bluuebunny/crossref_metadata_2025 huggingface dataset:
Ductile fiber wrapping for seismic retrofit of reinforced concrete columns
Authors: Choi Donguk , Vachirapanyakun S. , Kim S. -Y. , Ha S.-S.
Published: December 2015

An experimental study was performed on fiber wrapping to strengthen RC columns with insufficient moment capacity and ductility. In pseudo-seismic test of four columns with a circular cross section, the test variable was fiber type: none, carbon fiber (CF), polyethylene terephthalate (PET), and combined use of CF+PET. PET has high tensile strength and ductility, but very low elastic modulus. While a large area of PET typically needs to be used, the amount of PET actually utilized was about 50% of CF in terms of fiber axial stiffness (EfAf). All columns wrapped by CF and/or PET showed significantly improved strengths over the control column (121~143% of control column) while ductility also significantly improved (2.3~3.1 times the control column). Performance of PET was comparable to that of CF in terms of strength and ductility improvement while no sign of fiber rupture was observed at ultimate stage due to excellent ductility intrinsic with PET.
Effect of a small addition of highly expansive slag on volume stability of cement matrix material
Authors: Wang Wei Chien , Liu Chih Chien , Lee Chau
Published: December 2015

This study discussed firstly the mortar bar mix design proportion suitable for detecting the expansion behavior of furnace slag in cement matrix. Mortar bars were produced according to this mix proportion by replacing 1–9% of natural fine aggregate by highly expansive BOF (Basic Oxygen Furnace) slag. The mortar bar expansion amount was detected referring to the autoclaving procedure of ASTM C151 test. The effect of a small addition of highly expansive slag on the volume stability of cement matrix material was analyzed. The results showed that the mortar bar mix proportion suitable for detecting the expansion behavior of furnace slag in cement matrix was aggregate-cement volume ratio 3. The aggregate gradation met ASTM C227, and the standard flow water consumption was used. Replacing 1% of natural fine aggregate by BOF slag also caused apparent expansion of mortar bar in the autoclave expansion test. It was proved that a small amount of highly expansive slag in the cement matrix material has adverse effect on the volume stability. In addition, the furnace slag with expanding property must be stabilized before it is used as cement matrix aggregate.
Causality effect of capital market indicators on foreign investment model in Nigeria and South Africa (1980-2013)
Authors: Chi-Chi Ebiringa Onuorah Anastasia , Thaddeus Oforegbunam , Margaret Nnenna Okoli
Published: December 2015

This study examined causal effects of economic indicators attracting foreign investment inflows in Nigeria and South Africa. The purpose of the study is to investigate the behavioural pattern of economic indicators and determinants of economic indicators of capital market model influencing foreign investment inflows these two countries. The data were sourced from various economic and statistical bulletins of each country. Diagnostic test and Granger causality tests were the main econometric techniques for the analysis. The findings confirmed that for both countries; total value of transaction (TVT) and market capitalisation (MCAP) are the main economic indicators of capital market model (CMD) attracting foreign investment (FI). The study concluded that the identified economic indicators of CMD influenced FI in a short-run equilibrium relationship except interest rate having long-run equilibrium with foreign investment in South Africa. It is recommended that substantial approach and workable policy formulation and implementation in the stock exchange market to improve quality portfolio is highly needed to attract foreign investors in the global financial market.
A Canonical Analysis on the Relationship between Financial Risk Tolerance and Household Education Investment in Sri Lanka
Authors: Heenkenda Shirantha , Chandrakumara D.P.S
Published: December 2015

This paper is aimed at examining the relationship between risk tolerance behaviour and the education investment of families in different social sectors, i.e. urban, rural, and estate, in Sri Lanka. At the initial step, the study used Binary Logistic Regression for identifying the significant variables for financial risk tolerance and for household investment on education. Having identified the two sets of variables for each domain, the second step was to apply the Canonical Analysis in order to examine the association between risk tolerance behaviour and education investment. The data for the study was obtained from a sample survey conducted in six Divisional Secretariat Divisions (DSDs) of three districts in Sri Lanka. The sample was selected considering the social sectors as strata, using multi-stage sampling technique joined with cluster sampling. The study found that ‘social sector’ and ‘education of household head’ were the main contributors to ‘household investment on education’. It revealed that when the ‘social sector’ changes from urban to rural and rural to estate there is a tendency of households to decrease the share of expenditure on education. However, the ‘education level of the household head’ had s significant positive impact for the investment in education. It also found that ‘income quartile, decision maker’, ‘income diversification’, and ‘financial literacy’ positively contributed to ‘risk tolerance behaviour’. However, the findings show that financial risk tolerance decreases with the distance of households to a financial institute. The canonical relationship shows a negative association between ‘income quartile’ and the ‘social sector’ and the ‘income quartile’ improves with the change of the ‘social sector’ from estate to rural and rural to urban. It also revealed that ‘income quartile’ was positively associated with the ‘education of the household head’. A primary conclusion can be arrived at that income and spatial related attributes are crucial in determining the impact of risk tolerance in household education investment. In addition, the study revealed that risk tolerance and, in turn, the tendency to invest in education increases with the change of gender from female to male. Therefore, it suggests that gender related attributes are also important in the financial risk tolerance and education investment.
Árboles del Valle Central de Costa Rica: reproducción cortés negro Tabebuia impetiginosa (Mart. ex DC) Standl
Authors: Rojas-Rodríguez Freddy , Torres-Córdoba Gustavo
Published: December 2015

