bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of an Economical Integrity Management Strategy - An Integrated Approach to Optimise and Prioritise Integrity Related Well Intervention Operations
Authors: Taghiyev Kanan , Wilkie Peter , Harper Christopher S. , Kuswiranto Agung
Published: April 2016

A well intervention can be a significant cost during a well's lifetime because it entails lost production, caliper surveys, rigging up expensive workover equipment and possesses HSE risks. These high costs impact the operations of mature fields, especially during market downturns. To address the cost effectiveness of well workover activities, an integrated strategy was developed utilising corrosion, erosion and tubing stress analyses. The approach aims to defer unnecessary well interventions and efficiently control budgets using prioritisation of integrity-related well operations.

The proposed holistic workflow for integrity management is based upon the application of well modelling, corrosion, erosion and tubing stress analyses. These elements utilise industry-standard equations and principles to evaluate the potential for integrity loss. The corrosion analyses are based upon the corrected de Waard Milliams correlation, measured corrosion rates and the application of equations of state and thermodynamics to calculate hydrogen sulphide partitioning if sour conditions are prevalent.

Well performance modelling is linked with corrosion analyses where factors such as production rate forecasts, flow velocities, water alkalinity, tubing profile and PVT data are considered. Erosion is an important factor that impacts metallurgy longevity. To calculate erosion rates along production tubing, erosion analyses are supported and correlated with empirical data specific to individual pipe geometry and the metal behavior when contacted by particles in specific flow regimes. Stress analyses calculates various tubing safety factors (burst, collapse, axial and triaxial) to assess the time, mechanism and risk of tubing failure using production rate forecasts, wall thickness and metal loss results obtained from corrosion and erosion analyses.

Because of the complexity of corrosion, corrosion prediction models can significantly over-estimate corrosion rates by several orders of magnitude. Tuning prediction models to caliper data accounts for field-specific factors, e.g. hydrocarbon properties and scale deposition, significantly improve the accuracy of subsequent predictions and increase confidence in well-integrity-review results.

This workflow enables operators to control and balance capital (CAPEX) and operational expenditure (OPEX) related to completions and maintenance by enabling them to more accurately predict failures, plan work-over operations and assess the most cost-effective strategy.
Corrosion Study by Using Realistic Brine Composition Under Strictly Anoxic Conditions at xHPHT
Authors: Yan Chao , Guraieb Paula , Tomson Ross C.
Published: April 2016

Published corrosion studies have demonstrated the formation of a passive layer and assessed corrosion rate in a NaCl matrix fluid. However, a critical issue for corrosion laboratory tests is to simulate realistic downhole and reservoir brine composition and conditions, which includes a complex matrix of Na+, K+, Mg2+, Ca2+, Sr2+, Ba2+, Fe2+, HCO3–, CO2(aq), and others. Just as crucial, dissolved oxygen concentration should be controlled at reservoir conditions which are strictly anoxic (<< 1 ppb dissolved O2), especially for projects dealing with ferrous iron. Strictly anoxic conditions are crucial for evaluating efficiency and degradation of corrosion inhibitors because dissolved oxygen may interfere and even react with corrosion inhibitors under production temperatures and pressures.

Flow-through corrosion tests were performed for 3 weeks at 200 °C and 1,380 bar. The feed solutions were prepared to represent realistic field brines with complex mixtures of cations and anions, instead of using only NaCl, as is commonly done. All solutions were strictly anoxic (<< 1 ppb dissolved O2). Ferrous iron is from the dissolution of carbon steel 1010 due to corrosion. Mineral deposits on the inner surface of test tubings were collected for XRD and SEM analyses.

A single phase of ankerite (CaMg0.27Fe0.73(CO3)2) was observed instead of siderite (FeCO3), calcite (CaCO3), or magnetite (Fe3O4), which are commonly reported as corrosion products at temperatures above 150 °C. Strictly anoxic conditions allow iron to exist in its ferrous form causing it to incorporate into the ankerite structure, as would be seen in the reservoir and production stream. SEM images and XRD composition of the corrosion products showed that the inner surface of test tubing was uniformly covered by ankerite.

These results demonstrate that more complicated corrosion products can form under simulated downhole environment by using realistic brine compositions under strictly anoxic conditions. The surface properties, solubility, and density of this passive layer could be very different from siderite (FeCO3) and magnetite (Fe3O4), which could cause different protection properties. As a result, corrosion rates may be different than previously reported under extreme conditions and should be studied further.
Assessment of Corrosion Rates Under High Shear Conditions - Developments in Laboratory Testing
Authors: Thomson Hunter , Bowering Deborah , Simpson Caroline M. , Ray John , Frigo Dario M. , Graham Gordon M.
Published: April 2016

The use of inflow-control valves (ICVs) and inflow-control devices (ICDs) to improve production rates in horizontal wells has become increasingly common in recent years. These devices have small apertures resulting in high, local high flow rates which results in regimes of very high shear and turbulence, potentially resulting in materials failure due to accelerated corrosion rates, erosion and potentially erosion-corrosion.

