bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Cutoffs and Implications in Integrated Reservoir Studies
Authors: Ebong Michael , Onyekonwu Mike
Published: July 2014

The building of 3D models from seismic, geological, petrophysical, well, drilling, reservoir and production engineering data which are used in the study of optimal recovery of hydrocarbons from petroleum reservoirs has become commonplace. During the static modeling phase of the workflow, there is the need for the application of limits on the petrophysical properties to differentiate reservoir from non-reservoir rock. These limits are called cutoffs: limiting values of petrophysical properties in the static models.

In this case study, multiple regression analysis was used to derive the best relationship of the form k = f(Ø, Vsh, Sw) which was then used to estimate optimum petrophysical cutoffs for the reservoir. Four static models of the reservoir were then built: the first model with only a Vsh cutoff of 0.42 to delineate reservoir rock from the non-reservoir rock. The other 3 utilized various Ø, Vsh and Sw cutoffs in their building. Four dynamic models of the reservoir were then built from the static models and were history matched to observed production and pressure data. Performance prediction was then carried out using the different history matched models. Finally, using the results of the forecast and other data, an economic analysis was carried out to determine the economic implications of the different cutoffs on the results of the studies.

The results showed that the values of the Ø cutoff affected the values of the corresponding Vsh and Sw cutoffs as well as those of the HCIIPs, with the general trend being that a reduction in the Ø cutoff increased the values of the Vsh and Sw cutoffs. The economic analysis showed that petrophysical cutoffs used in the development of the static (and the dynamic) models sure had some impact on the results of the analysis.
Ringfencing of Investment Spending and its Implications on the Profitability of Exploration and Production Projects
Authors: Babatola Awoniyi
Published: July 2014

Ringfencing is a common clause in the Production Sharing Contract (PSC) which implies that all costs and expenses related to the development and operation of a single reservoir, field or block, should be assigned and deducted from the revenues generated solely by that resource unit.

When certain costs are ringfenced, the probability of profitability of investments in frontier areas becomes slimmer.

Allowing exploration costs to cross a ringfence will impact more on the economic profitability of investment and promote further spending in the upstream business. This will act more as a stimulant for investors to explore such opportunities with the assurance that some successful play can compensate for losses during exploration.

The purpose of this paper is to evaluate the impact of ringfencing on profitability of an E&P asset and to show that allowing costs to cross a ringfence will be a strong incentive for the oil industry operators and would give some level of confidence that development of marginal fields would be economically viable. Such incentive proved to work in the UK in the early 1980s and 1990s. Allowing this incentive will show that the Host Government is willing to share E&P risk, reduce the degree of economic outcome uncertainty and creates an investment friendly environment for the operators.
Engineering Design and Calibration of Gas Metering Systems in Era of Increasing Product Cost
Authors: Ogwo O. U.
Published: July 2014

A new engineering design and calibration procedures for the natural gas metering system is presented that will enable the elimination of the over-sighted intrinsic errors in gas measurement, reduction to the barest minimum of the operational errors frequently incurred in the use of the flow meters, and resolution of the discrepancies between the various standards used in designing gas metering systems. As natural gas continues to gain prominence in the global energy mix and its price continues to appreciate, it becomes necessary (to take advantage of evolving technologies) to eliminate the systematic errors and minimize the random errors in gas measurement, the errors of which were hitherto considered insignificant in the face of calibration constraints. This paper explains why orifice flowmeters should now be calibrated online, emphasizes (using field and factory acceptance test (FAT) data) the need for online calibration of the new generation flowmeters even when equipped with self diagnostic mechanism, and presents the master prover selection procedure. The paper which is based on field experiences acquired over extended period of time during work visits to a number of gas fields in Nigeria, Europe and the United States of America, also reconciles the discrepancies existing between the two major standards (the AGA-3 and ISO 5167) used in the measurement of hydrocarbon gas.
Fracture Pressure Prediction Model for Deepwater Fields, Gulf of Guinea
Authors: Jenakumo Timipere D. , Itua Osazua J. , Ebimobowei Wodu K.
Published: July 2014

Following the 2010 Gulf of Mexico Macondo well control incidence, increased emphasis has been placed on the safe delivery of wells. Fracture pressure prediction is a critical input to effective well planning and safe drilling especially in deepwater environments due to rising well costs and narrower drilling margins with increasing water depths. Therefore, accurate formation fracture and pore pressure prediction is crucial to minimize potential borehole stability concerns, lost circulation problems and optimize casing setting depths during drilling. Also, for fields where water flooding is used to enhance recovery or maintain reservoir pressure, proper estimate of fracture pressure is necessary to curtail implications such as loss of production, injectivity and reputational damage in the event that there is loss of containment and hydrocarbons migrate through to surface.

