1,192 research outputs found

    Studies on questions of design and construction of chain scraper conveyors

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    The basic behavior of mining crushed goods in chain scraper conveyors was examined using a special test stand. The characteristics resistance lines of the upper end-piece were determined for conveyor idle as a function of the determinative crushed good characteristics (granular structure, moisture content, type of goods) on the size of the conveyor load, on the conveyor construction and on the stopped time of the conveyor. Crushed goods with a narrow granular profile and sphere-like grains caused about 35% greater resistance than fine coal and raw coal with broad granular profile. For goods containing water more than 10% by weight, the solids friction retreated in favor of flow friction. The coefficient of resistance decreased considerably in the range of lower speeds and then increased with increasing conveyor speed. The conveyance of sandstone ore required about 280% greater specific drive than the conveyance of raw coal. Resistance coefficients for coal and raw coal showed no dependence on the design of the conveyor. Start-up of loaded conveyors after longer stop times was simulated and the specific break-loose force was determined

    The Enlargement of European Union and Labor Market: Trends and Challenges

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    In this paper the relationship between the EU labor markets and Eastern Enlargement is examined. Several issues will be examined throughout the paper, namely the current challenges and problems of the EU labor markets, their impacts on the overall competitiveness of the European economy, and the possible effects of the Eastern enlargement on both of these

    Comparison of Friedrich Holderlin and John Keats in their respective backgrounds with emphasis on the differences between their two countries

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    There are, as my Bibliography shows, many works on Hölderlin and Keats considered individually, so that any new work that claims, like the present thesis, to be independent, needs some. justification.The questions arise: Is there any sense in comparing these two poets? What is the essence of Hölderlin and the essence of Keats?It may be simply stated that both John Keats and Friedrich Hölderlin were great poets. The first glimpse we take of them shows us two, men living and writing at about the same time, often on similar themes; both with an actual poetic life of a very few years, both with personal histories of a sad and tragic nature. Sharing in some of the characteristics of the Romantic age, they were not necessarily wholly Romantic themselves. Both claimed for themselves the right to challenge authority, and as original genĂșpses to strike out on a path for themselves.My task is to explain and compare the characteristic individualities of these poets, by considering their respective backgrounds. The literature of the past, I think, we can only truly understand, if we can relate it to the history, not only of the political movements, but also of the religious, philosophical and scientific movements of the time.The particular purpose of this investigation is to ascertain and bring out the differences between Germany and England at that period, and to consider how these two poets, with certain basic similarities in temperament and gifts, developed differently in their different environments. The individualistic point of view lays emphasis on the importance of self- realisation; on the other hand, the environmental point of view makes primary and fundamental questions such as the value of knowledge or social duties and responsibilities. By 'environment' I imply more than "surroundings which compass an individual", namely, the "specific continuity of the surroundings with his own active tendencies."Both poets have seen most deeply into the meaning of Nature; both brought to their study and the individual interpretation peculiar to each, the supreme qualities of close and loving observation and sympathy. And both poets 'resemble each other in the determination which their genius gave to these qualities.Both poets were deeply conscious that poetry was their mission; it is revealed in their writings, and we have their own words for it too. Poetry as Hölderlin saw it was entrusted with the mission of revealing to a community the gods it should serve. Poetry sums up the circumstances in which a people comes into communion with its gods and in such poetry finds its higher life expressed and realised at one and the same time. Keats's conviction of the poet's office is to be the voice of one proclaiming a message, making clear a vision, transmuting into the words of a less esoteric language the conception and enunciation of a high truth, so that it may be "understanded of the people ". The function of the poet is to draw away the veils that obscure the splendours of Nature, and reveal their true and intrinsic beauty to man, so that in poetry he may find comfort to soothe him when laden with cares, and raise his thoughts above everyday life.In Part I it is the differences between the two backgrounds, especially in so far as they arise from deep -seated differences between the two countries and peoples, on which particular stress is laid. It may be a fact, as Dr. Johnson says, that "Nobody can write the life of a man but those who have eat and drunk and lived in social intercourse with him." Unfortunately such a requirement cannot now be fulfilled in the case of Hölderlin and Keats, but we can at least get to know much that was said and done by those who did come into close personal contact with them. So, too, we can contemplate their external circumstances of every kind and so form some idea of the effects these may have had on what they wrote.During my preparations it became clear to me that such an attempt requires more to carry it through than the sharp clearness of critical reasoning. That is necessary. But it is more necessary to have a psychological and emotional sympathy.In Part II, therefore, I have endeavoured in this way to trace the growth and development of the soul from its initial stages, with the influences which have been brought to bear on it.I attempt to show to what degree Hölderlin and. Keats resemble each other, and how far what was most similar in them came to be differently expressed, Partly because of their backgrounds and partly because of their different psychologies

