bluuebunny/crossref_metadata_2025 huggingface dataset:
Faecal sludge in Accra, Ghana: problems of urban provision
Authors: Boot N. L. D. , Scott R. E.
Published: August 2009

Urban on-site sanitation services present challenges for emptying, transporting, disposing and treating faecal waste. Transfer stations can be used by household-level emptiers to safely dispose of faecal sludge, but they rarely exist. Accra's use of transfer stations has provided an opportunity to research their functioning, as part of broader faecal sludge management arrangements. The paper discusses the benefits offered by use of transfer stations, as well as reasons currently limiting their operation. While costs associated with operating and emptying these stations are passed to householders, an illegal sector thrives offering lower cost emptying services, typically with disposal of faecal sludge directly into the environment. At present, bucket latrines offer sanitation services to low-income households unable to afford higher service levels, such as septic tanks. The local government aims to phase-out all bucket latrines by 2010, but affordable alternatives have not been found. Where limited access to land inhibits investment in permanent facilities, families may abandon household sanitation altogether. The paper concludes that correct use of transfer stations can provide improvements for existing faecal sludge management and reduce indiscriminate dumping. They must be made available to all workers, through effective public-private arrangements for ownership and operation.
Perceptions of water, sanitation and health: a case study from the Mekong Delta, Vietnam
Authors: Herbst S. , Benedikter S. , Koester U. , Phan N. , Berger C. , Rechenburg A. , Kistemann T.
Published: August 2009

In the Mekong Delta in the south of Vietnam about 5.7 million people lack access to safe drinking water and 10 million people in rural areas live without adequate sanitation. Between May and August, 2007 a survey was carried out in An Bin, a peri-urban ward in the Mekong Delta, to gain insight into water, sanitation and health as well as to health-related hygiene behaviour. The study employed a combination of quantitative (standardized questionnaire) and qualitative (focus group discussions, semi-structured interviews) methods. The most important features in the choice of drinking water sources are matters of hygiene and the taste of the water. The majority (74%) of the 120 households surveyed indicated their ownership of a sanitation facility, but the fish pond toilet (64%) which is predominantly utilized is considered to be unimproved sanitation. The local peri-urban population link water and hygiene to health, but sanitation instead to environmental pollution. This and other outcomes lead to the assumption that people have a basic knowledge of proper hygiene behaviour. However, hygiene measures such as hand washing are put into practice in an untimely manner, most likely due to a misconception of risks and/or a lack of background knowledge of cause–effect relationships as well as ingrained habits.
Should we Recommend Stethoscope Disinfection Before Daily Usage as an Infection Control Rule?
Authors: Alothman A. , Bukhari A. , Aljohani S. , Muhanaa A.
Published: August 2009

Background:

Many studies have shown that contaminated medical equipments act like a vector for crossinfection.
Infection control programmes are effective in decreasing hospital-acquired infection rate, however, the
implementation of such programmes is hindered by poor compliance of health care workers.
Methods: Random selection of health care workers, at our institution, was given questionnaires and were asked to give
their stethoscopes to be sampled.

Methods:

Random selection of health care workers, at our institution, was given questionnaires and were asked to give
their stethoscopes to be sampled.

Results:

151 health care workers were involved in this study. Physicians were 79/151 and their stethoscopes were found to
be the most contaminated (68.3%). The total number of contaminated stethoscopes was 72/151 (47.7%). Coagulasenegative
staphylococcus was isolated from 66 diaphragms from 72 (92%).

Conclusion:

Nosocomial infections carry a higher level of morbidity and mortality. This study showed that there is lack of
good compliance with routinely disinfecting the health care workers stethoscopes. We recommend that the significance of
disinfecting diaphragms of stethoscopes should be clarified to the health care workers.
Trends in Daily Rainfall Intensity Over Israel 1950/1-2003/4
Authors: Yosef Yizhak , Saaroni Hadas , Alpert Pinhas
Published: August 2009

The study focuses on long-term trends of daily rainfall in Israel as a function of their intensity in order to identify potential trends in rainfall extremity. The study period is the rainy season, October-May between 1950/1 and 2003/4. For the total rainfall, an increased trend is shown across Israel, especially for the central and southern regions, though non-significant. Daily rainfall intensity showed non-significant trends of increase in the heavy rainfall at the center and south and decrease at the north. The light to moderate rainfall trends increased in the north while they decreased at the center and south. Trends are significantly correlated with known teleconnection patterns, especially the East Atlantic- Western Russia and the North Sea-Caspian Sea patterns. Positive trends toward heavier rainfall are noted in Israel, which are significant in several specific locations. This finding has to be carefully followed since the region is a climatic border subjected to severe water shortage and is predicted to dry-up in most global warming scenarios.
Osteochondral Grafting: Effect of Graft Alignment, Material Properties, and Articular Geometry
Authors: D. D’Lima Darryl , C. Chen Peter , W. Colwell Jr. Clifford
Published: August 2009

