bluuebunny/crossref_metadata_2025 huggingface dataset:
Smart Well Completion Utilization to Optimize Production in MRC Well - A Case Study
Authors: Al-Khalifa Mohammad T. , Mishkhes Abdulrahman T. , Baruah Keshab N. , Al-Otaibi Nashi M.
Published: September 2013

Introducing smart completions was one of the most revolutionary events in the oil industry because it will lead to higher productivity index, longer life, increase in the sweep efficiency, better water management, and it is more cost-effective. Moreover, smart completion gives the company the ability of remote operation and more advances monitoring over the reservoir. Being a leader in the oil industry Saudi Aramco was one of the first companies to implement smart completions in their wells. The inflow control valve (ICV) and permanent downhole monitoring system (PDHMS) in addition to maximum reservoir contact (MRC) are all components of smart completion that are used by Saudi Aramco. Nowadays, smart completion wells are a major contribution in Saudi Aramco fields as they are used to enhance the reservoir sweep.

This paper will show a detailed case study that was done on a smart completion well drilled in a carbonate field. The well is producing from a thin zone and close to the water zone. Smart completion is used to optimize the well production, manage the water production, and prolong the well life. In this case study, multiple single lateral testing was performed on the well over a time interval of 2 years to monitor major changes. The test was made so as to have a better understanding of the water movement and how it can be managed and controlled. The well includes three laterals in addition to the motherbore. The results of those several tests will be shared in this paper, including steps done to maintain the production targets and to decrease water cut along with suggestions that can lead to better results and improve future production optimization tests.
Ensemble Machine Learning: The Latest Development in Computational Intelligence for Petroleum Reservoir Characterization
Authors: Anifowose Fatai A.
Published: September 2013

With the persistent quest for better prediction accuracies of petroleum reservoir properties, research in Computational Intelligence (CI) continues to evolve new techniques to meet this noble objective of petroleum reservoir characterization. In previous presentations, it was established that individual CI techniques are limited in their performance as they have their respective areas of strengths and weaknesses. The concept of Hybrid CI (HCI) was presented to overcome this problem as it utilizes the strengths of two or more techniques to compliment their respective weaknesses. However, the HCI techniques are not able to integrate the various expert opinions on the optimization of CI techniques and those that exist in their respective fields of application. The ensemble learning paradigm is presented here as a possible solution.

The ensemble learning paradigm, also called the committee of learning machines, is the latest development in Computational Intelligence and Machine Learning technologies. It is the method of combining the output of several individual learners with different hypotheses employed to solve the same problem in order to produce an overall best result. The success of this paradigm is based on the belief that the decision of a committee of experts is better than that of a single expert. The ensemble method has been successfully applied in other fields such as bio-informatics, hydrology, time series forecasting, soil science, and control systems. Its benefits have not been well utilized in petroleum engineering.

As a continuation of what has become like a "SPE Computational Intelligence Lecture Series" over the past 2 years, this paper presents an overview of the ensemble learning paradigm, a review of its successful application in other fields, a justification of its necessity in petroleum engineering and a general framework for its successful application in reservoir characterization. This paper will be of benefit to interested persons to explore the exciting world of computational intelligence and for the appreciation of the benefits of the latest development in computational intelligence.
Integrating Cultural and Mechanical Methods for Additive Weed Control in Organic Systems
Authors: Benaragama Dilshan , Shirtliffe Steven J.
Published: September 2013

Effective weed management strategies are limited in organic cropping systems because herbicide use is prohibited. Enhancing crop competitive ability by integrating both cultural and mechanical weed control methods is a key strategy in such instances, but the relative efficacy of different cultural and mechanical strategies and their interactions and additive effects when combined is not well known. The objective of this study was to determine the individual and additive effects of cultural and mechanical methods on weed suppression and crop yield under organic conditions. A study was performed in two organically managed oat (Avena sativa L.) cropping systems in Saskatoon, SK, Canada, in 2008 and 2009. Three cultural practices, two crop genotypes (competitive and less competitive), high and standard crop densities (500 and 250 plants m–2), narrow and standard row spacings (11.5 and 23 cm), and two post‐emergence tillage levels (harrowing and nonharrowed control) were factorially applied in a randomized block design. Increasing crop density and harrowing increased grain yield by 11 and 13%, respectively. Competitive genotype and high crop density reduced weed biomass by 22 and 52%, respectively. Combining high crop density with post‐emergence harrowing increased the grain yield by 25%. The combined treatment effects on weed biomass were more profound, as the competitive genotype, increased seeding rate, and post‐emergence harrowing decreased weed biomass by 71% compared with standard practices. Integrating cultural and mechanical weed management practices was superior to the use of individual practices because they additively control weeds in an organic cropping system.
Potential Nitrogen Source from Field Bean for Rainfed Mediterranean Cropping Systems
Authors: Sulas Leonardo , Roggero Pier Paolo , Canu Simone , Seddaiu Giovanna
Published: September 2013