    Entfernung von Fotolacken mit DI/O3 in der Halbleiterfertigung : Prozesschemie und analytische Aspekte

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    In the production of integrated circuits (ICs), photolithography plays a key role in wafer structuring. The basic principle of photolithography is the selective processing of areas (etching, implantation, metallisation etc.) while the others are covered and therefore protected by the resist. After each process step the resist, now modified, has to be removed. In the history of semiconductor manufacturing this has been accomplished with a mixture of H2SO4 and H2O2, H2SO4 and O3 or a plasma etch. As the structure sizes decreased they reached a stage where they had to be exposed to light of shorter wavelengths for the photolithography, going from i-line (365 nm) to DUV (248 nm and 193 nm). This change in wavelength now requires new resists and therewith new stripping methods. Beside the changes in the resist the finer structures are also more sensitive to damages caused by the resist strip. Along with this the demand for cost reduction and environment-friendliness poses a big challenge for modern resist stripping. In this study ozone in deionised water (DI/O3) was the basic chemistry investigated as it is cost efficient in production and disposal as well as environment friendly. Furthermore it is a chemistry known to cause no damage to the wafers. DI/O3 has been successfully applied to strip i-line resists. The challenge now is to find ways and means to make DI/O3 strip even highly implanted DUV resists which currently can only be removed by a plasma etch. To achieve this a detailed understanding of the behaviour of ozone in DI water and the influence of factors both chemical and physical on the stripping efficiency at the different stages in the process is necessary. Along with this, methods which enable the elucidation of resist structures and the changes they undergo during the process of photolithography as well as during the ozone strip have to be developed. This will enable us to understand the mechanisms involved and hence, ideally, develop ozone-based stripping solutions customized for each resist and process step. For this purpose the ozone decomposition in DI water with and without additives was studied via UV-Vis spectroscopy. Radicals generated within the ozone decomposition were trapped and quantified, the resists were studied directly on the wafer with IR and Raman spectroscopy and stripped with DI/O3-mixtures and different setups to find optimum conditions for a complete and damage free resist strip. UV-Vis spectroscopy at 260 nm was used to study ozone decomposition and the factors, both chemical and physical, which influence it. These factors are pH, different additives at the same pH, temperature and mixing of the solution. For the radical determination trapping reactions with MeOH and DMSO both forming CH2O which is further converted to DDL as the detectable species were compared with a variation of the classical iodometric titration acting as an absolute method without the need of calibration. IR spectroscopy proved to be a suitable method for the structural characterisation of the resists and the tracking of the changes undergone during the various processing steps as well as the ozone based stripping. For the stripping with DI/O3 IR spectroscopy delivered well-defined spectra. These displayed significant peak changes which support the assumption of classical ozonolysis as the decomposition mechanism for the unimplanted resist. For the study of the resist crust originating from ion implantation IR was fundamentally unsuitable and was replaced by Raman spectroscopy and microscopy. Raman spectra showed the crust to be of a highly carbon containing structure. Regrettably, the peak assignable to the crust was too broad for the exact composition of the crust to be determined. The wavelength region of the peak corresponds to that of peaks of glassy carbon and highly ordered and conventional graphite. Such a broad peak suggests that the structure of the crust is not uniform but contains more than one carbon modification. As the purpose of all these studies is to enable or improve DI/O3 based resist stripping on unimplanted as well as high-dose implanted resists the removal efficiency of DI/O3 spiked with different additives that alter the pH was studied. For these unimplanted resists the maximum efficiency could be achieved at pH = 5 – 7. Lowering or increasing the pH beyond this range gave poor results. The stripping of highly implanted resists could be achieved only at harsh conditions with a high pH-level of 12 - 13 with a narrow process window showing no stripping at lower pHs and severe damages at higher levels. The principle application of DI/O3 stripping chemistry could be proved but the currently required process time unfortunatelly is too long for commercial application and needs