1,765 research outputs found

    Challenges and Opportunities to Improve Tuberculosis Screening Among Immigrant Plantation Workers in Sabah, Malaysia

    Get PDF
    Tuberculosis (TB) among immigrants has substantial contribution to the TB epidemiology in Sabah. This study aimed to determine the yield of screening for TB disease among immigrant plantation workers in Sabah, Malaysia. This was a prospective cohort study involving 482 legal immigrant workers aged 18 years and above, consented and available at study sites during the study period. Workers with previous history of TB or currently on TB treatment were excluded from participation. Symptom based questionnaire was administered along with both chest radiograph and sputum samples collection for symptomatics participants. Out of 482 plantation workers creened, there was no case of active TB detected among the 44 (9.1%) symptomatics participants. Finding of low TB yield in this study was rather unexpected but this indicates the real challenges for the local health authority to come out with more cost effective screening programs, including reducing stigma, in active TB screening among migrant population

    Linear-nonlinear stiffness responses of carbon fiber-reinforced polymer composite materials and structures: a numerical study

    Get PDF
    The stiffness response or load-deformation/displacement behavior is the most important mechanical behavior that frequently being utilized for validation of the mathematical-physical models representing the mechanical behavior of solid objects in numerical method, compared to actual experimental data. This numerical study aims to investigate the linear-nonlinear stiffness behavior of carbon fiber-reinforced polymer (CFRP) composites at material and structural levels, and its dependency to the sets of individual/group elastic and damage model parameters. In this regard, a validated constitutive damage model, elastic-damage properties as reference data, and simulation process, that account for elastic, yielding, and damage evolution, are considered in the finite element model development process. The linear-nonlinear stiffness responses of four cases are examined, including a unidirectional CFRP composite laminate (material level) under tensile load, and also three multidirectional composite structures under flexural loads. The result indicated a direct dependency of the stiffness response at the material level to the elastic properties. However, the stiffness behavior of the composite structures depends both on the structural configuration, geometry, lay-ups as well as the mechanical properties of the CFRP composite. The value of maximum reaction force and displacement of the composite structures, as well as the nonlinear response of the structures are highly dependent not only to the mechanical properties, but also to the geometry and the configuration of the structures

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

    Get PDF
    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

    Performance evaluation of VLC system using new modulation approach

    Get PDF
    We propose a modified OFDM modulation based on multiband scheme for visible light communications (VLC) system. The method called catenated-OFDM VLC system can efficiently boost the propagation distance and combat multipath induced the inter symbol interference and inter carrier interference. Design parameters such as number of optical bands, input power, distance and data rate are varied to see their effect on the system performances. Simulation analysis is done using Optisys software Ver. 11.0. The results show that the proposed system offers a good performance at longer transmission distance of 12 m for input power of 2 dBm in case of Band=3 with 10 Gbps data rate. BER curves also indicates that the proposed system can be operated at very high data rate of 15 Gbps. This exhibits the ability of the proposed system to be one of the candidate for future optical wireless communication system

    A quasi-brittle damage model in the framework of bond-based peridynamics with adaptive dynamic relaxation method

    Get PDF
    Peridynamics (PD) is a new tool, based on the non-local theory for modelling fracture mechanics, where particles connected through physical interaction used to represent a domain. By using the PD theory, damage or crack in a material domain can be shown in much practical representation. This study compares between Prototype Microelastic Brittle (PMB) damage model and a new Quasi-Brittle (QBR) damage model in the framework of the Bond-based Peridynamics (BBPD) in terms of the damage plot. An in-house code using Matlab was developed for BBPD with inclusion of both damage models, and tested for a quasi-static problem with the implementation of Adaptive Dynamic Relaxation (ADR) method in the theory in order to get a faster steady state solutions. This paper is the first attempt to include ADR method in the framework of BBPD for QBR damage model. This paper analysed a numerical problem with the absence of failure and compared the displacement with literature result that used Finite Element Method (FEM). The obtained numerical results are in good agreement with the result from FEM. The same problem was used with the allowance of the failure to happen for both of the damage models; PMB and QBR, to observe the damage pattern between these two damage models. PMB damage model produced damage value of roughly twice compared to the damage value from QBR damage model. It is found that the QBR damage model with ADR under quasi-static loading significantly improves the prediction of the progressive failure process, and managed to model a more realistic damage model with respect to the PMB damage model

