bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and characterization of poly(trimethylene terephthalate)/organoclay nanocomposite via in situ polymerization
Authors: Sheikholeslami Sogol Naghavi , Rafizadeh Mehdi , Taromi Framarz Afshar , Bouhendi Hossein
Published: February 2013

Neat poly(trimethylene terephthalate) (PTT) and PTT/modified organoclay nanocomposite with various amounts of clay were synthesized by a two-step procedure. Terephthalic acid (TPA) was reacted with 1,3-propanediol (1,3-PDO) in the esterification step. Then, polycondensation reaction resulted in the formation of PTT in the presence of tetra buthyl titanate (Ti(OC4H9)4) as a catalyst. Commercially available organoclay (Cloisite 30B) was modified using 3-aminopropyltriethoxysilane via a silylation reaction. Thermal stability of modified clay was studied by means of thermal gravimetric analysis (TGA) that showed 10% less weight loss than Cloisite 30B. PTT/organoclay nanocomposites with 0.5, 1 and 2 wt% of modified organoclay were prepared by in situ polymerization. Synthesized polyesters were characterized by Fourier-transform infrared spectroscopy and proton-nuclear magnetic resonance spectroscopy (1H-NMR). Number average molecular weights were determined by 1H-NMR and a new Mark–Houwink equation is reported for highly pure dichloroacetic acid as solvent at 25°C. Polymer’s morphology was examined with x-ray diffraction and transmission electron microscopy. It was observed that clay layers were not accumulated. Thermal properties and crystallization behavior were investigated by differential scanning calorimetry and TGA. Crystallization temperature ( Tc) of nanocomposites increased about 6°C compared to neat PTT that reflects greater overall crystallization. Modified Averami Equation was used to describe crystallization kinetics and crystal size was studied using polarized optical microscopy. It was observed that crystal size reduces with nanoclay content. PTT mostly is used as polymeric fiber. Hence, dyeability of neat PTT and nanocomposites was investigated using a spectrophotometer. About 32% increase in color uptake was determined.
Constituting balance between strength and toughness in nanocomposites based on PP/SEBS-g-MA blends
Authors: Ranjbar Mostafa , Arefazar Ahmad , Bakhshandeh Gholamreza
Published: February 2013

In this article, polypropylene/styrene–ethylene–butylene–styrene grafted with maleic anhydride (PP/SEBS- g-MA) triblock copolymer blends and their samples containing various amounts of organo-modified montmorillonite (1–5 phr) are prepared through melt compounding in an internal mixer. X-Ray diffraction (XRD) and transmission electron microscopy (TEM) are used to evaluate the dispersion of nanoclay particles in the blends. The measurements of mechanical and thermal properties of all the samples are carried out by means of standard methods. XRD and TEM results show existence of exfoliated and intercalated structures in the samples. Furthermore, the measurements of mechanical properties of the samples show that despite the decrease in tensile strength and Young’s modulus of PP in the presence of SEBS- g-MA as a toughening agent, addition of clay as the reinforcing filler improves these properties. So, a good balance between strength/stiffness and toughness/ductility is obtained with the addition of SEBS- g-MA and clay simultaneously and controlling their contents. Finally, thermal studies reveal that addition of clay has no significant influence on the structure and stability of the PP crystals formed.
Effect of woven flax structures on morphology and properties of reinforced modified polylactide composites
Authors: Siengchin Suchart , Dangtungee Rapeephun
Published: February 2013

Composites composed of polylactide (PLA), modified PLA and woven flax fiber textiles (flax weave style of 2 × 2 twill and 4 × 4 hopsack) were produced by hot press technique. Two structurally different additives were used to modify PLA. The dispersion of the flax in the composites was studied by scanning electron microscopy and computed microtomography system (µCT). The PLA composites were subjected to water absorption and instrumented falling weight impact tests. The thermomechanical and creep properties of the composites were determined using thermogravimetric analysis, dynamic-mechanical thermal analysis and short-time creep tests. It was found that the modified PLA and its composite increased the impact resistance compared with the unmodified PLA. Incorporation of flax decreased resistance to thermal degradation and increased water uptake. The impact energy and stiffness value of PLA/flax composites were markedly higher than that of PLA but reflect the effects of composite structures and flax content. The storage modulus master curves were constructed by applying the time–temperature superposition principle. From the master curve data, the effect of modified PLA on the storage modulus was more pronounced in the low frequency range.
Studies on the effect of maleic anhydride–grafted polypropylene with different MFI on mechanical, thermal and morphological properties of fly ash-filled PP composites
Authors: Kulkarni MB , Mahanwar PA
Published: February 2013

