125 research outputs found

    Magnetic field dependent viscous fluid-flow between squeezing plates with homogeneous and heterogeneous reactions

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    The impacts of magnetic field dependent viscous fluid is explored between squeezing plates in the presence of homogeneous and heterogeneous reactions. The unsteady constitutive equations of heat and mass transfers, modified Navier-Stokes, magnetic field and homogeneous and heterogeneous reactions are coupled as an system of ODE. The appropriate solutions are established for the vertical and axial induced magnetic field equations for the transformed and momentum as well as for the MHD pressure and torque exerted on the upper plate, and are in details. In the case of a smooth plate, the self-similar equation with acceptable starting assumptions and auxiliary parameters is solved by utilising a homotopy analytics method, to generate an algorithm with fast and guaranteed convergence. By comparing homotopy analytics method solutions with BVP4c numerical solver packaging, the validity and correctness of the homotopy analytics method findings are demonstrated. Magnetic Reynolds number have been shown to cause to decrease the distribution of magnetic field, fluid temperature, axial and tangential velocity. The magnetic field also has vertical and axial components with increasing viscosity. The applications of the investigation include car magneto-rheological shock absorbers, modern aircraft landing gear systems, procedures for heating or cooling, biological sensor systems, and bio-prothesis, etc

    Effectiveness of transcutaneous bilirubin measurement in managing neonatal jaundice in postnatal ward of a tertiary care hospital in Pakistan

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    Introduction: Neonatal jaundice is a common cause of concern in immediate newborn period for parents as well as for the caregivers. Babies with visible jaundice are identified by the healthcare provider, and blood samples are sent for confirmation. Clinical expertise varies from person to person and may lead to sending excessive blood sampling. Obtaining blood bilirubin samples is a painful procedure; it predisposes the baby to infections and requires skilled health personnel. Moreover, laboratory tests are costly and time consuming, leading to unnecessary delays in commencing phototherapy and discharge from hospital. Transcutaneous bilirubinometer has been in use for a long time as screening tool in postnatal wards. With passage of time, its accuracy and validity have improved tremendously.Methodology: We aim to implement a quality improvement initiative to reduce the number of blood bilirubin samples using transcutaneous bilirubin (TcBR) nomogram in full-term, low-risk babies who are born at our hospital and are admitted in postnatal ward after birth. Using preanalysis and postanalysis study design, this study will be performed in two phases of 6 months each. Data regarding total number of admissions in postnatal wards, demographics, serum bilirubin(TSBR) samplings and need for phototherapy will be recorded in both phases. TcBR will be done and recorded in postimplementation phase.Analysis And Results: Comparisons between the two groups will be made. Primary outcome will be reduction in blood bilirubin samples for TSBR after the implementation of TcBr protocol. The proportion of infants having TSBR performed in both periods will be compared. Crude sampling cost of TSBR will be obtained from laboratory, and cost comparison between two phases will be done to look for difference

    Wire coating analysis with Oldroyd 8-constant fluid by Optimal Homotopy Asymptotic Method

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    AbstractIn this study the wire coating in a pressure type die with the bath of Oldroyd 8-constant fluid with pressure gradient is investigated. The non-linear ordinary differential equation in dimensionless form is obtained, which is solved for the velocity profile using the Optimal Homotopy Asymptotic Method (OHAM). The effect of Dilatant constant α, the Psendoplastic constant β, and the pressure gradient on velocity distribution and shear stress is studied. Shear stress is examined under the effect of the viscosity parameter η0. Moreover, the volume flow rate and average velocity is carefully studied with changing the domain (thickness) of the polymer and varying the parameter α,β and the pressure gradient

    Self-Configurable Current-Mirror Technique for Parallel RGB Light-Emitting Diodes (LEDs) Strings

