33 research outputs found

    Structural behaviour of an innovative precast cold-formed steel ferrocement as composite beam

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    This research investigates the structural behaviour of simply supported composite beams, in which a ferrocement slab is connected together with cold-formed steel (CFS) beam by means of shear connectors. This system, called Precast Cold- Formed Steel-Ferrocement Composite Beam System, is designed to utilise the composite action between the CFS sections and ferrocement slab where shear forces are effectively transmitted between the beam and slab via shear connectors.CFS sections have been recognized as an important structural element in developed countries, and sustainable construction material for low rise residential and commercial buildings. However, it still is remains as insufficient data and information on the behaviour and performance of CFS as the composite construction in composite action is yet to be established. One limiting feature of CFS is the thickness of this section that makes it susceptible to torsional, distortional, lateral torsional, lateral distortional and local buckling. Hence, a reasonable solution is resorting composite construction of structural CFS section integrated with reinforced concrete deck slab. An efficient and innovative beam system of built-up CFS sections acting compositely with a concrete deck slab has been developed to provide an alternative composite system for floors and roofs in buildings. In this study, ferrocement is an alternative solution as concrete deck of a slab. It is a form of thin reinforced concrete structure, in which a strong cement-sand mortar matrix is reinforced with closely spaced, multiple layers of thin wire mesh or small diameter rods, uniformly dispersed throughout the matrix of the composite. This study mainly comprises three major components; experimental work, theoretical analysis and finite element analysis using ANSYS (version 11). Experimental works involved small-scale and full-scale testing of laboratory tests. The first phase of test program comprised often push-out test specimens and eighteen full-scale CFS-ferrocement composite beam specimens. Push-out tests were carried out to determine the strength and behaviour of the shear transfer enhancement between the CFS and ferrocement.Three types of shear connectors (bolts, self-drilling screws, bar angle) were tested and 2, 4 and 6 layers of wire mesh in ferrocement cold formed were proposed. The expression for predicting the capacity of shear connector in which bolt with 12mm diameter is best to be considered to transfer shear force into steel section-ferrocement slab interface. The second phase of test program comprised of a total of eighteen full-scale simply supported composite beams with variable parameters and tested to failure. The main variables considered in the study are the shape of section (I- and C-section as beam), thickness (2mm, 3mm and 4mm) of the CFS section and number of wire mesh layer (2, 4 and 6 layers). Four points load bending system was used to test the specimens. The plastic analysis results depicted that the ultimate bending capacity of a ferrocement CFS composite beam can be estimated by using conventional equilibrium procedures and the constitutive laws prescribed by Euro codes. The finite element and theoretical model showed agreement with the experimental results based on the moment versus deflection curves of the proposed composite beam system

    Methods of financing waqf development in Singapore = أساليب تمويل تطوير األوقاف في سنغافورة

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    The Waqf sector in the Muslim world suffers in general from a state of negligence, and a lack of tactics and strategies in taking advantage of it, which results from cumulative and overlapping factors. This phenomenon invites for an investigation of successful Waqf experiences around the world, of which Singapore is the pioneer in it. The Waqf experience in Singapore is considered one of the most successful experiments at the Muslim world level, both in terms of the organization, and the investment. The sector has witnessed a remarkable development as effective modern methods and techniques were discovered. The study aims to reveal the reality of this experience, which includes the following Waqf funds: funds for mosques, funds for the handicapped, Quran memorization, as well as education, scientific research, innovation and others. However, the monetary Waqf has gained popularity in the sector, unlike the Waqf of immovable assets. Muslims in Singapore have realized the importance of the monetary Waqf and its role in collecting social savings, converting them into social capital, and developing the social capital market; to stimulate the merging between social security and social care, and to achieve the legitimate objectives of the Waqf and public interests. The Waqf administration in Singapore has used Sukuk to develop some of its endowments (Waqfs), therefore, the study will address how the Waqf in Singapore has benefited from this method in financing the development of endowments in both the construction project of a building on Beach Road 11, and a project to raise $ 35 million for the project to develop Waqf assets on Street Bencoolen. The researcher has employed both a case study as well as a descriptive analytical approach

    Qatar experience on One Health approach for middle-east respiratory syndrome coronavirus, 2012-2017: A viewpoint