further optimisation.Im Prozess der Herstellung integrierter Schaltkreise spielt die Fotolithographie eine entscheidende Rolle bei der Strukturierung der Wafer. Das Prinzip der Fotolithographie beruht dabei auf der selektiven Prozesssierung einiger Bereiche des Wafers (Ätzen, Ionenimplantation, Metallisierung usw.) wĂ€hrend andere Bereiche durch den Fotolack geschĂŒtzt werden. Dieser, nun durch die Prozesssierung modifizierte, Fotolack muß im Anschluß wieder entfernt werden. In der Geschichte der Halbleiterfertigung geschah dies mit H2SO4/H2O2, H2SO4/O3, DI/O3 oder durch Plasmaveraschung. Seitdem die StrukturgrĂ¶ĂŸe immer mehr abnimmt, werden immer kĂŒrzere BelichtungswellenlĂ€ngen benötigt, die von i-line (365 nm) bis DUV (248 nm, 193 nm) reichen. Einhergehend mit diesen kĂŒrzeren WellenlĂ€ngen ist eine zwingende VerĂ€nderung der Fotolack-Struktur und damit die Notwendigkeit neuer Techniken zur Fotolack-Entfernung. Hinzu kommt, dass diese, nun kleineren Strukturen, ihrerseits empfindlicher gegenĂŒber SchĂ€den aus dem Entfernungsprozeß sind. Als zusĂ€tzliche Herausforderung ist der dauerhafte Druck zur Kostenreduzierung sowie zur UmweltvertrĂ€glichkeit anzusehen. Diese Dissertation beschĂ€ftigt sich daher mit der Fotolack-Entfernung basierend auf ozoniertem Wasser (DI/O3), da es kostengĂŒnstig zu erzeugen und entsorgen ist, gleichzeitig umweltfreundlich und zu guter Letzt dafĂŒr bekannt die erzeugten Strukturen nicht zu beschĂ€digen. Da in der Vergangenheit DI/O3 schon erfolgreich bei i-line Lacken eingesetzt wurde, besteht nun die Herausforderung darin diese Chemie auch auf moderne und dabei vor allem hochimplantierte DUV-Lacke anzuwenden, die bisher nur mittels Plasmaveraschung entfernbar sind. Um dieses Ziel erreichen zu können, ist ein detailliertes VerstĂ€ndnis der Ozonchemie in Wasser sowie ihrer Beeinflussung durch Additive wichtig, sowohl in Bezug auf das Ozon selbst als auch den Einfluß auf dessen Lack Entfernungspotential bei verschiedenen Prozeßschritten des Lacks. Einhergehend damit bedarf es Methoden zur Untersuchung der Lackstrukturen und zur Verfolgung ihrer Änderung wĂ€hrend bestimmter Prozeßschritte sowie wĂ€hrend der Entfernung mittels DI/O3. Das Ziel ist es das Verhalten von Ozon und Lack zu verstehen, um auf diese Weise Möglichkeiten zur maßgeschneiderten Lackentfernung zu erhalten. Zu diesem Zweck wurde der Ozonzerfall mittels UV-Vis-Spektroskopie unter verschiedenen Bedingungen untersucht. Ferner wurden die, bei der Zersetzung entstehenden, Radikale chemisch abgefangen und quantifiziert. Der Fotolack selbst wurde direkt auf dem Wafer mittels IR- und Raman-Spektroskopie untersucht und zu guter Letzt dessen Entfernung mit DI/O3 und verschiedensten ZusĂ€tzen sowie Versuchsaufbauten in Angriff genommen. Die Quantifizierung der bei der Ozon-Zersetzung entstehenden Radikale wurde mit 3 Verfahren durchgefĂŒhrt. Die ersten beiden Verfahren beruhen auf chemischen abfangreaktionen der Radikale zu einem stabilen Produkt, hier in beiden FĂ€llen das CH2O. Sie unterschieden sich lediglich im Abfangreagenz, das einmal DMSO und im anderen Fall MeOH ist. In beiden FĂ€llen wird das gebildete CH2O weiter zu einem, mittels UV-Vis detektierbaren, Farbstoff (DDL) umgesetzt. Zur Kontrolle wurde eine Variante der Iodometrie verwendet, die als Absolutmethode fungiert. Alle Untersuchungen ĂŒber den relevanten pH-Bereich zeigen dabei einen Anstieg der Radikalkonzentration mit dem pH-Wert an. Die StrukturaufklĂ€rung mittels IR-Spektroskopie erweist sich fĂŒr die meisten Prozeßschritte des Photolacks als geeignet, versagt allerdings bei implantierten Lacken. Die Auswertung der Spektren weist fĂŒr den Entfernungsprozeß mittels DI/O3 auf eine klassische Ozonolyse des Aromaten in den untersuchten, nicht implantierten Polyhydroxystyrollacken (PHS) hin. Die Anwendung von Raman-Mikroskopie hat sich als geeignet zur Untersuchung der Kruste bei implantierten Lacken erwiesen. Mit ihr konnte die Kruste dem Bereich der hochvernetzten Kohlenstoffmodifikationen (verschiedene Graphitmodifikationen, glasartiger Kohlenstoff) zugeordnet werden. Eine weitere Eingrenzung war bisher nicht möglich. Als Grund kommt eine InhomogenitĂ€t der Kruste in Frage, die wahrscheinlich aus einem Gemisch der verschiedenen Modifikationen besteht. WĂ€hrend sich bei der Entfernung nicht implantierter PHS-Lacke ein neutraler bis leicht saurer pH-Bereich von 5 bis 7 als optimal erwiesen hat, bedarf es fĂŒr hochimplantierte PHS-Lacke eines deutlich basischen Niveaus mit einem bisherigen Optimum bei pH-Wert von etwas ĂŒber 12, wobei ein sehr enges Prozeßfenster zwischen 12 und 13 festgestellt wurde. pH-Werte darunter zeigte keine Reinigungswirkung, darĂŒber kam es zu SchĂ€digungen des Si-Substrats. Die prinzipielle Anwendbarkeit von DI/O3 zur Lackentfernung konnte somit zwar gezeigt werden, allerdings ist die aktuell notwendige Prozesszeit zu lang fĂŒr einen kommerziellen Einsatz und bedarf weitere Optimierung

