19672 research outputs found
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Properties of metakaolin-blended oil palm shell lightweight concrete
No full textIn this paper, the effect of partial replacement of cement with metakaolin (MK) on the strength properties of oil palm shell (OPS) lightweight concrete was investigated. Generally, 5–20% of partial cement replacement with MK enhanced the compressive, splitting tensile and flexural strengths as well as modulus of elasticity of OPS concrete (OPSC). Though the 28 day compressive strength of the OPSC was found in the range of 39–47 MPa, the highest compressive strength was obtained for the mix with 10% replacement of MK. Similar replacement level of MK was found optimum for both the splitting tensile and flexural strengths. In addition, the strength efficiency of OPSC with MK as partial cement replacement was also investigated and it was found that the increase in the replacement level of MK up to 20% resulted in 49% increase in the strength efficiency for the OPSC
Post-war tourism as an urban reconstruction strategy case study: Khorramshahr
No full textPurpose: Tourism development has been perceived as a promoter of city restoration and can also affect the post-war city reconstruction. Questions on how to reconstruct ruined buildings and urban areas through a post-war tourism-oriented approach based on the expectations of residents and tourists profound answers. The purpose of this paper is to adopt the sequential mixed method (qualitative and quantitative) with purposive sampling which is a non-probability method to investigate tourism-oriented approaches in the reconstruction of buildings and landmarks as the core components of urban tourism. Design/methodology/approach: The study adopted the sequential mixed method (qualitative and quantitative) to investigate tourism-oriented approaches in the reconstruction of buildings and landmarks as the core components of urban tourism. Findings: The findings of the study point that the preferred strategy for the reconstruction of damaged symbolic building is the preservation of the war effects in regard maintaining the buildings’ history to be considered by urban policy makers, urban designers, and authorities. Research limitations/implications: The constraint was associated with the time-consuming nature of this type of research. Original documents of the research context and all the interview data were in the Persian language, making the translating process a time-consuming matter. Furthermore, data collection in the area located near the Iran-Iraq border (500 meters) presented a number of security caveats as limitations. Originality/value: The research found a majority of tourists and the residents preferred tourism zone where the combination of post-war and natural attraction across riverside area. In other word, most considerable post-war attractions are those that combined with the appeal of the other tourism potentials like eco-leisure tourism. The preferred strategy for the reconstruction of damaged building reconstruction as post-war tourism attractions is the preservation of the war effects in regard maintaining the buildings history rather than reconstruction as the most likely to pre-war conditions with less attention paid to the war effects
A Blowout Jet Associated with One Obvious Extreme-ultraviolet Wave and One Complicated Coronal Mass Ejection Event
No full textIn this paper, we present a detailed analysis of a coronal blowout jet eruption that was associated with an obvious extreme-ultraviolet (EUV) wave and one complicated coronal mass ejection (CME) event based on the multiwavelength and multi-view-angle observations from the Solar Dynamics Observatory and the Solar Terrestrial Relations Observatory. It is found that the triggering of the blowout jet was due to the emergence and cancellation of magnetic fluxes on the photosphere. During the rising stage of the jet, the EUV wave appeared just ahead of the jet top, lasting about 4 minutes and at a speed of 458-762 km s-1. In addition, obvious dark material is observed along the EUV jet body, which confirms the observation of a mini-filament eruption at the jet base in the chromosphere. Interestingly, two distinct but overlapped CME structures can be observed in corona together with the eruption of the blowout jet. One is a narrow jet shape, while the other one is a bubble shape. The jet-shaped component was unambiguously related to the outwardly running jet itself, while the bubble-like one might either be produced due to the reconstruction of the high coronal fields or by the internal reconnection during the mini-filament ejection according to the double-CME blowout jet model first proposed by Shen et al., suggesting more observational evidence should be supplied to clear the current ambiguity based on large samples of blowout jets in future studies
Effect of size on single and double optical microbottle resonator humidity sensors
No full textAn experimental study on the effect of whispering gallery mode (WGMs) on micro-bottle resonator (MBR) and its application on humidity sensing is presented. Different transmission mode spectra observed when the diameter of MBR (Db) change from 130μm to 190μm. The Q-factor for single and double MBRs ware observed >104 for all cases. The size and number of MBRs effecting Q-factor value which are high Q-factor value for smallest size Db=130μm for single MBR and Pair-4 (combination of two biggest MBRs Db=190μm) for double MBRs. Application of single and double MBRs in humidity sensing received various sensing performance. With the highest sensitivity value, linearity >90% and P-value >10-13 make MBR with diameter 130μm to be the best performance as humidity sensor for all cases. Both single and double MBRs are stable over 60 seconds. Overall, the size of the MBR has been shown to be more important than the quantity of MBRs for humidity sensing. Indeed, double MBRs actually perform worse than single MBRs as humidity sensors