Present study deals with the effect of variation in melt flow index (MFI) of maleic anhydride–grafted polypropylene (PP- g-MAH) as a polymeric compatibilizing agent on various properties of fly ash (FA)-filled polypropylene (PP) composites. The FA content was varied from 0 to 40 wt%. The effect of polymeric compatibilizing agents with different MFI and very high maleic anhydride (MAH) content on interfacial adhesion between filler and matrix and filler dispersion were studied. The mechanical and thermal properties of the composite material were evaluated, and the microstructure was investigated through scanning electron microscopy. The values of yield stress and breaking strength of compatibilized PP/PP- g-MAH/FA-based composites showed higher values compared to that of untreated FA-filled PP composites at corresponding filler content. Incorporation of FA into PP led to stiffer materials, as tensile modulus increased significantly. Tensile and impact properties varied with varying molecular weight of PP in PP- g-MAH and are essentially decided by wettability of the filler. It is also found that heat-deflection temperature and vicat softening point improved with the addition of FA filler. The use of PP- g-MAH as polymeric coupling agent provides improvement in mechanical and thermal properties of filled polymers. The higher effect of compatibilization is obtained using high-molecular-weight PP in PP- g-MAH as a polymeric compatibilizing agent and low-molecular-weight PP in PP- g-MAH resulted in better dispersion of FA in PP matrix. The overall results showed that FA dispersion and interfacial adhesion are greatly affected by the kind of PP- g-MAH.
Effect of nano-calcium carbonate content on the properties of poly(urethane methacrylate) nanocomposites
Authors: Maurya Shyam Dev , Purushothaman M , Krishnan P Santhana Gopala , Nayak Sanjay K
Published: February 2013

Nanocomposites containing nano-calcium carbonate (nano-CaCO3) in the range of 0.25–1.5% (w/w) were prepared via in situ polymerization of urethane methacrylate pre-polymer derived from poly(ethylene glycol) (PEG 400), polymeric diphenylmethane diisocyanate and 2-hydroxyethyl methacrylate. Incorporation of nano-CaCO3 into poly (urethane methacrylate) matrix was confirmed by Fourier transform infrared spectroscopy and wide-angle x-ray diffraction studies. Density studies indicated that nanocomposites containing 0.75 wt% nano-CaCO3 had more condensed microstructure. Tensile strength, abrasion resistance, heat deflection temperature and shore hardness of nanocomposites were found to be higher than that of pristine polymer. Impact strength decreased with an increase in the nano-CaCO3 content. Thermal studies indicated single-step degradation under a nitrogen atmosphere. Scanning electron microscopy studies confirmed the uniform distribution of nano-CaCO3 at lower loading of nano-CaCO3 and microcracking occurred during wearing.
Characterisation of a metal mesh heating element for closed-loop resistance welding of thermoplastic composites
Authors: Villegas Irene Fernandez , Bersee Harald EN
Published: February 2013

Resistance welding is one of the most suitable and mature welding techniques for thermoplastic composites. It uses the heat generated at the welding interface when electric current flows through a resistive element, mostly a metal mesh. Closed-loop resistance welding relies on indirect temperature feedback from the weld line for process control. Its implementation is more complex than the most common open-loop welding, but on the contrary, it does not, in principle, require the definition of processing windows for each welding configuration and it allows for constant-temperature welding. The temperature at the welding interface can be indirectly monitored through the resistance of the heating element. The relationship between resistance and temperature, expected to be approximately linear for a metal mesh heating element, can then be used to translate the welding temperature into a target resistance value for the process-control routine. Despite the apparent straightforwardness of this procedure, the research results presented in this article prove that different types of characterization tests yield different resistance versus temperature relations for a metal mesh heating element, which can lead to significant temperature deviations when used in closed-loop processes.
Development of novel chiral poly(amide–imide)/bionanocomposites containing N,N′-(pyromellitoyl)-bis-phenylalanine units reinforced by organoclay and modified TiO2
Authors: Mallakpour Shadpour , Ayatollahi Hesan
Published: February 2013

In the present investigation, novel optically active poly(amid–imide) (PAI)/organoclay (OC)/titanium dioxide (TiO2) bionanocomposite (BNC) films were prepared by solution intercalation method. These BNCs were synthesized by blending the chiral OC and modified TiO2 nanoparticles (NPs) with the PAI solution. An optically active PAI containing l-phenylalanine amino acid was synthesized via direct polycondensation reaction of N, N′-(pyromellitoyl)-bis-phenylalanine diacid 4 with 4,4′-diaminodiphenylsulfone 5 in the presence of molten tetrabutylammonium bromide as a green solvent. This polymer was end capped with amine end groups of diamine in the final polymerization process. Cloisite Na+ and protonated form of l-phenylalanine amino acid were used for the preparation of the chiral OC via ion-exchange reaction. The surface of TiO2 NPs was fictionalized by KH550 (γ-aminopropyltriethoxyl) coupling agent under ultrasonic irradiation. Finally, PAI/OC/TiO2 BNC films containing 5 wt% of the OC and 5, 10 and 15 wt% of modified TiO2 were prepared via solution intercalation technique. The resulting hybrid materials were subjected to Fourier transform infrared spectroscopy, thermogravimetric analysis techniques and x-ray diffraction. The morphology of the obtained materials was examined by transmission electron microscopy and field emission scanning electron microscopy techniques.
In situ monitoring of ultrasonic welding of thermoplastic composites through power and displacement data
Authors: Villegas Irene Fernandez
Published: February 2013

Ultrasonic welding is a very fast joining technique well suited for thermoplastic composites, which does not require the use of foreign materials at the welding interface for either carbon or glass fibre-reinforced substrates. Despite very interesting investigations carried out by several researchers on different aspects of the process, ultrasonic welding of thermoplastic composite parts is not well understood yet. This article presents a deep experimental analysis of the transformations and heating mechanisms at the welding interface and their relationship with the dissipated power and the displacement of the sonotrode as provided by a microprocessor-controlled ultrasonic welder. The main aim of this research is to build up the knowledge to enable straightforward monitoring of the process and ultimately of the weld quality through the feedback provided by the ultrasonic welder.
Composites from recycled polypropylene and rubberwood flour
Authors: Homkhiew Chatree , Ratanawilai Thanate , Thongruang Wiriya
Published: February 2013

