Numerical Simulation of Nanoparticles with Variable Viscosity over a Stretching Sheet

The effects of different types of base fluids on carbon nanotube (CNT) nanofluids flow over a circular stretching sheet are numerically analyzed. The nonlinear variation of radial velocity in radial direction is assumed at surface of stretching sheet. The temperature dependent fluid viscosity is taken into consideration. Two different types of flows (assisting flow and opposing flow) are discussed under the buoyant force effects. Single walled CNT and multi walled CNT are considered as nanoparticles for better thermal conductivity of the nanofluids. A set of similarity transformations to convert the partial differential equations into ordinary differential equations is hired. The non-linear ODEs are numerically solved by employing fourth order Runge-Kutta method. Discussions of numerical simulations for flow characteristics have been made appropriately. A comparative study for various type of base fluids like kerosene, engine oil and ethylene glycol is also presented. From the predicted simulation, it is observed that the variation in Nusselt number is maximum for engine oil and minimum for kerosene oil however, the variation in skin friction coefficient is largest for kerosene oil and least for engine oil. Furthermore, numerical results are also validated with achieving a good correlation with existing results

Cattanneo-Christov Heat Flux Model Study for Water-Based CNT Suspended Nanofluid Past a Stretching Surface

This chapter discusses the magnetic field effects on the flow of Cattanneo-Christov heat flux model for water-based CNT suspended nanofluid over a stretching sheet. According to the authors, knowledge idea of Cattanneo-Christov heat flux model for water-based CNT suspended nanofluid is not explored so far for stretching sheet. The flow equations are modeled for the first time in the literature transformed into ordinary differential equations using similarity transformations. The numerical solutions are computed using shooting technique and compared with the literature for the special case of pure fluid flow and found to be in good agreement. Graphical results are presented to illustrate the effects of various fluid flow parameters on velocity, heat transfer, Nusselt number, Sherwood number, and skin friction coefficient for different types of nanoparticles

Numerical study of Williamson nano fluid flow in an asymmetric channel

AbstractThis article investigates with the peristaltic flow of a Williamson nano fluid in an asymmetric channel. The related modeling of the problem has been done in Cartesian coordinate system. Problem has been simplified with the reliable assumptions i.e. long wave length and small Reynolds number. Numerical solutions have been evaluated for stream function, velocity profile, temperature profile, nano particle phenomena and pressure rise. Graphical results have been presented and discussed for various involved parameters

Zooplankton composition and structure in the Indus River Estuary, Sindh, Pakistan

In this study abundance and composition of zooplanktons in the Indus River Estuary was conducted to examine habitat characteristics and its impact on tiny organisms. Overall 30,656 individuals were identified and segregated into seven major groups including Copepods, Cnidarians, Decapods, Mollusk, Pisces, Amphipods and Chaetognaths. For better understanding they were further divided into eighteen planktonic categories. Among them Lucifer spp. comprises of 52.21% was the most abundant group with a peak appeared in March whereas Chaetognaths were rarely observed in the entire study period. Species diversity exhibited a mixed trend with the highest values (0.776) of dominance observed in spring (March). The results of Canonical Correspondence Analysis (CCA) indicate (60.2% and 39.79%) variability among first II axis. On this basis of the result it is obvious that water turbidity is trigger of the abundance and distribution whereas total dissolved solids (TDS) showed minimal influence deduced from CCA analysis

Evaluación de concentraciones de macrominerales en sangre de vacas Desi lactantes y secas

Objective. This study was conducted during winter season at rural livestock farm of district Sargodha, Pakistan, in order to define the macrominerals status in blood plasma of lactating and dry Desi breed cows. Material and methods. Twenty lactating and twenty dry cows were used and their blood plasma was analyzed for Ca, Mg, Zn, Cu and Fe using atomic absorption spectrophotometer. Results. In lactating cows, the plasma Ca concentration was lower than dry cows (6.8 vs. 7.6 mg/dl, p<0.001), while Mg concentration was similar between lactating and dry cows. Plasma Zn concentration in lactating cows was higher than dry cows (0.78 vs. 0.60mg/l, p<0.01) and it resulted lower than the normal range in both groups. Plasma Cu level in lactating cows was lower than dry cows (0.56 vs. 0.76 mg/L, p<0.001) and it was lower than the normal range only in lactating cows. Lactating cows resulted in higher plasma Fe concentration compared to dry cows (3.8 versus 2.6 mg/L; p<0.01). Conclusions. From our findings, it can be concluded that the observed minerals level meets the needs of ruminants and the plasma level of different minerals is affected by the physiological stages of cows.201

