bluuebunny/crossref_metadata_2025 huggingface dataset:
Um modelo para o compartilhamento de conhecimento no trabalho
Authors: Tonet Helena Correa , Paz Maria das Graças Torres da
Published: November 2008

O artigo focaliza o compartilhamento de conhecimento no trabalho, que é de suma importância para as organizações, mas de difícil concretização; pretende suprir uma lacuna percebida na literatura, que trata o tema de forma ampla, considerando o processo de transferência de conhecimento na organização; no modelo aqui proposto, o foco principal é o compartilhamento que ocorre nos grupos de trabalho, sendo a organização considerada como elemento do contexto em que esses grupos estão inseridos. Descreve o compartilhamento de conhecimento como processo integrado por 4 fases, iniciação, implementação, apoio e incorporação. Relaciona a cada fase situações pessoais e organizacionais que poderão ocorrer e interferir no compartilhamento, e oferece orientações para ajudar a refletir sobre os elementos fonte, destinatário, o conhecimento em si, e o contexto, que integram o processo de compartilhamento de conhecimento entre pessoas. A proposta do modelo está ancorada na Teoria de Sistemas (Bertalanffy, 1975) e em teorias da comunicação humana (Berlo, 1970; Thayer, 1979; Thompson, 1973).
Um estudo sobre a influência de Accruals na correlação entre o lucro contábil e a variação do capital circulante líquido de empresas
Authors: Colauto Romualdo Douglas , Beuren Ilse Maria
Published: November 2008

A presença de accruals são comuns no modelo contábil. Usados no sentido de provisões e estimativas, representam os elementos do resultado que, embora pelo regime de caixa já tenham sido efetivados, ainda não se atribuem na apuração ou do regime de competência. O fornecimento de uma medida do lucro para indicar o desempenho da empresa faz-se necessário para balizar o processo de tomada de decisões. Nessa perspectiva, o estudo delineado exploratório, com abordagem quantitativa, buscou analisar a influência dos accruals, provenientesda depreciação,na correlação entre o lucro contábil e a variação do capital circulante líquido. A população alvo para o estudo foram as empresas consideradas as 500 Maiores e Melhores Empresas do Brasil, conforme pesquisa realizada pela Revista Exame em 2002. Considerando-se, primeiro, uma amostra de 50 empresas selecionadas por acessibilidade, selecionaram-se intencionalmente 30 empresas para coleta e análise dos dados. Os resultados da pesquisa mostraram que houve baixa correlação negativa, quando a depreciação é reduzida do lucro contábil e baixa correlação positiva pela reintegração da depreciação ao resultado residual, significando que o desconhecimento do processo contábil pode influenciar as decisões, quando se considera o lucro como medida para determinar a eficiência empresarial.
O primeiro estruturalismo: método de pesquisa para as ciências da gestão
Authors: Thiry-Cherques Hermano Roberto
Published: November 2008

O objetivo deste texto é o exame das idéias centrais que conformam o estruturalismo como abordagem metodológica às ciências sociais e, em especial às ciências da gestão. Nele discutimos as definições básicas dos conceitos que orientaram o desenvolvimento do estruturalismo original e procuramos explicitar os passos essenciais na aplicação do método estruturalista às pesquisas em ciências da gestão. Concluímos com uma análise das críticas à abordagem estruturalista.
Perdigão: o processo decisório estratégico no investimento em tecnologia da informação
Authors: Bataglia Walter , Hirosawa Adhemar Hisashi
Published: November 2008

Em 1995, após a mudança do controle acionário da Perdigão, o novo Conselho de Administração estabeleceu como posicionamento estratégico da organização sua inserção no mercado global de carnes. Assim que foi estabelecido o objetivo estratégico de aumento de 50% da capacidade produtiva e de 60% do faturamento para o período 1995-1998, o Comitê Diretivo da empresa passou a considerar quais ações poderiam ser tomadas para assegurar a estratégia de crescimento. Garantir a otimização e a integração dos processos e do sistema de informação organizacional parecia um dos caminhos lógicos a ser seguido. No entanto o processo decisório, envolvendo o diagnóstico da situação existente, o desenvolvimento e escolha de alternativas para melhoria e a gestão do risco associado às suas implantações, exigiam a consideração e avaliação de fatores diversos.
Intraoperative ultrasonography of liver, bile ducts and pancreas
Authors: Cerri Luciana Mendes de Oliveira , Cerri Giovanni Guido
Published: November 2008

The use of intraoperative ultrasonography (IOUS) to evaluate liver, bile ducts and pancreatic disease, as compared to the results of preoperative ultrasonography and CT, is discussed. Forty-two patients who underwent abdominal surgery for suspected hepatobiliary and/or pancreatic disease were studied. The intraoperative study was carried out with a portable apparatus (Aloka 500, Japan), using 5.0 MHz and 7.5 MHz linear sterile transducers. The main indications for IOUS were the search for and/or evaluation of primary hepatic masses,hepatic abscesses or metastases, obstructive jaundice, or neuroendocrine tumors. In 15 cases (38.5 percent) from the hepatobiliary group and in 7 cases (58.3 percent) from the pancreatic group, a difference between preoperative and intraoperative findings was observed. The main difference was observed in relation to the number and size of hepatic and pancreatic lesions. The relationship between the lesions and the vascular structures was evaluated through IOUS. The method was also used to guide surgical procedures such as biopsies, the alcoholization of nodules, and the drainage of abscesses. IOUS plays an important role in detecting small hepatic and pancreatic nodules, in the assessment of anatomical relationships between the lesions and the vascular structures, and in the performance of interventionist procedures.
The Sexuality Project (Pro-Sex) of the Institute of Psychiatry of the HCFMUSP: first year of activities
Authors: Oliveira Sérgio Ricardo Campanella de , Abdo Carmita Helena Najjar
Published: November 2008