Field bean (Vicia faba L. var. minor Beck) is cultivated in the Mediterranean basin in rotation with winter cereals for dry grain production for animal feed, green forage, hay, silage, or green manure. This study aimed to (i) quantify the field bean fixed N during 2 yr at two Italian locations under rainfed conditions, (ii) quantify the proportion of N and fixed N allocated by field bean to grain, straw, and recoverable roots, and (iii) estimate the potential contribution of field bean to the cropping system N balance. The mean N percentage derived from N2 fixation of field bean grain and straw was 76%, corresponding to 114 kg ha–1 of fixed N in the aboveground biomass. On average, field bean fixed 42, 12, and 9 kg N Mg–1 dry matter in grains, straw, and roots, respectively. Recoverable roots contributed <5% of the total plant fixed N, but estimates did not take into account rhizodeposition and fine root turnover. The net N balance was positive for green manure (117 kg N ha–1) and grain field bean without straw removal (31 kg N ha–1) but negative (–31 kg N ha–1) when straw was removed. The N gain vs. a non‐fixing species was 79, 62, and 117 kg ha–1 yr–1 for field bean used as grain without straw removal, grain with straw removal, and green manure, respectively. Our study indicated that field bean can play a significant role as a N source in rainfed cereal‐based cropping systems.
Fall‐ and Spring‐Applied Poultry Litter Effectiveness as Corn Fertilizer in the Mid‐Southern United States
Authors: Tewolde Haile , Sistani Karamat R. , Adeli Ardeshir
Published: September 2013

The effectiveness of fall‐ or winter‐applied poultry litter, relative to spring‐applied litter, as row crop fertilizer in the southern and southeastern United States has not been well researched. A 3‐yr field study was conducted in northern Mississippi to determine the effectiveness of litter as corn (Zea mays L.) fertilizer and quantify loss of its potency when applied in the fall. The grain yield and biomass of corn that received fall‐applied poultry litter (9 or 18 Mg ha–1) or 202 kg ha–1 NH4NO3–N was compared against that of corn that received the same fertilization treatments applied in the spring including an unfertilized control. Corn fertilized with 18 Mg ha–1 litter applied in the spring produced 24% less grain yield in the first year but up to 21% more grain yield in the last 2 yr than corn fertilized with spring‐applied NH4NO3. Unlike the common assumption that 50 to 65% of the total litter N is available in the same year of application, we estimated only 31% of the total N from 18 Mg ha–1 spring‐applied litter was available to corn in the first year. Applying 18 Mg ha–1 litter in the fall, relative to spring, reduced grain yield by 12.8% and biomass by 15.0% when averaged across the 3 yr. These results show that applying poultry litter in the fall in regions with warm fall and winter months similar to that of northern Mississippi reduces its value as a fertilizer and could potentially increase environmental risk.
Remote sensing of cyanobacterial blooms in Lake Champlain, USA
Authors: Trescott Adam , Isenstein Elizabeth , Park Mi-Hyun
Published: September 2013

The objective of this study was to develop cyanobacteria remote sensing models using Landsat 7 Enhanced Thematic Mapper Plus (ETM+) as an alternative to shipboard monitoring efforts in Lake Champlain. The approach allowed for estimation of cyanobacteria directly from satellite images, calibrated and validated with 4 years of in situ monitoring data from Lake Champlain's Long-Term Water Quality and Biological Monitoring Program (LTMP). The resulting stepwise regression model was applied to entire satellite images to provide distribution of cyanobacteria throughout the surface waters of Lake Champlain. The results demonstrate the utility of remote sensing for estimating the distribution of cyanobacteria in inland waters, which can be further used for presenting the initiation and propagation of cyanobacterial blooms in Lake Champlain.
Application of linear programming for looped water supply pipe network design
Authors: Sharma A. K. , Swamee P. K.
Published: September 2013

It has been indicated in the literature that looped water distribution systems designed with the linear programming (LP) optimisation technique are converted into tree-like structures resulting in the disappearance of the original geometry in the final design. Looped networks are provided for system reliability, thus such a design approach will defeat the basic purpose of looped systems provision. Such a limitation has hindered the application of LP for the design of looped water supply networks. A method for the design of a looped water distribution system has been developed such that the loop configuration of the network is maintained by bringing all the pipes of the network into the optimisation problem formulation using the LP optimisation method.
Turbidity as a surrogate for Cryptosporidium removal by filtration in drinking-water QMRA models
Authors: Bastos R. K. X. , Viana D. B. , Bevilacqua P. D.
Published: September 2013

