Finite element analysis of fillet welded joint

T-joint fillet welding is the most common welding in engineering applications. Transport vehicles, marine ships, mobile plant equipment are few examples where fillet welding are used extensively. Analysis of welded structures are still remains a challenge for the designer to produce desired output results. In welding process rapid heating and cooling introduced residual stress and geometrical deformations. Heat effected zone play pivotal role in determining the strength of a welded joint which changes the properties of parent material and reduce the strength after welding operation. There are many case which structures are continuously under cyclic loading when the fatigue life of the welded joints are a major design consideration. The aim of this project is to analyse the normal stress and fatigue life of fillet welded joints using computer modelling and experiments. Finite element based tool ANSYS Workbench 15.0 was been used to analyse the normal stress and the fatigue life under cyclic loading. Computer model of the joint developed using three different types of material which was parent metal, heat affected zone metal and weld metal. Experimental tests were carried out at USQ laboratory on double side welded T-joints. Grade 250 Structural steel was used to prepare specimen and gas metal arc welding (GMAW) process applied to welding the joints. The ultimate purpose of the project has been achieved with developing techniques of the finite element analysis of fillet welded joint. The experimental investigation validate the performance of the FEA analysis results were found 1.2% error on tensile test. The experiment yield stress was found 263.4 MPa and simulation yield stress at the same location appears 266.7 MPa. In order to calculate fatigue life of welded joint used iterative process to define stress at one million cycle. The analysis found 274 MPa stress and 7740 cycle fatigue life applying yield load. After reduced load at 12kN and found the fatigue life one million cycle where shows 88 MPa stress which is 35% of yield stress. So that designer can consider 35% of yield strength when design structure for fluctuating and repeated loading conditions

Ready Made Garments’ (RMG) Contribution in Women Empowerment: A Study on Bangladesh Perspective

There is no denying the fact that without women empowerment development goals of Bangladesh is always unreachable. This country belongs to a social system where women consider as a burden for the family. However, the scenario is changing with time. Nowadays, women are working in garments sector, education sector, banking sector, different NGO’s and government organizations but the single garment sector where seventy percent of workers of 4.0 million are women and most of them are less educated, unskilled and from rural areas. These women have neither decision making power and nor access to resources before getting the job in the garments sector. The job creates ample opportunity for female workers by giving economic freedom, keeping them near the resources and facilities in the city area, and making them knowledgeable, and skills through training, counseling, and sharing problem with coworkers. The study reveals that empowerment of women vastly depends on four variables which are women’s financial contribution to family, women’s access to resources, women’s participation in household decision making and their perception of coping capacity to shocks. It has been found that garments sector significantly contribute to enhance the female worker’s ability to contribute financially, to participate in decision making, to access resources, and to cope with risks which ultimately increase their empowerment in the society as a whole

Estimation of the Optimal Forest Rotation of Sissoo (Dalbergia sissoo) Plantations in Bangladesh

Using various criteria, the paper estimates the optimal rotation period for Sissoo (Dalbergia sissoo) plantations in Bangladesh. Plantations data were collected during 1999-2000 from purposively selected Forest Divisions aged at least 5 years. Under the present management system, mode of marketing, market mechanism and all economic criteria for Bangladesh as a whole, the optimal rotation of Sissoo tree is estimated to be at 8 years for fuel wood and 12 or 13 years for timber. If the Mean Annual Increment (MAI) is considered as rotation criterion, rotation period as 6 years for fuel wood and 11 to 13 years for timber are suggested. The elimination rates varied from 10% to 72% depending on plantation year, location, biotic interference and sissoo mortality. Irrespective of locations, it was revealed that the highest NPV (Tk 6395599), IRR (85%), B/C ratio (6.57), and  (Tk 2608031) start from the 13 year-old plantation. Keywords: Sissoo, Optimal rotation, Forest management, Bangladesh

Communications cryptography

In today's information age, communications play an important role which 1s contributed to the growth o f technologies. Electronic security is increasingly involved in making communications more prevalent. Therefore, a mechanism is needed to assure the security and privacy o f information that is sent over the electronic communications media is in need. Whether the communications media is wired o r wireless, both can be not protected from unauthorized reception or interception of transmission. The, method of transforming the original information into the unreadable format is called encryption and decryption of information. The study o f encryption and decryption is known as Cryptography. Cryptography or communication by using secret code was used by the Egyptians some 4000 years ago. However, t h e science of cryptography was initiated by Arabs since 600s. Cryptography becomes vital in the twentieth century where it played a crucial role in the World War I and 11. This paper focuses on the analysis of the two types of key cryptography exists, based on the availability of the key publicly: Private key Cryptography, and Public Key Cryptography. Both the sender and the recipient share a key that must be kept private. In the former case the sender and recipient share a private key between the two o f them which must be distributed first before actual communications take place. This analysis shows how much complicated and difficult to do properly. T h e most famous example o f t h i s type of cryptography is the Data Encryption Standard (DES). In the Public Key Cryptography, each party has two sets o f keys; one key is known to the public while the other is kept secret to the owner

Novel packet scheduling algorithm based on cross component carrier in LTE-advanced network with carrier aggregation

LTE-Advanced provides considerably higher data rates than the early releases of LTE. The carrier aggregation CA) technology allows scalable expansion of effective bandwidth provided to user equipment (UE) through simultaneous utilization of radio resources across multiple carriers. In this paper we propose a new packet scheduling (PS) criterion algorithm that charmingly satisfies the fairness among the different kinds of UEs by designing a weighting factor to proportional fair (PF) packet scheduling (PS) algorithms, while enhancing their throughput performance. The proposed PS algorithm is implemented and validated in a PS module for LTE\LTE-Advanced via system level simulations. Results show that PS-modified algorithms achieve higher throughput for both LTE and LTE-Advanced UEs

Energy harvesting network with wireless distributed computing

Bulky processing tasks are expected to burden the limited resources of energy harvesters by draining the stored energy, and thereby, reaching rapidly to energy causality constraint. In such scenario, energy harvesters flip into sleep mode, and thereby, the execution time of the next task will be delayed until the energy harvesters revert back into active mode. To tackle this problem, this paper proposes a novel energy harvesting network (EHN) that deploys wireless distributed computing (WDC) network within the decision making process (DMP). The DMP is formulated as constrained partially observable Markov decision process in order to enable the energy harvesters to act under uncertainty. Furthermore, various challenges of WDC networks, e.g., nominating the collaborating nodes and task allocation, have been addressed herein. Unlike conventional research works on WDC networks, a system model is proposed for WDC network based on divisible load theory instead of graph theory. In addition, an adaptive task allocation algorithm is proposed to distribute the task efficiently among the collaborating nodes. Finally, the novel EHN system is analyzed and compared against the conventional research works on WDC, offloading computing, and local computing-EHN, where the proposed system is found to outperform in terms of energy and delay

Unexplained recurrent hematuria and clot retention following transurethral resection of the prostate

Severe hemorrhage following a prostatectomy is a rare and serious complication. A 60-year-old male with recurrent hematuria and clot retention following transurethral resection of the prostate  (TURP) which led to anemia presented at our department and was treated with repeated clot evacuation and fulguration and lastly re-resection and fulguration succeed to stop bleeding. At 18 months follow-up, the patient had recovered well. We concluded that re-resection and fulguration on fresh tissue without opening the venous sinusoids should be considered as one of the effective treatment of choice in recurrent hemorrhage following TURP.