bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of number of injections on mechanical properties of sandstone cemented with microbe cement
Authors: Rong Hui , Qian Chunxiang , Li Longzhi
Published: March 2013

Microbe cement, as a new green binder, relies on microbial-induced calcium carbonate precipitation and could consolidate loose particles to a whole body (bio-sandstone). The mechanical properties of sandstone cemented by microbe cement for different numbers of injections were investigated. The results show that the compressive strength of bio-sandstones increases with injection number: the average compressive strength of bio-sandstones could be up to 6·1 MPa after 14 injections of microbe cement. In addition, the rate of increase of compressive strength decreases with an increase in the number of injections. The microstructure of bio-sandstones with different numbers of injections was analysed by means of scanning electron microscopy. The results indicate that the microstructure of the bio-sandstones became increasingly dense with an increase in microbe cement injections.
Plant life-cycle information management in nuclear new build
Authors: Tan Loh Koon , Gibbels Rolf
Published: March 2013

This paper considers the challenges to the UK nuclear programme, such as data integration across the project life cycle and a limited skilled workforce, and presents a point of view and strategy for future new build projects. A systems integration approach is suggested to help the industry meet the safety, programme, budgetary and quality needs of this major infrastructure programme. This integrated platform approach, called Plant Lifecycle Information Management (PlantLIM), is designed to manage the transition of data across the design, construction, commissioning, and operation phases of the plant life cycle, thus maintaining data quality and integrity through the life of the plant. Data relate to: (a) process, with robust configuration management to maintain design control through the plant life cycle; (b) technology, with configuration management information systems for a single version of the truth, clear requirements management and traceability; (c) collaboration, where construction control centres are provided for supply chain collaboration; and (d) resource optimisation, comprising technology-based solutions to make best use of a limited workforce. Although the focus is on new build, the approach is equally relevant to plant life extensions and on-site projects.
Laboratory evaluation of geocell-reinforced gravel subbase over poor subgrades
Authors: Tanyu B.F. , Aydilek A.H. , Lau A.W. , Edil T.B. , Benson C.H.
Published: March 2013

ABSTRACT: Large-scale experiments with cyclic loading were conducted to determine how incorporation of high-density polyethylene (HDPE) geocells affects the rutting properties of working platforms and resilient properties of a subbase in a pavement structure over soft subgrades. Four different geocells were used in this study to reinforce common subbase/base course gravel. Experiments were performed with 225 mm and 450 mm thick unreinforced and reinforced gravel and a crushed rock that is typically used for conventional cut-and-fill working platforms. Experiments were conducted to simulate loading conditions both during construction due to construction equipment and after construction due to traffic conditions over the asphalt pavement once the pavement structure is constructed. Materials used in this study were compacted to 90% relative compaction based on standard Proctor to determine the effect of geocells specifically with gravel material that is compacted to lower than typical standards. Deflections, modulus of subgrade reaction and resilient modulus of each section were evaluated. In summary, presence of geocells reduced the plastic deflection of the working platforms by 30–50%, improved the resilient modulus of the subbase by 40–50%, and the modulus of subgrade reaction by more than 2 times.
Stimulatory Effects of Glucose and Porphyromonas gingivalis Lipopolysaccharide on the Secretion of Inflammatory Mediators From Human Macrophages
Authors: Hung Shan‐Ling , Lee Nin‐Gi , Chang Lien‐Yu , Chen Yen‐Ting , Lai Yu‐Lin
Published: March 2013

Background: Hyperglycemia is widely considered to be the causal link between diabetes mellitus (DM) and diabetic complications. The purpose of this study is to determine the effects of high glucose in the presence of lipopolysaccharide (LPS) purified from the periodontal pathogen Porphyromonas gingivalis on human macrophages.

Methods: Macrophages (U937) were treated with various concentrations of P. gingivalis–LPS under normal (5.5 mM) or high (25 mM) glucose conditions. Mitochondrial dehydrogenase activity was determined using the 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5 diphenyltetrazolium bromide assay. The levels of inflammatory mediators secreted were determined using the enzyme‐linked immunosorbent assay and the competitive enzyme immunoassay. The intracellular calcium chelator was used to examine whether the intracellular calcium was involved. Statistical differences were assessed using a one‐way analysis of variance and Tukey multiple‐comparison intervals with α = 0.05.

Results: High glucose condition enhanced the mitochondrial dehydrogenase activity in macrophages. P. gingivalis–LPS induced the secretion of interleukin (IL)‐6, tumor necrosis factor (TNF)‐α, and prostaglandin E2 (PGE2) in a dose‐dependent manner both in normal and high glucose conditions. The stimulatory effects by P. gingivalis–LPS were more evident when cells were cultured under high glucose conditions. Changes of intracellular calcium concentration were involved not only in high glucose–induced mitochondrial dehydrogenase activity but also in P. gingivalis–LPS‐induced production of IL‐6, TNF‐α, or PGE2, especially under the high glucose conditions.