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    Traditional current-mirror circuits require buck converter to deal with one fixed current load. This paper deals with improved self-adjustable current-mirror methods that can address different LED loads under different conditions with the help of one buck converter. The operating principle revolves around a dynamic and self-configurable combinational circuit of transistor and op-amp based current balancing circuit, along with their op-amp based dimming circuits. The proposed circuit guarantees uniformity in the outputs of the circuit. This scheme of current-balancing circuits omitted the need for separate power supply to control the load currents through different kinds of LEDs, i.e. RGB LEDs. The proposed methods are identical and modular, which can be scaled to any number of parallel current sources. The principle methodology has been successfully tested in Simulink environment to verify the current balancing of parallel LED strings

    Numerical modelling of shallow foundation on multi-layer soil with varying stiffness

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    The load-deformation observation under the footing is essential for foundation design. Either experimental methods or numerical modelling generally determines this phenomenon in engineering practices. This study determined the settlement of shallow foundations on Multi-layer soil profile numerically. The settlement behavior was investigated through numerical modelling with Plaxis 2D. This study site was Jamshoro region, located in province Sindh, Pakistan. From the geotechnical investigation, the soil of Jamshoro region consists of a combination of different soils, mainly shale and limestone. This type of soil shows common challenges for the serviceable and sustainable design and construction of structural foundations. The standard penetration test conducted accompanied by other geotechnical tests on shale and limestone to determine the input parameters for the model and observe the soil profile. The Mohr-Coloumb model used for shale and linear elastic for limestone. The settlement of the foundation is attended by varying the limestone layer’s depth. In this research, the settlement reduced under the footing by increasing the thickness of the limestone layer. The study observed that stiffness of lower layer significantly reduces the settlement of shallow foundation. Therefore, the effect of lower layer should be considered for the designing of foundation on multi-layered soil

    Impact of diabetes mellitus on nerves

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    Background: Involvement of the peripheral and autonomic nervous systems is probably the most common complication of diabetes. The main symptoms of diabetic polyneuropathy include negative symptoms (those related to nerve fiber loss or dysfunction) such as numbness and weakness, and positive symptoms (those related to abnormal function of surviving nerve fibers) such as tingling and pain.Methods: This was a cross-sectional study held in diabetic clinic of Nishter hospital, Multan, Pakistan. The study included any diabetic patients showing symptoms of neuropathy.Results: There were total of 140 in this study. This study included 85% of male and 15% of female. Most common symptoms of diabetic neuropathy were pain (70%) and tingling (70%) followed by numbness in 65% of patients. There were 28 patients in 5 years duration of diabetes, 35 people in 6-10 years duration, 21 patients in 11-15 years duration, and 14 patients in 20+ years duration.Conclusions: Neuropathy due to diabetes is crippling especially when pain is the prominent symptoms. Autonomic symptoms like constipation and lightheadedness are discomforting for the patients. The most commonly used screening test is vibrating tuning fork test which is east to perform is clinical setting and is not time consuming. Diabetic patients need to take special care of

    Experimental investigation of engine valve train friction considering effects of operating conditions and WPC surface treatment

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    Reduction in friction ensures fuel economy, control on emissions and durability of components in internal combustion engines. A modern gasoline internal combustion engine was instrumented to determine the friction values at the cam–roller interface considering the effects of surface treatment and engine operating state. A series of tests under different operating speeds and lubricant inlet temperatures were undertaken using both an original surface roller and a Wonder Process Craft (WPC) surface-treated engine roller. The results clearly revealed a substantial reduction in friction magnitude for the WPC surface-treated engine roller in comparison to the original roller while operating under similar conditions, indicating their strong potential for employment in engines. An increase in friction with the rise in temperature was also observed for both types of rollers, whereas increased lubricant entraining velocity due to higher operating speed had the opposite impact. A considerable reduction in frictional drive torque ranging from 8% to 28% was observed by employing the WPC-treated roller in comparison to original/untreated roller at various operating conditions, which signifies the strong potential for employment of WPC surface treatment in the roller/follower valve train engines

