Mixture Reactivity Effects on Explosion Venting

Free vented explosions were investigated for 10% methane, 4.2 and 4.5% propane, 6.5 and 7.5% ethylene, 30% and 40% hydrogen in a 10 litre cylindrical explosion vessel for vent coefficients of 4.3 and 21.7. The cylindrical vessel volume was 10L and had a diameter of 162mm and an L/D of 2.8. End ignition was used on the wall opposite the vent. The results are presented against KG and the laminar burning velocity as measures of the mixture reactivity. It is shown that the correlation of the KG effect by Bartknecht does not agree with other experimental data, although the hydrogen results are closer to the present results than the other gases. In contrast the laminar flame venting theory, as used in NFPA68 (2013), does correlate the data well, even though it is not supposed to apply to hydrogen explosions. There was evidence of very fast flames at the vent for hydrogen explosions. Acceleration of the flames towards the vent was demonstrated, due to the expansion of the burnt gases in the direction of the vent. The laminar flame venting theory that is used in NFPA68 (2013) over predicts the measured Pred due to the assumption of the vessel surface area as the area of the flame at Pred. It was shown that the flame arrives at the wall after the flame has vented the vessel and well after the time that Pred occurs. At Kv 4.3 the external overpressure was responsible for Pred, although the difference from Pfv was small for methane, propane and ethylene but for hydrogen the flow through the vent Pfv was the highest overpressure. At Kv = 21.7 the pressure loss due to the unburnt gas flow through the vent was the largest overpressure. For hydrogen sonic flow at the vent occurs and at high Kv sonic flow is predicted to occur using the laminar flame venting equation modified for sonic flow at the vent. Sonic flow at the vent is not taken into account in current venting guidance

Simulation of erosion rate in a reducer for liquid-solid flow system using computational fluid dynamics (CFD)

This research aims to simulate the influences of flow parameters such as particles size, stream velocities, and outlet reducer diameter on the erosion rate for a reducer in light crude oil (C19H30)-solid (sand) flow system. A commercially accessible ANSYS Fluent 2020 R1 (Academic Version)-computational fluid dynamics (CFD) was applied to numerically simulate the erosion rate in the reducer. Three separate models were used in the CFD approach called as a continuous flow modelling, Lagrangian particle tracking, and empirical erosion equation. The simulated parameters covered 100 - 500 μm particles size, 3 - 7 m/s stream velocities and 0.0762 - 0.1778 m outlet reducer diameter. It was found that the maximum erosion rate increased with the increasing size of the particles and stream velocities and decreased with the increasing of the outlet reducer diameter. For all the simulated parameters, the location of maximum erosion rate was found to be at the outlet location of the reducer except for the reducer with the diameter larger than 0.1270 m whereby it is located at the inlet location of reducer

Entropy analysis on convective film flow of power-law fluid with nanoparticles along an inclined plate

Entropy generation in a two-dimensional steady laminar thin film convection flow of a non-Newtonian nanofluid (Ostwald-de-Waele-type power-law fluid with embedded nanoparticles) along an inclined plate is examined theoretically. A revised Buongiorno model is adopted for nanoscale effects, which includes the effects of the Brownian motion and thermophoresis. The nanofluid particle fraction on the boundary is passively rather than actively controlled. A convective boundary condition is employed. The local nonsimilarity method is used to solve the dimensionless nonlinear system of governing equations. Validation with earlier published results is included. A decrease in entropy generation is induced due to fluid friction associated with an increasing value of the rheological power-law index. The Brownian motion of nanoparticles enhances thermal convection via the enhanced transport of heat in microconvection surrounding individual nanoparticles. A higher convective parameter implies more intense convective heating of the plate, which increases the temperature gradient. An increase in the thermophoresis parameter decreases the nanoparticle volume fraction near the wall and increases it further from the wall. Entropy generation is also reduced with enhancement of the thermophoresis effect throughout the boundary layer

Starch-based biofilms for green packaging

The aim of this study is to develop degradable starch-based packaging film with enhanced mechanical properties. A series of low-density polyethylene (LDPE)/tapioca starch compounds with various tapioca starch contents were prepared by twin-screw extrusion with the addition of maleic anhydride-grafted polyethylene as compatibilizer. Palm cooking oil was used as processing aid to ease the blown film process; thus, degradable film can be processed via conventional blown film machine. Studies on their mechanical properties and biodegradation were carried out by tensile test and exposure to fungi environment, respectively. The presence of high starch contents had an adverse effect on the tensile properties of LDPE/tapioca starch blends. However, the addition of compatibilizer to the blends improved the interfacial adhesion between the two materials and hence improved the tensile properties of the films. High content of starch was also found to increase the rate of biodegradability of LDPE/tapioca starch films. It can be proved by exposure of the film to fungi environment. A growth of microbes colony can be seen on the surface of LDPE/tapioca starch film indicates that the granular starch present on the surface of the polymer film is attacked by microorganisms, until most of it is assimilated as a carbon source