To meet the challenge of testing accelerated corrosion rates, various laboratory methods have been developed to study the effects of increasing shear on corrosion. Common test methods such as rotating-cylinder electrode (RCE) tests can provide useful data at moderate shear stresses (up to 100 Pa) and ambient pressures, while rotating-cage autoclave tests (RCA) and rotating-cylinder electrochemical autoclave (RCEA) tests allow moderate shear tests to be conducted at elevated temperatures and pressures. However, achieving the very high wall shear stresses seen with certain oilfield jewellery, such as ICVs and ICDs, is significantly more challenging.

In contrast, jet impingement (JI) methods have enabled materials testing at up to 10,000 Pa, and by coupling these with the ability to conduct these tests under increasingly higher pressures and temperatures, very-high-shear systems can be tested under conditions closely matched to those in the field. The approaches developed in our laboratories, which use both weight loss and electrochemical corrosion measurements, have also proved to be robust even in extremely corrosive environments, such as in the presence of stimulation acids (both uninhibited and inhibited) and over extended exposure times (> 7 days).

These jet-impingement test methods have enabled enhanced understanding of the susceptibility of various materials to corrosion and erosion under extremely high shear conditions, and how effectively (or not) film-forming corrosion inhibitors perform. The application of these advanced laboratory techniques is currently playing a vital role in evaluating suitable methods for preventing corrosion under very challenging conditions before deployment in the field.
Detecting and Removing Outliers in Production Data to Enhance Production Forecasting
Authors: Chaudhary Nitinkumar L. , Lee W. John
Published: April 2016

The objective of the study summarized in this paper was to establish a robust method to detect outliers in rate and pressure data used for decline analysis and forecasting, pressure and rate transient analysis, and similar workflows. Presence of outliers contributes significantly to the uncertainty and non-uniqueness associated with the rate/pressure transient analysis workflow.

In time-series data usually encountered in rate/pressure transient analysis workflows, we observed that the neighboring data points of an inlying data point will be closer to the point as compared to closeness of an outlier data point. The outlier detection method we developed exploits this observation. It relies on the concept of local density around a data point, and locality is quantified by a function of distance of the data point from its k-nearest neighbors. This concept further maps into a local outlier factor, which signifies the quantitative extent of a data point being an outlier. Outliers will have a higher value of local outlier factor than will inlying data points. A threshold value of local outlier factor is used to label the data points as outliers, and this threshold is set using the histogram of local outlier factor values.

Most commonly used outlier detection methods in the industry assume that rate/pressure data follow a known model (e.g., a Gaussian probability distribution model), but outliers deviate strongly from this model. In the usual parametric-model-based approach, an a priori assumption of the correct model needs to be verified, which can limit the validity of the approach. The newly proposed outlier detection method, being non-parametric, is more robust as it is independent of the assumption that data follows a known model.

We present a synthetic case study demonstrating the importance of outlier detection and outlining the limitations of currently used outlier detection methods. We then validate our method through synthetic examples generated using numerical models of multi-stage hydraulically fractured wells in unconventional reservoirs. Upon validation we demonstrate application of our method using field examples from four major shale plays.
The Practice of Decline Curve Analysis
Authors: Purvis D. C.
Published: April 2016

Though it is the oldest and most common of the six engineering techniques for the determination of reserves, both the theory and practice of decline curves continue to suffer from widespread misunderstanding and lackluster implementation. Decline curve analysis is not a curve-fitting exercise, and it should not be limited to a single rate-time graph of each well in isolation, much less just any rate-time graph created by the sloppy defaults of most graphing programs.

Decline curve analysis is an exercise in seeing, understanding and predicting the reservoir and operational dynamics. A practitioner should be adept at creating graphs from which she can identify reservoir dynamics, trace trends as precisely as possible and thus anticipate likely future behavior. Graphs should show only relevant data and show it clearly, without distraction. Multiple graphs examined in parallel often lead to better insights, though the graphs and their contents may vary among situations. Besides drawing on general experience, an evaluator often needs to examine the nearest and best analog production trends to make good forecasts. To do all this, the evaluator needs to be able to discriminate operational changes and to understand the uncertainty of the production data itself.
Mexico's Initiatives to Increase Oil Production and its Effect on North America Oil Production Outlook
Authors: Suarez Ricardo G. , Vazquez Alfredo Valdes , Roman Francisco J. , Rubio Francisco Pams
Published: April 2016

Mexico's oil production has been declining for the last decade. Therefore, the country has established strategies to increase oil production including the acquisition of new technology to produce unconventional reservoirs as well as the implementation of new regulations to enhance recovery rates from mature fields and develop the shallow-water and deepwater areas.

