42 research outputs found
PRODUCTION OF PARTICLE BOARDS USING POLYSTYRENE AND BAMBOO WASTES
This investigation was able to produce incredibly strong particleboards using bamboo and resinous material obtained from Polystyrene wastes. The particleboards were prepared by mixing the bamboo fibres and Polystyrene based resin (PBR) followed by flat press process at different ratio (v/v). Physical properties were measured, with reference to normal and oven curing methods, according to the ASTM D-1037 standard. Thickness Swelling (TS) of the samples were measured after 2 and 24 hours of immersion in water at 25oC temperature. It was found that the physical properties of particleboards with 20%, 30% and 40% PBR content were all in agreement with low density particleboard classification of American National Standards Institute (ANSI). TS increased as the PBR content decreased in the matrix. Obtained properties convincingly indicate superior bonding ability of the synthesised resinous polystyrene over known industrial adhesives typically used for particleboard production. http://dx.doi.org/10.4314/njt.v36i3.18Â
Thermal Cracking of Low Density Polyethylene (LDPE) Waste into Useful Hydrocarbon Products
Waste low density polyethylene film (table water sachets) was converted into solid, liquid oil and gaseous products by thermal process in a self- designed stainless steel laboratory reactor. The waste polymer was completely pyrolized within the temperature range of 474 – 520°C and 2hours reaction time. The solid residue obtained exhibits the characteristics of grease which is totally dissimilar to the plastic characteristics of the waste polymer fed into the reactor. Liquid fuel oil is rich in paraffins and olefins containing C8-C24 hydrocarbons. The gaseous product (suspected to be lower hydrocarbons in the range C1-C4) was eluted without collection. The liquid oil product was analyzed by GC/MS technique.Keywords: Low density polyethylene, Pyrolysis, Thermal crackin
Intelligent judgements over health risks in a spatial agent-based model
© 2018 The Author(s). Background: Millions of people worldwide are exposed to deadly infectious diseases on a regular basis. Breaking news of the Zika outbreak for instance, made it to the main media titles internationally. Perceiving disease risks motivate people to adapt their behavior toward a safer and more protective lifestyle. Computational science is instrumental in exploring patterns of disease spread emerging from many individual decisions and interactions among agents and their environment by means of agent-based models. Yet, current disease models rarely consider simulating dynamics in risk perception and its impact on the adaptive protective behavior. Social sciences offer insights into individual risk perception and corresponding protective actions, while machine learning provides algorithms and methods to capture these learning processes. This article presents an innovative approach to extend agent-based disease models by capturing behavioral aspects of decision-making in a risky context using machine learning techniques. We illustrate it with a case of cholera in Kumasi, Ghana, accounting for spatial and social risk factors that affect intelligent behavior and corresponding disease incidents. The results of computational experiments comparing intelligent with zero-intelligent representations of agents in a spatial disease agent-based model are discussed. Methods: We present a spatial disease agent-based model (ABM) with agents' behavior grounded in Protection Motivation Theory. Spatial and temporal patterns of disease diffusion among zero-intelligent agents are compared to those produced by a population of intelligent agents. Two Bayesian Networks (BNs) designed and coded using R and are further integrated with the NetLogo-based Cholera ABM. The first is a one-tier BN1 (only risk perception), the second is a two-tier BN2 (risk and coping behavior). Results: We run three experiments (zero-intelligent agents, BN1 intelligence and BN2 intelligence) and report the results per experiment in terms of several macro metrics of interest: an epidemic curve, a risk perception curve, and a distribution of different types of coping strategies over time. Conclusions: Our results emphasize the importance of integrating behavioral aspects of decision making under risk into spatial disease ABMs using machine learning algorithms. This is especially relevant when studying cumulative impacts of behavioral changes and possible intervention strategies
Risk perception and behavioral change during epidemics: Comparing models of individual and collective learning
Copyright © 2020 Abdulkareem et al. Modern societies are exposed to a myriad of risks ranging from disease to natural hazards and technological disruptions. Exploring how the awareness of risk spreads and how it triggers a diffusion of coping strategies is prominent in the research agenda of various domains. It requires a deep understanding of how individuals perceive risks and communicate about the effectiveness of protective measures, highlighting learning and social interaction as the core mechanisms driving such processes. Methodological approaches that range from purely physics-based diffusion models to data-driven environmental methods rely on agentbased modeling to accommodate context-dependent learning and social interactions in a diffusion process. Mixing agent-based modeling with data-driven machine learning has become popularity. However, little attention has been paid to the role of intelligent learning in risk appraisal and protective