    An efficient color LED driver based on self-configuration current mirror circuit

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    The string channel of Color LED driver with precise current balancing is proposed. It is noted that to drive a multiple LEDs string is by using a proper current source, due to the level of the brightness LED depends on the quantity of the current flows. In the production of LEDs, the variation in the forward voltage for each LED has been found significantly high. This variation causes different levels of brightness in LEDs. Then, controlling load current of LED by using a resistor to limit the LED current flowing is considered by associated with the forward voltage, instantly. Current sources have been designed to become immune to the above problem since it regulates the current, and not the voltage which flows through the LEDs. Hence, constant current source is the essential requirement to drive the LEDs. Besides, it is complex for color LEDs, dependent on the number of control nodes and dimming configuration. To arrange an accurate load current for the different sets of string color LEDs, the efficient LED driver is required, in which the current sharing is complement to each LED strings. Therefore, this paper suggests a color LED driver with self-configuration of enhanced current mirrors in multiple LED strings. The load currents have been efficiently balanced among the identical loads and unequal loads. The comparable efficiency of the string color LEDs losses has been shown thoroughly

    Sustainable economic growth potential of biomass-enriched countries through bioenergy production: State-of-the-art assessment using product space model

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    The current study aims to examine the economically viable biomass feedstocks for bioenergy generation and their export potential. The Product Space Model (PSM) is the primary tool used to achieve the aim by accomplishing certain objectives. The study’s findings show that Pakistan has abundant biomass resources for energy production. Canola oil, leather flesh wastes, and poultry fattening show the highest PRODY values, 46,735, 44,438, and 41,791, respectively. These have high-income potential and are considered feasible for export after meeting local energy demand. While goat manure, cashew nutshell, and cotton stalk show lower income potential having values of 3,641, 4,225, and 4,421, respectively. The biowastes having low-income potential are more beneficial to utilize in energy generation plants within the country. The United States is observed to make the most sophisticated products, indicated by an EXPY value of 36296.89. While the minimum level of sophistication is observed for Indonesia, as revealed by its EXPY value of 22235.41 among all considered countries. The PSM policy map analysis of the current study shows that Pakistan and Argentina are located in the Parsimonious Policy quadrant, suggesting shifting toward unexploited products closely related to the existing export baskets. Although the United States, China, India, Indonesia, and Brazil are found in the most desired Let-it-be Policy quadrant. They have more room to diversify their industries and enhance their export potential. The study has practical applications in economic, social, and environmental perspectives, focusing on economic, clean, and sufficient energy. Furthermore, exportable biomass feedstocks are identified to strengthen the economy. Further research must be conducted to evaluate other indicators of the PSM to explore the proximity aspect of PSM, as it would provide a clearer picture of bioenergy and biomass export prospects

    Outcomes following small bowel obstruction due to malignancy in the national audit of small bowel obstruction

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    Introduction Patients with cancer who develop small bowel obstruction are at high risk of malnutrition and morbidity following compromise of gastrointestinal tract continuity. This study aimed to characterise current management and outcomes following malignant small bowel obstruction. Methods A prospective, multicentre cohort study of patients with small bowel obstruction who presented to UK hospitals between 16th January and 13th March 2017. Patients who presented with small bowel obstruction due to primary tumours of the intestine (excluding left-sided colonic tumours) or disseminated intra-abdominal malignancy were included. Outcomes included 30-day mortality and in-hospital complications. Cox-proportional hazards models were used to generate adjusted effects estimates, which are presented as hazard ratios (HR) alongside the corresponding 95% confidence interval (95% CI). The threshold for statistical significance was set at the level of P ≤ 0.05 a-priori. Results 205 patients with malignant small bowel obstruction presented to emergency surgery services during the study period. Of these patients, 50 had obstruction due to right sided colon cancer, 143 due to disseminated intraabdominal malignancy, 10 had primary tumours of the small bowel and 2 patients had gastrointestinal stromal tumours. In total 100 out of 205 patients underwent a surgical intervention for obstruction. 30-day in-hospital mortality rate was 11.3% for those with primary tumours and 19.6% for those with disseminated malignancy. Severe risk of malnutrition was an independent predictor for poor mortality in this cohort (adjusted HR 16.18, 95% CI 1.86 to 140.84, p = 0.012). Patients with right-sided colon cancer had high rates of morbidity. Conclusions Mortality rates were high in patients with disseminated malignancy and in those with right sided colon cancer. Further research should identify optimal management strategy to reduce morbidity for these patient groups
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