Optische in situ Schichtdickenmessung in Bedampfungsanlagen. Optical in situ film thickness monitoring in coating systems

Optical film thickness monitoring is more precise than crystal monitoring. The optical measurement makes use of the fact that the intensity of a monochromatic light beam which is reflected on a film will change periodically with increasing film thickness. The measurement is performed at an exchangeable test glass that is positioned beside the substrates and is therefore coated in the same way as the substrates. The accuracy of cut‐off is achieved by a “fit” of a theoretical curve shape to the measured values. Order filters are used to ensure that, at a certain wavelength, higher deflection orders do not influence the measurement when a monochromator grating is used.     

Trends in alcohol-impaired driving in Canada

While a general decreasing trend in the number of persons killed in a traffic crash involving a drinking driver has occurred in Canada since the 1980s, it is evident that much of this decrease occurred in the 1990s. Since 2002, less progress has been made as the number of persons killed in crashes involving drinking drivers remains high. To better understand the current situation, this paper describes trends in drinking and driving in Canada from 1998 to 2011 using multiple indicators based on data collected for the Traffic Injury Research Foundation's (TIRF) Road Safety Monitor (RSM), the National Opinion Poll on Drinking and Driving, and trends in alcohol-related crashes based on data collected for TIRF's national Fatality Database in Canada. There has been a continued and consistent decrease in the number of fatalities involving a drinking driver in Canada. This remains true when looking at the number of fatalities involving a drinking driver per 100,000 population and per 100,000 licensed drivers. This decreasing trend is also still apparent when considering the percentage of persons killed in a traffic crash in Canada involving a drinking driver although less pronounced. Data from the RSM further show that the percentage of those who reported driving after they thought they were over the legal limit has also declined. However, regardless of the apparent decreasing trend in drinking driving fatalities and behaviour, reductions have been relatively modest, and fatalities in crashes involving drivers who have consumed alcohol remain high at unacceptable levels.     

Natural radioactivity in drinking water in private wells in Finland

Natural radioactivity in drinking water was determined in population-based random study of 472 private wells. The mean concentrations of (222)Rn, (226)Ra, (234)U, (238)U, (210)Pb and (210)Po in drilled wells were 460, 0.05, 0.35, 0.26, 0.04 and 0.05 Bq l(-1), and in wells dug in the soil were 50, 0.016, 0.02, 0.015, 0.013 and 0.007 Bq l(-1), respectively. Approximately 10% of the drilled wells exceeded a radon concentration of 1000 Bq l(-1) and 18% a uranium concentration of 15 microg l(-1). The mean annual effective dose from natural radionuclides for a drilled well user was 0.4 mSv and 0.05 mSv for a user of a well dug in the soil. The effective dose arising from (222)Rn was 75% of the total of all natural radionuclides for drilled well users. As regards long-lived radionuclides, (210)Po and (210)Pb caused the largest portion of the effective dose. The dose arising from (238)U, (234)U and (226)Ra was only 8% of the total of all natural radionuclides.     

Parallelism in interactive operations in finite-element simulation

The parallelizing of interactive operations that are part of the finite-element simulation of electromagnetic fields is examined. The total solution time in finite-element analysis is the time assigned to (1) preprocessing, (2) assembling and solving the matrix equation, and (3) postprocessing the solution. In the analysis the tasks of pre- and postprocessing are interactive, with the user sitting at a terminal and specifying various parameters. Two computer routines are identified as the most frequently used in an interactive setting: one identifies a triangle pointed out by a user, and the other identifies a node pointed out by a user. Procedures for parallelizing them are given. A way of parallelizing the plotting of equipotentials and drawing the device, which are frequently required in interactive use, is also presented. It is shown that this method may have more to offer in reducing the nuisance of waiting for certain computer responses compared with the more commonly adopted approach of parallelizing the solver section of a finite-element program     

Fixation in finite populations evolving in fluctuating environments

The environment in which a population evolves can have a crucial impact on selection. We study evolutionary dynamics in finite populations of fixed size in a changing environment. The population dynamics are driven by birth and death events. The rates of these events may vary in time depending on the state of the environment, which follows an independent Markov process. We develop a general theory for the fixation probability of a mutant in a population of wild-types, and for mean unconditional and conditional fixation times. We apply our theory to evolutionary games for which the payoff structure varies in time. The mutant can exploit the environmental noise; a dynamic environment that switches between two states can lead to a probability of fixation that is higher than in any of the individual environmental states. We provide an intuitive interpretation of this surprising effect. We also investigate stationary distributions when mutations are present in the dynamics. In this regime, we find two approximations of the stationary measure. One works well for rapid switching, the other for slowly fluctuating environments.     

An experiment in genetic optimization in lens design

Abstract

A genetic algorithm and its application in lens design is studied. A combined algorithm is also presented which includes both a genetic algorithm (GA) and a damped least squares (DLS) method. The convergence property of a GA in lens design is demonstrated: first of all, a GA-generated design is obtained without artificial intervention, then, the aberration correction is completed by DLS, and the result is close to the GA-generated design.     