Conclusions: High glucose appeared to enhance the inflammatory response induced by the periodontal pathogen. The information generated may help to delineate the possible mechanisms by which hyperglycemia compromises the periodontal health of patients with DM.
A New Environmentally Friendly Clay Stabilizer
Authors: El-Monier I.A.. A. , Nasr-El-Din H.A.. A. , Harper T.L.. L. , Rosen R..
Published: March 2013

Clay stabilizers are used to prevent fines migration and clay swelling, which are caused by the contact of clays with low salinity or high pH fluids. Previously used clay stabilizers, including hydroxy-aluminum, zirconium oxychloride solutions, and cationic polymers have several drawbacks. Hydroxy-aluminum and zirconium oxychloride solutions can be leached by acids (Coppel et al. 1973). Cationic organic polymers can cause formation damage in some cases (Nasr-El-Din et al. 1999). Their environmental impact is also questionable (Patel 2009). There is a need to develop new clay stabilizers that can work with acid treatments and that are environmentally acceptable.

Laboratory studies were conducted on a newly developed inorganic aluminum/zirconium-based compound. Coreflood experiments were conducted on Berea sandstone cores (1.5 in. in diameter, 6 and 20 in. in length) to assess the effectiveness of the new compound at high temperatures and determine the impact of acids on its performance. Inductively coupled plasma was used to measure the concentrations of aluminum and zirconium in the coreflood effluent samples.

The new clay stabilizer was very effective in mitigating fines migration. Experimental results showed that unlike previous Al/Zr compounds, the new stabilizer was effective even after using several 15 wt% HCl acid washes. In addition, it did not cause formation damage, and worked very well up to 300°F. It is non-toxic, with no smell, and environmentally friendly.
Prediction Performance of Permeability Models in Gas-Hydrate-Bearing Sands
Authors: Delli Mohana L. , Grozic Jocelyn L.H.
Published: March 2013

Permeability variation in the presence of gas hydrates (GH) is a major unknown in modeling hydrate dissociation in gas-hydrate-bearing sediment. Reduction of permeability in porous media occurs as a result of decreased porosity because of hydrate formation within pore spaces. In the absence of reliable experimental data, theoretical and empirical models have been proposed to establish the relationship between gas-hydrate saturation and permeability. The effectiveness of a particular permeability model in fitting the measured data has largely been qualitative through graphical analysis. In contrast, this paper introduces a quantitative performance measure to evaluate the effectiveness of an individual model in predicting the measured permeability. Second, a hybrid approach based on the weighted combination of existing permeability models is proposed. Permeability measurements from experimental and field studies were used to assess the prediction performance of various permeability models and the proposed hybrid approach.
Dynamic Capillary Pressure Curves From Pore-Scale Modeling in Mixed-Wet-Rock Images
Authors: Zhou Y.. , Helland J.O.. O. , Jettestuen E..
Published: March 2013

In reservoir multiphase-flow processes with high flow rates, both viscous and capillary forces determine the pore-scale fluid configurations, and significant dynamic effects could appear in the capillary pressure/saturation relation. We simulate dynamic and quasistatic capillary pressure curves for drainage and imbibition directly in scanning-electron-microscope (SEM) images of Bentheim sandstone at mixed-wet conditions by treating the identified pore spaces as tube cross sections. The phase pressures vary with length positions along the tube length but remain unique in each cross section, which leads to a nonlinear system of equations that are solved for interface positions as a function of time. The cross-sectional fluid configurations are computed accurately at any capillary pressure and wetting condition by combining free-energy minimization with a menisci-determining procedure that identifies the intersections of two circles moving in opposite directions along the pore boundary. Circle rotation at pinned contact lines accounts for mixed-wet conditions. Dynamic capillary pressure is calculated with volume-averaged phase pressures, and dynamic capillary coefficients are obtained by computing the time derivative of saturation and the difference between the dynamic and static capillary pressure. Consistent with previously reported measurements, our results demonstrate that, for a given water saturation, simulated dynamic capillary pressure curves are at a higher capillary level than the static capillary pressure during drainage, but at a lower level during imbibition, regardless of the wetting state of the porous medium. The difference between dynamic and static capillary pressure becomes larger as the pressure step applied in the simulations is increased. The model predicts that the dynamic capillary coefficient is a function of saturation and is independent of the incremental pressure step, which is consistent with results reported in previous studies. The dynamic capillary coefficient increases with decreasing water saturation at water-wet conditions, whereas, for mixed- to oil-wet conditions, it increases with increasing water saturation. The imbibition simulations performed at mixed- to oil-wet conditions also indicate that the dynamic capillary coefficient increases with decreasing initial water saturation.

The proposed modeling procedure provides insights into the extent of dynamic effects in capillary pressure curves for realistic mixed-wet pore spaces, which could contribute to the improved interpretation of core-scale experiments. The simulated capillary pressure curves obtained with the pore-scale model could also be applied in reservoir-simulation models to assess dynamic pore-scale effects on the Darcy scale.
Geology and Geohistory Contribute to Flow Assurance
Authors: Yonebayashi Hideharu , Tosic Slavko , O'Brien Dennis R.
Published: March 2013

This paper presents information regarding past traditional flow-assurance analyses at an example field, along with an example using a new multidisciplinary method that integrates geological information into the analyses, resulting in a detailed asphaltene matrix risk profile for this reservoir.

