41 research outputs found
Performance of Enhanced Polymeric Blend Membranes for the separation of CO2/CH4 mixtures
This study was carried out to evaluate the effect of blending glassy and rubbery polymers with amines in the separation of CO2/CH4 mixtures. The membranes were synthesized by PSU (glassy), PVAc (rubbery) with three different amines using the evaporation method. The theoretical performanceof CO2/CH4 separation was compared against the experimental data for PSU/PVAc (80/20) % wt. membrane with DEA, MDEA and MEA at 2 to 10bar pressure. The experimental results showed that by the incorporation of PVAc and alkanolamines into base PSU, the membranes showed more efficient CO2 separation. The selectivity (CO2/CH4) of PSU/PVAc (80/20) % wt. with DEA membrane was quite high, as compared to PSU/PVAc (80/20) % wt. The amine polymeric blend membrane enhanced the separation of CO2 from CH4 due to adsorption to the amine groups. However, the real selectivity for binary mixtures of CO2/CH4 was lower than the theoretical selectivity
An Atomistic Simulation towards Elucidation of Operating Temperature Effect in CO2 Swelling of Polysulfone Polymeric Membranes
Impact of n-methyl-2-pyrrolidone in monoethanolamine solution to the co2 absorption in packed column: analysis via mathematical modeling
This work investigates the reason behind the change of CO2
absorption behaviour exhibited by monoethanolamine
(MEA) solution via mathematical modeling analysis when physical absorbent, i.e. n-methyl-2-pyrrolidone (NMP), was
added into the solution. The mathematical modeling included the heat model using time resolved numerical method.
Based on the results, it was found that lower CO2
removal performance with the addition of NMP into MEA solution at
pressure of 0.1 MPa was mainly due to the lower temperature rise along the column, which resulted in lower reaction
rate. However, at 3 and 5 MPa pressure conditions, the high physical absorption capability contributed by the presence
of NMP in MEA hybrid solution enhanced the CO2
absorption performance of MEA hybrid solution significantly.
As such, temperature rise of solution was identified as the dominating factor affecting the performance of the hybrid
solvent. The reaction rate of MEA was not affected by the addition of physical solvent. This finding shed crucial insight
on the behaviour MEA-NMP hybrid solution which can be applied during scale-up of the process
Process simulation and optimal design of membrane separation system for CO2 capture from natural gas
A synthesis of evidence for policy from behavioural science during COVID-19
DATA AVAILABILITY : All data and study material are provided either in the Supplementary information or through the two online repositories (OSF and Tableau Public, both accessible via https://psyarxiv.com/58udn). No code was used for analyses in this work.Scientific evidence regularly guides policy decisions, with behavioural science increasingly part of this process. In April 2020, an influential paper proposed 19 policy recommendations (‘claims’) detailing how evidence from behavioural science could contribute to efforts to reduce impacts and end the COVID-19 pandemic. Here we assess 747 pandemic-related research articles that empirically investigated those claims. We report the scale of evidence and whether evidence supports them to indicate applicability for policymaking. Two independent teams, involving 72 reviewers, found evidence for 18 of 19 claims, with both teams finding evidence supporting 16 (89%) of those 18 claims. The strongest evidence supported claims that anticipated culture, polarization and misinformation would be associated with policy effectiveness. Claims suggesting trusted leaders and positive social norms increased adherence to behavioural interventions also had strong empirical support, as did appealing to social consensus or bipartisan agreement. Targeted language in messaging yielded mixed effects and there were no effects for highlighting individual benefits or protecting others. No available evidence existed to assess any distinct differences in effects between using the terms ‘physical distancing’ and ‘social distancing’. Analysis of 463 papers containing data showed generally large samples; 418 involved human participants with a mean of 16,848 (median of 1,699). That statistical power underscored improved suitability of behavioural science research for informing policy decisions. Furthermore, by implementing a standardized approach to evidence selection and synthesis, we amplify broader implications for advancing scientific evidence in policy formulation and prioritization.The National Science Foundation; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Brazilian Federal Agency for the Support and Evaluation of Graduate Education); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Brazilian Federal Agency for the Support and Evaluation of Graduate Education); the Ministry of Science, Technology and Innovation | Conselho Nacional de Desenvolvimento Científico e Tecnológico (National Council for Scientific and Technological Development); National Science Foundation grants; the European Research Council; the Canadian Institutes of Health Research.http://www.nature.com/naturehj2024Gordon Institute of Business Science (GIBS)Non
