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Different Problems (different + problem)
Selected AbstractsDirect use of vegetable oil and animal fat as alternative fuel in internal combustion engineBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 2 2008Pinaki Mondal Abstract Gradual depletion of world petroleum reserves and the impact of environmental pollution of increasing exhaust emissions lead to the search for a suitable alternative fuels for diesel engines. The substitution of conventional fuels (gasoline, diesel) by renewable biofuels is considered a potential way to reduce pollution and to support the sustainable development of a country. Direct use of vegetable oil and animal fat is a promising alternative to solve these problems. An exhaustive review of the experiments in this area, carried out by several researchers in last three decades, is presented here. Different problems associated with the direct use of vegetable oil and animal fat and potential solutions from both public and private sectors are discussed. Some engine manufacturers have started to launch full-warranty engines with vegetable oil as fuel. It is expected that the competitive engine market will witness more intense research, resulting in the launch of more vegetable-oil engines with full warranties. The steep rise in food prices in recent years is concerning policy-makers and has raised the old ,food vs fuel' debate. It has been concluded that vegetable oil can probably only substitute small to medium portions of petroleum-based fuel due to future severe land-usage competition from food sector. This calls for intense research initiatives into the production of suitable fuel from non-edible vegetable oil, grown in wasteland. In this regard, genetic engineering may prove to be extremely effective in developing ,designer fuel'. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd [source] Providing support for problem-based learning in dentistry: the Manchester experienceEUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 1 2003Gillian Hoad-Reddick The introduction of problem-based learning (PBL) into any programme demands a period of adjustment on the part of faculty. Similarly, students new to PBL take time to adapt to what is, for the majority of them, an unfamiliar mode of learning. At Manchester, closed loop PBL is used throughout the first and second years of the dental programme; the method is interdisciplinary; there are no subject boundaries. Dental students work in groups of between 10 and 15, facilitated by a tutor from the Department of Biological Sciences, to research topics and share information in a mutually supportive environment. Each week a different problem forms the focus for learning. In this paper, we seek to describe the measures introduced in response to student feedback collected via routine meetings with the senior tutor, after meetings with their academic or personal tutors and through discussion at the staff students' committee, which we at Manchester have taken to facilitate the process of adaptation to PBL. Changes have been made in the areas of recruitment, pre-admission interviewing, induction (development of an induction booklet and communication skills module) and tutorial support (overhaul of personal tutor system and introduction of peer-assisted study (PAS) and personal and academic development programmes (PADPs)). Feedback on these changes, gathered via the routes described above, has been positive and continues to be central to our processes of development in these areas. Although the various ways in which PBL has been implemented worldwide may place limits on the transferability of our methods, this paper serves to illustrate some of the means available to support students in the transition to self-directed learning. The latter is not only an essential component of PBL but also something we should be seeking to foster in all students, no matter what philosophy and method of course delivery are utilized. [source] Modified methodology for computing interference in LEO satellite environmentsINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 6 2003Raúl Chávez Santiago Abstract Computing interference is very important in satellite networks design in order to assure the electromagnetic compatibility (EMC) with other radiocommunication systems. There are different methods to compute interference in geostationary (GEO) satellite systems including conventional methods using link budget equations and alternate methods such as increase in noise temperature. However, computing interference in low earth orbit (LEO) systems represents a different problem. Due to the special characteristics of this kind of orbits, the elevation angle at any site changes continuously over time, meaning a time dependent change of the propagation path length between an interfering transmitter and an interfered-with receiver, and of the discrimination provided by the transmitting and/or the receiving antenna. Thus, conventional interference prediction methods developed for fixed links must be adapted to the case of LEO systems. To overcome this problem a mathematical model that characterizes the path length variations by an average value obtained from the probability density function of the varying distance between an interfering transmitter