284 research outputs found

    Awareness and knowledge on modern biotechnology

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    Biotechnology has been considered as a very important industry in helping Malaysia to achieve its goal of becoming a highly industrialized nation by 2020. Thus, assessment of people’s knowledge and awareness on biotechnology is very important and according to a theory on decision making, people only form attitudes about technologies when they have acquired relevant information. The purpose of this paper is to study the awareness and knowledge level of the Malaysia public in the Klang Valley region and to compare their awareness and knowledge level across stakeholder groups. A survey was carried out in the Klang Valley region from August 2009 till February 2010 using self constructed  multidimensional instrument measuring ethical perception of transgenic banana. The respondents (n = 434) were stratified according to stakeholder groups which consisted of eleven groups: Producers, scientists, policy makers, NGOs, media, religious scholars, university students and consumers. Results of the survey showed that overall mean score for awareness and knowledge on modern biotechnology were moderate. ANOVAs showed significant differences in awareness on modern biotechnology across several background variables such as stakeholders’ group and educational level. Knowledge level differed significantly across stakeholder groups, educational level, religion, races, age groups and gender. The research findings serve as a useful database for understanding the level of awareness among the public in developing country.Key words: Awareness, knowledge, engagement, modern biotechnology, Malaysia

    Genetic algorithm optimization and control system design of flexible structures

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    This paper presents an investigation into the deployment of genetic algorithm (GA)-based controller design and optimization for vibration suppression in flexible structures. The potential of GA is explored in three case studies. In the first case study, the potential of GA is demonstrated in the development and optimization of a hybrid learning control scheme for vibration control of flexible manipulators. In the second case study, an active control mechanism for vibration suppression of flexible beam structures using GA optimization technique is proposed. The third case study presents the development of an effective adaptive command shaping control scheme for vibration control of a twin rotor system, where GA is employed to optimize the amplitudes and time locations of the impulses in the proposed control algorithm. The effectiveness of the proposed control schemes is verified in both an experimental and a simulation environment, and their performances are assessed in both the time and frequency domains

    Prevalence of somatisation and psychologisation among patients visiting primary health care centres in the State of Qatar

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    Background: Medically unexplained somatic complaints are among the most common clinical presentations in primary care in developing countries and they are considerable burden for patients and health care system. Objectives: The aim of this study was to determine the prevalence of somatisation in comparison to psychologisation among a sample of Qatari patients who were visiting primary health care (PHC) centres and to investigate the clinical and socio-demographic characteristics of somatisers (STs) and psychologisers (PGs). Method: The survey was conducted among PHC Qatari patients during the period from January to July 2007. About 2,320 patients were approached, of whom 1,689 agreed to participate and responded to the questionnaire. Among the studied Qatari patients, 404 patients were identified for clinical interview. The first stage of the study was conducted with the help of general practitioners, using the 12-item General Health Questionnaire. The second stage was carried out by a consultant using the Clinical Interview Schedule. A specific operational criterion was used to identify STs and PGs. Results: The prevalence rate of STs among the total studied sample was 12.4%, while the PGs were 11.5%. Among the identified psychiatric cases, the proportion of STs (52%) was higher than PGs (48%). Most of the diagnostic categories were more prevalent among PGs. The dissatisfaction at work and stressful life events within 12 months before the onset of the presenting symptoms were the three postulated determinants which were significantly more among STs than PGs. Conclusion: The prevalence of somatised mental disorder was little higher than the psychologised mental disorder. The prevalence of somatisation and psychologisation is comparable with other reported studies from the Middle-East and Western countries. Dissatisfaction at work and stressful life events were significantly higher among STs than PGs.Keywords: somatisers; psychologisers; primary health care; determinants; Arab cultur

    Properties of a Low-Carbon Binder-Based Mortar Made with Waste LCD Glass and Waste Rope (Nylon) Fibers

