Nanoparticle shape and thermal radiation on Marangoni Water, Ethylene Glycol and Engine Oil Based Cu, Al2O3 and SWCNTs

The aim of this paper is to investigate the relationship between particle shape and radiation effects on Marangoni boundary layer flow and heat transfer of water, ethylene glycol and engine oil based Cu, Al2O3 and SWCNTs. There are three types of nanoparticle shapes are considered in this research such as sphere, cylinder and lamina. The governing nonlinear partial differential equations are reduced into a set of nonlinear ordinary differential equations by applying similarity transformation which is solved using shooting technique in conjunction with Newton’s method and Runge Kutta algorithm. Temperature profiles are graphically and tabularly provided for the effects of solid volume fraction parameter, radiation parameter and empirical shape factor. The result shows that solid volume fraction and radiation energy gives a good impact on thermal boundary layer. Sphere nanoparticle shape predicts a better result on heat transfer rather than other nanoparticle shapes

Hypothesis testing for the parameters of log-logistic regression model with left-truncated and right-censored survival data

Left-truncation and right-censoring (LTRC) arise naturally in lifetime data. Data may be left-truncated due to a limitation in the study design. Failure of a unit is observed only if it fails after a certain period. Usually, the units under study may not be followed until all of them have failed but the study has to be stopped at a certain time. This introduces the right censoring into the survival data. Log-logistic model is extended to accommodate the left-truncated and right-censored survival data. The bias, standard error (SE), and root mean square error (RMSE) of the parameter estimates are computed to evaluate the performance of the model at different sample sizes, censoring proportion (CP), and truncation level (TL). The results show that the SE of the parameter estimates increase as the truncation level (TL) and censoring proportion (CP) increase. Having low and high TL (5% and 15%) in the data, the graphs clearly show that the empirical power of both tests increases with the increase of TL for parameter and . The SE and RMSE also decrease as the sample size increases. Following that, power analysis is conducted via simulation to compare the performance of hypothesis tests based on the Wald and Likelihood Ratio (LR) for the parameters. The results clearly indicate that the Wald performs slightly better than the LR when dealing with the proposed model

Association between prevalence of work-related musculoskeletal disorders and work-related ergonomic factors of special education teachers in Kota Bharu, Kelantan

Work-related musculoskeletal disorders (WMSDs) have become increasingly common among health-related professionals, including special education personnel who serve students with disabilities; however, WMSDs have been overlooked in this population. This study was conducted to investigate the association between the prevalence of WMSDs and work-related ergonomic factors among special education teachers in Kota Bharu, Kelantan. WMSDs questionnaires with three domains were used in this cross-sectional study involving 103 special education teachers. Result: Approximately 72% of the 103 special education teachers experienced musculoskeletal disorders. The lower back, shoulder and neck were the three most affected regions. Results revealed that assisting in diaper changing (p=0.011) and toileting (p=0.007), having no teaching partners (p=0.046), no nap habit (p=0.001) and duration of working experience >5 years (p=0.001), were strongly associated with the prevalence of WMSD. The present study revealed an association between WMSDs and work-related ergonomic factors among special education teachers. Future efforts should emphasize on measure to reduce high prevalence of WMSDs among this group, in order to improve their health status and avoid harmful impact on their personal and working productivity

Lorentz Forces And Nano Particle Shapes On Water, Ethylene Glycol And Engine Oil Based Cu, Al2o3 And Swcnts

This paper investigates the effect of nanoparticle shapes on MHD water, ethylene glycol, engine oil based Cu, Al2O3 and SWCNTs over a stretched plate includes concern of thermal radiation. The aim is to examine the influence of various nanoparticle shapes such as sphere, cylinder and lamina on the performance of heat transfer in the presence of water, ethylene glycol, engine oil based Cu, Al2O3 and SWCNTs by using numerical approach. Similarity transformation is used to transform the governing partial differential equations (PDEs) into ordinary differential equations (ODEs) which then are analyzed numerically by shooting technique coupled with Runge Kutta Fehlberg method in MAPLE18 software. Simultaneous effects of magnetic, velocity ratio parameter, radiation, temperature index and volume fraction of nanoparticle are demonstrated graphically. Analysis of nanoparticle shapes reveal that sphere shape plays a dominant role to enhance rate of heat transfer and increase temperature distribution of nanofluid with enhancing of magnetic, thermal radiation, volume fraction while temperature distribution reduces with increasing of velocity ratio and temperature index values

Electric field strength on water based aluminum alloys nanofluids flow up a non-linear inclined sheet

Nanoparticle shapes on radiative MHD water based aluminum alloy nanoparticles, AA7072 and AA7075 flow up a non-linear wall with distinct flow condition is analyzed. The three absolute pattern of nanoparticle shapes is enlisted into transcript, i.e. cylinder, sphere and lamina. The system of equations (ODEs) is resolved generally by running R.K Fehlberg method, MAPLE 18. Thermal energy film of the sphere shape particles of AA7075 – water is notably higher than another configuration in the flow regime