265 research outputs found

    Crosstalk improvement of polymer in glass thermo-optical multimode interference switch

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    A new structural design of combined variable optical attenuator (VOA) and optical switch has been proposed in this paper. The design is based on the multimode interference (MMI) architecture and it has been demonstrated for crosstalk improvement of optical switch. The device operates by manipulating thermo-optic (TO) effect that naturally existed in all optical waveguide material. By applying a polymer on glass material platform, the optimized VOA with optical attenuation of 21.52 dB has been achieved with applied power of 36.4 mW. The simulation result shows that the VOA helps to achieve significant improvements of optical switch performance particularly in crosstalk reduction up to 89.66%

    User friendly system for the visually impaired in learning Al-Quran

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    This study presents a method to enable the visually impaired Muslim to learn and read the Al-Quran using Braille Display with software help. The system reads the database which contains all verses of Al-Quran and user will need to select the verse and ayah to read. Besides that, this system can be used in a class to teach visually impaired students to learn Al-Quran. Every word or character typed by the instructor in the main Braille Panel will be transmitted to the sub Braille Panel that is connected to the main Braille Panel. The selected verse of Al-Quran and ayah will also generate an index before being transmitted to the Braille Panel. The index will be transmitted to the Braille Display for people to touch and read the display. A user friendly Graphical User Interface (GUI) will be used to fulfill the ergonomics for the visually impaired user's physical capabilities. Several approaches are used to design and implement the interface for the visually impaired like speech or sound output and Braille display. The Braille codes can be displayed using the Braille panel. The design interface and structure of the system for the visually impaired users in learning Al-Quran is presented

    A Review on Honey Adulteration and the Available Detection Approaches

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    Over the last few decades, the utilization of stingless bees honey product grew significantly due to its natural therapeutic value in honey. These make the demand for honey rises and tends to have a lot of honey product available in the commercial market. However, the purity of honey can be sceptical whenever it turns up to be added or removed with different substances. Recently, adulteration of honey becomes a complex issue because the highly sophisticated adulteration procedures are continually being evolved and the legislative determination of honey quality indicator is incapable to identify most honey adulteration procedures. Therefore, a comprehensive overview of the method of adulterated honey, including direct and indirect adulteration are discussed in this paper. In addition to this, the detection methods approached by most researchers are briefly explained. All these methods contribute to the knowledge about each aspect of honey authenticity and give beneficial information in oncoming works

    Carbonization cbn550 effect on tensile properties of composite for marine structure application

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    The composites have gained commercial success, where strength, stiffness, durability and light weight are required as well as retardant capacity. Improvement has been made such new series of resin such as vinyl ester and epoxy type[1, 2]. However 95% of pleasure vessels and boats under 60 feet today are still made with polyester resin. The main consideration for most composite builders is cost, with performance and more importantly value for money often being a secondary consideration. Therefore, this study investigate the tensile - mechanical effects of mixing carbon black CBN550 with wax and non-wax type resin and manufactured according to fiber orientation of [0°] and [90°]. The 10% CBN550 exhibit highest reading for stress under [90°] fiber orientation and the lowest reading when arranged at [0°] fiber orientation. The preliminary study on CBN550 flammability has indicated the suitability for this study to pursue in. The structural composites samples of 1000 mm by 1000 mm prepared which consist of 10 of composite mats layer in combination of CSM 450 g/m2 and Woven Roving 600 g/m2. The carbon black (CB) volume fraction range from/with 0% to 20% volume fractions. Optical observation revealed the most suitable fraction of CBN550 in wax polyester resin is at 10% and non-wax polyester resin is also at 10%. The fire resistance behaviour of this CBN550 - CSM 450 g/m2 - Woven Roving 600 g/m2 composite (polyester wax) and polyester non wax was investigated previously as per[3]. This results are in line with the finding of the maximum load where the highest reading was recorded by the 10%CBN550 specimen. This study showed that the introduction of carbon black into the resin mixture helps reinforce the matrix materials. The results suggested that CBN550 mixture should attend to next level of experiment investigation such as oxygen content, TG value, microstructure and other mechanical destructive test. The CBN550 could be a suitable candidate for fire retardance application in marine composite structure

