Drag-Reduction Study and its Dynamic Characteristics on Recreational Speedboat Utilizing Simplified Shark Skin Design

Inspired by the structure of the shark skin denticles, our team has carried out a study on the attempt of improving the hydrodynamic design of marine vessels through design modification on the hull form by applying simplified imitation of shark skins. Speedboat models used in this study were designed using computer-aided design (CAD) software and computational fluid dynamic (CFD) simulations were then carried out to predict the hydrodynamic effect of the bio mimicry application on the hull form, mainly focusing on the wave profile produced by the models as well as the total drag experienced by it under two different Froude value; Fr≈ 0.39 and Fr≈0.47. Interestingly, the design modification on the hull gave encouraging results with a reduction of 12% and 10.4% at Fr≈ 0.39 and Fr≈0.47 respectively on the total drag coefficient. Furthermore, the modified speedboat provides better wave pattern compared to unmodified hull form. The reduction of drag force could contribute to a more efficient vessel with better cruising speed. Thus, this provide better impact to marine industry in order to help improve their vessel dynamic performances

Development of an indoor air quality checklist for risk assessment of indoor air pollutants by semiquantitative score in nonindustrial workplaces

Background: To meet the current diversified health needs in workplaces, especially in nonindustrial workplaces in developing countries, an indoor air quality (IAQ) component of a participatory occupational safety and health survey should be included. Objectives: The purpose of this study was to evaluate and suggest a multidisciplinary, integrated IAQ checklist for evaluating the health risk of building occupants. This IAQ checklist proposed to support employers, workers, and assessors in understanding a wide range of important elements in the indoor air environment to promote awareness in nonindustrial workplaces. Methods: The general structure of and specific items in the IAQ checklist were discussed in a focus group meeting with IAQ assessors based upon the result of a literature review, previous industrial code of practice, and previous interviews with company employers and workers. Results: For practicality and validity, several sessions were held to elicit the opinions of company members, and, as a result, modifications were made. The newly developed IAQ checklist was finally formulated, consisting of seven core areas, nine technical areas, and 71 essential items. Each item was linked to a suitable section in the Industry Code of Practice on Indoor Air Quality published by the Department of Occupational Safety and Health. Conclusion: Combined usage of an IAQ checklist with the information from the Industry Code of Practice on Indoor Air Quality would provide easily comprehensible information and practical support. Intervention and evaluation studies using this newly developed IAQ checklist will clarify the effectiveness of a new approach in evaluating the risk of indoor air pollutants in the workplace

Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42\ub74% vs 44\ub72%; absolute difference \u20131\ub769 [\u20139\ub758 to 6\ub711] p=0\ub767; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5\u20138] vs 6 [5\u20138] cm H2O; p=0\ub70011). ICU mortality was higher in MICs than in HICs (30\ub75% vs 19\ub79%; p=0\ub70004; adjusted effect 16\ub741% [95% CI 9\ub752\u201323\ub752]; p<0\ub70001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0\ub780 [95% CI 0\ub775\u20130\ub786]; p<0\ub70001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status. Funding: No funding

Cultural heritage preservation efforts in Malaysia: A survey

Malaysia, just like its neighbouring countries in the region, has a rich and diverse culture and heritage treasures. What makes Malaysia more unique is its diversity as a multi-racial and multicultural country. These cultural heritages might become lost and extinct without any efforts in preserving and safeguarding due to modernization, assimilation, and globalization. We present an overview of different cultural heritage in Malaysia and available efforts to preserve these treasures found from literature. Digital preservation efforts that computer graphics, media scientists and practitioners could offer as alternatives in preservation of culture and heritage preservation will also be included in this paper

Entropy generation minimization of two-phase flow in a mini channel with genetic algorithm

Performance of the two-phase flow in a minichannel had in the past been measured by the pressure drop or/and heat transfer coefficient. The desired low pressure drop across a small channel follows a low heat transfer coefficient. Optimization of the two-phase flow system is generally achieved either experimentally through discrete variations of each of the parameters involved while holding the rest constant, or numerically which is also possible through a parametric study. The objective of this study was to investigate the thermodynamic performance in terms of entropy generation minimization (EGM) of two-phase flow of ammonia, R22, and R134A in a 3-mm minichannel using a random search technique, genetic algorithm. The EGM performance and the optimization approach have never been attempted before. R22 has been identified as a hazardous refrigerant and alternatives are being investigated with performance as good if not better. In this study, under the optimization of the mass flux and vapour quality at the saturation temperature of 10C, simultaneous minimization of the entropy generation and maximization of the heat transfer coefficient showed that between 250 and 450 kg/m2s, ammonia has a much higher heat transfer coefficient than R22 and R134A, and at a lower quality but with very high entropy generation. Furthermore, ammonia has many sets of optimal solutions, several combinations of entropy generation and heat transfer coefficient under optimized heat flux operation and vapour quality. R22 and R134A have their optimized heat transfer coefficients over a limited range and which occurred beyond the quality of 0.8. The study has shown that ammonia could be the replacement refrigerant to R22 and R134A in terms of heat transfer but at the expense of a higher entropy generation rat