Survival and Associated Risk Factors for Mortality Among Infants with Critical Congenital Heart Disease in a Developing Country
No full textCritical congenital heart disease (CCHD) is associated with significant morbidity and mortality. However, data on survival of CCHD and the risk factors associated with its mortality are limited. This study examined CCHD survival and the risk factors for CCHD mortality. Using a retrospective cohort study of infants born with CCHD from 2006 to 2015, survival over 10 years was estimated using Kaplan–Meier analysis, and the risk factors for mortality were analyzed using multivariate Cox proportional hazards regression. A total of 491 CCHD cases were included in the study, with an overall mortality rate of 34.8% (95% confidence interval [CI] 30.6–39.2). The intervention/surgical mortality rate was 9.8% ≤ 30 days and 11.5% > 30 days after surgery, and 17% died before surgery or intervention. The median age at death was 2.7 months [first quartile: 1 month, third quartile: 7.3 months]. The CCHD survival rate was 90.4% (95% CI 89–91.8%) at 1 month, 69.3% (95% CI 67.2–71.4%) at 1 year, 63.4% (95% CI 61.1–65.7%) at 5 years, and 61.4% (95% CI 58.9–63.9%) at 10 years. Weight of < 2 kg at diagnosis, associated syndromes, poor pre-operative condition, and non-duct-dependent CCHD were independent risk factors for poor survival, with hazard ratios of 2.61, 2.10, 2.22, and 1.70, respectively. CCHD is associated with a high mortality rate. Low weight, poor pre-operative condition, associated syndromes, and non-duct-dependent CCHD are significant risk factors affecting the survival of infants with CCHD
Community responses to flood risk management – An empirical Investigation of the Marine Protected Areas (MPAs) in Malaysia
No full textThe vulnerability of the Marine Protected Areas (MPAs) to flood disasters affects not only the underlying eco-centric and anthropocentric values therein, but also the coastal communities that are adjacent to the MPAs. The consequences can lead to economic, social and environmental degradation. As such, the perception of the coastal communities about flood risk occurrences and their effects on the MPAs are crucial for Flood Risk Management (FRM) exercises. Having an insight into the perceptions of the coastal communities about the build-up of flood risk analysis adds robustness to the FRM cycle as it can increase levels of preparedness, responses and recoveries. This paper examines the relationship between the communities’ perceived vulnerability, perceived severity of flood risks, perceived benefits of flood risk management, perceived barriers of flood management and their previous experience of flood risk management. The paper seeks to understand how this intersection influences the human intention to participate in the preventive and precautionary measures related to flood risks in MPAs. To achieve the objectives, a survey questionnaire was conducted on a sample of 320 households from MPAs in Malaysia. Data were analysed using the structural equation modelling (SEM). This study revealed that perceived susceptibility, perceived severity, perceived benefits, and previous flood risk experience have a positive and significant influence on the intention to participate in prevention activities. This study offers valuable insights that may be useful for policymakers in promoting greater public engagement in managing climatic disasters including potential flood risks in MPAs
Effect of Vermicompost Amendment on Nutritional Status of Sandy Loam Soil, Growth Performance, and Yield of Pineapple (Ananas comosus var. MD2) under Field Conditions
No full textVermicompost is the product of composting or breaking down organic matter through the use of earthworms. It is rich in essential plant nutrients, and has the ability to enhance the condition and increase the quality of the soil. In the present study, a field trial was conducted from January 2015 until March 2016 to elucidate the effects of vermicompost application (compared to supplementation with chemical fertilizer and no fertilizer) on the sandy loam soil and plant nutrients of pineapple (Ananas comosus var. MD2). The morphophysiology and yield performance of MD2 pineapple grown with vermicompost in the field were also evaluated. In this study, vermicompost was applied onto the sandy loam soils during transplanting, followed by a second application at seven MAP (months after planting) at the rate of 10 t ha− 1. On the other hand, the chemical fertilizer was applied based on the normal conventional cultivation practice. The soil and D-leaf samples at six MAP (S1) and during the red bud stage (S2; 10 MAP) were used to determine the soil and plant nutrient contents. The morphology of the plants was evaluated every month, and the fruits that were produced were subjected to quality analysis. Data analysis revealed that soil pH was increased after a second supplementation of vermicompost and contained significantly higher total N (0.15%) in the soils compared to the control (0.07%). There was no significant difference between plants supplied with chemical fertilizer and vermicompost in terms of plant height, number of leaves, or the length and width of D-leaves. However, different fertilization treatments were found to affect the yield and physical characteristics of the resulting fruits. Plants supplied with chemical fertilizer produced the highest fruit yield (136.97 t ha− 1) with the largest fruit size, followed by vermicompost (121.39 t ha− 1) and the control (94.93 t ha− 1). However, fruits supplied with vermicompost were observed to have the smallest crowns. Taken together, these results indicated that the use of vermicompost produced pineapple plants with excellent growth performance, comparable to that obtained when chemical fertilizer was used. Also, based on the cost analysis conducted, it was shown that the total cost (fertilizer and labor) for plants grown with vermicompost was lower than plants grown with chemical fertilizer. However, the usage of vermicompost as the single source of nutrients is not suggested for this type of soil and field conditions, but can be used as a supplement to maintain the soil quality and ensure agricultural sustainability