This work establishes empirical correlations for fracture pressure prediction from field leak–off tests data; builds on existing foundations relating fracture pressure with overburden, in-situ effective stress ratio and pore pressure. The results indicate that the developed correlations can be suitably applied in offshore fields in the Gulf of Guinea deepwater environment.
Maximising Well Productivity through Appropriate Design of Cleanup Recipe and Proper Execution for New Well Completions
Authors: Olubamise Taiwo. O. , Oghene Ufuoma. J. , Uchendu Chinwe
Published: July 2014

Reduced productivity in newly completed wells could be attributed to impairments caused by drilling and completion operation activities which are caused mainly by the drilling and completion fluids and other additives that may have been used during these operations on the wells. However, in spite of these impairments, proper design and execution of well clean up post completion of the well is critical to ensuring that whatever debris left behind at the sand face completion is removed or reduced to improve and optimize the productivity of the wells. Designing the appropriate clean up recipe requires proper evaluation of the wells characteristics, conditions, reservoir properties, and the drilling and completions fluid including additives.

The clean up recipe design usually involves laboratory tests on mud samples from subject well, to determine the right content and quality of chemical that will properly dissolve the filter cake formed down hole.

Understanding the sand face completion type, well geometry and reservoir characteristics is a critical success factor to designing the placement of the recipe and achieving a successful well clean up. Effective placement of the designed treatment recipe is mainly done using coiled tubing. Whether to squeeze or jet across completion interval is subject to the well configuration.

In this paper, the Post clean up productivity of twenty-three (23) wells carried out in six (6) fields were reviewed to establish the relationship between the cleanup design, execution and productivity. Results of this shows that in the cases where proper design and execution of clean up were carried out, the wells productivity was successfully achieved as planned whereas in some cases of poor design and execution, the wells' performance was suboptimal.
Using Decision Algorithm to Optimise Development of a Gas Field with Limited Subsurface Data
Authors: Ogbalor Cyril , Osadjere Peter , Ebufegha Akpos
Published: July 2014

Evaluation of hydrocarbon recoveries from a field with limited geological, engineering, and geophysical data has a huge amount of uncertainty for each possible outcome. Understanding the implications probability of success (POS) of the sequence of events, can help managers make informed decisions on a field development strategy using a decision tree.

A decision tree, is a decision support graphical representation that uses a tree-like graph or model of decisions and their possible consequences, including chance event outcomes, resource costs, and utility. This, if effectively used can assist in making difficult decisions by reducing them to a series of simpler or less emotionally laden, choices.

This paper details, the results of the use of a Decision Algorithm for the optimization of a gas field development strategy with only one well drilled and no production data. The optimization was carried out following the re-interpretation of the seismic and well data, which resulted in a significant change in the structure and subsequent update in the static and dynamic characterization of the hydrocarbon bearing reservoirs.
An Excel Based Casing Design Application
Authors: Utsalo O , Olamigoke O , Adekuajo C. O
Published: July 2014

The Casing Design Application developed by well engineers in Havilah Hydrocarbon Resources Management (HHRM) is designed with simplicity to avoid the complicated casing design software in the market and provide an in-house tool for quick evaluation of casing scheme options. The development of this MS Excel Based software is motivated by a need to offer a package that accurately predicts relevant well loads, without compromising designs and making it too conservative and expensive or under-conservative and unsafe.

The HHRM Casing Design Application considers all the anticipated loadings on the casing string at the time when the casing is run and throughout the life of the well. The design criteria is such that meet the conflicting requirements of collapse and burst, while ensuring the tensile loading strength of the casing are never exceeded. This application also provides triaxial stress analysis to provide high confidence as regards the ultimate casing scheme to be adopted. This casing design tool has been developed using Visual Basic macros in the Microsoft Excel Environment.

The different components of the Casing Design Tool are presented in this paper. The tool helps the designer make recommendation on combination casing strings from a large casing database or selections based on the client's inventory. The tool has been tested and the results have been found to be consistent with commercial software. The casing design tool is applicable to both vertical and deviated wells.
Paper Title: Well Rejuvenation through ‘Novel Thru-Tubing Sand Screen Insert’ in a Horizontal Completion with Sand Production Challenges
Authors: Emesi John , Ogbunuju Emi , Igbereyivwe Steve , Aronu Godwin , Oyedeji-Olaniyan Olufunsho , Erivona Gloria , Wakama Miebaka
Published: July 2014

Well A (offshore field) was drilled in June 2002 to provide horizontal drainage point on the reservoir. It was completed as a Single String Single (SSS) Producer with 3 ½" tubing string. The sand face was completed with 5 ½" slotted liner (SL) with screen size of 300μm for sand control across 1, 505ft horizontal drain hole since the reservoir is unconsolidated. The interval started production in May 2003 and was closed-in for about a year for pipeline changeout due to pressure integrity before it was shut-in for security concerns. Thereafter the well produced uneventfully until sand production in excess of 10pptb (Pounds per thousand barrel) was observed. Various mitigation efforts were deployed however, all proved abortive. The platform tripped due to the rupture of the well choke body and this was traced to be caused by excessive sand production. The interval was subsequently closed in due to high sand production.

Various options were looked into to determine the best solution that could be used to eliminate the sand production challenges, this ranged from insitu reservoir sand consolidation, horizontal gravel packing, rig re-entry to workover the completion and Thru-Tubing Sand Screen Insert to restore the completion integrity. However after various review sessions, Thru-Tubing Sand Screen Insert was recommended as the best option for the well because it was the most cost effective option, there are good premium screens and in-house expertise exists to aid its deployment. This was followed up with detailed sieve analysis of the produced formation sand and ditch cuttings for proper screen design. Furthermore, well modelling was done to predict the new well potential after the screen insert and was estimated at 2, 250bopd.