The results of one year of activities of a multidisciplinary staff comprised of five psychiatrists, one urologist, one gynecologist, and seven psychologists, who integrate the Sexuality Project (PRO-SEX) of the Institute of Psychiatric, Hospital das Clínicas, College of Medicine, University of São Paulo (FMUSP), are presented. Different sexual disorders were evaluated and treated in 140 patients (116 men and 24 women). In addition, a standard protocol was established for the medical assistance of patients; four research projects have been initiated; and courses were offered to residents in psychiatry, urology, and obstetrics-gynecology, as well as to undergraduate and postgraduate students of FMUSP.The PRO-SEX staff presented their research at one congress and two symposiums, and published four articles. Furthermore, an extensive program was established for 1995 in order to continue the advanced medical study of human sexuality.
Nasal septal pediculate carcinoma in situ: differential diagnosis
Authors: Lourenço Edmir Américo , Costa Luís Henrique Chechinato
Published: November 2008

Pediculated lesions of the nasal cavities are relatively common in daily practice, and include inflammatory polyps, benign tumors (papillomas being the most common), malignant tumors, and specific processes, such as polypoid rhinosporidiosis. The authors describe a female patient with a warty, pediculated, and asymptomatic lesion in the nasal septal mucosa. The anatomo-pathological exam showed this to be a"carcinoma in situ." The few bibliographic citations report only an association between the tumor and contact with wood dust, such as oak, ebony and beech. The patient was not exposed to these elements. It is important to emphasize the routine performance of a complete otolaryngological exam for patients seeking out specialists, in order to detect potentially malignant lesions whose early removal would permit a complete cure.
Polycystic ovary syndrome: clinical and laboratory evaluation
Authors: Khoury Marcos Yorghi , Baracat Edmund Chada , Pardini Dolores Perovano , Haidar Mauro Abi , Motta Eduardo Leme Alves da , Lima Geraldo Rodrigues de
Published: November 2008

OBJECTIVE: To evaluate clinically, and with laboratory, tests, women with polycystic ovary syndrome (PCO). PATIENTS: One hundred and twelve women with PCO were studied. METHODS: The following data was recorded: Current age; age at menarche; menstrual irregularity, occurrence of similar cases in the family; fertility, obstetric history; body mass index (BMI); and presence of hirsutism. Serum measurements of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin, free testosterone, and dehydroepiandrosterone sulfate were taken. RESULTS: All patients presented either oligomenorrhea (31 percent), periods of secondary amenorrhea (9 percent), or both alterations (60 percent). The majority of the patients were infertile (75.6 percent). The LH/FSH ratio was higher than 2:1 in 55 percent of the patients and higher than 3:1 in 26.2 percent. The ultrasonographic aspect of the ovaries was considered to be normal in 31 percent. CONCLUSION: The main clinical feature of the PCO is the irregularity of menses since menarche, and that the laboratory tests would be important to exclude other disorders such as hyperprolactinemia or hyperandrogenemia caused by late-onset congenital adrenal hyperplasia.
Cross- cultural validation of the Brazilian Portuguese version of the Social Phobia Inventory (SPIN): study of the items and internal consistency
Authors: Osório Flávia de Lima , Crippa José Alexandre S. , Loureiro Sonia Regina
Published: November 2008

OBJECTIVE: The objective of the present study was to carry out the cross- cultural validation for Brazilian Portuguese of the Social Phobia Inventory, an instrument for the evaluation of fear, avoidance and physiological symptoms associated with social anxiety disorder. METHOD: The process of translation and adaptation involved four bilingual professionals, appreciation and approval of the back- translation by the authors of the original scale, a pilot study with 30 Brazilian university students, and appreciation by raters who confirmed the face validity of the Portuguese version, which was named " Inventário de Fobia Social" . As part of the psychometric study of the Social Phobia Inventory, analysis of the items and evaluation of the internal consistency of the instrument were performed in a study conducted on 2314 university students. RESULTS: The results demonstrated that item 11, related to the fear of public speaking, was the most frequently scored item. The correlation of the items with the total score was quite adequate, ranging from 0.44 to 0.71, as was the internal consistency, which ranged from 0.71 to 0.90. DISCUSSION/CONCLUSION: The authors conclude that the Brazilian Portuguese version of the Social Phobia Inventory proved to be adequate regarding the psychometric properties initially studied, with qualities quite close to those of the original study. Studies that will evaluate the remaining indicators of validity of the Social Phobia Inventory in clinical and non-clinical samples are considered to be opportune and necessary.
Computational form-finding methods for fabric structures
Authors: Lewis W. J.
Published: November 2008

