bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimized Filter Cake Breaker Successfully Used in the OH Completions in Yuralpa and Oso Fields
Authors: Torres Camilo , Sinche Galo , Navarro Raul , Endara Edison , Carreón Francisco , Murillo Pablo , Cortez Santiago
Published: June 2013

Oil provides 51% of Ecuador export earnings and a third of government revenue. Horizontal drilling has become an option to increase domestic oil production. The Yuralpa and Oso are land oil producer fields in Ecuador, which includes several wells. Some of the challenges include low pore pressure, sand control and the need of a filter cake breaker to enhance productivity. The reservoir drill-in fluid (RDF) and the breaker needed to be compatible, as well the operator required a breaker formulation that would not only allow the upper completion to be run before losing filtration control but also deliver superb productivity on completion after adequate soak time. It was also important that the solution as well required to be cost effective due to the low AFE that the operator had on the project. A water based breaker system, comprised of enzyme and chelant components, was chosen as the treatment selection. The thin RDF filtercake and the breaker treatment combination were tested in the laboratories to achieve an optimum technical and economical solution for the project. Due to environmental restrictions, sodium formate was used to provide density for drilling the horizontal hole section. After drilling, a mechanical and chemical wellbore clean up were performed, the pre-perforated liner was run, and the filter cake breaker was spotted at the open hole

Potassium chloride brine was used as final completion fluid. Operations continue running in hole the upper completion assembly which some times includes an electric submersible pump (ESP). The usage of the novel breaker system allowed the project to achieve higher production rates than expected. Several wells have been successfully completed and put in production, all achieving or exceeding production expectations.
Properties and Applications of an Alternative Aminopolycarboxylic Acid for Acidizing of Sandstones and Carbonates
Authors: Reyes Enrique A. , Smith Alyssa L. , Beuterbaugh Aaron
Published: June 2013

Significant advances in acidizing chemistry have led to the introduction of sequestering agents, such as hydroxypolycarboxylic acids, followed by chelating agents, to mitigate precipitation reactions. The initiative to obtain fluids with an improved environmental footprint has led to the redesign of treatment fluids to possess distinct advantages, such as stability at higher temperature, broader pH activity, and stronger complex formation. In the area of hydrofluoric (HF) acidizing chemistry, the conceptualization of the unique HF acid reactions on clays and silica surfaces—namely, kinetic controls over the so-called primary, secondary, and tertiary reactions—has facilitated fluid designs that can handle such varied reactions. The work presented here describes the development of a new acidizing fluid containing an environmentally relevant chelating agent and an aminpolyocarboxylic acid.

The chelating agent is fully biodegradable, according to the Organization for Economic Co-operation and Development (OECD) protocols, is stable in fluid media from pH 1 to 7 and at high temperatures, and stabilizes the dissolved ions during an acidizing treatment. In HF acidizing, the chelant performance has been tested at 0.6 mol/L and HF acid concentrations from 0.5 to 2%, pH of 2.5 to 4, including a stabilizing agent to mitigate the precipitation of fluorosilicates or fluoroaluminates, and is effective in temperature ranges from 200 to 300°F. Laboratory tests show it to be effective in maintaining in solution dissolved aluminum (3000 to 10 000 mg/L), calcium (5000 mg/L), and iron (6000 mg/L). The use of nuclear magnetic resonance (NMR) spectroscopic analysis revealed additional dissolved-fluoride-containing species that has not been previously reported. Moreover, the chelating agent can also be used when stimulating carbonate rocks in concentrations from 0.2 to 0.6 M with a pH of 1 to 4 and is effective from 125 to 350°F. The representative pore volume breakthrough (PVbt) curves provide an indication of the distinct reactivity of this chelant.
Impact of Fe (III) on the Performance of VES-Based Acids
Authors: Shu Yi , Wang Guanqun , Nasr-El-Din Hisham A. , Zhou Jian
Published: June 2013

Viscoelastic surfactant (VES)-based acid systems have been used successfully in matrix and acid fracturing treatments. However, the existence of Fe (III) as a contaminant in such systems may lead to many problems, due to interactions between VES and Fe (III). Such interactions could reduce the effectiveness of VES-based acid systems and may lead to formation damage.

In this paper, reaction mechanisms between VES and Fe (III) were studied. Rheological properties of two surfactants were examined with various concentrations of Fe (III). A scanning electron microscope (SEM) was used to identify precipitates from reaction products. Inductively coupled plasma (ICP) was applied to measure iron concentration, and the two-phase titration method was used to determine VES concentration in all phases of the sample. The effect of several chelating agents on the reaction of VES with Fe (III) was also examined.

