Regenerative Energie aus Solarstrahlung und aus dem atmosphärischem Temperaturgefälle

We discuss several methods to extract renewable energies for thermal power plants from solar radiation and from the atmospheric temperature gradient. Emphasis is on the thermodynamical aspect. We recommend for all methods: construction on the slope of a mountain, working substance air; in particular for a solar power plant: mounting of the turbine on top; and in particular for a power plant basing on the atmospheric temperature gradient: isothermic compression by a compressor mounted on top and isothermic expansion by a turbine mounted on bottom.     

Fluctuational electromagnetic interaction between a moving particle and a flat surface covered with a thin adsorbed film

The effect of a thin adsorbed film on the fluctuational electromagnetic tangential force of interaction between a moving nanoparticle and a flat solid surface was theoretically studied for the first time in a nonrelativistic approximation. Particular calculations were performed for a metal film on a dielectric and for a dielectric film on a metal. In both cases, the nanoparticle is assumed to be made of a nonmagnetic metal. It is shown that, at a normal temperature, the presence of an adsorbed film may lead to an increase in the tangential friction force by one or two orders of magnitude for a certain relation between the particle distance from the surface and the film thickness. In the case of a dielectric film on a metal substrate, a decrease in the temperature is accompanied by exponential decrease in the viscous friction. For a metal film on a dielectric substrate, the tangential force exhibits a quadratic dependence on the temperature.     

Linear variable optical filter-based ultraviolet microspectrometer

An IC-compatible linear variable optical filter (LVOF) for application in the UV spectral range between 310 and 400 nm has been fabricated using resist reflow and an optimized dry-etching. The LVOF is mounted on the top of a commercially available CMOS camera to result in a UV microspectrometer. A special calibration technique has been employed that is based on an initial spectral measurement on a xenon lamp. The image recorded on the camera during calibration is used in a signal processing algorithm to reconstruct the spectrum of the mercury lamp and the calibration data is subsequently used in UV spectral measurements. Experiments on a fabricated LVOF-based microspectrometer with this calibration approach implemented reveal a spectral resolution of 0.5 nm.     

Trends in CMOS technology and application development

The development trends in CMOS technology are discussed. It is clear that the trend in putting more and more transistors and memory bits on a chip will continue. The integration level will soon reach a point where the characteristics of a system are determined by the functional components on a single chip. There is likely to be detours on the technology roadmap, each driven by a different emphasis on the system functions implemented on a chip. While scaling CMOS transistors for density and performance will continue, there will be plenty of opportunities for improvement in system performance without pushing CMOS transistors to their limits.     

Characterization of silicon dioxide films on a 4H-SiC Si(0001) face by fourier transform infrared (FT-IR) spectroscopy and cathodoluminescence spectroscopy

We used Fourier transform infrared (FT-IR) spectroscopy to characterize silicon dioxide (SiO(2)) films on a 4H-SiC(0001) Si face. We found that the peak frequency of the transverse optical (TO) phonon in SiO(2) films grown on a 4H-SiC substrate agrees well with that in SiO(2) films grown on a Si substrate, whereas the peak frequency of the longitudinal optical (LO) phonon in SiO(2) films on a 4H-SiC substrate is red-shifted by approximately 50 cm(-1) relative to that in SiO(2) films on a Si substrate. We concluded that this red-shift of the LO phonon is mainly caused by a change in inhomogeneity due to a decrease in density in the SiO(2) films. Furthermore, cathodoluminescence (CL) spectroscopy results indicated that the channel mobility of the SiC metal-oxide-semiconductor field-effect transistor (MOSFET) decreases roughly in proportion to the increase in the intensity of the CL peak at 460 and 490 nm, which is attributed to the increase in the number of oxygen vacancy centers (OVCs). FT-IR and CL spectroscopies provide us with a large amount of data on OVCs in the SiO(2) films on a 4H-SiC substrate.     

From a local community to a global influence. How elBulli restaurant created a new epistemic movement in the world of haute cuisine

Location plays a major role in the building of artistic, technological or scientific movements that emerge in specific locations before achieving a worldwide reach. However, a deeper understanding is needed about the interplay of local/global knowledge dynamics in the epistemic construction of a movement. Based on an in-depth longitudinal study of a critical case, this article sheds light on these issues by analysing the case of ‘techno-emotional cuisine’, a global gastronomic movement initiated and led by chef Ferran Adrià and his team at the restaurant elBulli in Catalonia (in Northern Spain). The results suggest that the dynamics of formation of a new epistemic movement depend on the form and nature of the interactions between the local buzz and global pipelines, and on the capacity of the originating community to develop and diffuse the new rules and ‘episteme’ on a global scale while consolidating them locally.     