Form-finding is a process that determines the surface configuration of a fabric structure under prestress. This process can be carried out using a variety of numerical methods, of which the most common are (a) transient stiffness, (b) force density, and (c) dynamic relaxation. The paper describes the three methods, discusses their advantages and limitations, and provides insights into their applicability as numerical tools for the design of fabric structures. Further, it describes various approaches to surface discretisation, and discusses consequences of using ‘mesh control’ and elastic effects in the design of form-found surfaces. A brief discussion of the general recommendations given in the European design guide for tensile surfaces structures concludes the paper.
European urban policies and the neighbourhood: an overview
Authors: Atkinson R.
Published: November 2008

This paper provides an overview of the ‘urban policies’ developed to address urban problems in a number of different European countries. Although a ‘conventional wisdom’ has developed about how to address such problems, each country has developed its own particular approach. The paper first of all provides a brief overview of the situation at the European level. The main focus of the paper, however, is on neighbourhood-based policies in Denmark, England, France, and Germany. This illustrates the broadly similar, albeit at times distinctive, approaches each country has developed particularly with regard to the neighbourhood. Finally the paper briefly considers some wider governance issues raised by these neighbourhood-based programmes. The conclusion then identifies and reflects on common themes, conceptualisations and approaches.
Briefing: Community resilience to extreme weather
Authors: Goodier Chris I. , Wood Gavin A. , Shao Li
Published: November 2008

The global climate is changing in ways that are likely to have a significant impact on society and the natural and built environments over the coming decades. Extreme weather events, both globally and in the UK, appear to be increasing in frequency and severity, and there is growing concern that the cost of managing them and their impacts will increase. Preparedness and resilience measures can help to mitigate impacts and associated costs to both infrastructure and to people. A new multi-institutional research programme involving 13 universities in the UK called Crew (community resilience to extreme weather) has recently started, which will develop a tool kit to support decision making and will therefore improve the capacity for resilience of local communities to the impacts of future extreme weather. The broad aim is to develop a set of web-based tools for mapping potential future extreme weather events, for assessing their impacts under a range of scenarios, and to evaluate and offer a range of potential coping measures. As part of this the project will identify existing coping measures for dealing with extreme weather events at the levels of the community, buildings and individuals. The work will assess coping measures in terms of their suitability for the climate and buildings in the UK, their effectiveness for risk reduction and technical aspects that may affect their uptake. This will therefore provide the basis for the development of more effective coping measures for the community, including households, small businesses and local policy makers.
Critical Evaluations of Additives Used in Shale Slickwater Fracs
Authors: Kaufman P. , Penny G. S. , Paktinat J.
Published: November 2008

Slickwater fracturing has increased over the past decade with the advent of shale gas plays. Horizontal wells are now the standard with up to 1 million gallons of water in as many as 6 to 9 frac stages per well. The objective is to create as much contact with the reservoir as possible and many times a secondary goal is to prop open the created fractures. Additive packages have been minimized to save money. Due to environmental concerns and fresh water availability, the flowback and produced water is collected and used for subsequent fracture treatments. The purpose of this work is to examine water treatment techniques and critically evaluate the performance of additives that are employed in slickwater fracs of shale reservoirs and give guidelines for selecting additives that will optimize performance during pumping, fluid recovery and production. Comments will be made on the topic of proppant selection. Following the proppant, the major additive in most jobs will be the friction reducer which is required to reduce the friction pressure while pumping at the extreme rates of 50 to 120 barrels per minute (bpm). The second concern should be additives to treat bacteriological activity. The injection of water will ultimately result in the cultivation of sulfate reducing bacteria which produce Hydrogen sulfide (H2S) and biproducts such as black iron sulfide on the surface if not treated properly. Scale inhibitors become vitally important as water dissolves salts from the formation. Shales have sub microDarcy matrix permeability with natural fractures and cleats providing avenues for gas desorption and flow to the wellbore. Shales can have as much as 50% clays. Are additives necessary to stabilize clays? Finally, the use of surfactants can be beneficial in promoting the flowback of injected fluids to restore the relative permeability to gas. Which surfactant types are the most beneficial?
Bond Strength of Gold Alloys Laser Welded to Cobalt-Chromium Alloy
Authors: Watanabe Ikuya , Wallace Cameron
Published: November 2008

The objective of this study was to investigate the joint properties between cast gold alloys and Co-Cr alloy laser-welded by Nd:YAG laser. Cast plates were fabricated from three types of gold alloys (Type IV, Type II and low-gold) and a Co-Cr alloy. Each gold alloy was laser-welded to Co-Cr using a dental laser-welding machine. Homogeneously-welded and non-welded control specimens were also prepared. Tensile testing was conducted and data were statistically analyzed using ANOVA. The homogeneously-welded groups showed inferior fracture load compared to corresponding control groups, except for Co-Cr. In the specimens welded heterogeneously to Co-Cr, Type IV was the greatest, followed by low-gold and Type II. There was no statistical difference (P<0.05) in fracture load between Type II control and that welded to Co-Cr. Higher elongations were obtained for Type II in all conditions, whereas the lowest elongation occurred for low-gold welded to Co-Cr. This study indicated that, of the three gold alloys tested, the Type IV gold alloy was the most suitable alloy for laser-welding to Co-Cr.
A Probability Method for Very Short-Term Steady State Analysis of a Distribution System with Wind Farms
Authors: Bracale Antonio , Caramia Pierluigi , Carpinelli Guido , Varilone Pietro
Published: November 2008