This paper presents a detailed analysis of Mexico's new hydrocarbons legislation with special focus on the contracting and bidding processes. This research also considers available data to identify the main technical challenges associated with the contractual areas which ultimately may be crucial in increasing oil production. Prospective production from main Mexican reservoirs was evaluated using a probabilistic method based on decline curve analysis (DCA) to forecast Mexico's oil production and its effect on North America oil production outlook.

The results of the technical evaluation of the contractual areas along with the analysis of the new policies indicate optimistic scenarios for the development of projects and a potential increase in oil production. These projects will foster offset decline of oil production by attracting experienced companies capable of facing current technical challenges and increasing upstream investment. Furthermore, areas of opportunity in the new regulations were identified to make the project conditions more attractive for companies and government. This study is built upon the exhaustive analysis of the new legislation and characteristics of the contractual areas in the context of the current internal and external factors to forecast Mexico's oil production scenario.
The Effect of Costs and Efficiencies on the Economic Viability and Resiliency of Production from Unconventional Reservoirs
Authors: Ozkan S.
Published: April 2016

Since mid-2014, crude oil prices have declined significantly. Many producing countries have large portions of their resource base uneconomic at the time of writing. However, after the fundamental imbalance between supply and demand is fixed, high storage levels are worked off, and demand for petroleum products continues to grow, the prices for crude oil will need to rise to incentivize production growth around the world. The United States has unlocked, through the shale revolution, a very economic resource base. Although current prices are not sustainable and increased prices will have to materialize to grow production volumes around the world, the required price does not need to be anywhere near the $100/Bbl levels previously observed. This is due to the amount of production that the United States can bring to the market at price levels below that. This paper provides insight into the amount of production that could be brought online in the United States at different crude oil price levels. It also studies the effects of cost efficiencies and natural gas prices on the volumes of crude oil that can be produced economically at different prices. The results show that the United States can grow production at a sufficient rate to track with demand growth at $65/Bbl WTI.
Unconventional Plays, Various Lithologies - Constant Stress Gradients
Authors: Parotidis Miltiadis , Hummel Nicolas , Graham Jordan , Wheeler Josephine , Pritchard Tim
Published: April 2016

Three onshore basins (called henceforth A, B, and C) in eastern Australia are discussed in this paper with the focus on geomechanics. Basin A is a coal seam gas play with a few thousand wells already drilled, and reservoir layers in the depth range of 300 to 1000 m, inter-bedded with impermeable clastics. Stress determination has been a key challenge as initial minifrac interpretations showed significant scatter in stress and pore pressure results. But with more consistent processing and interpretation constant effective stress ratios could be defined over large areas and depth sections. This helped also in interpreting microseismic data related to hydraulic fracturing – essential for economic production in areas of lower coal permeability - as reactivation of existing natural fractures seems to take place during injection. Basins B and C with tight formations as reservoir targets, in depths of about 4000 to 4600 m show overpressures that are difficult to directly measure and could only be constrained to lower values than mini frac test interpretations, after iteratively calibrating the geomechanical model and considering drilling data. This allowed a better understanding of thermal effects on progressing shear failure in openhole sections, due to increasing drilling mud fluids temperature with time; an effect that has to be considered in defining safe mud windows for drilling and operations phases. Although gradually a better understanding has been achieved, above unconventional fields still pose challenges, and current results will have to be considered as work in progress and not final. The key outcome of the geomechanics studies to date is: that a strike-slip stress regime applies, regionally and vertically; several depth intervals show constant effective stress ratios for both horizontal stresses, with some changes depending on location, and probably due to the structural differences.
PCR-based Approaches for the Detection of Clinical Methicillin-resistant Staphylococcus aureus
Authors: Liu Ying , Zhang Jiang , Ji Yinduo
Published: April 2016

Staphylococcus aureusis an important pathogen that can cause a variety of infections, including superficial and systematic infections, in humans and animals. The persistent emergence of multidrug resistantS. aureus, particularly methicillin-resistantS. aureus, has caused dramatically economic burden and concerns in the public health due to limited options of treatment of MRSA infections. In order to make a correct choice of treatment for physicians and understand the prevalence of MRSA, it is extremely critical to precisely and timely diagnose the pathogen that induces a specific infection of patients and to reveal the antibiotic resistant profile of the pathogen. In this review, we outlined different PCR-based approaches that have been successfully utilized for the rapid detection ofS. aureus, including MRSA and MSSA, directly from various clinical specimens. The sensitivity and specificity of detections were pointed out. Both advantages and disadvantages of listed approaches were discussed. Importantly, an alternative approach is necessary to further confirm the detection results from the molecular diagnostic assays.
Utilization of Drinking Water Treatment Slurry to Produce Aluminum Sulfate Coagulant
Authors: Fouad Mahmoud M. , Razek Taha M. A. , Elgendy Ahmed S.
Published: April 2016

