Physical and mechanical properties of Jathropa curcas L. fruits from different planting densities

Jatropha curcas L. is a versatile and rugged crop with enormous unexploited potentials. In order to efficiently take advantage of its full potentials, its physical and mechanical properties need to be well understood. Laboratory tests were conducted to investigate the properties of Jatropha curcas L. fruits obtained from trees of three planting densities namely 10880, 5446 and 3630 plants acre-1. The properties included detachment force, rupture force, deformation at rupture point, deformation ratio at rupture point, hardness, energy used for rupture at both vertical and horizontal loading positions. Other properties studied were 1000 unit mass, dimensions, sphericity, bulk density, solid density, porosity, coefficient of static friction on plywood, steel and stainless steel. The solid density value of 0.97 g cm-3 was obtained which implies that the fruit could float in water for easy cleaning and separation from foreign materials. It was observed that the fruit had the least coefficient of static friction on stainless steel (0.44). The average values obtained for the detachment force and rupture force at vertical orientation were 16.62 N and 57.17 N, respectively. No clear cut trend was observed in the physical and mechanical properties with respect to planting density. However, the mechanical properties were significantly different with respect to the orientation of the fruits. Both the physical and mechanical properties are essential for the design and development of harvesting and processing machines for Jatropha curcas L. fruit

One-way transnational magnetic mass damper model for structural response control against dynamic loadings

Structural responses should be reduced to minimize the consequent structural damage caused by dynamic excitation. The one-way translational magnetic mass damper model is developed as a new type of damper for the purpose of structural response control. The damper utilizes the concept of repulsive force between magnets with same poles to create a magnetic force to stabilize or bring the structure back to its original position. The dynamic performance of the structure was tested using a harmonic shaking table. In this study, the three parameters used are excitation speeds: 2.5V (low), 6.0V (medium) and 8.5V (high); strength of magnets: weak (N35), medium (N45) and strong (N52); and the mass in the damper: 40 g, 101 g and 162 g. The correlations of the parameters towards the structural displacement are verified in the testing. The displacement is highly reduced up to 100% at the first level and 85.2% at the fifth level. The most optimum structural response control was attained when a strong magnetic strength and mass of 162 g are used. When tested with three excitation speeds; 2.5V, 6.0V and 8.5V, the damper with this setting provides the optimum damping effect towards the structure in terms of displacement

Algal oil extraction from microalgae.

This project involves reviewing various oil extraction techniques, and choosing the most economical method for a large-scale application. The techniques reviewed include the press method of oil extraction, hydropyrolysis, ultraviolet-assisted extraction (UAE), microwave-assisted extraction (MAE), conventional solvent extraction and the supercritical carbon dioxide extraction method. Cost analysis is carried out between the three main extraction techniques: pressing method, conventional solvent extraction and supercritical carbon dioxide extraction. Laboratory experiments are also carried out to determine the yield and composition of oil extracted from microalgae, through the solvent extraction method, while the yield and composition of oil extracted using the pressing method and the supercritical carbon dioxide method is obtained from literature review. The most economical method is chosen as the method that generates the most profit, with the lowest investment costs.Bachelor of Engineering (Chemical and Biomolecular Engineering

USING COMPUTER VISION TO IMPROVE CONSTRUCTION SAFETY: A FEASIBILITY STUDY

Bachelor'sBACHELOR OF SCIENCE (PROJECT AND FACILITIES MANAGEMENT

Detection of Sludge Contamination in Crude Palm Oil Using Dielectric Spectroscopy

Degradation and deterioration of crude palm oil (CPO) is a major concern in the palm oil industry because it could affect the quality of palm oil products. The development of rapid and non-destructive measuring techniques is needed to enhance the efficiency of palm oil quality monitoring. This study used dielectric spectroscopy to detect possible sludge contamination in CPO. Dielectric properties of CPO were measured at different temperatures and sludge contamination levels using a liquid dielectric test fixture that was connected to an impedance analyzer with frequencies ranging from 3 to 30 MHz. The variations in dielectric properties were analyzed using ANOVA and Duncan’s multiple range test. Principal component regression (PCR) and partial least squares (PLS) analysis were used for model development to predict sludge contamination. The results showed that there was a significant difference in dielectric constant as the temperature increased from 28°C to 55°C (p 2 values ranging from 0.91 to 0.98. The best result was obtained at 28°C with the lowest value of standard error cross-validation (SECV) of 1.04%. The results showed that dielectric spectroscopy has strong potential for CPO quality monitoring.This article is from Transactions of the ASABE 58 (2015): 227–232, doi:10.13031/trans.58.10656. Posted with permission.</p

Air quality, meteorological variability and pediatric respiratory syncytial virus infections in Singapore