The mechanical properties of composites from recycled waste plastic and waste sawdust are of interest in trying to convert these waste streams to useful products. The development of these composites from natural fiber is therefore receiving widespread attention due to the growing environmental awareness. The effects of compositions were investigated including different grades of plastic (virgin and recycled) and amounts of wood flour, coupling agent, and ultraviolet (UV) stabilizer on mechanical and physical properties of polypropylene/rubberwood flour (RWF) composites. Virgin polypropylene gave better mechanical properties than recycled (recycled polypropylene (rPP)), both in composites and as unfilled plastic. RWF content exceeding 25 wt% enhanced the strength of RWF-reinforced rPP composites. The modulus and hardness of composites increased linearly with wood flour loadings. Maleic anhydride-grafted polypropylene (MAPP) as a coupling agent increased the strength, modulus, and hardness of the composites. However, addition of 1 wt% UV stabilizer degraded the mechanical properties. Therefore, 4 wt% MAPP content is recommended to achieve good mechanical properties of rPP/RWF composites, while the amount of UV stabilizer should be as small as possible to avoid its negative influence.
Mechanical characterization of polyhydroxyalkanoate and poly(lactic acid) blends
Authors: Loureiro NC , Esteves JL , Viana JC , Ghosh S
Published: February 2013

In this work, the mechanical behavior of polyhyroxyalkanoate (PHA)/poly(lactic acid) (PLA) blends is investigated in a wide range of compositions. The mechanical properties can be optimized by varying the PHA contents of the blend. The flexural and tensile properties were estimated by different models: the rule of mixtures, Kerner–Uemura–Takayanagi (KUT) model, Nicolai–Narkis model and Béla–Pukánsky model. This study was aimed at investigating the adhesion between the two material phases. The results anticipate a good adhesion between both phases. Nevertheless, for low levels of incorporation of PHA (up to 30%), where PLA is expectantly the matrix, the experimental data seem to deviate from the perfect adhesion models, suggesting a decrease in the adhesion between both polymeric phases when PHA is the disperse phase. For the tensile modulus, a linear relationship is found, following the rules of mixtures (or a KUT model with perfect adhesion between phases) denoting a good adhesion between the phases over the composition range. The incorporation of PHA in the blend leads to a decrease in the flexural modulus but, at the same time, increases the tensile modulus. The impact energy of the blends varies more than 157% over the entire composition. For blends with PHA weight fraction lower than 50%, the impact strength of the blend is higher than the pure base polymers. The highest synergetic effect is found when the PLA is the matrix and the PHA is the disperse phase for the blend PHA/PLA of 30/70. The second maximum is found for the inverse composition of 70/30. PLA has a heat-deflection temperature (HDT) substantially lower than PHA. For the blends, the HDT increases with the increment in the percentage of the incorporation of PHA. With up to 50% PHA (PLA as matrix), the HDT is practically constant and equal to PLA value. Above this point (PHA matrix), the HDT of the polymer blends increases linearly with the percentage of addition of PHA.
Isothermal and nonisothermal crystallization kinetics of poly(ether ether ketone)/gadolinium oxide composites
Authors: Wang Haibin , Zhou Fugui , Wang Tingting , Zhang Hang , Liu Tao , Yang Yanhua
Published: February 2013

In this study, poly(ether ether ketone) (PEEK)/gadolinium oxide (Gd2O3) composites were prepared by melt extrusion in combination with a Haake rheometer. Differential scanning calorimetry was used to investigate the crystallization behavior of PEEK and its corresponding composites. The microstructural features of the composites and the interfacial interactions between the filler and PEEK phases were viewed with a scanning electron microscope. Gd2O3 powder was blended with PEEK, and sulfonated poly(ether ether ketone) (SPEEK) was used as the compatibilizer in the PEEK/Gd2O3 composites. Isothermal crystallization exotherms showed that the addition of SPEEK increased the crystallization of PEEK in PEEK/Gd2O3 composites. However, the PEEK crystallization rates decreased with increasing Gd2O3 fractions, which probably resulted from the Gd2O3 that had no heterogeneous nucleation effects on the matrix. The modified Avrami equation and Mo’s equation were used to study the nonisothermal crystallization kinetics. The addition of Gd2O3 did not change the nucleation process of PEEK, but it markedly decreased the crystal growth rate.
A numerical analysis of relationship between ductility and nucleation and critical void volume fraction parameters of Gurson–Tvergaard–Needleman model
Authors: Miloud M Hadj , Imad A , Benseddiq N , Bachir Bouiadjra B , Bounif A , Serier B
Published: February 2013

Gurson–Tvergaard–Needleman model is widely used to describe the three stages of ductile tearing: nucleation, growth and the coalescence of micro-voids. The aim of this article is to study the relationship between volume fraction of voids and the fracture strain ɛf. The effects of the volume fraction of nucleation, fN, and the critical volume fraction, fc, were analysed. These parameters play crucial roles in the process of ductile damage. A phenomenological analysis is carried out to study the relationship between the different void volume parameters and the fracture strain ɛf. A method is proposed for the determination of fN and fc, knowing the experimental fracture strain ɛf. The experimental parameters are extracted from the load–diametric contraction curve of an axisymmetric notched tensile bar test AN2.
Thermoacoustically controlled Helmholtz resonators
Authors: Matveev Konstantin I
Published: February 2013