Se presenta una breve descripción del árbol cortés negro Tabebuia impetiginosa (Mart. ex DC) Standl, sobre fenología como base para la recolección de frutos, el manejo de las semillas, la viverización y el proceso de germinación.
Western water and climate change
Authors: Dettinger Michael , Udall Bradley , Georgakakos Aris
Published: December 2015

The western United States is a region long defined by water challenges. Climate change adds to those historical challenges, but does not, for the most part, introduce entirely new challenges; rather climate change is likely to stress water supplies and resources already in many cases stretched to, or beyond, natural limits. Projections are for continued and, likely, increased warming trends across the region, with a near certainty of continuing changes in seasonality of snowmelt and streamflows, and a strong potential for attendant increases in evaporative demands. Projections of future precipitation are less conclusive, although likely the northernmost West will see precipitation increases while the southernmost West sees declines. However, most of the region lies in a broad area where some climate models project precipitation increases while others project declines, so that only increases in precipitation uncertainties can be projected with any confidence. Changes in annual and seasonal hydrographs are likely to challenge water managers, users, and attempts to protect or restore environmental flows, even where annual volumes change little. Other impacts from climate change (e.g., floods and water‐quality changes) are poorly understood and will likely be location dependent.

In this context, four iconic river basins offer glimpses into specific challenges that climate change may bring to the West. The Colorado River is a system in which overuse and growing demands are projected to be even more challenging than climate‐change‐induced flow reductions. The Rio Grande offers the best example of how climate‐change‐induced flow declines might sink a major system into permanent drought. The Klamath is currently projected to face the more benign precipitation future, but fisheries and irrigation management may face dire straits due to warming air temperatures, rising irrigation demands, and warming waters in a basin already hobbled by tensions between endangered fisheries and agricultural demands. Finally, California's Bay‐Delta system is a remarkably localized and severe weakness at the heart of the region's trillion‐dollar economy. It is threatened by the full range of potential climate‐change impacts expected across the West, along with major vulnerabilities to increased flooding and rising sea levels.
Small Nations, Large Impact: The Caribbean Regional Midwives Association
Authors: Lewis Debrah , Rollock Marcia , Marshall Margaret , Carr Catherine , Fullerton Judith
Published: December 2015

This article presents an overview of the emergence of professional midwifery in the Caribbean region, beginning with colonial tradition, and linkages with nursing education and practice. Recent actions taken to strengthen the voice of midwifery as an autonomous profession are then described, including the vision for development of a Caribbean Regional Midwives Association (CRMA), which anticipates recognition as a new member status by the International Confederation of Midwives. CRMA members are engaged in efforts to build individual practitioner capacity in clinical practice and education, through shared activities and resources. CRMA members are also working toward regionalization of a midwifery core curriculum and common standards for regulation.
Humanized Childbirth and Cultural Humility: Designing an Online Course for Maternal Health Providers in Limited-Resource Settings
Authors: Sreenivas Amita , Cohen Susanna , Magaña-Valladares Laura , Walker Dilys
Published: December 2015

This article reviews the implications of disrespect and abuse in maternal health services, the growing movement to humanize childbirth and promote cultural humility, and one strategy to build an online course to address this issue among maternal health workers in Mexico. Reports of disrespect and abuse have been widely reported by women seeking health services, including maternity care, across the globe. Evidence indicates offenders are often health care professionals who do not consider their behavior inappropriate and believe they are acting in the interests of both mother and baby. These same providers are often overworked, underpaid, and have few role models who humanize childbirth and demonstrate cultural humility. Strategies which aim to foster competencies in humanized childbirth and cultural humility among health providers are lacking in current health professional training programs. Using the case of Mexico, the authors describe the template and justification for an online course for novice to expert health professionals to build competencies in humanized childbirth and cultural humility. Recommendations for future work are discussed.
Reinterpreting the Historicity of the Nordic Model
Authors: Kettunen Pauli
Published: December 2015

In conventional images of the so-called Nordic model, the strong state is opposed to markets or civil society and co-operation is opposed to conflict. These opposites appear problematic if one takes seriously the Nordic market- and interest-centered language used for the practices of social regulation, including the stubborn use of “labor market parties” instead of the EU concept “social partners”. Applying an approach sensitive to the historical and political aspects of language and concepts, the paper argues that a particular notion of social citizenship developed in the Nordic countries, in which interests rather than rights were put into the center. Such a notion of social citizenship was associated with two intertwined ideas, important in the development of the Nordic pattern of social reform: the idea of symmetry between workers and employers and the idea of a virtuous circle between divergent interests. With these ideas democracy and citizenship were combined with paid work and conflicting interests. This combination has been questioned by the projects for competitive national (and European) communities, responding to globalized and financialized capitalism. The vigorous comparisons of “models”, and the popularity of the concept of “the Nordic model”, can be seen as an aspect of this current transformation.
Gender Equality policy in Sweden: 1970s–2010s
Authors: Nyberg Anita
Published: December 2015

