https://cyberleninka.org/article/n/403409.pdf

A review of numerical analysis of friction stir welding

In this paper, JIT (Just-In-Time)-KANBAN literature survey was carried out and presented. The introductory section deals with the philosophy of JIT, and the concept involved in the push and pull system. The blocking mechanisms in the kanban system are also discussed elaborately. Besides these sections, the importance of measure of performance (MOP) and the application of the same with respect to JIT-KANBAN are presented. The recent trends in the JIT-KANBAN are discussed under the heading “Special cases”. In this review, 100 state-of-art research papers have been surveyed. The directions for the future works are also presented.

Literature review of JIT-KANBAN system

Effect of welding processes on mechanical and microstructural characteristics of high strength low alloy naval grade steel joints

http://www.lib.kobe-u.ac.jp/repository/90002185.pdf

Analysis of effect of tool geometry on plastic flow during friction stir spot welding using particle method

Welding parameters like welding speed, rotation speed, plunge depth, shoulder diameter etc., influence the weld zone properties, microstructure of friction stir welds, and forming behavior of welded sheets in a synergistic fashion. The main aims of the present work are to (1) analyze the effect of welding speed, rotation speed, plunge depth, and shoulder diameter on the formation of internal defects during friction stir welding (FSW), (2) study the effect on axial force and torque during welding, (c) optimize the welding parameters for producing internal defect-free welds, and (d) propose and validate a simple criterion to identify defect-free weld formation. The base material used for FSW throughout the work is Al 6061T6 having a thickness value of 2.1 mm. Only butt welding of sheets is aimed in the present work. It is observed from the present analysis that higher welding speed, higher rotation speed, and higher plunge depth are preferred for producing a weld without internal defects. All the shoulder diameters used for FSW in the present work produced defect-free welds. The axial force and torque are not constant and a large variation is seen with respect to FSW parameters that produced defective welds. In the case of defect-free weld formation, the axial force and torque are relatively constant. A simple criterion, (a,tau/a,p)(defective) > (a,tau/a,p)(defect free) and (a,F/a,p)(defective) > (a,F/a,p)(defect free), is proposed with this observation for identifying the onset of defect-free weld formation. Here F is axial force, tau is torque, and p is welding speed or tool rotation speed or plunge depth. The same criterion is validated with respect to Al 5xxx base material. Even in this case, the axial force and torque remained constant while producing defect-free welds.

Internal defect and process parameter analysis during friction stir welding of Al 6061 sheets

Effect of process parameters on thermal history and mechanical properties of friction stir welds

Scheduling rules for dynamic shops that manufacture multi-level jobs

The problem of scheduling in dynamic shops is an important operational problem in view of its complexity and significance in terms of associated costs of scheduling. While a number of research studies have investigated the problem of scheduling in flow shops and job shops, only some attempts have been done to study the problem of scheduling in assembly job shops that manufacture multi-level jobs. The problem of scheduling in dynamic assembly job shops with jobs having weights for holding and tardiness of jobs deserves due attention. In this study an attempt has been made to propose new priority dispatching rules that minimize the performance measures related to weighted flowtime and weighted tardiness of jobs. The existing unweighted dispatching rules have been modified in view of the consideration of weights for flowtime and tardiness of jobs. The performances of the (modified) existing dispatching rules and the proposed dispatching rules are compared through exhaustive simulation experiments with the consideration of a number of different experimental settings involving due-date setting, utilization levels and types of job structures. The proposed dispatching rules are found to perform better than the existing ones in most experimental settings and with respect to a number of measures of performance.

Performance evaluation of priority dispatching rules in multi-level assembly job shops with jobs having weights for flowtime and tardiness

Micro LEDs may be placed on a substrate in regularly spaced rows with an empty row between at least two successive rows of micro LED. A micro solar cell may then be placed in the empty row.

Micro Solar Cell Powered Micro LED Display

Sliding inguinal hernias present with various symptoms and these are usually direct inguinal hernias containing various abdominal viscera.  Case reports and series have been published with various organs and rare organs being part of the hernia.  Urinary bladder is a known content of sliding hernias.  This case report emphasizes this aspect in a picturesque manner and the importance of radiological investigations for pre-surgical evaluation.

http://www.radiologycases.com/index.php/radiologycases/article/download/91/pdf

K. Natarajan

Papers

Effect of process parameters on thermal history and mechanical properties of friction stir welds

Scheduling rules for dynamic shops that manufacture multi-level jobs

Performance evaluation of priority dispatching rules in multi-level assembly job shops with jobs having weights for flowtime and tardiness

Micro Solar Cell Powered Micro LED Display

Cystogram with dumbbell shaped urinary bladder in a sliding inguinal hernia.