The steady performance of a porous and compliant aerostatic thrust bearing

Recent developments in aerostatic thrust bearings have included: (a) the porous aerostatic thrust bearing containing a porous pad and (b) the inherently compensated compliant surface aerostatic thrust bearing containing a thin elastomer layer. Both these developments have been reported to improve the bearing load capacity compared to conventional aerostatic thrust bearings with rigid surfaces. This development is carried one stage further in a porous and compliant aerostatic thrust bearing incorporating both a porous pad and an opposing compliant surface. The thin elastomer layer forming the compliant surface is bonded to a rigid backing and is of a soft rubber like material. Such a bearing is studied experimentally and theoretically under steady state operating conditions. A mathematical model is presented to predict the bearing performance. In this model is a simplified solution to the elasticity equations for deflections of the compliant surface. Account is also taken of deflections in the porous pad due to the pressure difference across its thickness. The lubrication equations for flow in the porous pad and bearing clearance are solved by numerical finite difference methods. An iteration procedure is used to couple deflections of the compliant surface and porous pad with solutions to the lubrication equations. Comparisons between experimental results and theoretically predicted bearing performance are in good agreement. However these results show that the porous and compliant aerostatic thrust bearing performance is lower than that of a porous aerostatic thrust bearing with a rigid surface in place of the compliant surface. This discovery is accounted to the recess formed in the bearing clearance by deflections of the compliant surface and its effect on flow through the porous pad.

The controlled release of macromolecules from macroporous hydrophyllic polymer matrices

This work has used novel polymer design and fabrication technology to generate bead form polymer based systems, with variable, yet controlled release properties, specifically for the delivery of macromolecules, essentially peptides of therapeutic interest. The work involved investigation of the potential interaction between matrix ultrastructural morphology, in vitro release kinetics, bioactivity and immunoreactivity of selected macromolecules with limited hydrolytic stability, delivered from controlled release vehicles. The underlying principle involved photo-polymerisation of the monomer, hydroxyethyl methacrylate, around frozen ice crystals, leading to the production of a macroporous hydrophilic matrix. Bead form matrices were fabricated in controllable size ranges in the region of 100µm - 3mm in diameter. The initial stages of the project involved the study of how variables, delivery speed of the monomer and stirring speed of the non solvent, affectedthe formation of macroporous bead form matrices. From this an optimal bench system for bead production was developed. Careful selection of monomer, solvents, crosslinking agent and polymerisation conditions led to a variable but controllable distribution of pore sizes (0.5 - 4µm). Release of surrogate macromolecules, bovine serum albumin and FITC-linked dextrans, enabled factors relating to the size and solubility of the macromolecule on the rate of release to be studied. Incorporation of bioactive macromolecules allowed retained bioactivity to be determined (glucose oxidase and interleukin-2), whilst the release of insulin enabled determination of both bioactivity (using rat epididymal fat pad) and immunoreactivity (RIA). The work carried out has led to the generation of macroporous bead form matrices, fabricated from a tissue biocompatible hydrogel, capable of the sustained, controlled release of biologically active peptides, with potential use in the pharmaceutical and agrochemical industries.

The effects of solid contamination in hydraulic fluids on axial piston pumps

The fluids used in hydraulic systems inevitably contain large numbers of small, solid particles, a phenomenon known as 'fluid contamination'. Particles enter a hydraulic system from the environment, and are generated within it by processes of wear. At the same time, particles are removed from the system fluid by sedimentation and in hydraulic filters. This thesis considers the problems caused by fluid contamination, as they affect a manufacturer of axial piston pumps. The specific project aim was to investigate methods of predicting or determining the effects of fluid contamination on this type of pump. The thesis starts with a theoretical analysis of the contaminated lubrication of a slipper-pad bearing. Statistical methods are used to develop a model of the blocking, by particles, of the control capillaries used in such bearings. The results obtained are compared to published, experimental data. Poor correlation between theory and practice suggests that more research is required in this area before such theoretical analysis can be used in industry. Accelerated wear tests have been developed in the U.S.A. in an attempt to predict pump life when operating on contaminated fluids. An analysis of such tests shows that reliability data can only be obtained from extensive test programmes. The value of contamination testing is suggested to be in determining failure modes, and in identifying those pump components which are susceptible to the effects of contamination. A suitable test is described, and the results of a series of tests on axial piston pumps are presented and discussed. The thesis concludes that pump reliability data can only be obtained from field experience. The level of confidence which can be placed in results from normal laboratory testing is shown to be too low for the data to be of real value. Recommendations are therefore given for the ways in which service data should be collected and analysed.