    Comparative mechanical properties study of resin infusion versus hand laminating for the construction of 12-ft fishing boat

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    Resin Infusion is widely used to produce fiber-reinforced materials. In the process, the resin enters a close mold containing the dry fiber performed by pressure difference. This study is about finding the comparison of the tensile strength, compression strength and flexural strength between resin infusion technique and conventional hand laminating for the construction of a 12-feet fishing boat. Both boat were applied with the same composite matrices. All testing was done in accordance to the standard ASTM D3039, D3039M, ASTM D695-02a and ASTM D790-07. The result showed that the resin infusion technique produced better result upon ultimate tensile strength (27% better) but slightly less satisfactory for in compressive stress (12% lower) and flexural stress (34% lower). Even though resin infusion was only better in tensile strength, physically the product is more lightweight with a better resin-to-fiber ratio

    The effect of N550 carbon black in polyester resin for fire-retardant application in marine composite

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    This paper presents the experimental investigation on the influence of N550 carbon black (CBN550) series in polyester resin (wax and non -wax type). The CBN550 was added into polyester resin at different weight percentages with a curing agent. The investigation is mainlyto study the effect on fire retardance application in marine composite structure. The fire-resistant structural composites samples of 1000 mm by 1000 mm prepared which consist of 10 of composite mats layer in combination of CSM 450 g/m2 and Woven Roving 600 g/m2. The carbon black (CB) volume fraction range from/with 0% to 20% volume fractions. Optical observation revealed the most suitable fraction of CBN550 in wax polyester resin is at 10% and non-wax polyester resin is also at 10%. The fire resistance behavior of this CBN550 - CSM 450 g/m2 - Woven Roving 600 g/m2 composite (polyester wax) and polyester non wax was investigated by Fire Test Procedure Code-Resolution A.653 [1]. Though smaller filler size escalates the rheological behavior and values outstandingly at initial reading compare to large particles but it slow down the curing processdue to its small particle size, large surface area and high dispersion rate. Experimental data showed the retardance level has been increased up to 56.66% in non-wax type polyester resin (10%/CBN550) and 30.14% in wax polyester resin (10%/CBN550). The improvement in fire resistance points are due to the presence of CBN550 which acts as a positive additive in both polyester resin wax and non-wax. Filling CBN550 in polyester resin also reduces the cost of theend products.The preliminary results suggested that CBN550should attend to next level of experiment investigation such as oxygen content, TG value, microstructure as well as mechanical destructive test. The CBN550 could be a suitable candidate for fire retardance application in marine composite structure.In conclusion, crystallinity of polyester resin increases with additional of CB particles

    Commuting Accidents among Health Care Workers Working in Malaysia Government Hospitals

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    Commuting accidents are accidents occurring while travelling to and from work, and in the course of work. Studies have demonstrated that long working hours are associated with deprived sleeping time. Acute sleep deprivation may result in significant changes in cognitive functioning, alteration of mental status resembling depression or anxiety and difficulty with short-term memory. Some other studies have found that sleep deprivation significantly affects physician performance, alertness and patient safety. However, individual factors concerning workers’ behavior, family-related factors (parenting responsibility), work burden, workplace support as well as environmental factors such as bad weather and bad road conditions are also significant contributors of commuting accidents. The aim of this study is to investigate the relationship of long working hours or odd working hours and the risk exposure of the drivers during their work-commuting trips. The study was based on data collected from official notification forms. Sample size for this research was 554 based on 2014 to 2017 reported cases. Review of the statistics showed that most of the commuting accident causalitiesoccurred during travel to work (30.1%), compared to back from work after normal office hours (28.7%) and during odd hours (night shift and post-call) (12.5%). Nurses contributed significantly to these causalities (53%), followed by hospital attendants (17%), medical officer and assistant medical officer, respectively, 6 percent. Theincreasing number of commuting accidents among healthcare workers is alarming. As such, it is timely that proactive actions be taken by employers to educate their employees, their most valuable assets, on safe commuting management. Keywords: commuting accident, healthcare workers, road crashe