Thermal effects in compressible viscous flow in a capillary

The thermal effects for a compressible viscous flow in a capillary have been calculated by solving the equation of energy, where a parabolic profile is assumed for the axial flow velocity. It is shown that, in general, the temperature changes are small (a few millikelvins), consistent with the current assumption of an isothermal flow, except in the case of a critical, i.e., very compressible, fluid where the cooling can be substantial. This effect is demonstrated numerically on the basis of a flow of ethylene in nearly critical circumstances.Paper dedicated to Professor Joseph Kestin.     

Heat exchange in a tube in the presence of vibrational relaxation in the gas

The temperature distribution of a heat-liberating wall of a circular tube, in which a Poisseuille gas flows, is obtained. The influence of nonequilibrium excitation and relaxation of the vibrational degrees of freedom of the diatomic gas on the wall temperature is taken into account.Translated from Inzhenerno-Pizicheskii Zhurnal, Vol. 19, No. 5, pp. 861–869, November, 1970.     

Ecological compensation in spatial planning in Italy

Ecological compensation or biodiversity offsets are increasingly recognized as a key element for environmental sustainability; however, more attention has been paid so far to compensation applied at the project level rather than to spatial planning. Meanwhile, there is a growing acknowledgement that extensive environmental depletion is being caused by the cumulative effects of small developments allowed by spatial/land use plans. This paper aims to collect empirical evidence on the requirements for ecological compensation at a strategic level of decision-making – spatial planning – in Italy. Results indicate that spatial plans are increasingly introducing offset requirements for residual impacts of new urban developments; however, methodological and operational aspects are not sufficiently addressed and enforcement mechanisms appear weak. The lack of legal frameworks and of established methods appears to be the main element currently hindering biodiversity offset implementation at the planning level. It is suggested that, in the Italian context, a way to foster better implementation is the design of environmental stewardship schemes involving farmers, developers and planning authorities.     

水中脉冲电晕放电测试系统

建立了一套水中电晕放电测试系统．由高速摄影系统、电参数测量系统和压力测量系统组成．高速摄影系统由GSJ转镜式高速摄影仪和德国产Pentazet35型摄影仪等组成,最高拍摄频率分别为250万幅／s和4万幅／s．电参数测量系统由高压表、电阻分压器、同轴分流器和Tektronix THS730A示波器组成．详细分析了整个系统的敏感设备、干扰源及其传播途径,并提出了相应的控制措施．压力测试系统主要有压电式传感器等组成．     

Risk Evaluation in Decision Making in Risk Situations

We analyze the components of uncertainty in decision making and consider a risk evaluation model in decision making in a risk situation in economic activities. A modified cost-benefit criterion is proposed for decision making for implementing a project, taking into account the average losses due to wrong decisions. __________ Translated from Izmeritel'naya Tekhnika, No. 9, pp. 27–29, September, 2005.     

Structural changes in S&T research in India

Before India became an independent country, its scientists and policy makers could foreseethe importance of science in its development, and accordingly a number of research anddevelopment (R&D) institutions were established. However during these five decades ofindependence, the choice between basic sciences and technology was always a subject of debate.It will be appropriate now to examine the changing patterns of Science and Technology (S&T)manpower growth to find out the ground truth reality. The present study pertains to the analysis ofS&T outturn data in various fields of scientific research that can provide a base for S&T planningand policy making. These S&T indicators will be helpful in estimating future requirements, whichin turn can be useful to a great extent in science and technology policy formulation. Theseestimates and future projections are based on mathematical modelling of the data pertaining to theoutturn of highly qualified Scientific and Technical (S&T) personnel in India from differentfaculties over the period 1990-1998. From the trend analysis it is evident that research is no moreperceived as an interesting career except in the field of engineering and medicine. The findingsfurther suggest that there is a noticeable shift from basic sciences to technology.     

Radon survey in schools in north-east Italy

During the year 2000 the Regional Agency for Environmental Protection (ARPA) of Friuli Venezia Giulia together with the Pordenone Province carried out a survey to determine the radon concentration in the schools. About 900 measurements have been carried out in 300 schools located both in the mountainous and in the flat territory. Moreover, geological information was gathered. both on a regional scale and, where possible, on a small detailed scale. The purpose of this study is to consider the possibility of using all the data collected to discover some radon prone areas. The first results of this study seem to locate some radon prone areas where the cover consists of very permeable gravelly deposits.     