Semantics of query-driven communication of exact values

We address the question of how to communicate among distributed processes valuessuch as real numbers, continuous functions and geometrical solids with arbitrary precision, yet efficiently. We extend the established concept of lazy communication using streams of approximants by introducing explicit queries. We formalise this approach using protocols of a query-answer nature. Such protocols enable processes to provide valid approximations with certain accuracy and focusing on certain locality as demanded by the receiving processes through queries. A lattice-theoretic denotational semantics of channel and process behaviour is developed. Thequery space is modelled as a continuous lattice in which the top element denotes the query demanding all the information, whereas other elements denote queries demanding partial and/or local information. Answers are interpreted as elements of lattices constructed over suitable domains of approximations to the exact objects. An unanswered query is treated as an error anddenoted using the top element. The major novel characteristic of our semantic model is that it reflects the dependency of answerson queries. This enables the definition and analysis of an appropriate concept of convergence rate, by assigning an effort indicator to each query and a measure of information content to eachanswer. Thus we capture not only what function a process computes, but also how a process transforms the convergence rates from its inputs to its outputs. In future work these indicatorscan be used to capture further computational complexity measures. A robust prototype implementation of our model is available.

Maternal periconceptional and gestational low protein diet affects mouse offspring growth, cardiovascular and adipose phenotype at 1 year of age

Human and animal studies have revealed a strong association between periconceptional environmental factors, such as poor maternal diet, and an increased propensity for cardiovascular and metabolic disease in adult offspring. Previously, we reported cardiovascular and physiological effects of maternal low protein diet (LPD) fed during discrete periods of periconceptional development on 6-month-old mouse offspring. Here, we extend the analysis in 1 year aging offspring, evaluating mechanisms regulating growth and adiposity. Isocaloric LPD (9% casein) or normal protein diet (18% casein; NPD) was fed to female MF-1 mice either exclusively during oocyte maturation (for 3.5 days prior to mating; Egg-LPD, Egg-NPD, respectively), throughout gestation (LPD, NPD) or exclusively during preimplantation development (for 3.5 days post mating; Emb-LPD). LPD and Emb-LPD female offspring were significantly lighter and heavier than NPD females respectively for up to 52 weeks. Egg-LPD, LPD and Emb-LPD offspring displayed significantly elevated systolic blood pressure at 52 weeks compared to respective controls (Egg-NPD, NPD). LPD females had significantly reduced inguinal and retroperitoneal fat pad: body weight ratios compared to NPD females. Expression of the insulin receptor (Insr) and insulin-like growth factor I receptor (Igf1r) in retroperitoneal fat was significantly elevated in Emb-LPD females (P&0.05), whilst Emb-LPD males displayed significantly decreased expression of the mitochondrial uncoupling protein 1 (Ucp1) gene compared to NPD offspring. LPD females displayed significantly increased expression of Ucp1 in interscapular brown adipose tissue when compared to NPD offspring. Our results demonstrate that aging offspring body weight, cardiovascular and adiposity homeostasis can be programmed by maternal periconceptional nutrition. These adverse outcomes further exemplify the criticality of dietary behaviour around the time of conception on long-term offspring health. © 2011 Watkins et al.

Modulation of interleukin-6 and matrix metalloproteinase 2 expression in human fibroblast-like synoviocytes by functional ionotropic glutamate receptors