The aim of this article is to give an overview of gender equality policy in Sweden from the 1970s until today. A number of political measures and whether these measures individually, as well as combined, have promoted gender equality and the dual-earner/dual-carer model are described and analyzed. The conclusion is that the right to part-time work, publicly financed child care, parental leave, and tax deductions for domestic services make it easier for mothers to reconcile work and family, but do not challenge the distribution of family responsibilities between women and men. However, the individual right for fathers to 2 months of parental leave does challenge the gender order, to a certain extent, and fathers today participate more in care and domestic work than earlier. The dual-earner/dual-carer family is closer at hand when women have a higher education and earnings and thereby greater bargaining power. Employed work is more conditional among women with a lower education level, i.e., they may be employed but under the constraint that they are still responsible for care and domestic work in the family. Another constraint in this group where many work part-time is the lack of available full-time positions in the labor market.
Adsorption of crystal violet with diatomite earth&carbon by a modification of hydrothermal carbonization process
Authors: Yanzhuo Zhang , Jun Li , Guanghui Chen , Wei Bian , Yun Lu , Wenjing Li , Zhaoming Zheng , Xiaojie Cheng
Published: December 2015

The high colority and difficulty of decolorization are the most important tasks on printing and dyeing wastewater. This study investigates the ability of diatomite earth&carbon (DE&C) as an adsorbent to removal crystal violet (CV) from aqueous solutions. Fourier transform infrared spectroscopy results indicate the importance of functional groups during the adsorption of CV. The obtained N2 adsorption–desorption isotherm values accord with well IUPAC type II. Our calculations determined a surface area of 73.15 m2 g−1 for DE&C and an average pore diameter of 10.56 nm. Equilibrium data of the adsorption process fitted very well to the Langmuir model (R2 > 0.99). The results of kinetics study showed that the pseudo-second-order model fitted to the experimental data well. The thermodynamic parameters were also evaluated. ΔH° <0, ΔS° > 0 and ΔG° < 0 demonstrated that the adsorption process was spontaneous and exothermic for dye. Furthermore the positive value of ΔS° reflected good affinity of the CV dye.
A Cohesive Zone Model to Predict Dynamic Tearing of Rubber
Authors: Li Bo , Hoo Fatt Michelle S.
Published: December 2015

Tire failures, such as tread separation and sidewall zipper fracture, occur when internal flaws (cracks) nucleate and grow to a critical size as result of fatigue or cyclic loading. Sudden and catastrophic rupture takes place at this critical crack size because the strain energy release rate exceeds the tear energy of the rubber in the tire. The above-mentioned tire failures can lead to loss of vehicle stability and control, and it is important to develop predictive models and computational tools that address this problem. The objective of this article was to develop a cohesive zone model for rubber to numerically predict crack growth in a rubber component under dynamic tearing. The cohesive zone model for rubber was embedded into the material constitutive equation via a user-defined material subroutine (VUMAT) of ABAQUS. It consisted of three parts: (1) hyperviscoelastic behavior before damage, (2) damage initiation based on the critical strain energy density, and (3) hyperviscoelastic behavior after damage initiation. Crack growth in the tensile strip and pure shear specimens was simulated in ABAQUS Explicit, and good agreement was reported between finite element analysis predictions and test results.
A Rare and Emerging Entity: Sinonasal IgG4–related Sclerosing Disease
Authors: Song Brian H. , Baiyee Daniel , Liang Jonathan
Published: December 2015

Background

Immunoglobulin G4 (IgG4) related sclerosing disease (rSD) is a new disease entity, first described in 2001, that involves autoimmune pancreatitis. Considered a systemic disease with lesions described in multiple organ systems, IgG4-rSD that affects the sinonasal region is rare. Our goal was to highlight the sinonasal presentation of this unique disease and to review previously reported adult cases from 2003 to 2014.

Methods

Case report (a 72-year-old man who presented with left exophthalmos, periorbital pain, and epiphora) and review of the literature.

Results

Radiographic workup with computed tomography and magnetic resonance imaging demonstrated a left sinonasal mass that involved the left maxillary and ethmoid sinuses, with surrounding bony destruction and orbital invasion. Nasal endoscopy demonstrated a fibrous lesion emanating in the middle meatus, with surrounding mucosal inflammation. The patient underwent an endoscopic biopsy, medial maxillectomy, and ethmoidectomy with tumor debulking. Pathology demonstrated inflamed respiratory mucosa with dense lymphoplasmacytic infiltrate and fibrosis; flow cytometry demonstrated no malignant cell populations; immunophenotyping demonstrated multiple foci of IgG4 cells. Plasma IgG4 was elevated in the setting of normal total IgG. The patient was treated with postoperative systemic and topical corticosteroids. Surveillance imaging studies and nasal endoscopy demonstrated disease resolution without recurrence.

