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Search Results: 1 - 10 of 1302 matches for " Simeon Popov "
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Seasonal variations in the leaf surface composition of field grown grapevine plants
DANIELA I. BATOVSKA,IVA T. TODOROVA,SIMEON S. POPOV
Journal of the Serbian Chemical Society , 2009,
Abstract: The leaf surface is the first barrier of grapevine plants towards various environmental stressors causing damage in vineyards. For this reason, identification of leaf surface metabolites in grapevine and their putative role in plant–environment interactions is important for viticulture. In this study, the leaf surface components of 16 grapevine plants (Vitis vinifera) growing in an experimental vineyard were analyzed in two consecutive seasons – the summer and the autumn of 2007. Forty-eight individual metabolites typical of the cuticular plant wax were identified by gas chromatography–mass spectrometry (GC–MS). They belonged to the following groups of compounds: hydrocarbons, sterols, terpenes, free and esterified fatty acids, alcohols, aldehydes and ketones. The metabolic profiles of the summer and the autumn samples were statistically different (P < 0.05), which was mainly attributed to the specific insects present in the two seasons and to the adaptation of the grapevine to lower temperatures.
Credit Risk Management: An Examination on the Basis of Exposures with Risk Weighting in Greek Banks  [PDF]
Simeon Karafolas
Journal of Financial Risk Management (JFRM) , 2017, DOI: 10.4236/jfrm.2017.62009
Abstract: Bank’s exposure values are classified by categories on the basis of the borrower or the kind of credit. On every credit a risk weight is applied depending on the risk of the exposure value. The exposure value multiplied by risk weight determines the weighted asset of the bank. This amount determines the regulatory capital a bank needs since the total capital ratio of a bank is defined as the ratio of regulatory capital over the weighted asset. The paper examines the evolution and structure of the exposure values considering the risk weighting of the systemic Greek banks during the crisis period. Due to mergers and acquisitions, these banks cover more than 98% of the Greek banking market by the end of 2016. The paper offers an analysis on a consolidated basis but also through a comparative analysis investigates similarities and differences existing within those banks and during the crisis period. Thus the paper can conclude on the policy followed by banks during the crisis period.
GC-MS studies of the chemical composition of two inedible mushrooms of the genus Agaricus
Assya Petrova, Kalina Alipieva, Emanuela Kostadinova, Daniela Antonova, Maria Lacheva, Melania Gjosheva, Simeon Popov, Vassya Bankova
Chemistry Central Journal , 2007, DOI: 10.1186/1752-153x-1-33
Abstract: Our GC-MS studies on the volatile fractions and butanol extracts resulted in the identification of 44 and 34 compounds for A. placomyces and A. pseudopratensis, respectively, including fatty acids and their esters, amino acids, and sugar alcohols. The most abundant constituent in the volatiles and butanol were phenol and urea respectively. We also identified the presence of ergosterol and two Δ7-sterols. In addition, 5α,8α-Epidioxi-24(ξ)-methylcholesta-6,22-diene-3β-ol was isolated for the first time from both mushrooms. Our study is therefore the first report on the chemical composition of these two species.The results obtained contribute to the knowledge of the chemical composition of mushrooms belonging to the Agaricus genus, and provide some explanation for the reported mild toxicity of A. placomyces and A. pseudopratensis, a phenonomenon that can be explained by a high phenol content, similar to that found in other Xanthodermatei species.Mushrooms in the genus Agaricus have a worldwide distribution, with up to 90 species recorded in Europe. The genus includes the most economically important and commercially cultivated mushroom in the world, A. bisporus (button mushroom) as well as many other edible species [1]. Some Agaricus species are inedible, including A. placomyces and A. pseudopratensis Bohus, which are similar in appearance to certain edible species, yet are known to possess unpleasant odours and result in gastrointestinal problems if consumed [2,3]. To the best of our knowledge, there is no information available in the literature concerning the chemical composition of these two species.In this article, we report the results of the GC-MS analyses of volatile and polar compounds, in addition to the sterol fraction obtained from the fruiting bodies of A. placomyces and A. pseudopratensis. The results can help characterise the species investigated, indicate the presence of some biologically active compounds and shed light upon their reported mild toxicity.T
A comparative study on the sterol composition of some brown algae from the Black Sea
ZORNITSA GANCHEVA KAMENARSKA,STEFKA DIMITROVA DIMITROVA-KONAKLIEVA,KAMEN LJUBOMIROV STEFANOV,SIMEON SIMEONOV POPOV
Journal of the Serbian Chemical Society , 2003,
Abstract: The sterol composition of the brown algae Stilophora rhizodes (Turner) J. Agardh, Punctaria latifolia Grev. and Punctaria plantaginea (Roth.) Grev. from the Black Sea was investigated. Fifteen sterols were identified in the sterol fractions. The main ones were cholesterol and 24-methylenecholesterol. Characteristic for brown algae, fucosterol was present in low concentrations. The results obtained were compared with recent data for the sterol composition of other Black Sea brown algae. Some conclusions concerning the evolutionary position of brown algae are made.