Helmholtz resonators and their modifications are commonly applied for suppressing unwanted sound, including acoustic oscillations in chambers of propulsion and power systems. Sound absorption characteristics of Helmholtz resonators can be enhanced and controlled with a use of thermal stratification in porous insets inside resonators. A simplified lumped-element model for thermoacoustically augmented Helmholtz resonators is developed in this article. Sample calculations illustrate effects of temperature gradients, porosity, positions of porous insets, and locations of resonators inside chambers.
Longitudinal heavy haul train simulations and energy analysis for typical Australian track routes
Authors: Sun Yan , Cole Colin , Spiryagin Maksym , Godber Tony , Hames Stewart , Rasul Mohammad
Published: February 2013

Computer simulations are utilised to study the energy used by heavy haul trains and the amount of energy that can be generated from dynamic braking of these trains; these studies allow the potential for the application of hybrid locomotives to be evaluated. An in-house written software package is used to perform simulations on the energy balance between energy usage and the energy generated from dynamic braking for heavy haul operations on two typical track routes in Australia. The simulation results show that the energy generated from dynamic braking can contribute up to 30% of the energy used in locomotive traction. Detailed analyses show that the locomotives can operate at an average power that is much less than full power, and an energy hybridisation potential factor is defined, with the maximum factor reaching a value of 63%. This factor indicates the considerable potential for using hybrid locomotive traction in heavy haul applications.
Palliser’s Triangle: Reconstructing the ‘central desert’ of the southwestern Canadian prairies during the late 1850s
Authors: Wolfe SA , Hugenholtz CH , Lian Olav B
Published: February 2013

Between 1857 and 1860 the British North American Expedition, led by Captain John Palliser, explored and surveyed the Canadian Prairies primarily to establish its suitability for agriculture and settlement. Historical and paleoclimate records indicate the Expedition coincided with below normal precipitation, leading to the perception of an arid or semi-arid region that would ‘forever be comparatively useless’ for agriculture. Today, this part of the Canadian Prairies is known as the Palliser Triangle, and is Canada’s productive dryland agricultural region. Here we present historic, geomorphologic, and chronometric evidence to reconstruct the landscape encountered by the Expedition. We contend that Palliser’s perception of the region was strongly influenced by his experience travelling through active sand dunes in the Middle Sand Hills of southeastern Alberta. At present, the dunes are entirely stabilized by vegetation, in contrast to Palliser’s report of ‘miles of burning sand’. Archival aerial photographs and optical ages of near-surface samples are used to reconstruct the landscape encountered by the Expedition in the Middle Sand Hills. Optical ages of presently stabilized sand dunes date primarily to between ad 1850 and 1934, peaking in c. ad 1925, and are indicative of a dune field undergoing reduction in activity, prior to the onset of 20th century droughts. Ages of interdune sand sheets further attest to regional dune activity occurring at least since ad 1750, concurrent with activity in other southern Canadian Prairie dune fields. Collectively, this evidence supports observations by Palliser of severe travelling due to bare sand conditions in 1857–1859. These conditions and Palliser’s inference of their extent influenced his perception of a ‘central desert’, thus delaying construction of the Canadian Pacific Railway along a southern route and postponing the westward colonization of Canada.
800 years of vegetation change, fire and human settlement in the Sierra Nevada of California, USA
Authors: Anderson R Scott , Stillick Roger D
Published: February 2013

A combination of pollen and sedimentary charcoal stratigraphies are used in conjunction with historical records to determine the relationships between climate, vegetation change and changing disturbances over the last 800 years in the Sierra Nevada, California. This period witnessed significant climate variability (the ‘Medieval Climate Anomaly’ followed by the ‘Little Ice Age’), as well as expansion of Native American, then Euro-American, populations. From c. ad 1300 to about ad 1800, the meadow was surrounded by a Pinus ponderosa–mixed conifer forest. The abundance of charcoal and carbonaceous spheres in the sediments suggests fire repeatedly burned across the meadow between c. ad 1300 and c. ad 1550, suggesting frequent surface fires. A similar pattern was noted previously in nearby Yosemite Valley, associated with a proto-historic Miwok population expansion (Anderson and Carpenter, 1991). Subsequently, cooler conditions with greater meadow soil moisture prevailed during the LIA, but with little decline in burning. We interpret this as evidence for continued Native American burning. Beginning in the mid-19th century ce, pine pollen percentages declined substantially, then rebounded somewhat during the 20th century. Grass pollen increases, and introduced herbs ( Erodium, Plantago, Rumex, Zea) increase, documenting Euro-American settlement of the local Wawona area, with harvesting of economically important trees, livestock grazing and small-scale farming. These changes are consistent with the historical record. The sedimentary record largely confirms the fire scar record, documenting the anomalous nature of the absence of fire in the vicinity, which is critical to our understanding of the importance of this process on pre-European landscapes.
Shieling activity in the Norse Eastern Settlement: Palaeoenvironment of the ‘Mountain Farm’, Vatnahverfi, Greenland
Authors: Ledger Paul M , Edwards Kevin J , Schofield J Edward
Published: February 2013