Conclusions

Sinonasal IgG4-rSD is a rare disease that can present with bony and soft-tissue invasion. This was an exceptional case, with osseous involvement and orbital invasion. Immunohistologic workup is essential for diagnosis. It is important to differentiate this disease from sinonasal tumors. Treatment includes corticosteroids and surgical debulking. Sinonasal IgG4-rSD represents an emerging disease that may present challenges for future rhinologists.
Depletion of Gadolinium burnable poison in a PWR assembly with high burnup fuel
Authors: Refeat R. M.
Published: December 2015

A tendency to increase the discharge burnup of nuclear fuel for Advanced Pressurized Water Reactors (PWR) has been a characteristic of its operation for many years. It will be able to burn at very high burnup of about 70 GWd/t with UO2 fuels. The U-235 enrichment must be higher than 5 %, which leads to the necessity of using an extremely efficient burnable poison like Gadolinium oxide. Using gadolinium isotope is significant due to its particular depletion behavior (“Onion-Skin” effect). In this paper, the MCNPX2.7 code is used to calculate the important neutronic parameters of the next generation fuels of PWR. K-infinity, local peaking factor and fission rate distributions are calculated for a PWR assembly which burn at very high burnup reaching 70 GWd/t. The calculations are performed using the recently released evaluated Gadolinium cross section data. The results obtained are close to those of a LWR next generation fuel benchmark problem. This demonstrates that the calculation scheme used is able to accurately model a PWR assembly that operates at high burnup values.
Thermal hydraulic analysis of reactivity accidents in MTR research reactors using RELAP5
Authors: El-Sahlamy N. , Khedr A. , D’Auria F.
Published: December 2015

The present paper comes in the line with the international approach which use the best estimate codes, instead of conservative codes, to get more realistic prediction of system behavior under off-normal reactor conditions. The aim of the current work is to apply this approach using the thermal-hydraulic system code RELAP5/Mod3.3 in a reassessment of safety of the IAEA benchmark 10 MW Research Reactor. The assessment is performed for both slow and fast reactivity insertion transients at initial power of 1.0 W. The reactor power is calculated using the RELA5 point kinetic model. The reactivity feedback terms are considered in two steps. In the first step the feedback from changes in water density and fuel temperature (Doppler effects) are considered. In the second step the feedback from the water temperature changes is added. The results from the first step are compared with that published in IAEA-TECDOC-643 benchmarks. The comparison shows that RELAP5 over predicts the peak power and consequently the fuel, clad and coolant temperatures in case of fast reactivity insertion. The results from the second step show unjustified values for reactor power. Therefore, the model of reactivity feedback from water temperature changes in the RELAP5 code may have to be reviewed.
Interlaboratory Study and Precision Statement for AASHTO T 336 Test Method
Authors: Gudimettla Jagan M. , Crawford Gary L. , Tanesi Jussara , Ardani Ahmad A.
Published: December 2015

With the recent release of AASHTOWare Pavement ME Design software, there will be a greater emphasis on measuring the coefficient of thermal expansion (CTE) of concrete because of its significance on predicted distress and design life. The most widely used test method to measure the CTE of concrete is the AASHTO T 336 test method. Data are presented from an interlaboratory (round robin) study conducted by FHWA; this study included 20 CTE units and laboratories representing FHWA, state highway agencies, universities, commercial testing laboratories, and the concrete paving industry. As part of the study, each laboratory tested nine concrete specimens (three concrete mixtures 3 three specimens per mixture) that spanned the typical range of CTE values for concrete. On the basis of this interlaboratory study for the AASHTO T 336 test method, the within-laboratory single operator standard deviation was found to be 0.12 mstrain/°C and the between-laboratory standard deviation was found to be 0.28 mstrain/°C. Data from the study also showed that there was no statistically significant difference between custom-built CTE devices versus commercially available testing devices. This demonstrates the ruggedness of the current test method.
Assessing Performance of Glow-in-the-Dark Concrete
Authors: Wiese Andrew , Washington Taylor , Tao Bernard , Weiss W. Jason
Published: December 2015

The objective of this research was to develop a soy-based luminescent sealant for use on concrete surfaces. The luminescent sealant was a mixture of soy methyl ester polystyrene and strontium aluminate, a phosphorescent powder that slowly luminesces after being excited by light. A test procedure was developed to quantify the magnitude and duration of the luminance of the coated concrete surface; quantifying the luminance was key in evaluating the performance of the luminescent sealant. The luminescent sealant was excited in a consistent manner with a xenon lighting system that simulated sunlight, a photometer (light-measuring instrument) that measured the luminance of the excited concrete surface, and a housing unit that prevented extraneous light from the surroundings from influencing the test results. Results of the tests indicated that the luminescent surface emitted light (i.e., glowed) for approximately 24 h in a dark space after it was excited. Larger particles of strontium aluminate were found to luminesce for a longer time than did smaller particles. The excited sealant's luminance was independent of the amount of time it was exposed to light coming from the xenon lighting system.
Laboratory Fatigue and Toughness Evaluation of Fiber-Reinforced Concrete
Authors: Mulheron Matthew , Kevern John T. , Rupnow Tyson D.
Published: December 2015