Fitting multiphasic logistic functions to the lactation curves of Gir x Friesian crossbred dairy cattle in Malaysia
The data used in this study consisted of milk yield (kg) taken at approximately fortnightly intervals from Gir x Friesian crossbred dairy cattle raised at Institut Haiwan Kluang, Malaysia. The data were first edited, smoothed and then fitted with mono-, di- and triphasic logistic functions. In general, parameter estimates for the first lactation were reasonable. However, for the second lactation the estimates were erratic and unreasonable because this was the atypical lactation for which the multiphasic functions were obviously unsuitable. Residual mean squares for the di- and triphasic functions of the first lactation were very similar (0.0002 and 0.0004, respectively) and smaller for the monophasic function (0.0894). For the second lactation, residual mean squares for the triphasic function (0.001) was the lowest compared to those for the mono- and diphasic functions (0.0345 and 0.0315). For the first lactation, the monophasic function did not fit the data well because it had large residuals. The di- and triphasic functions were almost similar in fitting the lactation and had low residuals. For the second lactation, both the mono- and diphasic functions did not fit the data very well and had rather large residuals. The triphasic function was the most fitting and had small residuals. Derived functions were generally lower for the first lactation than the second lactation: initial milk yields (4.88 to 6.0 kg versus 9.9 to 11.8 kg); peak milk yields (5.8 to 9.6 kg versus 12.8 to 15.7 kg) and 305-day milk yields (1147.7 to 1328.6 kg versus 1687.4 to 2296.1 kg)
Fat to fit – an Asian obesity management program and the Malaysian case study
Fat to Fit was a 3-month weight loss program initiated for an Asian obesity management program. The aim of this study is to investigate the effect of physical activity and changes of body size and body composition. A total of 28 subjects ranging from 20-50 years old completed the 3-month program, which required them to follow a structured exercise thrice per week. Subjects were screened and selected through interviews. Anthropometric measurements for body weight, size [height, body dimension circumferences, body mass index (BMI), body composition (fat mass and lean mass)] and skin fold thickness were obtained using conventional method. Body composition was evaluated via Omron HBF 514C body composition monitor and scale. A guided 3-months physical exercise was used as the intervention. Pre- and post- test analysis was computed through paired t-test using IBM SPSS Statistics 22. Changes in body size were examined and the descriptive statistics were reported. Following the intervention, body mass and body composition was significantly lower than the baseline values. This study will be used as a national community intervention programme to combat obesity in Malaysia. This research will contribute to new information on obesity management in Asia Pacific region, which is rather limited at this moment
The role of multi-wall carbon nanotubes in char strength of epoxy based intumescent fire retardant coating
Fire resistance of coatings mostly depends on the formation of char. In this work Multi-wall carbon nanotubes (MWCNTs) were used to improve fire retardant and char properties of the intumescent coating. Different coating formulations were prepared and their heat shielding performance was tested at 950. °C according to ASTM E-119. Char expansion was studied using fire furnace test. Field emission scanning electron microscope was used for char morphology. By means of X-ray Diffraction and Fourier transform infrared spectroscopy the presence of carbon, borophosphate; boron oxide and sassolite in the char was identified. Thermogravimetric analysis results showed that 0.5. wt%MWCNTs enhanced the residual weight of char up to 29.35. wt%. X-ray photoelectron spectroscopy (XPS) confirmed that 0.5. wt% MWCNTs enhanced the carbon content up to 51.90. wt%, lowering oxygen content to approximately 25. wt% in the char that improved the fire resistance performance of the coating. Py rolysis analysis confirmed that 0.5. wt% MWCNTs formulation released less gaseous products and reduced the decomposition of gaseous products. An accelerated weathering test ASTM D 6695-03 also revealed that 0.5. wt% of MWCNTs sustained its reliability up to 90. days in accelerated weathering chamber
High Pressure Rheology and Viscosity of Monoethanolamine with n-Methyl-2-Pyrrolidone and Water Hybrid Solvent
AbstractIn this work, the rheology of a solvent which consisted of monoethanolamine (MEA) as well as water and n-methyl-2-pyrrolidone (NMP) (weight ratio 20:40:40) was studied at gauge pressure up to 5 MPa and temperature range from 303.15 to 333.15 K. The flow chart showed positive linear relationship between shear stress and shear rate for the solvent at all temperature and pressure conditions tested. This trend was consistent with the behaviour of a Newtonian fluid. The dynamic viscosity of MEA-NMP hybrid solvent at temperature from 303.15 to 333.15 K and gauge pressure from (0.1 to 5) MPa was calculated from the rheology data measured