Simulation of Erosion Rate in a Reducer for Liquid Solid Flow System using Computational Fluid Dynamics (CFD)

This research aims to simulate the influences of flow parameters such as particles size, stream velocities, and outlet reducer diameter on the erosion rate for a reducer in light crude oil (C19H30)-solid (sand) flow system. A commercially accessible ANSYS Fluent 2020 R1 (Academic Version)-computational fluid dynamics (CFD) was applied to numerically simulate the erosion rate in the reducer. Three separate models were used in the CFD approach called as a continuous flow modelling, Lagrangian particle tracking, and empirical erosion equation. The simulated parameters covered 100 - 500 μm particles size, 3 - 7 m/s stream velocities and 0.0762 - 0.1778 m outlet reducer diameter. It was found that the maximum erosion rate increased with the increasing size of the particles and stream velocities and decreased with the increasing of the outlet reducer diameter. For all the simulated parameters, the location of maximum erosion rate was found to be at the outlet location of the reducer except for the reducer with the diameter larger than 0.1270 m whereby it is located at the inlet location of reducer

Breast Camps for Awareness and Early Diagnosis of Breast Cancer in Countries With Limited Resources: A Multidisciplinary Model From Kenya

Background: Breast cancer is the most common cancer of women in Kenya. There are no national breast cancer early diagnosis programs in Kenya. Objective: The objective was to conduct a pilot breast cancer awareness and diagnosis program at three different types of facilities in Kenya. Methods: This program was conducted at a not-for-profit private hospital, a faith-based public hospital, and a government public referral hospital. Women aged 15 years and older were invited. Demographic, risk factor, knowledge, attitudes, and screening practice data were collected. Breast health information was delivered, and clinical breast examinations (CBEs) were performed. When appropriate, ultrasound imaging, fine-needle aspirate (FNA) diagnoses, core biopsies, and onward referrals were provided. Results: A total of 1,094 women were enrolled in the three breast camps. Of those, 56% knew the symptoms and signs of breast cancer, 44% knew how breast cancer was diagnosed, 37% performed regular breast self-exams, and 7% had a mammogram or breast ultrasound in the past year. Of the 1,094 women enrolled, 246 (23%) had previously noticed a lump in their breast. A total of 157 participants (14%) had abnormal CBEs, of whom 111 had ultrasound exams, 65 had FNAs, and 18 had core biopsies. A total of 14 invasive breast cancers and 1 malignant phyllodes tumor were diagnosed Conclusion: Conducting a multidisciplinary breast camp awareness and early diagnosis program is feasible in different types of health facilities within a low- and middle-income country setting. This can be a model for breast cancer awareness and point-of-care diagnosis in countries with limited resources like Kenya

Educational Psychology Research and Practice (EPRaP): Volume 7, Issue 1

Educational Psychology Research and Practice is an open access periodical published twice a year by the School of Psychology, University of East London. It offers a forum for informed debate and discussion of Educational Psychology research and training as well as a wider focus on issues of social justice and civic engagement in applied psychological practice. EPRaP is open to publishing research findings, literature reviews, commentaries, methodology papers, reflection on practice and book/resource reviews. It is part of a research and learning culture that recognises the importance of knowledge exchange and impact for partners in the community

Long-term outcomes (beyond 5 years) of liver transplant recipients - a transatlantic multicentre study

ABSTRACTThe long-term (>5 year) outcomes following liver transplantation (LT) have not been extensively reported. The aim was to evaluate outcomes of LT recipients who have survived the first 5 years. A multicentre retrospective analysis of prospectively collected data from 3 high volume LT centres (Dallas-USA, Birmingham-UK, and Barcelona-Spain) was undertaken. All adult patients, who underwent LT since the inception of the programme to 31 December 2010, and survived at least 5 years since their LT were included. Patient survival was the primary outcome. A total of 3682 patients who survived at least 5 years following LT (long-term survivors) were included. Overall, median age at LT was 52 years (IQR 44–58); 53.1% were males; and 84.6% were Caucasians. 49.4% (n=1820) died during a follow-up period of 36828 person-years (mean follow-up 10 years). 80.2% (n=1460) of all deaths were premature deaths. Age-standardised all-cause mortality as compared to general population was 3 times higher for males and 5 times higher for females. On adjusted analysis, besides older recipients and older donors, predictors of long-term mortality were malignancy, CVD and dialysis. Implementation of strategies such as non-invasive cancer screening, minimising immunosuppression and intensive primary/secondary cardiovascular prevention could further improve survival