Concrete pavement design is currently centered on steel reinforcement: whether in the form of dowel bars, as in jointed plain concrete pavement, or in the form of continuous rebar reinforcement, as in continuously reinforced concrete pavement. The use of steel in concrete pavements presents durability problems because of the corrodibility of steel. This study evaluated the use of polypropylene fibrillated fibers, polypropylene macrofibers, and carbon fibers as primary reinforcement in concrete pavements for the Louisiana Department of Transportation and Development. Results showed that fiber reinforcement can be used to improve both the fatigue and toughness performance of concrete. When post-cracked strength or toughness was the concern, concrete containing more fibers and fibers with a high tensile strength was desirable. Carbon fibers maintained greater load-carrying capacity at lower deflections than did the steel fibers, which produced the greatest ductility. However, toughness and fatigue performance did not correlate for small deflections; this result suggests that polypropylene macrofibers may be adequate for repeated, low-stress loading. This study also found that when repeated low deflections were a concern, such as with pavements, there had to be sufficient fibers across a crack to maintain a tight crack. Conversely, too many fibers prevented adequate consolidation and aggregate interlock and negatively influenced performance. The resultant pavement design, continuously fiber-reinforced concrete pavement, will provide an alternative to jointed plain concrete pavement and continuously reinforced concrete pavement in highway pavement design that is not susceptible to durability problems associated with corrosion of reinforcement.
Pavement Concrete with Air-Cooled Blast Furnace Slag and Dolomite as Coarse Aggregates
Authors: Verian Kho Pin , Panchmatia Parth , Olek Jan , Nantung Tommy
Published: December 2015

This study evaluated the effects of substituting natural coarse aggregate (dolomite) with air-cooled blast furnace slag (ACBFS) on the strength and durability properties of pavement concretes. The scope of the study included evaluation and analysis of four types of concrete subjected to three deicers [calcium chloride (CaCl2), magnesium chloride (MgCl2), and sodium chloride (NaCl)] while undergoing freeze–thaw (FT) exposure. Of the four types of concrete mixtures, two were prepared with ACBFS and two with natural dolomite as coarse aggregate. For each aggregate type, one mixture was produced with Type 1 portland cement, while the second one was produced with a binder composed of Type 1 cement and Class C fly ash (20% replacement by weight). Fresh properties of concrete tested included slump, unit weight, and total air content, while compressive and flexural strengths were measured for hardened concrete. Durability of concrete exposed to FT was assessed by periodically measuring dynamic modulus of elasticity of concrete and average depth of chloride penetration. Concrete with ACBFS aggregates developed slightly higher (~6%) compressive strength but lower (~15%) flexural strength than did concrete with natural dolomite. Periodic measurements of dynamic modulus of elasticity and visual observations of test specimens showed that of the three deicers used, the CaCl2 was the most aggressive, followed by MgCl2 and NaCl. In regard to resistance to the FT cycles in the presence of deicers, fly ash concretes (with either ACBFS or dolomite as coarse aggregate) showed better performance than did corresponding plain cement concretes.
Effect of Sand Content on Properties of Self-Consolidating, High-Performance Cementitious Mortar
Authors: Li Zhengqi , Rangaraju Prasada Rao
Published: December 2015

The workability and compressive strength of a high-performance cementitious mortar (HPCM) produced by using a natural siliceous sand were studied as a function of sand content [expressed as sand-to-cementitious materials ratio (s/cm)], silica fume (SF) content, and high-range water reducing admixture (HRWRA) dosage. The purpose of this study was to maximize the proportion of sand content without negatively affecting workability and mechanical and durability properties when these characteristics were achieved at a low cost. Test results indicated that the workability of HPCM became less sensitive to sand content when the SF content increased. Statistical analysis showed that the compressive strength of self-consolidating HPCM was not significantly affected by sand content up to a certain maximum level, which was dependent on the HRWRA and SF dosage. On the basis of combined consideration of both workability and compressive strength, the maximum s/cm ratio to produce a self-consolidating HPCM with SF content at 0%, 10%, and 20% was 1.6, 1.6, and 2.0, respectively. Also, increasing the sand content was helpful in improving the durability of HPCM, because chloride ion permeability and drying shrinkage decreased.
Accelerated Slab Replacement Using Self-Consolidating Concrete
Authors: Armaghani Jamshid , Tawfiq Kamal , Squillacote Steven , Bergin Michael
Published: December 2015

A self-consolidating concrete (SCC) mix was developed to accelerate the construction of replacement slabs in concrete pavement rehabilitation projects. This work was part of a larger research project to develop an innovative process involving the use of temporary and reusable precast slabs and an SCC mix for construction of replacement slabs to reduce construction time and increase contractor production in concrete pavement rehabilitation projects. Two requirements were set for the SCC mix, high workability and flow rate without segregation, and a minimum 6-h compressive strength of 2,200 pounds per square inch [psi (15 MPa)] required by the Florida Department of Transportation (DOT). The SCC mix incorporated Grade 57 aggregate as well as a combination of admixtures, including a high range water reducer, workability retainer, water reducer and set retarder, and accelerator. Laboratory trial batches were prepared for the proposed mix and tested for workability and strength. On the basis of test results of the trial batches, the refined SCC mix was developed to achieve the high workability needed for faster concrete discharge and finish and to attain the Florida DOT's 6-h strength requirement of 2,200 psi (15 MPa) for slab replacements.
Accident Prediction Models for Bus Rapid Transit Systems
Authors: Gómez Fidel , Bocarejo Juan Pablo
Published: December 2015