Objective. Patients with rheumatoid arthritis (RA) have increased concentrations of the amino acid glutamate in synovial fluid. This study was undertaken to determine whether glutamate receptors are expressed in the synovial joint, and to determine whether activation of glutamate receptors on human synoviocytes contributes to RA disease pathology. Methods. Glutamate receptor expression was examined in tissue samples from rat knee joints and in human fibroblast-like synoviocytes (FLS). FLS from 5 RA patients and 1 normal control were used to determine whether a range of glutamate receptor antagonists influenced expression of the proinflammatory cytokine interleukin-6 (IL-6), enzymes involved in matrix degradation and cytokine processing (matrix metalloproteinase 2 [MMP-2] and MMP-9), and the inhibitors of these enzymes (tissue inhibitor of metalloproteinases 1 [TIMP-1] and TIMP-2). IL-6 concentrations were determined by enzyme-linked immunosorbent assay, MMP activity was measured by gelatin zymography, and TIMP activity was determined by reverse zymography. Fluorescence imaging of intracellular calcium concentrations in live RA FLS stimulated with specific antagonists was used to reveal functional activation of glutamate receptors that modulated IL-6 or MMP-2. Results. Ionotropic and metabotropic glutamate receptor subunit mRNA were expressed in the patella, fat pad, and meniscus of the rat knee and in human articular cartilage. Inhibition of N-methyl-D-aspartate (NMDA) receptors in RA FLS increased proMMP-2 release, whereas non-NMDA ionotropic glutamate receptor antagonists reduced IL-6 production by these cells. Stimulation with glutamate, NMDA, or kainate (KA) increased intracellular calcium concentrations in RA FLS, demonstrating functional activation of specific ionotropic glutamate receptors. Conclusion. Our findings indicate that activation of NMDA and KA glutamate receptors on human synoviocytes may contribute to joint destruction by increasing IL-6 expression. © 2007, American College of Rheumatology.

Cooling of greenhouses using seawater:a solar driven liquid-desiccant cycle for greenhouse cooling in hot climates

Evaporative pads are frequently used for the cooling of greenhouses. However, a drawback of this method is the consumption of freshwater. In this paper it is shown, both theoretically and through a practical example, that effective evaporative cooling can be achieved using seawater in place of fresh water. The advantages and drawbacks of using seawater are discussed more generally. In climates that are both hot and humid, evaporative systems cannot always provide sufficient cooling, with the result that cultivation often has to be halted during the hottest months of the year. To overcome this, we propose a concept in which a desiccant pad is used to dehumidify the air before it enters the evaporative pad. The desiccant pad is supplied with a hygroscopic liquid that is regenerated by the energy of the sun. The performance of this concept has been modelled and the properties of various liquids have been compared. An attractive option is to obtain the liquid from seawater itself, given that seawater contains hygroscopic salts such as magnesium chloride. Preliminary experiments are reported in which magnesium chloride solution has been regenerated beneath a solar simulator.

The effects of store atmosphere on shopping behaviour - A literature review.

This paper provides an insight into how the atmospherics of a retail environment influence shopping behaviour. Its objective is to support researchers and practitioners by summarizing the current state of knowledge and identifying gaps and avenues for future research. The scope covers studies in retail marketing and environmental psychology published during the last 35 years. It has been shown that environmental cues (music, scent etc.) have an effect on the emotional state of the consumer, which in turn causes behavioural changes, both positive (approach, buy more, stay longer etc.) and negative (not approach, buy less, leave earlier etc.). Most studies make reference to the PAD model, which proposes that the relevant emotions in this process can be measured along three dimensions Pleasure, Arousal and Dominance (Mehrabian, A. & Russell, J.A.,1974, An approach to environmental psychology, Cambridge, MA.: MIT Press). Since then, significant advances have been made to understand the effect of individual cues, their interaction, as well as the role of moderators, such as gender, age, or shopping motivation. However, there are a number of opportunities for further research. Too little is known about the moderating effects of Arousal and Dominance and how they interact with each other and with Pleasure dimension. Also a number of other moderators, such as gender and culture, should be integrated into the model.