Transhumance agriculture formed a key component of subsistence strategies in the Norse economies of the North Atlantic, with evidence of shielings or sæters found in Norway, Scotland, the Faroe Islands and Iceland. It is frequently assumed to have played a role in Norse Greenland, yet little enquiry has been made into such activity. This paper seeks to address this deficit, presenting the first palaeoenvironmental study of a suspected Greenlandic shieling site in the uplands of the former Norse Eastern Settlement. Pollen analysis, 14C and associated proxies are used to date and assess the environmental and landscape impact of shieling activity. Evidence for vegetation disturbance associated with Norse settlement is indicated from c. ad 985, but the shieling itself is interpreted as having been established somewhat later (cal. ad 1050–1150). Initially the site appears to have been used exclusively for grazing of livestock and there is tentative evidence for the use of burning to stimulate the spread of pastures. Pollen influx figures suggest the intensification, or initiation, of hay production c. cal. 1225–1325 reflecting either the spread of settlement from the lowland valleys, or evolution of the site into a full farm in response to population pressure. A reduction of human impact cal. ad 1300–1390 suggests a reversion to shieling activity, indicating similarities to transhumance in northern Iceland. Abandonment of the site dates to cal. ad 1325–1415 and is in agreement with previous evidence from Norse Greenland.
Land-use changes and environmental dynamics in the upper Rhone valley since Neolithic times inferred from sediments in Lac Moras
Authors: Doyen Élise , Vannière Boris , Berger Jean-François , Arnaud Fabien , Tachikawa Kazuyo , Bard Edouard
Published: February 2013

Lac Moras is a small lake located on a low-elevation plateau in the upper Rhône Valley (304 m a.s.l.). The upper 5 m of accumulated sediment in the lake span 7500 years and offer a detailed record of environmental perturbations and land-use history at a local scale. A multiproxy analysis (pollen, charcoal and geochemical parameters) led to the establishment of four periods of landscape dynamics. The first evidence of human impacts was recorded during the Neolithic and Bronze Age (6000–2700 cal. BP). These impacts were temporary and most likely affected small areas. The second period, in the Iron Age/classical antiquity (2200–1900 cal. BP), appears to be a key period in which the intensification of anthropogenic pressure (primarily grazing with localised areas of cultivation) caused high-intensity erosion events and deeply affected soil stability. During the Middle Ages, wheat, rye and hemp cultures as well as tree farming (walnut, chestnut) were intensively developed. From 50 cal. BP (the 19th century) onward, crop cultivation declined and was gradually replaced by meadows and pastures. According to these transformations in agro-pastoral practices, the associated use of fire changed. Whereas fire was used intensively to clear wild areas from the Neolithic to the early Middle Ages, its use was restricted to cleaning agro-pastoral areas during the second part of the Middle Ages. These periods correspond to the different reconstructed types of land use. These changes correspond to population growth, the evolution of settlement patterns and the increase in agrarian productivity by technological advances. The present landscape is a result of this coupled agrarian and environmental history. It is notable that the first permanent alteration occurred as early as classical antiquity.
Geoengineering, news media and metaphors: Framing the controversial
Authors: Luokkanen Matti , Huttunen Suvi , Hildén Mikael
Published: February 2013

We analyze how metaphors are used in presenting and debating novel technologies that could influence the climate and thereby also future climate change policies. We show that metaphors strengthen a policy-related storyline, while metaphors are rarer in purely descriptive accounts. The choice of metaphor frames the technologies. War metaphors are used equally in arguments that are for, against and neutral with respect to the further development of geoengineering, but differences arise in the use of metaphors related to controllability, health and mechanisms. Controllability metaphors are often used in justifying further research and development of good governance practices, whereas health metaphors tend to be used against the very idea of geoengineering by portraying technological interventions in the climate as an emblematic case of an unacceptable development. These findings suggest that metaphors are early indications of restrictions in the interpretative flexibility that influences future governance of geoengineering and geoengineering research.
The Impacts of Fear and Disgust on the Perceived Effectiveness of Smoking Warning Labels
Authors: Tugrul Tugba Orten
Published: February 2013

This study investigated the perceived effectiveness of pictorial warning labels on cigarette packages on Turkish university students. In particular, the impacts of fear and disgust elicited by these labels were examined using the smoking decision process model. A survey was conducted with 344 undergraduate students at a private university in Izmir, the third largest city of Turkey. The findings showed differences in levels of fear and disgust evoked by pictorial warning labels for each stage in the smoking decision process, which in turn led to differences in the perceived effectiveness of the labels. Thus, this study underlines the importance of tailoring antismoking messages according to specific target groups and also suggests considering the smoking-decision-process model as segments and targeting groups in creating effective messages.
The Impact of Health Care Resources, Socioeconomic Status, and Demographics on Life Expectancy
Authors: Chan Moon Fai
Published: February 2013