This research sought to model traffic accidents in the bus rapid transit (BRT) system in Bogotá, Colombia. For each BRT station, 35 variables related to system flows, infrastructure, service, surroundings, and socio-economic context were tested. After a selection process, a set of 11 explanatory variables was obtained and used in the development of generalized linear models (Poisson and negative binomial models) and a neural network model. The results showed that the neural network model had better predictability indicators than did those obtained by the Poisson and negative binomial models. Additionally, the negative binomial regression model did not produce better predictions than did the Poisson regression model. Finally, a scenario analysis was developed from the most relevant variables: bus flow, number of accesses, and proximity to at-grade vehicular intersections.
Traffic Safety Evaluation of Uncontrolled Intersections using Surrogate Safety Measures under Mixed Traffic Conditions
Authors: Vedagiri P. , Killi Deepak V.
Published: December 2015

In the developing world, with increases in population, the number of vehicles is increasing tremendously. Traffic safety on roads has become a major concern even with advancements in technology and infrastructure. Traffic safety assessments and accident prediction based on accident data is a reactive approach. There are known drawbacks related to the reliability of accident data, especially in developing countries with large populations, such as India. It is, however, unethical to wait for accidents to occur before drawing statistically accurate conclusions regarding safety impacts. To overcome this impediment, one needs to develop accurate models that rely on surrogate safety measures (SSMs) for effective safety evaluations. The main advantage associated with the use of these models is that they can model crashes more frequently than in the real world and thereby imply an efficient and more statistically reliable proximal measure of traffic safety. The objective of this study is to examine the impact of management measures on traffic safety at a three-arm uncontrolled intersection with the use of microsimulation modeling under mixed traffic conditions. This examination was done by developing a unique methodology of measuring one SSM, postencroachment time (PET). This paper describes improvement in the accuracy of crash predictions by proposing a methodology to calculate PET.
Numerical Simulation of Laminar Forced Convection of Pin-Fin Heat-Sink Array in a Channel by Using Porous Approach
Authors: Jeng Tzer-Ming , Tzeng Sheng-Chung
Published: December 2015

This work used a porous approach model to numerically investigate the fluid flow and heat transfer characteristics of the pin-fin heat-sink array in a rectangular channel with in-line arrangement. The air flow through the channel was laminar. The pin-fin heat sinks with various porosities and pin-fin numbers were employed. The relative center-to-center longitudinal and transverse distances between adjacent heat sinks were changed. The results indicate that the Nusselt number of various heat-sink arrays increased with decreasing the relative center-to-center transverse distance, but not varied with the relative center-to-center longitudinal distance. For the typical pin-fin heat-sink arrays, the Nusselt number changed slightly for the heat sinks with 0.358–0.556 porosity, but increased by 11.7%–24.8% when the porosity increased from 0.556 to 0.750, and then dropped obviously when the porosity exceeded 0.750. Increasing the number of pin fins continuously could increase Nusselt number. However, when the number of pin fins was large, the Nusselt number increased with the number of pin fins slowly. The present numerical simulation has been validated by the typical experiment. Finally, a semi-empirical correlation of Nusselt number for each heat sink in the heat-sink array was proposed.
Zeolite Membranes in Catalysis—From Separate Units to Particle Coatings
Authors: Dragomirova Radostina , Wohlrab Sebastian
Published: December 2015

Literature on zeolite membranes in catalytic reactions is reviewed and categorized according to membrane location. From this perspective, the classification is as follows: (i) membranes spatially decoupled from the reaction zone; (ii) packed bed membrane reactors; (iii) catalytic membrane reactors and (iv) zeolite capsuled catalyst particles. Each of the resulting four chapters is subdivided by the kind of reactions performed. Over the whole sum of references, the advantage of zeolite membranes in catalytic reactions in terms of conversion, selectivity or yield is evident. Furthermore, zeolite membrane preparation, separation principles as well as basic considerations on membrane reactors are discussed.
High-Throughput Screening of Heterogeneous Catalysts for the Conversion of Furfural to Bio-Based Fuel Components
Authors: Pizzi Roberto , Van Putten Robert-Jan , Brust Hanneke , Perathoner Siglinda , Centi Gabriele , Van der Waal Jan
Published: December 2015

The one-pot catalytic reductive etherification of furfural to 2-methoxymethylfuran (furfuryl methyl ether, FME), a valuable bio-based chemical or fuel, is reported. A large number of commercially available hydrogenation heterogeneous catalysts based on nickel, copper, cobalt, iridium, palladium and platinum catalysts on various support were evaluated by a high-throughput screening approach. The reaction was carried out in liquid phase with a 10% w/w furfural in methanol solution at 50 bar of hydrogen. Among all the samples tested, carbon-supported noble metal catalysts were found to be the most promising in terms of productivity and selectivity. In particular, palladium on charcoal catalysts show high selectivity (up to 77%) to FME. Significant amounts of furfuryl alcohol (FA) and 2-methylfuran (2-MF) are observed as the major by-products.
Heterogeneous Ru-Based Catalysts for One-Pot Synthesis of Primary Amines from Aldehydes and Ammonia
Authors: Dong Bo , Guo Xingcui , Zhang Bo , Chen Xiufang , Guan Jing , Qi Yunfei , Han Sheng , Mu Xindong
Published: December 2015