In this paper, a probabilistic method is proposed to analyze the very short-term steady-state performance of an unbalanced distribution electrical system characterized by the presence of wind farms. This method, which can take into account the uncertainties of loads and wind productions, is based on a Monte Carlo simulation procedure applied to the non-linear three-phase load flow equations, including wind farm models. Bayesian time series models are used to predict the next hour's wind speed probability density functions, making possible a predictive evaluation of the very short-term system steady-state behavior. Numerical applications are presented and discussed with reference to the three-phase unbalanced IEEE 34-bus test distribution system in the presence of wind farms connected at different busbars.
Osmo-Convective Dehydration of Plum (Prunus salicina L)
Authors: Ibitwar B. B , Kaur Bhupinder , Arora Sadhna , Pathare Pankaj B
Published: November 2008

Plums, which have a high water content level, are highly perishable and it is necessary to find alternatives to minimize product deterioration. Osmotic dehydration is one of these effective alternatives. Besides water removal from the product, the process also promotes solid gain due to high concentration of solute. In this study, the effect of different osmotic agents (sugar and sugar-glycerol) was reported. The Magee model could satisfactorily describe the solid gain and water loss during osmosis. Drying was conducted at 45, 55 and 65°C. Osmotic dehydration followed by air drying reduces the drying period. Osmotic dehydration resulted in a decrease in total convective dehydration time. The osmotic dehydration in sugar and sugar-glycerol solution reduced approximately 240 and 120 minutes as compared to the osmo-convective dehydration time of lye-treated plums at 65°C. The drying rate curves contained no constant rate period and showed a linear falling rate throughout the drying process.
Drying Kinetics of Osmotically Pre-Treated Plum Tomato Pieces
Authors: Brooks Marianne S , Ghaly Abdel E , Abou El-Hana Nabiha H
Published: November 2008

The air-drying kinetics of plum tomato pieces pre-treated with different osmotic solutions were investigated. Four pre-treatment solutions (comprised of salt, sugar and/or calcium lactate), three sample geometries (halves, quarters and eighths) and two air-drying temperatures (55 and 65°C) were studied. In general, the rate of drying over time appeared to fit an exponential curve (R2 values between 0.74 and 0.99). A closer look at the data indicated that the rate of drying appeared to follow two separate falling rate periods. The change from one falling rate period to another was observed for samples at a transition moisture ratio of ~ 0.2, for all geometries and temperatures. Thus, modeling the process was improved by including the two falling rate periods. The drying constant (K) for the two falling rate periods ranged between 0.05 to 0.3 h-1. Moisture diffusivity values ranged from 2.5 x 10-9 to 9 x 10-9 m2 s-1 and were relatively constant during the first falling rate period. During the second falling rate period, the diffusivity increased as the moisture ratio decreased, though this change was less pronounced as the sample size decreased from halves to eighths. The untreated samples had lower diffusivities than those with osmotic pre-treatment but there were no differences amongst the various pre-treatment solutions. In general, moisture diffusivities showed a dependence on the sample size, as the larger tomato samples had higher values of diffusivity. The greater diffusivity seen in the larger samples may be due to the collapse of cell walls in the skin.
New simple algebraic root locus method for design of feedback control systems
Authors: Cingara Aleksandar
Published: November 2008

New concept of algebraic characteristic equation decomposition method is presented to simplify the design of closed-loop systems for practical applications. The method consists of two decompositions. The first one, decomposition of the characteristic equation into two lower order equations, was performed in order to simplify the analysis and design of closed loop systems. The second is the decomposition of Laplace variable, s, into two variables, damping coefficient, ?, and natural frequency, ? n. Those two decompositions reduce the design of any order feedback systems to setting of two complex dominant poles in the desired position. In the paper, we derived explicit equations for six cases: first, second and third order system with P and PI. We got the analytical solutions for the case of fourth and fifth order characteristic equations with the P and PI controller; one may obtain a complete analytical solution of controller gain as a function of the desired damping coefficient. The complete derivation is given for the third order equation with P and PI controller. We can extend the number of specified poles to the highest order of the characteristic equation working in a similar way, so we can specify the position of each pole. The concept is similar to the root locus but root locus is implicit, which makes it more complicated and this is simpler explicit root locus. Standard procedures, root locus and Bode diagrams or Nichol Charts, are neither algebraic nor explicit. We basically change controller parameters and observe the change of some function until we get the desired specifications. The derived method has three important advantage over the standard procedures. It is general, algebraic and explicit. Those are the best poles design results possible; it is not possible to get better controller design results.
Solvent effects on photodegradation of CI Reactive Orange 16 by simulated solar light
Authors: Mijin Dusan , Zlatic Dragana , Uscumlic Gordana , Jovancic Petar
Published: November 2008