This study aimed to examine the impact of health care resources, socioeconomic status, and demographic changes on life expectancy in Indonesia, Philippines, and Vietnam. This was a cross-country study to collect annual data (1980-2008) from each target country. Life expectancy was the dependent variable and health care resources, socioeconomic status, and demographics were the 3 main determinants. Structural equation modeling was employed, and the results indicate that the availability of more health care resources (Indonesia: coefficient = .47, P = .008; Philippines: coefficient = .48, P = .017; Vietnam: coefficient = .48, P = .004) and higher levels of socioeconomic advantages (Indonesia: coefficient = .41, P = .014; Vietnam: coefficient = .34, P = .026) are more likely to increase life expectancy. In contrast, demographic changes are more likely to increase life expectancy because of the wide range of health care resources. These findings suggest that more effort, particularly during economic downturns, should be put into removing the barriers that impede access to health care services and increasing preventive care for the population that currently has less access to health care in communities where there is a shortage of medical resources.
The Adherence to Medications in Diabetic Patients in Rural Kerala, India
Authors: Sankar Uma V. , Lipska Kasia , Mini G. K. , Sarma P. S. , Thankappan K. R.
Published: February 2013

We conducted a study to determine medications adherence and factors associated with poor adherence in community-dwelling adults with diabetes in southern India. A cross-sectional survey was conducted among 346 diabetes patients selected using multistage cluster sampling. The 8-item Morisky Medication Adherence Scale was used to collect information on adherence. Prevalence of poor adherence was 74% (95% confidence interval = 69.2-78.3). Multiple regression analysis showed that patients using oral hypoglycemic agents, who had lower per capita monthly expenditure, those with irregular blood sugar monitoring, who received limited diabetes management instructions from health professionals, who resorted to only symptomatic management, and those who did not receive family member’s help to remember medications were more likely to report poor adherence compared with their counterparts. Interventions for patients using oral hypoglycemic agents, with lower expenditure, with irregular blood sugar monitoring, and which focus on better education and enhanced family support, are likely to enhance adherence in this population.
The Effect of Comprehensive Sexual Education Program on Sexual Health Knowledge and Sexual Attitude Among College Students in Southwest China
Authors: Chi Xinli , Hawk Skyler T. , Winter Sam , Meeus Wim
Published: February 2013

The purpose of this study was to evaluate whether a comprehensive sexual education program for college students in Southwest China ( a) improved sexual health knowledge in reproduction, contraception, condom use, sexually transmitted diseases, and HIV; ( b) increased accepting attitudes toward lesbian, gay, bisexual, and transsexual individuals; and ( c) altered participants’ attitudes toward premarital sex and monogamy. The program used diverse teaching methods, providing 6 sessions over a period of 9 weeks about sexual health knowledge and sexual attitudes to college students (age 18-26 years) in Southwest China. Sexual health knowledge and sexual attitudes of 80 comprehensive sexual education class students (education group) and 92 general mental health education class students (control group) were measured at baseline, the end of course (posttest), and 3 weeks after the end of course (follow-up). There were significant effects of the program on ( a) sexual health knowledge, including reproductive health, contraception, condom use, and HIV/AIDS and ( b) positive attitudes toward sexual minorities, although these changes may require further reinforcement. In contrast, the program did not alter students’ attitudes about premarital sex or monogamy. The results are discussed in terms of recommendations of sex education in China and future directions for research.
Patterns of Work-Related Musculoskeletal Disorders Among Workers in Palm Plantation Occupation
Authors: Henry Leonard Joseph , Jafarzadeh Esfehani Ali , Ramli Ayiesah , Ishak Ismarulyusda , Justine Maria , Mohan Vikram
Published: February 2013

This study investigated the patterns of ongoing work-related musculoskeletal disorders (WRMDs) and exposure risk to musculoskeletal injuries for various body regions among palm plantation workers. Standard Nordic Musculoskeletal Questionnaire (SNMQ) was used to assess the prevalence of musculoskeletal disorders symptoms. The Quick Exposure check (QEC) was used to assess the exposure risk of farmers to WRMDs. The common pattern of WRMDs was back pain (40%), followed by shoulder pain (19%). The QEC revealed high exposure risk for neck (56%), followed by back (45.6%). The results from the SNMQ showed that 58% reported pain in 1 region, followed by 2 regions (10.7%) and 3 regions (3.6%). Back pain and shoulder pain were found to be common among workers in palm plantation occupation. Nevertheless, the neck region appeared to have the highest risk of exposure to injuries.
A β-mercaptoethanol–modified enzyme-linked immunosorbent assay for diagnosis of canine visceral leishmaniasis
Authors: Barral-Veloso Laura , Semião-Santos Saul J. , de Andrade Paulo P. , de Melo Marcia A. , Martins Luís , Marinho Artur A. , de Almeida José A. A. , Cardoso Luís , el Harith Abdallah
Published: February 2013

Two immunoglobulin G enzyme-linked immunosorbent assay (ELISA) versions using whole promastigotes of Leishmania infantum (syn. Leishmania chagasi) treated either with β-mercaptoethanol (β-ME-ELISA) or trypsin (TRYP-ELISA) as antigens were developed for the diagnosis of canine visceral leishmaniasis (CVL). By comparison with the direct agglutination test (DAT; 100%, 31/31; 95% confidence interval [CI]: 86.3–100%), slightly lower sensitivity was demonstrated for the newly developed β-ME-ELISA (93.5%, 29/31; 95% CI: 77.2–98.9%). Sensitivity was higher for β-ME-ELISA compared with TRYP-ELISA (87.1%, 27/31; 95% CI: 69.2–95.8%) in serum samples from dogs with CVL. When tested with sera from 37 healthy dogs and from 45 dogs with clinical conditions other than CVL, a specificity of 97.6% (80/82; 95% CI: 90.1–99.6%) was estimated for β-ME-ELISA as compared to 100% (82/82; 95% CI: 94.4–100%) and 95.1% (78/82; 95% CI: 87.3–98.4%) for DAT and TRYP-ELISA, respectively. Observed agreement was 94.0% (95% CI: 88.7–97.1%) between DAT and β-ME-ELISA (κ = 0.879; 95% CI: 0.803–0.956) and 87.4% (95% CI: 80.8–92.1%) between DAT and TRYP-ELISA (κ = 0.743; 95% CI: 0.636–0.851). Current results advocate application of the new β-ME-ELISA for diagnosis of CVL at the laboratory level and confirmation of results obtained with the DAT in field studies.
Effect of transportation, time of sampling, and lymphocyte numbers on gamma interferon response to Mycobacterium bovis in cattle at time of slaughter
Authors: Okafor Chika C. , Grooms Daniel L. , Bolin Steven R. , Gravelyn Tara D. , Kaneene John B.
Published: February 2013

