152 research outputs found

    Developmental research of sustainable technologies to minimise problematic road embankment settlements

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    Challenging, problematic and non-uniform ground conditions are a night mare to geotechnical engineers tasked with the design and construction of buildings and transport infrastructure. These often suffer undesirable structural settlements. Designing within the current understanding of geotechnics; settlement in peat and organic soils need to be recognised to include the known “primary and secondary consolidation characteristics” and the lesser known “tertiary consolidation phase”. These eventually contribute cumulatively to the consequential uneven and hazardous “bumpy road” surfaces. Undulating flexible road pavements result primarily from the transference of the heavy self-weight of the embankment fill to yielding and non-uniform subgrade. The adoption of conventional design/repair methods such as pile, vertical drain, soil replacement and soil stabilisation are expensive and inappropriate in very soft ground conditions. These then lead to unjustifiably high and repetitive maintenance costs. There being no one quick fix solution for all; pragmatic research must necessarily identify the best/progressively improved practical and sustainable solution. A viable solution is to develop criteria and explore the concept of a “masonry arch bridge structure/lintel-column structure” and adopting sustainable materials through pragmatic searching for appropriate recyclable waste materials. This will lead to the basis for a sustainable, innovative, strong, stiff, permeable composite mat structure that can be used on soft and/or yielding ground conditions. Conceptual lightweight fill technology including the popularly used expanded polystyrene (EPS) and the innovative composite mats recently being developed by the research team are outlined

    Peningkatan Hasil Belajar Kimia Menggunakan Multimedia pada Materi Ikatan Kimia Kelas X Smk Negeri Parigi Selatan

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    This study aims to determine whether to use the multimedia macromedia flash points can increase the activity and learning achievement of students in the chemical bond subject at class X SMK South Parigi. The sample is a class X SMK south Parigi is 46 students. This research is the Classroom Action Research (PTK) type which was implemented in three cycles, where each cycle consists of four stages, namely: planning, implementation, observation, reflection. Data obtained from each cycle were analyzed to determine the corrective action in the next cycle. Data collection is carried out through a test which consists of post tests at each end of the learning cycle 1, 2, 3 and also interviews for the entire series of events during the activity, as well as the observation sheet activities of teachers and students of each meeting. The collected data were statistically analyzed using the average of the class, classical absorption, and the thoroughness of learning. On the cycle I the average value of 6.87, the absorption of classical learning 68.81% and 68.42% completeness, in the second cycle the average value was 7.73, 77.32 and 88.37% and classical absorption the completeness study on a third cycle of the average value was 8.23, the absorption of classical learning 82.33% and 93.33% completeness. While on the student activity, the cycle I get an average score of 27 which is an increase in the second cycle to 36 and 40 in cycle III with both criteria. Therefore, the use of power point and multimedia macromedia flash in learning can improve student learning activities and results

    Role of promoters in hoisting the catalytic performance for enhanced CO methanation

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    The increasing demand of natural gas and its rising cost have urged some countries to take initiatives to fulfil their energy needs. The production of substituted natural gas (SNG) by syngas (CO + H2) from coal or biomass is one of the most effective methods. As a promising source of energy, SNG has attracted much attention on research and applications due to the high demand for environmental protection. It is regarded as a clean energy source and an effective method for the application of coal resources, particularly in the regions with abundant coal resources but scarce natural gas such as in China [1-3]. SNG has attracted increasing attention due to its lower emission of sulphur and particulate matter. SNG is expected to be one of the main energy sources of the 21st century. It is environmentally friendly and less costly, has high calorific value, complete combustion, and smoke free compared to other energy sources. It has significant importance for the industrial level and transportation sectors

    Comparison of engagement and emotional responses of older and younger adults interacting with 3D cultural heritage artefacts on personal devices

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    The availability of advanced software and less expensive hardware allows museums to preserve and share artefacts digitally. As a result, museums are frequently making their collections accessible online as interactive, 3D models. This could lead to the unique situation of viewing the digital artefact before the physical artefact. Experiencing artefacts digitally outside of the museum on personal devices may affect the user's ability to emotionally connect to the artefacts. This study examines how two target populations of young adults (18–21 years) and the elderly (65 years and older) responded to seeing cultural heritage artefacts in three different modalities: augmented reality on a tablet, 3D models on a laptop, and then physical artefacts. Specifically, the time spent, enjoyment, and emotional responses were analysed. Results revealed that regardless of age, the digital modalities were enjoyable and encouraged emotional responses. Seeing the physical artefacts after the digital ones did not lessen their enjoyment or emotions felt. These findings aim to provide an insight into the effectiveness of 3D artefacts viewed on personal devices and artefacts shown outside of the museum for encouraging emotional responses from older and younger people