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    The emergence of the Middle East Respiratory Syndrome Corona Virus (MERS-CoV) in the Middle East in 2012 was associated with an overwhelming uncertainty about its epidemiological and clinical characteristics. Once dromedary camels (Camelus dromedarius) was found to be the natural reservoir of the virus, the public health systems across the Arabian Peninsula encountered an unprecedented pressure to control its transmission. This view point describes how the One Health approach was used in Qatar to manage the MERS-CoV outbreak during the period 2012–2017. One Health focuses on the association between the human, animals and environment sectors for total health and wellbeing of these three sectors. To manage the MERS outbreak in Qatar through a One Health approach, the Qatar National Outbreak Control Taskforce (OCT) was reactivated in November 2012. The animal health sector was invited to join the OCT. Later on, technical expertise was requested from the WHO, FAO, CDC, EMC, and PHE. Subsequently, a comprehensive One Health roadmap was delivered through leadership and coordination; surveillance and investigation; epidemiological studies and increase of local diagnostic capacity. The joint OCT, once trained had easy access to allocated resources and high risk areas to provide more evidence on the potential source of the virus and to investigate all reported cases within 24–48 h. Lack of sufficient technical guidance on veterinary surveillance and poor risk perception among the vulnerable population constituted major obstacles to maintain systematic One Health performance

    Middle East respiratory syndrome coronavirus in dromedary camels: An outbreak investigation

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    Background: Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe lower respiratory tract infection in people. Previous studies suggested dromedary camels were a reservoir for this virus. We tested for the presence of MERS-CoV in dromedary camels from a farm in Qatar linked to two human cases of the infection in October, 2013. Methods: We took nose swabs, rectal swabs, and blood samples from all camels on the Qatari farm. We tested swabs with RT-PCR, with amplification targeting the E gene (upE), nucleocapsid (N) gene, and open reading frame (ORF) 1a. PCR positive samples were tested by different MERS-CoV specific PCRs and obtained sequences were used for phylogentic analysis together with sequences from the linked human cases and other human cases. We tested serum samples from the camels for IgG immunofluorescence assay, protein microarray, and virus neutralisation assay. Findings: We obtained samples from 14 camels on Oct 17, 2013. We detected MERS-CoV in nose swabs from three camels by three independent RT-PCRs and sequencing. The nucleotide sequence of an ORF1a fragment (940 nucleotides) and a 4·2 kb concatenated fragment were very similar to the MERS-CoV from two human cases on the same farm and a MERS-CoV isolate from Hafr-Al-Batin. Eight additional camel nose swabs were positive on one or more RT-PCRs, but could not be confirmed by sequencing. All camels had MERS-CoV spike-binding antibodies that correlated well with the presence of neutralising antibodies to MERS-CoV. Interpretation: Our study provides virological confirmation of MERS-CoV in camels and suggests a recent outbreak affecting both human beings and camels. We cannot conclude whether the people on the farm were infected by the camels or vice versa, or if a third source was responsible. Funding: European Union projects EMPERIE (contract number 223498), ANTIGONE (contract number 278976), and the VIRGO consortium

    The sample of choice for detecting Middle East respiratory syndrome coronavirus in asymptomatic dromedary camels using real-time reverse-transcription polymerase chain reaction

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    The newly identified Middle East respiratory syndrome coronavirus (MERS-CoV), which causes severe respiratory disease, particularly in people with comorbidities, requires further investigation. Studies in Qatar and elsewhere have provided evidence that dromedary camels are a reservoir for the virus, but the exact modes of transmission of MERS-CoV to humans remain unclear. In February 2014, an assessment was made of the suitability and sensitivity of different types of sample for the detection of MERS-CoV by real-time reverse-transcription polymerase chain reaction (RT-PCR) for three gene targets: UpE (upstream of the E gene), the N (nucleocapsid) gene and open reading frame (ORF) 1a. Fifty-three animals presented for slaughter were sampled. A high percentage of the sampled camels (79% [95% confidence interval 66.9-91.5%, standard error 0.0625]; 42 out of 53) were shown to be shedding MERS-CoV at the time of slaughter, yet all the animals were apparently healthy. Among the virus-positive animals, nasal swabs were most often positive (97.6%). Oral swabs were the second most frequently positive (35.7%), followed by rectal swabs (28.5%). In addition, the highest viral load, expressed as a cycle threshold (Ct) value of 11.27, was obtained from a nasal swab. These findings lead to the conclusion that nasal swabs are the candidate sample of choice for detecting MERS-CoV using RT-PCR technology in apparently healthy camels

    Occupational exposure to dromedaries and risk for MERS-CoV infection, Qatar, 2013–2014

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    We determined the presence of neutralizing antibodies to Middle East respiratory syndrome coronavirus in persons in Qatar with and without dromedary contact. Antibodies were only detected in those with contact, suggesting dromedary exposure as a risk factor for infection. Findings also showed evidence for substantial underestimation of the infection in populations at risk in Qatar

    Isolation of MERS coronavirus from dromedary camel, Qatar, 2014

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    We obtained the full genome of Middle East respiratory syndrome coronavirus (MERS-CoV) from a camel in Qatar. This virus is highly similar to the human England/ Qatar 1 virus isolated in 2012. The MERS-CoV from the camel efficiently replicated in human cells, providing further evidence for the zoonotic potential of MERS-CoV from camels

    The impact of dietary intake and exercise on metabolic health in Saudi Arabian women

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