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•Analysis of deposition of engine parts.•Particulate matter emissions.

ABSTRACTThe global spread of English has induced an unrivaled growth of local varities of English. The study aimed to explore Pakistani university students’ attitudes toward the Pakisani, British, and American varieties of English concurrently. A mixed methods explanatory sequential design was used. Initially, 100 university students were recruited for data collection in the first quantitative phase. The researchers employed a verbal guise test/survey for the phase. The phase was followed by 8 semi-structured interviews in the later qualitative part. The interview participants were sampled purposively from the first phase to ensure maximum variation. The quantitative results displayed that the participants had positive attitude toward the British English, moderate attitudes toward the Pakistani English, and negative attitudes toward the American English. However, the qualitative findings revealed that some of the participants had highly positive attitudes toward Pakistani English. The study recommends the development of a comprehesive sociolinguistic framework to promote the pluralistic model of world Englishes.

Purpose: The purpose of study is to examine the dual nature of the branches for the problem of Darcy–Forchheimer porous medium flow of rotating nanofluid on a linearly stretching/shrinking surface under the field of magnetic influence. The dual nature of the branches confronts the uniqueness and existence theorem, moreover, mathematically it is a great achievement. For engineering purposes, this study applied a linear stability test on the multiple branches to determine which solution is physically reliable (stable). Design/methodology/approach: Nanofluid model has been developed with the help of Buongiorno model. The partial differential equations in space coordinates for the law of conservation of mass, momentum and energy have been transformed into ordinary differential equations by introducing the similarity variables. Two numerical techniques, namely, the shooting method in Maple software and the three-stage Lobatto IIIA method in Matlab software, have been used to find multiple branches and to accomplish stability analysis, respectively. Findings: The parametric investigation has been executed to find the multiple branches and explore the effects on skin friction, Sherwood number, Nusselt number, concentration and temperature profiles. The findings exhibited the presence of dual branches only in the case of a shrinking sheet. Originality/value: The originality of work is a determination of multiple branches and the performance of the stability analysis of the branches. It has also been confirmed that such a study has not yet been considered in the previous literature. [ABSTRACT FROM AUTHOR]

Machining is material removal from a workpiece. Current spindle technologies allow the material to be removed very quickly but unfortunately this compromises the accuracy of the desired machined trajectory on the workpiece. Proposed solution to the problem is restricting motion of the tool and giving rotation to the workpiece. This paper presents analysis of the accuracy of trajectory of material removal from a workpiece, such that the workpiece rotates with six degrees of freedom, in the presence of error generated due to an offset of the workpiece from centre of the moving platform of the machining bed. The kinematics of the machining bed is, therefore, modeled using as inverse kinematic formulation applying geometric and vector addition method. The mechanism outputs three rotational and three translational motions. The leg length for each of six legs of the bed is computed individually. Moreover, workpiece position offset error is modelled to find actual leg lengths of the bed. Finally accuracy computation model is proposed to analyse the accuracy of the final trajectory of the motion of the workpiece. The models are verified in simulation for a trajectory and validated experimentally on a six degree of freedom (6DOF) machining bed. The results reveal maximum inaccuracy in machining trajectory to be 1% in experiments while less than 1% in simulation. This verifies quality of the mechanism and efficacy of the proposed 6DOF machining bed in machining accuracy.

Mr. President, honorable members of the Senate, in welcoming me within these walls and giving me an opportunity of addressing this august assembly, you have bestowed upon me high prerogative [...]

The ecological and economical concerns have given rise to the application of solar photovoltaic (PV) system in the community to meet the increased load demands on its own. Owing to the varying output of solar PV modules depending on the weather conditions, the efficiency of system is degraded and thus requires using maximum power point (MPP) tracking technique for utmost power extraction. The MPP methods can be realized both mechanically or electrically using suitable converter topology and appropriate tracking algorithm. However, the mechanical tracker in contrast to electrical circuit is immoderate and inefficient and conversely necessitates to exercise effective and promising power tracking algorithm. This research proposes to implement the perturb and observe (Pand O) algorithm for MPPT in charge controller using buck–boost converter to attain desired and optimized results. The use of buck–boost DC–DC converter helps in stepping up/down the voltage level as per requirements under the control of Pand Oalgorithm. Having optimized tracker designed, its performance has been tested at different levels of irradiance and temperature principally with load and battery. Further, the results obtained from simulated scenarios are compared with real-time experiments, which confirm the robustness and effectiveness of proposed MPPT method in solar PV system using Pand Oalgorithm and buck–boost converter.