and an interfered- with receiver is proposed in this paper. This average path length enables the use of conventional link budget methods to reduce the computation time for the evaluation of interference in LEO satellite environments. Two practical examples show the possible applications of the proposed model. Copyright © 2003 John Wiley & Sons, Ltd. [source] Relapse prevention with sex offenders: practice, theory and researchCRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 1 2001Gilles Launay Head of Psychology Introduction Relapse prevention (RP) is now applied to sex offending. It has been questioned as to whether RP is worthwhile. This paper aims to evaluate this technique. The Rochester RP programme The purpose of the Rochester RP programme is to refine and strengthen skills gained in the prison department's sex offender treatment programme. The objective of the programme is to teach prisoners to recognize the chain of events leading up to their current offences and to practise strategies to interrupt this chain. Theoretical basis for RP Stopping an undesired behaviour and maintaining abstinence are two different problems. RP aims to address the maintenance problems. At the centre of RP theory is a study of the conditions that can turn lapse into relapse. Yet RP has been criticized as a lot of jargon saying very little. Ward and Hudson criticize RP constructs and their interaction. Such debates have few implications for clinical work and most of the criticism flies in the face of clinical experience. Research basis for RP Risk factors for sex offenders are being identified. Local evaluation of the Rochester programme suggests that prisoners do learn to identify risk factors and to develop coping strategies. As yet, however, there is no evidence as to whether RP works or not. Discussion A way to improve the efficacy of an RP programme may be to augment it with additional modules, e.g. behaviour therapy, drug treatment, continued work with the same prison staff and relaxation training. Conclusion RP theory is sound in essence but suffers from an overlay of cumbersome vocabulary. Reliable research is emerging. Copyright © 2001 Whurr Publishers Ltd. [source] Distortions of EM transients in coincident loops at short time-delaysGEOPHYSICAL PROSPECTING, Issue 6 2000F. Kamenetsky Transient electromagnetic measurements with short time-delays of transients are used for solving different problems within the upper part of a geoelectric section. However, it is necessary to take into consideration distortions connected with self-transients within the transmitter,receiver system. From the practical point of view, it is important to estimate the minimum time-delay after which these distortions may be neglected. We present such an estimation which uses a simple approximation method for a single-loop (or coincident-loop) configuration. For common values of the loop size (10 m × 10 m to 40 m × 40 m) and of the resistivity of a homogeneous half-space (1,100 ,m), the minimum time-delay beyond which we can use a standard interpretation is in the range of 2,10 µs. This is equivalent to a minimum depth of investigation in the range of 1,30 m. [source] The lifespan and life-cycle of self-help groups: a retrospective study of groups in Nottingham, UKHEALTH & SOCIAL CARE IN THE COMMUNITY, Issue 4 2010Sarah Chaudhary LLB (Hons) MA Abstract This article is based on an analysis of a practice database held by Self Help Nottingham, an organisation that supports local self-help groups. The database contains details of 936 groups that closed between 1982 and 2007. The aim of the study is to provide qualitative and descriptive quantitative information about the life-cycles of self-help groups, the problems that they face throughout their existence and the likelihood of different problems leading to their closure. The database was not collated for research purposes and so we restrict our discussion of the findings to identification of broad patterns regarding the birth and closure rates of different types of group and questions for future research. Comparisons were made between groups that addressed different types of problem, groups with different memberships and groups that had reached different stages in their existence. There was reasonable consistency in the survival rates of different types of group with physical health groups being the most likely to reach maturity followed by mental health and lastly social issue groups. Survival rates for groups that serve different membership populations were reasonably constant although there were some anomalies. There were high levels of consistency regarding the reasons for closure for groups closing at different stages of maturity. The most commonly cited reasons among all groups were the withdrawal of a ,key' member and a decline in membership. The article suggests that some of the assumptions and prescriptions within the existing literature need to be considered in light of more detailed empirical evidence, and it raises questions about the theoretical understanding of self-help groups. [source] An adaptive stabilization strategy for enhanced strain methods in non-linear elasticityINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 11 2010Alex Ten Eyck Abstract This paper proposes and analyzes an adaptive