Numerical simulation of moving rigid body in rarefied gases

In this paper we present a numerical scheme to simulate a moving rigid body with arbitrary shape suspended in a rarefied gas. The rarefied gas is simulated by solving the Boltzmann equation using a DSMC particle method. The motion of the rigid body is governed by the Newton-Euler equations, where the force and the torque on the rigid body is computed from the momentum transfer of the gas molecules colliding with the body. On the other hand, the motion of the rigid body influences the gas flow in its surroundings. We validate the numerical results by testing the Einstein relation for Brownian motion of the suspended particle. The translational as well as the rotational degrees of freedom are taken into account. It is shown that the numerically computed translational and rotational diffusion coefficients converge to the theoretical values.Comment: 16 pages, 8 figure

Sensitivity of Hazus-MH Flood Loss Estimates to Selection of Building Parameters: Two Illinois Case Studies

In this study, Hazus-MH (v 2.1 SP 2) flood-loss estimation tools were assessed for their sensitivity to an array of different building and model parameters. The purpose of this study is to help guide users of the Hazus-MH flood-loss modeling tool in the selection of most appropriate model parameters. Six model parameters (square footage of the building, building age, construction types, foundation types, first floor heights, and the number of stories in the building) were assessed for their impacts on flood losses using the Hazus-MH user defined and aggregate flood-loss models. Building stock databases for these analyses were developed using county assessor records from two Illinois counties. A validation assessment was also performed using observed flood-damage survey data collected after the 2011 Mississippi River Flood which inundated the Olive Branch Area in Alexander County, Illinois. This analysis was performed to assess the accuracy of the detailed Hazus-MH User Defined Facility (UDF) flood-loss modeling tool. The foundation types and its associated first floor heights and number of stories in the building were found to substantially impact flood-loss estimates using the Hazus-MH flood-loss modeling tool. The model building parameters square footage, building age and construction type had little or no effect on the flood-loss estimates. The validation assessment reveled Hazus-MH UDF flood-loss modeling tool is capable of providing a reasonable estimate of actual flood losses. The validation assessment showed the modeled results to be within 23% of actual losses. The validation study results attained in this study using the detailed UDF flood-loss modeling tool where more realistic (within 23% of actual losses versus \u3e 50% of actual losses) than previous Hazus-MH flood-loss validation assessments. The flood-loss estimates could be further improved by modifying or choosing a more region specific depth-damage curve, using higher resolution DEM and improving the flood-depth grid by incorporating more detailed flood elevation data or estimates using detailed hydraulic models that better reflects the local inundation conditions

Perioperative outcomes after open radical cystectomy for muscle invasive bladder cancer

Introductions: Radical cystectomy with bilateral pelvic lymphadenectomy is a primary intervention for muscle invasive or refractory, high grade Ta, T1, Tis bladder cancer. Owing to its major undertaking, patient succumbs to infection and various morbidities. This study was to assess the perioperative outcomes and complications of radical cystectomy. Methods: This retrospective study analyzed the perioperative outcome (early mortality within 30 days, length of stay, requirement of blood transfusion) of radical cystectomy in patients with bladder cancer during four years at Patan Hospital, Patan Academy of Health Sciences, Lalitpur, Nepal. Ethical approval was obtained. Study variables included patient’s demographics, presenting symptoms, tumor types and configuration, need for blood transfusion, length of surgery, pathological stages, types of urinary diversions, hospital stay, early (<30 days) and late (31-90 days) morbidity and mortality. Results: Total 32 patients underwent radical cystectomy. Data analysed on 18 patients, mean age was 66.7 years and painless hematuria 17 (94.4%). All were transitional cell carcinoma, high grade lesion in 17 (94.4%). Overall 6 (33.3%) patients developed early postoperative complications, paralytic ileus and prolong lymph drainage in 5 (27.8%), wound dehiscence in 4 (22.2%) and ureteric catheter dislodgement in two. There were 2 (11.1% of 18) mortalities (the mortality audit showed total 5 (15.6%) out of 32 radical cystectomy during the study period Conclusions: Perioperative complications occurred in 1/3rd following radical cystectomy for muscle invasive bladder, more complications in those with preoperative associated co-morbidities. Keywords: bladder cancer, radical cystectomy, perioperative complication

