2,371 research outputs found
Multistep Measurement of Plantar Pressure Alterations Using Metatarsal Pads
Metatarsal pads are frequently prescribed for nonoperative management of metatarsalgia due to various etiologies. When appropriately placed, they are effective in reducing pressures under the metatarsal heads on the plantar surface of the foot. Despite the positive clinical reports that have been cited, there are no quantitative studies documenting the load redistribution effects of these pads during multiple step usage within the shoe environment. The objective of this study was to assess changes in plantar pressure metrics resulting from pad use. Ten normal adult male subjects were tested during a series of 400-step trials. Pressures were recorded from eight discrete plantar locations at the hindfoot, midfoot, and forefoot regions of the insole. Significant increases in peak pressures, contact durations, and pressure-time integrals were noted at the metatarsal shaft region with pad use (P ≤ .05). Statistically significant changes in metric values were not seen at the other plantar locations, although metatarsal pad use resulted in mild decreases in mean peak pressures at the first and second metatarsal heads and slight increases laterally. Contact durations decreased at all metatarsal head locations, while pressure-time integrals decreased at the first, second, third, and fourth metatarsal heads. A slight increase in pressure-time integrals was seen at the fifth metatarsal head. The redistribution of plantar pressures tended to relate not only to the dimensions of the metatarsal pads, but also to foot size, anatomic foot configuration, and pad location. Knowledge of these parameters, along with careful control of pad dimensions and placement, allows use of the metatarsal pad as an effective orthotic device for redistributing forefoot plantar pressures
Proper Orthogonal Decomposition as a technique for identifying multiphase flow regime based on Electrical Impedance Tomography
Collecting very large amount of data from experimental measurement is a common practice in almost every scientific domain. There is a great need to have specific techniques capable of extracting synthetic information, which is essential to understand and model the specific phenomena. The Proper Orthogonal Decomposition (POD) is one of the most powerful data-analysis methods for multivariate and nonlinear phenomena. Generally, POD is a procedure that takes a given collection of input experimental or numerical data and creates an orthogonal basis constituted by functions estimated as the solutions of an integral eigenvalue problem known as a Fredholm equation. By utilising POD to identify flow structure in horizontal pipeline, specially, for slag, plug and wavy stratified air-water flow regimes, this paper proposes a novel approach, in which POD technique extends the current evaluation procedure of Electrical Impedance Tomography applied on air-water flow measurement. This extension is provided by implementation of the POD as an identifier of typical horizontal multiphase flow regimes. The POD snapshot matrices are reconstructed for EIT measurement domain and specific flow conditions. Direct POD method introduced by Lumley is applied. It is expected that this study may provide new knowledge on two phase flow dynamics in a horizontal pipeline and supportive information for further prediction of multiphase flow regime
Numerical modelling of gas-liquid flow phenomena in horizontal pipelines
Gas-liquid flows are omnipresent in industrial and environmental processes. Examples are the transportation of petroleum products [1, 2], the cooling of nuclear reactors [3, 4], the operation of absorbers [5], distillation columns [6], gas lift pumps [7] and many mores. Different input parameters induce topologically different flow patterns with different flow character and behaviour [7, 8] . The present study concentrate to diabatic incompressible two-phase flow in horizontal pipeline with separated character [9, 10] (Ugas < 10m/s and Uliquid < 0:2m/s) such as stratified wavy flow regime including typical multiphase instability (Kelvin-elmholtz instability) [11, 12]. The Proper Orthogonal Decomposition (POD) [13], introduced by Lumpay (1967) [14] was used to extract synthetic information essential to understand and to model flow dynamics phenomena. POD in this study are used to identify flow structure in the horizontal pipeline specially under transient of separated flow regimes. The snapshot matrix are reconstruct for specific flow sections and regimes. Present decomposition method, in this case used to analyse CFD data, are originally testing and developing for future using to analyse experimental data obtained by process tomography system [15]
Milk handling practices and utilization at dairy farms and collection centers under rural and peri-urban milk value chain systems in Nakuru County, Kenya
There are increasing expectations on the compliance of food products to safety and quality standards due to consumer demand for high-quality food. The aim of this study was to determine the quality tests that are carried out on raw milk and its utilization at three milk collection centers in Olenguruone and Dundori regions of Nakuru as well as some selected dairy farms. Using a semi-structured questionnaire, data were collected from milk collection centers’ staff and farmers. Milk sampling for quality control testing was done at both the cooperative delivery points and farm level. The quality of milk handled and stored in different containers was assessed. Descriptive statistics, Chi-square and logistic regression analysis were carried out on the data. Results indicated that the average quantity of milk received at all milk collection centers was about 3687 liters per day. It was noted that most of the milk collection centers’ staff (operators) had certificates or diplomas in dairy science. Their average job experience period in the milk sector was 7 years. Majority of the farmers (90%) and transporters (94%) used plastic containers for milk handling and storage. Farmers who used plastic containers for milking were approximately three times more likely to have their milk rejected compared to those who used mazzi cans, aluminium or stainless-steel containers (p<0.05; Odds ratio =3.20). The alcohol and lactometer tests were carried out on milk received at all collection centers studied. Resazurin test was only carried out in one collection center at Olenguruone that had the required laboratory equipment. Milk quality assessment was not done at the farm level. Traditional fermented milk was the common dairy product produced from evening milk in most dairy farmers’ households. Regular education programs and seminars on milk safety and quality should be provided to both collection centers’ operators and farmers. 