stabilization strategy for enhanced strain (ES) methods applied to quasistatic non-linear elasticity problems. The approach is formulated for any type of enhancements or material models, and it is distinguished by the fact that the stabilization term is solution dependent. The stabilization strategy is first constructed for general linearized elasticity problems, and then extended to the non-linear elastic regime via an incremental variational principle. A heuristic choice of the stabilization parameters is proposed, which in the numerical examples proved to provide stable approximations for a large range of deformations, different problems and material models. We also provide explicit lower bounds for the stabilization parameters that guarantee that the method will be stable. These are not advocated, since they are generally larger than the ones based on heuristics, and hence prone to deteriorate the locking-free behavior of ES methods. Numerical examples with two different non-linear elastic models in thin geometries and incompressible situations show that the method remains stable and locking free over a large range of deformations. Finally, the method is strongly based on earlier developments for discontinuous Galerkin methods, and hence throughout the paper we offer a perspective about the similarities between the two. Copyright © 2009 John Wiley & Sons, Ltd. [source] On solving large strain hyperelastic problems with the natural element methodINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 2 2005B. Calvo Abstract In this paper, an extension of the natural element method (NEM) is presented to solve finite deformation problems. Since NEM is a meshless method, its implementation does not require an explicit connectivity definition. Consequently, it is quite adequate to simulate large strain problems with important mesh distortions, reducing the need for remeshing and projection of results (extremely important in three-dimensional problems). NEM has important advantages over other meshless methods, such as the interpolant character of its shape functions and the ability of exactly reproducing essential boundary conditions along convex boundaries. The ,-NEM extension generalizes this behaviour to non-convex boundaries. A total Lagrangian formulation has been employed to solve different problems with large strains, considering hyperelastic behaviour. Several examples are presented in two and three dimensions, comparing the results with the ones of the finite element method. NEM performs better showing its important capabilities in this kind of applications. Copyright © 2004 John Wiley & Sons, Ltd. [source] A three-dimensional contact algorithm for sliding surfacesINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 11 2003A. S. Dawes This paper describes a model for sliding contact between materials. This has been embodied in a contact algorithm which has been incorporated into a three-dimensional, time-dependent, staggered mesh, finite element Lagrangian code. We first present an overview of the code and then describe the model underpinning the contact algorithm. The stages of the algorithm are then described and finally, results are presented for a number of different problems. Copyright © 2003 John Wiley & Sons, Ltd. [source] Vortex surface method: some numerical problems of the potential calculationINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 8 2001T. Belamri Abstract The singularities method is used to analyze the flow around an isolated profile or through a plane cascade. In this paper, a numerical study has been developed in order to discuss the accuracy of solutions. The aims of this study are summarized as follows: (1) to expose the elements that influence the method,precision in the geometrical profile definition, trailing-edge geometry, smoothing problems, number of discretization points, precision of calculation, etc.; (2) to provide an accurate solution for these different problems. For example, some profiles, obtained by the Joukowski transformation, present, in spite of an analytical definition, a crossing of the suction and pressure sides at the trailing edge. This crossing causes a serious error in the velocity field computation. A new procedure to solve this problem is presented. Copyright © 2001 John Wiley & Sons, Ltd. [source] Joint power, subcarrier and subframe allocation in Multihop relay networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 7 2009Tolga Girici Abstract In this paper we study the problem of subframe, subchannel and power allocation in OFDMA-based multihop relay networks. The system consists of a base station (BS), a number of relay stations (RS) and mobile stations (MS). We consider frame by frame scheduling, where the frame is divided into two subframes such as BS-RS and RS-MS subframes. We study two different problems, satisfying link rate requirements with minimum-weighted total power and maximizing proportional fairness. For the first problem, we find the optimal solution and also propose a less complex subframe and bandwidth allocation scheme with good performance. For the second problem, we propose an algorithm that outperforms an existing scheme with less feedback. Copyright © 2009 John Wiley & Sons, Ltd. [source] Underwater archaeological surveying using