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    Carbon dioxide emissions are one of the problems that arouses the interest of scientists because of their harmful effects on the environment and climate. The construction sector, particularly the cement industry, is a significant source of CO2. On the other hand, solid waste constitutes a major problem facing governments due to the difficulty of decomposing it and the fact that it requires large areas for landfill. Among these wastes are LCD waste glass (WG) and used rope waste. Therefore, reusing these wastes, for example, in concrete technology, is a promising solution to reduce their environmental impact. Limited studies have dealt with the simultaneous utilization of glass waste as a substitute for cement and rope waste (nylon) fiber (WRF). Therefore, this study aimed to partially replace cement with WG with the addition of rope waste as fibers. Thirteen mixtures were poured: a reference mixture (without replacement or addition) and three other groups containing WG and WRF in proportions of 5, 15 and 25% by cement weight and 0.25, 0.5 and 0.75% by mortar weight, respectively. Flow rate, compression strength, flexural strength, dry density, water absorption, dynamic modulus of elasticity, ultrasonic pulse velocity and electrical resistivity were tested. The results indicate that the best ratio for replacing cement with WG without fibers was 5% of the weight of cement. However, using WRF increased the amount of glass replacement to 25%, with an improvement in strength and durability characteristics

    Potential Use of Rendering Mortar Waste Powder as a Cement Replacement Material: Fresh, Mechanical, Durability and Microstructural Properties

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    The difficulty of decomposing solid waste over time has made it a significant global problem because of its environmental impact and the need for large areas for disposal. Among these residues is the waste of the rendering mortar that is produced (falls to the ground) while applied to wall surfaces. The quantity of these materials may reach 200 to 500 g/m2. As a result of local urban development (in Iraq), thousands of tons of these wastes are produced annually. On the other hand, the emission of greenhouse gases in the cement industry has had a great environmental impact. One of the solutions to this problem is to reduce the cement content in the mix by replacing it with less emissive materials. Residues from other industries are considered a relatively ideal option due to their disposal on the one hand and the reduction of harmful emissions of the cement industry on the other hand. Therefore, this research aims to reuse rendering mortar waste powder (RMWP) as a possible alternative to cement in mortar. RMWP replaced the cement in proportions (0, 10, 15, 20, 25, and 30% by weight). The flow rate, flexural and compressive strengths, ultrasonic pulse velocity, bulk density, dynamic modulus of elasticity, electrical resistivity, and water absorption tests of the produced mortar were executed. Microstructural analysis of the produced mortar was also investigated. Results indicated that, for sustainable development, an eco-friendly mortar can be made by replacing cement with RMWP at a rate of 15%, resulting in a 17% decrease in compressive strength while maintaining or improving durability properties. Moreover, the microstructure became denser and more homogeneous in the presence of RMWP

    Performance of Green Mortar Made From Locally Available Waste Tiles and Silica Fume

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    The continuous depletion of natural resources used in concrete require vital replacement materials to reduce the consumptions of the natural resources. Moreover, the growth in the population increases the construction of new houses to accommodate the population, which increases the demand concrete and other construction materials. The replacement of the existing building materials with the newly materials proceed from recycling the waste materials for example, flooring tiles, which is usually disposed of in landfills without any benefit in Iraq. Therefore, this study aims to recycle locally available floor tiles waste by using it as a total alternative to fine aggregate to enhance the sustainability by reducing the depletion of natural aggregates. Three types of waste tiles were used in this research, which are marble, granite, and porcelain. Four mortar mixtures were designed, casted and tested in the research. One control mixture made from natural sand aggregate and three mixtures in which the sand was fully replaced with each of marble, granite, and porcelain waste tiles with comparable grading as that for sand. The cement was partially replaced with a 10% silica fume (SF) in all mixtures. The flowability, mechanical and durability tests of mortar mixtures were investigated. The results indicated that the combination of porcelain waste tiles aggregates with 10% silica fume imparted superior performance compared to all other mixtures with improvements of 99% in the compressive strength, 53% in the flexural strength and 17% in the water absorption resistance

    Performance Comparison of 45° and 90° Herringboned Permeable Interlocking Concrete Pavement