In Egypt, water treatment consumes about 365 000 tons of aluminum sulfate and produces more than 100 million tons of sludge per year. The common disposal system of sludge in Egypt is to discharge it into natural waterways. Toxicity of aluminum, environmental regulations and costs of chemicals used in water treatment and sludge treatment processes led to an evaluation of coagulant recovery and subsequent reuse. The present work aimed at aluminum recovery from sludge of El‐Shiekh Zayd water treatment plant (WTP) to produce aluminum sulfate coagulant. Sludge was characterized and the effect of five variables was tested and the process efficiency was evaluated at different operating conditions. Maximum recovery is 94.2% at acid concentration 1.5 N, sludge weight 5 g, mixing speed 60 rpm, temperature 60 °C and leaching time 40 min. Then optimum conditions were applied to get maximum recovery for aluminum sulfate and compared to commercial coagulant on raw water of El‐Shiekh Zayd (WTP).
Effect of Food Waste Co‐Digestion on Digestion, Dewatering, and Cake Quality
Authors: Higgins Matthew , Rajagopalan Ganesh , Miller Andre , Brown Jeffrey , Beightol Steven
Published: April 2016

The objective of this study was to evaluate the effect of food waste addition on anaerobic digestion performance as well as downstream parameters including dewatering, cake quality, and filtrate quality. Laboratory‐scale digesters were fed processed food waste at rates of 25%, 45%, and 65% increased chemical oxygen demand (COD) loading rates compared to a control fed only primary and secondary solids. The specific methane yield increased from 370 L CH4/kg VSadded for the control to 410, 440, and 470 L CH4/kg VSadded for the 25, 45, and 65% food waste addition, respectively. The cake solids after dewatering were all higher for the food waste digesters compared to the control, with the highest cake solids being measured for the 45% food‐waste loading. Compared to the control digester, the biosolids odorant concentration increased for the lowest dose of food waste. Odorant concentrations were below detection for the highest food waste loading.
Effects of natural broadleaved regeneration vs conifer restoration on the herb layer and microclimate
Authors: Vukov Dragana , Galic Zoran , Rucando Marko , Ilic Milos , Cuk Mirjana , Igic Dusan , Igic Ruzica , Orlovic Sasa
Published: April 2016

This study was carried out on the Vidlic Mountain, eastern Serbia. The herb
layer was surveyed in permanent plots on two localities: in a naturally
regenerated beech forest and in a Douglas-fir plantation, in spring, summer
and autumn 2011, 2012 and 2013. Air temperature, air humidity and soil
moisture were measured. Species richness, Shannon?s diversity index and
Pielou?s evenness index were calculated for each plot. Comparison of the
abundances of species common to both forest stands was done using the
Mann-Whitney U-test. The compositional gradient of the species data was
examined using detrended correspondence analysis (DCA), and the
species-environment relationship was analyzed by canonical correspondence
analysis (CCA). Soil moisture and the total herb cover significantly differed
in the naturally regenerated beech forest and Douglas-fir plantation.
Floristic similarity between the surveyed forest stands was 28.12%. Although
the dominant canopy species is known to be the strongest predictor of the
herb layer, the model that includes all of the analyzed environmental factors
explains the largest amount of the species variability. The species best
fitted to this model are Dryopteris filix-mas, Galium odoratum, Pulmonaria
officinalis, Sanicula europaea, Pteridium aquilinum and Rubus caesius. The
analyzed forest stands are examples of two different post-disturbance
regeneration strategies. Having in mind the limitations of this study, we can
conclude that the naturally regenerated beech forest recovers faster: its
herbaceous layer indicated nearly natural conditions, with only a few pioneer
and disturbance-tolerant species. The herb layer in the Douglas-fir stand is
still in the early seral stage, i.e. establishment.
Biological aspects of salivary hormones in male half-marathon performance
Authors: Radosavljevic Branimir , Zarkovic Milos , Ignjatovic Svetlana , Dajak Marijana , Milinkovic Neda
Published: April 2016

Physical effort is known to alter the blood levels of many hormones, but
there are only a few studies about the biological changes of salivary
hormones. The aim of this work was to determine whether salivary testosterone
and salivary cortisol levels, measured two weeks before a half-marathon race,
relate to running performance in male recreational athletes. A group of
eleven male recreational athletes preparing for a half-marathon was included
in the study. Saliva for testosterone and cortisol determinations was
collected before and immediately after a 15-km training run, two weeks before
the half-marathon. Individual official half-marathon times, expressed in
hours, were used as a measure of performance. Mean testosterone
concentrations were 1.07?0.33 nmol/L before the run and 0.88?0.35 nmol/L
after the run (p<0.05). Mean cortisol concentrations were 12.28?8.46 nmol/L
before the run and 38.08?19.63 nmol/L after the run (p<0.05). The pre-run
salivary testosterone levels marginally correlated with the corresponding
half-marathon running times (p=0.068, 95% bootstrap CI for slope -0.40 to
-0.06). However, post-run salivary testosterone levels significantly
correlated with the corresponding half-marathon running times (p=0.011, 95%
bootstrap CI for slope -0.41 to -0.16), even considering correlations with
the runners? age. Salivary cortisol levels, either pre- or post-run, did not
correlate with the corresponding half-marathon running times. The results of
this study suggest that post-exercise salivary testosterone levels could have
the potential to predict performance in endurance running, at least in
recreational athletes.
Environmental screening for microorganisms of patient’s surrounding as the possible source of nosocomial infections in a hospital in Nepal
Authors: Pant Narayan Dutt , Sharma Manisha
Published: April 2016