PhotoModeler, VirtualMapper: different applications for different problemsINTERNATIONAL JOURNAL OF NAUTICAL ARCHAEOLOGY, Issue 2 2002Jeremy Green Techniques of underwater photogrammetry discussed include accuracy measurements and survey techniques. [source] Reliable computing in estimation of variance componentsJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 6 2008I. Misztal Summary The purpose of this study is to present guidelines in selection of statistical and computing algorithms for variance components estimation when computing involves software packages. For this purpose two major methods are to be considered: residual maximal likelihood (REML) and Bayesian via Gibbs sampling. Expectation-Maximization (EM) REML is regarded as a very stable algorithm that is able to converge when covariance matrices are close to singular, however it is slow. However, convergence problems can occur with random regression models, especially if the starting values are much lower than those at convergence. Average Information (AI) REML is much faster for common problems but it relies on heuristics for convergence, and it may be very slow or even diverge for complex models. REML algorithms for general models become unstable with larger number of traits. REML by canonical transformation is stable in such cases but can support only a limited class of models. In general, REML algorithms are difficult to program. Bayesian methods via Gibbs sampling are much easier to program than REML, especially for complex models, and they can support much larger datasets; however, the termination criterion can be hard to determine, and the quality of estimates depends on a number of details. Computing speed varies with computing optimizations, with which some large data sets and complex models can be supported in a reasonable time; however, optimizations increase complexity of programming and restrict the types of models applicable. Several examples from past research are discussed to illustrate the fact that different problems required different methods. [source] Outcomes of the International Union of Crystallography Commission on Powder Diffraction Round Robin on Quantitative Phase Analysis: samples 2, 3, 4, synthetic bauxite, natural granodiorite and pharmaceuticalsJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2002Nicola V. Y. Scarlett The International Union of Crystallography (IUCr) Commission on Powder Diffraction (CPD) has sponsored a round robin on the determination of quantitative phase abundance from diffraction data. The aims of the round robin have been detailed by Madsen et al. [J. Appl. Cryst. (2001), 34, 409,426]. In summary, they were (i) to document the methods and strategies commonly employed in quantitative phases analysis (QPA), especially those involving powder diffraction, (ii) to assess levels of accuracy, precision and lower limits of detection, (iii) to identify specific problem areas and develop practical solutions, (iv) to formulate recommended procedures for QPA using diffraction data, and (v) to create a standard set of samples for future reference. The first paper (Madsen et al., 2001) covered the results of sample 1 (a simple three-phase mixture of corundum, fluorite and zincite). The remaining samples used in the round robin covered a wide range of analytical complexity, and presented a series of different problems to the analysts. These problems included preferred orientation (sample 2), the analysis of amorphous content (sample 3), microabsorption (sample 4), complex synthetic and natural mineral suites, along with pharmaceutical mixtures with and without an amorphous component. This paper forms the second part of the round-robin study and reports the results of samples 2 (corundum, fluorite, zincite, brucite), 3 (corundum, fluorite, zincite, silica flour) and 4 (corundum, magnetite, zircon), synthetic bauxite, natural granodiorite and the synthetic pharmaceutical mixtures (mannitol, nizatidine, valine, sucrose, starch). The outcomes of this second part of the round robin support the findings of the initial study. The presence of increased analytical problems within these samples has only served to exacerbate the difficulties experienced by many operators with the sample 1 suite. The major difficulties are caused by lack of operator expertise, which becomes more apparent with these more complex samples. Some of these samples also introduced the requirement for skill and judgement in sample preparation techniques. This second part of the round robin concluded that the greatest physical obstacle to accurate QPA for X-ray based methods is the presence of absorption contrast between phases (microabsorption), which may prove to be insurmountable in some circumstances. [source] The Challenge of asthma in adolescencePEDIATRIC PULMONOLOGY, Issue 8 2007Diletta de Benedictis MD Abstract The adolescents with asthma are a distinct group of patients with different problems and needs compared to children and adults. Specific issues of asthma in adolescence are the variability of the clinical spectrum, the presence of particular risk factors for the persistence of symptoms, underdiagnosis and undertreatment of the disease. Refusal of the sick role, denial of symptoms, carelessness about dangerous inhalation exposure, erratic self-medication, overexertion without taking precautions against exercise-induced asthma, and a poor relationship between patients, their families, and often doctors are the main obstacles to successful management of asthma in this critical age. There are also major problems of compliance for these patients. The goal of optimal quality of life will be achieved only if the physician thoroughly understands the adolescent's needs and provides optimal care. Pediatr Pulmonol. 