In this paper, we present the technique utilized for rejuvenating a horizontal completion in July 2013. 500ft Techdaer-ENFORCER Premium Screens (230micron) was successfully spaced out with 900ft blank tubing and installed inside the top section of the 5 ½" SL and hung off on the production tubing with the Paragon Packer. This was achieved using a Coil Tubing mounted on an offshore Self Elevation Workover Platform (SEWOP) after the well was cleaned up and killed, making it a first in Shell Nigeria. Thereafter, production was restored at low sand cut of < 2pptb, at an average oil rate of 2, 400bopd since August 2013 till date, thereby safe guarding 2.5MMbbls of reserves and 2, 400bopd potential at acceptable sand production. Using a conservative oil price of $85/bbl, the total project cost which was $1.8Mln was recovered in 9days. So far the well has been on production since August 2013 with a cumulative oil production of 0.6MMbbl to date.
Review of Sand Production from Oil Well Completions across Depositional Environments in the Niger Delta
Authors: Onikoyi Abiola S. , Nwabueze Vincent O. , Okoro Felix O. , Ajienka J. A.
Published: July 2014

Several criteria and strategies have been developed to predict sand failures and to select appropriate sand control methods for improved completion designs and to maximise oil production at moderate unit technical cost. The depth criterion, SPADE equation, Rock Mechanic Equations incorporating Brinell Hardness Number and Unconfined Compressive Strength have been used extensively to predict sand production tendencies and to propose completion types. None of these criteria and strategies has explicitly incorporated the depositional environmental factor that defines the origin of these oil-bearing formations. A recent study aimed to correlate depo-belts and depositional environments to actual sand production using historical data of producing wells in the Niger Delta but covered only the Greater Ughelli depo-belt to some depths (SPE-163010). That study indicated a predominance of high sand producers in the channel sands depositional environment of the Greater Ughelli Depobelt. This paper therefore seeks to complete the investigation across all the remaining depo-belts and litho-facies and to share the review outcomes/findings with the goal of establishing correlation between known rock mechanic principles and models used in sand failure prediction and sand control selection as a total system approach, providing wider solutions to sand control challenges in the oil industry.
Gas Market and Contract Management in Integrated Corporate Production Forecasting
Authors: Peter Obidike , Sakiru Adeyanju
Published: July 2014

Gas development projects usually commence from the confirmation of availability of gas markets and contracts before the development planning studies can be initiated. The gas contracts typically feature penalties ("take-or-pay" and related clauses) for not meeting the demand or non acceptance of delivered gas.

With increase in gas demand to meet both export and domestic gas obligations in Nigeria, Companies rely on a robust production forecasting platform to predict and manage the performance of their subsurface assets in a bid to meet those obligations.

This paper explains the strategy in a typical International Oil Company (IOC) in meeting the above objective of achieving an integrated gas market development plan in support of its business planning decisions.
Results of the Second-Monitor 4D Survey in a Nigerian Deepwater Field
Authors: Effiom O. , Lawal K. , Ibianga D. , Njoku C. , Uvieghara O. , Afolabi R.
Published: July 2014

A second monitor 4D seismic was recently acquired over a deepwater field in Nigeria. The acquisition was completed on time and without any Health Safety Security or Environmental incident. This survey used steerable streamers, advanced current prediction techniques, and a dedicated time-lapse data acquisition expert onboard the vessel to guide the sail-lines selection. These improvements contributed to a final 4D dataset with better geometric repeatability than the first seismic monitor acquired four years prior.

Early results of the 4D seismic interpretation of the results from fast-track processing in the different reservoirs reveal two predominant sweep patterns: (a) localized channeling indicative of limited movements within sinuous channels and meander belts; and (b) broad flood-front movement associated with the more lobate, amalgamated systems. This interpretation has provided another level of detail in the understanding of reservoir architecture within the field. Areas of bypassed oil can be identified on 4D seismic and are being used in locating potential additional infill wells. In addition, there has been an improvement in the mapping of the flooded areas of the reservoirs and the seismic-derived flood patterns have provided additional constraints to enhance the quality of the history-matches, resulting in improved static and dynamic subsurface models.
Monitoring the oxygen transfer efficiency of full-scale aeration systems: investigation method and experimental results
Authors: Gori Riccardo , Balducci Alice , Caretti Cecilia , Lubello Claudio
Published: July 2014

This paper reports the results of a series of off-gas tests aimed at monitoring the evolution of the oxygen transfer efficiency in an urban wastewater treatment plant (3,500 population equivalent) located in Tuscany (Italy). The tests were conducted over a 2-year period starting with the testing of the aeration system. It was found that in the absence of membrane-panel cleaning operations, the oxygen transfer efficiency under standard conditions in process water (αSOTE) dropped from 18 to 9.5% in 2 years. This gives rise to a 40% increase in the wastewater treatment plant annual energy costs. The on-site chemical cleaning of the diffusers allowed for an almost total recovery of the transfer efficiency (αSOTE equal to 16%). The use of the off-gas method for monitoring the oxygen transfer efficiency over time is therefore essential for enabling correct planning of the cleaning operations of the diffusers and for cutting the energy consumption and operating costs of the aeration system.
Vertical flow constructed wetlands: kinetics of nutrient and organic matter removal
Authors: Pérez M. M. , Hernández J. M. , Bossens J. , Jiménez T. , Rosa E. , Tack F.
Published: July 2014

