Soviet Population Policy

The purpose of this paper is to investigate recent Soviet responses to perceived population problems within the USSR. Such responses can, in effect, be construed as official Soviet population policy, whether identified as such by the Soviet government or not. The demographic problems to which these responses or policy decisions are aimed are divided into two broad categories: 1) the national or aggregate problems, and 2) spatial or regional problems. These population problems have become acute, particularly the regional problems, and the debate and discussion in the scholarly journals, the press, and other media indicate that population policies are undergoing close scrutiny with a view to reformulation. This paper, then, is divided into three parts: 1) a brief discussion of the definition of population policy and its interpretation in the Soviet context; 2) a review of recent population trends and resultant problems in the Soviet Union; and, finally, 3) an identification of the major policy instruments currently in force to ameliorate or solve these problems. The primary focus is, however, on this last section

High-speed data acquisition for the Princeton University Dynamic Model Track

Real time analysis of data can reduce the time involved in exploring dynamic systems. The failure of the data acquisition system at the Princeton Dynamic Model Track prompted its replacement with a real time data acquisition system. Data can be obtained from an experiment and analyzed during and immediately following a data run. The new system employs high speed analog to digital conversion and a small computer to collect data. Sampling rates of 1000 hertz over 44 channels (44,000 words/sec) are obtainable. The data can be accessed as it enters the computer's environment where it may be displayed or stored for later processing. The system was tested on a helicopter rotor steep descent experiment. The data collected compares with previous data from a similar experiment

Thermal Insulation System Analysis Tool (TISTool) User's Manual. Version 1.0.0

The Thermal Insulation System Analysis Tool (TISTool) was developed starting in 2004 by Jonathan Demko and James Fesmire. The first edition was written in Excel and Visual BasIc as macros. It included the basic shapes such as a flat plate, cylinder, dished head, and sphere. The data was from several KSC tests that were already in the public literature realm as well as data from NIST and other highly respectable sources. More recently, the tool has been updated with more test data from the Cryogenics Test Laboratory and the tank shape was added. Additionally, the tool was converted to FORTRAN 95 to allow for easier distribution of the material and tool. This document reviews the user instructions for the operation of this system

Influence technical and technological factors on efficiency combine harvesters

Found that scientists were ignored research efficiency technical features inherent in design combines, including: engine load, bandwidth, energy performance and their effect on the mechanical losses grain combine. Established that indicators of physical, parametric reliability, productivity medley, agrobiological condition affecting the grain weight heavily on the capacity of the combine and, accordingly, its performance and loss of grain on the threshing-separating device.Analytical dependence speed of the combine in comfield of loading and parametric engine reliability, systems and mechanisms of the machine. Developed an integrated method for determining the capacity and the influence of non-uniformity and yield fluctuations in area fields on it. Dependence performance combine harvester on the relative values of mechanical losses in threshing-separating device. Determined significance mechanical losses of grain on efficiency.Встановлено, що поза увагою науковців залишилися дослідження ефективності використання технічних характеристик закладених в конструкції комбайнів, зокрема: завантаження двигуна, пропускної здатності, енергетичних показників та їх вплив на величину механічних втрат зерна за комбайном. Встановлено, що показники фізичної, параметричної надійності, строкатості урожайності, агробіологічного стану хлібної маси впливають в значній мірі на пропускну здатність комбайна і, відповідно, на його продуктивність і на втрати зерна на молотильно-сепаруючим пристроєм.Аналітично визначено залежність швидкості руху комбайна в загінці від завантаження і параметричної надійності двигуна, систем і механізмів машини. Розроблено інтегральний метод визначення пропускної здатності та  досліджено вплив нерівномірності і флуктуації урожайності за площею поля на неї. Залежність продуктивності зернозбирального комбайна від відносних значень механічних втрат за  молотильно-сепаруючим пристроєм. Визначена значимість механічних втрат зерна на ефективність використання

Sage Simulation Model for Technology Demonstration Convertor by a Step-by-Step Approach

The development of a Stirling model using the 1-D Saga design code was completed using a step-by-step approach. This is a method of gradually increasing the complexity of the Saga model while observing the energy balance and energy losses at each step of the development. This step-by-step model development and energy-flow analysis can clarify where the losses occur, their impact, and suggest possible opportunities for design improvement

New Active Optical Technique Developed for Measuring Low-Earth-Orbit Atomic Oxygen Erosion of Polymers