    The Challenges to the Protection of Women Against Domestic Violence in Jimma Zone, Oromia Regional State, Ethiopia

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    Domestic violence against women is one of the scourge and pervasive violence directed against women by their; current or former husband, current or former boyfriends and other friends who has sexual relation with the women. It has numerous and devastating physical and psychological consequences for the victim. Victims of domestic violence experience both short-term and long-lasting health outcomes including death, grave physical injury, reproductive health, unwanted pregnancy, sexually transmitted diseases, depression and suicidal behavior. However, despite of its devastating consequence, its prevalence is very high and the problems are socially condoned in Ethiopia and specifically in Jimma zone. This clearly indicates that the protection of women against domestic violence in the Jimma zone has been not succeeded which manifests the existence of challenges and obstacles. Hence, the aim of this article is to identify the challenges to the protection of women against domestic violence. To this end, the Ethiopian policy and laws regarding domestic violence are analyzed, the practical commitments of law enforcement authority of Jimma zone and socio-cultural and religious of Jimma zone community are evaluated in lights of the rights to women against domestic violence. Accordingly, the research identifies different challenges to the protection of women against domestic violence in Jimma zone which includes; legal gap, practical challenges, socio-cultural, socio-economic and religious challenges dominantly. Therefore, unless, take action upon the identified challenges, the women’s human rights will continuously to be violated. Hence, lastly to this end, the researcher arrived at the set of recommendations. Keywords: Domestic violence against women, the challenges, Laws and policy, Ethiopia, Jimma Zone, Law enforcement authority, socio-cultural, legal instruments. DOI: 10.7176/JAAS/55-04 Publication date:May 31st 201