During the past asphaltene flow-assurance risk assessment, the traditional analyses have revealed some anomalous results such as asphaltene onset pressure (AOP) being detected from some fluid samples while not being detected from others. The apparently inconsistent AOP results are critical to understanding how to guide flow-assurance measures. Therefore, all available asphaltene data were re-assessed in all aspects to attempt to clarify asphaltene risk.

Asphaltene issues have often been discussed by multidisciplinary teams consisting of petrophysicists and engineers with well, production, reservoir, chemical, or pipeline backgrounds because such multidisciplinary approaches can deliver fresh eyes to redefine problems. This paper, as a new approach, demonstrates the worth of uniting a further discipline, geoscience, with flow assurance. A synergy between reservoir engineering and geoscience (geology and geohistory) has been developed to explain AOP results for this complex fluid. The results should help flow-assurance specialists to better define the asphaltene operating envelope, which will be used for reservoir and production operations optimization. In addition, these results should be useful for optimizing data surveillance, flow assurance, and for defining new sample acquisition plans. These findings may also be helpful in minimizing future sampling and fluids analysis while achieving reliable flow assurance.
A New Approach for Predicting Inhibited Erosion-Corrosion in CO2-Saturated Oil/Brine Flow Condition
Authors: Hassani Shokrollah , Roberts Kenneth P. , Shirazi Siamack A. , Rybicki Edmund F. , Shadley John R. , Joia C..
Published: March 2013

Chemical inhibition is a common method for controlling erosion-corrosion in offshore mild steel pipelines, tubing and pipe fittings. This paper introduces a new approach for predicting inhibited erosion-corrosion in mild steel pipes, including the effects of flow and environmental conditions, sand production, and an oil phase. When sand is produced, sand particle impingement on piping surfaces can decrease the efficiency of corrosion protection systems, such as iron-carbonate scale formation or chemical inhibition, and can result in severe corrosion and even pitting. The need to be able to predict inhibitor performance under sand-production conditions is particularly acute when the wells are deep or offshore because of the difficulty in running coupon tests to evaluate the inhibitor efficiency at critical points throughout a system. The research reported in this paper is aimed at providing producers with information that will help them make decisions on the design of the well given advanced knowledge of the inhibition options and their predicted effectiveness under sand-production conditions. Inhibition mechanisms and the relation between inhibitor concentration and inhibitor coverage are described using adsorption isotherms. The Frumkin isotherm showed the best fit to experimental data for an imidazoline-based inhibitor used in sand-free conditions. Flow-loop tests indicated that sand particle erosion decreased the efficiency of the inhibitor. However, Frumkin isotherms modified to handle effects of erosivity, temperature, and oil phase were successfully fitted to erosion-corrosion data. Inhibitor adsorption isotherms, for both sand-free and sand-production conditions, were integrated into a mechanistic model for prediction of CO2 corrosion rates as a function of inhibitor concentration, and good results were obtained when compared with data.

Results of this study show that the inhibitor adsorption isotherm, modified to handle effects of sand production, temperature, and oil phase, can be a valuable tool for predicting inhibited metal loss rates under sand-production conditions.
The impact of liquidity and size premium on equity price formation in Serbia
Authors: Minovic Jelena , Zivkovic Bosko
Published: March 2013

The goal of this paper is to examine the impact of an overall market factor,
the factor related to the firm size, the factor related to the ratio of book
to market value of companies, and the factor of liquidity risk on expected
asset returns in the Serbian market. For this market we estimated different
factor models: Capital Asset Pricing Model (CAPM by Sharpe, 1964),
Fama-French (FF) model (1992, 1993), Liquidity-augmented CAPM (LCAPM) by Liu
(2006), and combination LCAPM with FF factors. We used daily data for the
period from 2005 to 2009. Using a demanding methodology and complex dataset,
we found that liquidity and firm size had a significant impact on equity
price formation in Serbia. On the other hand, our results suggest that the
factor related to the ratio of book to market value of companies does not
have an important role in asset pricing in Serbia. We found that Liu?s two
factor LCAPM model performs better in explaining stock returns than the
standard CAPM and the Fama-French three factor model. Additionally, Liu?s
LCAPM may indeed be a good tool for realistic assessment of the expected
asset returns. The combination of the Fama-French model and the LCAPM could
improve the understanding of equilibrium in the Serbian equity market. Even
though previous papers have mostly dealt with examining different factor
models of developed or emerging markets worldwide, none of them has tested
factor models on the countries of former Yugoslavia. This paper is the first
to test the FF model and LCAPM with FF factors in the case of Serbia and the
area of ex-Yugoslavia.
Power, Information and Control: School Statistics and the Spanish Educational System (Nineteenth Century and First Third of the Twentieth Century)
Authors: Guereña Jean-Louis , Viñao Antonio
Published: March 2013