No Abstract Available.J. Biomed. Sci. 2015, 2(3):21-23.
L'apprentissage organisationnel dans les coopérations
Authors: Ingham Marc
Published: April 2016

Leader mondial dans son secteur, la société Alpha, basée en Europe, produit et commercialise des équipements de pointe. En analysant cinq cas concrets de coopération entre cette entreprise et différents partenaires étrangers, l'auteur s'interroge d'une part, sur le rôle de l'apprentissage organisationnel en tant que motivation pour établir de tels accords ; d'autre part, il se demande comment orienter les processus d'apprentissage au fur et à mesure de la réalisation des projets en cours afin de maximiser leur utilité pour l'entreprise. Il aboutit, en conclusion, à une remarque moins paradoxale qu'il n'y paraît : les acquisitions de connaissances attendues dès l'origine des accords de coopération ont bien lieu, mais s'avèrent difficiles à transférer dans l'organisation, alors que les apprentissages inattendus peuvent être rapidement valorisés à travers le développement d'équipements mais aussi de meilleures pratiques de gestion.
Thinking on Film: Jaspers, Scholem, and Thinking in Margarethe von Trotta’s Hannah Arendt
Authors: Babich Babette
Published: April 2016

Margarethe von Trotta’s 2013 film Hannah Arendt, starring Barbara
Sukowa as Hannah Arendt raises sociopolitical and specifically philosophical
questions in the contentious context of Arendt’s 1963 book Eichmann in
Jerusalem.2 The film itself generated both sociopolitical and philosophical
controversy. At the same time, the overwhelming majority of both popular
and academic responses to the film have tended to focus on the controversy
surrounding the subtitle of Arendt’s original book —A Report on the Banality
of Evil.3 Even accounts inclined to praise the film emphatically criticize
Arendt on the matter of Eichmann in Jersualem. I will here seek to speak
about thinking.
Characterization and Clinical Trial of an Innovative High-Speed Lancing Device
Authors: Chang Ho , Yeh Yao-Jen , Lee Rahnfong , Lee Chia-Chun , Shyu Jenq-Huey
Published: April 2016

An innovative high-speed lancing device has a lancet that moves so fast that it is not affected at all by the vibration of its spring, and does not pierce the skin repeatedly, greatly reducing the pain that is caused to diabetes mellitus (DM) patients during blood sampling. As revealed by experimental measurements of the acceleration of a lancet using an accelerometer, the lancet pierces the skin only once. The maximum acceleration and the instant piercing velocity of the lancet are 9.4 times and 1.78 times those of a conventional lancing device, respectively. Meanwhile, the period for which the lancet remains in the skin is 0.014 s shorter than that of the conventional lancing device. A clinical trial that involved 100 participants yielded statistical results concerning the numeric rating of pain scale (NRS) of pain intensity, which is internationally recognized as the pain with the highest validity, that showed that the NRS of participants who used the innovative high-speed lancing device was 2.65 less than that of those who used the conventional lancing device, and the duration of the pain after blood sampling was 76.1 min shorter.
Experimental Evaluation of a Paraffin as Phase Change Material for Thermal Energy Storage in Laboratory Equipment and in a Shell-and-Tube Heat Exchanger
Authors: Gasia Jaume , Miró Laia , De Gracia Alvaro , Barreneche Camila , Cabeza Luisa
Published: April 2016

The thermal behavior of a commercial paraffin with a melting temperature of 58 °C is analyzed as a phase change material (PCM) candidate for industrial waste heat recovery and domestic hot water applications. A full and complete characterization of this PCM is performed based on two different approaches: a laboratory characterization (mass range of milligrams) and an analysis in a pilot plant (mass range of kilograms). In the laboratory characterization, its thermal and cycling stability, its health hazard as well as its phase change thermal range, enthalpy and specific heat are analyzed using a differential scanning calorimeter, thermogravimetric analysis, thermocycling and infrared spectroscopy. Laboratory analyses showed its suitability up to 80 °C and for 1200 cycles. In the pilot plant analysis, its thermal behavior was analyzed in a shell-and-tube heat exchanger under different heat transfer fluid mass flow rates in terms of temperature, power and energy rates. Results from the pilot plant analysis allowed understanding the different methods of heat transfer in real charging and discharging processes as well as the influence of the geometry of the tank on the energy transferred and required time for charging and discharging processes.
The Mediatorless Electroanalytical Sensing of Sulfide Utilizing Unmodified Graphitic Electrode Materials
Authors: Thakur Bhawana , Bernalte Elena , Smith Jamie , Linton Patricia , Sawant Shilpa , Banks Craig. , Foster Christopher
Published: April 2016