Experimental results indicate that the apparent viscosity of live VES-based acids (20 wt% HCl, 4 vol% VES) increased from 14 to 751 cp at a shear rate of 10 s-1 when the Fe (III) concentration was increased from 0 to 2,300 ppm, and started to decrease at higher Fe (III) concentrations. This is because of the electrical bonding between negative charged [FeCl4]- groups and positive charged amine groups in VES in live acids. Both surfactants interacted with Fe (III) and precipitates, which are complexes containing iron and VES, were noted at 5,000 ppm and higher concentrations of Fe (III). On the other hand, adding a chelating agent [1:1 mole ratio to Fe (III)] reduced the apparent viscosity of the sample to no more than 40 cp at the shear rate of 10 s-1 when Fe (III) concentration is lower than 4,000 ppm, which means that the chelating agent reacted with Fe (III) and reduced interactions between VES and Fe (III). Adding a suitable chelating agent can minimize the impact of Fe (III) on VES-based acids.
Thermal Decomposition of Chelating Agents and a New Mechanism of Formation Damage
Authors: Sokhanvarian Khatere , Nasr-El-Din Hisham A. , De Wolf Corine A.
Published: June 2013

Chelating agents are used in the oil and gas industry mainly to: remove inorganic scales, control iron during acid treatments, and stimulate carbonate/sandstone reservoirs. The main chelating agents used in the field, include: ethylenediaminetetraacetic acid (EDTA), N-(hydroxyethyl)-ethylenediaminetriaacetic acid (HEDTA), and recently glutamic acid-N, N diacetic acid (GLDA). As with all organic acids, one of the main concerns with using these chelates is their stability at elevated temperatures. Therefore, the objectives of the present study are to: 1) assess thermal stability of various chelates, and 2) examine the effect of thermal degradation products on the permeability of carbonate and sandstone cores.

We prepared solutions (0.4 to 0.6 M) of HEDTA, GLDA, EDTA, and their salts. The solutions of these chelates were heated at various temperatures up to 400°F and times (2 to 12 hrs.). The thermal stability of these chelating agents was determined by measuring the concentration of the chelates before and after heating using a titration method utilizing FeCl3 as a titrant. Mass spectrometry was used to determine the degradation products. We injected GLDA to high permeability Indiana limestone, and investigated the effect of soaking of GLDA at high temperature on the final permeability of the core. Coreflood tests were conducted at 340°F and 5 cm3/min.

Chelating agents degraded at temperatures greater than 350°F. The decomposition products included: iminodiacetic acid, acetic acid, and ⍰-hydroxy acids. The addition of salt and raising pH improved the thermal stability of chelates. Thus, careful design of the chelate-based treatment fluids can prevent loss of functionality at elevated temperatures in the field, enhancing the versatility of these solutions, and minimizing formation damage due to decomposition products.
Effectively Controlling Proppant Flowback to Maximize Well Production: Lessons Learned from Argentina
Authors: Nguyen P. D. , Bonapace J. C. , Kruse G. F. , Solis L. , Daparo D.
Published: June 2013

Flowback of proppant and formation sand often poses serious challenges to operating companies. These solids can cause equipment damage, costly and frequent cleanup treatments, and production decreases. Various mechanisms were found that destabilize the proppant pack, causing the proppant to produce back with the production fluid. Since 2005, curable resin systems for coating proppant on-the-fly during hydraulic fracturing completions and remedial proppant treatments of propped fractures have been applied in Argentina to provide an effective means for proppant flowback control and screenless completions in various basins.

Evaluation of these applications has helped determine that optimum concentrations of resin coatings on the proppant in either primary or remedial treatments are necessary to maximize the bonding between proppant grains to lock the grains in place while minimizing any reduction of the proppant pack conductivity. Additives included in the liquid resin systems permit good consolidation properties in the proppant pack, allowing it to effectively handle the shear forces of high production rates and multiphase flow and the effect of stress cycling as the well undergoes producing and being shut in.

Field results indicate that on-the-fly resin coating on proppant and remedial treatments effectively stops the proppant from producing back while allowing the well production rates to be maximized as designed. These processes have drastically decreased the number of solids cleanout workovers in the treated wells compared to the offset wells in the same field where resin treatments were not performed. These resin treatments provide a reliable and cost-effective alternative in marginal reservoirs, eliminating the need for sand screens and providing access to other intervals when deemed necessary without wellbore restrictions.
A Novel Approach for Predicting In-situ Breakdown Conditions for Wireline Mini-Fracture Testing
Authors: Barnhoorn Auke , Magalhaes Boris Sintra , Subbiah Surej Kumar , Zitha Pacelli
Published: June 2013

Wireline dual-packer mini-fracture testing jobs are used to determine the critical formation breakdown parameters needed for field-scale hydraulic fracture design, water and gas injection management, wellbore stability and sand production. A wireline dual-packer mini-fracture test consists of injection a small volume of fluids at constant flow rate into an open borehole to pressurize the formation and induce fracturing.

The performance of a wireline mini-fracture test and formation failure depends on far-field stress conditions, rock properties (geomechanical properties: elastic properties, strength; microstructural properties: porosity/permeability, pore pressure) as well as operational properties (borehole fluid pressures, flow rates, viscosity). Thus far, wireline mini-fracture tests experienced mixed successes pointing to a need to better predict the expected failure conditions of the formations before application of the wireline dual-packer mini-fracture jobs.