Osteochondral grafting for cartilage lesions is an attractive surgical procedure; however, the clinical results have not always been successful. Surgical recommendations differ with respect to donor site and graft placement technique. No clear biomechanical analysis of these surgical options has been reported. We hypothesized that differences in graft placement, graft biomechanical properties, and graft topography affect cartilage stresses and strains. A finite element model of articular cartilage and meniscus in a normal knee was constructed. The model was used to analyze the magnitude and the distribution of contact stresses, von Mises stresses, and compressive strains in the intact knee, after creation of an 8-mm diameter osteochondral defect, and after osteochondral grafting of the defect. The effects of graft placement, articular surface topography, and biomechanical properties were evaluated. The osteochondral defect generated minimal changes in peak contact stress (3.6 MPa) relative to the intact condition (3.4 MPa) but significantly increased peak von Mises stress (by 110%) and peak compressive strain (by 63%). A perfectly matched graft restored stresses and strains to near intact conditions. Leaving the graft proud by 0.5 mm generated the greatest increase in local stresses (peak contact stresses = 6.7 MPa). Reducing graft stiffness and curvature of articular surface had lesser effects on local stresses. Graft alignment, graft biomechanical properties, and graft topography all affected cartilage stresses and strains. Contact stresses, von Mises stresses, and compressive strains are biomechanical markers for potential tissue damage and cell death. Leaving the graft proud tends to jeopardize the graft by increasing the stresses and strains on the graft. From a biomechanical perspective, the ideal surgical procedure is a perfectly aligned graft with reasonably matched articular cartilage surface from a lower load-bearing region of the knee.
Selective Stimulation of C Fibers by an Intra-Epidermal Needle Electrode in Humans
Authors: Otsuru Naofumi , Inui Koji , Yamashiro Koya , Miyazaki Takahiro , Ohsawa Ichiro , Takeshima Yasuyuki , Kakigi Ryusuke
Published: August 2009

We recorded evoked potentials (EPs) induced by intra-epidermal electrical stimulation using a needle electrode with specific parameters. We identified the fibers activated by this specific stimulation by assessing the conduction velocity (CV) of the peripheral nerve. The EPs were recorded from the Cz electrode (vertex) of the International 10-20 system in ten healthy male subjects. The dorsum of the left hand and forearm were stimulated with an intensity of 0.01 mA above the sensory threshold. The mean P1 latency of EPs for the hand and forearm were 1007 ± 88 and 783 ± 80 ms, respectively, and the CV estimated from the latency of P1 was 1.5 ± 0.7 m/s. The CV indicated that the fibers activated by the stimulation were C fibers. Since the method of stimulation is convenient and non-invasive, it should be useful for investigating the functions of small fibers.
Bachelor's Degree Productivity X-Inefficiency: The Role of State Higher Education Policy
Authors: Titus Marvin A.
Published: August 2009

Using stochastic frontier analysis and dynamic fixed-effects panel modeling, this study examines how changes in the x-inefficiency of bachelor's degree production are influenced by changes in state higher education policy. The findings from this research show that increases in need-based state financial aid help to mitigate the convergence among states in x-inefficiency with regard to bachelor's degree production.
Previously Homeschooled College Freshmen: Their First Year Experiences and Persistence Rates
Authors: Saunders Mary K.
Published: August 2009

Utilizing survey research on the entire 2004–2005 freshmen class of a private, interdenominational Christian college ( n = 261), this study examined the social experiences and persistence rates of college freshmen who were homeschooled prior to attending higher education, and compared this group to college freshmen who were educated in a classroom setting. Findings revealed that homeschooling positively affects two variables proposed as antecedents to the social integration process—the variables of communal potential and institutional integrity. Additionally, homeschooling was found to be positively correlated with the variable of subsequent institutional commitment to the institution of higher education. Subsequent institutional commitment affects the students' persistence rates into their sophomore year.
Cataloging and Comparing Institutional Efforts to Increase Student Retention Rates
Authors: Jones Willis A. , Braxton John M.
Published: August 2009

College student retention has been and continues to be one of the most important issues facing the higher education community. Despite this importance, little is known about the type and methodological rigor of institutional efforts to increase student retention. This article presents the findings of a study which attempted to gain a clearer picture of the types of activities institutions of higher education are engaged in with respect to the understanding and reducing of student dropout. Findings suggest the need for institutions to engage in more methodologically rigorous studies of student retention and the need for greater transparency from institutions with regard to the types of activities they are engaged in to address retention.
Influence of an Identified Advisor/Mentor on Urban Latino Students' College Experience
Authors: Torres Vasti , Hernandez Ebelia
Published: August 2009