The mediatorless electroanalytical sensing of sulfide is explored at a range of commercially available graphitic based electrodes namely, edge and basal plane pyrolytic graphite (EPPGE and BPPGE, respectively), boron-doped diamond (BDDE), glassy carbon (GCE) and screen-printed electrodes (SPE). The electrochemical performance is evaluated in terms of current density/analytical signal and oxidation potential, where the GCE and SPE are found to possess the optimal electrochemical responses. The electroanalytical performance of the GCE is explored towards the electrochemical sensing of sulfide and it is found that it is hampered by sulfide passivation, thus requiring pretreatment in the form of electrode polishing between each measurement. We demonstrate that SPEs provide a simple analytically comparable alternative, which, due to their scales of economy, create disposable, one-shot sensors that do not require any pretreatment of the electrode surface. To the best of our knowledge, this is the first report using mediatorless SPEs (bare/unmodified) towards the sensing of sulfide. In addition, the electroanalytical efficacy of the SPEs is also explored towards the detection of sulfide within model aqueous solutions and real drinking water samples presenting good apparent recoveries, justifying the plausibility of this graphitic mediatorless screen-printed platform.
Vimentin in Bacterial Infections
Authors: Mak Tim , Brüggemann Holger
Published: April 2016

Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial virulence factors that target vimentin to subvert its function in order to change the host cell fate in the course of a bacterial infection.
Spatio-Temporal Extension and Spatial Analyses of Dengue from Rawalpindi, Islamabad and Swat during 2010–2014
Authors: Fareed Nadeem , Ghaffar Abdul , Malik Tahir
Published: April 2016

Climate change and Land-Use Land-Cover change (LULC) has significantly displaced the local rainfall patterns and weather conditions in Pakistan. This has resulted in a different climate-related problem, particularly vector borne diseases. Dengue transmission has emerged as one of the most devastating and life threatening disease in Pakistan, causing hundreds of deaths since its first outbreak. This study is designed to understand and analyze the disease patterns across two distinct study regions, using Geographic Information System (GIS), Satellite Remote Sensing (RS) along with climate and socio-economic and demographics datasets. The datasets have been analyzed by using GIS statistical analysis techniques. As a result, maps, tables and graphs have been plotted to estimate the most significant parameters. These parameters have been assigned a contribution weight value to prepare a model and Threat Index Map (TIM) for the study areas. Finally, the model has been tested and verified against existing datasets for both study areas. This model can be used as a disease Early Warning System (EWS).
Analysis of Longitudinal Waves in Rod-Type Piezoelectric Phononic Crystals
Authors: Li Longfei , Guo Yongqiang
Published: April 2016

Phononic crystals can be used to control elastic waves due to their frequency bands. This paper analyzes the passive and active control as well as the dispersion properties of longitudinal waves in rod-type piezoelectric phononic crystals over large frequency ranges. Based on the Love rod theory for modeling the longitudinal wave motions in the constituent rods and the method of reverberation-ray matrix (MRRM) for deriving the member transfer matrices of the constituent rods, a modified transfer matrix method (MTMM) is proposed for the analysis of dispersion curves by combining with the Floquet–Bloch principle and for the calculation of transmission spectra. Numerical examples are provided to validate the proposed MTMM for analyzing the band structures in both low and high frequency ranges. The passive control of longitudinal-wave band structures is studied by discussing the influences of the electrode’s thickness, the Poisson’s effect and the elastic rod inserts in the unit cell. The influences of electrical boundaries (including electric-open, applied electric capacity, electric-short and applied feedback control conditions) on the band structures are investigated to illustrate the active control scheme. From the calculated comprehensive frequency spectra over a large frequency range, the dispersion properties of the characteristic longitudinal waves in rod-type piezoelectric phononic crystals are summarized.
Progress in Finite Time Thermodynamic Studies for Internal Combustion Engine Cycles
Authors: Ge Yanlin , Chen Lingen , Sun Fengrui
Published: April 2016