A novel simulator was developed that combines all main parameters (stress conditions, geomechanical & rock properties and operational parameters) controlling the performance of a mini-fracture job and the conditions at which tensile failure should occur near the wellbore. Sensitivity analyses with the simulator showed that rock permeability has the largest influence on the flow rates and fluid-pressure build-up over time. Geomechanical properties as the Young Modulus and Poisson's ratio have a large effect on the fluid pressures needed for tensile failure. Tool specifications determine the maximum fluid pressures that can be reached. The combination of these parameters determines ultimately the possible success or failure of the mini-fracture testing job. The developed simulator can be used to predict the conditions at which tensile failure is expected and can then guide and be compared with actual field tests.
Sand Control in Shallow Unconsolidated Sandstone Oil Reservoirs at Staatsolie N.V. Suriname
Authors: Toelsie S. , Goerdajal P.
Published: June 2013

Hydrocarbon production from unconsolidated sand reservoirs requires sand control usually consisting of the installation of a screen combined with gravelpacking. Several existing criteria such as Tiffin, Saucier and Coberly can be used for optimal selection of the sand control design. Sand and fines production in oil and gas wells are one of the main challenges and can result in failures of production systems. Especially in unconsolidated sand reservoirs, proper sand control practices are required to prevent reservoir sand production. At Staatsolie sizing of sand control design is based on the Saucier method incorporating the results of reservoir sand particle size distribution of side wall core samples.

A Staatsolie-Suriname in-depth research of sand control practices in shallow, low-pressure, heavy-oil unconsolidated sand reservoirs completed with progressive cavity pumps will be presented. The conventional sand control method applied is the installation of formation sand sized wire wrapped screens and gravelpack completion on uniform and non-uniform distributed reservoir sands. Stand alone screen completions have revealed its application in uniform distributed reservoir sands. Sand production and control on depleted and complex reservoirs based on the conventional method has become a major challenge. In Suriname, in three onshore fields approximately 1,500 wells are completed and are in production. With improved sand control practices, failures have been reduced to less than 5 wells per year.

The study has demonstrated the challenges and benefits of sand control in these complex unconsolidated Tertiary reservoirs. This has resulted into increased production and economic benefits. Results of lab tests and field cases will be presented and recommendations will be given on the best approach for sand control practices and the most cost effective sand control solutions in unconsolidated shallow sand reservoirs.
Significant Increase in Sand Control Reliability of Open Hole Gravel Pack Completions in ACG Field - Azerbaijan
Authors: Susilo Yoliandri , Whaley Kevin , Loboguerrero Santiago , Jackson Phillip , Kerimov Natig , Anderson Robert , Keatinge Patrick , Edment Brian
Published: June 2013

Azeri-Chirag-Gunashli (ACG) is a giant field located in the Caspian Sea, Azerbaijan. The major reservoir zones are Pereriv sandstone formations with 20–25% porosity, permeability 100–1000md, and oil column up-to 1000m. These formations are weakly consolidated where Open Hole Gravel Pack (OHGP) completions have become the standard design for production wells. Development began in 1997 and to date more than 70 high rate (up to 45mbd per well) OHGPs have been installed.

Wellbore stability issues require OHGP screens to be run in Oil Base Mud (OBM). Despite excellent initial success a number of sand control failures began to occur in 2008. A detailed gravel pack evaluation using multiple wash pipe gauges have revealed that earlier installations experienced screen plugging on lower section during the installation process. This leads to an incomplete pack in the toe area and subsequent screen failure as depletion increases or once water breakthrough occurs. The ultimate risk is of lost production rather than well control or loss of containment.

Analysis was done to understand the root causes of screen plugging and to develop solutions for each. The work resulted in five key changes being made to the OHGP completions.

○ Revised TD criteria for the open hole section. ○ Modified OBM conditioning procedures. ○ Modified wellbore-clean-out procedures. ○ A modified screen BHA design. ○ The use of Ultra-Fine-Grain Barite in the OBM to reduce barite sag and the amount of large solids in the fluid system.

These changes have resulted in less screen plugging, and hence increasing pack efficiency across the productive interval. This has resulted in a step change in OHGP reliability in the last 3 years with zero sand control failures over the last 24 completions. The detailed understanding of the failure mechanism also facilitated a successful intervention campaign to remediate several failed OHGP wells pre 2008. These efforts have delivered ~60mbd reduction in production losses over the past 2 years.
Characterization of Renal Glucose Reabsorption in Response to Dapagliflozin in Healthy Subjects and Subjects With Type 2 Diabetes
Authors: DeFronzo Ralph A. , Hompesch Marcus , Kasichayanula Sreeneeranj , Liu Xiaoni , Hong Ying , Pfister Marc , Morrow Linda A. , Leslie Bruce R. , Boulton David W. , Ching Agatha , LaCreta Frank P. , Griffen Steven C.
Published: June 2013

OBJECTIVE

To examine the effect of dapagliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, on the major components of renal glucose reabsorption (decreased maximum renal glucose reabsorptive capacity [TmG], increased splay, and reduced threshold), using the pancreatic/stepped hyperglycemic clamp (SHC) technique.