In this article, the authors investigate the relationship between the development of school statistics, especially in the area of primary education, and the development of the Spanish educational system in the nineteenth century and the first third of the twentieth century. To do this, they first look at attempts to gather statistical information on education and to provide general figures on education in Spain that took place under the absolute monarchy during the eighteenth century and the first third of the nineteenth century. They then analyse in a little more detail the long journey undertaken by the new liberal regime between 1834 and 1850 — during which years the Spanish education system would be built — to know the educational situation in the country and have steady, regular, reliable school statistics. What can be considered the golden age of school statistics (1855–1885) followed, when this project was realised. Finally, they discuss the characteristics and evolution of occasional school statistics produced during the last years of the nineteenth century and the first third of the twentieth century.
Fasting Plasma Glucose at 24–28 Weeks to Screen for Gestational Diabetes Mellitus
Authors: Zhu Wei-wei , Fan Ling , Yang Hui-xia , Kong Ling-ying , Su Shi-ping , Wang Zi-lian , Hu Ya-Li , Zhang Mei-hua , Sun Li-Zhou , Mi Yang , Du Xiu-ping , Zhang Hua , Wang Yun-hui , Huang Yin-ping , Zhong Li-ruo , Wu Hai-rong , Li Nan , Wang Yun-feng , Kapur Anil
Published: March 2013

OBJECTIVE

To evaluate the usefulness of a fasting plasma glucose (FPG) at 24–28 weeks’ gestation to screen for gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

The medical records and results of a 75-g 2-h oral glucose tolerance test (OGTT) of 24,854 pregnant women without known pre-GDM attending prenatal clinics in 15 hospitals in China were examined.

RESULTS

FPG cutoff value of 5.1 mmol/L identified 3,149 (12.1%) pregnant women with GDM. FPG cutoff value of 4.4 mmol/L ruled out GDM in 15,369 (38.2%) women. With use of this cutoff point, 12.2% of patients with mild GDM will be missed. The positive predictive value is 0.322, and the negative predictive value is 0.928.

CONCLUSIONS

FPG at 24–28 weeks’ gestation could be used as a screening test to identify GDM patients in low-resource regions. Women with an FPG between ≥4.4 and ≤5.0 mmol/L would require a 75-g OGTT to diagnose GDM. This would help to avoid approximately one-half (50.3%) of the formal 75-g OGTTs in China.
Prevalence of Staphylococcus aureus in Intensive care Units and Post Operative Ward as a possible source of Nosocomial infection: An experience of tertiary care hospital
Authors: Bhattarai P , Dhungel BA , Shah P , Amatya J
Published: March 2013

Background and Objectives: Hospital Acquired Infection (HAI) also called nosocomial infection is a global problem. It also acts as a leading cause of death and increased morbidity among hospitalized patients. Staphylococcus aureus is one of the commonest pathogens causing HAI and is also closely associated with human body. WHO study has shown highest prevalence of HAI in Intensive care unit (ICU), Neonatal care unit (NICU), Post operative ward (POW). Hence it becomes very imperative to check the prevalence of HAI. Therefore this study was carried out to determine the prevalence of S. aureus in hospital environment as a possible source for HAI. Material and Methods: Environmental samples and blood samples of the patients were collected from ICU, NICU, POW using sterile cotton swabs during study period. Standard protocol was followed to isolate and identify S. aurues which was followed by antibiotic sensitivity tests. Results: A total of 216 environmental samples were collected out of which 18.98% (41) samples showed the presence of S. aureus. It was also isolated from the blood samples of patients admitted to ICU (7.5%) and NICU (6.8%). None of the isolates from environmental samples were MRSA(methycillin resistant Staphylococcus aures). Conclusion: S. aureus was found as a prominent environmental flora of hospital setting. Presence of these organisms in sensitive units like ICU, NICU, POW and the isolation of S. aureus from clinical samples indicates a possibility of HAI. It indicates the necessity of continuous surveillance of hospital environmental for quality control. DOI: http://dx.doi.org/10.3126/jmcjms.v1i1.7882 Janaki Medical College Journal of Medical Sciences (2013) Vol. 1 (1):21-25
Physiology of nostril breathing exercises and its probable relation with nostril and cerebral dominance: A theoretical research on literature
Authors: Upadhyay-Dhungel K , Sohal A
Published: March 2013

This article discuss about scientific basis of benefits of practicing slow pranayama, especially alternate nostril breathing pranayama. It explains the basis of benefit of alternate nostril breathing exercises and its probable relation with nasal cycle, cerebral dominance and autonomic nervous system. The airflow through one nostril is greater than next at any point of time which later switches to another. This is called nasal cycle. The nasal cycle lasts from 30 minutes to 2-3 hours. The nasal cycle occurs naturally. This nasal cycle is related with the cerebral dominance. When one nostril is dominant, the contra lateral hemisphere is active. The right nostril breathing leads to increased sympathetic activity while left nostril breathing decreases sympathetic activity and increases parasympathetic tone. So it has been speculated that these three phenomenon viz. nasal cycle, cerebral dominance and autonomic activities are correlated. This review also suggests that practicing alternate nostril breathing (Nadisodhan pranayma) regularly keeps the two hemispheres active and balances the sympathetic and parasympathetic activities in the body. Sympathetic or parasympathetic activity alternates automatically in our body which is important for our survival. Due to our hectic and stressful life, this naturally occurring alternate breathing cycle gets disrupted and we suffer from different ailments. These ailments are due to imbalance of autonomic nervous system which can be resolved by practicing alternate nostril breathing, the Nadisodhan pranayama. It’s just like returning back to nature. DOI: http://dx.doi.org/10.3126/jmcjms.v1i1.7885 Janaki Medical College Journal of Medical Sciences (2013) Vol. 1 (1):38-47
Prevalence of Pulmonary Tuberculosis among the suspected patients visiting tertiary care hospital in Birgunj, Nepal
Authors: Shrestha S , Shakya B , Shrestha P
Published: March 2013