Organic solvents may appear in wastewaters and other industrial waste streams containing dyes, therefore, their photodegradation catalyzed by TiO2 should be investigated. Solvent effect on photodegradation of CI Reactive Orange 16 has been studied using simulated solar light and P-25 TiO2. Methyl, ethyl and isopropyl alcohol as well as acetone were used as solvents. Photodegradation reaction was faster in methyl than in ethyl alcohol while in water was the slowest. RO16 photodegradation efficiency and reaction rate decreased in the presence of small concentration of ethanol. Higher photodegradation efficiency was observed for higher ethanol concentration. For acetone, photodegradation decreased as concentration of acetone increased. It seems that protic solvents at higher concentrations promote reaction, while at low concentrations slow down reaction. Aprotic solvents slow down reaction.
Kinetics and modeling of the extraction of flax seed oil (Linum usitatissimum L.) by supercritical carbon dioxide
Authors: Nikolovski Branislava , Sovilj Milan , Djokic Mirjana , Vidovic Senka
Published: November 2008

The object of this study is supercritical carbon dioxide extraction of flax seed oil (Linum usitatissimum L.) at the pressures of 30, 40 and 50 MPa, temperatures of 47 and 52 ?C, extraction time of 4 h, special flows of solvent of 8.8 kg/(kg h), and particle size fractions of grinding material of 0.16-0.315, 0.315-0.80 and 0.80-2.00 mm. Supercritical fluid extraction (SFE) of the flax seed oil on the laboratory scale, with the special interest in the influence of the extraction pressure, temperature, extraction time, and grinding of ground material on the overall yield of the flax seed oil was investigated. Experimental results of the oil yields were compared with the data obtained by the mathematical model of Hong et al. [I.K. Hong, S.W. Rho, K.S. Lee, K.P. Yoo, Korean J. Chem. Eng. 7 (1990) 40], presented in the literature.
Detection of the ultimate content of uranium of depleted ammunition in different materials
Authors: Islamovic Safija , Selimovic Renato
Published: November 2008

The goal of this work was to determine the ultimate detectable content of uranium arising from depleted uranium ammunition in different natural materials, namely, soil, gravel, wood by ?-spectrometry. The United Nations Environment Programme (UNEP) report has confirmed following findings: (a) it is not possible to detect uranium-containing ammunition by any available instrument in the soil deeper than 40 cm; (b) the scintillation detector MC PHAR, due to its high sensitivity (above 80 keV), is considered to be the ideal detector for low energy ?-irradiation, which is characteristic for depleted uranium.
Neutron activation of a realgar ore sample
Authors: Zovko Emira , Pujic Zdravko
Published: November 2008

The neutron activation by ?-spectrometry measurement was used to follow hydrometallurgical processes of a realgar ore sample from Vares area, Bosnia and Herzegovina. Realgar ore disintegration has been performed by dissolving in either sodium hydroxide or sodium sulphide. Realgar ore disintegration by dissolving with sodium hydroxide is not suitable for neutron activation processes. On the other hand, realgar ore disintegration by dissolving with sodium sulphide is suitable and useful for neutron activation processes. It has been found that As2O3 can be successfully separated in an amount of 85 ? 5%.
Redox regulation of cell cycle through nitric oxide
Authors: Bogdanovic Visnja , Spasic Mihajlo
Published: November 2008

This paper investigates the effects of sodium nitroprusside as NO donor on two cell lines in culture: transformed cells of mice fibroblasts (L929) and malignant cells of human eritroleukemia (K562). Low concentrations of NO have stimulative effect, while high concentrations have inhibitive effects on proliferation of K562 cells in a dose-dependent manner. In our experiments, by using sodium nitroprusside (SNP) as NO donor and two kinds of superoxide dismutase, Cu,Zn-SOD and Mn-SOD, we created conditions to generate several kinds of signal molecules and investigated reaction of transformed (L929) and malignant (K562) cells to dose. Results of experiments are showing that chosen parameters (amount of free thiol groups and glutathione) may be relevant in monitoring the effect of exogenous nitrate oxide and its redox descendants in different, both transformed and malignant cell lines.
The age of our universe
Authors: Levenspiel Octave
Published: November 2008

If we assume that the observed Redshift of starlight is due to the Doppler effect we end up with models of the universe which contradict the basic laws of science. If we assume that the red shift may be due to a tiring of light, an assumption still to be tested, we end up with no contradiction with the laws of science. You the reader must choose.
Ribofuranose as a carrier of tetraoxane and 4-aminoquinoline antimalarial pharmacophores
Authors: Opsenica Igor , Smith Kirsten , Gerena Lucia , Gaica Sandra , Solaja Bogdan
Published: November 2008

Several tetraoxane and 4-aminoquinoline molecules were prepared in order to examine the influence of ribofuranose as a carrier molecule on the antimalarial activity of test compounds. The synthesized compounds showed pronounced antimalarial activity against Plasmodium falciparum chloroquine susceptible D6, chloroquine resistant W2 and multidrug-resistant TM91C235 (Thailand) strains. The aminoquinoline derivative 4 was more active against W2 and TM91C235 strains than the control compounds (CQ and MFQ).
UV-effects on antioxidant activity of selected carotenoids in the presence of lecithin estimated by DPPH test
Authors: Cvetkovic Dragan , Markovic Dejan
Published: November 2008

