bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of the control method (Goc variety) in selection forest management in Western Serbia
Authors: Medarevic M. , Bankovic S. , Pantic D. , Obradovic Snezana
Published: July 2010

The control method, one of the most reliable methods of selection forest management, has been applied in selection forests of western Serbia in a somewhat modified form (Goc variety) for fifty years. This paper analyzes the effects of the control method, i.e. its Goc variety, in the period from 1960/70 - 2000. It is based on the data of five successive complete inventories of the Forest Management Unit (FMU) 'Tara', whose high selection forest of spruce, fir and beech (Piceo-Abieti-Fagetum subass. typicum) trees on diluvium, brown and illimerised soil on limestone, and on limestone in formation with hornfels, are the best quality and the most spacious forests in the Management Class MC 491/1. The effects were monitored through the changes in the distribution of the number of trees and volume per diameter classes, separately for fir as the protagonist of the selection structure, and collectively at the level of a compartment, a typical representative of MC 491/1. Also, the analysis included the changes in the number of trees, volume, current volume increment, yield, and number of recruited trees per unit area (1 ha) by tree species in MC 491/1, occupying an area of 2,648.78 ha. The study results show that in the study period the average volume in MC 491/1 increased by 18.8%, the percentage of conifers increased from 66.0% to 78.5%, and the bearer of the changes was fir. The volume of the mean fir tree increased by 35.9% and it attained 1.086 m3. The volume increment increased by 15.7%. The selection structure of conifers was satisfactory, but there were problems with beech regeneration, in its stable presence and in its achievement of the targeted structure. The number of trees per unit area (1 ha) decreased, which in the long run could have detrimental consequences, but the sustainability in general was satisfactory. The levels of regeneration and recruitment were satisfactory. The health of the trees was improved; the stands were healthy, vital, and biologically and functionally stable. The study results point not only to a series of positive effects of the several-decades' long implementation of the Goc variety of the control method, but also to some problems, the understanding of which will have a corrective role in the future management of selection forests in western Serbia.
Forest fires in Europe from July 22-25, 2009
Authors: Radovanovic M.
Published: July 2010

According to the official data of the FAO, in 43% of cases it is unknown how forest fires come about. By analyzing the available data, a hypothesis has been tested according to which such situations are a result of the connection between the burning of the biomass by charged particles coming from the Sun. It turned out that there was also an analogy in this concrete case, i.e. a temporal link between the processes on the Sun and fires in Europe in the period from July 22nd to 25th 2009. Nevertheless, the hypothesis demands additional laboratory research.
The freshwater snails of the genus Bythinella Moquin-Tandon (Gastropoda: Rissooidea: Hydrobiidae) from Montenegro
Authors: Gloer P. , Pesic V.
Published: July 2010

New records of freshwater snails of the genus Bythinella Moquin-Tandon from Montenegro are presented. Bythinella dispersa, 1973 and B. luteola Radoman, 1976 are recognized and defined as separate species; B. taraensis n. sp., which lives partially sympatric with B. dispersa in the canyon of the River Tara, is described as new. All Bythinella spp. in Montengro inhabit the Dinaric part of the Black Sea drainage area, while it is practically absent from the Adriatic drainage area.
Food composition of some low altitude Lissotriton montandoni (Amphibia, Caudata) populations from North-Western Romania
Authors: Covaciu-Marcov S.D. , Cicort-Lucaciu A.Ş. , Sas I. , Cupşa Diana , Kovacs Eva , Ferenţi Sara
Published: July 2010

The diet of some populations of Lissotriton montandoni from north-western Romania is composed of prey belonging to 20 categories. The food components of the Carpathian newts are similar to those of other species of newts. Most of the prey are aquatic animals, but terrestrial prey also has a high percentage abundance. The consumed prey categories are common in the newts' habitats as well, but in natural ponds the prey item with the highest abundance in the diet is not the most frequent one in the habitat. Thus, although the Carpathian newts are basically opportunistic predators, they still display a certain trophic selectivity.
Binomial symmetries inspired by Bruckman's problem
Authors: Chu Wenchang , You Ying
Published: July 2010

The partial fraction decomposition method is employed to establish two general algebraic identities, which contain consequently several binomial identities and their q-analogues as special cases. 2010 Mathematics Subject Classifications. Primary 05A10; Secondary 05A30. .
Dynamics of Gilpin-Ayala competition model with random perturbation
Authors: Vasilova Maja , Jovanovic Miljana
Published: July 2010

In this paper we study the Gilpin-Ayala competition system with random perturbation which is more general and more realistic than the classical Lotka-Volterra competition model. We verify that the positive solution of the system does not explode in a finite time. Furthermore, it is stochastically ultimately bounded and continuous a.s. We also obtain certain results about asymptotic behavior of the stochastic Gilpin-Ayala competition model. 2010 Mathematics Subject Classifications. 60H10, 34K50. .
Some conditions under which subsequential convergence follows from (A, m) summability
Authors: Çanak İbrahim , Totur Ümit , Dik Mehmet
Published: July 2010