The kinetics of organic matter and nutrient removal in a pilot vertical subsurface wetland with red ferralitic soil as substrate were evaluated. The wetland (20 m2) was planted with Cyperus alternifolius. The domestic wastewater that was treated in the wetland had undergone a primary treatment consisting of a septic moat and a buffer tank. From the sixth week of operation, the performance of the wetland stabilized, and a significant reduction in pollutant concentration of the effluent wastewater was obtained. Also a significant increase of dissolved oxygen (5 mg/l) was obtained. The organic matter removal efficiency was greater than 85% and the nutrient removal efficiency was greater than 75% in the vertical subsurface wetland. Nitrogen and biochemical oxygen demand (BOD) removal could be described by a first-order model. The kinetic constants were 3.64 and 3.27 d−1 for BOD and for total nitrogen, respectively. Data on the removal of phosphorus were adapted to a second-order model. The kinetic constant was 0.96 (mg/l)−1 d−1. The results demonstrated the potential of vertical flow constructed wetlands to clean treated domestic wastewater before discharge into the environment.
Deposit membrane fouling: influence of specific cake layer resistance and tangential shear stresses
Authors: Charfi A. , Harmand J. , Ben Amar N. , Grasmick A. , Heran M.
Published: July 2014

Cake fouling is the leading cause of membrane permeability decrease when filtering mixed liquor suspension containing high suspended solid concentrations. A simple model is proposed to simulate the cake resistance evolution with time by considering a macro-scale fouling linked only to the accumulation of particles on the membrane surface. This accumulation appears as the difference between the flux of deposited particles due to the filtration and the flux of particles detached from the membrane surface due to the tangential shear stresses caused by recirculation flow in the sidestream membrane bioreactor (MBR) or gas sparging close to the membrane surface for submerged MBR configuration. Two determining parameters were then highlighted: the specific cake resistance and the ‘shear parameter’. Based on these parameters it is possible to predict model outputs as cake resistance and permeate flux evolution for short-time filtration periods.
Application of three tailing-based composites in treating comprehensive electroplating wastewater
Authors: Liu Hongbo , Zhu Mengling , Gao Saisai
Published: July 2014

Heavy metals and chemical oxygen demand (COD) are major challenging pollutants for most electroplating wastewater treatment plants. A novel composite material, prepared with a mixture of calcium and sodium compounds and tailings, was simply mixed by ratios and used to treat a comprehensive electroplating wastewater with influent COD, total copper (T-Cu), and total nickel (T-Ni) respectively as 690, 4.01, and 20.60 mg/L on average. Operational parameters, i.e. the contact time, pH, mass ratio of calcium and sodium compounds and tailings, were optimized as 30 min, 10.0, and 4:2:1. Removal rates for COD, T-Cu, and T-Ni could reach 71.8, 90.5, and 98.1%, respectively. No significant effect of initial concentrations on removal of T-Cu and T-Ni was observed for the composite material. The adsorption of Cu(II) and Ni(II) on the material fitted Langmuir and Freundlich isotherms respectively. Weight of waste sludge from the calcium/sodium–tailing system after reaction was 10% less than that from the calcium–tailing system. The tailing-based composite is cost-effective in combating comprehensive electroplating pollution, which shows a possibility of applying the tailings in treating electroplating wastewater.
Analysis of nitrogenous and algal oxygen demand in effluent from a system of aerated lagoons followed by polishing pond
Authors: Khorsandi Hassan , Alizadeh Rahimeh , Tosinejad Horiyeh , Porghaffar Hadi
Published: July 2014

In this descriptive-analytical study, nitrogenous and algal oxygen demand were assessed for effluent from a system of facultative partially mixed lagoons followed by the polishing pond using 120 grab samples over 1 year. Filtered and non-filtered samples of polishing pond effluent were tested in the presence and absence of a nitrification inhibitor. Effective factors, including 5-day biochemical and chemical oxygen demand (BOD and COD), total suspended solids (TSS), dissolved oxygen, chlorophyll A, and temperature, were measured using standard methods for water and wastewater tests. The results were analyzed using repeated measures analysis of variance with SPSS version 16. Findings show that the annual mean of the total 5-day BOD in the effluent from the polishing pond consisted of 44.92% as the algal carbonaceous biochemical oxygen demand (CBOD), 43.61% as the nitrogenous biochemical oxygen demand (NBOD), and 11.47% as the soluble CBOD. According to this study, the annual mean ratios of algal COD and 5-day algal CBOD to TSS were 0.8 and 0.37, respectively. As the results demonstrate, undertaking quality evaluation of the final effluent from the lagoons without considering nitrogenous and algal oxygen demand would undermine effluent quality assessment and interpretation of the performance of the wastewater treatment plant.
User-awareness and adaptation in conversational agents
Authors: Delic Vlado , Gnjatovic Milan , Jakovljevic Niksa , Popovic Branislav , Jokic Ivan , Bojanic Milana
Published: July 2014

