Failure Analysis on Skunk-Arm of Electrical Tower

Un-proper procedure during installation of the wire-rope could introduce unusual loading to the skunk-arm of the high-voltage electrical tower. Understanding of structural behavior of this kind of structure under different loading should be helpful to take preventive measure again possible future accidental cases. Static and buckling analyses have been performed using Finite Elements Analysis (FEA). Skunk-arm structure modelized by one-dimensional elements, combination between bar and beam. Beam elements represent main structure that are flexural members and bar elements represent stiffener that can only be in tension or compression loading. Stress distribution due to maximum static loading did not show an excessive stress value, it means no yielding occurs in the structure. But buckling factor show the maximum loading is close to the critical loading that may provoke collapse of structure in buckling mode. The result shows the mechanism of structure failure, which begin with buckling of the lower members of the skunk. In normal condition, factor of safety of 2 is taken according to maximum loading of the structure

Crushing Modes of Aluminium Tubes under Axial Compression using Finite Element Analysis

Nowadays, aluminium tubes have been used widely as a controlled absorption of kinetic crash energy. The energy absorption process is subjected to axial loading is based on the formation of plastic folds. A numerical study of the crushing of aluminium circular tubes has been carried out to investigate their buckling behaviors under axial compression and to predict the energy absorbed by the tube. Circular tube with diameter 25.4 mm, height 25.4 mm and thickness 0.29 mm is compressed axially with velocity 5 mm/min using ABAQUS/CAE 2016 between two rigid platen. Typical deformation mode is studied and presented. Mixed mode has been deformed because of the ratio of the wall thickness, diameter and the length of the tubes. These approved that geometry of the tube influence the deformation mode as well as the energy absorbs by the tube

Fire Fighting Mobile Robot: State of the Art and Recent Development

The fire fighting is a risky work where the fire fighters need to face the fire hazards to save life and properties. Different equipment such as fire extinguisher, axes and cutting equipment are used to fight against fire. Fire fighting vehicle is being used to transport firefighters to the scene as well as transport the fire fighting equipment. The fire fighter is still facing the risk of fire hazard because they still need to go near to fire scene. To reduce the fire fighter risk during fire incident, a fire fighting mobile robot is designed. Fire fighting mobile robot is a remote controlled machine that replace fire fighter to perform fire fighting task. The application of fire fighting mobile robot is able to reduce the direct contact of fire fighter to the fire hazards. The paper reviews a variety of technologies and state-of-the-art technology of fire fighting mobile robot. The paper also describes the first Malaysian designed and built fire fighting mobile robot, namely, MyBOT2000

Design of Urea Granulator for Environmental Friendly Urea

Urea granules are one of the popular fertilizers among synthetic fertilizer industry. Its main function is to provide nitrogen which enhances leaf growth on plant. Urea granules are produced from the process of granulation. Granulation process is divided to wet and dry granulation. Generally, there are two type of dry granulator which is slugger and roller compactor. Roller compactor or also known as roll press is using two counter rotating rolls to compact raw material such as powder to become ribbons or granules. If ribbons instead of granules are produced from compaction, milling will be used to produce granules. It is difficult obtain a numerical result of the process due to the variety of parameters. Therefore, this work will only consider the parameters which are related to feeder system and roller. The parameters include the feeding rate of feeder, roller force, roller pressure, and roller gap size. While powder flow to roller from feeder, overfeeding may occurs. Overfeeding is harmful because it will cause motor failure. To overcome this problem, the function of roller needs to be improved. The roller will be modified and hence, a new design will be produced

Critical exponents and equation of state of the three-dimensional Heisenberg universality class

We improve the theoretical estimates of the critical exponents for the three-dimensional Heisenberg universality class. We find gamma=1.3960(9), nu=0.7112(5), eta=0.0375(5), alpha=-0.1336(15), beta=0.3689(3), and delta=4.783(3). We consider an improved lattice phi^4 Hamiltonian with suppressed leading scaling corrections. Our results are obtained by combining Monte Carlo simulations based on finite-size scaling methods and high-temperature expansions. The critical exponents are computed from high-temperature expansions specialized to the phi^4 improved model. By the same technique we determine the coefficients of the small-magnetization expansion of the equation of state. This expansion is extended analytically by means of approximate parametric representations, obtaining the equation of state in the whole critical region. We also determine a number of universal amplitude ratios.Comment: 40 pages, final version. In publication in Phys. Rev.