Development of a dynamic headspace concentration technique for the non-contact sampling of human odor samples and the creation of canine training aids

Human scent and human remains detection canines are used to locate living or deceased humans under many circumstances. Human scent canines locate individual humans on the basis of their unique scent profile, while human remains detection canines locate the general scent of decomposing human remains. Scent evidence is often collected by law enforcement agencies using a Scent Transfer Unit, a dynamic headspace concentration device. The goals of this research were to evaluate the STU-100 for the collection of human scent samples, and to apply this method to the collection of living and deceased human samples, and to the creation of canine training aids. The airflow rate and collection material used with the STU-100 were evaluated using a novel scent delivery method. Controlled Odor Mimic Permeation Systems were created containing representative standard compounds delivered at known rates, improving the reproducibility of optimization experiments. Flow rates and collection materials were compared. Higher air flow rates usually yielded significantly less total volatile compounds due to compound breakthrough through the collection material. Collection from polymer and cellulose-based materials demonstrated that the molecular backbone of the material is a factor in the trapping and releasing of compounds. The weave of the material also affects compound collection, as those materials with a tighter weave demonstrated enhanced collection efficiencies. Using the optimized method, volatiles were efficiently collected from living and deceased humans. Replicates of the living human samples showed good reproducibility; however, the odor profiles from individuals were not always distinguishable from one another. Analysis of the human remains samples revealed similarity in the type and ratio of compounds. Two types of prototype training aids were developed utilizing combinations of pure compounds as well as volatiles from actual human samples concentrated onto sorbents, which were subsequently used in field tests. The pseudo scent aids had moderate success in field tests, and the Odor pad aids had significant success. This research demonstrates that the STU-100 is a valuable tool for dog handlers and as a field instrument; however, modifications are warranted in order to improve its performance as a method for instrumental detection.

Profiling The Campus Recruiter At A Four-Year Hospitality Program

Profiling the Campus Recruiter At a Four-Year Hospitality Program, is a written profile, supported by anecdotal rather than stridently empirical evidence, by Al lzzolo, Assistant Professor, College of Hotel Administration, University of Nevada, Las Vegas. “Each year major chain corporations as well as single unit companies interview hospitality students throughout the country. A study conducted at the University of Nevada, Las Vegas, was designed to profile the hospitality industry campus recruiter and to provide meaningful data to college students who would be interviewing with these recruiters,” the author initially proffers. “Recruiting at the four-year hospitality program, by its nature, is not a science, nor is it highly quantifiable. The interviewing and selection processes are highly subjective and vary from company to company,” says Izzolo to preface his essay. “Data were collected via a questionnaire specifically designed to answer questions about the recruiters and/or the companies that sent interviewers to the placement office of the university's hospitality program,” our author says to explain the process used to gather information for the piece. Findings of the study indicate that the typical recruiter is male, college educated – but not necessarily in a Hospitality’ curriculum – and almost 80 percent of respondents said they had the authority to hire management trainees. Few campuses are visited by hospitality industry recruitment staff as evidenced by Izzolo’s observations/data. Table 3 analyzes the desirable traits a recruiter deems appropriate for the potential employee candidate. Personal appearance, work experience, grade point average, and verbal communication rank high on the list of distinguishable attributes. The most striking finding in this portion of the study is that a student’s GPA is virtually ignored. “Recruiting for the hospitality industry appears to be very subjective,” Izzolo says. “Recruiters are basing decisions to hire not on knowledge levels as determined by an academic grade point average but rather on criteria much less definitive, such as verbal skills and personal appearance,” our author opines. In closing, Izzolo concedes this is not a definitive study, but is merely a launching pad to a more comprehensive investigation on the recruitment subject.

Reliability analysis of encapsulation methods for lead -based paint through an accelerated life testing

The adverse health effects of long-term exposure to lead are well established, with major uptake into the human body occurring mainly through oral ingestion by young children. Lead-based paint was frequently used in homes built before 1978, particularly in inner-city areas. Minority populations experience the effects of lead poisoning disproportionately. ^ Lead-based paint abatement is costly. In the United States, residents of about 400,000 homes, occupied by 900,000 young children, lack the means to correct lead-based paint hazards. The magnitude of this problem demands research on affordable methods of hazard control. One method is encapsulation, defined as any covering or coating that acts as a permanent barrier between the lead-based paint surface and the environment. ^ Two encapsulants were tested for reliability and effective life span through an accelerated lifetime experiment that applied stresses exceeding those encountered under normal use conditions. The resulting time-to-failure data were used to extrapolate the failure time under conditions of normal use. Statistical analysis and models of the test data allow forecasting of long-term reliability relative to the 20-year encapsulation requirement. Typical housing material specimens simulating walls and doors coated with lead-based paint were overstressed before encapsulation. A second, un-aged set was also tested. Specimens were monitored after the stress test with a surface chemical testing pad to identify the presence of lead breaking through the encapsulant. ^ Graphical analysis proposed by Shapiro and Meeker and the general log-linear model developed by Cox were used to obtain results. Findings for the 80% reliability time to failure varied, with close to 21 years of life under normal use conditions for encapsulant A. The application of product A on the aged gypsum and aged wood substrates yielded slightly lower times. Encapsulant B had an 80% reliable life of 19.78 years. ^ This study reveals that encapsulation technologies can offer safe and effective control of lead-based paint hazards and may be less expensive than other options. The U.S. Department of Health and Human Services and the CDC are committed to eliminating childhood lead poisoning by 2010. This ambitious target is feasible, provided there is an efficient application of innovative technology, a goal to which this study aims to contribute. ^