A quantitative microbial risk assessment (QMRA) with Monte Carlo simulation was used to estimate risks of Cryptosporidium infection from drinking water. Four different approaches to assess Cryptosporidium oocyst removal by filtration were compared using three relationships between turbidity removal and oocyst removal proposed in the literature, and an empirical model based on oocyst log removal credits associated with filtered effluent turbidity. Using a large database of a full-scale water treatment plant in Brazil, two of the turbidity removal-based models returned 1–3 log unit removal of Cryptosporidium oocysts and median values of Cryptosporidium annual infection risk estimates of approximately 10−2pppy (per person per year). The other model based on turbidity removal and the empirical model resulted, respectively, in 2–3.5 and 0–4 log removal of Cryptosporidium oocysts and corresponding infection risk estimates around 10−2pppy, close therefore to the health-based targets of the WHO guidelines for drinking water. The results of this study indicate that the empirical model appears to be particularly suitable for QMRA studies and that similar models should be tested in other site-specific assessments of treatment performance.
Integration of on-line and off-line methodologies for the assessment of river water quality
Authors: Lopez-Roldan R. , Gonzalez S. , Pelayo S. , Piña B. , Platikanov S. , Tauler R. , de la Cal A. , Boleda M. R. , Cortina J. L.
Published: September 2013

Legislation related to water quality is becoming more stringent worldwide. A clear example is the Water Framework Directive (2000/60/EU) (WFD) that involves both a good chemical and biological status of water bodies. To achieve this good status advanced water quality monitoring platforms are needed. For that purpose, several detection technologies have been tested to evaluate their potential for river water quality assessment including on-line and off-line methodologies for measuring both chemical and biological status. The combination of these technologies has proved to be capable of detecting the presence of contaminants at low concentrations and sudden changes in water quality.
Evaluating Technology-Based Educational Interventions: A Review of Two Projects
Authors: Adamo-Villani Nicoletta , Dib Hazar
Published: September 2013

The article discusses current evaluation methodologies used to assess the usability, user enjoyment, and pedagogical efficacy of virtual learning environments (VLEs) and serious games. It also describes the evaluations of two recently developed projects: a virtual learning environment that employs a fantasy 3D world to engage deaf and hearing children in math- and science-based educational tasks, and a serious game for undergraduate students' learning of sustainable building concepts and practices. Although a growing body of evidence suggests that serious games and VLEs could be advantageous and beneficial as instructional tools, research focused on their role in educational settings still lacks a unified approach to evaluating these interventions. To address this gap, the article provides an overview of current challenges associated with assessing the effectiveness of serious games and VLEs. In addition, the results from two projects provide lessons learned, and are intended to guide future efforts in developing and evaluating similar educational technologies.
Growing Stem Students: How Late Nite Labs' Online Platform is Spreading Science and Saving Schools' Resources
Authors: Schwab Zoe
Published: September 2013

Although STEM represents one of the fastest-growing fields in today's workforce, the United States' higher education system is not producing enough qualified STEM graduates to fill the increasing need of these industries. Schools must find a way to engage students and keep them interested in these fields, but budget cuts, large classes, and the increasing number of non-traditional students has made this challenge more and more difficult. Additionally, with community colleges and technical schools comprising a greater percentage of STEM applicants than ever, there needs to be a viable option for these schools to engage students in active science learning while protecting their already limited resources. By creating an interactive lab environment accessed online, Late Nite Labs provides labs that are more accessible than ever. By offering safe, open-ended lab environments through a virtual platform, schools can offer diverse bodies of students a more comprehensive, exploratory science education.
The Daily Text: Increasing Parental Involvement in Education with Mobile Text Messaging
Authors: Pakter Alexander , Chen Li-Ling
Published: September 2013

Numerous educational researches have showed that parental involvement in schools is highly correlated with higher student performance (Griffith, 1996; Jeynes, 2005, 2012; Sheldon, 2003; Stevenson & Baker, 1987; Williams, & Sanches, 2012). The research results are so evident that schools are now required by law to implement parental involvement provisions in order to receive certain federal funds, such as No Child Left Behind Act of 2001. With the rapid advancement in technology, strategies to increase parental involvement in education have been moving from print formats to digital formats. This article is to investigate whether the use of text messaging via cell phones to communicate between teachers and parents has measurable results on the academic performance of students. The study results show that on its own, the use of text messaging does not significantly change student performance; however, texting may have other benefits to teachers and students.
Utility of Urine Eosinophils in the Diagnosis of Acute Interstitial Nephritis
Authors: Muriithi Angela K. , Nasr Samih H. , Leung Nelson
Published: September 2013

Background and objectives

Urine eosinophils (UEs) have been shown to correlate with acute interstitial nephritis (AIN) but the four largest series that investigated the test characteristics did not use kidney biopsy as the gold standard.

Design, setting, participants, & measurements

This is a retrospective study of adult patients with biopsy-proven diagnoses and UE tests performed from 1994 to 2011. UEs were tested using Hansel’s stain. Both 1% and 5% UE cutoffs were compared.