The effects of ultraviolet radiation (UV) on the antioxidant action of three selected carotenoids (?-carotene, lycopene and lutein) in the presence of a lipoidal lecithin mixture were studied by the DPPH (1,1-diphenyl-2-picrylhydrazyl) test. The test is based on the measurement of the decrease of the free DPPH radical absorbance at 517 nm caused by the antioxidant action of carotenoids, which appeared to be strongly affected by UV-action. The high-energy input of the involved UV-photons plays a major governing role.
Designing, synthesis and spectral characterization of Schiff base transition metal complexes: DNA cleavage and antimicrobial activity studies
Authors: Raman N. , Ali Syed , Raja Dhaveethu
Published: November 2008

A new series of transition metal complexes of Cu(II), Ni(II), Co(II) and Zn(II) have been designed and synthesized using a Schiff base (L) derived from 4-aminoantipyrine, benzaldehyde and o-phenylenediamine. The structural features were derived from their elemental analyses, magnetic susceptibility and molar conductivity, as well as from mass, IR, UV-Vis, 1H-NMR and ESR spectral studies. The FAB mass spectral data and elemental analyses showed that the complexes had a composition of the ML type. The UV-Vis and ESR spectral data of the complexes suggested a square-planar geometry around the central metal ion. The magnetic susceptibility values of the complexes indicated that they were monomeric in nature. Antimicrobial screening tests were also performed against four bacteria, viz. Salmonella typhi, Staphylococcus aureus, Escherichia coli, and Bacillus subtilis and three fungi, viz. Aspergillus niger, Aspergillus flavus and Rhizoctonia bataicola. These data gave good results in the presence of metal ion in the ligand system. The nuclease activity of the above metal complexes shows that only the copper complex cleaves CT DNA in the presence of an oxidant.
Transition metal complexes with oxygen donor ligands: A synthesis, spectral, thermal and antimicrobial study
Authors: Patange Vaibhav , Pardeshi Rajendra , Arbad Balasaheb
Published: November 2008

Transition metal complexes of chalcones derived from the condensation of 3-acetyl-6-methyl-2H-pyran-2,4(3H)-dione (dehydroacetic acid) and p-methoxybenzaldehyde (HL1) or p-nitrobenzaldehyde (HL2) were synthesized and characterized by elemental analysis, conductometry, thermal analysis, magnetic measurements, IR, 1H-NMR, UV-Vis spectroscopy and a microbial study. From the analytical and thermal data, the stoichiometry of the complexes was found to be 1:2 (metal: ligand). The molar conductance data revealed that all the metal chelates were non-electrolytes. The thermal stability of the complexes was studied by thermogravimetry and the decomposition schemes of the complexes are given. The ligands and their metal complexes were screened for antibacterial activity against Staphylococcus aureus and Escherichia coli, and fungicidal activity against Aspergillus flavus, Curvularia lunata and Penicillium notatum.
Conductometric and pH metric investigations of the oxalic acid and NaAsO2 reaction
Authors: Obradovic Mirjana , Sunaric Slavica , Mitic Snezana , Veselinovic Dragan
Published: November 2008

The reaction between NaAsO2 and oxalic acid was studied by pH-metric and conductometric measurements, applying the methods of continual variation and pH-metric and conductometric titration. It was found that oxalic acid forms a complex anion of the type [AsOC2O4]-. The relative stability constant of the complex at ionic strengths, I, of 0.10 (log Kr = 4.70), 0.20 (log Kr=4.51), 0.50 (log Kr = 4.24) and 0 (log K 0 = 5.05) and thermodynamic parameters were calculated using the data obtained by pH-metric measurements at 25.0?0.1?C (DH = 10.5 kJ mol-1, DG = -29.0 kJ mol-1, DS = 133 J mol-1 K-1).
Optimization of the self-sufficient thorium fuel cycle for CANDU power reactors
Authors: Bergelson Boris , Gerasimov Alexander , Tikhomirov Georgy
Published: November 2008

The results of optimization calculations for CANDU reactors operating in the thorium cycle are presented in this paper. Calculations were performed to validate the feasibility of operating a heavy-water thermal neutron power reactor in a self-sufficient thorium cycle. Two modes of operation were considered in the paper: the mode of preliminary accumulation of 233U in the reactor itself and the mode of operation in a self-sufficient cycle. For the mode of accumulation of 233U, it was assumed that enriched uranium or plutonium was used as additional fissile material to provide neutrons for 233U production. In the self-sufficient mode of operation, the mass and isotopic composition of heavy nuclei unloaded from the reactor should provide (after the removal of fission products) the value of the multiplication factor of the cell in the following cycle K>1. Additionally, the task was to determine the geometry and composition of the cell for an acceptable burn up of 233U. The results obtained demonstrate that the realization of a self-sufficient thorium mode for a CANDU reactor is possible without using new technologies. The main features of the reactor ensuring a self-sufficient mode of operation are a good neutron balance and moving of fuel through the active core.
Fuel depletion calculation in MTR-LEU NUR reactor
Authors: Zeggar Foudil , Halilou Amrane , Meftah Brahim , Mokeddem Mohamed , Letaim Fathi , Bousbia-Salah Anis
Published: November 2008