This paper considers the research question of developing user-aware and
adaptive conversational agents. The conversational agent is a system which is
user-aware to the extent that it recognizes the user identity and his/her
emotional states that are relevant in a given interaction domain. The
conversational agent is user-adaptive to the extent that it dynamically
adapts its dialogue behavior according to the user and his/her emotional
state. The paper summarizes some aspects of our previous work and presents
work-in-progress in the field of speech-based human-machine interaction. It
focuses particularly on the development of speech recognition modules in
cooperation with both modules for emotion recognition and speaker
recognition, as well as the dialogue management module. Finally, it proposes
an architecture of a conversational agent that integrates those modules and
improves each of them based on some kind of synergies among themselves.
Implementation of artificial neural networks based AI concepts to the smart grid
Authors: Dimitrijevic Marko , Andrejevic-Stosovic Miona , Milojkovic Jelena , Litovski Vanco
Published: July 2014

ICT and energy are two economic domains that became among the most
influential to the growth of modern society. These, in the same time, due to
exploitation of natural resources and producing unwanted effects to the
environment, represent a kind of menace to the eco system and the human
future. Implementation of measures to mitigate these unwanted effects
established a new paradigm of production and distribution of electrical
energy named smart grid. It relies on many novelties that improve the
production, distribution and consumption of electricity among which one of
the most important is the ICT. Among the ICT concepts implemented in modern
smart grid one recognizes the artificial intelligence and, specifically the
artificial neural network. Here, after reviewing the subject and setting the
case, we are reporting some of our newest results aiming at broadening the
set of tools being offered by ICT to the smart grid. We will describe our
result in prediction of electricity demand and characterization of new
threats to the security of the ICT that may use the grid as a carrier of the
attack. We will use artificial neural networks (ANNs) as a tool in both
subjects.
Wireless sensor node with low-power sensing
Authors: Nikolic Goran , Stojcev Mile , Stamenkovic Zoran , Panic Goran , Petrovic Branislav
Published: July 2014

Wireless sensor network consists of a large number of simple sensor nodes
that collect information from external environment with sensors, then process
the information, and communicate with other neighboring nodes in the network.
Usually, sensor nodes operate with exhaustible batteries unattended. Since
manual replacement or recharging of the batteries is not an easy, desirable
or always possible task, the power consumption becomes a very important issue
in the development of these networks. The total power consumption of a node
is a result of all steps of the operation: sensing, data processing and radio
transmission. In most published papers in literature it is assumed that the
sensing subsystem consumes significantly less energy than a radio block.
However, this assumption does not apply in numerous applications, especially
in the case when power consumption of the sensing activity is comparably
bigger than that of a radio. In that context, in this work we focus on the
impact of the sensing hardware on the total power consumption of a sensor
node. Firstly, we describe the structure of the sensor node architecture,
identify its key energy consumption sources, and introduce an energy model
for the sensing subsystem as a building block of a node. Secondly, with the
aim to reduce energy consumption we investigate joint effectiveness of two
common power-saving techniques in a specific sensor node: duty-cycling and
power-gating. Duty-cycling is effective at the system level. It is used for
switching a node between active and sleep mode (with the duty-cycle factor of
1%, the reduction of in dynamic energy consumption is achieved). Power-gating
is used at the circuit level with the goal to decrease the power loss due to
the leakage current (in our design, the reduction of dynamic and static
energy consumption of off-chip sensor elements as constituents of sensing
hardware within a node of is achieved). Compared to a sensor node
architecture in which both energy saving techniques are omitted, the
conducted MATLsimulation results suggest that in total, thanks to
involving duty-cycling and power-gating techniques, a three order of
magnitude reduction for sensing activities in energy consumption can be
achieved.
Load modelling at low voltage using continuous measurements
Authors: Korunovic Lidija , Rasic Milica , Floranovic Nenad , Aleksic Vladica
Published: July 2014

The paper presents the results of load modelling at low voltage level of
transformer station (TS) 10/0.4 kV/kV supplying predominantly the residential
load. The necessary data is obtained from a recording device and measuring
information system for continuous measurements permanently installed in the
concerned distribution network. The identified parameters of static
exponential load model are classified according to day periods and days of
the week, and statistically analysed in order to obtain reliable parameter
estimates. These are compared with literature data for the same residential
load class. Possibilities for further application of the described load
modelling procedure are listed.
Vocabulary growth at tertiary level: How much progress can Serbian EFL learners make in a year?
Authors: Danilovic Jelena , Grujic Tatjana
Published: July 2014