Results

This study identified 566 patients with both a UE test and a native kidney biopsy performed within a week of each other. Of these patients, 322 were men and the mean age was 59 years. There were 467 patients with pyuria, defined as at least one white cell per high-power field. There were 91 patients with AIN (80% was drug induced). A variety of kidney diseases had UEs. Using a 1% UE cutoff, the comparison of all patients with AIN to those with all other diagnoses showed 30.8% sensitivity and 68.2% specificity, giving positive and negative likelihood ratios of 0.97 and 1.01, respectively. Given this study’s 16% prevalence of AIN, the positive and negative predictive values were 15.6% and 83.7%, respectively. At the 5% UE cutoff, sensitivity declined, but specificity improved. The presence of pyuria improved the sensitivity somewhat, with a decrease in specificity. UEs were no better at distinguishing AIN from acute tubular necrosis compared with other kidney diseases.

Conclusions

UEs were found in a variety of kidney diseases besides AIN. At the commonly used 1% UE cutoff, the test does not shift pretest probability of AIN in any direction. Even at a 5% cutoff, UEs performed poorly in distinguishing AIN from acute tubular necrosis or other kidney diseases.
MHD flow and heat transfer for Maxwell fluid over an exponentially stretching sheet with variable thermal conductivity in porous medium
Authors: Singh V. , Agarwal Shweta
Published: September 2013

An analysis is made to study MHD flow and heat transfer for Maxwell fluid
over an exponentially stretching sheet through a porous medium in the
presence of non-uniform heat source/sink with variable thermal conductivity.
The thermal conductivity is assumed to vary as a linear function of
temperature. The governing partial differential equations are transformed
into ordinary differential equations using similarity transformations and
then solved numerically using implicit finite difference scheme known as
Keller-box method. The effect of the governing parameters on the flow field,
skin friction coefficient, wall temperature gradient (in prescribed surface
temperature case), wall temperature (in prescribed heat flux case) and
Nusselt number are computed, analyzed and discussed through graphs and
tables. The present results are found to be in excellent agreement with
previously published work [1,2] on various special cases of the problem.
Opportunities of solid renewable fuels for (co-)combustion with coal in power plants in Serbia
Authors: Radovanovic Predrag , Jovanovic Marina , Eric Aleksandar
Published: September 2013

In the process of accession to the EU, Republic of Serbia will be obliged to
achieve an appropriate share of renewable sources in primary energy
consumption in addition to control the emission of carbon dioxide in order to
comply with EU?s energy policy. In this paper the potential of the production
of the so called 'green electricity' from biomass and waste in Republic of
Serbia is shown with particular attention to the Electric Power Industry of
Serbia, as the largest potential producer of electricity from renewable
fuels. Based both on the available total quantity and heating value of
non-hazardous solid waste material (municipal and industrial), the
calculation of the total available energy potential of waste in the Republic
of Serbia (by regions) was performed for the state of the 2010th and the
projections of waste quantity growth until 2020th. Also, for the same time
period, the available amount of waste biomass suitable for (co)combustion
with coal was estimated, as the respective energy potential. The possible
energy effects of (co)combustion in power plants as well as reduced emissions
of CO2 with significant financial impact are demonstrated. Actually, this
paper demonstrates necessity and techno-economic justification (co)combustion
of renewable fuel with coal in thermal power plants in Serbia.
Thermodynamic performance evaluation of an air-air heat pipe heat exchanger
Authors: Kumar Mohan , Kaushik S.C. , Garg S.N.
Published: September 2013

In this paper, heat transfer analysis for an air-air heat exchanger was
experimentally carried out to find its thermal performance and
effectiveness. Air-air heat exchanger equipped with finned heat pipes was
considered for the experimentation. Mass flow rate of air was considered in
between 0.24 to 0.53 [kg/sec]. The temperature at the condenser side of the
heat pipe heat exchanger was kept constant at around 23 [?C] and at the
evaporator part it was varied from 88 to 147 [?C]. The performance of heat
pipe heat exchanger was evaluated at different mass flow rate of air, in
terms of effectiveness and compared with its corresponding value found by
theoretical analysis.
Three dimensional modeling of combustion process and emission formation in a low heat rejection indirect injection diesel engine
Authors: Jafarmadar S.
Published: September 2013

Higher heat losses and brake specific fuel consumption (BSFC) are major
problems in an indirect injection (IDI) diesel engine, which can be overcome
by means of low heat rejection (LHR) concept. This concept is based on the
approach of insulating of piston and liner of main chamber in IDI engine. At
the present work, the combustion process and emission formation in baseline
and LHR engines are studied by a Computational Fluid Dynamics (CFD) code at
four different loads (25%, 50%, 75% and 100%) in maximum torque engine speed
730rpm. The numerical results for the pressure in cylinder and emissions for
baseline engine at full load operation are compared to the corresponding
experimental data and show good agreement. The comparison of the results for
two cases show that when the load increases from 25% to 100% in 25% steps,
heat loss in LHR engine decrease 40.3%, 44.7%,44.6% and 45.2%, respectively.
At full load operation in LHR engine, NOx and Soot emissions decrease 13.5%
and 54.4%, respectively and engine efficiency increases 6.3% in comparison to
baseline engine.
Does Reading Case Responses and Using Graphic Organizers Enhance Accounting Students' Case Analyses?
Authors: Phillips Fred , Nagy Alecia
Published: September 2013