Relação entre desempenho funcional e indicadores de doença arterial obstrutiva periférica em idosas

The presence of peripheral arterial disease (PAD) increases the risk and vulnerability to adverse clinical outcomes in the elderly. Like this, we investigated the relationship between functional performance and indicators of PAD in elderly women. METHODS: Cross-sectional study in which 54 elderly were assessed by questionnaire mini mental state examination, Short Phisical Performance Battery (SPPB), ankle-brachial index (ABI), human activity profile (HAP) and Edinburgh questionnaire. Statistical analysis was performed using ANOVA, t test and Pearson correlation. We considered p <0.05 as significance level. RESULTS: The mean age SPPB and ABI were 69.2 (± 6.9) years, SPPB 9.42 (± 2.55) and ABI 1.04 (± 0.14). The prevalence of PAD was 16.3%. There was a significant correlation between ABI and gait speed (r = 0.75, p = 0.001) and between PAH with SPPB (p = 0.001). CONCLUSIONS: It is suggested that the decline in functional performance in older, expressed in gait velocity component of the SPPB, is related to the presence of PAD

Efeito agudo da respiração abdominal lenta sobre a atividade cerebral, respostas emocionais e cardiovasculares

Introduction: Slow abdominal breathing (SAB) stimulates baroreflex and generates respiratory sinus arrhythmia, changing cardiovascular, emotional and cerebral systems acute and chronically. However, although meditative practices have been receiving increasingly attention in the last years, there is no agreement on the neurophysiological changes underlying them, mainly because of the lack of topographical pieces of information. Purpose: We aimed to analyze the acute effect of SAB on brain activity, emotional and cardiovascular responses in untrained subjects in meditative techniques. Methods: Seventeen healthy adults’ men were assessed into two different sessions in a random and crossed order. Into experimental session, they breathed in 6 cycles/minute and in control session they kept breathing in normal rate, both for 20 minutes. xi Before, during, and after each session we assessed brain activity using electroencephalography (EEG), anxiety, mood, heart rate variability (HRV) and blood pressure. The sLORETA software was used to analyze EEG data for source localization of brain areas in which activity was changed. Results: The sLORETA showed that beta band frequency was reduced in frontal gyrus (P<0.01) and anterior cingulate cortex (P<0.05) both during and after SAB (P<0.05) compared to the moment before it. There was no change in brain activity in control session. Additionally, a two-way repeated measures ANOVA showed that there was no effect on anxiety (P>0.8) and mood (P>0.08). There were improvements in HRV (P<0.03), with increased RR interval and decreased HR after SAB, as well as increased SDNN, RMSSD, pNN50, low frequency, LF/HF ratio, and total power during it, with no changes in SBP and DBP. Conclusions: We conclude that SAB is able to change brain activity in areas responsible for emotional processing, even without behavioral changes. Furthermore, SAB improves HRV and does not change blood pressure in normotensive.