Researchers are using different types of nanomaterials for the enhancement of the thermal performance of regular fluids such as water, kerosene oil, etc. However, these days, the researchers are more interested in hybrid nanomaterials. The purpose of this communication is to examine the stability analysis of Cu–Al2O3/water hybrid nanofluid over a non-linear shrinking sheet. The hybrid nanomaterials are composed of Cu and Al2O3. These hybridized nanomaterials are then dissolved in water taken as base fluid to form Cu–Al2O3//water hybrid nanofluid. Mathematical analysis and modeling have been attended in the presence of viscous dissipation and suction/injection effects. The governing equations of mathematical models are transformed into self-similar solutions in the form of ODEs by using similarity transformation. Solutions of the non-linear ODEs are created by employing of three-stage Lobatto IIIa formula which is built-in BVP4C function in the MATLAB software. A comparison of the current study has been done with the preceding published literature. The distributions of velocity, temperature profiles, coefficient of skin friction and heat transfer rate are presented graphically and conferred for numerous significant parameters entering into the problem. Results revealed the existence of dual solutions for a certain range of the suction/blowing parameter. Stability analysis is also done in order to obtain dual solutions stability. The smallest eigenvalues suggest that the first solution is stable from the second solution. Hybrid nanomaterials have a high scope toward nurturing our day-to-day life.

A computational study of Casson sodium alginate–hybrid nanofluid of stagnation point flow through a shrinking/stretching cylinder with radius effect was carried out. Since the hybrid nanofluid is considered more contemporary type of nanofluid, it is currently being employed to enhance the efficiency of heat transmission rates. The aim of this study is to scrutinize the effect of particular parameters, such as the shrinking parameter, the Reynold number, the Casson fluid parameter, the solid copper volume fraction, and the Prandtl number, on the temperature and velocity profiles. Furthermore, the research looked into the variation of skin friction coefficient as well as the Nusselt number according to the Casson fluid parameters, and the copper solid volume fraction against shrinking parameter was investigated as part of this study. By including the appropriate similarity variables in the alteration, the nonlinear partial differential equation has been transformed into a set of ordinary differential equations (ODEs). In the end, the MATLAB bvp4c solver program is used to rectify ODEs. The findings revealed the existence of two solutions for shrinking surface with varying copper volume fractions and Casson fluid parameter values. Furthermore, the temperature profile rate was reduced in both solutions as the strength of the Reynold number, Casson fluid parameter, and copper volume fraction increased. Finally, non-unique solutions were obtained in the range of λ≥λci\lambda \ge {\lambda }_{{\rm{ci}}}.

The current investigation aims to explore multiple solutions for the three-dimensional flow of nanoliquid composed of CNTs/C2H6O2+H2Oover a surface that either shrinks or stretches within a rotating frame. The impacts of a magnetic field and thermal radiation have also been considered into account. In the exploration, the two primary categories of carbon nanotubes have been focused: multi-walled (MWCNT) and single-walled (SWCNT). The primary solvent selected for this study is represented by the formula C2H6O2+H2O. The boundary layer approximations play a crucial role in this study as they facilitate the transformation of the governing partial differential equations (PDEs) into more manageable ordinary differential equations (ODEs). To tackle these ODEs and obtain numerical solutions for the underlying flow issues, the shootlib function embedded in the Maple program has been utilized. The conducted parametric study, designed to uncover various solutions and explore their effects on Nusselt number, skin friction, velocity, and temperature profiles. It is observed from the current analysis that, the skin friction experienced a notable increase of 32.5% in magnitude when the rotation parameter was raised from 0 to 1. The first solution exhibits an increase of 8.5% for single-walled carbon nanotubes (SWCNTs) and 9.5% for multi-walled carbon nanotubes (MWCNTs) when the volume fraction is changed from 2.3 to 2.4. The findings of the current study hold promise for improving thermal management systems in aerospace engineering and optimizing cooling processes in environmental engineering applications.

