Analytical Solution for MHD Flow of a Magnetic Fluid within a Thick Porous Annulus

The steady-state problem of a magnetic fluid filling a porous annulus between two cylindrical walls under the influence of a nonuniform radially outward magnetic field has been investigated. The cylindrical walls are either electrically perfectly insulated or electrically perfectly conducting. The permeability of the porous annulus increases with its radial location. The governing partial differential equations were derived carefully and closed form solutions for the profiles of the velocity component and the induced magnetic component were obtained. The effect of the strength of the externally applied magnetic field, the permeability of the porous annulus, and the conductivity of the cylindrical walls were examined through the angular velocity components, as well as the induced magnetic field

Experimental and Numerical Analysis of High-Resolution Injection Technique for Capillary Electrophoresis Microchip

This study presents an experimental and numerical investigation on the use of high-resolution injection techniques to deliver sample plugs within a capillary electrophoresis (CE) microchip. The CE microfluidic device was integrated into a U-shaped injection system and an expansion chamber located at the inlet of the separation channel, which can miniize the sample leakage effect and deliver a high-quality sample plug into the separation channel so that the detection performance of the device is enhanced. The proposed 45° U-shaped injection system was investigated using a sample of Rhodamine B dye. Meanwhile, the analysis of the current CE microfluidic chip was studied by considering the separation of Hae III digested ϕx-174 DNA samples. The experimental and numerical results indicate that the included 45° U-shaped injector completely eliminates the sample leakage and an expansion separation channel with an expansion ratio of 2.5 delivers a sample plug with a perfect detection shape and highest concentration intensity, hence enabling an optimal injection and separation performance

Heat transfer and fluid flow in rotating cylinders with a porous sleeve.

A finite difference method was employed in part three to obtain the flow and temperature fields in rotating cylinders with a porous sleeve. This configuration is identical to that in the second part, except that the inner cylinder rotates at a constant speed. The results obtained in this part cover all convection regimes.In the first part, the flow and temperature fields in rotating concentric or slightly eccentric cylinders with a porous sleeve were obtained using a perturbation method with the eccentricity ratio being the perturbation parameter.Based on these studies, it is concluded that the buoyancy effect promotes convection, but shear effect enhances shear flow and demotes convective flow. The flow strength decreases with the porous sleeve thickness. Consequently, viscous dissipation generates more heat. The permeability of the porous sleeve has the opposite effect of the sleeve thickness. The effect of thermal-conductivity ratio depends on the Rayleigh number. As the annulus becomes eccentric, large velocity and temperature gradients will occur at the narrowest clearance. The overall heat-transfer performance of an annulus with a porous sleeve mainly depends on the Rayleigh and Peclet numbers. The rotation of the inner cylinder delays the onset of natural convection.The second part deals with weak natural convection in a stationary concentric annulus with a porous sleeve. The inner cylinder is kept at a higher temperature than the outer cylinder. This study was performed using a perturbation method with the Rayleigh number being the perturbation parameter.This work investigates the flow and temperature distributions in rotating cylinders with a porous sleeve resulting from a combined effect due to shearing and thermal buoyancy. Other effects considered include the eccentricity of the inner cylinder, the permeability of the porous sleeve, its thickness and relative thermal conductivity with respect to the fluid layer. In general, this work consists of four parts.In the last part, a modified Hele-Shaw cell was used to visualize the flow patterns in a concentric rotating cylinder with a porous sleeve. A shaft was inserted through the Hele-Shaw cell that was filled with 50 cP silicone oil with suspended tracers

Proceedings of the 3rd International Conference on Community Engagement and Education for Sustainable Development

This proceeding contains articles on the various ideas of the academic community presented at The 3rd International Conference on Community Engagement and Education for Sustainable Development (ICCEESD 2022) organized by the Universitas Gadjah Mada, Indonesia on 7th-8th December 2022.  ICCEESD is a biannual forum for sharing, benchmarking, and discussing HEI’s activities in developing Education for Sustainable Development towards community engagement. Education for Sustainability as a teaching strategy for resolving community challenges through formal, informal, or non-formal education is expected to benefit from various community service best practices by academics, researchers, and students. The 3rd ICCEESD has “Strengthening Education for Sustainability Towards Better Community Engagement” as its theme this year. It is expected that the 3rd ICCEESD will provide a forum for the presenters and participants to exchange best practices, policies, and conceptual implementation of Education for Sustainability towards better community engagement and explore ideas to address community needs.  Conference Title: 3rd International Conference on Community Engagement and Education for Sustainable DevelopmentConference Theme: Strengthening Education for Sustainability Towards Better Community EngagementConference Acronyms: ICCEESD 2022Conference Date: 7th-8th December 2022Conference Location: Grand Rohan Jogja Yogyakarta, IndonesiaConference Organizer: Universitas Gadjah Mada, Indonesi