Accountability: an essential aspect of school governance
Simeon Maile
South African Journal of Education , 2002,
Abstract: The South African education system is still in a transformation process. Old apartheid structures and governance are objects of restructuring and transformation. The transformation of the education system is carried out to promote and uphold the founding principles of the Constitution and the fundamental rights and freedoms of every person. Among the many aspects of the education system that need to be redressed is the management of schools. In this article, the highlights problems and issues emerging from democratisation of the management of schools. In particular, the problems emanating from accountability questions such as: Whose responsibility is it? What are the place, position and responsibilities of parents in school governance? What are their duties and responsibilities with regard to accountability? The attempts to identify essentials and forms of accountability within the spectrum of school governance and the focus is on the accountability of parents and the accountability of principals and teachers to the school-governing body. Comments and recommendations are stated in the final section. (South African Journal of Education: 2002 22(4): 326-331)
Legal aspects of the disclosure of HIV serostatus by educators
Simeon Maile
South African Journal of Education , 2003,
Abstract: The disclosure of HIV serostatus in education labour relations is dealt with. I argue that whilst it is important for teachers to disclose their HIV serostatus for the benefit of education and the education of the public, the environment is not conducive to disclosure. This becomes evident when those who disclose their HIV serostatus are discriminated against and even humiliated. I substantiate my arguments with data from literature and legislation. Issues dealt with include the management of disclosure in the workplace, barriers and conditions for disclosure as well as legal aspects concerning disclosure. (South African Journal of Education: 2003 23 (1): 78-83)
Retention practices in education human resources management
Simeon Maile
South African Journal of Education , 2002,
Abstract: The public education system in South Africa, particularly in public schools, faces serious problems. The review of retention practices for teachers is premised on the principles of quality management which aim at continual increase of the accountability in education human resources management. This research revealed that the tenure process applied to teachers in public schools is weak and plunges the education system to an all-time low. The use of the suggested model is a combination of business principles and public service management principles based on legal and statutory provision. An increase in customer satisfaction is necessary. The strength of the argument is the reference to law education management theories and the involvement of unions. However, it is acknowledged that review of the retention practices alone cannot be a panacea to the crisis in education. Aspects of professionalism are alluded to and the essential role of the South African Council for Educators is also considered as well as that of the Committee for Teacher Education Policy. The notion of quality requires a rigorous effort and cautious and calculated initiatives to interrogate problems and issues in education human resources management. In conclusion, recommendations and reasons are suggested why a review of retention practices is necessary. (South African Journal of Education: 2002 22(4): 332-337)
Religion and the State in Tanzania
Simeon Mesaki
Cross-Cultural Communication , 2011, DOI: 10.3968/1636
Abstract: For the first two decades of independence Tanzania enjoyed an apparently tolerant and cordial religious climate. But since the departure of the father of the nation, Julius Nyerere from active politics in 1985 deepening religious tensions and strains began to emerge not only between the state and major religions in the country but also inter and intra-religious strife became common. Since then the country has witnessed deepening state-religious tensions and inter- and intra-religious schisms and conflicts. This paper outlines the contentious relations between the two main religious faiths (Islam and Christianity) vis-à-vis the state since colonial times (German and British) to the seemingly tranquil ujamaa period and the more contentious post- liberalisation era. Key words: Tanganyika; Tanzania; German; British; Colonial; Religion; State; Relations; Christianity; Islam Resumé: Pour les deux premières décennies de l'indépendance, la Tanzanie a connu une atmosphère religieuse apparemment tolérante et chaleureuse. Mais depuis le départ du Père de la nation, Julius Nyerere des politiques actives en 1985, des tensions et des souches religieuses ont commencé à émerger. Les aggravations sont apparues entre l'Etat et les grandes religions dans le pays, et les conflits inter et intra-religieux sont devenu communs. Depuis, le pays a été témoin de l'approfondissement des tensions état-religieuses, des schismes et des conflits inter-et intra-religieux. Le présent article décrit les relations controversées entre les deux principales confessions religieuses (Islam et christianisme) vis-à-vis de l'Etat depuis l'époque coloniale (Allemagne et Angleterre) jusqu'à la période apparemment tranquille d'Ujamaa et l'ère post-coloniale la plus controversée . Mots-clés: Tanganyika; Tanzanie; Allemagne; Angleterre; Colonial; Religion; Etat; Relations; Christianisme; Islam