RESEARCH DESIGN AND METHODS

Subjects with type 2 diabetes (n = 12) and matched healthy subjects (n = 12) underwent pancreatic/SHC (plasma glucose range 5.5–30.5 mmol/L) at baseline and after 7 days of dapagliflozin treatment. A pharmacodynamic model was developed to describe the major components of renal glucose reabsorption for both groups and then used to estimate these parameters from individual glucose titration curves.

RESULTS

At baseline, type 2 diabetic subjects had elevated TmG, splay, and threshold compared with controls. Dapagliflozin treatment reduced the TmG and splay in both groups. However, the most significant effect of dapagliflozin was a reduction of the renal threshold for glucose excretion in type 2 diabetic and control subjects.

CONCLUSIONS

The SGLT2 inhibitor dapagliflozin improves glycemic control in diabetic patients by reducing the TmG and threshold at which glucose is excreted in the urine.
Occupational Exposure to Respirable Crystalline Silica in the Iranian Mazandaran Province Industry Workers
Authors: Mohammadyan Mahmoud , Rokni Mohammad , Yosefinejad Razieh
Published: June 2013

This study investigated occupational exposure to silica dust of 48 workers in stone cutting, glass making, ceramic, and sand blasting plants in the north of Iran. Samples were collected from the breathing zone using a personal sampling pump and a size-selective cyclone. Sample filters and blanks were analysed using infrared spectroscopy. The mean sampling period was 4.83 h. Mean exposure of workers to crystalline silica dust in glass making, ceramic, sand blasting, and stone cutting was 0.129 mg m-3, 0.169 mg m-3, 0.313 mg m-3 and 0.318 mg m-3, respectively. As exposure at each of the workplaces is three to 12 times higher than the current national and international thresholds, these workers run a greater risk of lung cancer and mortality. Our findings call for specific ventilation design and personal protection improvements in the four plants as well as stricter enforcement of the existing regulations by the authorities.
Effect of Ti, Nb, Cr and B on Structure and Mechanical Properties of High Aluminium Cast Iron
Authors: Kopyciński D.
Published: June 2013

In this work, a method was investigated to eliminate the presence of undesirable Al4C3 phases in a high-aluminium alloys, and thus improve the production process. The melting conditions employed in this work enabled the formation of a Fe-Al-C liquid solution. Moreover, titanium additions into the liquid allowed the precipitation of TiC. According to this reaction, the extent of carbon removal from the melt is strongly influenced by the amount of Ti additions. Hence, proper titanium levels can result in total removal of carbon from the liquid. Notice from this figure that Ti additions above 4.5%, totally eliminate the undesirable Al4C3 precipitates. Making Cr, Ti, B additions reduces size of FeAl alloys grains. In addition, this work indicates that the high-aluminium cast iron posses high oxidation resistance, exceeding that of high-chromium cast iron and chromium cast steels. Finally, the alloy ductility can be enhanced by additions of dopants such as B and Cr. Hence, additions of 0.03% B and 0.03%B-5% Cr combined with a heat treatment were implemented. As a result, the alloy ductility was significantly improved, where the strain of up to 5.3%, (B alone) or 15% (B-Cr) were obtained.
Some applications of weighing designs
Authors: Graczyk Małgorzata
Published: June 2013

The purpose of this paper is to apply results on weighing designs to the setting of 2m factorial designs. Using weighing designs, we give some proposals for experimental plans. Relevant counterexamples are indicated. Also the results of a simulation study on the existence of weighing designs are presented.
The relation between GxE interaction and the number of locations in series of oilseed rape trials
Authors: Pilarczyk Wiesław
Published: June 2013

The problem of the selection of locations (experimental stations) for experiments on oilseed rape is considered. The results of 138 experiments conducted by the Research Centre for Cultivar Testing (COBORU) in the period 2006-2010 at 41 experimental stations form the basis for all considerations. The method applied earlier by Pilarczyk and Fraś (2007, 2010) for analysis of similar results concerning winter wheat was utilized here. However, because of the high degree of non-orthogonality of the data (slightly overlapping sets of varieties among years) only analyses of single-year series were possible. The locations with a high contribution to the genotype-environment interaction were identified.
Numerical Analysis for Two-phase Flow in Porous Media
Authors: Chen Zhangxin
Published: June 2013

In this paper we derive error estimates for finite element approximations for partial differential systems
which describe two-phase immiscible flows in porous media. These approximations are based on mixed finite element
methods for pressure and velocity and characteristic finite element methods for saturation. Both incompressible and
compressible flows are considered. Error estimates of optimal order are obtained.
Error Bounds for Finite Element Methods with Generalized Cubic Splines for a 4-th Order Ordinary Differential Equation with Nonsmooth Data
Authors: Zlotnik A. , Kireeva O.
Published: June 2013