Background and Objectives: Mycobacterial disease continues to cause high morbidity and mortality and is a major public health problem in Nepal. Bacteriological examination of sputum is the cornerstone in the diagnosis of pulmonary tuberculosis in the developing world. This prospective study was carried out with an objective to evaluate the prevalence of pulmonary tuberculosis among the patients visiting National Medical College Teaching Hospital by Ziehl- Neelsen (Zn) staining microscopy. Material and Methods: The study was cross-sectional study. Three consecutive early morning sputum collected from 626 patients were subjected to Zn staining and observed under oil immersion. Results: Among 626 patients, 85 (13.57%) were found to be Acid fast positive by Zn staining microscopy. Of total suspected patients,16.0% of male and 8.7% of female were infected, common among 41-60 years group (17.2%) followed by 21-40 years (12.6%) and multibacillary cases was 71.8%. Conclusion: The prevalence of pulmonary tuberculosis among National medical college teaching hospital was found to be higher than the Nation pulmonary tuberculosis detection rate, most commonly infecting males. DOI: http://dx.doi.org/10.3126/jmcjms.v1i1.7886 Janaki Medical College Journal of Medical Sciences (2013) Vol. 1 (1):48-52
Modelling the Contribution of Domestic Heat Pumps to Delivering UK Energy Policy Objectives
Authors: Braun David , Rowley Paul
Published: March 2013

The UK Government has ambitious targets for CO2 emissions reductions, particularly for the domestic housing stock. One technology that is expected to contribute significantly is heat pumps, both air and ground source. However, recent field trial results suggest that heat pumps in the UK are not delivering to performance expectations. This paper looks at the implications of these results for the UK housing stock’s future CO2 emissions. The English Housing Condition Survey dataset is used as the basis for a Monte Carlo simulation in order to model CO2 emissions and energy consumption for the whole of English housing stock out to 2050. The results suggest that, given the current UK electricity grid CO2 emission factor, in the short term poor heat pump performance could lead to a rise in emissions where natural gas boilers are displaced. In the longer term, heat pumps can realise emissions reductions when installed at high penetration levels when combined with a grid decarbonisation strategy. Until grid decarbonisation occurs, an alternative phased strategy is proposed that includes phased replacement of resistive electric heating, first in households in fuel poverty and then the remainder of properties with this heating type. Following this phased strategy, real emissions savings are possible along with a potential reduction in fuel poverty.
Antitumor Virotherapy by Attenuated Measles Virus (MV)
Authors: Guillerme Jean-Baptiste , Gregoire Marc , Tangy Frédéric , Fonteneau Jean-François
Published: March 2013

Antitumor virotherapy consists of the use of replication-competent viruses to infect and kill tumor cells preferentially, without damaging healthy cells. Vaccine-attenuated strains of measles virus (MV) are good candidates for this approach. Attenuated MV uses the CD46 molecule as a major entry receptor into cells. This molecule negatively regulates the complement system and is frequently overexpressed by cancer cells to escape lysis by the complement system. MV exhibits oncolytic properties in many cancer types in vitro, and in mouse models. Phase I clinical trials using MV are currently underway. Here, we review the state of this therapeutic approach, with a focus on the effects of MV on the antitumor immune response.
Sea Ice Microorganisms: Environmental Constraints and Extracellular Responses
Authors: Ewert Marcela , Deming Jody
Published: March 2013

Inherent to sea ice, like other high latitude environments, is the strong seasonality driven by changes in insolation throughout the year. Sea-ice organisms are exposed to shifting, sometimes limiting, conditions of temperature and salinity. An array of adaptations to survive these and other challenges has been acquired by those organisms that inhabit the ice. One key adaptive response is the production of extracellular polymeric substances (EPS), which play multiple roles in the entrapment, retention and survival of microorganisms in sea ice. In this concept paper we consider two main areas of sea-ice microbiology: the physico-chemical properties that define sea ice as a microbial habitat, imparting particular advantages and limits; and extracellular responses elicited in microbial inhabitants as they exploit or survive these conditions. Emphasis is placed on protective strategies used in the face of fluctuating and extreme environmental conditions in sea ice. Gaps in knowledge and testable hypotheses are identified for future research.
Analysis of an Air Powered Engine System Using a Multi-Stage Radial Turbine
Authors: Zhang Xuehui , Chen Haisheng , Yan Xiaohui , Zhang Xinjing , Tan Chunqing
Published: March 2013