In this paper, we obtain some conditions on a sequence under which subsequential convergence (Math. Morav. 5, 19-56 (2001; Zbl 1047.40005)) of the sequence follows from its (A, m) summability. 2010 Mathematics Subject Classifications. 40A05, 40E05, 40G05. .
β-open and β-closed sets in ditopological texture spaces
Authors: Dost Şenol , Brown Lawrence , Ertürk Rıza
Published: July 2010

The authors define ?-open and ?-closed sets in a ditopological texture space and go on to study ?-compactness and ?-cocompactness, ?-stability and ?-costability, and ?-dicompactness. 2010 Mathematics Subject Classifications. 54A05, 54C10. .
Connectedness and separation in the category of closure spaces
Authors: Baran Mehmet , Tokat Deniz , Kula Muammer
Published: July 2010

In previous papers, various notions of (strongly) closed subobject, (strongly) open subobject, connected and Ti, i = 0, 1, 2 objects in a topological category were introduced and compared. The main objective of this paper is to characterize each of these classes of objects in the category of closure spaces as well as to examine how these generalizations are related. 2010 Mathematics Subject Classifications. 54B30, 54D10, 54A05, 54A20, 18B99, 18D15. .
Lacunary series in mixed norm spaces on the ball and the polydisk
Authors: Jevtic Miroljub , Pavlovic Miroslav
Published: July 2010

We characterize lacunary series in mixed norm spaces on the unit ball Bn in Cn and on the unit polydisk Dn in Cn. 2010 Mathematics Subject Classifications. 32A36, 32A37. .
Computational modelling of failure mechanisms in reinforced concrete structures
Authors: Mark Peter , Bender Michél
Published: July 2010

A modelling approach for macroscopic reinforced concrete (RC) structures and structural elements under static loading conditions is presented. It uses the embedded modelling technique to separately account for concrete volumes and single longitudinal bars or stirrups. The material equations of the 3D elasto-plastic damage model for concrete are derived assuming isotropic damage, stiffness recovery and loss due to crack closing and reopening and a non-associated flow rule. Suitable material functions and material parameters as well as a regularisation by energy criteria are given. The approach is applied to shear beam tests illustrating numerical results compared to corresponding experimental data.
Mathematical modeling of materially nonlinear problems in structural analyses, Part II: Application in contemporary software
Authors: Bonic Zoran , Vacev Todor , Prolovic Verka , Mijalkovic Marina , Dancevic Petar
Published: July 2010

The paper presents application of nonlinear material models in the software package Ansys. The development of the model theory is presented in the paper of the mathematical modeling of material nonlinear problems in structural analysis (part I - theoretical foundations), and here is described incremental-iterative procedure for solving problems of nonlinear material used by this package and an example of modeling of spread footing by using Bilinear-kinematics and Drucker-Prager mode was given. A comparative analysis of the results obtained by these modeling and experimental research of the author was made. Occurrence of the load level that corresponds to plastic deformation was noted, development of deformations with increasing load, as well as the distribution of dilatation in the footing was observed. Comparison of calculated and measured values of reinforcement dilatation shows their very good agreement.
Application of Mindlin's theory for analysis of footing plate bending based on experimental research
Authors: Mladenovic Biljana , Bonic Zoran , Mijalkovic Marina , Dancevic Petar , Davidovic Nebojsa
Published: July 2010

The assumptions and basic equations of the first-order shear deformation plate theory of Mindlin, as one which provides more accurate solutions compared to the classical theory, are briefly presented in this paper. Application of one analytical solution derived according to this theory is presented by use of example of stress-state and deformations calculation of the reinforced concrete footing, which has been the object of recent author's experimental research. Numerical results obtained by applied procedure, which refer to the elastic domain of material behavior, are compared with experimentally obtained data of deflections of footing plate midpoint. .
Organizational growth of SMEs in Serbia: Governance as a built-in limiting growth factor
Authors: Janicijevic Nebojsa , Bogicevic-Milikic Biljana
Published: July 2010

The aim of the study is to investigate the characteristics of governance structures in three Serbian medium-sized enterprises and, particularly, whether the corporate governance influences organizational growth prospects of these firms. The results suggest that in all the companies owners held a tight personal control over all activities, not being willing to delegate any authority to professional managers. This unwillingness of owners to delegate authority actually presents the main barrier for further organizational growth for their firms, and such behavior is, we believe, deeply rooted in the values of the Serbian national culture.
Women in academic profession and male domination
Authors: Tomic Marta
Published: July 2010

This paper presents a case study of women in the academic teaching profession in the context of the Criminal Police Academy, a Belgrade higher education institution of a typically male-dominant type. The aim of the paper is to describe and analyze women's current position and upward career mobility, as well as to discover the causes and mechanisms limiting their weaker (slower) professional recognition. Multiple case method was deployed, on the basis of data collected from various sources: relevant literature on gender inequality of women in the academic profession, official documents of the institution in which the study was conducted, and personal life stories of women research subjects taken through in-depth semi-structured interviews. The results indicate that women who are part of a masculine climate in their academic teaching profession and in their personal life, are arguably in a subordinate position compared to men, and accept their position as quite natural. The research was limited to six typical cases, so that the conclusions may be generalized only with the greatest care; however, researchers who are interested in checking the study's objectivity and validity are provided with the adequate basis for further testing. The research shows that personal perspectives and testimonies of women can contribute to a deeper understanding of their disadvantage in academia, while at the same time contributing to the sociology of the 'individual' and the 'qualitative' by expanding the database on gender issues.
The importance of psychoeducation in systemic family therapy alcoholic treatment
Authors: Dragisic-Labas Sladjana , Djokic Gorica
Published: July 2010