This study considers the scales previously used by Nora, Kraemer, and Itzen (1997) and Torres (2006) as contributing to the retention of Latino/a college students. T-tests were used to compare the scale means between students with an identified advisor or mentor and those that have not identified one. The data is from Latino college students at three urban universities who were surveyed each spring for 3 years. Using longitudinal data, the results indicate that students with an advisor/mentor consistently have higher levels of institutional commitment, satisfaction with faculty, academic integration, cultural affinity, and encouragement.
Comparative Experiment on Hot-Air and Microwave-Vacuum Drying and Puffing of Blue Honeysuckle Snack
Authors: Liu Chenghai , Zheng Xianzhe , Jia Shuhua , Ding Ningye , Gao Xiaochen
Published: August 2009

A comparative drying experiment between the hot-air and microwave-vacuum method of blue honeysuckle slice has been completed. In hot-air drying, the temperature was 50°C when the velocity of air stream was kept at 0.5 m/s. In microwave-vacuum puffing, the microwave power and vacuum pressure were set at 2.68kW and 82 kPa, respectively. Comparing to the quality indexes viz. texture characteristics (hardness and crispness), color, cross-section structure and vitamin C content of blue honeysuckle snack, it was known that hardness of blue honeysuckle snack decreased by 3936g, crispness increased by 3, value of lightness, redness and yellowness increased by 2.09, 0.2, 0.27, respectively, and the retention rate of VC content increased by 9.67% using microwave-vacuum puffing than that using hot-air drying. Therefore, microwave-vacuum technique is a potential method to puff blue honeysuckle slices with high quality attributes.
Effect of Operating Decisions on the Design and Energy Consumption of Inverted Batch Distillation Column
Authors: Masoud Aboubaker Z , Mujtaba Iqbal M
Published: August 2009

In this paper, the effect of operating decisions on the design and energy consumption for inverted batch distillation is considered. In distillation, utility cost is a function of column vapour load (V). We present a different type (as compared to what is available in the existing literature) of optimisation problem formulation and show that for a fixed market demand scenario minimisation of V for a given N will not only minimise the utility cost (cooling water + energy cost) and the capital cost but will also maximise the profitability of the operation. Also, with several examples of binary separation, it is shown that the decision of operating policy (such as constant reboil ratio, time dependent reboil ratio, etc.) at the design stage can have a significant impact on the capital and utility cost and overall profitability. This will in turn have significant effect on global warming as savings in utility cost reflects savings in energy cost. For difficult separations, which are capital and energy intensive, 40% savings in capital cost, 60% savings in utility and 70% improvement in profitability are possible if operating decisions are taken at the design stage.
Polynomial reconstruction of staggered unstructured vector fields
Authors: Vidovic Dragan
Published: August 2009

Polynomial reconstruction of staggered unstructured vector fields has been considered. Coefficients of such polynomials are determined by the least squares method. Reduction in the rank of the least squares systems caused by the over-specification of the divergence may lead to difficulties. This has been investigated. The rank of these systems may be further reduced depending on the mesh geometry, or they may become ill conditioned. Guidelines for solving such linear systems have been presented.
Explicit solutions for partial differential equations of Lord-Shulman thermoelasticity
Authors: Rodionov A.
Published: August 2009

We consider the Lord-Shulman model of thermoelasticity with one relaxation constant. The corresponding system of four linear partial differential equations is solved by means of holomorphic expansions. We prove the convergence of expansions and study the possibility to convert them in finite sums.
Kaluza-Klein FRW cosmological models in Lyra manifold
Authors: Mohanty G. , Samanta G.C. , Mahanta K.L.
Published: August 2009

We have constructed five dimensional FRW cosmological models for k=-1,1,0 in Lyra manifold with time dependent displacement field. The matter field is considered in the form of a perfect fluid with isotropic matter pressure. It is found that the model for k=-1 is inflationary. For k=1, the model is inflationary for set of values of arbitrary constant n and decelerates in the standard way for another set of values of n. Moreover the concept of Lyra manifold does not exist at infinite time.
Overview of research of personal epistemologies: Analysis of research metaphors
Authors: Pavlovic Jelena
Published: August 2009

This paper presents developmental, cognitive and psychometric tradition in research of personal epistemologies. Instead of a 'neutral' approach, we offer the analysis of research metaphors underlying the studying of personal epistemologies. Metaphor 'pilgrim's progress' assumes understanding epistemological development as a 'temptation' leading towards 'enlightenment' and abandoning faith in Absolute truth. Metaphor 'regulatory software' narrows down researcher's subject of interest to epistemic cognition in the specific problem situation, whereby evaluation of functioning of 'regulatory software' and its improvement are observed as the most important tasks. Finally, within the metaphor 'decent outfit' the starting assumption is that epistemological beliefs are relatively fixed and that personal epistemologies which are 'balanced' and 'decent' are privileged. By analyzing research metaphors, light was shed on basic assumptions and implications of research of personal epistemologies. The following questions were explored: which ways of 'seeing' were pledged in the approaches to research of personal epistemologies, which methodological choices arise from those ways of 'seeing', as well as which are the functions or effects of different ways of 'seeing'. In this way, a new perspective was offered for the assessment of multiple conceptualizations in research of personal epistemologies.
Education of parents and attitude towards school of their daughters and sons
Authors: Polovina Nada
Published: August 2009