Adapting the gamma interferon (IFNγ) assay for tuberculosis screening at points-of-concentration of cattle would improve global efforts to eradicate bovine tuberculosis. Two separate studies were conducted to evaluate if transportation of cattle, the time of blood collection, and total lymphocyte count affects the retention of a positive IFNγ assay result during slaughter of cattle experimentally sensitized with inactivated Mycobacterium bovis. Study 1 evaluated IFNγ assay responses to M. bovis and Mycobacterium avium stimulations in 5 cows (4 sensitized and 1 control) at the housing facility, after a 30-min transport to the slaughter facility, immediately before stunning, at commencement of exsanguination, and at 5 min after exsanguination commenced. Study 2 evaluated IFNγ assay responses to Mycobacterium antigen stimulations and total lymphocyte count in blood collected from 5 steers (4 sensitized and 1 control) at the housing facility, at commencement of exsanguination and at 2 successive 1-min intervals. The results indicated that blood obtained from sensitized cattle at commencement of exsanguination was more likely to remain positive than blood collected at successive time points; hence the time of blood collection is crucial to obtaining a useful IFNγ assay result for bovine tuberculosis at slaughter. The lymphocyte count progressively declined following exsanguination, and this decline might contribute to the reduction in the measured IFNγ. To compensate for the reduction in IFNγ production, a different set of positive cutoff values might be needed for blood collected at exsanguination. The current findings provide useful preliminary information necessary for making changes to the interpretation of the IFNγ assay on blood collected during exsanguination.
An outbreak of aflatoxin poisoning in dogs associated with aflatoxin B1–contaminated maize products
Authors: Wouters Angelica Terezinha Barth , Casagrande Renata Assis , Wouters Flademir , Watanabe Tatiane Terumi Negrão , Boabaid Fabiana Marques , Cruz Cláudio Estêvão Farias , Driemeier David
Published: February 2013

An aflatoxicosis outbreak affected 65 dogs from 9 different farms after they were fed diets with cooked corn meal as a common ingredient. Of the dogs, 60 died. Numerous dogs died on additional farms, but those dogs were not included in the study. The farmers acquired the contaminated maize products, in the form of whole corn grain or as corn meal, from the same supplier. The corn product was mixed with meat that was left over from home or commercial rations to form corn polenta, which was fed to the dogs. Necropsy was performed on 3 dogs. Two of the dogs died after a few days of refusing food, showing anorexia, polydipsia, icteric mucous membranes, hematemesis, hematochezia, or melena, and bleeding of the skin, eye, ear, and mouth. The primary necropsy findings included jaundice, hemorrhages in several organs, and yellowish enlarged liver with enhanced lobular pattern. The dog that experienced chronic ascites had a yellowish liver with reduced volume, irregular surface, and increased consistency. The main histological findings included hepatocyte fatty degeneration, biliary duct hyperplasia, cholestasis and, in the chronic case, hepatic fibrosis. High-performance liquid chromatography analysis of the corn meal from 2 affected farms revealed 1,640 ppb and 1,770 ppb of aflatoxin B1, respectively. The current study demonstrates an additional way that dogs can be exposed to, poisoned, and killed by aflatoxin.
Preliminary evaluation of a quantitative ethylene glycol test in dogs and cats
Authors: Scherk Jordan R. , Brainard Benjamin M. , Collicutt Nancy B. , Bush Sharon E. , Almy Frederick S. , Koenig Amie
Published: February 2013

Ethylene glycol (EG) toxicity is commonly encountered in dogs and cats. The purpose of the current study was to determine if the Catachem test kit (Catachem Inc., Oxford, Connecticut) could precisely and accurately detect the presence of EG added to serum and plasma from 6 dogs and 4 cats. Serum and plasma samples were spiked at various concentrations of EG (0, 20, 60, and 100 mg/dl) and analyzed using the Catachem kit. Twenty randomly selected samples were also submitted for gas chromatography–mass spectroscopy (GC-MS) analysis of EG concentration, which was considered the gold standard. Inter- and intra-assay coefficients of variation (CVs) were calculated. Bland–Altman analysis was performed to compare the Catachem results to the GC-MS analyses. Analysis of serum samples showed a bias of 8.48 mg/dl (95% limits of agreement: 17.8 to −0.9 mg/dl) while spiked plasma samples had a bias of 7.32 mg/dl (18.1 to −3.5 mg/dl). Intra-assay CV was 0.7%. Interassay CV ranged from 1.2% to 2.0%. For all samples, the Catachem kit read higher than GC-MS values and slightly overestimated in vitro concentrations. The Catachem test kit is an accurate quantitative test for EG in dogs and cats that may aid in timely recognition of EG exposure. Because of the positive bias in all samples, some pets may receive treatment unnecessarily. However, animals with blood EG concentrations at or above the published lethal serum or plasma concentration will be readily identified so that treatment may be initiated.
Detection of Bovine viral diarrhea virus–specific neutralizing antibodies in fresh colostrum
Authors: Bedeković Tomislav , Mihaljević Željko , Jungić Andreja , Lemo Nina , Lojkić Ivana , Cvetnić Željko , Čač Željko
Published: February 2013