A general method for patterning gradients of biomolecules on surfaces using microfluidic networks

This report outlines a general method for the fabrication of immobilized gradients of biomolecules on surfaces. This method utilizes a microfluidic network that generates a gradient of avidin in solution and immobilizes this protein on the surface of glass or poly(dimethylsiloxane) by physical adsorption. The immobilized gradient of avidin is then translated into gradients of biotinylated ligands (e.g., small molecules, oligomers of DNA, polysaccharides) using the specific interaction between biotin and avidin. This method can also generate immobilized gradients of certain proteins and artificial polymers by a direct transfer of gradients from solution onto the surface. The major advantage of this method is that almost any type of molecule can, in principle, be immobilized in a well-defined surface gradient of arbitrary shape with dimensions of a few micrometers to a few centimeters. It is possible to tailor the precise shapes of gradients on surfaces from gradients in solution, either kinetically or competitively. Kinetic methods rely on controlling the time that the surface is exposed to the gradient in solution: when a single protein adsorbs from solution, the amount that adsorbs depends both on its concentration in solution and on the time allowed for adsorption. Competitive methods rely on exposure of the surface to a complementary gradient of two proteins in solution (In these experiments, the sum of the concentrations of the proteins in solution is independent of positions although the concentration of each, individually, depends on the position. In this procedure, the relative amount of each protein, at saturation on the surface, depends only on its concentration.).     

On the formation of carbon nanostructures on the steel surface of a reactor as a result of the decomposition of hydrocarbons in the low-temperature plasma. 1. Experimental setup,determination of basic mechanisms,estimation of the production rate

Results of experimental investigations on the formation of carbon nanostructures in a reactor as a result of the decomposition of hydrocarbons in a low-temperature plasma are presented. The influence of the internal geometry of the reactor, the temperature regimes, and the relative content of a reagent and an oxidizer in the working mixture on the formation of carbon nanostructures has been investigated. It was established that ordered carbon structures are formed on the surface of a metal containing iron and nickel. Data on the production rate of the process and the content of the structured carbon in the material obtained are presented.     

液晶显示的红、绿色光对视觉暗适应影响的比较研究

实验以受试持续注视液晶显示屏上较亮的色标后辩认低亮度兰道环所需要的时间作为测量暗适应水平的指标，考察了液晶显示的绿色光强度变化对视觉暗适应的影响，并对红、绿色光在同等强度上的间适应时间了比较。实验结果表明：（1）不同的强度的绿色光对暗适应的影响有显差异，光刺激强度越大，暗适应时间越长；（2）光刺激作用主要集中在视网膜中央宣传员的条件下，等亮度较弱的红光与绿光之间暗适应时间无显差异。     

环面上非测地线缠绕方程

本文分析了非测地线稳定缠绕的条件,用微分几何中法曲率和短程曲率概念给出了环面上非测地线缠绕方程,为缠绕弧形管提供了依据。      

Placement of effective work-in-progress limits in route-specific unit-based pull systems

Unit-based pull systems control the throughput time of orders in a production system by limiting the number of orders on the shop floor. In production systems where orders can follow different routings on the shop floor, route-specific pull systems that control the progress of orders on the shop floor by placing limits on the number of orders in (parts of) a routing, have shown to be effective in controlling throughput times. This is because route-specific pull systems are able to create a balanced distribution of the amount of work on the shop floor, which leads to shorter and more reliable throughput times. The placement of limits on work-in-progress in a route-specific pull system determines to a large extent the workload balancing capability of such a system. This paper shows how the placement of work-in-progress limits affects the workload balancing capability and thereby the throughput time performance of a route-specific unit-based pull system, namely POLCA.     

Wear Resistance Improvement of a 316L Austenitic Stainless Steel Treated by an Explosive Thin Film

A surface treatment technique by primary explosive was used on a 316L type austenitic stainless steel. Two explosive compositions, inducing a pressure of 3 GPa and 6 GPa respectively, were deposited in thin layer on flat samples. The residual microstructure is characterized by a profuse twinning whose density depends on the applied pressure and the depth below the treated surface. Moreover for the 6 GPa pressure a very thin surface layer of recrystallization in fine grains appears. The wear tests were performed on a pin on disc tribometer with loadings of 0.5 N and 4 N. In both cases, the wear resistance improvement reaches a factor of about 10 for the lower pressure and a factor 200 for the higher pressure. However, in the last case, the wear resistance improvement depends on the thin recrystallized layer leading to a benefit of a factor of 10, and mainly to the very thin layer of lead deposited by the treatment which acts as a solid lubricant.     

Measurements of mechanical properties of alpine skis in the laboratory

A few years ago Ian McMillan, the editor of the magazine SKIING, UK requested NEL to carry out tests on a batch of skis. For some time his magazine had been publishing information from a German testing laboratory on the mechanical properties of skis but he had decided to try to organise his own tests in the hope of giving his readers better information on different types of skis in a manner easier for them to understand. The author was asked to try to set up the tests because of personal interest in skiing so a meeting was arranged with Ian McMillan and his technical advisor, Gustaf Fischnaller. an Austrian who now runs a ski school at Glenshee, in Scotland. He has seen ski tests being carried out in Austria and could describe the test methods. After extensive discussion, a decision was taken on a range of tests designed to provide information on how the skis would behave on snow.     