This paper presents the results of the research the goal of which was to gain insight into the linkage between the attitude towards school and educational aspirations of female and male pupils and the aspects of their family environment which are gender marked (educational status of mothers and educational status of fathers as gender-role indicators). The approach to research topic was developed by relying on ecological systems theory of development (Bronfenbrenner) and social-cognitive theory of gender-role development (Bussey and Bandura). Research comprised a representative sample of 2447 female and male pupils of eighth grade from 36 schools in Serbia, and data were obtained by using answers to the questionnaires referring to some aspects of family and school environment. This is an in-depth analysis of data collected as part of the international study TIMSS 2007. Research findings can be expressed on two levels. The first - female eighth grade pupils, compared to their male peers, have considerably higher educational aspirations, a more positive attitude towards school as learning environment, and in extracurricular everyday life they prefer activities which are encouraged by school contents. The second - educational aspirations of male and female pupils are highly positively correlated with the accomplished educational level of the same gender parent, while attitude towards school and the type of extracurricular activities, both in boys/male pupils and girls/female pupils, stand in higher correlation with the accomplished level of education of the mother.
Educational processes in the family: Linkage between the quality of dyad and triad relations
Authors: Mihic Ivana , Zotovic Marija , Petrovic Jelica , Avic Bojana
Published: August 2009

The goal of the research presented in this paper is to describe the relations between educational styles as dyad and co-parenting relations, as well as triad relations in the family which include processes of upbringing and taking care of the child. The sample comprised families with an adolescent. Data were obtained from 200 respondents, of the average age of 18. Respondents evaluated educational styles of their parents (separately father's, separately mother's) in the Questionnaire for evaluating parenting style, and then also the quality of co-parenting cooperation in their families in the questionnaire Co-parenting relations in the family. The results indicate a significant correlation between the dimensions of parental styles and co-parenting relation. In that process, more prominent is the contribution of affective dimensions of parenting style, and what was also perceived and described are the differences in mutual relations of educational styles and co-parenting cooperation regarding parent's gender. The effects of the evaluated co-parental cooperation on educational behavior of the father are more evident.
Self-perception of teachers' mistakes in instruction
Authors: Avramovic Zoran , Vujacic Milja
Published: August 2009

This paper presents the research the goal of which was to gain an insight into teachers' opinions regarding the mistakes they make during classes and the ways to eliminate those mistakes. The sample comprises 300 primary school teachers and 115 vocational school and grammar school teachers in Serbia. Questionnaire with openended questions was used in the research. The first question required the group of teachers to state the example of one mistake they made during the class, and in the second question they were expected to state how they reacted in order to eliminate the aforementioned mistake. We classified the answers according to the following types of teachers' mistakes: didactic-methodical; expert-cognitive; personal; professional; pedagogical; social-moral. The findings of our research indicate that teachers perceive to a far greater extent the didactic-methodical than social-moral mistakes. It was shown that the greatest number of mistakes arises from the wrong decisions or insufficiently thoughtful decisions of teachers. We also analyzed the ways in which teachers try to eliminate their mistakes.
Comprehension of atypical literary text and scholastic achievement
Authors: Bozin Aurel , Milatovic Vuk
Published: August 2009

With the aim of gaining insight into literary text comprehension and the linkage between that comprehension and scholastic achievement during the first years of schooling, a research was conducted on the sample of 152 third and fourth grade pupils from one urban and one rural school. After having read silently a selected atypical excerpt from one literary text, interviewed pupils filled out the questionnaire constructed for the purposes of this research starting from the 11 categories of text comprehension singled out based on the theory of comprehension and interpretation of literary text and the current curriculum. In the first part of the research we applied the Children's orientation scale by Malka Margalit, and school marks were used as a measurement of scholastic achievement. Research results point out that, among other things, inferring on the basis of what has been read poses the greatest difficulty for third and fourth graders, that is, that almost three quarters of them are not capable of determining the meaning of some representative sentences from that text. In the positive sense, it was established that almost three quarters of them perceive beautiful poetic expressions and about 80% of them can at least to a certain extent recognize character descriptions, emotional situations and moods, that is, discover significant facts. Answers to the questions regarding the majority of categories of text comprehension are significantly correlated with scholastic achievement. As expected, the highest correlations between the measures on text comprehension categories are with the marks in native (Serbian) language. Partial correlations between the measures on certain categories of text comprehension and measurements of scholastic achievement (excluding the influence of feeling of coherence) are not significantly different from bivariate. Based on the obtained data, authors conclude that the utilized system of categories can be a useful tool for analyzing literary text comprehension at younger primary school age, that is, that separate observation of comprehension of (atypical) literary text can contribute to gaining a better insight into determinates of development of scholastic achievement.
Students' communicative competence
Authors: Safranj Jelisaveta
Published: August 2009