The size of L2 learners? vocabulary, both receptive and productive,
represents a vital concept in the field of L2 acquisition, given that it
determines the degree of success in communication. The larger the vocabulary
size of a learner is, the better his/her understanding and ease of
communication in the target language. For this reason, a body of research
focusing on the developmental process of lexical acquisition in L2 learners
of various proficiency levels (beginner, intermediate, advanced) in different
teaching contexts is nowadays steadily expanding. A recent study aimed at
investigating the relationship between lexical reception and production in
Serbian L1 English L2 learners, English language majors, has indicated that
production seriously lags behind reception. Therefore, the aim of this paper
was to explore the growth in receptive and productive vocabulary size of
B2-level (CEFR) English L2 learners, first year English majors, over a period
of a single academic year. The data obtained reveal that the rich L2 input
provided in Integrated skills classes, combined with other compulsory and
elective courses predominantly held in English, has resulted in the learners?
productive lexical knowledge developing faster than their receptive lexical
knowledge. This outcome consequently affected the relationship between the
learners? receptive and productive vocabulary size - the gap between the two
narrowed.
Islet-1 Is Essential for Pancreatic β-Cell Function
Authors: Ediger Benjamin N. , Du Aiping , Liu Jingxuan , Hunter Chad S. , Walp Erik R. , Schug Jonathan , Kaestner Klaus H. , Stein Roland , Stoffers Doris A. , May Catherine L.
Published: July 2014

Islet-1 (Isl-1) is essential for the survival and ensuing differentiation of pancreatic endocrine progenitors. Isl-1 remains expressed in all adult pancreatic endocrine lineages; however, its specific function in the postnatal pancreas is unclear. Here we determine whether Isl-1 plays a distinct role in the postnatal β-cell by performing physiological and morphometric analyses of a tamoxifen-inducible, β-cell–specific Isl-1 loss-of-function mouse: Isl-1L/L; Pdx1-CreERTm. Ablating Isl-1 in postnatal β-cells reduced glucose tolerance without significantly reducing β-cell mass or increasing β-cell apoptosis. Rather, islets from Isl-1L/L; Pdx1-CreERTm mice showed impaired insulin secretion. To identify direct targets of Isl-1, we integrated high-throughput gene expression and Isl-1 chromatin occupancy using islets from Isl-1L/L; Pdx1-CreERTm mice and βTC3 insulinoma cells, respectively. Ablating Isl-1 significantly affected the β-cell transcriptome, including known targets Insulin and MafA as well as novel targets Pdx1 and Slc2a2. Using chromatin immunoprecipitation sequencing and luciferase reporter assays, we found that Isl-1 directly occupies functional regulatory elements of Pdx1 and Slc2a2. Thus Isl-1 is essential for postnatal β-cell function, directly regulates Pdx1 and Slc2a2, and has a mature β-cell cistrome distinct from that of pancreatic endocrine progenitors.
Central Insulin Administration Improves Whole-Body Insulin Sensitivity via Hypothalamus and Parasympathetic Outputs in Men
Authors: Heni Martin , Wagner Robert , Kullmann Stephanie , Veit Ralf , Mat Husin Haliza , Linder Katarzyna , Benkendorff Charlotte , Peter Andreas , Stefan Norbert , Häring Hans-Ulrich , Preissl Hubert , Fritsche Andreas
Published: July 2014

Animal studies suggest that insulin action in the brain is involved in the regulation of peripheral insulin sensitivity. Whether this holds true in humans is unknown. Using intranasal application of insulin to the human brain, we studied the impacts of brain insulin action on whole-body insulin sensitivity and the mechanisms involved in this process. Insulin sensitivity was assessed by hyperinsulinemic-euglycemic glucose clamp before and after intranasal application of insulin and placebo in randomized order in lean and obese men. After insulin spray application in lean subjects, a higher glucose infusion rate was necessary to maintain euglycemia compared with placebo. Accordingly, clamp-derived insulin sensitivity index improved after insulin spray. In obese subjects, this insulin-sensitizing effect could not be detected. Change in the high-frequency band of heart rate variability, an estimate of parasympathetic output, correlated positively with change in whole-body insulin sensitivity after intranasal insulin. Improvement in whole-body insulin sensitivity correlated with the change in hypothalamic activity as assessed by functional magnetic resonance imaging. Intranasal insulin improves peripheral insulin sensitivity in lean but not in obese men. Furthermore, brain-derived peripheral insulin sensitization is associated with hypothalamic activity and parasympathetic outputs. Thus, the findings provide novel insights into the regulation of insulin sensitivity and the pathogenesis of insulin resistance in humans.
Use of trazodone to facilitate postsurgical confinement in dogs
Authors: Gruen Margaret E. , Roe Simon C. , Griffith Emily , Hamilton Alexandra , Sherman Barbara L.
Published: July 2014

Objective—To investigate the safety and efficacy of oral administration of the serotonin antagonist and reuptake inhibitor trazodone hydrochloride to facilitate confinement and calming after orthopedic surgery in dogs.

Design—Prospective open-label clinical trial.

Animals—36 client-owned dogs that underwent orthopedic surgery.

Procedures—Starting the day after surgery, dogs were administered trazodone (approx 3.5 mg/kg [1.6 mg/lb], PO, q 12 h) with tramadol (4 to 6 mg/kg [1.8 to 2.7 mg/lb], PO, q 8 to 12 h) for pain management. After 3 days, administration of tramadol was discontinued, and the trazodone dosage was increased (approx 7 mg/kg [3.2 mg/lb], PO, q 12 h) and maintained for at least 4 weeks. If needed, trazodone dosage was increased (7 to 10 mg/kg [3.2 to 4.5 mg/lb], PO, q 8 h). Owners completed electronic surveys rating their dogs’ confinement tolerance, calmness or hyperactivity level, and responses to specific provocative situations prior to surgery and 1, 2, 3, and 4 weeks after surgery and at the postsurgery evaluation (at 8 to 12 weeks).

