Oxidation resistant porous material for transpiration cooled vanes

Porous metal sheet with controlled permeability was made by space winding and diffusion bonding fine wire. Two iron-chromium-aluminum alloys and three-chromium alloys were used: GE 1541 (Fe-Cr-Al-Y), H 875 (Fe-Cr-Al-Si), TD Ni Cr, DH 245 (Ni-Cr-Al-Si) and DH 242 (Ni-Cr-Si-Cb). GE 1541 and H 875 were shown in initial tests to have greater oxidation resistance than the other candidate alloys and were therefore tested more extensively. These two materials were cyclic furnace oxidation tested in air at 1800 and 2000 F for accumulated exposure times of 4, 16, 64, 100, 200, 300, 400, 500, and and 600 hours. Oxidation weight gain, permeability change and mechanical properties were determined after exposure. Metallographic examination was performed to determine effects of exposure on the porous metal and electron beam weld joints of porous sheet to IN 100 strut material. Hundred hour stress rupture life and tensile tests were performed at 1800 F. Both alloys had excellent oxidation resistance and retention of mechanical properties and appear suitable for use as transpiration cooling materials in high temperature gas turbine engines

Program for transfer research and impact studies

Research activities conducted under the program for Transfer Research and impact studies are reviewed. Programs include: Tech Brief - Technical Support Package (TSP) Program; transfer documentation; and technology transfer profiles. An analysis of user behavior patterns is made by studying questionnaires filled out by users of the Tech Brief - TSP program. The process of technology transfer is discussed in terms of improving its effectiveness

Understanding Medical and Demographic Trends with MEDDAS

The rapid growth in the availability of microcomputers, and the vast and growing pool of available medical-demographic data, together underscore the usefulness of software tools which make the analyst's job easier. MEDDAS is one in a aeries of software packages designed to aid in one or more aspects of demographic research. Although the program development was motivated by applications in standard demographic time-series, and in health and disease statistics, the program could prove useful in other applications as well

The IIASA Health Care Resource Allocation Submodel: Model Calibration for Data from Czechoslovakia

In many developed countries the problem of allocating resources within the Health Care System (HCS) is perennial. Health Care administrators are continually asking what are the consequences of changing the mix of resources. The disaggregated resource allocation model (DRAM) has been developed to assist Health Care administrators with this problem. The model simulates how the HCS in aggregate allocates limited supplies of resources between competing demands. The principal outputs of the model are the numbers of patients treated in different categories, and the modes and quotas of treatment they receive. This paper describes how parameters were estimated for DRAM for Czechoslovakian hospital in-patient care. The model was parameterized for seven patient categories (general surgery, general medicine, obstetrics and gynaecology, traumatic and orthopaedic surgery, otorhinolaryngology, paediatrics, and ophthalmology) and two resource types (hospital beds and hospital doctors). The paper ends with a description of how the model could be used to investigate the consequences of changes in the mix of hospital beds and hospital doctors for Czechoslovakian hospital in-patient care

Smoking and Lung Cancer Prevalence: Slovakian Case Study

In the first decade of this century lung cancer was an uncommon tumor. This is in sharp contrast to the late 1970s and early 1980s: -- In 1977 the World Health Organization reported that in many countries death rates were either stationary or declining in both males and females, for cancers other than lung. The USA, Australia, Austria, Canada, Japan, Mexico, Sweden, Switzerland, and others were among the affected countries. -- In 1979 the American Cancer Society reported that the overall incidence of cancer had decreased slightly in the past 25 years and that there was an increased death rate in men, which was mainly the result of lung cancer. -- In 1982 the American Cancer Society reported, "Lung cancer rates are indeed the monster of cancer statistics, causing the overall cancer death rate to increase over 18 years from 157.0 to 169.0 per 100,000 persons". Most industrialized countries have recorded similar increases of over 100% incidence in neoplasms of the lung between 1950 and 1964. As a result of intensive epidemiological research carried out in this field during the last 20 years, it is now generally accepted that cancer of the lung is a disease of modern civilization and, in large part, preventable. The incidence of lung neoplasms correlates directly with population density, urbanization, industrialization, tobacco smoking, and even with the registration of automobiles. All these facts suggest that we are facing a real epidemic of lung cancer. The counteractions of health care systems are well known but we are interested in the future development of this process and how it would affect the population in forthcoming years. How effective could preventive campaigns be, assuming different approaches? Where to concentrate preventive efforts -- in the younger or in the older part of the population? Many scientists are looking for the answers to such questions. To develop a mathematical description of processes in the population suffering from the spread of lung cancer may help answer some of these questions and forecast future development. The descriptive model, being realized on a digital computer, could be of substantial help to health care managers, specialists in epidemiology, other physicians, and even to nonphysicians with interests in this field