Communicative competence is the ability to send messages which promote attainment of goals while maintaining social acceptability. Competent communicators attempt to align themselves with each others goals and methods to produce a smooth, productive and often enjoyable dialogue. The aim of this research was to investigate self-perceived communicative competence (SPCC) of students of Engineering Management in General English and English for Specific Purposes (ESP). A longitudinal study was carried out starting with the first year students at the Faculty of Technical Sciences in Novi Sad and was repeated with the same sample of students during their second and third year of study. Participation was voluntary and took place during regular class time. The measure of communicative competence employed was the Self-perceived Communication Competence Scale. The results of the study indicated that differences in SPCC between the years do exist. The SPCC gradually improved between the first, the second and the third year. The research was also motivated by gaining better overview of the teaching activity. An anonymous questionnaire provided many useful hints and ideas for further work and thus, language teacher made a thorough analysis of the overall teaching procedure. However, it is essential to get some feedback and talk to students in order to evaluate both them and ourselves as well as the teaching syllabus.
Pupils' involvement in ecological activities in school
Authors: Stanisic Jelena
Published: August 2009

Ecological education gains an increasing importance in the moment when ecological crisis acquires increasingly larger proportions. Education is one of the most powerful social means in fighting problems and challenges of the future. This paper presents the results of the research referring to pupils' attitudes with respect to the activities they prefer to be involved in, the independent variables their readiness for involvement depends on, as well as the relation between the knowledge possessed by pupils and their readiness to be involved in ecological activities. Research was conducted on the sample of 284 pupils in the eighth grade of primary school in urban and rural area and polluted and unpolluted environment. The results indicate that pupils find more interesting the activities taking place in nature, those where they are immediate participants and those where they have a subjective feeling that they are doing something to protect the environment. Besides, the results show that girls from both samples and pupils from rural area are more ready to get involved in ecological activities. Living in polluted or unpolluted environment is not a statistically significant variable which would influence the readiness of pupils to get involved in these activities. As the most interesting result of this research, we consider the finding that a higher level of pupils' ecological knowledge and living in polluted environment do not guarantee higher readiness of pupils to get involved in the activities of environment protection.
Assessing the Contribution of Distributed Leadership to School Improvement and Growth in Math Achievement
Authors: Heck Ronald H. , Hallinger Philip
Published: August 2009

Although there has been sizable growth in the number of empirical studies of shared forms of leadership over the past decade, the bulk of this research has been descriptive. Relatively few published studies have investigated the impact of shared leadership on school improvement. This longitudinal study examines the effects of distributed leadership on school improvement and growth in student math achievement in 195 elementary schools in one state over a 4-year period. Using multilevel latent change analysis, the research found significant direct effects of distributed leadership on change in the schools’ academic capacity and indirect effects on student growth rates in math. The study supports a perspective on distributed leadership that aims at building the academic capacity of schools as a means of improving student learning outcomes.
National Income, Income Inequality, and the Importance of Schools: A Hierarchical Cross-National Comparison
Authors: Chudgar Amita , Luschei Thomas F.
Published: August 2009

The international and comparative education literature is not in agreement over the role of schools in student learning. The authors reexamine this debate across 25 diverse countries participating in the fourth-grade application of the 2003 Trends in International Mathematics and Science Study. The authors find the following: (a) In most cases, family background is more important than schools in understanding variations in student performance; (b) schools are nonetheless a significant source of variation in student performance, especially in poor and unequal countries; (c) in some cases, schools may bridge the achievement gap between high and low socioeconomic status children. However, schools’ ability to do so is not systematically related to a country’s economic or inequality status.
Is There an Expectations Gap? Educational Federalism and the Demographic Distribution of Proficiency Cut Scores
Authors: Reed Douglas S.
Published: August 2009

Recent analyses of state-level proficiency standards under No Child Left Behind indicate that states’ benchmarks for determining whether a child is proficient in reading and math are widely divergent. This article explores whether the capacity of states to employ different proficiency standards imposes different performance standards across demographic groups. Using a newly devised metric that allows for interstate comparison of state-level proficiency cut scores, along with aggregated district-level demographic data, this article provides a descriptive analysis of the distribution of proficiency standards across demographic groups to determine whether some groups systematically face higher or lower proficiency cut scores. The findings indicate that while an “expectations gap” does exist, it does not operate consistently across categories of race, ethnicity, and poverty status. The article concludes by reviewing the trade-offs required under three possible policy responses to these findings.
Humidity influence on the adhesion of biomimetic fibrillar surfaces
Authors: Buhl Sebastian , Greiner Christian , Campo Aránzazu del , Arzt Eduard
Published: August 2009