The main goal of the paper was to analyze the impact of psychoeducation in alcoholism therapy treatment on initial motivation and comprehension, change in attitudes to alcoholism, and beginning of creating a new value system. The sample consisted of 166 respondents (83 married couples) that had been involved in one-year systemic group family therapy alcoholic treatment (with the man being alcoholic). A questionnaire on knowledge about alcoholism was used. The respondents were tested three times - at the beginning of the treatment, after 6 months, and after one year. The results showed that the level of education had increased through three phases of the treatment, that motivation changed from initial to substantial, that the comprehension had also changed, turning family system into a more functional model of living. Statistically significant difference in level of education between phase 1 and phase 3 of the family therapy was confirmed. In conclusion, the authors argue for the importance of psychoeducation as a method in treating alcoholism.
NOX2 Deficiency Protects Against Streptozotocin-Induced β-Cell Destruction and Development of Diabetes in Mice
Authors: Xiang Fu-Li , Lu Xiangru , Strutt Brenda , Hill David J. , Feng Qingping
Published: July 2010

OBJECTIVE

The role of NOX2-containing NADPH oxidase in the development of diabetes is not fully understood. We hypothesized that NOX2 deficiency decreases reactive oxygen species (ROS) production and immune response and protects against streptozotocin (STZ)-induced β-cell destruction and development of diabetes in mice.

RESEARCH DESIGN AND METHODS

Five groups of mice—wild-type (WT), NOX2−/−, WT treated with apocynin, and WT adoptively transferred with NOX2−/− or WT splenocytes—were treated with multiple-low-dose STZ. Blood glucose and insulin levels were monitored, and an intraperitoneal glucose tolerance test was performed. Isolated WT and NOX2−/− pancreatic islets were treated with cytokines for 48 h.

RESULTS

Significantly lower blood glucose levels, higher insulin levels, and better glucose tolerance was observed in NOX2−/− mice and in WT mice adoptively transferred with NOX2−/− splenocytes compared with the respective control groups after STZ treatment. Compared with WT, β-cell apoptosis, as determined by TUNEL staining, and insulitis were significantly decreased, whereas β-cell mass was significantly increased in NOX2−/− mice. In response to cytokine stimulation, ROS production was significantly decreased, and insulin secretion was preserved in NOX2−/− compared with WT islets. Furthermore, proinflammatory cytokine release induced by concanavalin A was significantly decreased in NOX2−/− compared with WT splenocytes.

CONCLUSIONS

NOX2 deficiency decreases β-cell destruction and preserves islet function in STZ-induced diabetes by reducing ROS production, immune response, and β-cell apoptosis.
MafA and MafB Regulate Genes Critical to β-Cells in a Unique Temporal Manner
Authors: Artner Isabella , Hang Yan , Mazur Magdalena , Yamamoto Tsunehiko , Guo Min , Lindner Jill , Magnuson Mark A. , Stein Roland
Published: July 2010

OBJECTIVE

Several transcription factors are essential to pancreatic islet β-cell development, proliferation, and activity, including MafA and MafB. However, MafA and MafB are distinct from others in regard to temporal and islet cell expression pattern, with β-cells affected by MafB only during development and exclusively by MafA in the adult. Our aim was to define the functional relationship between these closely related activators to the β-cell.

RESEARCH DESIGN AND METHODS

The distribution of MafA and MafB in the β-cell population was determined immunohistochemically at various developmental and perinatal stages in mice. To identify genes regulated by MafB, microarray profiling was performed on wild-type and MafB−/− pancreata at embryonic day 18.5, with candidates evaluated by quantitative RT-PCR and in situ hybridization. The potential role of MafA in the expression of verified targets was next analyzed in adult islets of a pancreas-wide MafA mutant (termed MafAΔPanc).

RESULTS

MafB was produced in a larger fraction of β-cells than MafA during development and found to regulate potential effectors of glucose sensing, hormone processing, vesicle formation, and insulin secretion. Notably, expression from many of these genes was compromised in MafAΔPanc islets, suggesting that MafA is required to sustain expression in adults.

CONCLUSIONS

Our results provide insight into the sequential manner by which MafA and MafB regulate islet β-cell formation and maturation.
Impact of A1C Screening Criterion on the Diagnosis of Pre-Diabetes Among U.S. Adults
Authors: Mann Devin M. , Carson April P. , Shimbo Daichi , Fonseca Vivian , Fox Caroline S. , Muntner Paul
Published: July 2010

OBJECTIVE

New clinical practice recommendations include A1C as an alternative to fasting glucose as a diagnostic test for identifying pre-diabetes. The impact of these new recommendations on the diagnosis of pre-diabetes is unknown.

RESEARCH DESIGN AND METHODS

Data from the National Health and Nutrition Examination Survey 1999–2006 (n = 7,029) were analyzed to determine the percentage and number of U.S. adults without diabetes classified as having pre-diabetes by the elevated A1C (5.7–6.4%) and by the impaired fasting glucose (IFG) (fasting glucose 100–125 mg/dl) criterion separately. Test characteristics (sensitivity, specificity, and positive and negative predictive values) using IFG as the reference standard were calculated.