    Effect of particle discretisation and horizon size on the displacement and damage plot using bond-based peridynamics

    Get PDF
    Peridynamics (PD) represents a new non-local theory of continuum mechanics which uses integro differential equations instead of the typical local partial differential equations in its formulation. Thus, it is suitable for modelling fracture mechanics, where a continuum domain is modelled through particles connected via physical interactions. The PD formulation allows us to model spontaneous crack initiation, and crack branching without the need for special mathematical treatment. The value of parameters such as particle discretisation and horizon size will be checked to make sure that it agreed to the result from Finite Element Method (FEM) in elastic deformation before proceed to the failure mode. In PD, failure criterion is established when its stretch value exceeds a prescribed critical stretch value. In the classical bond model or Prototype Microelastic Brittle (PMB), the bond force grows linearly with the bond stretch, and the value suddenly goes down to zero when the bond stretch exceeds its critical value. This study will focus on the effect of horizon size and particle discretisation on PD displacement of elastic analysis, and damage patterns with PMB damage model. The proposed study leads to a better understanding of how horizon size and particle disretisation affect the damage patterns in PD frameworks

    Evaluating potential of diatomite as anti clogging agent for porous asphalt mixture

    Get PDF
    Clogging is a major problem that occurs throughout the service life of porous asphalt due to the open nature of the mixture itself. Diatomite with characteristic of abrasiveness and porous structure seems to have potential in order to remove the clogging materials that mainly consists of soils. This study aims to investigate the effects of diatomite as anti-clogging agent on the permeability rate and strength of porous asphalt. The porous asphalt samples were prepared using Malaysia aggregate gradation and polymer modified bitumen of PG76 was used as the binder. This study focuses on clay as the clogging material at different concentration. A fixed amount of 0.5 g/L diatomite was applied to the porous asphalt samples as an anti-clogging agent prior to clogging cycles. The permeability test and resilient modulus were then conducted at different clogging concentrations (0.5, 1.0, 1.5 g/L) and cycles, with and without diatomite. It was found that samples with diatomite have a higher permeability rate compared to those without any application of diatomite after a few clogging cycles. As the clogging cycles increase, the clogging materials have trapped and filled up the voids in the porous asphalt samples and increase the resilient modulus result

    Autonomous vehicle convoy using Lego Mindstorms

    Get PDF
    ABSTRACT -Autonomous vehicle convoy is a future driving and technology system that have been researched and developed for decades to solve problems in our transportation system nowadays. The increasing of road traffic has contributed to traffic congestion and more severely causes accidents. The aims of this study are to develop convoy algorithm and demonstrate autonomous vehicle convoy system using the LEGO Mindstorms Education EV3 by performing convoy experiment using small scaled car. The convoy or platooning need to satisfy the range of constraints by keeping the control parameters. It consists of one leader and two followers which have to maintain speed and safe distance while moving at designated route

    A Review of User-Centred Design Methods for Designing a Portable Oil Spill Skimmer

    Get PDF
    Boom and skimmer are mechanical techniques in Oil Spill Response and Recovery (OSRR) that collect oil from the water surface. However, there are several drawbacks of using boom and skimmer, such as the oil could pass over the boom during strong wind and high tides. Moreover, the currently available oil skimmer designed by the engineers is heavy-duty; in consequence, it is ineffective in shallow water. Thus, there is a need to develop a portable oil spill skimmer to complement the current drawbacks. Several journals on the fabrication of the oil spill skimmer were reviewed. Findings from literature shows that the development of oil spill skimmer lacks user requirements when designing a portable oil spill skimmer. This article provides a systematic review of Kansei Engineering and the Analytical Hierarchy Process in the product development process. Therefore, Kansei Engineering and Analytical Hierarchy Process (AHP) can be incorporated in the early stage of designing a portable oil spill skimmer. This paper also includes the application of Kansei Engineering and AHP in design research articles. Findings from observed articles indicate a lack of design and development technologies relating to products for environmental protection; the AHP and Kansei Engineering application is somewhat lacking. Moreover, the fabrication of an oil spill skimmer focuses more on technical specifications and includes fewer user requirements. As a result, the characteristics such as ease of use, robustness, and safety cannot be evaluated. The AHP and Kansei Engineering methodology can be extended to the design and manufacture of products for environmental protection
    corecore