Abstract Respiratory syncytial virus (RSV) is an important cause of respiratory illness among children. While studies have focused on the air-quality and climate dependence of RSV infections, few have been undertaken in South-East Asia where the burden of respiratory illness is among the highest across the globe. This study aimed to determine the relationships between climatic factors and air quality with RSV infections among children in Singapore. We obtained all laboratory-confirmed reports of RSV infections in children below 5 years old from the largest public hospital specializing in pediatric healthcare in Singapore. We assessed the independent cumulative effects of air quality and meteorological factors on RSV infection risk using the Distributed Lag Non-Linear Model (DLNM) framework in negative binomial models adjusted for long-term trend, seasonality and changes in the diagnostic systems. We included 15,715 laboratory-confirmed RSV reports from 2009 to 2019. Daily maximum temperature exhibited a complex, non-linear association with RSV infections. Absolute humidity (Relative Risk, 90th percentile [RR90th percentile]: 1.170, 95% CI: [1.102, 1.242]) was positively associated with RSV risk. Higher levels of particulate matter of aerodynamic diameter of less than (i) 2.5 µm (PM2.5), (ii) 10 µm (PM10), carbon monoxide (CO) and sulfur dioxide (SO2) were associated with lower RSV infection risk. RSV infections exhibited both annual and within-year seasonality. Our findings suggest that falls in ambient temperature and rises in absolute humidity exacerbated pediatric RSV infection risk while increases in air pollutant concentrations were associated with lowered infection risk. These meteorological factors, together with the predictable seasonality of RSV infections, can inform the timing of mitigation measures aimed at reducing transmission

Isotherm kinetics of CR(iii) removal by non-viable cells of acinetobacter haemolyticus

The potential use of non-viable biomass of a Gram negative bacterium i.e. Acinetobacter haemolyticus to remove Cr(III) species from aqueous environment was investigated. Highest Cr(III) removal of 198.80 mg g(-1) was obtained at pH 5, biomass dosage of 15 mg cell dry weight, initial Cr(III) of 100 mg L-1 and 30 min of contact time. The Langmuir and Freundlich models fit the experimental data (R-2 > 0.95) while the kinetic data was best described using the pseudo second-order kinetic model (R-2 > 0.99). Cr(III) was successfully recovered from the bacterial biomass using either 1 M of CH3COOH, HNO3 or H2SO4 with 90% recovery. TEM and FTIR suggested the involvement of amine, carboxyl, hydroxyl and phosphate groups during the biosorption of Cr(III) onto the cell surface of A. haemolyticus. A. haemolyticus was also capable to remove 79.87 mg g(-1) Cr(III) (around 22.75%) from raw leather tanning wastewater. This study demonstrates the potential of using A. haemolyticus as biosorbent to remove Cr(III) from both synthetic and industrial wastewater

Mechanical properties of structural epoxy after sixteen months exposure to outdoor tropical environment

Durability study in regards of epoxy as adhesive which commonly use in current civil industry are still lacking in order to find easy accessible data base. Having validated data to determine its life span will significantly help. The objective of this study is to find out the mechanical properties of Resifix 31 structural epoxy after sixteen (16) months exposure to outdoor tropical environment. The adhesive specimens were cast in a butterfly shaped mould before being exposed to outdoor environment for sixteen (16) months. The exposed specimens were labelled as ESLT-OD16 before being mounted to the Arcan fixture which then attached to the 10kN universal testing machine in tensile mode to determine its shear properties. Microstructure analysis is then performed to study their respective surface fracture and cross-section fracture. The results are then compared to the previous research of control room sample which labelled as ESST-CO06 and sample that exposed to outdoor environment for six (6) months which labelled as ESLT-OD06. The study shows that shear strength and shear modulus of ESLT-OD16 are the lowest when compared to ESST-CO06 which is 61% and 88% respectively. The study also shows that ESLT-OD16 having 34% of weight loss compared to ESLT-OD06 which is resulting from the dry-wet cycle of the unpredictable outdoor condition

Impact of air pollution induced climate change on water availability and ecosystem productivity in the conterminous United States

Abstract Air pollution from greenhouse gases and atmospheric aerosols are the major driving force of climate change that directly alters the terrestrial hydrological cycle and ecosystem functions. However, most current Global Climate Models (GCMs) use prescribed chemical concentrations of limited species; they do not explicitly simulate the time-varying concentrations of trace gases and aerosols and their impacts on climate change. This study investigates the individual and combined impacts of climate change and air pollution on water availability and ecosystem productivity over the conterminous US (CONUS). An ecohydrological model is driven by multiple regional climate scenarios with and without taking into account the impacts of air pollutants on the climate system. The results indicate that regional chemistryclimate feedbacks may largely offset the future warming and wetting trends predicted by GCMs without considering air pollution at the CONUS scale. Consequently, the interactions of air pollution and climate change are expected to significantly reduce water availability by the middle of twenty-first century. On the other hand, the combined impact of climate change and air pollution on ecosystem productivity is less pronounced, but there may still be notable declines in eastern and central regions. The results suggest that air pollution could aggravate Climatic Change (2017) 140:259-272 DOI 10.1007/s10584-016-1850 Electronic supplementary material The online version of this article (doi:10.1007/s10584-016-1850-7) contains supplementary material, which is available to authorized users