This study investigates whether reading case responses and using graphic organizers can assist students in developing case analysis skills, such as identifying supporting arguments and counterarguments in analyses of financial accounting policy choices. The results of an experiment indicate that students who studied an exemplar case response were better able to identify supporting arguments in a subsequent case analysis. In contrast, students who used a graphic organizer to visualize elements of the exemplar case response were better able to identify the absence of counterarguments, which provide support for alternative accounting choices, in a subsequent case analysis. The effects of these pedagogical tools were apparent not only when students evaluated others' case analyses, but also when they generated their own analyses of a subsequent case. These results are significant because they suggest that short (11-minute) instructional interventions can encourage students to adopt two key aspects of critical thinking: identifying and generating relevant arguments and counterarguments.

Data Availability: The data and experimental materials used in this study are available on request from the corresponding author.
Technical Efficiency in the Use of Health Care Resources: A Cross-Country Analysis
Authors: Anton Sorin Gabriel
Published: September 2013

The aim of the paper is to assess the technical efficiency of twenty health systems from Central and Eastern Europe (CEE) and Commonwealth of Independent States (CIS). We used an outputoriented Data Envelopment Analysis (DEA) to measure the technical efficiency of the health systems using the latest data available on infant death and life expectancy as health outcomes. Our results show that technical efficiency varies across these health systems and this translates into potential savings of resources. The average efficiency scores for all heath systems were 0.98 for life expectancy at birth and only 0.821 for infant mortality. More than half of the health systems in the sample were technically inefficient in 2009 for both outputs. We found that 30% of national health systems were technically efficient for both outputs.
Interaction Between Marketing and Informational Technologies in the Insurance Business
Authors: Stofor Ovidiu
Published: September 2013

Business of selling insurance requires great skill especially in this time of difficulty caused by the economic crisis which seems to extend more than anyone had. If by 2008, life insurance offset the gap represented by a long-term savings product to fill in the state pension, after this year, more and more they entered the natural path of protection first. Currently, however, the economic crisis has become an even bigger reason to refuse or postpone the purchase of insurance.
A Frame Procedure for Multiple Criteria Selection of IT Products and Services
Authors: Čančer Vesna
Published: September 2013

In an information society, the Information Technology (IT) infrastructure of enterprises is important for their performance. Since in the last few decades the Multiple Criteria Decision Making (MCDM) methods have already turned out to be very applicable in solving problems, this article explores the particularities of the frame procedure for MCDM by using the group of methods based on assigning weights in the selection of IT products and services in enterprises. Special attention is given to the methods for establishing the judgements on criteria‘s importance, based on the interval scale. The procedure is completed for considering interactions - synergies and redundancies - among criteria, which can strengthen the decision making basis in the selection of the most appropriate IT product or service. The applicability of the above mentioned frame procedure is illustrated via a reallife case - the selection of the most appropriate storage array
The Dynamics of the Romanian Financial Reporting
Authors: Lapteş Ramona , Popa Adriana Florina
Published: September 2013

Accounting is the social science that developed and constantly improved in order to meet the information needed for each stage of the society evolution. In its turn, the financial reporting system was frequently reconsidered in order to harmonize the supply and demand for accounting information. The main objective of this study is to create a fresco of the financial reporting system in Romania, during the last two decades, which is intended to highlight the advantages and limitations of different accounting rules with direct impact on the financial communication process. The present situation demonstrates that the National strategy for improving the financial reporting of private economic entities, mostly based on drafting the individual annual financial statements of public interest entities in accordance with IFRS requirements, encountered certain difficulties in the implementation process.
Customer Satisfaction as a Marketing Concept in Higher Education
Authors: Andrlic Berislav , Budic Hrvoje , Pismis Vjekoslav
Published: September 2013

Measuring customer satisfaction is a very important aspect of marketing strategy. For the organizational's survival in the long run it is indisputable to have the ability to retain the customers. Retaining customers is more profitable than attracting new ones because it is easier to sell a product or service to a someone who has already used it, rather than someone to whom is product or service completely unknown. In order to measure customer satisfaction primary datas were collected using a test method on a sample of students, by a questionnaire in a physical form, analyzing the basic elements of educational process. Also, by researching relevant national and international professional and scientific literature the test method was described, and all of its models. Finally, in the conclusion, the basic thoughts about the paper are revealed through the presentation of practical advantages and disadvantages of marketing concept of satisfaction, and reviewing recent trends in communication with students.
Supporting Social Enterprises in the Context of Financial Effectiveness
Authors: Oliński Marian , Burchart Renata
Published: September 2013

The cooperative form of management is an essential part of the social economy. One of the most important elements in supporting social entrepreneurship is the problem of efficiency of different kinds of support. This paper presents an assessment of the effectiveness of social cooperatives in the traditional way, using the concepts and measures typical for-profit enterprises. The main objective of the research was to assess the effectiveness of financial aid, received by social cooperatives. The subject of the study were twenty social cooperatives, created from 2005 to 2010 in one of the Polish region (Warmia and Mazury). The study shows that there is some level of support, that allows to develop Polish social cooperatives.
Lifetime of a soluble solid particle in a stagnant medium: approximate analytical modelling involving fractional (half-time) derivatives
Authors: Hristov Jordan
Published: September 2013