Design and development of learning mathematics game for primary school using handheld augmented reality

The traditional learning methods have some drawbacks and limitation such as restricted learning space, high cost, and lack of student engagement. In the era of digitalization, traditional education starts to transform into a more dynamic and modern education with the influence of the 21st-century learning method. Moreover, due to the pandemic, schools and universities are moving to digital learning to contain the spread of Coronavirus Disease 2019 (COVID-19). Therefore, the aim of this project is to develop a Mathematics game using handheld Augmented Reality (HAR) for primary school children as an alternative method in learning Mathematics. There are three main phases have been carried out, first is to study the requirements of an educational game. The second phase involves the design and development including the game element, storyline, game characters as well as user interface design. Finally, the third phase is integrating the learning Mathematics game using HAR, followed by evaluation. The evaluation of the learning Mathematics game was carried out for usability and user acceptance. The usability results show that the users are satisfied with the prototype and feedbacks show the game is fun. Overall, this project has successfully produced a learning Mathematics game using HAR for primary school children

Methodology To Produce Hard Coherent Water Adsorbent Using Modified Fusion Method

Keywords: spent bleaching earth, water adsorbent, modified fusion method, ethanol water mixture Efforts were given to find suitable method to produce hard and coherent water adsorbent for ethanol water mixture. Three methods were studied. In the first method, calcined clay was mixed with alumina and KOH or NaOH. Water was added to get 40 -50% solution and thoroughly mixed. The mixture was aged for 48 hours in closed container at 38 o C followed by crystallization. In the second method, calcined clay or pure silica and alumina sources were mixed with NaOH or KOH and fused in furnace at 550 o C for 12 hours. The fused mixture was mixed with water to get 40-55% solution of KOH or NaOH. Aging was carried out at 38 o C for 48 hours before crystallization took place. In the third method, fused mixture from method 2 was mixed with NaOH or KOH and 5 part of water. The mixture was vigorously stirred for 3 hours and left for aging/crystallization at 60 o C for 24 hours in oven. All the products from the three methodologies were washed and dried before being tested for water adsorbance. Results showed that method 2 was able to produce water adsorbent. The experimental results also revealed that the repetition of reflux may improve the water adsorbance performance of the adsorbent. However XRD analysis showed that the product was not the type of zeolite A

Analysis of indoor air pollutants checklist using environmetric technique for health risk assessment of sick building complaint in nonindustrial workplace

Purpose: To analyze and characterize a multidisciplinary, integrated indoor air quality checklist for evaluating the health risk of building occupants in a nonindustrial workplace setting. Design: A cross-sectional study based on a participatory occupational health program conducted by the National Institute of Occupational Safety and Health (Malaysia) and Universiti Putra Malaysia. Method: A modified version of the indoor environmental checklist published by the Department of Occupational Health and Safety, based on the literature and discussion with occupational health and safety professionals, was used in the evaluation process. Summated scores were given according to the cluster analysis and principal component analysis in the characterization of risk. Environmetric techniques was used to classify the risk of variables in the checklist. Identification of the possible source of item pollutants was also evaluated from a semiquantitative approach. Result: Hierarchical agglomerative cluster analysis resulted in the grouping of factorial components into three clusters (high complaint, moderate-high complaint, moderate complaint), which were further analyzed by discriminant analysis. From this, 15 major variables that influence indoor air quality were determined. Principal component analysis of each cluster revealed that the main factors influencing the high complaint group were fungal-related problems, chemical indoor dispersion, detergent, renovation, thermal comfort, and location of fresh air intake. The moderate-high complaint group showed significant high loading on ventilation, air filters, and smoking-related activities. The moderate complaint group showed high loading on dampness, odor, and thermal comfort. Conclusion: This semiquantitative assessment, which graded risk from low to high based on the intensity of the problem, shows promising and reliable results. It should be used as an important tool in the preliminary assessment of indoor air quality and as a categorizing method for further IAQ investigations and complaints procedures