The direct reductive amination of carbonyl compounds with NH3 and H2 is an alternative route to produce primary amines in practical production. The search for efficient and selective catalysts has attracted great interest. In the present work, the reductive amination of heptaldehyde with NH3 was investigated over a Ru-based catalyst. The product selectivities were found to be related with the supports of Ru. The alumina with spinel structure (γ-Al2O3, θ-Al2O3)-supported Ru catalysts exhibited selectivity favoring primary amines (94% yield) at 100% heptaldehyde conversion under optimal conditions. Purely basic (MgO, CaO) and relative acidic (Nb2O5, SnO2, MCM-41, HZSM-5) supports showed relatively poor selectivity towards primary amines (0%–53% yield). The reductive amination mechanism was also proposed. The Schiff base N-[heptylene]heptyl-1-amine was a key intermediate. Ru/γ-Al2O3 was shown to be an excellent hydrogenolysis catalyst to selectively produce primary amine by amination and hydrogenolysis of N-[heptylene]heptyl-1-amine.
Optimization of Biodiesel-Diesel Blended Fuel Properties and Engine Performance with Ether Additive Using Statistical Analysis and Response Surface Methods
Authors: Ali Obed , Mamat Rizalman , Najafi Gholamhassan , Yusaf Talal , Safieddin Ardebili Seyed
Published: December 2015

In this study, the fuel properties and engine performance of blended palm biodiesel-diesel using diethyl ether as additive have been investigated. The properties of B30 blended palm biodiesel-diesel fuel were measured and analyzed statistically with the addition of 2%, 4%, 6% and 8% (by volume) diethyl ether additive. The engine tests were conducted at increasing engine speeds from 1500 rpm to 3500 rpm and under constant load. Optimization of independent variables was performed using the desirability approach of the response surface methodology (RSM) with the goal of minimizing emissions and maximizing performance parameters. The experiments were designed using a statistical tool known as design of experiments (DoE) based on RSM.
Waste-to-Energy in China: Key Challenges and Opportunities
Authors: Zhang Dongliang , Huang Guangqing , Xu Yimin , Gong Qinghua
Published: December 2015

China—the largest developing country in the world—is experiencing both rapid economic maturation and large-scale urbanization. These situations have led to waste disposal problems, and the need to identify alternative energy sources. Waste-to-energy (WTE) conversion processes, a source of renewable energy, are expected to play an increasingly important role in China’s sustainable management of municipal solid waste (MSW). The purpose of this research is to investigate the key problems and opportunities associated with WTE, to provide recommendations for the government. This paper begins by describing China’s current MSW management situation and analyzing its waste disposal problems. The major challenges associated with China’s WTE incineration are then discussed from economic, environmental and social points of view. These include the high costs associated with constructing necessary facilities, the susceptibility of facilities to corrosion, the lower heating value of China’s MSW, air pollutant emissions and especially public opposition to WTE incineration. Since discarded waste can be used to produce energy for electricity and heat—thus reducing its volume and the production of greenhouse gas (GHG) emissions—with government policies and financial incentives, the use of WTE incineration as a renewable energy source and part of a sustainable waste management strategy will be of increasing importance in the future. The paper concludes by summarizing the management, economic and social benefits that could be derived from developing the country’s domestic capacity for producing the needed incineration equipment, improving source separation capabilities, standardizing regulatory and legal responsibilities and undertaking more effective public consultation processes.
Histone H2AX Is Involved in FoxO3a-Mediated Transcriptional Responses to Ionizing Radiation to Maintain Genome Stability
Authors: Tarrade Stephane , Bhardwaj Tanya , Flegal Matthew , Bertrand Lindsey , Velegzhaninov Ilya , Moskalev Alexey , Klokov Dmitry
Published: December 2015

Histone H2AX plays a crucial role in molecular and cellular responses to DNA damage and in the maintenance of genome stability. It is downstream of ataxia telangiectasia mutated (ATM) damage signaling pathway and there is an emerging role of the transcription factor FoxO3a, a regulator of a variety of other pathways, in activating this signaling. We asked whether H2AX may feedback to FoxO3a to affect respective FoxO3a-dependent pathways. We used a genetically matched pair of mouse embryonic fibroblast H2AX+/+ and H2AX−/− cell lines to carry out comprehensive time-course and dose-response experiments and to show that the expression of several FoxO3a-regulated genes was altered in H2AX−/− compared to H2AX+/+ cells at both basal and irradiated conditions. Hspa1b and Gadd45a were down-regulated four- to five-fold and Ddit3, Cdkn1a and Sod2 were up-regulated 2–3-fold in H2AX−/− cells. Using the luciferase reporter assay, we directly demonstrated that transcriptional activity of FoxoO3a was reduced in H2AX−/− cells. FoxO3a localization within the nuclear phospho-ATM (Ser1981) foci in irradiated cells was affected by the H2AX status, as well as its posttranslational modification (phospho-Thr32). These differences were associated with genomic instability and radiosensitivity in H2AX−/− cells. Finally, knockdown of H2AX in H2AX+/+ cells resulted in FoxO3a-dependent gene expression patterns and increased radiosensitivity that partially mimicked those found in H2AX−/− cells. Taken together, our data suggest a role for FoxO3a in the maintenance of genome integrity in response to DNA damage that is mediated by H2AX via yet unknown mechanisms.
Luteinizing Hormone Releasing Hormone/Galactose Core/Lipopeptide
Authors: Simerska Pavla , Lai Hoi , Toth Istvan
Published: December 2015

