy Absorption in Micro-particle Photophoresis in Absorbing Gaseous Media

The study deals with photophoresis of a spherical micro-particle suspended in absorbing gaseous media. Photophoretic motion of the particle stems from the asymmetric distribution of absorbed energy within the particle. By evaluating the so-called heat source function at various conditions, the study focuses on the effects of governing parameters on the energy distribution within the particle and their potential influences to the photophoresis. The results reveal that the increase in either particle size or absorptivity enhances the energy intensity on the illuminated (leading) side and tends to generate positive photophoresis. For a particle of low absorptivity, the energy distribution is dominated by particle refraction. Enhancing particle refractivity, the energy tends to be focused onto a certain spot area on the shaded (trailing) side and leads to a tendency of negative photophoresis. Increasing medium absorptivity significantly degrades the level of energy absorbed by the particle and in turn weakens the driving force of the particle photophoresis.Defence Science Journal, 2010, 60(3), pp.233-237, DOI:http://dx.doi.org/10.14429/dsj.60.34

Occurrence and Severity of the Viruses of Strawberry in Minnesota

Approximately 900 plants of commercially grown strawberries of 45 varieties and experimental seedling selections were collected from various parts of the state of Minnesota and indexed for the presence of viruses. Their presence in these plants was demonstrated by the appearance of symptoms in the indicator plant, Fragaria vesca L., after they were inarch-grafted. 93 % of the plants indexed were virus-infected. Based on symptoms, the viruses have been classified into 14 symptomtypes. It was found that mottle and mild yellow-edge were the two dominant viruses, whereas crinkle and vein chlorosis were of rare occurrence. There was no indication that certain symptom-types are associated with particular commercial varieties of strawberries or experimental seedling selections

Narrow ridge waveguide high power single mode 1.3-μm InAs/InGaAs ten-layer quantum dot lasers

Ten-layer InAs/In0.15Ga0.85As quantum dot (QD) laser structures have been grown using molecular beam epitaxy (MBE) on GaAs (001) substrate. Using the pulsed anodic oxidation technique, narrow (2 μm) ridge waveguide (RWG) InAs QD lasers have been fabricated. Under continuous wave operation, the InAs QD laser (2 × 2,000 μm2) delivered total output power of up to 272.6 mW at 10 °C at 1.3 μm. Under pulsed operation, where the device heating is greatly minimized, the InAs QD laser (2 × 2,000 μm2) delivered extremely high output power (both facets) of up to 1.22 W at 20 °C, at high external differential quantum efficiency of 96%. Far field pattern measurement of the 2-μm RWG InAs QD lasers showed single lateral mode operation

Characterization study of GaN-based epitaxial layer and light-emitting diode on nature-patterned sapphire substrate

[[abstract]]Chemical wet etching on c-plane sapphire wafers by three etching solutions (H3PO4, H2SO4, and H3PO4/H2SO4 mixing solution) was studied. Among these etching agents, the mixing H3PO4/H2SO4 solution has the fastest etching rate (1.5 μm/min). Interestingly, we found that H2SO4 does not etch the c-plane sapphire wafer in thickness; instead, a facet pyramidal pattern is formed on the c-plane sapphire wafer. GaN light-emitting diode (LED) epitaxial structure was grown on the sapphire wafer with the pyramidal pattern and the standard flat sapphire wafer. X-ray diffraction and photoluminescence measurement show that the pyramidal pattern on the sapphire wafer improved crystalline quality but augmented the compressive stress level in the GaN LED epilayer. The horizontal LED chips fabricated on the pyramidal-patterned sapphire wafer have a larger light output than the horizontal LED chips fabricated on the standard flat sapphire wafer by 20%.[[notice]]補正完畢[[incitationindex]]SCI[[booktype]]紙本[[booktype]]電子