The recent interest in fibrillar biological attachment systems, as found in the gecko, has led to the development of micropatterned elastomer adhesion surfaces. All reported studies have been performed at ambient humidity neglecting its possible influence on adhesion. The present paper investigates, for the first time, the effect of systematic changes in ambient humidity from 2 to 90 %. Adhesion measurements were performed on PDMS (Sylgard 184) surfaces possessing micropillars with flat-ended and hemispherical contact shape. The pillar radius was varied between 2.5 and 25 μm; the pillar aspect ratio was kept at 1. While the adhesion of a flat sample was not affected by humidity, we found that pillar size and shape influenced the sensitivity to humidity changes: Thinner pillars, with higher pull-off forces in the dry state, exhibited decreasing adhesion values, by up to 35 %, with increasing humidity. The effect was stronger for the hemispherical tip shape, where the positive effect of finer pillars was even reversed. Possible explanations for these effects, which may lower the reliability of biomimetic adhesion devices in the presence of humidity, are given.
Characterization and properties of NiTi(W) and CuAlNi shape memory alloys
Authors: Kneissl A. C. , Mehrabi K. , Bruncko M. , McKay B. J. , Uhlenhaut D.
Published: August 2009

Shape memory wires were trained under constant stress in order to introduce a uniaxial shape memory effect by a thermomechanical treatment. These investigations were carried out on three different alloy systems (NiTi, NiTiW and CuAlNi) with different microstructures (cold-worked and annealed condition, with and without particles, large and small grain size). Several thousand thermal cycles were performed on the trained shape memory elements, continuously observing the changes in the deformation behaviour. The influence of the microstructure on development and stability of the intrinsic two-way shape memory effect has been discussed. Furthermore, this work deals with the production of thin specimens of shape memory alloys by melt-spinning and splat-cooling, the training procedure and their characterization with respect to microstructure and functional properties.
Overview on established and novel FIB based miniaturized mechanical testing using in-situ SEM
Authors: Kiener Daniel , Motz Christian , Dehm Gerhard , Pippan Reinhard
Published: August 2009

Probing mechanical properties in the micrometer regime is of current interest in materials science. A focused ion beam microscope was employed to fabricate miniaturized specimens, while an indenter installed in a scanning electron microscope was utilized to actuate the samples and record the load and displacement data during the deformation. Examples for miniaturized compression, tension, bending, as well as newly developed bending fatigue and bending fracture experiments are presented, demonstrating the unique flexibility of in-situ mechanical testing in the scanning electron microscope at small length scales.
Thermal stability of high-speed steels as characterized by X-ray diffraction profile analysis
Authors: Leitner H. , Clemens H.
Published: August 2009

In practice the thermal stability of high-speed steels is assessed by simple hardness tests. As high-speed steels can be seen as a composite material of a particle-strengthened metallic matrix and coarse primary carbides, the measured hardness is a mixture of both microstructural constituents. Whereas the primary carbides do not change during tempering, the particle-strengthened matrix is prone to microstructural changes, thus affecting the mechanical properties. Consequently, characterization methods which are sensitive only to the matrix have to be applied. In this study single-peak profile analysis were carried out to investigate the thermal stability of high-speed steel matrices. By applying this method the lattice distortion was obtained and compared to classical hardness tests. In a first step, the applicability of this method was investigated. Afterwards, four different high-speed steels were analyzed. The investigations showed that the distortion of the lattice of the matrix depends on their microstructure and composition, which both depend on the heat treatment history. The observed differences in hardness can be correlated to differences in lattice distortion of the matrix and the present amount of primary carbides.
Recrystallization and grain growth in the nickel-based superalloy allvac 718Plus
Authors: Sommitsch Christof , Huber Daniel , Ingelman-Sundberg Fredrik , Mitsche Stefan , Stockinger Martin , Buchmayr Bruno
Published: August 2009

The nickel-based superalloy Allvac 718Plus was developed in order to combine formability and cost advantages of Alloy 718 with high temperature strength of Alloy 720. Typical applications for this new material are turbine disks that are produced by closed die forging, e. g. by screw pressing. The final mechanical properties are strongly related to the microstructure, which forms during hot forming. It is therefore of great interest to model both the dynamic and static grain structure development during processing. In this work, dynamic and static recrystallization as well as normal grain growth models are described for this material. The calculated grain structure evolution in Allvac 718Plus is compared to that of Alloy 718 in the typical process range of disk forging. Additionally, both the experimental program and structure analysis methodology are specified.
On the role of eutectics during recrystallization in a single crystal nickel-base superalloy – CMSX-4
Authors: Wang Li , Pyczak Florian , Zhang Jian , Singer Robert F.
Published: August 2009

The role of eutectics in recrystallization in a single crystal nickel-base superalloy – CMSX-4 – was studied by electron backscatter diffraction and electron probe micro-analysis techniques. It was shown that eutectics can initiate recrystallization by a particle stimulated nucleation mechanism which operates in interdendritic regions. During grain growth in the course of recrystallization, eutectics were observed to inhibit the motion of the advancing recrystallization grain boundary. Alternatively, a recrystallization grain boundary can migrate through eutectics by forming a large ′ phase particle behind the advancing front, either with the same crystal orientation as the eutectic the boundary advances into or, in some cases, with completely new orientations, i. e. neither the same as the eutectic it grows into nor the same as the recrystallized grains surrounding it.
Short-term creep behavior of a Cr Mo V hot-work tool steel
Authors: Wurmbauer Harald , Leitner Harald , Panzenböck Michael , Scheu Christina , Clemens Helmut
Published: August 2009