RESULTS

The prevalence of pre-diabetes among U.S. adults was 12.6% by the A1C criterion and 28.2% by the fasting glucose criterion. Only 7.7% of U.S. adults, reflecting 61 and 27% of those with pre-diabetes by A1C and fasting glucose, respectively, had pre-diabetes according to both definitions. A1C used alone would reclassify 37.6 million Americans with IFG to not having pre-diabetes and 8.9 million without IFG to having pre-diabetes (46.5 million reclassified). Using IFG as the reference standard, pre-diabetes by the A1C criterion has 27% sensitivity, 93% specificity, 61% positive predictive value, and 77% negative predictive value.

CONCLUSIONS

Using A1C as the pre-diabetes criterion would reclassify the pre-diabetes diagnosis of nearly 50 million Americans. It is imperative that clinicians and health systems understand the differences and similarities in using A1C or IFG in diagnosis of pre-diabetes.
Genetic diversity of avian blood parasites in SE Europe: Cytochrome b lineages of the genera Plasmodium and Haemoproteus (Haemosporida) from Bulgaria
Authors: Dimitrov Dimitar , Zehtindjiev Pavel , Bensch Staffan
Published: July 2010

We used a nested PCR protocol to examine the genetic diversity of cytochrome b (cyt b) lineages from blood parasites of the genera Plasmodium and Haemoproteus in birds in Bulgaria. In total, 460 birds of 43 species and 14 families (mostly passerines) were examined for the presence of infections. Of them, 267 were recognised as infected with haemosporidian parasites. Mixed infections were recorded in 24 individuals (9%). Besides the 24 individuals with mix infections, 114 (43%) were positive for Plasmodium spp. and 129 (48%) for Haemoproteus spp. We identified 52 genetic lineages of haemosporidian parasites: 38 of Haemoproteus and 14 of Plasmodium. Twelve new cyt b lineages of Haemoproteus were recorded; they occurred in the following hosts: grey-faced woodpecker (Picus canus), golden oriole (Oriolus oriolus), jay (Garrulus glandarius), barred warbler (Sylvia nisoria), song thrush (Turdus philomelos), spotted flycatcher (Muscicapa striata), spanish sparrow (Passer hispaniolensis), hawfinch (Coccothraustes coccothraustes), and cirl bunting (Emberiza cirlus). We also detected 22 new host records for previously known lineages. The most common lineage was SGS1 (Plasmodium relictum), which had a total prevalence of 14% and occurred in 8 host species belonging to 5 families. Three of the cyt b lineages of genus Haemoproteus (DURB1, DURB2 and SYNIS2) showed more than 5% divergence from all described morphologically lineages. These lineages probably represent at least 2 different morphospecies which remains to be identified.
Ephemeral gully erosion from agricultural regions in the Pacific Northwest, USA
Authors: Barber Michael , Mahler Robert
Published: July 2010

Ephemeral gully erosion from agricultural regions in the Pacific Northwest, USA

Soil erosion continues to be problematic financially and environmentally with the USEPA ranking sediment as one of the top ten pollutants of concern in the USA. One aspect of erosion often overlooked is the role of ephemeral gullies in terms of quantity of sediment produced and amount exported to nearby waterways. Current physically-based and empirical models are inadequate for predicting this type of erosion particularly at the watershed scale. A new methodology for predicting the quantity and location of sediment delivery was developed and tested via a case study. Aerial ephemeral gully erosion rates varied from 33.6 mton/km2 (0.15 U.S. tons/acre) in the Big Bear Creek basin to 88.4 mton/km2 (0.39 U.S. tons/acre) in the Middle Potlatch Creek basin representing 2.3 to 7.7% of the total surface sediment load. This information was used to develop a predictive Erosion Potential Index (EPI) that uses LANDSAT aerial imagery combined with readily available soils information and a digital elevation model to identify the most probably locations of ephemeral gully development. High resolution aerial imagery was used to quantify actual ephemeral gully locations which were then compared to the EPI predicted locations to verify the procedure. High resolution aerial imagery was also used to quantify the amounts of soil erosion from ephemeral gullies in basins of the Potlatch River system.
The role of thaumatin II in cucumber resistance against Tetranychus urticae Koch: laboratory and greenhouse evaluation
Authors: Kiełkiewicz Małgorzata , Czarnecka Małgorzata , Orzechowski Sławomir , Szwacka Maria
Published: July 2010

The role of thaumatin II in cucumber resistance against Tetranychus urticae Koch: laboratory and greenhouse evaluation

