Properties of Cement Brick Containing Expanded Polystyrene Beads (EPS) And Palm Oil Fuel Ash (POFA)

This paper assesses the mechanical properties of cement brick containing Expanded Polystyrene Beads (EPS) and Palm Oil Fuel Ash (POFA) as partial replacement of sand and Ordinary Portland Cement (OPC). The aim of this research are to determine the mechanical properties of brick containing EPS and POFA as partial replacement of sand and OPC. The dosage for EPS replacement is 20%, 30%, 40% and 50% EPS whereas 5%, 10%, 15%, 20% and 25% of POFA replacement. The mechanical properties of the bricks are density, compressive strength and water absorption. The bricks with 30%, 40% and 50% EPS replacement have density below 1680 kg/m3 which considered as lightweight brick. The brick with 50% EPS replacement recorded lowest density which is 1328 kg/m3 while 1629 kg/m3 for the brick with  25% POFA replacement at 56-days of curing. The water absorption testing for these brick are between 7.20%-18.19%. Brick with 0% POFA and 50% EPS replacement has the lowest water absorption properties whereas brick with 25% POFA and 0% EPS replacement has the highest water absorption properties

The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

Moisture absorption effect on thermal, dynamic mechanical and mechanical properties of injection-molded short glass-fiber/polyamide 6,6 composites

Polymer composites of polyamide 6,6 reinforced with short glass fiber were prepared by injection molding, conditioned under dry, 50 relative humidity and wet. Investigations by DSC, DMA and tensile tests were conducted. FLD study showed that more fiber degradation occurred during processing of the composites with higher fiber loading. DSC analysis revealed that the incorporation of glass fiber and moisture into the PA 6,6 matrix resulted in a remarkable decrease in the degree of crystallinity. DMA results revealed the glass transition temperatures were sensitive to moisture absorption and their values moved to a lower temperature upon exposure to moisture. Incorporation of glass fiber into the polyamide 6,6 gave rise to a significant improvement in tensile modulus and tensile strength, while tensile strain was reduced. Exposure to different environments from dry to wet conditions resulted in a decrease in the strength and modulus, while tensile strains decreased

Extrusion and injection-molding of glass fiber/MAPP/polypropylene: Effect of coupling agent on DSC, DMA, and mechanical properties

Glass fiber-reinforced PP composites compatibilized with maleic anhydride grafted polypropylene (MAPP) were compounded with a twin-screw extruder and injection molded. The composite specimens were subjected to DSC, DMA, tensile, and flexural property characterizations. DSC results showed that the presence of glass fiber loading and MAPP produced insignificant effect on the melting temperature of the composites. The melting enthalpy was decreased with glass fiber loadings, but no significant change was noted in the crystalline peak temperatures (Tc). Incorporation of the compatibilizer led to a reduction in Tc. Incorporation of glass fiber reduced the crystalline enthalpy of compatibilized and uncompatibilized systems. DMA results showed that composite properties were affected by the presence of the compatibilizer at low fiber loading (�14 Vf). Tensile and flexural properties also showed sensible improvement of compatibilized against uncompatibilized composite systems

Audience response system (ARS) technology and dentist attendance in smoking cessation workshop

This study assess the effective use of audience response system (ARS), an interactive presenter-audience electronic system, in measuring Malaysian dentists’ interest in attending a less explored non-clinical continuing professional education topic. A total of 157 dentists voluntarily attended a specially designed one-day-four-module workshop conducted in four urban locations. The effective use of ARS in commanding attendance was measured in terms of dentists’ full seminar attendance to completion and opinion regarding the use of the instrument. The retention rate of workshop attendance to completion in the four locations ranged between 76.5 and 100%. Out of these participants, 93.7% said they enjoyed the ARS approach, 92.4% agreed it motivated them to stay on until the end, 97% said it increased their curiosity and appreciates answering in anonymity. The use of ARS technology is effective in enhancing participants’ interest and retention in the workshop, provides interactive learning opportunities and quick feedback and has a potential as an objective instrument in research data collection

Delta-V and ground metric investigations for responsive satellite formation flying

This paper studies a responsive mission involving a dual spacecraft flying formation system. A graphical solution based on the selective dependent variables for acquiring the local and global optimum impulsive velocities is proposed to obtain the minimum orbital transfer velocity changes as well as improving its nadir ground coverage. These studies are conducted using finite thrust of single, dual and three-impulse modes under the condition of unperturbed environment. Based on the obtained results, the relationship between the number of impulses applied and the amount of fuel consumed to retain the leader-follower formation separation is inversely proportional. Whereas, in all cases of the ground metric studies, the formation inclination has shown a dominant influence over other parameters for maximizing the total nadir ground coverage and the swath length. © 2022 IA