Hot-work tool steels are used for die casting, extrusion molding and drop forging tools and thus are exposed to high temperatures and elevated stresses during application. To get insight into the materials' behavior under those conditions, short-term creep tests are performed at temperatures in the range of 550 – 590 °C and at stress levels ranging from 400 – 750 MPa. A steady-state creep range is not observed. Instead only a minimum strain rate appears. This minimum is followed by an extended tertiary creep range. Based on the observed stress exponent at 590 °C recovery-controlled dislocation creep has been identified as the dominant creep mechanism. During creep carbide coarsening, recovery and recrystallization occur, as observed by scanning electron microscopy and transmission electron microscopy.
Design strategy for new biodegradable Mg–Y–Zn alloys for medical applications
Authors: Hänzi Anja C. , Sologubenko Alla S. , Uggowitzer Peter J.
Published: August 2009

The aim of this article is to describe the design strategy deployed in developing new biodegradable Mg–Y–Zn alloys. The development approach is based on a microalloying concept which aims to restrict grain growth considerably during alloy casting and forming. We discuss the efficiency of the design approach, and evaluate the characteristics of the new alloys using metal-physical experiments, thermodynamic calculations and transmission electron microscopy analysis. Our results show that after extrusion the alloys have very fine grains (< 10 m), exhibit high ductility (uniform elongation: 17 – 20 %) at considerable strength (ultimate tensile strength: 250 – 270 MPa) and reveal the presence of finely distributed intermetallic particles which are stable upon annealing. Due to an attractive combination of mechanical, electrochemical and biological properties, the new alloys are very promising not only for applications in medicine but also in other fields.
Influence of deposition conditions on texture development and mechanical properties of TiN coatings
Authors: Mayrhofer Paul H. , Geier Markus , Löcker Christian , Chen Li
Published: August 2009

The influence of varying substrate temperature, N2 partial pressure, ion energy, and ion-to-Ti flux ratio on the texture development and mechanical properties of TiN is investigated in detail. We show that during low substrate temperature (T
s
= 300 °C) reactive sputtering of TiN in a mixed Ar + N2 discharge a change from 111- to 001-oriented growth occurs when increasing the ion-to-Ti ratio J
i/J
Ti above 2.5 while using a low ion energy E
i of 30 eV. This texture change can be reversed to a 111-oriented growth by increasing the ion energy to 60 and 90 eV when using high ion-to-Ti ratios J
i/J
Ti of 2.5 and 9, without introducing strain. Thereby the hardness can be increased from ∼31 to 37 GPa with only minor changes in compressive stresses. Consequently, by defining the ion-to-Ti ratio and the ion energy during low substrate temperature reactive sputtering of TiN the texture development towards 111- or 001-oriented growth can be controlled. Based on previous studies and the texture development as a function of substrate temperature and N2-partial pressure, we propose that varying the ion-to-Ti ratio and the ion energy result in different N-terminated surfaces and hence different Ti-fluxes from 111- to 001-oriented grains and vice versa.
Outcome and Prognosis of Metastatic Brain Tumour: A Study of 35 Cases
Authors: Nath Haradhan Deb , Barua Kanak Kanti , Hossain Mohammad Afzal , Khair Md Abul , Islam Md Aminul
Published: August 2009

Thirty five patients were selected to evaluate the outcome & prognosis of metastatic brain tumour in the department of Neurosurgery, Bangabandhu Sheikh Mujib Medical University, (BSMMU) Dhaka from February 2002 to December 2005. A structured questionnaire was made. Data were collected after the patient admission. All patients were evaluated with detailed history and clinical examination. MRI of Brain of these patients revealed intracranial lesions highly suspicious of metastatic brain tumour. Investigations like USG of the whole abdomen and x-ray chest were done to locate any primary site. Some of the primary lesions were confirmed by FNAC and histological examinations. Solitary intracranial space occupaing lesion (ICSOL) and sizable lesion among the multiple lesions were treated by surgery, and then histopathological examination were done followed by radiotherapy and / or chemotherapy. This was a prospective study. This study showed the highest age of incidence of tumours were above 60 years. Male predominated than female (60.00%). Among the clinical features the most common sign was hemiparesis (34.28%). The commonest site of lesion was in frontal region (34.28%). Histopathological reports showed adenocarcinoma 40.00%, small cell carcinoma of lungs 28.57%, squamous cell carcinoma 22.85%, follicular carcinoma of thyroid 5.71%. Treatment options were surgery, radiotherapy and chemotherapy. Sixty percent patients were improved after treatment. Highest survival rate was 3 to 6 months with treatment (31.42%). This study revealed that commonest type of brain metastases was adenocarcinoma and primary site of lesion was lungs. Best option of treatment was surgery plus radiotherapy and longest survival rate of 1 year was in 20.00% cases. DOI: http://dx.doi.org/10.3329/bjn.v24i1.3036 Bangladesh Journal of Neuroscience 2008; Vol. 24 (1) : 17-23
Blood Pressure Profile in Post-Stroke Patients
Authors: Jahan Sehelly , Alam Md Tarek , Masud Zafor Md , Ali Zahed
Published: August 2009