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    Pavement deterioration is mainly caused by high traffic loading and by increased levels of runoff water resulting from storms, floods, or other reasons. Consequently, this issue can be efficiently solved by employing permeable pavement, such as permeable interlocking concrete pavement (PICP) to control water runoff and endure increased traffic loads. This study investigates the performance of PICP, in both 45° and 90° herringboned surface patterns, in terms of the infiltration of volumes of water, runoff water volumes, and the ability of pavement to withstand static loading. All the related tests in this study were implemented using a lab apparatus that was fabricated as a simulator for rainfall. Various conditions were adopted during the performance tests, including the application of longitudinal slopes (0, 2.5, 5, and 7.5%), side slopes (0, 2.5, and 5%), and different rainfall intensities (25, 50, 75, and 100 L/min). The results indicated that at high rainfall intensities (75 and 100 L/min), PICP with the 45° herringboned surface pattern had the highest volume of infiltrated water and the lowest runoff water at all the adopted longitudinal and side slopes. In addition, PICP with the 45° herringboned surface pattern showed higher resistance to deflection under a static loading test than the 90° herringboned pattern under the same conditions. Therefore, PICP with a 45° herringboned surface pattern showed supremacy in terms of runoff reduction and load resistance in comparison to PICP with a 90° herringboned pattern. Even though there are differences between the two types of PICP, they are both strongly recommended as alternatives to regular pavement

    Landsat-8, advanced spaceborne thermal emission and reflection radiometer, and WorldView-3 multispectral satellite imagery for prospecting copper-gold mineralization in the northeastern Inglefield Mobile Belt (IMB), northwest Greenland

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    © 2019 by the authors. Several regions in the High Arctic still lingered poorly explored for a variety of mineralization types because of harsh climate environments and remoteness. Inglefield Land is an ice-free region in northwest Greenland that contains copper-gold mineralization associated with hydrothermal alteration mineral assemblages. In this study, Landsat-8, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and WorldView-3 multispectral remote sensing data were used for hydrothermal alteration mapping and mineral prospecting in the Inglefield Land at regional, local, and district scales. Directed principal components analysis (DPCA) technique was applied to map iron oxide/hydroxide, Al/Fe-OH, Mg-Fe-OH minerals, silicification (Si-OH), and SiO2 mineral groups using specialized band ratios of the multispectral datasets. For extracting reference spectra directly from the Landsat-8, ASTER, and WorldView-3 (WV-3) images to generate fraction images of end-member minerals, the automated spectral hourglass (ASH) approach was implemented. Linear spectral unmixing (LSU) algorithm was thereafter used to produce a mineral map of fractional images. Furthermore, adaptive coherence estimator (ACE) algorithm was applied to visible and near-infrared and shortwave infrared (VINR + SWIR) bands of ASTER using laboratory reflectance spectra extracted from the USGS spectral library for verifying the presence of mineral spectral signatures. Results indicate that the boundaries between the Franklinian sedimentary successions and the Etah metamorphic and meta-igneous complex, the orthogneiss in the northeastern part of the Cu-Au mineralization belt adjacent to Dallas Bugt, and the southern part of the Cu-Au mineralization belt nearby Marshall Bugt show high content of iron oxides/hydroxides and Si-OH/SiO2 mineral groups, which warrant high potential for Cu-Au prospecting. A high spatial distribution of hematite/jarosite, chalcedony/opal, and chlorite/epidote/biotite were identified with the documented Cu-Au occurrences in central and southwestern sectors of the Cu-Au mineralization belt. The calculation of confusion matrix and Kappa Coefficient proved appropriate overall accuracy and good rate of agreement for alteration mineral mapping. This investigation accomplished the application of multispectral/multi-sensor satellite imagery as a valuable and economical tool for reconnaissance stages of systematic mineral exploration projects in remote and inaccessible metallogenic provinces around the world, particularly in the High Arctic regions

    The impact of grinding time on properties of cement mortar incorporated high volume waste paper sludge ash

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    Cement is considered a base material in preparing blending mixtures that applying in various projects in the civil engineering field. Nevertheless, the cement production process cause indubitable negative environmental influences such as emitting CO2. The production of cement produces around 7% of the global CO2 emissions. Thus, searching for alternate binders in building processes to minimise or substitute cement has been one of the social problems. A by-product or waste products are among the potential alternatives to the mentioned problem. The present investigation involves the consumption of paper sludge ash (PSA) waste as cement replacement to produce environmentally friendly, cementitious material. Limited studies were addressed the PSA grinding time impact on mortar or concrete properties. Moreover, limited studies replaced the cement with high volume of PSA. Therefore, during this study, the effect of grinding time and replacement level (up to 50%) of the PSA on the surface electrical resistivity and compressive strength of mortar were investigated. Three grinding periods (in addition to without grinding), two replacement levels and three testing ages were considered. The results indicated that grinding the PSA for 10 minutes and use it to replace up to 50% of the cement content have similar mechanical and durability performance to ordinary Portland cement after 28 curing days. This innovative binder will also cause a major difference in decreasing the building materials cost and CO2 emissions