Approximate analytical solutions concerning lifetime of soluble solid particles in an unbounded stagnant medium have been developed by simple application of fractional half-time derivative in the Riemann-Liouville sense to express the relationship between the net surface mass flux and the concentration at the interface. The solutions start with the initial formulation of Rice and Do on the time-depletion of the radius of a spherical particle expressed through terms including the solubility parameter as the only key parameter controlling the process of dissolution. The two approximate developed solutions use different scaling and dimensionless variables: The 1st solution is developed by an introduction of a similarity variable [xxx] while the 2nd solution applies the classical scaling using the initial sphere radius as a length scale that leads to dimensionless radius r = R/R0 and time τ = Dt/R0
2. Both solutions provide approximate relationships close to that of Rice and Do.
Complexation of poly(ethylene glycol) with poly(ethyl methacrylate-co-N-vinyl-2-pyrrolidone) gel based on hydrogen bonds
Authors: Liu Guoqin
Published: September 2013

The complexes of poly(ethyl methacrylate-co-N-vinyl-2-pyrrolidone) (P(EMA-co-VP)) gel with poly- (ethylene glycol) (PEG) stabilized by the hydrogen bonds were prepared. It was found that both the concentration and the molecular weight of PEG have a strong effect on the P(EMA-co-VP) gel. When PEG was introduced into the P(EMA-co-VP) gel, the glass transition temperatures (Tg) of the complexes decreases with the decreasing of PEG molecular weight. In such a system, the maximum molecular weight of PEG required for the complex formation is no more than 2000, and P(EMA-co-VP)/PEG complexes are a homogeneous amorphous phase, which was studied by FTIR, XRD, TEM, and DSC.
Effect of temperature on o-cresol methylation in a fluidized bed of commercial iron-chromium catalyst TZC-3/1
Authors: Berkowicz Gabriela , Żukowski Witold , Baron Jerzy
Published: September 2013

The paper presents the results of the synthesis of 2,6-dimetyhlphenol (26DMP) from o-cresol. The target compound is an important substrate for polymer chemistry. Due to a large amount of o-cresol which is generated as a by-product, during the synthesis of 2,6-dimethylphenol from phenol, the methylation of o-cresol to 2,6-dimethylphenol should be examined as a separate process. The alkylation of o-cresol was carried out in a fluidized bed of commercial iron-chromium catalyst TZC-3/1. Undesirable decomposition of methyl alcohol on the catalyst generates a number of environmentally dangerous by-products such as methane, carbon dioxide, carbon monoxide. The effect of temperature on the yield of the synthesis was investigated. The synthesis process was monitored on-line in the temperature range 310-380°C, completely covering the maximum efficiency of the process. Online analysis of the process by FTIR spectroscopy gave information about products of both methylation of o-cresol and pyrolysis of methanol. The maximum 85% yield of desired 2,6-dimethylphenol with more than 85% conversion of o-cresol was achieved at 340°C, at 1:6 molar ratio of o-cresol:methanol
Lignosulfonate and silica as precursors of advanced composites
Authors: Klapiszewski Łukasz , Nowacka Magdalena , Siwińska-Stefańska Katarzyna , Jesionowski Teofil
Published: September 2013

Advanced silica/lignosulfonate composites were obtained using magnesium lignosulfonate and silica precipitated in a polar medium. For comparative purposes analogous synthesis was performed using commercial silica Aerosil®200. Lignosulfonates are waste products of paper industry and their application in new multifunctional materials is of great economic interest. The composites obtained were subjected to thorough characterization by determination of their physicochemical, dispersive-morphological and electrokinetic properties. Their particle size distribution was measured, SEM images were taken, FT-IR analysis and colorimetric study were made, thermal and electrokinetic stabilities and parameters of porous structure were also determined. The results can be of interest in further application studies
General systems theory and the operation of basins without an outlet: A methodological aspect
Authors: Major Maciej
Published: September 2013

Basins without outlets, often with a small water body at the bottom, are a characteristic element of a postglacial landscape. Areas nourishing those small landforms belong to the passive part of catchments of hydrographic systems and determine the retentivity of entire drainage basins. The most suitable approach to adopt in research on those objects seems to be the theory of a geoecosystem, a universal methodological conception used in describing geographical regions at various scales. It allows the use of quantitative research methods, and hence parameterisation of their environment. Thus, the geoecosystems of basins without outlets can provide foundations of their dynamic classification.
The dynamics of macrophytes in a lake in an agricultural landscape
Authors: Sender Joanna
Published: September 2013