Thermodynamics of phase transitions in liquids in external fields

We examine the conditions of phase equilibrium and transformations in a liquid located in an inhomogeneous external potential force field. If the force acting on the mass unit depends on the phase state, then a field-induced shift in phase equilibrium arises. As a result, at the phase interface at equal temperatures, the chemical potentials of the substance of phases do not coincide, although the full chemical potential is constant over the system. As well, one of the phases is located in a state which, in the absence of field, would be metastable. Such a field-induced phase equilibrium becomes impossible when one of the phases reaches the limiting state (spinodal). In this case, the system passes jumpwise into a new disperse state. We show that the above-mentioned features of phase equilibria in liquids and external fields manifest themselves in various physical systems and processes. These are electrical explosion of conductors, electrical explosion of micropoints on a cathode surface, and destruction of the surface of dielectrics by fast multicharged ions. Electric field also fosters the formation of nuclei of the competing phase in a supersaturated vapor and facilitates boiling of liquids on inhomogeneous heated surfaces. We discuss the possibility of achieving unusual states of substances, such as deeply supercooled hydrogen and ice at room temperature under the action of external fields.     

Flow-Induced Instabilities in Pump-Turbines in China

The stability of pump-turbines is of great importance to the operation of pumped storage power (PSP) stations. Both hydraulic instabilities and operational instabilities have been reported in PSP stations in China. In order to provide a reference to the engineers and scientists working on pump-turbines, this paper summarizes the hydraulic instabilities and performance characteristics that promote the operational instabilities encountered in pump-turbine operations in China. Definitions, analytical methods, numerical and experimental studies, and main results are clarified. Precautions and countermeasures are also provided based on a literature review. The gaps between present studies and the need for engineering practice are pointed out.     

Data storage in 2000-trends in data storage technologies

Recent projections by experts in computer systems and semiconductor technology indicate that in the year 2000, personal computers will have a processing speed of 100 million instructions per second and a semiconductor RAM capacity of 1 Gbyte. To work with such a system, data storage devices will need to provide more than 10 Gbytes of capacity and a data rate of 100 Mbyte/s. The advances required by magnetic and magnetooptical disk drives to meet these requirements are examined. Plausible system configurations for achieving these goals are described. A magnetic disk drive utilizing eight 3.5-in. disks on one spindle appears to be a possible configuration. Because of a larger areal density, a magnetooptical disk drive could meet the capacity requirements with only a single 3.5-in. disk. On the other hand, achieving the 100-Mbyte/s data rate and access times comparable to those of magnetic disk systems will require some technological breakthroughs. Without these breakthroughs and assuming magnetic disk progress as expected, magnetooptical disks are expected to provide many of the functions which floppy disks provide today-transfer of programs and databases between systems and economical offline storage     

Strain Localization Kinetics in a Metal Strip in Tension

Simulation results for strain localization in a metal strip are obtained with analytical and numerical methods. The initiation of strain localization is shown to be determined by the initial nonuniformity of material properties and by loading conditions. The more uniform material properties, the higher the strain level at which localized flow starts to develop. Metal heating under adiabatic deformation (as a result of the thermal plastic strain effect) causes a decrease in a strain level at which its localization starts. The pulse current passage, accounting for its thermal effect, exerts a similar influence. __________ Translated from Problemy Prochnosti, No. 5, pp. 104 – 117, September – October, 2005.     

Improvements in medical care and technology and reductions in traffic-related fatalities in Great Britain

Great Britain has one of the lowest levels of traffic-related fatalities in the industrialized world with a current total of about 3500 fatalities per year. Large reductions have occurred over the last 20-30 years and the government has targets of achieving another 40% reduction by 2010. This paper analyzes some of the factors that have been statistically significant in helping to achieve those reductions with a focus on improvements in medical care and technology. Using a cross-sectional time-series of regional data a fixed effects negative binomial (NB) model is estimated which includes three proxies of medical care and technology changes. These are the average length of inpatient stay in the hospital, the per-capita level of National Health Service (NHS) staff, and number of people per-capita waiting for hospital treatment. All are statistically significant with the expected sign showing that improvements in medical technology have reduced total fatalities with less of an impact from changes in medical care. Other variables are also found to be significant, including the percent of elderly people in the population, per-capita expenditure on alcohol, motorway capacity, and average vehicle age. The latter shows a surprisingly unexpected effect, with more older vehicles in a region leading to fewer fatalities. Models evaluating effects on serious and slight injuries are also estimated and serve to confirm the expected effects of medical care and technology.     

Spin injection in LED's and in unipolar devices

Spin-LED's have been used as a powerful tool to demonstrate the electrical injection of spin-polarized carriers into a semiconductor. We first give a review of some of the injector strategies that have been used (oxide-based tunnel injectors, highly doped Schottky tunnel injectors and magnetic semiconductors) with focus on the obtained spin polarizations and the bias dependence of these polarizations. We then move to the electrical aspects of the contacts and show that these should not be overlooked. The oxide-based tunnel injectors suffer from a large parasitic hole current when they are used in a spin-LED, and may become incapable of injecting any electrons in an all-electrical (unipolar) injection-detection device. We discuss the origin of this effect and point out possible solutions both for III–V semiconductors and for Si.