Speciation-analysis for recycling of critical elements in aqueous waste streams

Limited availability of inorganic commodities is one of the largest challenges for a future sustainable material use as set by European Commission. Growing life standards, demand for mobility and electronic devices require more and more specialty materials. Combining this economic importance and their supply risk, a class of critical materials is defined. PGM’s include Pt, Rh, Pd, Ir, Ru and Os. They possess unique properties, making them indispensable in autocatalysts, jewelry, electrical and electronical applications and industrial catalysts. PGM prices, with Pt being the far most important, have seriously risen in the last years. REE’s comprehend 17 elements with a large chemical similarity, essential in i.a. permanent magnets and related ‘clean energy’ applications such as wind turbines, rechargeable batteries and electric vehicles. Tight export quota set by the world’s largest exporting country of REE’s, China, hardly meet this rising demand

Moral and Religious Problems and Attitudes as Expressed by Students in Seventh-day Adventist Academies in the United States and Canada

Problem. Adolescence is characterized by many problems of adjustment. Seventh-day Adventist youth cannot be expected to be immune to these problems. The purpose of the study was to ascertain the moral and religious problems and attitudes as perceived by students in Adventist academies. An attempt was also made to evaluate, from the students\u27 viewpoint, the effectiveness of the provisions made by the academies to help meet these problems. Method Nineteen hundred and twenty students were chosen by a stratified random method from all enrollees in Seventh-day Adventist academies In the United States and Canada. Students were asked to respond to the Religious Inventory for Teen-aee Youth of the Seventh-day Adventist Church, an Instrument designed by Martin In 1963, and updated and modified to meet the purposes of this study. The Inventory consists of fifty-eight statements which are designed to ascertain the problems and attitudes of students. The method of data collection guaranteed anonymity to the responding students. Data collection was done by a responsible person designated by each school principal. Ninety-two percent of the schools and 94 percent of the students in participating schools responded. The t-test, chi-square, and analysis of variance were the statistical methods used in analyzing the data. An item analysis was included for data considered to form scales. Results. Most academy students consider twenty-one items in the Inventory to be problems. However, when considered as scales, for most academy students, Inventory subdivisions are not significant as problems. Findings for the scales which measure attitudes indicate that most academy students (1) have conservative religious views, (2) desire an active religious experience, (3) are loyal to the church, and (4) want to be involved in church activities. Most academy students are dissatisfied with the amount of help that the academy and church, through faculty, staff, and teachers, are giving them with their personal problems. Most academy students are satisfied with the spiritual, ill educational* social, and recreational activities provided to meet their needs and Interests. However, their suggestions for Improvement indicate that they perceive many weaknesses In these programs. Students\u27 definitions of dishonest behavior range far beyond the stereotyped cheating, lying, stealing syndrome. Responses show great moral sensitivity. The item which encouraged students to discuss problems in their religious life which had not been mentioned in the Inventory drew excellent responses. Most students responding appear deeply concerned about their religious experiences. Responses under the main hypotheses were compared, using eight variables for each of the items separately, and four variables for the attitude scales. Variables, significant for most of the items, were: school size, school type, sex, and grade. Conclusions. Students in Adventist academies in the United States and Canada recognize that they have moral and religious problems. However, their attitudes toward religion and the church are positive. They are dissatisfied with the help with their personal problems given them by the faculty and staff. They want more understanding and a narrowing of the communication gap. Nevertheless, they would not attend a public school if given the choice. Most students are satisfied that the program of the academy and church meets their needs. However, they suggest that many improvements be made in the program. Students in the western half of the United States have more problems. Students in the eastern half and in Canada have fewer problems. Students in boarding schools and large schools have fewer problems. Students in small day schools have more problems. Boys have more problems than girls. Lower-grade students have more problems than upper-grade students. It would appear that by working at problems revealed in this study, academy faculty and staff, and youth pastors could be much more effective in their efforts to help meet the needs of the youth of the Seventh-day Adventist Church

Engine panel seals for hypersonic engine applications: High temperature leakage assessments and flow modelling

A critical mechanical system in advanced hypersonic engines is the panel-edge seal system that seals gaps between the articulating horizontal engine panels and the adjacent engine splitter walls. Significant advancements in seal technology are required to meet the extreme demands placed on the seals, including the simultaneous requirements of low leakage, conformable, high temperature, high pressure, sliding operation. In this investigation, the seal concept design and development of two new seal classes that show promise of meeting these demands will be presented. These seals include the ceramic wafer seal and the braided ceramic rope seal. Presented are key elements of leakage flow models for each of these seal types. Flow models such as these help designers to predict performance-robbing parasitic losses past the seals, and estimate purge coolant flow rates. Comparisons are made between measured and predicted leakage rates over a wide range of engine simulated temperatures and pressures, showing good agreement