Bioconcentration of some macrominerals in soil, forage and buffalo hair continuum: A case study on pasture irrigated with sewage water

AbstractThe present study aimed to evaluate the bioaccumulation of some macrominerals in grazing buffaloes fed forage irrigated with sewage water or canal water. In particular, the transfer of sodium (Na), magnesium (Mg), potassium (K) and calcium (Ca) from soil to plant and in turn to animals was evaluated under sub-tropical environmental conditions. Samples of soil, forage and buffalo hair were collected and digested by wet method. Sodium and K concentrations were significantly higher in the soil but lower in the forages; however, Mg and Ca concentrations in both soil and forages were higher. The correlation between soil, forage and hair showed an imbalanced flow of Na, Mg and K and a balanced flow of Ca from soil to forage and then to animals. Based on the findings, the highest rates of transfer of minerals were found for sewage water treatment, whereas lowest rates were found for canal water treatment, except for Na. As the transfer of minerals depends on their bioavailability, the highest values may be due to the high rates of mineral uptake by plants. Thus, the high transfer rate of some elements by plants could become toxic in future causing detrimental effect to grazing livestock

Dengue Outbreaks in Khyber Pakhtunkhwa (KPK), Pakistan in 2017: An Integrated Disease Surveillance and Response System (IDSRS)-Based Report

Snažni bočni vjetrovi koji pušu na mostovima i vijaduktima mogu dovesti do gubitka dinamičke stabilnosti vozila koja prelaze most. Da bi se omogućio nesmetan i siguran promet čak i u slučajevima nepovoljnih vremenskih uvjeta uzrokovanih snažnim bočnim vjetrom, na mostove se postavljaju zaštitni vjetrobrani. Karakteristike strujanja zraka preko mosta su značajno promijenjene u slučaju postavljanja vjetrobrana različitih visina i poroznosti. U okviru ovog rada ispitan je utjecaj visine vjetrobrana te utjecaj poroznosti vjetrobrana na karakteristike strujanja zraka oko vozila koje se nalazi na mostu. Vjetrobran je postavljen samo na uzvodni rub mosta, a za vozilo je korišten model Ahmedovog tijela koji je u svim simulacijama postavljen na udaljenost 2 m nizvodno od vjetrobrana. Pri računalnim simulacijama korišten je model stacionarnog trodimenzijskog turbulentnog strujanja nestlačivog fluida te k-ω SST model turbulencije sa standardnim zidnim funkcijama. Dobiveni rezultati ukazuju na značajan utjecaj vjetrobrana na koeficijente tlaka na površini vozila. Manja poroznost vjetrobrana i veća visina vjetrobrana uzrokuju smanjenje koeficijenta tlaka na nastrujavanoj površini vozila. Iako su vrijednosti koeficijenta tlaka na površini vozila za male poroznosti vjetrobrana relativno male, raspodjela vrtložnosti struje zraka sugerira da može doći do povećanih vrijednosti standardnih devijacija aerodinamičkih sila koje djeluju na vozilo. Karakteristike vjetrobrana imaju bitan utjecaj na raspodjelu brzine strujanja zraka uzvodno od vozila, odnosno u prostoru između vjetrobrana i vozila. Smanjenjem poroznosti vjetrobrana se brzine strujanja zraka u tom području značajno smanjuju. Utjecaj poroznosti vjetrobrana na raspodjelu brzine strujanja zraka u ovom području je značajniji u odnosu na utjecaj visine vjetrobrana. Aerodinamičke sile i momenti zabilježeni na vozilu su značajno smanjeni kada je vjetrobran postavljen na most. Rezultati dobiveni u okviru ovog rada sugeriraju da je, s obzirom na aerodinamičke sile koje djeluju na vozilo, optimalna visina vjetrobrana 5 m uz njihovu poroznost u iznosu od 30%.Strong cross winds that commonly blow on bridges and viaducts may cause dynamic instabilities of vehicles crossing the bridge. To allow for safe traffic even in the periods of bad weather conditions such as strong cross winds, bridges are equipped with wind barriers. Flow characteristics around the bridge are significantly modified with respect to the wind barrier height and porosity. In the present work, the influence of wind barrier height and porosity on flow characteristics around the vehicle passing the bridge was studied. The wind barrier was placed on the windward bridge-deck edge only, while the Ahmed body was used as a vehicle. It was placed 2 m downwind of the wind barrier. In the computational simulations, the stationary 3D turbulent incompressible flow was modeled together with the k-ω SST turbulence model and standard wall functions. The obtained results generally show a significant influence of the wind barrier on the pressure coefficients observed on the vehicle surface. Smaller porosity and larger height of the wind barrier causes smaller pressure coefficients on the windward side of the vehicle. Even though the pressure coefficients on the vehicle for the low-porous wind barrier are relatively small, the distribution of the flow vorticity suggests larger values of the standard deviation of the aerodynamic forces acting on the vehicle. Wind-barrier characteristics proved to have a large influence on the distribution of flow velocity in the area upstream of the vehicle and downstream of the wind barrier. For smaller porosities of the wind barrier, flow velocities in this area are significantly smaller. The influence of the porosity on the distribution of flow velocities in this area is relatively larger compared to the height of the wind barrier. The aerodynamic forces and moment are generally smaller when the wind barrier is in place. The obtained results suggest that the 5 m high and 30% porous wind barrier is optimal with respect to the aerodynamic forces and moment acting on the vehicle on the bridge