decisions, whether used in an individual or a collective process. The differences between collective learning and individual learning have not been sufficiently explored in diffusion modeling in general and in agent-based models of socioenvironmental systems in particular. To address this research gap, we explored the implications of intelligent learning on the gradient from individual to collective learning, using an agent-based model enhanced by machine learning. Our simulation experiments showed that individual intelligent judgement about risks and the selection of coping strategies by groups with majority votes were outperformed by leader-based groups and even individuals deciding alone. Social interactions appeared essential for both individual learning and group learning. The choice of how to represent social learning in an agent-based model could be driven by existing cultural and social norms prevalent in a modeled society
The impact of social versus individual learning for agents' risk perception during epidemics
© 2018 IEEE. Epidemics have always been a source of concern to people, both at the individual and government level. To fight outbreaks effectively, we need advanced tools that enable us to understand the factors that influence the spread of life-threatening diseases
Consanguinity and reproductive health among Arabs
Consanguineous marriages have been practiced since the early existence of modern humans. Until now consanguinity is widely practiced in several global communities with variable rates depending on religion, culture, and geography. Arab populations have a long tradition of consanguinity due to socio-cultural factors. Many Arab countries display some of the highest rates of consanguineous marriages in the world, and specifically first cousin marriages which may reach 25-30% of all marriages. In some countries like Qatar, Yemen, and UAE, consanguinity rates are increasing in the current generation. Research among Arabs and worldwide has indicated that consanguinity could have an effect on some reproductive health parameters such as postnatal mortality and rates of congenital malformations. The association of consanguinity with other reproductive health parameters, such as fertility and fetal wastage, is controversial. The main impact of consanguinity, however, is an increase in the rate of homozygotes for autosomal recessive genetic disorders. Worldwide, known dominant disorders are more numerous than known recessive disorders. However, data on genetic disorders in Arab populations as extracted from the Catalogue of Transmission Genetics in Arabs (CTGA) database indicate a relative abundance of recessive disorders in the region that is clearly associated with the practice of consanguinity
A systematic review, meta-analysis, and meta-regression of the impact of diurnal intermittent fasting during Ramadan on body weight in healthy subjects aged 16 years and above
PURPOSE: Studies on the effect of Ramadan diurnal intermittent fasting (RDIF) on body weight have yielded conflicting results. Therefore, we conducted a systematic review and meta-analysis to estimate the effect size of body weight changes in healthy, non-athletic Muslims practicing Ramadan fasting, and to assess the effect of covariates such as age, sex, fasting time duration, season, and country, using subgroup analysis, and meta-regression. Covariate adjustments were performed to explain the variability of weight change in response to Ramadan fasting.METHODS: CINAHL, Cochrane, EBSCOhost, EMBASE, Google Scholar, ProQuest Medical, PubMed/MEDLINE, ScienceDirect, Scopus, and Web of Science databases were searched from date of inception in 1950 to the end of August 2019.RESULTS: Eighty-five studies, conducted in 25 countries during 1982-2019, were identified. RDIF yielded a significant, but small reduction in body weight (K = 85, number of subjects, N = 4176 (aged 16-80 years), Hedges' g =- 0.360, 95% confidence interval (CI) - 0.405 to - 0.315, I2 = 45.6%), this effect size translates into difference in means of - 1.022 kg (95% CI - 1.164 kg to - 0.880 kg). Regression analysis for moderator covariates revealed that fasting time (min/day) is a significant (P < 0.05) moderator for weight change at the end of Ramadan, while age and sex are not. Variable effects for the season and country were found.CONCLUSION: RDIF may confer a significant small reduction in body weight in non-athletic healthy people aged 16 years and above, directly associated with fasting time and variably correlated with the season, and country.</p
Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study
PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.
PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
Efficacy of Quasi Agro Binding Fibre on the Hybrid Composite Used in Advance Application
The choice for natural fibre obtained from agricultural products is on the rise
due to its solution to eco-friendly, environmental and improved mechanical
properties concerns. Its abundant availability, low cost, emission reduction and
adaptability to base material for composite make it a prime material for
selection. This review explores diverse perspectives to the future trend of agro
fibre in terms of the thermo-mechanical properties as it applies to advanced
application in building structures. It is important to investigate the
ecofriendliness of the products of composites from fibres in agricultural
wastes so as to achieve a green and sustainable environment. This will come
to fore by the combined efforts of both researchers and feedback from
building stakeholders
