Effect of Thermal and Mechanical Deformation of Metamaterial FDM Components

At Lancaster University, research is currently investigating the use of rapid manufacturing (RM) to realise metamaterials, although key to the success of this project is the development of an understanding of how coated RM parts deform under thermal and mechanical stress. The research in this paper presents a comparison of the thermal and mechanical deformation behaviour of RM coated metamaterials components from a numerical context. The research uses the design of a simple metamaterial unit cell as a test model for both the experimental and finite element method (FEM). The investigation of deformation behaviour of sample Fused Deposition Modelling (FDM) parts manufactured in different orientations and simulated using commercial FEM code means that the FEM analysis can be utilized for design verification of FDM parts. This research contributes to further research into the development of RM metamaterials, specifically design analysis and verification tools for RM materials

Deep tillage tool optimization by means of finite element method: Case study for a subsoiler tine

Technologies and computer capacity currently available allow us to employ design software and numerical methods to solve complicated problems in very wide disciplines of engineering. It is also important for researches in agriculture. This study focused on obtaining optimum geometry parameters of a subsoiler tine by using computer aided engineering (CAE) applications. A field experiment was conducted to determine draft force of the subsoiler. The results from the experimental study were used in the finite element analysis (FEA) to simulate stress distributions on the subsoiler tine. The maximum equivalent stress of 432.49 MPa was obtained in the FEA. Visual investigations and FEA results showed that according to the tine’s material yield stress point of 355 MPa, plastic deformation was evident. Based on the FEA results, an optimization study was undertaken to obtain optimum geometry parameters without the occurrence of plastic deformation. According to the optimization study results, the optimum parameters of the tine geometry and maximum equivalent stress of 346.61 MPa were obtained. In addition to this, the total mass of the tine was reduced by about 0.367 kg

An exploration into the client at the heart of therapy : a qualitative perspective

Over 50 years ago Eysenck challenged the existing base of research into psychotherapy. Since that time, a large number of investigations have been conducted to verify the efficacy of therapy. Recently however, an increasing number of studies have cast new doubts on this research base. Instead of therapy being a function of the therapist, it is now becoming ever more apparent that the client plays a prime role in the therapeutic process. The qualitative studies presented in this paper provide some examples of research that demonstrates that clients are actively involved in their therapy, even making counselling work despite their counsellor. These studies suggest that clients may not experience therapy as beneficially as traditional outcome studies indicate. This raises a new challenge to researchers to more fully explore the client's experience of therapy, a challenge to which qualitative methods of inquiry would appear well suited

Automated clinical system for chromosome analysis

An automatic chromosome analysis system is provided wherein a suitably prepared slide with chromosome spreads thereon is placed on the stage of an automated microscope. The automated microscope stage is computer operated to move the slide to enable detection of chromosome spreads on the slide. The X and Y location of each chromosome spread that is detected is stored. The computer measures the chromosomes in a spread, classifies them by group or by type and also prepares a digital karyotype image. The computer system can also prepare a patient report summarizing the result of the analysis and listing suspected abnormalities

A Potential Research Area Under Shadow In Engineering:Agricultural Machinery Design and Manufacturing

As a branch of the global machinery industry, the agricultural (farm) machinery design and manufacturing or agricultural engineering industry has become one of the most important industries to be supported and focussed on in the era of hunger threats foreseen in the World’s future. In order to produce sufficient volumes of food from current limited agricultural land, well-designed machinery and high technology-supported mechanisation of the agricultural production processes is a vital necessity. However, although novel improvements are observed in this area, they are very limited. There is a lack of implementation of advanced engineering design and manufacturing technologies in this industry, therefore agricultural engineering could be considered a potential engineering research area with this in mind. This study aims to highlight the potential, gaps, sector specific challenges and limitations of the agricultural engineering research area at a macro level. Under consideration of the sector-specific indicators, the study revealed a major result: there is an insufficient level of sector-specific research on implementation strategies for up-to-date design and manufacturing technologies

Understanding the structure and dynamics of cationic surfactants from studies of pure solid phases