Differences of drivers' reaction times according to age and mental workload

This study was designed to examine differences in reaction times of drivers of various age groups and to assess the influence of mental workload on reaction times. Experiments were performed on a simulated street and under other conditions to identify drivers with long reaction times and drivers whose reaction times are affected strongly by mental workloads while driving on a public road. Reaction times after hearing a buzzer were measured under five conditions: (1) sitting in a stationary vehicle, (2) executing mental calculations in a stationary vehicle, (3) driving on a simulated street, (4) executing mental calculations while driving on a simulated street, and (5) driving on a public road. Subjects were 10 drivers each of three age groups. Each experiment was performed by these subjects under the five conditions. Results showed that mental calculations increased the average reaction time for each age group. Mental calculations increased differences among age groups and individuals, and increased differences in respective drivers' individual performance. Mental calculations influenced elderly drivers' reaction times remarkably. Results also demonstrated that an experiment on a simulated street identified drivers who showed long reaction times on a public road.     

Single-molecule spectroscopic study of enhanced intrinsic phycoerythrin fluorescence on silver nanostructured surfaces

In this paper, we report on steady-state and time-resolved single-molecule fluorescence measurements performed on a phycobiliprotein, R-phycoerythrin (RPE), assembled on silver nanostructures. Single-molecule measurements clearly show that RPE molecules display a 10-fold increase in fluorescence intensity, with a 7-fold decrease in lifetime when they are assembled on silver nanostructured surfaces, as compared to control glass slides. The emission spectrum of individual RPE molecules also displays a significant fluorescence enhancement on silver nanostructures as compared to glass. From intensity and lifetime histograms, it is clear that the intensities as well as lifetimes of individual RPE molecules on silver nanostructures are more heterogeneously distributed than that on glass. This single-molecule study provides further insight on the heterogeneity in the fluorescence intensity and lifetimes of the RPE molecules on both glass and SiFs surfaces, which is otherwise not possible to observe using ensemble measurements. Finite-difference time-domain calculations have been performed to study the enhanced near-fields induced around silver nanoparticles by a radiating excited-state fluorophore, and the effect of such enhanced fields on the fluorescence enhancement observed is discussed.     

行波磁场在晶体生长过程中的研究进展

针对行波磁场的应用评述了其近几年理论和实验的研究进展,包括行波磁场原理、行波磁场发生器的设计、行波磁场在晶体生长过程中的效应。论述了在晶体生长过程中行波磁场引起的子午线流对导电熔体的稳定性、生长界面形貌和溶质分布的影响,指出了该领域当前研究存在的问题并展望了其发展趋势。     

Heat-transfer radiation in a selective gas flow impinging on a heating surface

The problem of computing the heat-transfer radiation in a selective gas flux impinging on a heating surface is examined on the basis of the Curtis-Godson approximation and a statistical model of the absorption band. Numerical results are presented for carbon dioxide. Their comparison with the results of a computation on the basis of a grey model showed a substantial difference in the magnitudes of the resultant fluxes on the boundary surfaces.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 36, No. 3, pp. 454–459, March, 1979.     

Two modes of bulk boiling of superheated liquid on a wire

Based on the results of qualitative analysis, the dynamics of a microlayer of liquid in two steady-state modes of motion of evaporation front propagating in a moderately superheated layer of liquid on a wire are described. Relations are suggested for the calculation of the front velocity depending on the degree of super-heating of liquid and on the heat flux density on the heating surface, as well as the condition of transition from nucleate to explosion boiling     

Octithiophene on Cu(III) and Au(III): formation and electronic structure of molecular chains and films

Adsorption and electronic structure of octithiophene (8T) molecules on Cu(III) and Au(III) surfaces are investigated using scanning tunneling microscopy (STM) and spectroscopy (STS) at room temperature. We find a large difference in adsorption behavior of 8T molecules on the two surfaces. At the initial stage of adsorption, 8T molecules are stabilized in the form of molecular chain on a terrace of Cu(III), whereas neither such chain structure nor isolated 8T molecules have been observed on a terrace of Au(III). By increasing the amount of adsorbed molecules, a disordered monolayer film is formed on Cu(III) while a well-ordered monolayer film is formed on Au(III). From the spectroscopic investigations using bias-dependent STM images and STS spectra and by comparing the data with theoretical calculations, it is found that the electronic property of 8T molecules in the molecular chain on Cu(III) is different from that of a free-standing 8T molecule while that in the monolayer film on Au(III) keeps original character of the free-standing 8T molecule. The present study shows that adsorption of 8T molecules on Cu(III) results in a formation of adsorption-induced states near the Fermi level.     

Full-Field Strain Rate Measurement by White-Light Speckle Image Correlation

Abstract:  This paper explains a numerical procedure to process sequences of digital images and to return a full-field evaluation of the strain rate. The processing procedure is based on a nonlinear least squares fitting performed globally, on the whole image, and simultaneously on several images. The use of a highly optimised code allows the analysis of long sequences in a few minutes. The results of calculations are presented as movies built by blending the colour maps of the measured strain field with the specimen pictures used in the correlation procedure. Our application is focused on studying the plastic behaviour of metals and, in particular, on highlighting any transient phenomena that might occur during yielding and strain-hardening phases on thin sheets used in the manufacture of sheet metals. A typical example for such phenomena is the Portevin-Le Châtelier effect, a repetitive yielding of alloys during plastic deformation.