Evaluation of macrominerals concentrations in blood of lactating and dry Desi cows

ABSTRACTObjective. This study was conducted during winter season at rural livestock farm of district Sargodha, Pakistan, in order to define the macrominerals status in blood plasma of lactating and dry Desi breed cows . Material and methods. Twenty lactating and twenty dry cows were used and their blood plasma was analyzed for Ca, Mg, Zn, Cu and Fe using atomic absorption spectrophotometer. Results. In lactating cows, the plasma Ca concentration was lower than dry cows (6.8 vs. 7.6 mg/dl, p&lt;0.001), while Mg concentration was similar between lactating and dry cows. Plasma Zn concentration in lactating cows was higher than dry cows (0.78 vs. 0.60mg/l, p&lt;0.01) and it resulted lower than the normal range in both groups. Plasma Cu level in lactating cows was lower than dry cows (0.56 vs. 0.76 mg/L, p&lt;0.001) and it was lower than the normal range only in lactating cows. Lactating cows resulted in higher plasma Fe concentration compared to dry cows (3.8 versus 2.6 mg/L; p&lt;0.01). Conclusions. From our findings, it can be concluded that the observed minerals level meets the needs of ruminants and the plasma level of different minerals is affected by the physiological stages of cows.RESUMENObjetivo. Este estudio se realizó durante la estación de invierno en la granja de ganado rural del distrito de Sargodha, Pakistán, con el fin de definir el estado de macrominerales en el plasma sanguíneo de vacas lactantes y secas de raza Desi. Materiales y métodos. Veinte vacas lactantes y veinte vacas secas fueron utilizadas y se analizó el plasma para el Ca, Mg, Zn, Cu y Fe utilizando un espectrofotómetro de absorción atómica. Resultados. En las vacas lactantes, la concentración de Ca en plasma fue menor que en las vacas secas (6.8 frente a 7.6 mg/dl, p&lt;0.001), mientras que la concentración de Mg fue similar entre las lactantes y las vacas secas. La concentración plasmática de Zn en las vacas lactantes fue mayor que en las vacas secas (0.78 frente a 0.60 mg/L, p&lt;0.01) y resultó inferior al rango normal en ambos grupos. Nivel de plasma de Cu en vacas lactantes fue inferior al de las vacas secas (0.56 vs a 0.76 mg/L, p&lt;0.001) y fue inferior al rango normal sólo en las vacas lactantes. Las vacas lactantes resultaron en mayor concentración de Fe plasmático en comparación con las vacas secas (3.8 frente a 2.6 mg/l, p&lt;0.01). Conclusiones. A partir de los resultados, se puede concluir que el nivel de minerales observados satisface las necesidades de los rumiantes y el nivel plasmático de diferentes minerales se ve afectado por las etapas fisiológicas de las vacas