Results—Most (32/36 [89%]) of owners reported that their dogs, when given trazodone during the 8 to 12 weeks following orthopedic surgery, improved moderately or extremely with regard to confinement tolerance and calmness. Trazodone was well tolerated, even in combination with NSAIDs, antimicrobials, and other medications; no dogs were withdrawn from the study because of adverse reactions. Owner-reported median onset of action of trazodone was 31 to 45 minutes, and median duration of action was ≥ 4 hours.

Conclusions and Clinical Relevance—Results suggested that oral administration of trazodone was safe and efficacious and may be used to facilitate confinement and enhance behavioral calmness of dogs during the critical recovery period following orthopedic surgery.
Sewing needle foreign body ingestion in dogs and cats: 65 cases (2000–2012)
Authors: Pratt Chap L. , Reineke Erica L. , Drobatz Kenneth J.
Published: July 2014

Objective—To characterize clinical signs, diagnostic test results, foreign body location, treatment, and outcome for dogs and cats with sewing needle foreign bodies.

Design—Retrospective case series.

Animals—65 dogs and cats with sewing needle foreign bodies.

Procedures—Medical records of 27 dogs and 38 cats examined because of sewing needle foreign bodies from January 2000 to February 2012 were reviewed for signalment, medical history, physical examination findings, diagnostic test results, interval from witnessed exposure and radiographic imaging to definitive treatment, definitive treatment, sewing needle location, complications, and outcome.

Results—7 (10.8%) animals had sewing needles in extragastrointestinal locations that were not causing clinical signs. The remaining 58 (89.2%) animals had known sewing needle exposure or acute clinical signs associated with ingestion. The esophageal and gastric regions were the most common location for a sewing needle (10/21 [47.6%] dogs; 19/37 [51.4%] cats), followed by the oropharynx (7/21 [33.3%] dogs; 11/37 [29.7%] cats) and small and large intestines (4/21 [19.0%] dogs; 7/37 [18.9%] cats). Gastrointestinal perforation was detected in 10 of 58 (17.2%) animals (5/21 [23.8%] dogs; 5/37 [13.5%] cats). Sewing needles in the esophagus and stomach were successfully removed endoscopically in 8 of 9 dogs and 18 of 19 cats. Survival rate was 98.1% (51/52) for animals receiving definitive treatment.

Conclusions and Clinical Relevance—Endoscopic removal of ingested sewing needles was highly successful and should be recommended to prevent gastrointestinal tract perforation and associated morbidity. Prognosis for dogs and cats receiving definitive treatment for sewing needle foreign body ingestion was excellent.
Frequency of Corynebacterium pseudotuberculosis infection in horses across the United States during a 10-year period
Authors: Kilcoyne Isabelle , Spier Sharon J. , Carter Craig N. , Smith Jacqueline L. , Swinford Amy K. , Cohen Noah D.
Published: July 2014

Objective—To quantify the number of horses with Corynebacterium pseudotuberculosis infection identified in the United States from January 2003 through December 2012.

Design—Cross-sectional study.

Sample—State veterinary diagnostic laboratory records of 2,237 C pseudotuberculosis culture-positive samples from horses.

Procedures—44 state veterinary diagnostic laboratories throughout the United States were invited by mail to participate in the study. Data requested included the number of C pseudotuberculosis culture-positive samples from horses identified per year, geographic location from which the C pseudotuberculosis culture-positive sample was submitted, month and year of sample submission, breed and age of horses, and category of clinical manifestation (ie, internal infection, external infection, or ulcerative lymphangitis).

Results—Of the 44 invited laboratories, 15 agreed to participate and provided data on affected horses from 23 states. The proportion of C pseudotuberculosis culture-positive samples submitted during 2011 through 2012 (1,213/2,237 [54%]) was significantly greater than that for the period from 2003 through 2010 (1,024/2,237 [46%]). Corynebacterium pseudotuberculosis was recovered from horses in states where the disease has not been previously recognized as endemic. Affected horses were identified year-round. The greatest proportion of C pseudotuberculosis culture-positive samples was identified during November, December, and January (789/2,237 [35%]). No significant association between the clinical form of disease and age or breed of horse was observed.

Conclusions and Clinical Relevance—The occurrence of C pseudotuberculosis infection in horses increased during the 10-year period, and affected horses were identified throughout the United States. Further studies to determine changes in annual incidence and to identify potential changing climatic conditions or vector populations associated with disease transmission are warranted to help control the occurrence and spread of C pseudotuberculosis infection in horses.
Impact of Feed Rations on Growth, Selected Body Parameters and Maturation of Vendace, Coregonus Albula L., Reared in RAS
Authors: Szczepkowska Bożena , Szczepkowski Mirosław , Piotrowska Iwona
Published: July 2014