Ni Interdiffusion Coefficient and Activation Energy in Cu6Sn5

Ni diffusion in Cu6Sn5 intermetallic compound was investigated. First, we successfully fabricated preferred-orientation Cu6Sn5 crystal by liquid-phase electroepitaxy (LPEE). Then, Ni/Cu6Sn5 diffusion couples were produced by sputtering from a Ni thin film onto the Cu6Sn5 crystal. Ni/Cu6Sn5 diffusion couples were annealed at different temperatures of 120A degrees C, 160A degrees C, 200A degrees C, 255A degrees C, 290A degrees C, and 320A degrees C for 2 h in a vacuum. The Ni atomic profile across the Ni/Cu6Sn5 interface was obtained by electron spectroscopy for chemical analysis (ESCA). From the Ni atomic profiles, the Matano method was used to evaluate the Ni interdiffusion coefficients ((D) over tilde (Ni)) in the Cu6Sn5 crystal obtained with different annealing temperatures, which then yields the activation energy for Ni diffusion in the Cu6Sn5 crystal at a particular Ni content. We found that, as Ni diffuses in the ternary Cu6-x Ni (x) Sn-5 compound phase, the activation energy of Ni interdiffusion decreases with the Ni content

The Influence of Solvent Selection upon the Crystallizability and Nucleation Kinetics of Tolfenamic Acid Form II

The influence of the solution environment on the solution thermodynamics, crystallizability, and nucleation of tolfenamic acid (TFA) in five different solvents (isopropanol, ethanol, methanol, toluene, and acetonitrile) is examined using an integrated workflow encompassing both experimental studies and intermolecular modeling. The solubility of TFA in isopropanol is found to be the highest, consistent with the strongest solvent–solute interactions, and a concomitantly higher than ideal solubility. The crystallizability is found to be highly dependent on the solvent type with the overall order being isopropanol < ethanol < methanol < toluene < acetonitrile with the widest solution metastable zone width in isopropanol (24.49 to 47.41 °C) and the narrowest in acetonitrile (8.23 to 16.17 °C). Nucleation is found to occur via progressive mechanism in all the solvents studied. The calculated nucleation parameters reveal a considerably higher interfacial tension and larger critical nucleus radius in the isopropanol solutions, indicating the higher energy barrier hindering nucleation and hence lowering the nucleation rate. This is supported by diffusion coefficient measurements which are lowest in isopropanol, highlighting the lower molecular diffusion in the bulk of solution compared to the other solutions. The TFA concentration and critical supersaturation at the crystallization onset is found to be directly correlated with TFA/isopropanol solutions having the highest values of solubility and critical supersaturation. Intermolecular modeling of solute–solvent interactions supports the experimental observations of the solubility and crystallizability, highlighting the importance of understanding solvent selection and solution state structure at the molecular level in directing the solubility, solute mass transfer, crystallizability, and nucleation kinetics

Influence of the Crystallisation Solution Environment on the Structural Pathway from Solute Solvation to the Polymorphic Forms of Tolfenamic Acid

The influence of the solution environment on the solution crystallisation of the conformational polymorphic forms I and II of tolfenamic acid is assessed through integration of multi-scale (molecular, cluster and crystallographic) modelling with polymorphic screening using polythermal crystallisation as a function of solvent selection. Solid-state analysis reveals the contrasting crystal chemistry with the strongest synthon involving hydrogen bonding synthons and π–π van der Waals interactions for forms I and II, respectively. Analysis of the molecular conformational energies reveals molecular structures for forms I and II to be very close which is matched by their calculated lattice energies. Crystallisation as a function of both solute concentration and solution cooling rate reveals form II to be mostly more preferred than form I. The higher stability of the form II conformer together with its easier conformational adjustment during the formation of form II crystals, is consistent with its greater crystallisability compared to the more stable form I. Solute concentration analysis of the relative stabilities of the two forms as a function of their sizes reveals that smaller cluster sizes are required to stabilise the crystal structure for form I with respect to form II. Polymorphic screening as a function of solvent confirms the predicted poor crystallisability of form I whose crystallisation is preferred at higher initial solute concentrations and lower cooling rates in polar solvents but less so for the more apolar solvent toluene, the latter being consistent with π–π solute/solvent interactions promoting the formation of hydrogen bonded solute/solute synthons at the expense of π–π interactions. Modelling work correlates well with the observed crystallisation behaviour, highlighting the importance of understanding solvent selection and solution state structure at the molecular-scale level for directing polymorphic outcomes, as confirmed by the higher crystallisability of the metastable form II