Blood pressure profile after ischemic stroke in both hypertensive and non-hypertensive patients usually follows a benign course. This prospective study was done among the admitted patients in Bangladesh medical college, starting from November 2006 to August 2007. We observed 80 cases where there was sharp rise of blood pressure in most cases in the early part of ischemic stroke which gradually came down to its previous level within 7-10 days, without any antihypertensive drug. These patients were specially selected as they had only ischemic stroke with or without hypertension. Patients having comorbidities other than diabetes were excluded. DOI: http://dx.doi.org/10.3329/bjn.v24i1.3040 Bangladesh Journal of Neuroscience 2008; Vol. 24 (1) : 45-49
Intrauterine Exposure to Arsenic Affect Infant Development
Authors: Tofail Fahmida , Hamadani Janna D , Hakim Maliha , Ali Zahed , Ahmed AZ Tofail
Published: August 2009

The ICDDR,B Child Development Unit (CDU) conducted a longitudinal observational study on a sample of 1562 pregnant mothers in Matlab, Bangladesh, to examine the intrauterine effects of arsenic on infants. Drinking water consumed by the mothers during their pregnancy was assessed for arsenic concentration using atomic-absorption spectroscopy. Infants were assessed for cognitive and psychomotor development at the age of 7 months. Sixty-three percent of all functioning tube wells had arsenic contamination above 50?g/L. Infants whose mother drank water from wells with >50?g/ L of arsenic had slightly lower developmental scores than those whose mother's drinking water had lower arsenic levels. While the clinical importance and long-term implications of these developmental differences need to be determined, these results provide further evidence of the urgent need to reduce the arsenic contamination in Bangladesh. DOI: http://dx.doi.org/10.3329/bjn.v24i1.3042 Bangladesh Journal of Neuroscience 2008; Vol. 24 (1) :55-59
Tuberous Sclerosis- A Rare Cause of Seizure
Authors: Mondol Md Badrul Alam , Siddiqui Md Mahmudur Rahman , Hussain Md Enayet
Published: August 2009

Tuberous sclerosis (TS) is one of the important neurocutaneous syndrome with a variety of clinical manifestations. We present a 19 years old boy with classical triad of Tuberous sclerosis who had seizure, mental retardation, facial angiofibromas and also having other features which cover the newer diagnostic criteria's. TS should be considered as a differential diagnosis in patient of seizure with mental retardation. DOI: http://dx.doi.org/10.3329/bjn.v24i1.3043 Bangladesh Journal of Neuroscience 2008; Vol. 24 (1) : 60-63
Management of Sepsis-Induced Acute Kidney Injury
Authors: Rajapakse Senaka , Rodrigo Chaturaka , Wijewickrema Eranga S.
Published: August 2009

Acute kidney injury (AKI) occurs in a significant proportion of patients with severe sepsis, and is an important cause of mortality in such patients. Current concepts of pathogenesis of AKI are shifting from vasoconstriction-ischaemia induced injury to toxic and immune mediated injury and hyperaemic injury resulting in apoptosis of renal cells.  Renal replacement therapy is the mainstay of management of AKI. Adequacy of dialysis is likely to be linked to better outcome, but there is still no clear consensus on the timing, modality, intensity or frequency of dialysis. Haemodynamically unstable patients usually require modes of continuous renal replacement therapy. Biocompatible dialyser membranes are likely to be safer than older cellulose membranes. Bicarbonate is preferred to acetate and lactate as dialysate buffer.  Anticoagulation has to be undertaken with care to prevent excessive haemorrhage in the setting of already deranged  haemostasis.  Adequate volume resuscitation and maintenance of renal perfusion by the use of vasopressors is beneficial; norepinephrine is the vasopressor of choice. There is no place for the use of low- or renal-dose dopamine, mannitol or frusemide in the setting of sepsis-induced AKI, and in fact they may be detrimental. Prevention of kidney damage by nephrotoxic drugs and radio-contrast media is of vital importance. Careful dose management of nephrotoxic drugs will prevent renal injury. Hydration prior to administration of contrast media prevents nephrotoxicity, but the benefit of N-Acetylcysteine is unclear. Tight glycaemic control may have renoprotective effects, though its place in the management of severe sepsis is now controversial. No clear evidence of benefit is seen with other newer therapies.Keywords: Critical care; acute kidney injury; dialysis; renal replacementCitation: Rajapakse S, Rodrigo C, Wijewickrema ES. Management of Sepsis-Induced Acute Kidney Injury. Sri Lanka Journal of Critical Care 2009;1:3-14DOI: 10.4038/sljcc.v1i1.937