A boundary value problem for a 4-th order self-adjoint ordinary differential
equation is considered in the case where the coefficients of the equation and its
right-hand side can be nonsmooth (discontinuous, concentrated or rapidly oscillating
functions). Generalized cubic splines of deficiency 1 depending on the major coefficient
of the equation are applied. An error analysis of finite element methods exploiting such
splines is presented in detail including superconvergence error bounds. .
Influence of the Botanical Origin of Honey from North Western Spain in Some Antioxidant Components
Authors: Escuredo Olga , Fernández-González María , Rodríguez-Flores María S. , Seijo-Rodríguez Ana , Seijo-Coello María C.
Published: June 2013

Honeys were studied in order to know the relationships between their botanical origin, the total content of phenols and flavonoids, and the 2.2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The principal floral resources for honeybees in the studied area were Castanea sativa, Rubus, Eucalyptus, Erica, and Cytisus.

Results showed the influence of Erica and Castanea in the phenol content, flavonoids content, and the antioxidant activity of honeys. The presence of Erica in honeys was related to the highest phenol content; so heather honeys had a mean content of 178.9 mg/100g. Honeys with high Castanea pollen content had the highest value of flavonoids (7.7 mg/100g) and a minor value of half maximal inhibitory concentration (IC50) (9.4 mg/ml). Eucalyptus and blackberry were the honeys with minor contents of these compounds. A stepwise linear regression was used to estimate the phenol content of honeys. The contribution of Erica and Castanea was highlighted in the obtained model (R2 = 0.61), with significant p-value (< 0.01).
Andrena Florivaga Eversmann , 1852 (Hymenoptera: Apoidea: Andrenidae) - A New Bee Species of the Genus Andrena in Poland
Authors: Banaszak Józef , Motyka Ewelina , Szczepko Katarzyna
Published: June 2013

The first record of Andrena florivaga Eversmann, 1852 is reported from Poland on the basis of specimens collected in the Kampinos National Park (Mazovian Lowland). Diagnosis, data on localities, biology, and general distribution of the species are provided. One female and five males were caught on a mowed fresh meadow and fallow fields with the use of water pan-traps (Moericke traps), during the 2003 - 2004 time period. The main morphological characteristics distinguishing Andrena florivaga from the very similar Andrena dorsalis Brullé, 1832 species and from the other species of the subgenus Lepidandrena are: in the case of females - the width of facial foveae and colouration of legs, and in the case of males - the length of the first flagellar segment, colouration of clypeus, and pubescence of gonostyles. Andrena florivaga can be found from France in the west, to Central Siberia (Baikal lake region) in the east, and Turkey in the south. Poland is the northernmost locality of the species.
Expression of Sir2, Hdac1 and Ash2 in Honey Bee (Apis Mellifera L.) Queens and Workers
Authors: Guan Cui , Zeng Zhi Jiang , Wang Zi Long , Yan Wei Yu , Pan Qi Zhong
Published: June 2013

The queen and worker bees have the same genetic makeup. However, the queen differs dramatically from the workers in anatomy, physiology, behavior, and lifespan. Three genes (sir2, ash2, and hdac1) have been shown to be associated with histone methylation and acetylation as well as longevity in worms and flies. The relative expression level of these genes was examined in the heads of queens and workers at different developmental stages. The sir2, ash2, and hdac1 expression levels in newly emerged queens, egg-laying queens, and egg-laying workers were significantly higher than those in newly emerged workers, nurses, and foragers. We conclude that these genes are possibly “queen-like” genes.
Compact Energy Measuring System for Short Pulse Lasers
Authors: Barna A. , Földes I. B. , Gingl Z. , Mingesz R.
Published: June 2013

In experiments with short-pulse lasers the measurement control of the energy of the laser pulse is of crucial importance. Generally it is difficult to measure the amplitude of the pulses of short-pulse lasers using electronic devices, their response time being longer than the duration of the laser pulses. The electric response of the detector is still too fast to be directly digitized therefore a peak-hold unit can be used to allow data processing for the computer. In this paper we present a device which measures the energy of UV short (fs) pulses shot-byshot, digitizes and sends the data to the PC across an USB interface. The circuit is based on an analog peak detect and hold unit and the use of fiber optical coupling between the PC and the device provides a significant improvement to eliminate potential ground loops and to reduce conductive and radiated noise as well. The full development is open source and has been made available to download from our web page (http://www.noise.inf.u-szeged.hu/Instruments/PeakHold/).
Life After a Sports Career: the Case of Polish Ex-fencers
Authors: Kucharska Agata , Witold Kłopot Stanisław
Published: June 2013

The present study focuses on the issue of the achievement of stability in life by former amateur fencers in the context of post-communist Polish society. The main aim of the study was an analysis of non-sport spheres of life of former fencers, such as occupation, material situation, family life, and health. The sample consisted of 51 former Polish fencers. A diagnostic survey was conducted with the use of the questionnaire technique. It was revealed that the subjects successfully achieved social stability after they retired from sports. However, since they had been amateur athletes, they had been forced to choose appropriate strategies and actions during their sports careers to ensure professional, economic, and family stability in their future lives. Those who experienced difficulties in combining the role of athlete with other social roles were most often forced to give up fencing. The former fencers observe a multidirectional impact of sports on all aspects of their lives.
Analysis of Changes in Prices of Land in the Vicinity of National Roads
Authors: Radziszewska Wioleta , Jaroszewicz Joanna
Published: June 2013

Over the last several years, Poland has experienced dynamic development of linear infrastructure, mainly regarding national roads. The changes are reflected in the condition of the market of land located in the vicinity of newly constructed roads. The location of a property in the vicinity of an express road junction offers more convenient access to the labour market or sales market. On the other hand, possible negative effects include increased noise and pollution, as well as spatial continuum disturbance.