Comparison of Xpert GBS v. culture for rapid detection of group B streptococcus in pregnant women: Sensitivity, specificity and predictive values

Background. Group B streptococcus (GBS) is a leading cause of invasive disease, particularly in newborns. Seventy-five percent of neonates will be colonised by mothers carrying the organism. Confirmation of maternal colonisation with GBS is essential for prompt treatment and prevention of neonatal sepsis. The current gold standard of culture for isolation of GBS has a disadvantage of long turnaround time (24 - 72 hours). Rapid assays are required to determine maternal carriage of GBS.Objectives. To determine the usefulness of the Xpert GBS technology v. culture methods to detect GBS carriage in pregnant women.Methods. This was a prospective observational study of 284 pregnant women between 26 and 37 weeks’ gestation. Two vaginorectal swabs were collected from each participant. One swab was processed using the gold-standard culture method, while the second swab was processed using the Xpert GBS assay. The performance of the Xpert GBS assay was then compared with that of the culture method.Results. Two swabs were processed from each of 284 pregnant women between 26 and 37 weeks’ gestation. Culture detected 70 GBS isolates from a total of 279 specimens (25.1%), whereas the Xpert GBS detected 66 positive specimens (23.7%). The Xpert GBS assay had a sensitivity of 87% and specificity of 98%, with a positive predictive value of 92% and a negative predictive value of 96%.Conclusions. The Xpert GBS assay is a rapid and sensitive tool for prenatal detection of GBS. The assay should ideally be available in every labour ward, where women can be screened for GBS on arrival

Empty Aluminium Honeycomb under Quasi-Static Loading: Experiment and Simulation

In recent years, study involving aluminium honeycomb has grown rapidly. This is due to the properties of aluminium honeycomb that are very useful in energy absorbing area. This paper focuses on compressing the aluminium honeycomb in all directions; in-plane and out-of-plane direction for both experimental and simulation work. It is found that compression in out-of-plane direction offered far superior energy absorbing characteristic compared to the in-plane directions. Factor that contributes to this difference is found to be the imperfection of the aluminium honeycomb itself. All honeycomb deformed dissimilarly base on the stiffness and direction of compression

Ground Vehicle for Fire Fighting Purpose in Hazardous Environment

In this project, design, development and performance of a wirelessly controlled Fire Fighting Ground Vehicle (FIGOV) is described. FIGOV is a wireless control mobile machine that is equipped with firefighting equipment. It carries high density camera, sensors, communication equipment, firefighting equipment and other loads in order to control fire and perform victim searching task. The machine is wirelessly controlled via mobile computer. The nozzle of the machine can be directed at different angle and can be elevated in order to control fire at different height. FIGOV can be used to reduce the risks faced by fire fighters in performing their duties. This is due to the fact to the current fire fighting techniques require fire fighters to intervene in hazardous conditions. Working at very high temperature, dusty, low humidity, dangerous and others are among usual working conditions associated with fire fighting. Study conducted showed that the machine can be successfully be used in real fire fighting process. Effective use of the machine also can avoid direct contact of human especially fire fighter with radioactive or hazardous materials that may have immediate or long-term effects on health as well as fatigue to human

Conceptual design of cantilever support for long haul bus passenger seat

This paper describes the conceptual design of cantilever support for long haul bus passenger seat. The advantages of cantilever bus seat structure is light weight, the luggage can be put under the seat and it is easy for floor cleanup. The total design technique was used to develop the cantilever support. Market survey was conducted to study on current available cantilever supported vehicle seat. After that, product requirement of cantilever design is defined. Next, brainstorming technique was used to generate the preliminary concept of cantilever design. Six conceptual designs were generated for selection. The matrix evaluation method was used to determine the final design of cantilever design. The weight of the concept was obtained through weighted analysis. Lastly, the final concept will be fabricated as prototype for further validation purpose

Comparison of Xpert GBS v. culture for rapid detection of group B streptococcus in pregnant women : sensitivity, specificity and predictive values

BACKGROUND. Group B streptococcus (GBS) is a leading cause of invasive disease, particularly in newborns. Seventy-five percent of neonates will be colonised by mothers carrying the organism. Confirmation of maternal colonisation with GBS is essential for prompt treatment and prevention of neonatal sepsis. The current gold standard of culture for isolation of GBS has a disadvantage of long turnaround time (24 - 72 hours). Rapid assays are required to determine maternal carriage of GBS. OBJECTIVES. To determine the usefulness of the Xpert GBS technology v. culture methods to detect GBS carriage in pregnant women. METHODS. This was a prospective observational study of 284 pregnant women between 26 and 37 weeks’ gestation. Two vaginorectal swabs were collected from each participant. One swab was processed using the gold-standard culture method, while the second swab was processed using the Xpert GBS assay. The performance of the Xpert GBS assay was then compared with that of the culture method. RESULTS. Two swabs were processed from each of 284 pregnant women between 26 and 37 weeks’ gestation. Culture detected 70 GBS isolates from a total of 279 specimens (25.1%), whereas the Xpert GBS detected 66 positive specimens (23.7%). The Xpert GBS assay had a sensitivity of 87% and specificity of 98%, with a positive predictive value of 92% and a negative predictive value of 96%. CONCLUSIONS. The Xpert GBS assay is a rapid and sensitive tool for prenatal detection of GBS. The assay should ideally be available in every labour ward, where women can be screened for GBS on arrival.The research described in this article was an MMed project of MS, the main author.A National Health Laboratory Services Research Grant (no. 94443) in fulfilment of MS’s MMed project.http://www.samj.org.zaam2019Medical MicrobiologyObstetrics and Gynaecolog