The role of thaumatin II in the resistance of transgenic cucumber plants of the T6 generation against the two-spotted spider mite (TSSM) (Tetranychus urticae C. L. Koch 1836, Acari: Tetranychidae) was determined in greenhouse experiments evaluating: (1) mite behaviour towards cucumber lines (T224 09, T212 01, T210 06) differing in the level of thaumatin II expression, (2) mite reproductive capacity, (3) mite colonisation ability, and (4) mite leaf damage. Additionally, using Western blot, the presence of thaumatin II in leaves of transgenic cucumber plants of the T6 generation was analysed before and after TSSM feeding. Even plants with a relatively high leaf thaumatin II level (T224 09 and T212 01) were equally well accepted by TSSM in a ‘free-choice’ test, which excludes thaumatin II as an important factor in the process of host plant acceptance. However, a reduced fecundity of mite females and a lower, than in the control, number of mites found in the period of permanent feeding on thaumatin-rich plants, indicate a putative role of thaumatin II in the plant-mite interactions. The lack of a clear relationship between the level of thaumatin II and plant resistance to TSSM may be a sign that thaumatin II is not a direct factor involved in antibiosis. In response to TSSM, the thaumatin II content decreases, increases, or remains unchanged in mite-infested leaves, which excludes thaumatin II as being directly involved in induced defence.
Variation of selected morphological characters of the cave mite Oribella cavatica Kunst, 1962 (Acari, Oribatida)
Authors: Żbikowska-Zdun Krystyna , Piksa Krzysztof , Smaczyńska Anna
Published: July 2010

Variation of selected morphological characters of the cave mite Oribella cavatica Kunst, 1962 (Acari, Oribatida)

Two populations of Oribella cavatica were examined. The mites were isolated from bat guano collected in February 2006 in Zbójecka Cave in Mount Łopień and in the cave Czarci Dół, which are situated in the Beskid Wyspowy Mountains, within the Flysch Carpathians in southern Poland. Coefficients of variation of body length and width, lamella length, and sensillus length of this species under stenotopic conditions were compared with those of two eurytopic species. The stable variation of sensillus length of O. cavatica, like differences in the variation of Heminothrus peltifer in various soil habitats, may have bioindicative significance.
Luminescence of Fe-substituted ZnWO4 powders synthesized by aqueous solution reaction
Authors: He H. Y. , Huang J. F. , Cao L. Y. , Wu J. P. , Chen P.
Published: July 2010

Fe-substituted ZnWO4 as a possibleopticalmaterialhas someinteresting properties. We report a comparison of luminescence properties of pure ZnWO4 and Zn0.99Fe0.01WO4 powders synthesized with aqueous salt metathesis reaction in this work. The experimental results indicated that the Fe-substitution results in decreases in the crystallinity and grain size. In comparison with the pure ZnWO4, the Zn0.99Fe0.01WO4 powder shows a small intensity of blue-green emission band, significantly smaller intensity of emission peaks at longer wavelength, large half-widths of the emission bands, and a red emission band at a range of 590–680 nm. The results clearly indicate that the red emission band is related to the Fe3+ cation.
Insulation properties of bricks made with cotton and textile ash wastes
Authors: Binici Hanifi , Gemci Remzi , Aksogan Orhan , Kaplan Hasan
Published: July 2010

Huge amounts of cotton and textile ash waste are disposed of by countries all over the world. The majority of cotton wastes and textile ash wastes is expelled in such a way as to cause serious environmental problems. The present study involves experimental research investigating the potential use of cotton and textile ash wastes combination for producing a new and lightweight composite building material with good insulation properties. The results showed that the cotton and textile ash waste bricks fulfill the compressive strength and heat conductivity requirements of the ASTM and Turkish Standards. A cotton and textile ash waste brick house has been found to be superior to a concrete brick house for regulating indoor temperatures. The production process can be easily applied in conventional brick plants. The product is a light weight composite which can be used for making bricks and wall and ceiling panels with good insulation properties.
Effects of homogenizing and aging treatments on the microstructure and microhardness of an Nb-silicide based ultrahigh temperature alloy
Authors: Guo Haisheng , Guo Xiping
Published: July 2010

To investigate the effects of homogenizing and aging treatments on the microstructure and microhardness of an Nb-silicide based ultrahigh temperature alloy, coupons were homogenized at 1 300–1 600°C for 50 h, and then aged at 1 100°C for 50 h. The results show that the phase constituents of the heat-treated alloys are still Nb solid solution and silicides, α-(Nb,X)5Si3 phase forms after heat-treatments at temperatures above 1 500°C. With the increase in heat-treatment temperature, the original big polygonal and plate-like silicides gradually break into small ones, and the amounts of retained typical lamellar and rod-like eutectic colonies reduce clearly. The variation of partitioning ratios of alloying elements between Nb solid solution and silicides causes the change in microhardness of the alloy. 1 500°C/50 h + 1 100°C/50 h is an optimum heat-treatment process.
Experimental investigation and thermodynamic prediction of the Ga–Sb–Sn phase equilibria
Authors: Manasijević Dragan , Minić Duško , Živković Dragana , Talijan Nadežda , Živković Živan
Published: July 2010

Optimized thermodynamic data, successfully used for phase diagram calculations of constitutive binary systems, were used for prediction of phase equilibria in the ternary Ga–Sb–Sn system. The projection of the liquidus surface, invariant equilibria and three vertical sections with molar ratios Sb:Sn = 1, Ga:Sn = 1 and Ga:Sb = 1 of the Ga–Sb–Sn ternary system were calculated using the CALPHAD method. Alloys, situated along three selected vertical sections, were investigated using differential scanning calorimetry. The experimental phase equilibria data from this work and literature were compared with calculation results.
Simulation-based study of the compensation coil method applied to ferrite nanometric powders
Authors: Osaci Mihaela , Cunţan Corina , Panoiu Caius
Published: July 2010