Macrophytes are a group of aquatic organisms affected by constant changes. One of the main factors influencing the rate and direction of these changes is the way of basin management. The aim of this study was to determine the effect of changes in the management of a lake catchment area in an agricultural landscape on the qualitative and quantitative structure of macrophytes and assessment of the ecological status of the lake in question. The study was conducted in the years 1996, 1999 and 2011 in Lake Głębokie Uścimowskie. This lake is small (20.8 ha surface) and shallow (about 6 m depth). In the 1990s in Lake Głębokie Uścimowskie from 14 to 15 plant communities occurred, which occupied 2.9 ha of the lake. This represented only 14.1% of the lake. In 2011 there was a slight growth in the number of phytocenoses (16), and significant increase in the area of phytolittoral - 5.98 ha. In the 1990s the range of ESMI index values, allowed the lake to be categorized as one with poor ecological status, but already in 2011 after a similar analysis, the lake was ranked in the upper limits of moderate ecological status of lakes. One of the main reasons for the rise in the ecological status of Lake Głębokie Uścimowskie, determined on the basis of the macrophyte index, as well as for the slight decline in trophy, was probably a sewerage system built in 2006 in Głębokie village.
Decoding and Reading Comprehension
Authors: García J. Ricardo , Cain Kate
Published: September 2013

The twofold purpose of this meta-analysis was to determine the relative importance of decoding skills to reading comprehension in reading development and to identify which reader characteristics and reading assessment characteristics contribute to differences in the decoding and reading comprehension correlation. A meta-analysis of 110 studies found a sizeable average corrected correlation ([Formula: see text] = .74). Two reader characteristics (age and listening comprehension level) were significant moderators of the relationship. Several assessment characteristics were significant moderators, particularly for young readers: the way that decoding was measured and, with respect to the reading comprehension assessment, text genre; whether or not help was provided with decoding; and whether or not the texts were read aloud. Age and measure of decoding were the strongest moderators. We discuss the implications of these findings for assessment and the diagnosis of reading difficulties.
A study of the clinical profile of atrial fibrillation in a tertiary care super-specialty referral centre in Central Nepal
Authors: Gautam MP , Gautam S , Prasad S Guru , Subramanyam G , Ghimire U
Published: September 2013

Background The conventional causes and risk factors for atrial fibrillation (AF) are somewhat arbitrary; overlap exists, multiple aetiologies are often present in one individual, and clinical presentation is non- specific. This study was an attempt to study the clinical and echocardiographic profile of patients with AF in a tertiary care super-specialty hospital of a developing country. Materials and Methods This study was conducted in College of Medical Sciences, Chitwan, Nepal throughout the year 2010. Subjects with AF, diagnosed based on clinical history, medical records and surface ECG, were included in the study. The presentation, types and causes of AF and structural as well as functional abnormalities were assessed. Results A total of 136 consecutive subjects were included in the study. The mean age was 42.40 (20.48) years ranging from 17 to 80 years. Majority of the AF subjects were female (54.41%). Among symptomatic cases, palpitation was the most common (23.53%) presentation followed by dyspnea (17.65%) and stroke or transient ischemic attack (15.44%). Asymptomatic presentation was also not uncommon (25%). Persistent AF was the most common form (31.62%). Rheumatic heart disease was the most common cause (33.09%) followed by lone atrial fibrillation (23.52%), coronary artery disease (16.18%), hypertension (8.82%) and thyrotoxicosis (7.35%). Other causes included chronic obstructive airway disease (5.88%), diabetes (2.94%), cardiomyopathy (1.47%), constrictive pericarditis (1.47%), myocarditis (0.74%) and infective endocarditis (0.74%). Nearly 65 % subjects had either structural or functional abnormalities in echocardiographic study; dilated left atrium was the most prevalent abnormality. Conclusion In contrast to the studies reported from developed nations, our subjects with AF were younger and female, the most common cause was RHD and the majority had either structural or functional abnormalities in echocardiographic study. Journal of College of Medical Sciences-Nepal, 2012, Vol-8, No-3, 9-16 DOI: http://dx.doi.org/10.3126/jcmsn.v8i3.8679
Study of variations in the pelvicalyceal system of kidney and its clinical importance
Authors: Wadekar PR , Gangane SD
Published: September 2013

Objective The present study has been undertaken to study the variations in renal pelvicalyceal system, to compare them with previous studies and to find their clinical implications. Materials and Methods A total of 100 kidneys (from 50 cadavers) were included in this study. The following parameters were measured 1)Lower Infundibular length, 2)Infundibular Width – Lower Infundibular Width (LIW), Middle Infundibular Width (MIW), Upper Infundibular Width (UIW), 3)Number of minor calyces and 4)Number of major calyces. Results The obtained data showed that there were numerous variations not only in the numbers of calyces of kidneys but also in the infundibular length and width. Conclusion Developments in endourology, percutaneous nephrolithotomy and techniques for retrograde percutaneous nephrostomy have rekindled interest in the anatomy of the renal collecting system. To perform these procedures safely and efficiently it is essential to have a clear understanding of pelvicalyceal anatomy and its variations. Thus the in-depth knowledge of pelvicalyceal anatomy will be of immense value to the clinicians of related specialties. Journal of College of Medical Sciences-Nepal, 2012, Vol-8, No-3, 17-21 DOI: http://dx.doi.org/10.3126/jcmsn.v8i3.8681
Phenotypic detection of extended spectrum ?-lactamase and AmpC ?-lactamase in urinary isolates of Escherichia coli at a tertiary care referral hospital in Northeast India
Authors: Bora A , Ahmed GU , Hazarika NK
Published: September 2013