The objective of the study is the analysis of the effect of national roads on the development and dynamics of changes in prices of land in their vicinity. The estimation of the dynamics of such changes permits the determination of the stage of implementation of investments involving the highest variations of property prices. The analysis was conducted based on the following criteria: class of national roads (motorway or main express road) and the size of the urban centre located on route. The study involved the application of the Geographic Information Systems technology ArcGIS ESRI, data from the register of property prices and values, and cadastre information included on websites iGeoMap and Geoportal.
The Effects of Caffeine on Repeated Sprint Performance in Team Sport Athletes – A Meta-Analysis –
Authors: Brown Stephen J. , Brown Julie , Foskett Andrew
Published: June 2013

Equivocal findings exist regarding the ergogenic effects of caffeine in repeat sprint performance in team sports, and there is currently no meta-analysis of available data. Therefore, appropriate studies were obtained from electronic databases following identification using pre-determined search criteria. Extracted data on repeat sprint performance in team sport athletes were entered into a meta-analysis to determine a summary statistic for overall effect. Eight studies provided suitable data for analysis. Pooled data on sprint distances of 15m (Z=1.81, P=0.07), 18.3m (Z=0.26, P=0.79), 20m (Z=0.13, P=0.90), 30m (Z=1.26, P=0.21), and 36.6m (Z=0.78, P=0.44) indicated no ergogenic effect attributable to caffeine ingestion. Thus, the current available evidence does not support an ergogenic effect for caffeine in repeat sprint performance in team athletes.
A Study on the Relationship Between Sports and Aggression
Authors: Oproiu Ioana
Published: June 2013

Aggression is a general feature of human beings, a potential condition which can be activated fast or slow and it may take various forms of manifestation. In sports, where the main characteristic is the competition itself, the essential coordinates of the existence are: rivalry, direct confrontation with the opponents, desire to win and optimal activation. Today, the increasing number and frequency of aggressive acts occurring on or around the sports ground, makes us wonder where or which are the limits of combativity. This situation also demands a good understanding of deep psychological connotations of such behaviors. This paper is first of all a review of the most important theories of aggression shaped over the time. Also, we mention some of the most relevant studies on the issue of aggression in sport. The research is based on social learning theory developed by Albert Bandura. For that purpose, it was developed a comparative analysis of the results obtained from 106 football players who completed a specific questionnaire for assessing hostility. There are significant differences between the index of anger expression specific to the age of 17-18 years and the one specific to the athletes with 14-15 years
The Art of Goal Setting: A Tale of Doing Sport Psychology in Professional Football
Authors: Larsen Carsten Hvid , Engell Christian
Published: June 2013

The presence of sport psychologists in football is still a recent occurrence and has come about thanks to the improved education received by the coaching staff. However, sport psychology in football is still viewed upon with skepticism, as problem solving. One of the most common psychological strategies is goal setting. Nowadays it is hard to imagine clubs or players who do not use such strategies. In general, the correct application of goal setting principles provides a strong foundation for designing a goalsetting program. Nevertheless, there is a difference between the “science” of setting goals, and the ability of the sport psychologist practicing the “art” and process of setting goals. This case study involved four professional football players, from a team in the highest league in Denmark. We collected data through questionnaires, interviews and observations during a year. The results shows, that the “art” of goal setting is a dynamic, ever changing, complex phenomenon, the method itself has to be flexible, in order to search for new knowledge in a goal setting process in sport psychology consulting underlining that the individual sessions and success is socially constructed and created between sport psychologist and player.
Ethics of Officials in the Context of (Slovene) Good Administration
Authors: Kovač Polonca
Published: June 2013