A homologous series of n-alkyl trimethylammonium bromide surfactants, H(CH2)nN+(CH3)3 Br, from C10TAB to C18TAB have been studied systematically in the bulk over a wide range of temperatures. Common features in the structures are identified, with packing dominated by the co-ordination of the cationic head groups with bromide anions and interdigitation of the hydrocarbon chains. This arrangement provides an explanation for the thin adsorbed bilayers that have been observed at various hydrophilic surfaces from aqueous solutions in previous studies. The molecular volumes and arrangement are comparable with structures of a number of different self-assembled amphiphiles. For these surfactants with bromide counter-ions, formation of crystal hydrates was not observed. The alkyl chains are highly mobile and at high temperatures a plastic phase is found for all materials with a transition enthalpy that is similar to the melting enthalpy of many long alkyl chains. Other unexpected phase transitions depend more markedly on the hydrocarbon chain length and evidently depend on delicate balances of the various contributions to the free energy

Design and structural optimisation of a tractor mounted telescopic boom crane

In this research, an application algorithm, which can be used in computer-aided design/engineering (CAD/CAE) and structural optimisation-based design studies of agricultural machineries, is introduced. This developed algorithm has been put in practice in a case study for a tractor mounted telescopic boom crane. The algorithm consists of both numerical and experimental methods and it includes material testing, three-dimensional (3D) computer-aided design and finite-element method (FEM)-based analysis procedures, structural optimisation strategy, physical prototyping, physical testing and design validation procedures. Following the visual and physical validation procedures carried out in the case study, the crane’s physical prototype was manufactured and the optimised design was approved for ongoing production. The study provides a unique CAD/CAE and experimentally driven total design pathway for similar products, which contributes to further research into the utilisation of engineering simulation technology for agricultural machinery design, analysis and related manufacturing subjects

Part II

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Liver enzyme elevations in a cohort of HIV/AIDS patients on first-line antiretroviral therapy in Namibia: Findings and implications

Introduction: All antiretroviral therapies (ARTs) are potentially toxic to the liver. In sub-Saharan Africa, the rising incidence of ART induced adverse events has complicated treatment leading to recent revisions of Namibian ART guidelines. Unfortunately there have been limited studies to date evaluating ART induced liver injury in Namibia to guide further revisions if needed. Objective: Determine the current patterns and grades of ALT elevation in Namibia’s HIV/AIDS. Methods: Retrospective cohort analysis. Patterns of alanine amino transferase (ALT) liver enzyme elevation were determined in a cohort of ART naïve HIV patients on firstline ART regimen in a referral hospital in Namibia over a 1 year treatment period. Patterns of ALT changes at baseline, 3 months and 6 months were analyzed using ANOVA and Bonferroni test for pairwise comparisons. Results: Of 79 eligible patients, 72 developed significant ALT elevation within 3 months of ART initiation (F (3, 76) = 6.4, p = 0.002, η2 = 0.193). Four 4 (5.6%) and 1 (1.38%) patient respectively developed grade 2 and grade 3 ALT elevation by month 3. There was no significant difference between mean ALT levels at baseline and month 6. A CD4 count of <350 cells/mm3; female gender and age over 40 years were the main factors associated with moderate or severe ALT elevation. Conclusions: First line ART commonly induces mild self-limiting liver enzyme elevation in Namibian HIV patients especially in the first 3 months. Consequently, there is a need to monitor ALT levels for at least 3 months after initiation mainly in high risk patients to reduce side-effect concerns. This is already happening

Evaluation of waist-to-height ratio to predict 5 year cardiometabolic risk in sub-Saharan African adults

Simple, low-cost central obesity measures may help identify individuals with increased cardiometabolic disease risk, although it is unclear which measures perform best in African adults. We aimed to: 1) cross-sectionally compare the accuracy of existing waist-to-height ratio (WHtR) and waist circumference (WC) thresholds to identify individuals with hypertension, pre-diabetes, or dyslipidaemia; 2) identify optimal WC and WHtR thresholds to detect CVD risk in this African population; and 3) assess which measure best predicts 5-year CVD riskPeer reviewedFinal Accepted Versio