The magnetic materials studied most by current international projects are based on ultrafine particles, in solid or liquid matrix. In order to design a good magnetic material based on nanoparticles, it is required to know their magnetic properties. Magnetic measurements represent a relatively difficult area of electrical engineering. In order to find the magnetic properties of nanometric magnetic powders, it is very difficult to use a traditional measurement method (e.g. using a toroidal coil). In this case, it is advisable to use compensation methods. In this paper, we present a study, based on simulation, of the compensation coil installation used to obtain the magnetisation curve of the ferrite nanometric powders of NiZn to 50 Hz. The experimental installation consists of a magnetisation circuit with two identical coils, connected in opposition, and a secondary circuit used to compensate the voltages induced in the identical probe coils, without sample. The parameters for which we obtain good secondary circuit compensation are simulated by the Electronics Workbench program – version Multisim 8.
Descripción y análisis del proceso de evaluación de la calidad de las revistas cientíﬁcas españolas llevado a cabo por FECYT en el año 2008
Authors: Coslado M. Ángeles , Báez José Manuel , Lacunza Izaskun
Published: July 2010

La Fundación Española para la Ciencia y Tecnología (FECYT), dentro del proyecto de apoyo a la profesionalización e internacionalización de las revistas cientíﬁcas españolas (ARCE), realizó en el año 2008 la primera edición de la evaluación de la calidad de las revistas cientíﬁcas españolas. El objetivo principal de este estudio es doble. Por un lado, describir y analizar el proceso detallando sus características y las distintas fases de la evaluación. Por otro, establecer unas propuestas de mejora a tener en cuenta en próximas ediciones. Además, se estudian de forma cuantitativa los resultados obtenidos. A pesar de que la muestra analizada en el trabajo es relativamente pequeña, las tendencias que se observan en los resultados son de interés, puesto que reﬂejan de forma signiﬁcativa la situación nacional, a la espera de ser conﬁrmados al aumentar la estadística en sucesivas ediciones.
Towards Sustainable and Environmentally Friendly Enhanced Oil Recovery in Offshore Newfoundland, Canada
Authors: Thomas Brandon George , Iliyas Abduljelil , Johansen Thormod Ekely , Hawboldt Kelly , Khan Faisal
Published: July 2010

A consortium of university-industry researchers are developing sustainable and environmentally friendly enhanced oil recovery (EOR) technology for oil fields off the east coast of Newfoundland, Canada. This paper is foundational work on potential implementation of air and flue gas injection techniques. The paper discusses reservoir and facility considerations of air and flue gas injection and provides recommendations for project evaluation. The paper presents screening level results for Husky Energy's White Rose Field as a case study.

Newfoundland offshore fields contain light oil (30-37 oAPI, 0.5-0.8 cP) making the fields potential targets for gas based EOR. However, with the oil fields located 310-350 km off the coast, availability of injection gas and logistical problems present barriers to EOR. Air injection has the advantages of an unlimited supply of injectant, success in laboratory and field applications, years of safe operation, and potential for an estimated 10% incremental oil recovery in waterflooded reservoirs. The challenges toward implementation of both techniques considering field characteristics and infrastructure are discussed along with practical solutions to aid implementation.

The evaluation of sustainable and environmentally friendly EOR technologies is inline with long-term regulatory requirement and is timely as oil production from existing fields is beginning to decline. Moreover, with only 3 of over 20 discovered fields off the coast of Newfoundland currently developed, the conclusions and recommendations may also be valuable in the near future for evaluation of EOR techniques for the remote fields offshore Newfoundland.

Introduction

When evaluating the potential for enhanced oil recovery offshore Newfoundland, two key themes must be addressed;Is the process suitable for the reservoir properties and reservoir fluids?Is the process suitable for implementation offshore?

The challenges of implementing enhanced oil recovery (EOR) in an offshore environment are much greater than in an equivalent onshore field (Bondor et al., 2005). While EOR processes tend to be reservoir and reservoir fluid specific, the project must be commercially feasible within the high cost offshore environment. Beyond normal offshore conditions, Newfoundland's offshore oil fields occur in one of the harshest offshore environments in the world, with severe weather and ice encroachment for long periods during the spring and summer.

The two enhanced oil recovery techniques discussed within this document are high pressure air injection (HPAI) and flue gas injection. Both processes supply additional energy to the reservoir by the injection of non-hydrocarbon gases with the aim of recovering incremental oil.
Key learnings: Risk based verification of process systems on a floating LNG producing unit
Authors: Skramstad Erik , Almandoz David Anthony , Savio Fredik
Published: July 2010

LNG production facilities installed on a floating unit are currently being developed by several companies. Such facilities involve process applications similar to those that are commonly in use in the industry but have not been previously deployed on a floating unit in a marine environment.

FLEX LNG commissioned DNV and CH-IV International to review their process solution with the aim to verify the performance of the process.

A novel and risk based approach was adopted to ensure an efficient and focussed review in which the systematic application of DNV's Technology Qualification procedure was adopted as a means to screen the solutions and identify areas of particular concern.

The identified areas were subjected to detailed and expert technical assessment and on this basis a total assessment of the system solution was made.