This study employs the Tiwari and Das model to numerically evaluate the heat-transfer properties of a magnetized Casson sodium alginate-copper/alumina hybrid nanofluid flow over a permeable moving surface, taking into account the effects of viscous dissipation. Sodium alginate-alumina/copper hybrid nanofluids have garnered significant attention in modern society because of their potential uses in a variety of different industries. The key goal of the study is to examine the effect of the Casson parameter and copper solid volume fraction for skin friction coefficient and Nusselt number against velocity ratio parameter. Additionally, in the present study, velocity and temperature profiles for velocity ratio parameter, suction effect, magnetic parameter, Eckert number, and Prandtl number are also included. Using the bvp4c technique, the PDEs are converted into a set of non-linear ODEs with the use of suitable similarity variables. Dual approaches for controlling parameter using varied Casson fluid parameter and copper solid volume fraction quantities have been identified. Unique solutions, no solutions, and dual solutions exist in specific ranges of parameters. Consequently, beyond the critical values, no solution exists. The rate of heat transfer strengthened as the capacity of the Eckert number augmented. The temperature profile also diminished when the Prandtl number improved. The appearance of the boundary layer separation extension resulted from incorporating the copper solid volume fraction. Finally, stability analysis reveals that the first solution is stable, and the second solution is unstable.

There has been a lot of interest in alternative fuels due to the depletion of petroleum supplies and growing environmental concerns. Biodiesel is made from renewable resources and is one of the many practical and beneficial fuel substitutes for fossil fuels. Recent advancements in nanotechnology have made it feasible to use nanoparticles as fuel additives for internal combustion engines. An earlier study suggested that these compounds might enhance engine performance. There has been a concern that this may increase the particulate matter emitted with the exhaust which adversely affects the air quality. The size-distribution of unregulated particulate matter (PM) emitted with exhaust gases is examined in this work. Under various load conditions, PM exhaust emissions were examined while keeping the engine running at a constant 1350 rpm. A nanoparticles of 50 parts per milligram of Aluminum oxide Al2O3and Iron oxide Fe2O3into the jatropha biodiesel / diesel fuel blend. When the engine is fueled with blend of diesel, biodiesel, and nanoparticles ternary fuel, it created fewer particulate matter emissions than the diesel/biodiesel binary blend which contains no nanoparticles. In comparison to pure diesel fuel, the diesel/biodiesel blend binary combination produced 10-15% less PM1, PM2.5, PM7, and PM10 emissions which is very critical to air pollution problem with the fine/very fine particles.

Alternative fuels have garnered significant attention due to the depletion of petroleum sources and growing environmental concerns. Biodiesel, a renewable fuel, holds potential as a viable substitute for fossil fuels. Recent advancements in nanotechnology have made nanoparticle fuel additives for internal combustion engines feasible. Previous research has shown that these additives can enhance engine performance. In this experimental study, we investigated the effects of incorporating aluminium oxide nanoparticles (Al2O3) into a JB30 fuel blend (30% Jatropha biodiesel + 70% diesel) to assess potential performance improvements and reduced noise emissions. Our tests employed a 4-stroke, single-cylinder diesel engine operating at a constant speed of 1350 rpm. The JB30 blend was subjected to a 50 ppm dose of Al2O3nanoparticles using an ultrasonicator. Results indicate that brake-specific fuel consumption (BSFC) improved for the DF70JB30 blend and further improved for the DF67JB30 blend with Al2O3nanoparticles. Compared to pure diesel fuel, the brake thermal efficiency (BTE) increased by 3.77% for DF70JB30 and by 3.82% for DF67JB30Al2O3. Noise emissions, a crucial factor influenced by the fuel type, were lower for all blended fuels compared to pure diesel fuel (DF). The addition of nanoparticles also contributed to a reduction in the combustion pressure rise rate, resulting in decreased combustion noise. Based on these findings, it can be concluded that both the binary blend DF70JB30 and the ternary blend DF67JB30Al2O3can be used in diesel engines without necessitating any adjustments. However, DF67JB30Al2O3demonstrated superior outcomes when compared to DF70JB30.