    Effect of ZSM-5 acidity in enhancement of methanol-to-olefins process

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    The skyrocketing demand for olefins especially propylene, have necessitated continuous efforts in finding alternate route for olefins production. Hence, methanol to olefins (MTO) was recognized as a feasible process since methanol could simply be mass produced from any gasifiable carbon-based feedstock, such as natural gas, coal, and biomass. Essentially, obtaining a more stable catalyst would improve economy of the MTO process. Acidity of catalyst has major influence in MTO, thus it is an indispensable parameter for conversion of methanol into value-added products. The present paper discusses the reactions involved in MTO process and the effect of acidity in enhancement of light olefin selectivity and catalytic stability. The paper also captured perspectives of crucial research and future direction for catalysts development and technologies that can potentiallly boost olefin production and make it competitive with the conventional olefin production processes

    A contemporary assessment on composite titania onto graphitic carbon nitride-based catalyst as photocatalyst

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    Titanium dioxide (TiO2) has drawn widespread interest by researchers as a precious semiconductor that is responsive towards photodegradation of various pollutants. This catalyst has its own limitations such as fast electron-hole recombination, wide band gap, and can only be utilised under ultraviolet (UV) region. In order to overcome these problems, the addition of a metal-free dopant is a common practice to prevent electron-hole recombination and enhance photodegradation under visible light. Among various types of metal-free catalysts, carbon nitride material has received much attention due to its numerous benefits such as good in terms of physical and chemical strength, as well as an attractive electronic band combined with a band gap (2.7 eV). This review summarised recent works in the development of titania incorporated with graphitic carbon nitride (g-C3N4) for enhanced photocatalytic activity

    Dendritic mesoporous Ni/KCC-1 for partial oxidation of methane to syngas

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    Depletion of fossil fuel for global energy system and increasing concern on global warming have driven the exploration of alternative and sustainable energy source in realms of academia and industry. This study aims to investigate the physicochemical features of KAUST Catalysis Center-1 supported catalyst (i.e., Ni/KCC-1) and evaluate its catalytic performance for Partial Oxidation of Methane (POM) reaction. N2 physisorption and XRD analyses confirmed the structural integrity of KCC-1 framework after NiO addition while the growth of Si-O-Ni bonds in KCC-1 structure was corroborated by the FTIR results. The FESEM and TEM images for KCC-1 not only affirm the successful formation of bicontinuous lamellar morphology but also reveal that the three-dimensional spherical structure was originally developed from the centre of microsphere into all axial. The combustion-reforming pathway was determined during reaction run and the H2/CO ratio ranging of 1.48 to 2.14 was appropriate for synthetic fuel production via Fischer-Tropsch synthesis (FTS)

    Epidemiological Features of Infantile Hypertrophic Pyloric Stenosis in Taiwanese Children: A Nation-Wide Analysis of Cases during 1997–2007

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    OBJECTIVE: To describe the epidemiological characteristics of infantile hypertrophic pyloric stenosis (IHPS) in ethnic Chinese children. MATERIALS AND METHODS: We reviewed the National Health Insurance claims database and analyzed data from children less than one year of age who had been diagnosed with IHPS (ICD-9-CM 750.5) and had undergone pyloromyotomy (ICD-9-CM 43.3). We analyzed the incidence, gender, age at diagnosis, length of hospital stay, seasonal variation and cost of IHPS from data collected between January 1997 and December 2007. RESULTS: A total of 1,077 infants met inclusion criteria, including 889 boys and 188 girls. The annual incidence of IHPS ranged from 0.30 to 0.47 per 1,000 live births with a mean incidence of 0.39 per 1,000 live births. Between 2002 and 2007, the incidence showed a declining trend (P = 0.025) with coincidentally increasing trends for both exclusive breastfeeding (P = 0.014) and breastfeeding plus bottle feeding (P = 0.004). The male-to-female rate ratio was dynamic and increased from 3.03 during the first two weeks of life to 8.94 during the 8(th) through 10th weeks of life. The overall male-to-female rate ratio was 4.30. The mean age at diagnosis was 43.1 ± 2.4 days. After analyzing the months of birth and hospital admission, no seasonal variation associated with IHPS was detected. The mean length of hospital stay was 8.28 ± 7.10 days. CONCLUSIONS: The incidence of IHPS in Taiwan, a country with a majority ethnic Chinese population, was lower than observed incidences in Caucasian populations living in Western countries. Breastfeeding campaigns and low maternal smoking rates may contribute to the lower incidence of IHPS in Taiwan. However, additional studies with longer follow-up periods are needed