    The effect of industrial and waste fibres on concrete strength and structural behaviour of rc short columns

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    Concrete is a brittle substance; thus, it is reinforced with rebars and fibers to enhance its ductility. On the other hand, the presence of waste from various industries negatively impacts the environment. The ongoing reconstruction in Iraq has resulted in an abundance of locally produced rebar-connecting wire (RCW) and copper electric wire (CEW) waste. To minimize the environmental impact of these wastes, they can be reused in other industries, such as the concrete industry. Few studies have dealt with concrete's structural and mechanical properties containing these local residues. Therefore, this study included an experimental investigation of concrete columns with and without various types of industrial and waste fibers. Two types of industrial fibers (macro hooked-end; CH, and micro straight; CS) steel fibers and two types of waste fibers (RCW and CEW) were utilized. Six reinforced concrete (RC) columns (150 × 150 × 450 mm3) were cast: one control column without fibers and five columns with fibers. The fiber content within the columns was fixed at 0.75% of the concrete volume. The cracks pattern, load-deflection behavior and concrete strain for RC columns were investigated. Moreover, the mechanical properties in terms of compressive, splitting tensile, and flexural strengths tests were also conducted. The results revealed that all types of fibers used improved the mechanical and structural properties of the concrete. Moreover, although the hybrid synthetic fibers gave the best improvement compared to the reference sample, the waste fibers (especially RCW) showed a significant improvement that reached 30.91% in relation to the ultimate load and (10.1, 10.8 and 14.4%) in relation to the compressive, tensile, and flexural strengths respectively. Konkrit adalah material rapuh; oleh itu ianya dikuatkan dengan besi dan fiber bagi menguatkan kekuatannya. Dalam masa sama, kehadiran bahan buangan dalam pelbagai industri memberi kesan negatif kepada persekitaran. Penstrukturan semula Iraq yang sedang berlangsung memberi kesan kepada kebanjiran bahan buangan seperti besi penghubung litar (RCW) dan litar elektrik tembaga (CEW) buatan tempatan. Bagi mengurangkan kesan pencemaran terhadap alam sekitar, bahan-bahan ini boleh diguna balik dalam industri berbeza, seperti industri konkrit. Terdapat banyak kajian terhadap buangan tempatan yang melibatkan struktur bahan konkrit dan sifat mekanikal.  Oleh itu, kajian ini merupakan kajian eksperimen pasak konkrit dengan atau tanpa pelbagai jenis industri dan fiber buangan. Dua jenis fiber industri iaitu fiber besi (mikro hujung-penyangkut; CH dan mikro lurus; CS) dan dua jenis fiber buangan (RCW dan CEW) dipakai. Enam RC pasak konkrit (150 × 150 × 450 mm3) dihasilkan: satu pasak kawalan tanpa fiber dan lima pasak dengan fiber. Kandungan fiber dalam pasak di tetapkan pada 0.75% isipadu konkrit. Corak rekahan, ciri-ciri kesan beban dan tekanan konkrit pada pasak RC dikaji. Tambahan, kajian terhadap ciri-ciri mekanikal berdasarkan tekanan, rekahan tensil dan kekuatan anjalan telah dijalankan. Dapatan kajian menunjukkan kesemua fiber yang digunakan menambah baik ciri-ciri mekanikal dan struktur konkrit. Tambahan lagi, walaupun fiber sintetik hibrid menunjukkan paling baik berbanding sampel contoh, fiber buangan (terutama RCW) menunjukkan pembaharuan ketara mencapai 30.91% berbanding beban maksimum dan masing-masing menunjukkan 10.1, 10.8 dan 14.4% pada tekanan, rekahan tensil dan kekuatan anjalan
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