On the basis of introducing the origin and development of finite time thermodynamics (FTT), this paper reviews the progress in FTT optimization for internal combustion engine (ICE) cycles from the following four aspects: the studies on the optimum performances of air standard endoreversible (with only the irreversibility of heat resistance) and irreversible ICE cycles, including Otto, Diesel, Atkinson, Brayton, Dual, Miller, Porous Medium and Universal cycles with constant specific heats, variable specific heats, and variable specific ratio of the conventional and quantum working fluids (WFs); the studies on the optimum piston motion (OPM) trajectories of ICE cycles, including Otto and Diesel cycles with Newtonian and other heat transfer laws; the studies on the performance limits of ICE cycles with non-uniform WF with Newtonian and other heat transfer laws; as well as the studies on the performance simulation of ICE cycles. In the studies, the optimization objectives include work, power, power density, efficiency, entropy generation rate, ecological function, and so on. The further direction for the studies is explored.
Mixed Diffusive-Convective Relaxation of a Warm Beam of Energetic Particles in Cold Plasma
Authors: Carlevaro Nakia , Milovanov Alexander , Falessi Matteo , Montani Giovanni , Terzani Davide , Zonca Fulvio
Published: April 2016

This work addresses the features of fast particle transport in the bump-on-tail problem for varying the width of the fluctuation spectrum, in the view of possible applications to studies of energetic particle transport in fusion plasmas. Our analysis is built around the idea that strongly-shaped beams do not relax through diffusion only and that there exists an intermediate time scale where the relaxations are convective (ballistic-like). We cast this idea in the form of a self-consistent nonlinear dynamical model, which extends the classic equations of the quasi-linear theory to “broad” beams with internal structure. We also present numerical simulation results of the relaxation of a broad beam of energetic particles in cold plasma. These generally demonstrate the mixed diffusive-convective features of supra-thermal particle transport essentially depending on nonlinear wave-particle interactions and phase-space structures. Taking into account the modes of the stable linear spectrum is crucial for the self-consistent evolution of the distribution function and the fluctuation intensity spectrum.
Exploration of Quantum Interference in Document Relevance Judgement Discrepancy
Authors: Wang Benyou , Zhang Peng , Li Jingfei , Song Dawei , Hou Yuexian , Shang Zhenguo
Published: April 2016

Quantum theory has been applied in a number of fields outside physics, e.g., cognitive science and information retrieval (IR). Recently, it has been shown that quantum theory can subsume various key IR models into a single mathematical formalism of Hilbert vector spaces. While a series of quantum-inspired IR models has been proposed, limited effort has been devoted to verify the existence of the quantum-like phenomenon in real users’ information retrieval processes, from a real user study perspective. In this paper, we aim to explore and model the quantum interference in users’ relevance judgement about documents, caused by the presentation order of documents. A user study in the context of IR tasks have been carried out. The existence of the quantum interference is tested by the violation of the law of total probability and the validity of the order effect. Our main findings are: (1) there is an apparent judging discrepancy across different users and document presentation orders, and empirical data have violated the law of total probability; (2) most search trials recorded in the user study show the existence of the order effect, and the incompatible decision perspectives in the quantum question (QQ) model are valid in some trials. We further explain the judgement discrepancy in more depth, in terms of four effects (comparison, unfamiliarity, attraction and repulsion) and also analyse the dynamics of document relevance judgement in terms of the evolution of the information need subspace.
A Quantum Query Expansion Approach for Session Search
Authors: Zhang Peng , Li Jingfei , Wang Benyou , Zhao Xiaozhao , Song Dawei , Hou Yuexian , Melucci Massimo
Published: April 2016

Recently, Quantum Theory (QT) has been employed to advance the theory of Information Retrieval (IR). Various analogies between QT and IR have been established. Among them, a typical one is applying the idea of photon polarization in IR tasks, e.g., for document ranking and query expansion. In this paper, we aim to further extend this work by constructing a new superposed state of each document in the information need space, based on which we can incorporate the quantum interference idea in query expansion. We then apply the new quantum query expansion model to session search, which is a typical Web search task. Empirical evaluation on the large-scale Clueweb12 dataset has shown that the proposed model is effective in the session search tasks, demonstrating the potential of developing novel and effective IR models based on intuitions and formalisms of QT.
Numerical Simulation of Williamson Combined Natural and Forced Convective Fluid Flow between Parallel Vertical Walls with Slip Effects and Radiative Heat Transfer in a Porous Medium
Authors: Abdollahzadeh Jamalabadi Mohammad , Hooshmand Payam , Bagheri Navid , KhakRah HamidReza , Dousti Majid
Published: April 2016

Numerical study of the slip effects and radiative heat transfer on a steady state fully developed Williamson flow of an incompressible Newtonian fluid; between parallel vertical walls of a microchannel with isothermal walls in a porous medium is performed. The slip effects are considered at both boundary conditions. Radiative highly absorbing medium is modeled by the Rosseland approximation. The non-dimensional governing Navier–Stokes and energy coupled partial differential equations formed a boundary problem are solved numerically using the fourth order Runge–Kutta algorithm by means of a shooting method. Numerical outcomes for the skin friction coefficient, the rate of heat transfer represented by the local Nusselt number were presented even as the velocity and temperature profiles illustrated graphically and analyzed. The effects of the temperature number, Grashof number, thermal radiation parameter, Reynolds number, velocity slip length, Darcy number, and temperature jump, on the flow field and temperature field and their effects on the boundaries are presented and discussed.
Impact of Biodiesel Blends and Di-Ethyl-Ether on the Cold Starting Performance of a Compression Ignition Engine
Authors: Clenci Adrian , Niculescu Rodica , Danlos Amélie , Iorga-Simăn Victor , Trică Alina
Published: April 2016