Electronic properties of very thin native SiO2/a-Si:H interfaces and their comparison with those prepared by both dielectric barrier discharge oxidation at atmospheric pressure and by chemical oxidation

The contribution deals with electronic properties of thin oxide/amorphous hydrogenated silicon (a-Si:H) measured by capacitance-voltage (C-V) and charge version of deep level transient spectroscopy (Q-DLTS). The interest was focused on the studies of the interface properties of very thin dielectrics formed by dielectric barrier discharge (DBD) or natively on the a-Si:H layer. These properties were compared with those of oxide layers prepared by chemical oxidation in HNO3. The DBD was used for the preparation of a very thin SiO2 layer on a-Si:H for the first time to our knowledge. Preliminary electrical measurements confirmed that a very low interface states density was detected in the case of the native oxide/a-Si:H and DBD oxide/a-Si:H

The Future of Lung Diseases: COPD Model for Slovakia

The initial explorations of bronchial tree pathology can be traced back to the early part of the nineteenth century. Laennec was the first to demonstrate the so-called "catarrh pulmonaire" and its significance to the disease, but the attention of physicians centered upon tuberculosis and pneumonia up until the 1950s. The death of more than 4000 -- mainly older -- people during a catastrophic four-day smog in London (1952) and the realization that chronic bronchitis and its complications were the fatal causes has proved the importance of studying this group of diseases. Intensive research has demonstrated the necessity for a more precise definition of the group of illnesses described under the general term chronic nonspecific lung diseases. Common efforts of specialists from all over the world have culminated in accepted definitions of chronic bronchitis, pulmonary emphysema and bronchial asthma by the World Health Organisation (WHO). Recently, a common term has been used by mostly American authors for all of these diagnostic units: chronic obstructive pulmonary disease (COPD). Numerous studies have shown an undesirable spread of COPD in the developed countries. The high and still growing prevalence of these diseases creates a burden on health-care systems, which leads to an associated growth in health care expenditures and in the number of sick-leave cases and disabled people. It is generally understood that the causes of COPD are largely from within the society itself: life style (smoking), environmental (air) pollution, working conditions, and social and economic circumstances are believed to be responsible for the onsets of these chronic diseases. The growth in COPD prevalence is influenced by recent demographic trends, especially population aging. The large proportion of people with these sicknesses makes a complete registration of all tine cases a practical impossibility. But COPD prevalence must be estimated in some way because of the necessity to forecaste and plan appropriate health care resources. We have developed an appropriate tool for the analysis of possible trends and describe COPD model in this paper. The authors hope that it will be of some help in answering specific questions about COPD development. The model uses data from the Slovak Socialist Republic and allows the user to test several scenarios

Modeling of Public Health: Call for Interdisciplinary Actions

Health care systems today confront a range of diseases for which preventive measures lie outside traditional therapeutic medicine. The variety and multicausality of illness forms are closely related to the differences among people, especially social, economical and other conditions of their lives. The activities of many institutions which are not directly involved in health regulation, influence public health today. These facts apply also to the scale of possible control actions. Joint effects of population heterogeneity and the hierarchical nature of public health regulation seem to have led naturally to the current mix of problems and also seem to indicate that only more holistic approaches will improve the situation. One of the problems, how to overcome interdisciplinary barriers and organize effective preventive measures, may be solved only by joined efforts of social and economical institutions directly or indirectly responsible for the modern pattern of diseases. Workshops with computer modeling seem to be an appropriate instrument for developing interdisciplinary collaboration. The results of an experiment with the Slovakian Ministry of Health suggest that intensive modeling workshops involving health care planners, physicians, and other experts lead to better problem formulation and policy analysis

Program for transfer research and impact studies

Research activities conducted under the Program for Transfer Research and Impact Studies (TRIS) during 1972 included: (1) preparation of 10,196 TSP requests for TRIS application analysis; (2) interviews with over 500 individuals concerning the technical, economic, and social impacts of NASA-generated technology; (3) preparation of 38 new technology transfer example files and 101 new transfer cases; and (4) maintenance of a technology transfer library containing more than 2,900 titles. Six different modes of technology utilization are used to illustrate the pervasiveness of the transfer and diffusion of aerospace innovations. These modes also provide a basis for distinguishing the unique characteristics of the NASA Technology Utilization Program. An examination is reported of the ways in which NASA-generated technology is contributing to beneficial social change in five major areas of human concern: health, environment, safety, transportation, and communication

Managing Potential Laboratory Exposure to Ebola Virus by Using a Patient Biocontainment Care Unit1

One-sentence summary for table of contents: Recommendations are needed for management of potential laboratory exposure to a Biosafety Level 4 pathogen