The performance and design criteria of air powered multistage turbines are studied thermodynamically in this paper. In-house code is developed in the C++ environment and the characteristics of four-stage turbines with inter-heating are analyzed in terms of maximum thermal efficiency, maximum exergy efficiency and maximum work output over the inlet temperature range of 293 K–793 K with inlet pressure of 70 bar. It is found that the maximum thermal efficiency, maximum exergy efficiency and maximum work output are 62.6%, 91.9%, 763.2 kJ/s, respectively. However, the thermal efficiency, exergy efficiency and work output are not equivalent for the four-stage radial turbine. It is suggested that at low working temperatures both maximum exergy efficiency and maximum work output can be used as the design objective, however, only maximum work output can be used as the design objective for the four-stage radial turbine over the working temperature range in this work.
System Design and Analysis of a Directly Air-Assisted Turbocharged SI Engine with Camshaft Driven Valves
Authors: Voser Christoph , Onder Christopher , Guzzella Lino
Published: March 2013

The availability of compressed air in combination with downsizing and turbocharging is a promising approach to improve the fuel economy and the driveability of internal combustion engines. The compressed air is used to boost and start the engine. It is generated during deceleration phases by running the engine as a piston compressor. In this paper, a camshaft-driven valve is considered for the control of the air exchange between the tank and the combustion chamber. Such a valve system is cost-effective and robust. Each pneumatic engine mode is realized by a separate cam. The air mass transfer in each mode is analyzed. Special attention is paid to the tank pressure dependence. The air demand in the boost mode is found to increase with the tank pressure. However, the dependence on the tank pressure is small in the most relevant operating region. The air demand of the pneumatic start shows a piecewise continuous dependence on the tank pressure. Finally, a tank sizing method is proposed which uses a quasi-static simulation. It is applied to a compact class vehicle, for which a tank volume of less than 10 L is sufficient. A further reduction of the tank volume is limited by the specifications imposed on the pneumatic start.
Energy Balance of a Typical U.S. Diet
Authors: Alexandrou Athanasios , Tenbergen Klaus , Adhikari Diganta
Published: March 2013

Today’s agriculture provides an ever increasing population with sufficient quantities of food. During food production, processing, handling and transportation, an amount of energy is invested into the various products. An energy analysis of a typical American diet provides policy makers, farmers and the public with the necessary information to evaluate and make informed decisions as to how to improve the efficient use of energy. At the same time, an informed consumer may become energy conscious and be able to make dietary choices based on food energy balance. This paper studies the energy sequestered in a typical American diet as defined in Food and Agriculture Organization of the United Nations, Statistics Division (FAOSTAT). The amount of energy incorporated in this diet of 3628 kcal (15.18 MJ) per person and day to produce, transport, handle and process the foods is calculated and found to have approximately 39.92 GJ (9.54 Gcal) sequestered per person and year. It is shown that a diet in line with the United States Department of Agriculture (USDA) recommendation of around 2100 kcal (8.79 MJ) per day person will result in a reduction of energy inputs by 42% on an annual basis. This reduction for the whole population of the United States of America (USA), corresponds to approximately 879 million barrels of oil equivalent (boe) savings. Energy efficiency for the food categories studied varies from 3.4% to 56.5% with an average of 21.7%. Food energy efficiency can be further improved in some food categories through either a reduction of energy inputs or yield increase.
From Geoportals to Geographic Knowledge Portals
Authors: Vockner Bernhard , Richter Andreas , Mittlböck Manfred
Published: March 2013

We present the application of Latent Semantic Analysis (LSA) in combination with recommender systems, in order to enhance discovery in geoportals. As a basis for discovery, metadata of spatial data and services, as well as of non-spatial resources, such as documents and scientific papers, is created and registered in the catalogue of the geoportal (semi-)automatically. Links that are not inherent in the data itself are established based on the semantic similarity of its textual content using LSA. This leads to the transition from unstructured data to structured (metadata) information, serving as a basis for the generation of knowledge. The metadata information is integrated into a recommendation system that provides a ranked list showing (1) what other users viewed and (2) the related resources discovered by the LSA workflow as a result. Based on the assumptions that similar texts have something in common and that users are likely to be interested in what other users viewed, recommendations provide a broader, but also more precise, search result; on the one hand, the recommender engine considers additional information; on the other hand, it ranks resources based on the discovery experience of other users and the likeliness of the documents being related to each other.
Genetic Diversity Revealed by Single Nucleotide Polymorphism Markers in a Worldwide Germplasm Collection of Durum Wheat
Authors: Ren Jing , Sun Daokun , Chen Liang , You Frank , Wang Jirui , Peng Yunliang , Nevo Eviatar , Sun Dongfa , Luo Ming-Cheng , Peng Junhua
Published: March 2013

Evaluation of genetic diversity and genetic structure in crops has important implications for plant breeding programs and the conservation of genetic resources. Newly developed single nucleotide polymorphism (SNP) markers are effective in detecting genetic diversity. In the present study, a worldwide durum wheat collection consisting of 150 accessions was used. Genetic diversity and genetic structure were investigated using 946 polymorphic SNP markers covering the whole genome of tetraploid wheat. Genetic structure was greatly impacted by multiple factors, such as environmental conditions, breeding methods reflected by release periods of varieties, and gene flows via human activities. A loss of genetic diversity was observed from landraces and old cultivars to the modern cultivars released during periods of the Early Green Revolution, but an increase in cultivars released during the Post Green Revolution. Furthermore, a comparative analysis of genetic diversity among the 10 mega ecogeographical regions indicated that South America, North America, and Europe possessed the richest genetic variability, while the Middle East showed moderate levels of genetic diversity.
Transcriptional Analysis of Drought-Induced Genes in the Roots of a Tolerant Genotype of the Common Bean (Phaseolus vulgaris L.)
Authors: Recchia Gustavo , Caldas Danielle , Beraldo Ana , Da Silva Márcio , Tsai Siu
Published: March 2013