The technical assessment included the review of use of columns and heat exchangers in liquid and gas operations and novel application of mechanical components and rotating equipment.

It was demonstrated that the majority of the effects of the vessel motions and the marine environment had been identified and addressed in the design of the plant and that no major issue that could not be addressed (showstoppers) was identified. Further, it was concluded that the selected approach provided an effective and focussed assessment of the process solution.

This paper will present–Background for the verification–The selected approach–Discussion of some of the identified issues and their impact–Key conclusions and recommendations

Introduction

LNG production facilities on floating facilities (FLNG or LNG FPSOs) are being considered and developed by several companies with the aim to monetise stranded gas fields. The results from these studies indicate that these solutions are technically feasible and also that the benefits from fabrication in industrialised facilities as opposed to field-erected facilities make these solutions attractive in an investment perspective compared to many land based facilities.

The experience base from LNG liquefaction processes on floating facilities is limited to experience gained from reliquefaction plants on LNG carriers and from similar process applications on LPG FPSOs. The experience base for typical oil FPSOs is significant, but not fully applicable due to the complexity of the processes involved in LNG production when compared to process designs commonly employed for FPSOs.

A key uncertainty in the assessment of the commercial feasibility of a FLNG field development will be the performance and capacity of the production chain which will involve novel solutions both with regard to production facilities, offloading and the transport solutions.
Parque das Conchas (BC-10) Steel Lazy Wave Riser Installation: Pre-Abandonment, Recovery and Transfer Challenges
Authors: Thomas Biju , Benirschke Anton , Sarkar Tanmay
Published: July 2010

The Parque das Conchas (BC-10) project is located in deepwater, in block BC-10, off the coast of Brazil. It comprises a number of subsea fields tied back to a centrally located turret moored Floating Production Storage and Offloading (FPSO) host in some 1800 meters of water. This paper describes the installation engineering challenges for the 7 Steel Lazy Wave Risers (SLWR) and the dynamic sections of the 3 umbilicals that are part of the Phase 1 scope of the project.

To decouple the schedule risk of the installation of the subsea systems from the FPSO arrival schedule, a pre-abandonment, recovery and transfer method of the SLWR and umbilical in lazy wave configuration was chosen. Successful installation of SLWR by this method to the FPSO turret required the design of a suitable pre-abandonment layout taking into consideration the installation sequence and careful assessment of the risks involved particularly in terms of clearance and interference issues with FPSO mooring lines and the already transferred SLWRs/ umbilicals.

Pre-abandonment, recovery and transfer by keel haul of this " worlds first?? SLWR system had a number of challenges that had to be overcome. These include determining the pre-abandonment route of SLWR, lay tension to balance curve stability, lazy wave ‘hump’ stability while on seabed, lay stresses on flex joint, etc.

The recovery and transfer operations had challenges associated with clearance monitoring with mooring lines and already installed risers as well as maintaining the design touch down points.

The pre-abandonment layout was developed using Shell's in-house design tool for high level assessment followed by detailed engineering installation analysis by Subsea7 using Orcaflex. This enabled the development of analytical procedures to assess and mitigate the risks involved in pre-abandonment, recovery and transfer operation of SLWR. Subsea7's construction vessel ‘Seven Oceans’ performed the SLWR and dynamic umbilical installation activities.

This paper describes how this complex riser operation was modeled and successfully executed.

Introduction

The Parque das Conchas (BC-10) project is located off the coast of Brazil in the Campos Basin in water depths from 1190 meters to 1940 meters. Shell is the operator with a 50% working interest in a Joint Venture with Petrobras (45%) and ONGC (15%). During Phase I of the project, the Ostra, Abalone and Argonauta B-West fields were tied-back via SLWR's to the turret-moored FPSO in approximately 1800m water depth as presented in Figure 1. Argonauta O-North is planned to be developed as part of Phase II of the project.
SS: Atlantic Canada
Authors: Paulin Mike , Thistle Stephen , Kennedy Kurt
Published: July 2010

A study was completed in early 2008 (IMVPA, 2008) for the US Minerals Management Service (MMS) with the objective to deliver an assessment of oil and gas technology that may be applied to cold regions of the United States Outer Continental Shelf (OCS). An overview of this study and its results are presented in this paper.

This study assessed the current state of offshore technology in arctic and sub-arctic regions. The results of this assessment were used to provide insight and guidance into existing/future exploration and development technologies that might be applied on the US OCS, in particular those areas in the Beaufort, Chukchi and Bering Seas.

The work covers exploration structures, bottom-founded and fixed production concepts, floating production concepts, terminals, pipelines and subsea facilities, and also touches on other technologies that might be relevant to Alaskan OCS exploration and development. Advances in harsh environment offshore exploration and production technology have made it economically and technically feasible for some projects to proceed in ice-covered waters, and additional projects may be possible in future.

This study drew on a review of current state-of-practice and state-of-the-art used in, or proposed for, arctic and sub-arctic offshore development areas. Assessments of exploration and production options were primarily based on technical feasibility. As appropriate, other aspects were also considered including constructability, capital costs, environmental considerations, operations, maintenance and repair, abandonment and decommissioning.

