Dispersion of a solute in a Herschel–Bulkley fluid flowing in a conduit

The dispersion of a solute in a Herschel-Bulkley fluid is studied by using the generalized dispersion model in both pipe and channel. With this method the entire dispersion process is described as a simple diffusion process with the effective diffusion coefficient as a function of time. The results for Newtonian fluid, power law fluid and Bingham fluid are obtained as special cases by giving appropriate values to the power law index and yield stress. The effects of power law index, yield stress on the dispersion coefficient and mean concentration have been discussed computationally and graphically. The effect of power law index and yield stress is found to reduce the dispersion coefficient. It is observed that the critical time for dispersion coefficient to reach the steady state is varying with the yield stress and power law index. It is noticed that time to assume the critical value in Newtonian case is 0.5 and in the channel case the corresponding value of time is 0.55 which are in agreement with the existed results. It is also observed that in the non- Newtonian fluids this time is less than that of Newtonian fluid case and in Bingham fluid the critical value of time in pipe flow analysis (channel flow analysis) is attained at 0.45 (0.52) while in power law fluid it is at 0.43(0.48) and in the case of Herschel-Bulkley fluid it is 0.41 (0.45)

AN OVERVIEW OF INTEGRATED MEDICAL AND DENTAL UNDERGRADUATE PRE-CLINICAL CURRICULA AT B. P. KOIRALA INSTITUTE OF HEALTH SCIENCES, NEPAL: A MULTIPROFESSIONAL APPROACH

Curricular innovations such as multiprofessional education (MPE) sensitise health professionals towards the role of other health professionals and inculcate team spirit. This is a preliminary report on MPE in practice in the preclinical phase of dental and medical undergraduate courses at B.P. Koirala Institute of Health Sciences, Nepal. The preclinical curriculum of the undergraduate courseis integrated, organ system based and partially problem based. There is an emphasis on early exposure of students to patients and to community. The undergraduate course in medicine started in 1994 and in dental surgery in 1999 based on the core curriculum developed at various workshops. The course duration and structure is similar in bo

Development of eAgromet Prototype to Improve the Performance of Integrated Agromet Advisory Service

In several countries, the systems for forecasting weather are being operated to deal with weather and its related factors affecting agricultural production. India meteorological department (IMD) is providing several types of weather forecasts. One of the forecast service is medium range forecast (MRF). As a part of MRF, the expected values of rain fall, temperature, cloud cover, humidity, wind speed and wind direction for next five days are forecasted twice a week by considering district as a unit. Agriculture is markedly affected by weather condition during crop season. IMD in collaboration with Indian Council of Agriculture Research (ICAR) and State Agriculture Universities (SAUs) has set-up about 130 Agro-meteorological Field Units (AMFUs) and each AMFU covers about five districts. Based on MRF, IMD is rendering Integrated Agromet Advisory Service to the farming community of the country in the form of agromet advisory bulletin. The agromet advisory bulletins contain possible risk mitigation measures for the major crops and livestock. Based on the weather forecast, a group of interdisciplinary scientists and agromet scientists at AMFU prepare district-level agromet advisory bulletins. These bulletins are sent to the farmers and other stakeholders of the corresponding district. To ease the process of preparing agromet bulletins, an effort has started to build IT-based agrometeorological advisory system called, eAgromet. In this paper, we explain the concepts of eAgromet and its operation

On convection-diffusion in non-Newtonian fluid flow in an annulus with wall oscillations

Dispersion of a solute in a Casson fluid flow in an annulus is studied by considering the flow unsteadiness due to the pulsatile pressure gradient and wall oscillations. The expression for velocity is derived under the assumption of low Womersley frequency parameter and also yield plane locations are estimated. Generalized dispersion method is used to solve the convective diffusion equation and hence estimated the dispersion coefficient. With this approach mean concentration is able to express in terms of convection and dispersion coefficients. Effects of yield stress, unsteadiness of the flow, annular gap and wall oscillations on axial velocity, yield plane locations of the flow, dispersion coefficient and mean concentration are analysed. Due to combined action of wall oscillations and flow oscillations, the dispersion coefficient is observed to be changing cyclically and took both positive and negative values which differs from the case of no wall oscillations where the dispersion coefficient seen to be taking only positive values. Both qualitative and quantitative changes are seen in mean concentration in the case of wall movement when compared with the case of no wall oscillations