The author discusses various aspects of ethical conduct, referring to both individual officials and the public administration as a whole, in the sense of good governance. She underlines that the main ethical challenge for officials (seen as executors of public tasks) is to be responsive to the needs of the society in any type of activity falling within the competence of administrative bodies, such as designing new regulations and deciding on specific administrative matters. Considering the significance of public administration for the development of the society, the foundations of ethical conduct of officials are largely defined already in administrative law. The work of the officials is not mechanistic but rather involves the creation of law - although at a purely instrumental level - and is therefore responsible and ethically determined. Officials fulfil their mission as long as they act lawfully within the scope of their powers and comprehend the purpose of law, which is to protect general social benefit and public interest, together with human or legally protected rights and individual interests. Within the limits of their powers and regulations, they are called to solve life issues. Thus, they contribute to democratic and effective administration. The paper provides an analysis of selected aspects, dilemmas and practices arising at the level of individuals and the Slovene administrative system as a whole, at the intersection between work ethics, administrative law and good public administration. In terms of legal principles and ethical codes, Slovenia is considered a rather successful European country; nevertheless, in order to raise general awareness and put the officials’ ethics in practice, a more proactive approach to governance and management is needed.
Agencies in Three South Eastern European Countries: Politics, Expertise and Law
Authors: Koprić Ivan , Kovač Polonca , Musa Anamarija
Published: June 2013

Agencies are an organisational form with regulatory, expert or executive tasks that may ensure better usage of expertise compared to traditional administrative organisations. However, there are certain unintentional effects of the agency model, which are more obvious in transitional countries. Coordination and policy coherence gaps may raise the question of political accountability, provoke robust political interventions, and undermine the level of autonomy and expertise, especially where a firm legal framework does not limit the influence of politics. Another problem is the effective legal control over agencies. Traditional, bureaucratic legal procedures of internal control and courts’ supervision in certain transition countries, like those researched in the paper (Slovenia, Croatia and Montenegro), are not fully suitable and effective for agencies, opening significant room for politicisation hidden behind expertise. The recent proliferation of agencies in those countries causes many new problems of public administration and enhances old ones. Interview-based research conducted in three countries in January 2012 has the purpose to establish the main problems and issues in the functioning of agencies, especially with regard to the legal aspect of agency and politics / policy relations. Basic findings confirm the hypothesis that the agency model in those countries has not been stabilised yet. Professionalism, autonomy and expertise of the agencies are in a precarious position. The legal framework for agencies should be fine-tuned and strengthened, to ensure proper steering within the agency model.
He Who Appoints the Piper: Understanding Reasons and Implications of Agency Management “Politicisation” in Slovakia
Authors: Beblavy Miroslav , Sicakova-Beblava Emilia , Ondrusova Darina
Published: June 2013

Summary / Abstract

Discussion of politico-administrative relations as well as the research on agencies generally treats the “politicisation” of agency management as a single, “black-box” concept, according to which agency managements (and other senior civil servants) are either political or not. Our paper shows that, using a strict, but widely applied definition of what constitutes a political appointment, agency heads in Slovakia are overwhelmingly “political”, but that the implications of politicisation vary, depending on the type of politicisation. In particular, we distinguish personal nominations of the responsible minister and contrast them with party nominations based on coalition agreements. Based on a series of interviews with senior policy-makers on both sides of the politico-administrative divide, we show that the selection mechanism, incentive structure and robustness of actual accountability mechanisms differs more between these two types of politicisations than between the ministerial and formally “non-political” appointment.
On almost nearly continuous functions with reference to multifunctions
Authors: Rychlewicz Andrzej
Published: June 2013

We deal with a new kind of continuity of multifunctions, namely almost nearly quasi-continuous multifunctions have been introduced. Several properties of almost nearly quasi-continuous and almost upper (lower) nearly quasicontinuous multifunctions have been obtained.
Some continuous operations on pairs of cliquish functions
Authors: Grande Zbigniew , Strońska Ewa
Published: June 2013

The algebraic or lattice operations in the classes of cliquish or quasicontinuous functions are well known [Z. Grande: On the maximal multiplicativefamily for the class of quasicontinuous functions, Real Anal. Exchange 15 (1989-1990), 437-441, Z. Grande, L. Soltysik: Some remarks on quasicontinuousreal functions, Problemy Mat. 10 (1990), 79-86]. This also pertains to the symmetrical quasicontinuity or symmetrical cliquishness [Z. Grande: On the maximaladditive and multiplicative families for the quasicontinuities of Piotrowskiand Vallin, Real Anal. Exchange 32 (2007), 511-518]. In this article, we examine the superpositions F(f, g), where F is a continuous operation and f, g are cliquish (symmetrically cliquish) or f is continuous (f is symmetrically quasicontinuous with continuous sections) and g is quasicontinuous (symmetrically quasicontinuous).
Pathogenesis and Assessment of Renal Function in Patients With Liver Cirrhosis
Authors: Teneva Bilyana H.
Published: June 2013

In liver cirrhosis patients awaiting liver transplantation, it is prognostically equally important to assess the renal function before and after transplantation. This is evidenced by the inclusion of serum creatinine in the Model for End-Stage Liver Disease (MELD) score. Most of the causes of renal failure in liver cirrhosis are functional, the acute kidney damage including prerenal azotemia, acute tubular necrosis and hepatorenal syndrome. A major index of the renal function, the glomerular filtration rate (GFR) is determined in a specific way in patients with liver cirrhosis. Clinically, serum creatinine is considered the best indicator of kidney function, although it is rather unreliable when it comes to early assessment of renal dysfunction. Most of the patients with liver cirrhosis have several concomitant conditions, which are the reason for the false low creatinine levels, even in the presence of moderate to severe kidney damage. This also holds for the creatinine clearance and creatinine-based estimation equations for assessment of the glomerular filtration rate (the Cockroft-Gault and MDRD formulas), which overestimate the real glomerular filtration. Clearance of exogenous markers is considered a gold standard, but the methods for their determination are rather costly and hard to apply. Alternative serum markers (e.g., cystatin C) have been used, but they should be better studied in cases of liver cirrhosis assessment.
Ansätze zur Senkung der Holzerntekosten in der Schweiz
Authors: Bürgi Patric , Pauli Bernhard
Published: June 2013