Polymers such as polyimide Kapton (DuPont) and Teflon FEP (DuPont, fluorinated ethylene propylene) are commonly used spacecraft materials because of desirable properties such as flexibility, low density, and in the case of FEP, a low solar absorptance and high thermal emittance. Polymers on the exterior of spacecraft in the low-Earth-orbit (LEO) environment are exposed to energetic atomic oxygen. Atomic oxygen reaction with polymers causes erosion, which is a threat to spacecraft performance and durability. It is, therefore, important to understand the atomic oxygen erosion yield E (the volume loss per incident oxygen atom) of polymers being considered in spacecraft design. The most common technique for determining E is a passive technique based on mass-loss measurements of samples exposed to LEO atomic oxygen during a space flight experiment. There are certain disadvantages to this technique. First, because it is passive, data are not obtained until after the flight is completed. Also, obtaining the preflight and postflight mass measurements is complicated by the fact that many polymers absorb water and, therefore, the mass change due to water absorption can affect the E data. This is particularly true for experiments that receive low atomic oxygen exposures or for samples that have a very low E. An active atomic oxygen erosion technique based on optical measurements has been developed that has certain advantages over the mass-loss technique. This in situ technique can simultaneously provide the erosion yield data on orbit and the atomic oxygen exposure fluence, which is needed for erosion yield determination. In the optical technique, either sunlight or artificial light can be used to measure the erosion of semitransparent or opaque polymers as a result of atomic oxygen attack. The technique is simple and adaptable to a rather wide range of polymers, providing that they have a sufficiently high optical absorption coefficient. If one covers a photodiode with a uniformly thick sheet of semitransparent polymer such as Kapton H polyimide, then as atomic oxygen erodes the polymer, the short-circuit current from the photodiode will increase in an exponential manner with fluence. This nonlinear response with fluence results in a lack of sensitivity for measuring low atomic oxygen fluences. However, if one uses a variable-thickness polymer or carbon sample, which is configured as shown in the preceding figure, then a linear response can be achieved for opaque materials using a parabolic well for a circular geometry detector or a V-shaped well for a rectangular-geometry detector. Variable-thickness samples can be fabricated using many thin polymer layers. For semitransparent polymers such as Kapton H polyimide, there is an initial short-circuit current that is greater than zero. This current has a slightly nonlinear dependence on atomic oxygen fluence in comparison to opaque materials such as black Kapton as shown in the graph. For this graph figure, the total thickness of Kapton H was assumed to be 0.03 cm. The photodiode short-circuit current shown in the graph was generated on the basis of preliminary measurements-a total reflectance rho of 0.0424 and an optical absorption coefficient a of 146.5 cm(sup -1). In addition to obtaining on-orbit data, the advantage of this active erosion and erosion yield measurement technique is its simplicity and reliance upon well-characterized fluence witness materials as well as a nearly linear photodiode short-circuit current dependence upon atomic oxygen fluence. The optical technique is useful for measuring either atomic oxygen fluence or erosion, depending on the information desired. To measure the atomic oxygen erosion yield of a test material, one would need to have two photodiode sensors, one for the test material and one that uses a known erosion yield material (such as Kapton) to measure the atomic oxygen fluence

Thermal Performance Testing of Order Dependancy of Aerogels Multilayered Insulation

Robust multilayer insulation systems have long been a goal of many research projects. Such insulation systems must provide some degree of structural support and also mechanical integrity during loss of vacuum scenarios while continuing to provide insulative value to the vessel. Aerogel composite blankets can be the best insulation materials in ambient pressure environments; in high vacuum, the thermal performance of aerogel improves by about one order of magnitude. Standard multilayer insulation (MU) is typically 50% worse at ambient pressure and at soft vacuum, but as much as two or three orders of magnitude better at high vacuum. Different combinations of aerogel and multilayer insulation systems have been tested at Cryogenics Test Laboratory of NASA Kennedy Space Center. Analysis performed at Oak Ridge National Laboratory showed an importance to the relative location of the MU and aerogel blankets. Apparent thermal conductivity testing under cryogenic-vacuum conditions was performed to verify the analytical conclusion. Tests results are shown to be in agreement with the analysis which indicated that the best performance is obtained with aerogel layers located in the middle of the blanket insulation system

Communications Biophysics

Contains reports on four research projects.National Institutes of Health (Grant 1 P01 GM-14940-01)Joint Services Electronics Programs (U.S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E)National Aeronautics and Space Administration (Grant NsG-496)National Institutes of Health (Grant 1 TO1 GM-01555-01