In this article, we present the results of a few energy groups calculations for the NUR reactor fuel depletion analysis up to 45 000 MWd/tU taken as the maximum fuel burn up. The WIMSD-4 cell code has been employed as a calculation tool. In this study, we are interested in actinides such as the uranium and plutonium isotopes, as well as fission products Xe-135, Sm-149, Sm-151, Eu-155, and Gd-157. Calculation results regarding the five energy groups are in a good agreement with those obtained with only two energy groups which can, therefore, be used in all subsequent calculations. Calculation results presented in this article can be used as a microscopic data base for estimating the amount of radioactive sources randomly dispersed in the environment. They can also be used to monitor the fuel assemblies inventory at the core level.
Photon scattering and reflection in medical diagnostic energy domain
Authors: Ljubenov Vladan , Simovic Rodoljub , Markovic Srpko , Ilic Radovan
Published: November 2008

The dependence of reflected photons angular and energy distributions on parameter c' - the probability for large-angle scattering - is treated in this paper. The simulation of photon reflection was performed by the FOTELP code for a normal incidence of photons into infinite slabs of common shielding materials, and for the photon initial energies of 20 keV up to 100 keV.
Influence of packaging configuration with kovar lid on RADFET response to proton irradiation
Authors: Stankovic Srboljub , Ilic Radovan , Davidovic Milos , Kovacevic Milojko , Davidovic Dragomir
Published: November 2008

Radiation sensing MOSFETs (RADFETs) have found numerous applications in space research, as well as in nuclear technology and research, and radiotherapy. Since proton irradiation is an essential part of the space radiation environment, it is important to know RADFET proton response precisely. In this work a numerical simulation of RADFET proton response is performed. To this end the proton transport Monte Carlo software SRNA-2K5, developed by one of the authors, has been adapted to obtain the energy deposited in the RADFET structure and dose distribution within the microscopic dimensions of the dosimeter sensitive volume. Our results show that RADFET response to proton irradiation depends significantly of packaging configurations with kovar lid.
Influence of radiation energy and angle of incidence on the uncertainty in measurements by GM counters
Authors: Stankovic Koviljka , Vujisic Milos
Published: November 2008

This paper discusses the influence of radiation energy and angle of incidence as possible sources of uncertainties in measurements performed by GM counters. Based on the detection efficiency of GM counters, it has been concluded that the energy of incident radiation does not contribute to the overall uncertainty. The angle of incident radiation does contribute to overall uncertainty, but only in the case of gamma radiation detection. In that case, the uncertainty should be determined by using geometrical probability.
Experimental testing of the digital multichannel analyzer for gamma spectrometry measurements
Authors: Novkovic Dusan , Nadjdjerdj Laslo , Kandic Aleksandar , Vukanac Ivana , Djurasevic Mirjana
Published: November 2008

The results of experimental testing of the digital multichannel analyzer which digitalizes the signal after a preamplifier are presented. The recordings of some of the characteristics of the spectrometer containing a digital MCA, such as full-peak efficiency, net area ratio of the two peaks and the stability of the peak position, were carried out under different input counting rates, with different radioactive sources. The tested MCA has shown some excellent features, like the stability of the peak position over a long-term period and flexibility in the adjusting of optimum measurement conditions. However, the performed tests have also shown some serious and unexpected disadvantages of the digital MCA when it operates under certain circumstances, one of them having to do with the automatic tuning of live-time correction at low-input counting rates.
Complex powers of operators
Authors: Kostic Marko
Published: November 2008

We define the complex powers of a densely defined operator A whose resolvent exists in a suitable region of the complex plane. Generally, this region is strictly contained in an angle and there exists ? ? [0,?) such that the resolvent of A is bounded by O((1 + |?|)?) there. We prove that for some particular choices of a fractional number b, the negative of the fractional power (-A)b is the c.i.g. of an analytic semigroup of growth order r > 0.
Singles in a Markov chain
Authors: Omey Edward , van Gulck
Published: November 2008

Let {Xi, i _? 1} denote a sequence of variables that take values in {0, 1} and suppose that the sequence forms a Markov chain with transition matrix P and with initial distribution (q, p) = (P(X1 = 0), P(X1 = 1)). Several authors have studied the quantities Sn, Y (r) and AR(n), where Sn = ?n i=1 Xi denotes the number of successes, where Y (r) denotes the number of experiments up to the r-th success and where AR(n) denotes the number of runs. In the present paper we study the number of singles AS(n) in the vector (X1,X2, . . . , Xn). A single in a sequence is an isolated value of 0 or 1, i.e., a run of length 1. Among others we prove a central limit theorem for AS(n).
Drazin inverses of operators with rational resolvent
Authors: Schmoeger Christoph
Published: November 2008