Approaches to reducing timber harvesting costs in Switzerland

For over two decades, the majority of Swiss forest enterprises have been confronted with financial losses. One of the main reasons for this is the general diminishing of revenues from timber sales since the 1980s. Moreover, Swiss forest enterprises have not managed to reduce the most important matter of expenses – the timber harvesting costs – to a similar extent. In comparison, unit costs from timber harvest in Switzerland are more than twice as high as those in the neighboring countries. This study analyzes the cause-and-effect relationships that lead to the high timber harvesting costs in Swiss forest enterprises. Building on that, possibilities of reducing these costs are proposed. The study is based on the results obtained through the Swiss Forestry Holding Network (HDN). The results have been systematically analyzed, the cause-and-effect relationships graphically depicted, and the gained knowledge has been discussed with experts. In essence, the results from the HDN suggest that the high timber harvesting costs are primarily a consequence of the structural situation of the Swiss forest enterprises. The over-proportionally high number of employees and large machinery parks allocated to each of the management areas are inevitably leading to high timber harvesting costs, and thus to suboptimal timber harvesting methods. Subsequently, this is all giving rise to an unfavorable cost situation. Furthermore, economies of scale can hardly be reached among the large numbers of relatively small forest enterprise management areas producing low usage quantities. In essence, the most important approaches to reducing the timber harvesting costs are the more frequent involvement of specialized forest services for harvesting, and measures that lead to the enlargement of the management areas. In order to reduce timber harvesting costs and by that improve operation results, a critical reflection of the current forest management strategy is unavoidable.
Effect Of Combined Application Of Cattle Manure And Em On The Yield And Yield Components Of Groundnut (Arachis hypogaea L.)
Authors: Seran Thayamini H , Suthamathy N
Published: June 2013

The field experiment was conducted at the Eastern Region of Sri Lanka to evaluate the effects of cattle manure with EM soil application on the yield and yield components of groundnut (Arachis hypogaea L.) cv Indi. It consisted of 10 treatments replicated four times in a randomized complete block design. Treatments were five levels (0, 5, 10, 15 and 20 t/ha) of cattle manure (CM) with and without EM soil application. Air dry cattle manure was incorporated into soil two weeks before sowing and EM solution was sprayed to soil at two week intervals from flowering to maturity of the crop. All other agronomic practices were followed according to the recommendation. The results showed that the increase of cattle manure (up to 15 t/ha) combined with EM increased the number of pods, weight of pods and kernels per plant, 100-kernel weight, shelling % and total yield. Higher kernel yield (3.42 t/ha) was obtained from 15 t/ha CM + EM application. The kernel yield in the control treatment (chemical fertilizer only) was 2.78 t/ha, which was comparable to 2.81 t/ha of kernel with 15 t/ha CM application alone. This study revealed that cattle manure at the rate of 15 t/ha coupled with EM would give better yield of groundnut and it can replace chemical fertilizer use. Bangladesh J. Agril. Res. 38(1): 1-9, March 2013 DOI: http://dx.doi.org/10.3329/bjar.v38i1.15184
Studies On Genetic Divergence In Maize (Zea mays) Inbreds
Authors: Khan AA , Islam MR , Ahmed KU , Khaldun ABM
Published: June 2013

Genetic divergence in 17 CIMMYT Maize inbred lines including one check were assessed based on some morphological traits and grain yield using Mahalanobis D2-statistics. The experiment was carried out in alpha lattice design with two replications at Regional Agricultural Research Station, Ishurdi Pabna during the winter 2010-2011. The genotypes were grouped into four clusters. The cluster II contained the highest number of lines (6), while the cluster I contained only single genotype. The maximum inter-cluster distance was noticed between the cluster I and IV and minimum between cluster I and II. The highest intra-cluster distance was observed in the cluster IV and lowest in cluster I. The genotypes in the cluster III showed better performances having shorter growth duration, short stature, shortest ear height, better shelling percentage and reasonable yielding ability. It is expected that crossing of inbred lines belonging high to medium D2 values may tend to produce high heterosis for yield. Ear aspect had the greatest contribution to the genetic divergence. Days to pollen shedding, silking, maturity, and 1000-grain weight were found to be responsible for primary differentiation. Bangladesh J. Agril. Res. 38(1): 71-76, March 2013 DOI: http://dx.doi.org/10.3329/bjar.v38i1.15191