Clinico-pathological characteristics of colorectal carcinoma at university teaching hospital, Nepal

Introductions: Colorectal cancer is a major health problem in developingcountries. The purpose of this study was to analyze the clinico-pathologicalcharacteristics of colorectal carcinoma at Patan hospital, Nepal.Methods: A retrospective chart review was done for patients operatedfor colorectal carcinoma at Patan Hospital from May 2004 to April 2012.Demographic information, chief complains, site of primary cancer, andhistological types were analyzed.Results: There were 73 patients (37 males and 36 females) with colorectalcarcinoma. The mean age was 52 years. There were 21 (28.77%) patients below 40 years of age. Patients with rectal carcinoma presented with bleeding per rectum in 69.70% and 60% of patients with colon cancer presented with pain abdomen. Rectum was involved in 31 (42.47%) and right colon in 30 (41.10%). Adenocarcinoma was seen in 72 (98.63%).Conclusions: The colorectal carcinoma is not only the disease of old age. Wehad 29% of our patients below 40 year. Rectum and right colon were equallyaffected.Keywords: bleeding, colorectal carcinoma, pain abdome

Thermophoresis of Janus particles at large Knudsen numbers

The force and torque on a Janus sphere moving in a rarefied gas with a thermal gradient are calculated. The regime of large Knudsen number is considered, with the momenta of impinging gas molecules either obtained from a Chapman-Enskog distribution or from a binary Maxwellian distribution between two opposing parallel plates at different temperature. The reflection properties at the surface of the Janus particle are characterized by accommodation coefficients having constant but dissimilar values on each hemisphere. It is shown that the Janus particle preferentially orients such that the hemisphere with a larger accommodation coefficient points towards the lower temperature. The thermophoretic velocity of the particle is computed, and the influence of the thermophoretic motion on the magnitude of the torque responsible for the particle orientation is studied. The analytical calculations are supported by Direct Simulation Monte Carlo results, extending the scope of the study towards smaller Knudsen numbers. The results shed light on the efficiency of oriented deposition of nanoparticles from the gas phase onto a cold surface

Conversion from Laparoscopic to Open Cholecystectomy

Introductions: With the advent of newer technology, the era of open surgery for gall bladder diseases has been preferably taken over by laparoscopic cholecystectomy. However, certain cases still require conversion to open surgery. In this review we aim to analyze the reason for conversion.Methods: This retrospective study was conducted at Patan Hospital, Patan Acdemy of Health Sciences, Nepal. All patients who underwent laparoscopic cholecystectomy from February 2009 to July 2012 were included in the study. File numbers of all the patients were obtained from operation room register. The patient files were analyzed for age, sex, duration of symptoms, liver function tests, ultrasound findings and the description in operation note for reason for conversion.Results: The age ranged from 12 to 81 years with mean age of patients 32.76 years and male to female ratio 1:2.9. The mean operating time was 65 minutes and average post operative hospital stay was 1.61 days. Out of 305 patients, 34 (11.14%) required open conversion. Factors esponsible for open conversion were dense fibrosis at Calots in 11 (3.6%), adhesions due to previous abdominal surgery in 6 (1.9%), uncontrollable bleeding in 5 (1.6%), bile duct injury in 4 (1.3%) cholecystoenteric fistula in 3 (0.9%), Mirizzi’s syndrome 2(0.6%).Conclusions: Adhesions at the calot’s triangle was the common reason for conversion from laparoscopic to open cholecystectomy.Keywords: adhesions, conversion, gallstone, laparoscopic cholecystectom

Solid-Substrate Fermentation of Corn Fiber by Phanerochaete chrysosporium and Subsequent Fermentation of Hydrolysate into Ethanol