The use of biodiesel fuel in compression ignition engines has the potential to reduce CO2, which can lead to a reduction in global warming and environmental hazards. Biodiesel is an attractive fuel, as it is made from renewable resources. Many studies have been conducted to assess the impact of biodiesel use on engine performances. Most of them were carried out in positive temperature conditions. A major drawback associated with the use of biodiesel, however, is its poor cold flow properties, which have a direct influence on the cold starting performance of the engine. Since diesel engine behavior at negative temperatures is an important quality criterion of the engine’s operation, one goal of this paper is to assess the starting performance at −20 °C of a common automotive compression ignition engine, fueled with different blends of fossil diesel fuel and biodiesel. Results showed that increasing the biodiesel blend ratio generated a great deterioration in engine startability. Another goal of this study was to determine the biodiesel blend ratio limit at which the engine would not start at −20 °C and, subsequently, to investigate the impact of Di-Ethyl-Ether (DEE) injection into the intake duct on the engine’s startability, which was found to be recovered.
High Pressure Oxydesulphurisation of Coal Using KMnO4—Effect of Coal Slurry Concentration, pH and Alkali
Authors: Ghauri Moinuddin , Shahzad Khurram , Inayat Abrar , Ali Zulfiqar , Cliffe Keith
Published: April 2016

A high pressure oxydesulphurisation technique was investigated to reduce sulphur content, especially at ambient temperature. Prince of Wales coal was chosen for this study. The focus of the study was on the reduction of both pyritic and organic sulphur. The effects of pressure, coal slurry concentration, pH and KOH concentration in a fixed time interval on sulphur removal were studied with a series of experimental runs at ambient temperature. Heating value recovery was found to be increased with decreased pressure and with increased coal slurry concentration. It was found that sulphur removal was enhanced with an increase in pressure, with a more significant effect on the organic sulphur. With increase in the coal slurry concentration reduction, sulphur was found to be decreased.
A Method for Assessing the Performance of e-Government Twitter Accounts
Authors: Antoniadis Konstantinos , Zafiropoulos Kostas , Vrana Vasiliki
Published: April 2016

This paper introduces a method for assessing the influence of Twitter accounts of central e-government agencies. It first stresses the importance of activity and popularity of the e-government accounts, and also the importance of community formation among followers-citizens, as the two main stages of e-government adoption. The proposed approach combines activity and popularity of the accounts and followers’ community characteristics in a ranking system, using an idea originally introduced to measure blogosphere authority. A Twitter Authority Index is produced. The method is demonstrated through an extended example: 56 Twitter accounts of ministries of EU countries are sorted according to their indexes in the proposed ranking system. Detailed values for the ministries’ accounts and average values for the countries that the ministries belong to are reported and commented.
Food Safety Impacts from Post-Harvest Processing Procedures of Molluscan Shellfish
Authors: Baker George
Published: April 2016

Post-harvest Processing (PHP) methods are viable food processing methods employed to reduce human pathogens in molluscan shellfish that would normally be consumed raw, such as raw oysters on the half-shell. Efficacy of human pathogen reduction associated with PHP varies with respect to time, temperature, salinity, pressure, and process exposure. Regulatory requirements and PHP molluscan shellfish quality implications are major considerations for PHP usage. Food safety impacts associated with PHP of molluscan shellfish vary in their efficacy and may have synergistic outcomes when combined. Further research for many PHP methods are necessary and emerging PHP methods that result in minimal quality loss and effective human pathogen reduction should be explored.
Hepatotoxicity Induced by “the 3Ks”: Kava, Kratom and Khat
Authors: Pantano Flaminia , Tittarelli Roberta , Mannocchi Giulio , Zaami Simona , Ricci Serafino , Giorgetti Raffaele , Terranova Daniela , Busardò Francesco , Marinelli Enrico
Published: April 2016

The 3Ks (kava, kratom and khat) are herbals that can potentially induce liver injuries. On the one hand, growing controversial data have been reported about the hepatotoxicity of kratom, while, on the other hand, even though kava and khat hepatotoxicity has been investigated, the hepatotoxic effects are still not clear. Chronic recreational use of kratom has been associated with rare instances of acute liver injury. Several studies and case reports have suggested that khat is hepatotoxic, leading to deranged liver enzymes and also histopathological evidence of acute hepatocellular degeneration. Numerous reports of severe hepatotoxicity potentially induced by kava have also been highlighted, both in the USA and Europe. The aim of this review is to focus on the different patterns and the mechanisms of hepatotoxicity induced by “the 3Ks”, while trying to clarify the numerous aspects that still need to be addressed.