To eliminate cytotoxic effects of colostrum on cells, a modified virus neutralization test (VNT) for the detection of Bovine viral diarrhea virus–specific neutralizing antibodies in colostrum was developed. The new test was compared to the World Organization for Animal Health–recommended VNT and the results evaluated. The agreement of the new test compared to the standard VNT was determined to be 98%, whereas sensitivity and specificity of the modified VNT compared to the standard VNT were 100%. Bovine viral diarrhea virus–specific antibodies were detected in 42 sera samples and 38 colostrum samples. The antibody titers in serum and colostrum showed a high correlation ( n = 56, r = 0.9719, P < 0.001). The modified virus neutralization technique described herein succeeds in eliminating cytotoxic effects and can be readily applied for the detection of specific antibodies against other infectious agents in colostrum.
Leukocyte adhesion deficiency type I in a mixed-breed dog
Authors: Zimmerman Kurt L. , McMillan Kate , Monroe William E. , Sponenberg D. Phillip , Evans Nick , Makris Melissa , Hammond Sarah H. , Kanevsky Mullarky Isis , Boudreaux Mary K.
Published: February 2013

A 6-month-old, neutered male, mixed-breed dog was examined for a 2-month persistent fever, nonhealing dermal metacarpal area wound, and leukocytosis (47.0–198.0 × 103/μl). Serum chemistry findings included hypoalbuminemia, hyperglobulinemia, hyperphosphatemia, and hyperphosphatasemia. Complete blood cell count results revealed a moderate microcytic, hypochromic nonregenerative anemia with a profound leukocytosis (198.5 × 103/μl), characterized by neutrophilia with toxicity and hypersegmentation, and significant band cells. Tick-borne disease titers (genera Anaplasma, Ehrlichia, and Borrelia) were negative, as were polymerase chain reaction for other infectious agents (genera Hepatozoon, Mycobacterium, Mycoplasma; and Canine distemper virus). No agents were identified in a deep dermal biopsy (conventional and special histochemical stains) of the chronic draining, metacarpal region lesion. Cytology of the draining tract revealed numerous mixed bacteria and a surprising lack of neutrophils. Chronic occult blood loss with iron deficiency was considered a possible cause of the anemia. Differentials for the leukon were chronic established inflammation (occult infectious agent), chronic neutrophilic leukemia, paraneoplastic leukocytosis (neoplastic source of granulocyte colony-stimulating factor [CSF] or granulocyte-macrophage CSF), and leukocyte adhesion deficiency (LAD). The possibility of a LAD disorder was further investigated because of the noted hypersegmented neutrophils, absence of neutrophils in the cytology sample, the animal’s young age, and persistence of clinical and laboratory signs. Flow cytometry of blood neutrophils showed a 60% reduction in surface expression of the β2-integrin (CD18) subunit, whereas neutrophil function tests (oxidative burst and phagocytosis) were normal. Genetic testing revealed a homozygous missense mutation in the β2-integrin subunit gene, previously recognized only in purebred Irish Setters, leading to a diagnosis of LAD type 1 disorder in this mixed-breed dog.
Estimation of fracture properties for high strength and ultra high strength concrete beams and size effect
Authors: Murthy A Ramachandra , Prasad BK Raghu , Iyer Nagesh R
Published: February 2013

This article presents the details of estimation of fracture parameters for high strength concrete (HSC, HSC1) and ultra high strength concrete (UHSC). Brief details about characterization of ingredients of HSC, HSC1 and UHSC have been provided. Experiments have been carried out on beams made up of HSC, HSC1 and UHSC considering various sizes and notch depths. Fracture characteristics such as size independent fracture energy ( Gf), size of fracture process zone ( Cf), fracture toughness ( KIC) and crack tip opening displacement (CTODc) have been estimated based on the experimental observations. From the studies, it is observed that (i) UHSC has high fracture energy and ductility inspite of having a very low value of Cf; (ii) relatively much more homogeneous than other concretes, because of absence of coarse aggregates and well-graded smaller size particles; (iii) the critical SIF ( KIC) values are increasing with increase of beam depth and decreasing with increase of notch depth. Generally, it can be noted that there is significant increase in fracture toughness and CTODc. They are about 7 times in HSC1 and about 10 times in UHSC compared to those in HSC; (iv) for notch-to-depth ratio 0.1, Bazant’s size effect model slightly overestimates the maximum failure loads compared to experimental observations and Karihaloo’s model slightly underestimates the maximum failure loads. For the notch-to-depth ratio ranging from 0.2 to 0.4 for the case of UHSC, it can be observed that, both the size effect models predict more or less similar maximum failure loads compared to corresponding experimental values.