A self-adjuvanting vaccine candidate comprising four copies of luteinizing hormone releasing hormone (LHRH), a galactose carrier/core and lipoamino acid based adjuvant was synthesized in 21% yield by a solid phase peptide synthesis, carbohydrate and Boc-chemistry methods.
Improvement of Bearing Capacity in Recycled Aggregates Suitable for Use as Unbound Road Sub-Base
Authors: Garach Laura , López Mónica , Agrela Francisco , Ordóñez Javier , Alegre Javier , Moya José
Published: December 2015

Recycled concrete aggregates and mixed recycled aggregates are specified as types of aggregates with lower densities, higher water absorption capacities, and lower mechanical strength than natural aggregates. In this paper, the mechanical behaviour and microstructural properties of natural aggregates, recycled concrete aggregates and mixed recycled aggregates were compared. Different specimens of unbound recycled mixtures demonstrated increased resistance properties. The formation of new cement hydrated particles was observed, and pozzolanic reactions were discovered by electronon microscopy in these novel materials. The properties of recycled concrete aggregates and mixed recycled aggregates suggest that these recycled materials can be used in unbound road layers to improve their mechanical behaviour in the long term.
Nanoscience Supporting the Research on the Negative Electrodes of Li-Ion Batteries
Authors: Mauger Alain , Julien Christian
Published: December 2015

Many efforts are currently made to increase the limited capacity of Li-ion batteries using carbonaceous anodes. The way to reach this goal is to move to nano-structured material because the larger surface to volume ratio of particles and the reduction of the electron and Li path length implies a larger specific capacity. Additionally, nano-particles can accommodate such a dilatation/contraction during cycling, resulting in a calendar life compatible with a commercial use. In this review attention is focused on carbon, silicon, and Li4Ti5O12 materials, because they are the most promising for applications.
Nutrient Status Assessment in Individuals and Populations for Healthy Aging—Statement from an Expert Workshop
Authors: Péter Szabolcs , Saris Wim , Mathers John , Feskens Edith , Schols Annemie , Navis Gerjan , Kuipers Folkert , Weber Peter , Eggersdorfer Manfred
Published: December 2015

A workshop organized by the University Medical Center Groningen addressed various current issues regarding nutrient status of individuals and populations, tools and strategies for its assessment, and opportunities to intervene. The importance of nutrient deficiencies and information on nutrient status for health has been illustrated, in particular for elderly and specific patient groups. The nutrient profile of individuals can be connected to phenotypes, like hypertension or obesity, as well as to socio-economic data. This approach provides information on the relationship between nutrition (nutrient intake and status) and health outcomes and, for instance, allows us to use the findings to communicate and advocate a healthy lifestyle. Nutrition is complex: a broader profile of nutrients should be considered rather than focusing solely on a single nutrient. Evaluating food patterns instead of intake of individual nutrients provides better insight into relationships between nutrition and health and disease. This approach would allow us to provide feedback to individuals about their status and ways to improve their nutritional habits. In addition, it would provide tools for scientists and health authorities to update and develop public health recommendations.
P40 and P90 from Mpn142 are Targets of Multiple Processing Events on the Surface of Mycoplasma pneumoniae
Authors: Widjaja Michael , Berry Iain , Pont Elsa , Padula Matthew , Djordjevic Steven
Published: December 2015

Mycoplasma pneumoniae is a significant cause of community acquired pneumonia globally. Despite having a genome less than 1 Mb in size, M. pneumoniae presents a structurally sophisticated attachment organelle that (i) provides cell polarity, (ii) directs adherence to receptors presented on respiratory epithelium, and (iii) plays a major role in cell motility. The major adhesins, P1 (Mpn141) and P30 (Mpn453), are localised to the tip of the attachment organelle by the surface accessible cleavage fragments P90 and P40 derived from Mpn142. Two events play a defining role in the formation of P90 and P40; removal of a leader peptide at position 26 (23SLA↓NTY28) during secretion to the cell surface and cleavage at amino acid 455 (452GPL↓RAG457) generating P40 and P90. Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) analysis of tryptic peptides generated by digesting size-fractionated cell lysates of M. pneumoniae identified 15 cleavage fragments of Mpn142 ranging in mass from 9–84 kDa. Further evidence for the existence of cleavage fragments of Mpn142 was generated by mapping tryptic peptides to proteins recovered from size fractionated eluents from affinity columns loaded with heparin, fibronectin, fetuin, actin, plasminogen and A549 surface proteins as bait. To define the sites of cleavage in Mpn142, neo-N-termini in cell lysates of M. pneumoniae were dimethyl-labelled and characterised by LC-MS/MS. Our data suggests that Mpn142 is cleaved to generate adhesins that are auxiliary to P1 and P30.