In Brazil, common bean (Phaseolus vulgaris L.) productivity is severely affected by drought stress due to low technology cultivation systems. Our purpose was to identify differentially expressed genes in roots of a genotype tolerant to water deficit (BAT 477) when submitted to an interruption of irrigation during its development. A SSH library was constructed taking as “driver” the genotype Carioca 80SH (susceptible to drought). After clustering and data mining, 1572 valid reads were obtained, resulting in 1120 ESTs (expressed sequence tags). We found sequences for transcription factors, carbohydrates metabolism, proline-rich proteins, aquaporins, chaperones and ubiquitins, all of them organized according to their biological processes. Our suppressive subtractive hybridization (SSH) library was validated through RT-qPCR experiment by assessing the expression patterns of 10 selected genes in both genotypes under stressed and control conditions. Finally, the expression patterns of 31 ESTs, putatively related to drought responses, were analyzed in a time-course experiment. Our results confirmed that such genes are more expressed in the tolerant genotype during stress; however, they are not exclusive, since different levels of these transcripts were also detected in the susceptible genotype. In addition, we observed a fluctuation in gene regulation over time for both the genotypes, which seem to adopt and adapt different strategies in order to develop tolerance against this stress.
Development of an Optical Gas Leak Sensor for Detecting Ethylene, Dimethyl Ether and Methane
Authors: Tan Qiulin , Pei Xiangdong , Zhu Simin , Sun Dong , Liu Jun , Xue Chenyang , Liang Ting , Zhang Wendong , Xiong Jijun
Published: March 2013

In this paper, we present an approach to develop an optical gas leak sensor that can be used to measure ethylene, dimethyl ether, and methane. The sensor is designed based on the principles of IR absorption spectrum detection, and comprises two crossed elliptical surfaces with a folded reflection-type optical path. We first analyze the optical path and the use of this structure to design a miniature gas sensor. The proposed sensor includes two detectors (one to acquire the reference signal and the other for the response signal), the light source, and the filter, all of which are integrated in a miniature gold-plated chamber. We also designed a signal detection device to extract the sensor signal and a microprocessor to calculate and control the entire process. The produced sensor prototype had an accuracy of ±0.05%. Experiments which simulate the transportation of hazardous chemicals demonstrated that the developed sensor exhibited a good dynamic response and adequately met technical requirements.
Rapid and Highly Sensitive Detection of Lead Ions in Drinking Water Based on a Strip Immunosensor
Authors: Kuang Hua , Xing Changrui , Hao Changlong , Liu Liqiang , Wang Libing , Xu Chuanlai
Published: March 2013

In this study, we have first developed a rapid and sensitive strip immunosensor based on two heterogeneously-sized gold nanoparticles (Au NPs) probes for the detection of trace lead ions in drinking water. The sensitivity was 4-fold higher than that of the conventional LFA under the optimized conditions. The visual limit of detection (LOD) of the amplified method for qualitative detection lead ions was 2 ng/mL and the LOD for semi-quantitative detection could go down to 0.19 ng/mL using a scanning reader. The method suffered from no interference from other metal ions and could be used to detect trace lead ions in drinking water without sample enrichment. The recovery of the test samples ranged from 96% to 103%. As the detection method could be accomplished within 15 min, this method could be used as a potential tool for preliminary monitoring of lead contamination in drinking water.
Optical Flow and Driver’s Kinematics Analysis for State of Alert Sensing
Authors: Jiménez-Pinto Javier , Torres-Torriti Miguel
Published: March 2013

Road accident statistics from different countries show that a significant number of accidents occur due to driver’s fatigue and lack of awareness to traffic conditions. In particular, about 60% of the accidents in which long haul truck and bus drivers are involved are attributed to drowsiness and fatigue. It is thus fundamental to improve non-invasive systems for sensing a driver’s state of alert. One of the main challenges to correctly resolve the state of alert is measuring the percentage of eyelid closure over time (PERCLOS), despite the driver’s head and body movements. In this paper, we propose a technique that involves optical flow and driver’s kinematics analysis to improve the robustness of the driver’s alert state measurement under pose changes using a single camera with near-infrared illumination. The proposed approach infers and keeps track of the driver’s pose in 3D space in order to ensure that eyes can be located correctly, even after periods of partial occlusion, for example, when the driver stares away from the camera. Our experiments show the effectiveness of the approach with a correct eyes detection rate of 99.41%, on average. The results obtained with the proposed approach in an experiment involving fifteen persons under different levels of sleep deprivation also confirm the discriminability of the fatigue levels. In addition to the measurement of fatigue and drowsiness, the pose tracking capability of the proposed approach has potential applications in distraction assessment and alerting of machine operators.
2-D Unitary ESPRIT-Like Direction-of-Arrival (DOA) Estimation for Coherent Signals with a Uniform Rectangular Array
Authors: Ren Shiwei , Ma Xiaochuan , Yan Shefeng , Hao Chengpeng
Published: March 2013