Dispersion with wall absorption in non-Newtonian fluid flow subjected to external body acceleration

The basic motive of this model is to understand the dispersion process of a solute in non-Newtonian fluid flow subjected to external body acceleration when taking into account the solute absorption at the tube wall. Generalized dispersion method approach is used and hence the local concentration is assumed as a series in terms of the mean concentration and its derivatives, with coefficients being functions of time. With this approach, the mean concentration is expressed in terms of three transport coefficients, namely the absorption, convection, and dispersion coefficients for the case of solute transfer at the wall. A finite-difference scheme is used to solve the intermediate equations in order to evaluate these transport coefficients. The effects of non-Newtonian rheology, pulsatile pressure gradient, external body acceleration, and the wall absorption on the dispersion coefficient and mean concentration are analysed. It is seen that the dispersion coefficient is affected by the presence of body acceleration as is evidenced by dramatic fluctuations in its magnitude during the course of the flow. We confirm that the peak of the mean concentration is dramatically reduced as the wall absorption coefficient increases, even in the presence of body acceleration. Based on the values of different parameters considered in the problem, the study can be applied to understand the dispersion phenomenon in narrow arteries

A PROSPECTIVE STUDY OF DENTAL DISEASE PATTERN AND DRUG UTILIZATION AT THE DENTAL DEPARTMENT OF A TERTIARY CARE TEACHING HOSPITAL IN EASTERN NEPAL

To find out the pattern of dental diseases and drug utilization at dental out patient department (OPD) of B.P. Koirala Institute of Health Sciences (BPKIHS), a tertiary care hospital. A prospective prescription audit was conducted for a period of 10 days in the dental OPD and the data was analyzed using WHO drug indicators. The total number of prescriptions analyzed were 279. Dental caries (37%), Periodontitis (14%) and chronic gingivitis (11%) were the most common diseases with a maximum incidence between the age groups of 9 to 40 years. Mean number of drugs per prescription was 2.79. Of the total prescriptions, 223 (79.9%) had 314 antimicrobial agents (AMA) constituting 40.3% of total drugs prescribed. The mean number of antimicrobial agents per prescription was 1.13. The most commonly prescribed antimicrobial agents was amoxycillin (33.1%) followed by metronidazole (24.9%), doxycycline (17.2%) and tinidazole (12.7%). Fixed dose drug combination of amoxycillin + cloxacillin (26) and ampicillin + cloxacillin (10) were prescribed in 36 of the prescriptions. Povidone iodine gargle (41.2%) was the most commonly prescribed oropharyngeal preparation followed by Chlorhexidine gluconate mouthwash (32.4%). Non- steroidal anti-inflammatory agents (20.66%), multi-vitamins (19.51%) and oropharyngeal preparations (17.45%) constituted the rest of the drugs prescribed. Diclofenac (60.86%) was the most commonly prescribed among NSAIDs and fixed dose drug combination of ibuprofen and paracetamol was prescribed in 19 of the prescriptions. All drugs were given by oral route (except for gentamicin in one prescription) and were prescribed under brand names. None of the prescriptions had instructions whether the drug should be taken before or after food. The results indicate that dental caries was the most common dental disease, anti-microbial agents were prescribed to majority of the patients and constituted a little less than half of the total drugs prescribed. Commonly used anti-microbial agent was amoxycillin which in two thirds of the cases was prescribed as an fixed dose drug combination. The high incidence of anti-microbial agent prescribing may be modified by a feedback to the prescribers. Key words: Dental morbidity, prescribing pattern, drug utilization, dental OPD, antimicrobial agents