    Prevalence of Sickness Absence and Its Sociodemographic and Occupational Factors in a Public Service Organization

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    Sickness absence in any particular organization has negative impacts mainly toward economic, morale and productivity. The purpose of this survey is to determine the prevalence of sickness absence among employees in a government office in a central region of Malaysia to get profiling of the employees taking medical leaves, tocompare the frequency of sickness absence among the employees based on gender, age group and designation and to determine the perception of sickness absence among the employees in relation to their occupation. A cross-sectional study was carried out among 587 workers in the first half of 2017. Data was collected based on Sickness Absence Surveillance form, which was filled by any employee who took medical leave. Other variables such as demographic data, work characteristics and personal health were also included. Subsequently, data entry and analysis were done using SPSS Version 22.0. The overall prevalence rate was 63.0 percent (female = 42.6%, male 20.3%) that includes repeated medical certificate (MC)-taker. Reasons for sickness absence are varied like fever, URTI, pregnancy related, injury, diarrhea, clinic follow-up and many more. Results also showed that sickness absenteeism was higher among female, mainly middle managerial level, presently or previously married, aged from 30 to 39, employed in the organization for over 10 years with no background of chronic medical illness. Therefore, the prevalence of sickness absence among employees in a government office in a central region of Malaysia and factors associated with it are determined. It is recommended for continuation of surveillance simultaneously to have an intervention program in order to find the root cause of sickness absence and thus reducing sickness absence rate. Keywords: sickness absenteeism, surveillance, sociodemographic factors, occupational factor

    Structural model updating of bolted joints in dissimilar material structure

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    This paper focusing on the joint modelling techniques of Finite Element (FE) to model a light dissimilar structure with bolted joints made up of bolts and nuts. The usage of a model update strategy is employed to improve the FE model's dynamic behaviour. In the FE model, a joint strategy is constructed using three different types of element connectors: CBAR, CBEAM, and CFAST. The modal parameters of a bolted joint structure made of dissimilar materials AZ31B and AA6061 were determined using Finite Element Analysis (FEA) and Experimental Modal Analysis (EMA) in this research (natural frequencies, damping ratio, and mode shapes). The number of elements, number of nodes, and total percentage errors of respectively initial FE model, when compared to EMA results, were evaluated. In comparison to the others, the CBAR element was chosen to represent a fastener joint for the updating process due to its accurate prediction of mode shapes and inclusion of updating parameters. Sensitivity analysis is performed before the updating process to choose the most sensitive parameter for updating purposes. In the FE model updating procedure, MSC Nastran's optimization technique is applied. Therefore, the discrepancies between FEA and EMA have been decreased. When compared to the measured equivalent, the percentage of error for the modified CBAR model drops from 4.37 percent to 2.71 percent. As a result, it is discovered that updating the FE model is a systemic and efficient technique in conducting the appropriate FE model in recreating the genuine structure

    Befogged

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    Porous Asphalt (PA) is known as a highly permeable asphalt surface that design to be permeable pavements for stormwater control and reduce the stormwater runoff. However, the structure is subjected to damage from cracking, rutting, stripping, and rapid aging under the effects of repeated vehicle loading, hot climates, and heavy rainfall. To overcome this, PA needs to modify using high tensile strength like steel fiber. Thus, this study aims to evaluate the performance of PA with the addition of steel fiber and overcome the issue that is related to PA. A mixture contains varying percentages of steel fiber were assessed to check which samples gives the best performance as per the requirement by using laboratory tests which are LA Abrasion, Resilient Modulus, Marshall Stability, and Density. The results show that the additions of 0.6% steel fiber give the lowest value of abrasion, while 0.5% fiber content contributes the highest value of Resilient Modulus and Marshall Stability respectively. PA mixtures modified with steel fiber produce the performance enhancement of PA as a road surfacing material. It is concluded that the asphalt mixtures containing steel fibers could increase the stability and strength of the mix
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