Introduction

Offshore hydrocarbon exploration and production requires a bottom-founded platform, an artificial island, or a floating structure plus subsea equipment including pipeline/riser systems. Transportation of produced hydrocarbons to market is also an essential aspect of any development. An added complexity when hydrocarbon resources are located in arctic regions is the presence of first-year and/or multi-year ice during a significant part of the year. Global climate changes may also result in longer open water seasons in the future, which may lead to more significant storm events that must be considered in the design of full-field offshore development concepts for arctic regions.

A number of " cold regions?? offshore developments have been carried out or are planned worldwide, including the east coast of Canada (Hibernia, Terra Nova, White Rose), Sakhalin Island (Russia), Kashagan (Caspian), Shtokman (Barents Sea) as well as in the Beaufort Sea (Northstar, PanArctic Drake). An understanding of these analogue projects, as well as those already operational or planned for the United States (e.g., Northstar and Oooguruk), can provide insight and guidance into potential exploration and development technologies that might be applied to cold regions of the United States Outer Continental Shelf (OCS).
Offshore Petroleum Play Fairway Analysis and Geoscience Data Package Program
Authors: Van Belle Olivier Stephan Eduard , Wilson Hamish , Luheshi Matt , MacMullin Roderick Alexander , St-Amour Wayne
Published: July 2010

The Nova Scotia Department of Energy and Canada-Nova Scotia Offshore Petroleum Board have carried out a sound technical work program over many years to present potential licensees with the information to encourage them to invest in Nova Scotia. However, following some success, the result in terms of licence bids in Nova Scotia's offshore, wells drilled and hydrocarbons won, has proved disappointing. The value of the hydrocarbon province has not been fully unlocked. Although production and proven discoveries demonstrate that there is a working hydrocarbon system oil companies are leaving Nova Scotia in favour of other opportunities prior to completion of their exploration program. There is a view that, in order to attract new investors, it will be necessary to lower the barriers to entry. One of these is undoubtedly the ability of new investors to easily and quickly develop a good geological understanding of the Nova Scotia offshore basins and thus investment decisions. The intent is to conduct an industry-standard sequence stratigraphic based Play Fairway Analysis to a level of detail that is sufficient to give credibility to the outcome. It is also intended to conduct special studies that can help address the key exploration risks. Furthermore, this paper elaborates on the importance of the Geoscience Data Package for this program, and its effectiveness in re-invigorating interest in the Scotian Margin. Data availability, to support the comprehensive geotechnical evaluation, is key to reducing the barriers to entry into the region, but unfortunately it is not easily accessible to investors. The lack of a publicly available and industry-credible, geological framework, in conjunction with the fact that most geoscience data, specifically seismic data, is not freely available in full digital format is a major hurdle. The Offshore Petroleum Play Fairway Analysis and Geoscience Data Package program, for which the business rational is discussed in this paper, are aimed at addressing this issue.
SS: Perdido Development Project: Spar & Moorings
Authors: Lohr Curtis , Smith Keith
Published: July 2010

A Spar was selected for the Perdido Development during system selection in 2005 to provide a stable platform for direct vertical access drilling and producing operations for the world's deepest drilling and production platform in nearly 8000 feet of water. A combination polyester / chain mooring system was selected to place less vertical load on the floating structure (compared to a steel mooring system), which results in less payload on the structure and a lower overall cost solution for the project's host platform.

The transportation and installation of the Perdido Spar and moorings was completed during 2008. A number of records were set during the installation campaign including the world's deepest Spar installed in 7817 feet of water and the world's deepest permanent mooring pile in 8631 feet of water.

Challenges of interest to the offshore industry that contributed to the uniqueness of the Perdido Spar and moorings were:Impacts of Topsides single lift on the Spar design and weight managementSafety management given a project goal of zero recordable injuriesUltra deep water location with increased environmental requirements and significant seafloor hazardsPolyester permanent mooring systemSpar fixed ballast installation accuracySpar installation during hurricane season

This paper will provide a broad overview of various aspects of the Perdido Development Spar and mooring system design, fabrication, transportation and installation while highlighting the main challenges encountered and lessons learned for future projects.

Introduction

The Perdido Spar is Shell's first Spar Host production platform, but has the benefits of being developed as a joint venture with Chevron and BP. Technip was selected as the Spar and Mooring contractor in April 2006 and began detailed design on their 14th Spar in June 2006. An EPC contract was awarded to Technip USA in November 2006 for design, fabrication and dry transport of the Spar and Mooring work scope on the Perdido Development project. The Spar & Mooring Leads for Shell were primarily co-located with the Technip project management team at Technip's Woodbranch II PM&E office and in Shell's Woodcreek office in Houston. The Spar Fabrication Site Team was located at Technip Offshore Finland's yard in Mantyluoto, Finland.

Working relationships with Technip were excellent and were developed early in the project through focused team building sessions in Finland and Houston. An alignment workshop primarily aimed at " incident and injury free?? safety management and working relationships was held in October 2006 and attended by the most senior management from both Shell and Technip.

Heerema Marine Contractors (HMC) was selected in early 2006 as the transportation and installation contractor (excluding the dry tow from Finland). The Heerema project team was based in Leiden, The Netherlands while the Shell T&I team was based in Shell's Woodcreek office in Houston.