Efeitos do treino resistido na capacidade funcional e na reatividade pressórica em pacientes intradialíticos

Pacientes com doença renal crônica (DRC) submetidos ao treinamento resistido durante a hemodiálise apresentam benefícios substanciais dos sistemas muscular e cardiovascular, da capacidade funcional e da sua qualidade de vida. Entretanto, as melhorias na reatividade pressórica ainda não estão bem esclarecidas. O objetivo foi analisar o efeito do treino resistido na melhora da capacidade funcional e da reatividade pressórica em pacientes hemodialisados, em Natal/RN no ano de 2014. Trata-se de um ensaio clínico controlado e randomizado, com amostra de 64 pacientes, com média de idade de 42,28 (±11,48) anos, distribuídos em grupo experimental (GE) e controle (GC). Para mensurar os ganhos de força de membros inferiores foram utilizados os testes de sentar e levantar e de levantar e caminhar, já para a reatividade pressórica o teste cold pressor, em ambos os grupos antes e após a intervenção. Além disso, apenas o GE participou do treinamento resistido durante a hemodiálise em 16 semanas, composto por 3 sessões semanais, 3 séries de 10 repetições máximas (RM) estimadas (para extensores de joelho e flexores de quadril e joelho), entre 50 a 70% de 10 RM. Para a intensidade do treinamento foi utilizada a escala de Borg entre 11 a 14 durante as seções. Os dados foram analisados utilizando o Teste t para amostras independentes (inter-grupos) bem como para comparar a diferença das médias nos grupos pré e pós-intervenção (intra-grupos) a partir do Teste t para amostras repetidas. Para todas as variáveis foi considerada a significância estatística de 5% executados no software SPSS® 20.0. O estudo foi aprovado pelo comitê de ética do Hospital Universitário Onofre Lopes (HUOL - UFRN) número 37992214.2.0000.5292. Após a intervenção, verificou-se que os pacientes do GE tiveram um desempenho melhor nos testes de força (p<0,001) em comparação ao GC. Resultado também observado na pressão arterial sistólica e diastólica (PAS e PAD) ambas de repouso que apresentaram redução dos níveis pressóricos apenas no GE (p<0,001). Na reatividade pressórica tanto nos períodos pré bem como após 2 minutos também demonstraram reduções estatisticamente significativas do GE (p<0,001 e p=0,012) respectivamente quando comparado ao GC. Conclui-se que o treinamento resistido melhorou desempenho nos testes de força de membros inferiores beneficiando a capacidade funcional dos pacientes em hemodiálise, como também a pressão arterial de repouso e os níveis de reatividade pressórica obtiveram reduções significativas de seus valores após a intervenção. Além disso, este tipo de treinamento também pode ser utilizado como uma estratégia de proteção aos fatores de risco cardiovascular em pacientes renais crônicos.

Gestão e mapeamento de processos nas instituições públicas: um estudo de caso na Diretoria de Administração de Pessoal da Universidade Federal do Rio Grande do Norte

The new management models have led to the reorganization of institutions today. Much is made in improving the delivery of public services entities, and they have sought to adopt these new initiatives in order to improve the quality of the product or service offered to users. The modernization of the management model at the Federal University of Rio Grande do Norte (UFRN) strengthened by the accession of the institution to GesPública Program, which focuses on the management modernization leading institutions to seek ways to fit to meet the demands proposed the Program. Therefore, the Department of Personnel Administration (DAP) has structured its processes and procedures using the mapping tool processes. This research starts from the question: what were the results obtained with the implementation of the management and process mapping of PAD? It is proposed as a general objective to analyze the management and the mapping of that Board processes, identifying the possible benefits in improving the quality of the services provided to users. The specific objectives to achieve results, are pointed out: describe how you carried out the implementation of the management and process mapping in DAP and how it is working at the moment; examine the line in the relationship between the actions developed by the DAP and modern theories of this theme; identify the evolution of the sector with the measures adopted and the results obtained with the implementation of the mapping tool. In the theoretical framework, it was approached a brief history of the evolution of public administration in Brazil, GesPública program and its importance for process management in public institutions as well as the Management and Process Mapping. The context of the study was the DAP, and participants were managers of the institution in the survey. Data collection was done through the study of the institution's documents, bibliography analysis available on the topic, questionnaires and semi-structured interviews with professionals of the institution involved with the object of study, since its inception until July 2015, when it was finished the search. As a result, were listed: the motivation, importance, benefits and innovations that management and the mapping of processes brought to the institution, point out what has been improved in the service users and the tools used. We also analyze the main problems identified during the implementation of the mapping. As a suggestion, it was analyzed how these procedures can, if possible, be extended to other sectors of UFRN.