The goal of this study was to develop a fungal process for ethanol production from corn fiber. Laboratory-scale solid-substrate fermentation was performed using the white-rot fungusPhanerochaete chrysosporium in 1 L polypropylene bottles as reactors via incubation at 37 °C for up to 3 days. Extracellular enzymes produced in situ by P. chrysosporium degraded lignin and enhanced saccharification of polysaccharides in corn fiber. The percentage biomass weight loss and Klason lignin reduction were 34 and 41%, respectively. Anaerobic incubation at 37 °C following 2 day incubation reduced the fungal sugar consumption and enhanced the in situ cellulolytic enzyme activities. Two days of aerobic solid-substrate fermentation of corn fiber with P. chrysosporium, followed by anaerobic static submerged-culture fermentation resulted in 1.7 g of ethanol/100 g of corn fiber in 6 days, whereas yeast (Saccharomyces cerevisiae) cocultured with P. chrysosporium demonstrated enhanced ethanol production of 3 g of ethanol/100 g of corn fiber. Specific enzyme activity assays suggested starch and hemi/cellulose contribution of fermentable sugar

Refractive Status in Nepalese Pre-Term and Full-Term Infants Early in Life.

SIGNIFICANCE: This study suggests that pre-term infants, even without retinopathy of prematurity, are at risk for abnormal refractive development and informs the need for close monitoring of refractive error in such infants, regardless of their retinopathy of prematurity status. PURPOSE: The present study aims to investigate the refractive error trend in Nepalese pre-term infants without retinopathy of prematurity (ROP) in the first 6 months of life and explore the association of refractive error with birth weight (BW) and gestational age (GA). METHODS: Thirty-six pre-term infants without ROP and 40 full-term infants underwent cycloplegic retinoscopy at birth, term (for pre-term only), 3 months, and 6 months chronologically. Refractive status was classified into emmetropia (mean spherical equivalent refraction [SER] 0 to +3.00D), myopia (SER +3.00D). Refractive parameters at various age points were compared between the pre-term and full-term infants using general linear model repeated measures ANOVA. RESULTS: At birth, the SER in the pre-term infants was +0.84 ± 1.72D; however, there was a shift toward myopia at 6 months of age (SER = -0.33 ± 1.95D). There was a significant difference in SER, astigmatism, and anisometropia between pre-term and full-term infants by 6 months of age (P < .01). Astigmatism and anisometropia showed an increasing trend with age in pre-term infants (P < .05 at 6 months) in contrast to a decreasing trend in full-term infants (P < 0.05 at 3 and 6 months). In pre-term infants, there was a statistically significant positive relationship between GA and SER (β = 0.32, R = 17.6%, P < .05) but a negative relationship between BW and astigmatism (β = -1.25, R = 20.6%, P < .01). CONCLUSIONS: Pre-term infants who do not develop ROP show a trend toward increasing myopia and demonstrate greater astigmatism and anisometropia than full-term infants in their first 6 months of life

Foodborne Outbreak Investigation in a Festival at Panchkhal Municipality of Kavrepalanchok District in Central Nepal

Background: On September 2018, cluster of gastrointestinal cases following feast of Teej Festival was reported in Panchkhal Municipality of Kavrepalanchok, Nepal. The outbreak was investigated to identify the possible source of infection, causative agent and guide local control measures for prevention and control of the outbreak. Methods: Demographic and clinical details were collected from the cases, and the outbreak was described by time, place and person. Fourteen key informant interviews were conducted to assess the probable cause of infection, practice of food handling and preparation, source of drinking water. Semi-structured questionnaires were used to collect data from the cases. Blood examination, stool examination and culture and hepatitis serological test were done. Samples from wells and ponds were collected and microbiological tests were done in National Public Health Laboratory. Results: A total of 452 cases were identified with gastrointestinal illness and no reported deaths. All the affected population had taken food from the same place during the festival where children being more affected. Two stool samples detected Entamoeba Histolytica and some showed pus cells with no cyst or ova of organisms. Stool culture was negative. No definitive source of infection detected but was suspected to be due to improper food handling. Conclusion: This investigations confirmed the food borne outbreak in Panchkhal Municipality. The definitive causative agent of the foodborne outbreak was not identified. Proper and timely response to the outbreak is of utmost important, and can reduce the severity of the illness and halt further spread of the epidemics