    The Problems of Legal Gap to the Protection of Women Against Domestic Violence in Ethiopia

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    Domestic violence is the most common form of violence experienced by women around the world which is directed by their intimate partner and other family members, and manifested through; physical, sexual, psychological and economic abuse. Domestic violence against women exists in countries with varying social, political, economic, and cultural structures, and its pervasiveness signifies that the problem does not originate with the pathology of an individual person. In Ethiopia, domestic violence is very prevalent throughout the country. However, building strong legal frame work is a cornerstone for the protection of women’s rights against any sexual based discrimination and violence. Accordingly, targeting at providing better protection to the rights of women, Ethiopia has attempted to undertaken significant ‘gender-sensitive’ legislative reforms after the down fall of military junta. Foremost among these laws; the 1995 FDRE constitution, the 2003 Revised Family Law[1] and the 2005 Revised Criminal Code[2] are indicative.  However, regarding the scope of coverage of laws dealing with VAW, the Ethiopian legal framework cascades dump of the internationally accepted standards. Different forms of violence against women have not be criminalized in the way of understanding the complexity nature of the violence though international standards require States to ensure that forms of violence against women are included in criminal law as criminal acts. DOI: 10.7176/JCSD/56-01 Publication date: February 29th 2020 [1] The Revised Family Code of Ethiopia, Proclamation No. 213/2000 [2] Criminal Code of the Federal Republic of Ethiopia, proclamation no. 414/200

    History of the preanalytical phase: a personal view

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    In the 70ies of the last century, ther term “preanalytical phase” was introduced in the literature. This term describes all actions and aspects of the “brain to brain circle” of the medical laboratory diagnostic procedure happening before the analytical phase. The author describes his personal experiences in the early seventies and the following history of increasing awareness of this phase as the main cause of “laboratory errors”. This includes the definitions of influence and interference factors as well as the first publications in book, internet, CD-Rom and recent App form over the past 40 years. In addition, a short summary of previous developments as prerequesits of laboratory diagnostic actions is described from the middle age matula for urine collection to the blood collection tubes, anticoagulants and centrifuges. The short review gives a personal view on the possible causes of missing awareness of preanalytical causes of error and future aspects of new techniques in regulation of requests to introduction of quality assurance programs for preanalytical factors

    Sentiment Analysis and Ratings of Professors: A Comparison of Rate-My-Professor and Department Results

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    Previous studies employing numeric scores have observed that anonymous postings on the Rate-My-Professor (RMP) site tend to be more negative than ratings within a school. In this study, rather than using numeric evaluations, we compared the official UNIV evaluations with the RMP evaluations at the individual faculty course level, employing sentiment analysis on the text comments in evaluations. We compared positive sentiments in ratings on RMP to those in a specific business school department at a university. Our results show a statistically significant difference, with higher positive ratings at the university. We also analyzed emotions using NRC, finding a significant difference, with RMP having higher levels of negative emotions

    Online And Paper Course Evaluations

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    The purpose of this study is to compare the results of paper and online evaluations. The following analysis examines data from six departments of the School of Business Administration during a programmed switch from paper to online evaluations. The courses that participated in this study were divided and compared in the following manner: advanced and core classes, large and small sections, and courses taught by full-time and part-time faculty. The data was collected over a one-year period and contrasts the Spring 2008 and 2009 semesters, during which a total of 4,424 evaluations were reviewed.  In addition, data on the years from 2005 to 2008 are provided as a comparison benchmark of typical responses collected when paper evaluations were used. The conclusions of this study show that while a drop in response rate did occur when the switch was made, no significant change in instructor and course ratings was observed. Furthermore, the students who did complete online evaluations provided lengthier and more numerous comments
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