Sensory filtering disruption caused by poly I:C - Timing of exposure and other experimental considerations.
Maternal immune activation (MIA) in response to infection during pregnancy has been linked through various epidemiological and preclinical studies to an increased risk of neurodevelopmental disorders such as autism spectrum disorder (ASD) and schizophrenia in exposed offspring. Sensory filtering disruptions occur in both of these disorders and are typically measured using the acoustic startle response in both humans and rodents. Our study focuses on characterizing the baseline reactivity, habituation and prepulse inhibition (PPI) of the acoustic startle response following exposure to MIA. We induced MIA using polyinosinic: polycytidylic acid (poly I:C) at gestational day (GD) 9.5 or 14.5, and we tested sensory filtering phenotypes in adolescent and adult offspring. Our results show that startle reactivity was robustly increased in adult GD9.5 but not GD14.5 poly I:C offspring. In contrast to some previous studies, we found no consistent changes in short-term habituation, long-term habituation or prepulse inhibition of startle. Our study highlights the importance of MIA exposure timing and discusses sensory filtering phenotypes as they relate to ASD, schizophrenia and the poly I:C MIA model. Moreover, we analyze and discuss the potential impact of between- and within-litter variability on behavioural findings in poly I:C studies
Numerical simulation of multi-tubes tank heat exchanger: toward an optimized configuration
Heat recovery is the reutilization of thermal energy lost by any industrial and resident
ial application. Heat exchangers play a very effective role in recovering process. This paper deals with an optimization analysis of a suggested heat recovery heat exchanger. The suggested heat recovery heat exchanger is a multi-concentric tubes tank. This heat exchanger is designed to utilize thermal energy carried out by exhaust gases of a chimney to heat water for residential usage. The analysis is carried out numerically using a computational fluid dynamics “Comsol”software. Three configurations are considered, in which one tube, three tubes and six tubes systems are studied. The results show that in order to increase water temperature from 20°C to 70°C it requires 14 hours, 8 hours and 4 hours when using one tube, three tubes and six tubes system respectively. This makes six-tubed heat exchanger the best choice to heat the water quickly. However, one-tubed heat exchanger experiences the lowest corrosion phenomenon compared to other systems that makes one-tubed system to provide the longest lifetime
Day care laparoscopic surgery in gynaecology at a dedicated unit in Nairobi, Kenya
Objective: To evaluate and audit the outcomes of Gynaecological Day care Laparoscopic Surgery inNairobi,KenyaDesign: Retrospective case analysisSetting: The International Centre for Minimal Access Surgery, NairobiSubjects: one thousand three hundred and seventy nine patients undergoing Laparoscopic SurgeryResults: Between January 2011 to December 2015 a total of 1,379 Laparoscopic procedures were undertaken during the reporting period of which 1,121 ( 88.5 % ) were done as day procedures. In total 137 patients ( 9.9 % ) spent one night at ICMAS, 21 ( 1.5 % ) were transferred to a Major Hospital and 41 patients (2.9 %) underwent conversion to Laparotomy. There were two Hospital re-admissions (0.14 % ) and one complication ( 0.07% ), a bladder injury was encountered.Conclusions: Daycare surgery is a continually evolving speciality being competently performed by several units by various disciplines world over , including Kenya. In recent years the complexity of the procedures has increased with a wider range of patients being considered for challenging surgeries including those presenting with acute conditions. Our experiences have been favourable
Triple domestic heat recovery system: thermal modeling and parametric study
International audienc
Domestic thermoelectric cogeneration drying system: Thermal modeling and case study
The demand for reducing fuel consumption and mitigating exhaust fumes accountable for the greenhouse effect push toward developing efficient energy recovery systems. Optimizing the heat recovery process can be achieved by adding multi-recovery stages. In this frame, the present work suggests a new multi-stage recovery system for heating water and air and generating electricity. The concept of the system is applied to the exhaust gases of a chimney. A complete thermal modeling of the system is drawn. Then a case study is carried out for three different fed fuels (diesel, coal, wood). The results show that when diesel is used water temperature achieved 351 K and 240 W electric power is generated. Moreover, a 0.16 m2 heat recovery heat exchanger area is required to heat air to 363 K at an air flow rate of 0.0076 kg/s. Such system can recover up to 84% of the energy lost to the environment when wood is utilized as a fed fuel
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