From the Editor-in-Chief
Simeon Oka
Thermal Science , 2010,
Abstract: The Editorial Board of the journal Thermal Science is continuing to pay great attention to the processes in internal combustion engines, both due to their environmental impact and ability to use renewable energy sources i. e. different types of biofuels. Concerning that motor vehicles contribute about 14% of the global CO2 emission, it is understandable that many research efforts are devoted to processes in internal combustion engines and use of biofuels. The number of submitted papers dealing with processes in internal combustion engines is growing from months to months, so in the journal Thermal Science also will published in 2011 one issue devoted to the same topics. Papers submitted are already in the reviewing process. Professor Dragoslava Stojiljkovi} and Professor Stojan Petrovi} as Guest editors, had again a difficult task to make appropriate choice of the papers, covering wide range of topics. I am very grateful to Guest editors for their extremely competent choice of the topics and papers. Reviewers of the papers made, also, tremendous contributions to the quality of the papers published. This time, also, as in No. 3, 2009, we asked experts in traffic engineering to give their contribution. They pointed out importance of the internal combustion engine energy efficiency, vehicle fleet operation management and logistic efficiency, and painted large scale picture of the environmental problems caused by large density traffic. We hope that this point of view will make new impulse for many new joint projects with the aim to investigate impact of the processes in internal combustion engines and logistic of motor fleet management, and organization of traffic flows, especially in large towns, on environment. Papers devoted to the thermal processes in internal combustion engines are grouped in Part one of this issue. Due to large number of papers accepted for publication, we have been forced to introduce Part two, in which are grouped selected papers dealing with problems in fluid dynamic and heat transfer of possible interest in design of the internal combustion engines.
From the Editor-in-Chief
Simeon Oka
Thermal Science , 2011,
Abstract: In the year 2011 Editorial Board of the journal Thermal Science continues with the policy to prepare special issues, Supplements, devoted to the specific, actual scientific topics. Supple ments, issued besides four regular issues per year, have double role in publishing the journal Thermal Science: from one side Supplemental issues gives possibility to present to readers most interesting topics, and from the other side it is possible to publish greater number of papers, following permanent growing interest of the researchers to publish results of their investigations in our journal. Following those ideas, Editorial Board with greatest interest accepted proposal of the organizer of the Mini-symposium on Analytical Methods for Thermal Science, Professor Ji-Huan He and Shanghai Modern Textile Institute, to pre pare special issue with selected papers presented this Symposium. More over, to devote special issue of the journal Thermal Science, to analytical methods, seems to be very challenging, in this era of numerical models and commercial CFD software, used by every researcher, even at the beginning of the professional career. The beginners in investigations think that by numerical modelling it is possible to solve every physical problem, in thermal sciences, too. After wards, they realize that it is not the case, and that other scientific tools, experiments, and analytical methods can not be avoided, and even give better and more correct physical explanation of the processes. For those reasons, my personal opinion is that this issue of the journal Thermal Science is especially important, and will present new impulse for increasing quality of the journal. Papers presented at Symposium "Analytical Methods for Thermal Science", in the frame of the 3rd International Symposium on Nonlinear Dynamics, September 25-28, 2010, Shanghai, China, and selected for this special issue, convey a strong, reliable, efficient, and promising development of thermal science. Included herein is a collection of original refereed research papers by well-established researchers in the field of nonlinear science. We hope that these papers will prove to be a timely and valuable reference for researchers in this area. Analytical approach to thermal science is challenging and promising, and is playing an even more important role in optimal design of various thermal problems. Considering this fact, selection of the papers for this special issue has the aim to show illustrating approaches to various thermal problems by various methods including fractal geometry and fractional calculus, a
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