The thermal stability of nanomaterials is quite necessary for controlling the heat and cooling phenomenon. It is worthy observed that much research has been focused scientists towards the thermal significance of nanoparticles with multidisciplinary engineering and industrial applications. On this end, this report explores the improved thermal mechanism water base material with interaction of hybrid nanofluid stretching and shrinking surface. The cooling and heat phenomenon is observed in presence of viscous dissipation. The hybrid nanofluid characteristics are inspected with combination of copper (Cu)and aluminum oxide (Al2O3)nanoparticles with stable prospective. The consideration of such hybrid nanoparticles is due to impressive thermal characteristics and stable thermal performances. Although some studies are focused by researchers on hybrid nanofluid, however the measurement of thermal stability is not claimed yet. The stretching and shrinking configuration specify the porous medium features. The problem is compiled into dimensionless structure which is further preceded via bvp4c scheme. The resultant ODEs are successfully numerically solved using the bvp4c solver technique. Under restricting conditions, numerical findings are compared to previously published results. Non-dimensional profiles of velocity and temperature are shown graphically. Furthermore, graphs and tables show the effects of the physical parameters used on the reduced skin friction and heat transfer rate. Dual branches are found in specified domain of suction factor.

Evidence is sparse about the genetic determinants of major lipids in Pakistanis.

Ethyl chloroformate was examined as a precolumn derivatizing reagent for the gas chromatographic (GC) determination of isoniazid (INH) and hydrazine (HZ). Phenylhydrazine (PHZ) was used as an internal standard. GC separation was carried out on an HP-5 column (30 m × 0.32 mm i.d.) with flame ionization detection. The elution was carried out at an initial column temperature of 150°C for 1 min at a heating rate of 10°C/min up to 250°C, nitrogen flow rate of 4 ml/min and a split ratio of 10:1, v/v. The linear calibration ranges for INH and HZ were observed between 3.5–37.5 and 3.5–35 mg/ml with corresponding detection limits of 0.18 and 0.17 ng reaching the detector. The method was subsequently applied to the determination of INH and HZ in pharmaceutical preparations, achieving a relative standard deviation (RSD) of 3.8–5.8%. The recovery percentage of INH from isoniazid syrup was 98% with an RSD of 5.2%.

This paper gives a brief overview of modern ultrasonic inservice inspection techniques using a phased-array system. Experimental results on the application of the system in the nuclear field are discussed, especially the measurements carried out on geometries which are complicated in relation to the ultrasonic inspection. These are, for instance, the spherical bottom or dome of nuclear pressure vessels or the inner nozzle radius. In order to solve this inspection problem it must be considered also that there is a very reduced accessibility for the ultrasonic probes. Further, the principle of the data acquisition and evaluation is described.

AbstractThe effect of operating cycle and fuel burnup on the isotopic composition and decay characteristics of irradiated nuclear fuel has been investigated using a standard computer code, KORIGEN. The parameters studied include isotopic compositions of actinides; activities due to the actinides, fission products, and light elements; decay heat; and the spontaneous fission neutron source. Calculations have been performed for a typical swimming pool-type research reactor, using materials test reactor-type low-enriched uranium fuel, for four different operating cycles. A fuel burnup range of 5 to 35% has been considered. The cooling time ranged from a fraction of a second to thousands of years. Results indicate that the amount of plutonium produced is strongly dependent on fuel burnup. It is not significantly affected by the operating cycle. The operating history of the reactor has a strong influence on fission product inventory and decay heat. The main contributors to activity and decay heat for the first two to three centuries are fission products; thereafter, actinides are the main contributors. The activity and decay heat drop drastically during the first day after shutdown. Both alpha activity and the spontaneous fission neutron source are strongly dependent on the operating cycle and fuel burnup. These increase with an increase in the fuel burnup but decrease for a longer power-on cycle.

•CSP potential in China is evaluated based on natural and human resources.•Current status of CSP around the globe and in particularly China is reviewed.•A SWOT analysis is carried out to analyze the strengths, weaknesses, opportunities and threats of CSP in China.•Recommendations are proposed from the outcomes of SWOT analysis for development of CSP in China.