Let A be a bounded linear operator on a Banach space such that the resolvent of A is rational. If 0 is in the spectrum of A, then it is well known that A is Drazin invertible. We investigate spectral properties of the Drazin inverse of A. For example we show that the Drazin inverse of A is a polynomial in A.
Application of the mean ergodic theorem to certain semigroups
Authors: Herzog Gerd , Schmoeger Christoph
Published: November 2008

We study the asymptotic behaviour of solutions of the Cauchy problem u' = ?n j=1(Aj + A-1 j ) - 2nI_u, u(0) = x as t??, for invertible isometries A1, . . . , An.
On the mean square of the Riemann zeta function and the divisor problem
Authors: Yang Yifan
Published: November 2008

Let ?(T) and E(T) be the error terms in the classical Dirichlet divisor problem and in the asymptotic formula for the mean square of the Riemann zeta function in the critical strip, respectively. We show that ?(T) and E(T) are asymptotic integral transforms of each other. We then use this integral representation of ?(T) to give a new proof of a result of M. Jutila.
Headache associated with hemodialysis
Authors: Nikic Petar , Zidverc-Trajkovic Jasna , Andric Branislav , Djuric Marija , Stojimirovic Biljana
Published: November 2008

INTRODUCTION Hemodialysis (HD) is one of the most accessible methods for the treatment of the growing number of patients suffering from terminal-stage renal insufficiency. Although headache is the most frequently encountered neurological symptom during HD, there are few studies reporting its prevalence and clinical features. OBJECTIVE The objective of this study was to examine the frequency, demographic and clinical features of headache during HD, and to compare these parameters among patients with and without headache. METHOD The study involved 126 patients (48 female and 78 male) with chronic renal failure on regular HD for at least six months, at the Dialysis Unit of Nephrology Department, Krusevac. All patients were inquired about their possible problems with headache using the standardized questionnaire designed according to the diagnostic criteria of the International Headache Classification of Headache Disorders, second edition, published in 2004 (ICHD-II). Subsequently, the patients were clinically evaluated and patients with headaches were further sub classified by a neurologist with special interest in headache disorders. Patients with headache were compared to the patients without headache regarding age, sex, duration of HD, causes of end-stage renal disease, arterial diastolic and systolic blood pressure, and serum values of the most important blood parameters such as sodium, potassium, urea and creatinine. In the group of patients with headache we analyzed the characteristics of specific headache type according to ICHD-II classification. We also analyzed the most important clinical features of hemodialysis headache (HDH). RESULTS In the group of 126 evaluated patients, 41 (32.5%) patients had headaches. There were no statistically significant differences between the patients with headaches and those without headaches regarding sex, age, BMI, duration of HD, causes of end-stage renal disease, arterial blood pressure, red blood cell count, serum concentration of hemoglobin, blood urea nitrogen, creatinine, glucose, MCHC, total protein, sodium and potassium. Fourteen patients (34% of those with headaches) experienced headache during the HD session and were sub classified as HDH using diagnostic criteria of the International Headache Society. Tension type headache (41% of those with headaches) and migraine without aura (10%) were most common in the primary headache group and headache due to arterial hypertension (7%) was the most prevalent among the secondary headaches. Although there were some common clinical characteristics, we could not find a unifying clinical pattern in the patients with HDH. CONCLUSION Hemodialysis headache is the most common headache in patients undergoing hemodialysis, and despite some common symptoms, it does not appear to be uniform in its clinical characteristics.
Tooth pathology analysis of osteological material from the medieval locality of Saint Pantelejmon church in Nis
Authors: Mitic Nadica , Mitic Aleksandar , Mitic Vladimir , Crnoglavac Vesna , Vlak Dejana , Nikolic Marija
Published: November 2008

INTRODUCTION Medieval necropolis at the porch of St. Panteleimon church in Nis, from 12th century represents a typical Serbian necropolis, which has its analogies in several areas in Serbia. Preservation of the skeletal remains belongs to category of good and medium preservation. OBJECTIVE The aim of the work was to study the skeletal remains for the prevalence of tooth caries, localization of caries lesions, presence of abrasion, supragingival tartar and resorption of alveolar bone as the indicator of periodontal disease. METHOD The analyses included 42 skeletal remains. The anthropological analyses involved paleopathological findings on 954 teeth of 22 men and 20 women. The pathological changes of teeth were determined by inspection, dental probe, dental mirror and x-ray examination. Epidemiological research was done using average caries index. RESULTS The antropological tooth pathology research of osteological material from the medieval localization of St. Pantaleimon Church in Nis showed the presence of caries in 7.86% cases, 9.93% women and 6.07% men. In 76% caries were localized on the approximal surfaces of teeth. Abrasion of the second and third degree was registered on the side and front teeth with transformation of contact points into contact surfaces and the creation of approximal, interstitial, scolded surfaces. A large quantity of supragingival tartar was found in all individuals aged over 25 years. Expressed alveolar bone resorption is the indicator of generalized periodontal disease. CONCLUSION The prevalence of caries in the studied medieval population from the 12th century was sporadic, with localization on secondary predilection places. The abrasion of the second and third degree was present, and the resorption of the alveolar bone was registered in all the examined skeletal remains, which was the indicator of spread periodontal disease in this period.