    Venous thromboembolism in critically ill COVID-19 patients receiving prophylactic or therapeutic anticoagulation: a systematic review and meta-analysis

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    Many aspects of care such as management of hypercoagulable state in COVID-19 patients, especially those admitted to intensive care units is challenging in the rapidly evolving pandemic of novel coronavirus disease 2019 (COVID-19). We seek to systematically review the available evidence regarding the anticoagulation approach to prevent venous thromboembolism (VTE) among COVID-19 patients admitted to intensive care units. Electronic databases were searched for studies reporting venous thromboembolic events in patients admitted to the intensive care unit receiving any type of anticoagulation (prophylactic or therapeutic). The pooled prevalence (and 95% confidence interval [CI]) of VTE among patients receiving anticoagulant were calculated using the random-effects model. Subgroup pooled analyses were performed with studies reported prophylactic anticoagulation alone and with studies reported mixed prophylactic and therapeutic anticoagulation. We included twelve studies (8 Europe; 2 UK; 1 each from the US and China) in our systematic review and meta-analysis. All studies utilized LMWH or unfractionated heparin as their pharmacologic thromboprophylaxis, either prophylactic doses or therapeutic doses. Seven studies reported on the proportion of patients with the previous history of VTE (range 0–10%). The pooled prevalence of VTE among ICU patients receiving prophylactic or therapeutic anticoagulation across all studies was 31% (95% CI 20–43%). Subgroup pooled analysis limited to studies reported prophylactic anticoagulation alone and mixed (therapeutic and prophylactic anticoagulation) reported pooled prevalences of VTE of 38% (95% CI 10–70%) and 27% (95% CI 17–40%) respectively. With a high prevalence of thromboprophylaxis failure among COVID-19 patients admitted to intensive care units, individualised rather than protocolised VTE thromboprophylaxis would appear prudent at interim

    Wnt expression is not correlated with β-catenin dysregulation in Dupuytren's Disease

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    BACKGROUND: Dupuytren's contracture or disease (DD) is a fibro-proliferative disease of the hand that results in finger flexion contractures. Increased cellular β-catenin levels have been identified as characteristic of this disease. As Wnts are the most widely recognized upstream regulators of cellular β-catenin accumulation, we have examined Wnt gene expression in surgical specimens and in DD-derived primary cell cultures grown in two-dimensional monolayer culture or in three-dimensional FPCL collagen lattice cultures. RESULTS: The Wnt expression profile of patient-matched DD and unaffected control palmar fascia tissue was determined by a variety of complimentary methods; Affymetrix Microarray analysis, specific Wnt and degenerative primer-based Reverse Transcriptase (RT)-PCR, and Real Time PCR. Microarray analysis identified 13 Wnts associated with DD and control tissues. Degenerate Wnt RT-PCR analysis identified Wnts 10b and 11, and to a lesser extent 5a and 9a, as the major Wnt family members expressed in our patient samples. Competitive RT-PCR analysis identified significant differences between the levels of expression of Wnts 9a, 10b and 11 in tissue samples and in primary cell cultures grown as monolayer or in FPCL, where the mRNA levels in tissue > FPCL cultures > monolayer cultures. Real Time PCR data confirmed the down-regulation of Wnt 11 mRNA in DD while Wnt 10b, the most frequently isolated Wnt in DD and control palmar fascia, displayed widely variable expression between the methods of analysis. CONCLUSION: These data indicate that changes in Wnt expression per se are unlikely to be the cause of the observed dysregulation of β-catenin expression in DD
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