Unravelling pH-responsive behaviour of Fe 3 O 4 @CNCs-stabilized Pickering emulsions under the influence of magnetic field
No full textThe pH-responsive characteristic of Fe3O4@CNC (MCNC)-stabilized Pickering emulsions (MCNC-PEs) under the influence of an external magnetic field were investigated. The Pickering emulsions were prepared using MCNC nanocomposites as the emulsifier. The results demonstrated that the MCNC-PEs exhibited reversible pH-dependent stability that was affected by the presence of magnetic fields. The MCNC-PE droplets prepared with 0.3 wt% MCNC was observed to be stable in acidic solution (pH 1.5–5.0) but broken down in alkaline medium (pH ≥ 7.5). This phenomenon could be owing to an abrupt change of MCNC wetting properties as resulted by the combined effects of superparamagnetic hysteresis and high solubility of MCNCs in alkaline environment. The formulated emulsion can be cycled between stable and unstable 3 times upon a simple pH variation. The unique pH-dependent stability was, however, not observed in the emulsion systems prepared using 0.5 wt% MCNCs, suggesting that MCNC-PE with higher degree of surface coverage by MCNC particles were highly stable against both pH changes and magnetic field. This study revealed the reversible inter-droplet stability of MCNC-PEs upon changes in pH with the presence of magnetic field, therefore these engineered emulsions could find potential applications in encapsulation and controlled release of pharmaceutically active compounds
Differentiating extensor plantar response in pathological and normal population
No full textIntroduction: Approximately 5%-11% of neurologically normal population has extensor plantar response (EPR). Method: This study is aimed to identify differentiating features of EPR between physiological and pathological population. Results: A total of 43 patients with pyramidal lesions and 113 normal controls were recruited for this study. The pathological EPRs were more reproducible, with 89.4% having at least two positive Babinski responses and 91.5% having two positive Chaddock responses (vs. 14.3% and 4.8% in controls, P < 0.001). The pathological EPR was more sensitive to stimulation, in which 89.1% were elicited when the stimulation reached mid-lateral sole (vs. 11.9% in controls, P < 0.001). Most (93.6%) pathological cases had sustained big toe extension throughout stimulation (vs. 73.8% in controls, P < 0.001). As compared to those with brain lesion, the plantar responses in those with spinal lesion are less likely to have ankle dorsiflexion (5.3% vs. 25%, P < 0.05) more likely to have sustained extensor response with Babinski (94.7% vs. 71.4%, P < 0.05), Chaddock (89.5% vs. 64.3%, P < 0.05), and Schaefer (26.3% vs. 3.6%, P < 0.05) methods. A scoring system was computed using four variables, i.e., two consecutive positive Babinski or Chaddock responses, extensor response at mid-lateral sole, and sustained extension throughout stimulation. A score ≥3 is predictive of pathological origin, with sensitivity and specificity of 78.7% and 95.2%, respectively. Conclusion: The pathological EPR is more reproducible, sensitive to stimulation, and sustainable compared to physiological extensor response
Epidemiology, clinical presentation and respiratory sequelae of adenovirus pneumonia in children in Kuala Lumpur, Malaysia
No full textObjectives To describe the severity, human adenovirus (HAdV) type and respiratory morbidity following adenovirus pneumonia in children. Methodology Retrospective review of children under 12 years of age, admitted with HAdV pneumonia, between January 2011 and July 2013, in a single centre in Malaysia. HAdV isolated from nasopharyngeal secretions were typed by sequencing hypervariable regions 1–6 of the hexon gene. Patients were reviewed for respiratory complications. Results HAdV was detected in 131 children of whom 92 fulfilled inclusion criteria. Median (range) age was 1.1 (0.1–8.0) years with 80% under 2 years. Twenty percent had severe disease with a case-fatality rate of 5.4%. Duration of admission (p = 0.02) was independently associated with severe illness. Twenty-two percent developed respiratory complications, the commonest being bronchiolitis obliterans (15.2%) and recurrent wheeze (5.4%). The predominant type shifted from HAdV1 and HAdV3 in 2011 to HAdV7 in 2013. The commonest types identified were types 7 (54.4%), 1(17.7%) and 3 (12.6%). Four out of the five patients who died were positive for HAdV7. Infection with type 7 (OR 8.90, 95% CI 1.32, 59.89), family history of asthma (OR 14.80, 95% CI 2.12–103.21) and need for invasive or non-invasive ventilation (OR 151.84, 95% CI 9.93–2.32E) were independent predictors of respiratory complications. Conclusions One in five children admitted with HAdV pneumonia had severe disease and 22% developed respiratory complications. Type 7 was commonly isolated in children with severe disease. Family history of asthma need for invasive or non-invasive ventilation and HAdV 7 were independent predictors of respiratory complications