Objective Urinary tract infections (UTIs) are the most prevalent infections worldwide, mostly caused by Escherichia coli. Emerging antibiotic resistance due to extended spectrum â-lactamase (ESBL) and AmpC β- lactamase production limit the use of β-lactam antibiotics against the infections caused by E. coli. We detected the production of ESBL and AmpC β-lactamase in urinary isolates of E. coli, recovered from a tertiary care referral hospital in Northeast India. Materials and Methods A total of 140 E. coli urinary isolates were recovered during October 2008 to January 2009. Antibiotic susceptibility testing and ESBL detection were carried out according to Clinical Laboratory and Standards Institute (CLSI) guidelines. Phenotypic detection of AmpC β-lactamase was carried out by AmpC disc method. Results Among the 140 urinary isolates, 112 isolates (80%) were multi-drug resistance (MDR). ESBL was detected in 67.14% (94/140) of E. coli isolates. AmpC β-lactamase was detected in 22.34% of ESBL producing E. coli isolates. Conclusions Routine testing for ESBL and AmpC β-lactamase in E. coli urinary isolates with conventional antibiogram would be useful for strict antibiotic policy implementation in hospitals, to estimate the impact of increased drug resistance and to take steps for reducing their resistance. Journal of College of Medical Sciences-Nepal, 2012, Vol-8, No-3, 22-29 DOI: http://dx.doi.org/10.3126/jcmsn.v8i3.8682
Management of acute peripheral arterial injury by using doppler ultrasonography
Authors: Chapagain D , Reddy DJ , Chadha SK , Agarwal S , Shrestha KG , Shah S
Published: September 2013

Objective To determine the effectiveness of the duplex ultrasonography scanning in the management acute peripheral arterial injury. Materials and methods Its a prospective evaluation comparing duplex scanning with operative exploration finding in 78 patients.Duplex scan was used alone for 98 patients having clinical finding of acute vascular insufficiency. Results Duplex scanning had 100% sensitivity and 95.23% specificity compared with operative exploration in the 78 cases. Duplex scanning detected 78 injuries, 77 of which were confirmed by correlation with operative exploration and 20 patients did not have vascular injury. One false-positive result was due to spasm of the superficial femoral artery. Conclusions Duplex scanning is a noninvasive, safe, effective , rapid and lesion localising method of initial evaluation for acute peripheral vascular injury having clinical features of vascular insufficiency. Journal of College of Medical Sciences-Nepal, 2012, Vol-8, No-3, 36-42 DOI: http://dx.doi.org/10.3126/jcmsn.v8i3.8684
The usefulness of ICG video angiography in the surgical treatment of superior cluneal nerve entrapment neuropathy
Authors: Kim Kyongsong , Isu Toyohiko , Chiba Yasuhiro , Morimoto Daijiro , Ohtsubo Seiji , Kusano Mitsuo , Kobayashi Shiro , Morita Akio
Published: September 2013

Superior cluneal nerve (SCN) entrapment neuropathy is a known cause of low back pain. Although surgical release at the entrapment point of the osteofibrous orifice is effective, intraoperative identification of the thin SCN in thick fat tissue and confirmation of sufficient decompression are difficult. Intraoperative indocyanine green video angiography (ICG-VA) is simple, clearly demonstrates the vascular flow dynamics, and provides real-time information on vascular patency and flow. The peripheral nerve is supplied from epineurial vessels around the nerve (vasa nervorum), and the authors now present the first ICG-VA documentation of the technique and usefulness of peripheral nerve neurolysis surgery to treat SCN entrapment neuropathy in 16 locally anesthetized patients. Clinical outcomes were assessed with the Roland-Morris Disability Questionnaire before surgery and at the latest follow-up after surgery.

Indocyanine green video angiography was useful for identifying the SCN in fat tissue. It showed that the SCN penetrated and was entrapped by the thoracolumbar fascia through the orifice just before crossing over the iliac crest in all patients. The SCN was decompressed by dissection of the fascia from the orifice. Indocyanine green video angiography visualized the SCN and its termination at the entrapment point. After sufficient decompression, the SCN was clearly visualized on ICG-VA images. Low back pain improved significantly, from a preoperative Roland-Morris Questionnaire score of 13.8 to a postoperative score of 1.3 at the last follow-up visit (p < 0.05). The authors suggest that ICG-VA is useful for the inspection of peripheral nerves such as the SCN and helps to identify the SCN and to confirm sufficient decompression at surgery for SCN entrapment.