2007, 42:683,692. © 2007 Wiley-Liss, Inc. [source] Generalized Public Health and Industrial Nurses Work TogetherPUBLIC HEALTH NURSING, Issue 4 2009Margaret A. Schwem ABSTRACT Occupational health has been considered a subset of public health nursing for years. The first industrial or occupational health nurses were employed by large companies in the 1890s but the role evolved quickly in the early 20th century. By mid-century, many large companies employed a physician and nurse(s) to provide examinations, screenings, episodic care, and trauma intervention for workers. Occupational health nurses faced different problems than community-based public health nurses in generalized nursing service. The intersection of public health and employee health was apparent, though, because large industries often constituted the main workplace for a smaller community and sickness could spread throughout a town if the occupational health nurse was not well-prepared in principles of infection control and health promotion. Excerpts from this July 1949 article about building relationship between public health and industrial nurses illustrate the benefits hoped for when they were formally connected to one another through cross-training and in-service education. The author, Margaret Schwem, was a supervisor at the Rensselaer County Department of Health in Troy, New York. In the original article, Schwem included a list of reference materials for those interested in public health and industrial nursing. [source] Validation of the gastrointestinal quality of life index for patients with potentially operable periampullary carcinomaBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 1 2000Dr E. J. M. Nieveen van Dijkum Background: A disease-specific quality of life questionnaire is not available for patients with periampullary carcinoma, although cancer-specific questionnaires and the Gastrointestinal Quality of Life Index (GIQLI) have been used. The aim of this study was to validate the GIQLI for patients with periampullary tumours and to evaluate if subscales of the GIQLI could be identified to allow a more detailed assessment of the patients' quality of life. Methods: Patients with periampullary carcinoma, included in a study concerning diagnostic laparoscopy, were asked about symptoms and completed a questionnaire comprising the Medical Outcomes Study (MOS) 24 questionnaire, the GIQLI and one question of the Rotterdam Symptom Check List (RSCL). Clinical interpretation and statistical factor analysis were used to identify subscales of the GIQLI. Results: The GIQLI could be divided into four subscales, measuring physical well-being, mental well-being, digestion and defaecation. All four subscales had a good internal reliability and the construct validity was supported by the pattern of correlations with the MOS and RSCL as well as differences in subscale scores for patients with or without certain symptoms. Conclusion: In patients with periampullary tumours the GIQLI can be divided into four subscales, measuring different aspects of quality of life. These subscales provide insight into the different problems affecting the patient. © 2000 British Journal of Surgery Society Ltd [source] Use of the Kidcope to identify socio-economically diverse Spanish school-age children's stressors and coping strategiesCHILD: CARE, HEALTH AND DEVELOPMENT, Issue 6 2009N. Pereda Abstract Background The process by which children cope with stressful events is a very relevant topic. However, few systematic efforts have been made to design age-specific measures. Methods This study examined problems commonly experienced by children, ages between 7 and 12 years, from two different sources: a primary school mainly enrolling families of medium socio-economic status, and an after-school social care centre from a socially and economically deprived neighbourhood. Data were obtained using the younger version of the Kidcope. Results Almost 55% of the sample reported a problem related to others with no differences observed in age, gender or school group. The strategies that children considered the most effective were ,social support' (35%), ,emotional regulation' (33%) and ,wishful thinking' (32%). The children from disadvantaged backgrounds reported different problems mainly related with ,victimization and violence', ,moving house' and conflicts with ,norms and rules' and tended to use avoidant strategies to face them, which could be related to the perception of uncontrollability of these stressors. Conclusions This study reported the first descriptive results in the type of problems and coping strategies of two different social groups of Spanish children using the Kidcope. The Kidcope can be useful to screen children for coping abilities at an early age living under stressful conditions in underprivileged sectors of society. [source] | |||||||||||||||||||