A unitary transformation-based algorithm is proposed for two-dimensional (2-D) direction-of-arrival (DOA) estimation of coherent signals. The problem is solved by reorganizing the covariance matrix into a block Hankel one for decorrelation first and then reconstructing a new matrix to facilitate the unitary transformation. By multiplying unitary matrices, eigenvalue decomposition and singular value decomposition are both transformed into real-valued, so that the computational complexity can be reduced significantly. In addition, a fast and computationally attractive realization of the 2-D unitary transformation is given by making a Kronecker product of the 1-D matrices. Compared with the existing 2-D algorithms, our scheme is more efficient in computation and less restrictive on the array geometry. The processing of the received data matrix before unitary transformation combines the estimation of signal parameters via rotational invariance techniques (ESPRIT)-Like method and the forward-backward averaging, which can decorrelate the impinging signalsmore thoroughly. Simulation results and computational order analysis are presented to verify the validity and effectiveness of the proposed algorithm.
Phylogenetic relationships of the mycoheterotrophic genus Voyria and the implications for the biogeographic history of Gentianaceae
Authors: Merckx Vincent S.F.T. , Kissling Jonathan , Hentrich Heiko , Janssens Steven B. , Mennes Constantijn B. , Specht Chelsea D. , Smets Erik F.
Published: March 2013

• Premise of the study: The angiosperm family Gentianaceae comprises over 1700 species in 91 genera. Gentianaceae are distributed worldwide, but most species occur in temperate zones. Phylogenetic studies demonstrate that the family consists of six monophyletic tribes. However, the phylogenetic position of the mycoheterotrophic genus Voyria, with a remarkable trans‐Atlantic distribution, remained unknown.

• Methods: We used nuclear ITS and 18S rDNA and mitochondrial apt1 and matR data to infer the phylogenetic position of Voyria in Gentianaceae. In addition, with Bayesian relaxed molecular clock analyses we obtained age estimates for the diversification of Voyria and Gentianaceae in general and used these results to reconstruct the ancestral areas associated with the early diversification events in Gentianaceae.

• Key results: Our results demonstrate that Voyria is an early diverging lineage within Gentianaceae with no close relationships to other mycoheterotrophic Gentianaceae lineages. Voyria originated in the neotropics during the Early Eocene but only reached its current transoceanic distribution around the end of the Oligocene. The neotropics were an important area for the early diversification events in Gentianaceae, most of which occurred during the Eocene.

• Conclusions: Voyria is an old, phylogenetically isolated lineage within Gentianaceae, and the current distribution of the genus is indicative of the ancestral area in which the early diversification events of Gentianaceae occurred. In parallel with many other pantropical families, our results suggest that migration of tropical taxa through Laurasia during the Early Eocene has played an important role in shaping the current global distribution of Gentianaceae.
Development and characterization of microsatellite markers for Alpinia oxyphylla (Zingiberaceae)
Authors: Zou Ying , Zou Pu , Liu Huanfang , Liao Jingping
Published: March 2013

• Premise of the study: Microsatellite loci were isolated and characterized for population genetic studies of Alpinia oxyphylla (Zingiberaceae), a perennial rhizomatous herbaceous plant often used medicinally in China.

• Methods and Results: A total of 85 loci were identified using a magnetic bead enrichment method, of which 23 were polymorphic. The level of polymorphism was characterized in 32 individuals from two populations; the number of alleles per locus ranged from 1 to 13; and observed heterozygosity and expected heterozygosity varied from 0 to 1 (mean: 0.6441) and 0 to 0.887 (mean: 0.6241), respectively.

• Conclusions: The polymorphic microsatellite markers generated from this study will be useful for genetic diversity and structure analysis of A. oxyphylla.
THE PROBLEM OF MODELLING A TRUNK AIR ROUTE NETWORK
Authors: Tseytlina Tatiana , Balashov Victor , Smirnov Andrey
Published: March 2013

In this work we developed a fuzzy neural network-based model of the conditions for the existence of air routes, i.e. the rules underlying the emergence, existence and elimination of air routes (direct links between cities). The model belongs to the class of information models: the existence or non-existence of an air route is considered dependent on a complex of parameters. These parameters characterise the transport link, as well as the generational and target capabilities of the connected cities. The model was constructed using genetic algorithm techniques and self-organising Kohonen maps (implemented by software features of the STATISTICA package), as well as software tools of the Fuzzy Logic Toolbox and the Neural Network Toolbox of the MatLab development environment. The model is used to forecast the development of the topology of the network. The forecast is a necessary component of long-term forecasts of demand in the aircraft market.
PSYCHOLOGICAL RESOURCES AIR FORCE PILOTS USE FOR SELF-REGULATION
Authors: Dolgova Olena , Ivaniuk Maryna , Tukayev Serhiy
Published: March 2013

This article contains the results of theoretical and empirical analysis of the psychological resources of air force pilots. It presents a model of psychological resources for self-regulation, the components of which are resilience, moral and ethical responsibility, flexibility, reflexivity, tolerance or intolerance for ambiguity, and mental health as a complex of personal resources such as autonomy, competency, personal growth, a positive attitude to others, life goals, and self-reliance.