Vendace, Coregonus albula L., was reared to commercial size in a recirculating system. Three different feed rations were applied during the ten-month-long experiment. The feed rations impacted fish growth rates, and fish in the different groups achieved body weights of 26.6 g to 57.5 g. The final survival in all groups was similar from 44.3% among the fish fed the smallest feed ration to 53.2% in the group receiving the largest feed ration. No differences were noted in the share of viscera, peritoneal fat, or in the hepatosomatic indexes, but there were differences in the gonadosomatic indexes. After thermal stimulation, only males achieved sexual maturity. The number of mature fish was similar in all groups and ranged from 17.8 to 21.3% of all fish. The results of the present study indicated that vendace can achieve commercial size in an intensive rearing period of ten months in RAS.
Leaf Rolling Reduces Photosynthetic Loss in Maize Under Severe Drought
Authors: Saglam Aykut , Kadioglu Asim , Demiralay Mehmet , Terzi Rabiye
Published: July 2014

Effects of leaf rolling (LR) on maize photosynthesis under severe drought stress were studied in two cultivars with opposite drought responses, Batem 56-55 (drought tolerant) and Batem 51-52 (drought sensitive). Drought stress and artificial prevention of leaf rolling (PLR) were applied at grain filling stage for 30 days. LR in Batem 56-55 occurred later than in Batem 51-52. Leaf water potential (Ψleaf) did not change in Batem 56-55 but decreased in Batem 51-52 at LR. Maximum quantum yield of photosystem II (Fv/Fm), effective quantum yield of photosystem II (ΦPSII) and electron transport rate (ETR) of the cultivars decreased during LR more significantly in Batem 56-55 in comparison to Batem 51-52. The same was observed for the decrease in net photosynthetic rate (Pn), stomatal conductance (gs), transpiration (E) and intracellular level of CO2(C). Rubis-co activity and content were reduced at LR, but were less affected in Batem 56-55 than in Batem 51-52. Ear and kernel weights also decreased at LR. All parameters at PLR were more reduced than those of LR. These results implied that LR was an important and necessary mechanism protecting photosynthesis and reducing yield loss under drought stress by maintaining the leaf hydration, preventing loss of the photosynthetic pigments, sustaining the activity of PSU, keeping the stornata open, and conserving the activity of Rubisco.
Codes on Key Errors
Authors: Das P. K.
Published: July 2014

Coding theory has started with the intention of detection and correction of errors which have occurred during communication. Different types of errors are produced by different types of communication channels and accordingly codes are developed to deal with them. In 2013 Sharma and Gaur introduced a new kind of an error which will be termed “key error”. This paper obtains the lower and upper bounds on the number of parity-check digits required for linear codes capable for detecting such errors. Illustration of such a code is provided. Codes capable of simultaneous detection and correction of such errors have also been considered.
Colour Restoration of Image Obtained from CCD Sensor Directly
Authors: Luo Jun , Chen Ying
Published: July 2014

The original image data obtained from Charge-coupled Device (CCD) can be called original data, which is lack of color information. In order to restore the color of original image, firstly, we design a Bayer color filter array, and then we use bilinear interpolation algorithm and smooth hue transition interpolation algorithm to restore the color of original image. However, the hues of adjacent pixels change abruptly by the bilinear interpolation, therefore, we use smooth hue transition interpolation to enhance the edge of original image, and finally we identify the ultimate performance of these interpolation algorithms.
Benchmark of Different Gradient Descents in OCR
Authors: Rafsanjani Marjan Kuchaki , Pourshaban Masoud
Published: July 2014

In this paper we implement six different learning algorithms in Optical Character Recognition (OCR) problem and achieve the criteria of end-time, number of iterations, train-set performance, test-set performance, validate-set performance and overall performance of these methods and compare them. Finally, we show the advantages and disadvantages of each method.
Telephone Speech Endpoint Detection using Mean-Delta Feature
Authors: Ouzounov Atanas
Published: July 2014

In the study the efficiency of three features for trajectory-based endpoint detection is experimentally evaluated in the fixed-text Dynamic Time Warping (DTW) - a based speaker verification task with short phrases of telephone speech. The employed features are Modified Teager Energy (MTE), Energy-Entropy (EE) feature and Mean-Delta (MD) feature. The utterance boundaries in the endpoint detector are provided by means of state automaton and a set of thresholds based only on trajectory characteristics. The training and testing have been done with noisy telephone speech (short phrases in Bulgarian language with length of about 2 s) selected from BG-SRDat corpus. The results of the experiments have shown that the MD feature demonstrates the best performance in the endpoint detection tests in terms of the verification rate.
Anchoring Tri(8-Quinolinolato)Iron Onto Sba-15 for Partial Oxidation of Benzyl Alcohol Using Water as the Solvent
Authors: Yang Xiaoyuan , Liu Jing , Kan Qiubin , Guan Jingqi
Published: July 2014

Tri(8-quinolinolato)iron complex immobilized onto SBA-15 catalyst has been synthesized through a stepwise procedure. The characterization results indicated that the BET surface area, total pore volume and average pore width decrease after stepwise modification of SBA-15, while the structure keeps intact. Catalytic tests showed that FeQ3-SBA-15 catalyzes the oxidation reaction well with 34.8% conversion of benzyl alcohol and 74.7% selectivity to benzaldehyde when water is used as the solvent after 1 h reaction. In addition, homogeneous catalyst tri(8-quinolinolato)iron exhibits very bad catalytic behavior using water as the solvent.