Environmental Stewardship for Gold Mining in Tropical Regions

Mining has gained strong popularity in recent years due to the increase in global demand for metals and other industrial raw material derived from the ground. However, information and good governance regarding activities related to mining is still very much lacking especially in underdeveloped and developing countries in the tropics. In Malaysia, the importance of environmental stewardship in mining is a new phenomenon. The new National Mineral Policy 2 calls for compliance with existing standards and guidelines, stresses on progressive and post mining rehabilitation as well as promotes the gathering and dissemination of information, best mining practices, public disclosure and corporate social responsibility. Our preliminary studies however have shown that its implementation may have been hampered by inadequate legal and administrative structures, lack of freedom of information, physical inaccessibility, lack of information and public participation. In this presentation, the above issues and measures to reduce the impact of mining, particularly that of gold on the environment with a special focus on Malaysia is discussed. These measures include alternative gold extraction methods, appropriate tailing dam construction and management, health risk assessment and risk management, compliance with the Cyanide Code and liberalization of access to information, facilitation of access to justice, the strengthening of legal and administrative structures as well as corporate accountability to the public as part of corporate social responsibility

Fatigue Crack Growth Behaviour of Sandwiched Metal Panel of Aluminium and Mild Steel under Constant Amplitude Loading

This study concerned about the sandwiched metal panel on the fatigue crack growth of mild steel and aluminium. The fatigue crack growth consists of 3 layer of metal sheet or panel that bonded together using adhesive of epoxy resin by hand lay-up technique. The 3 layers are consisting of 2 face metal sheets and 1 metal sheet as a core for the sandwiched; sandwiched of aluminium with mild steel panel (SAMSP) and sandwiched of mild steel panel (SMSP). The specimen was cut using Electrical Discharge Machine Wire Cut (EDM-wire cut) to get tensile test specimen based on American Standard Testing Method (ASTM) E8 before tested with speed rate of 3mm/min using Universal Testing Machine Instron 5569A (UTM). The stress strain curve was plotted in order to analyse the yield strength, Ultimate Tensile Strength (UTS) and the Young’s Modulus of the sandwiched. UTS value is used for the fatigue test in the maximum stress applied between 0.50%, 0.60%, 0.70%, 0.80% and 0.90% of UTS. The fatigue test was conducted under ASTM E647 compact tension C(T) standard using Instron 8801 Fatigue Machine with constant frequency of 20Hz and subjected to 1 million cyclic loading to reach failure. The crack growth behaviour of the specimen were discover that indicate the fatigue life, (a-N), fatigue crack growth and failure of the structure by the initial notch. The sandwiched of mild steel panel (SMSP) is compared with the sandwiched of aluminium with mild steel panel (SAMSP) to observe the crack growth behaviour and mechanical properties of the specimen in this study. It can be determined that SAMSP has two times better crack growth behaviour that improve the structure properties compare to the SMSP

DNA Isolation and Optimization of ISSR-PCR Reaction System in Oryza sativa L.

Inter simple sequence repeats (ISSRs) have been utilized widely for molecular markers in analyzing the genetic diversity and phylogenetic and regions in the genome flanked by microsatellite sequences. PCR amplification of these regions using a single primer yields multiple amplification products that can be used as a dominant multilocus marker system for the study of genetic variation in various organisms. For this study provides, DNA isolation, adjusting in six factors (Buffer, MgCl2, dNTPs, ISSR primers, Template DNA and Taq polymerase) at six levels, and optimization of PCR temperature for the ISSR reaction was 60-45 °C, primers screening on indica rice (Oryza sativa). In this research, simple method of DNA isolation by using seedling. The objective of the present investigation was to assess the optimizations and quantification. Has been shown that stalk enhanced the maximum value of genomic. The results show that 100 ISSR primers were examined as well as, 56 ISSR primers was productively amplified. Optimum components for PCR reactions were 5.0 μl of 5X PCR Buffer, 1.5 μl of 25mM MgCl2, 1 μl of 10 mM dNTP, 1 μl of 10 Μm ISSR primers, 2 μl Template DNA, and 0.1 μl of 5 units/ml Taq polymerase. Based on this study, has brought out some information on the relationship between these ISSR primers will be applied further for molecular profiling as well as response evaluation in rice varietie

Energy Absorption at High Strain Rate of Magnesium Alloy AZ31B

This paper presents the efficient energy absorption of magnesium alloy AZ31B with reinforcement carbon nanotubes (CNT) and lead (Pb). The high specific energy absorption demonstrated by CNT compared to metals is one of the criteria to improve the AZ31B performance against ballistic penetration. More ductility by adding Pb in the alloy also plays a vital role to increase the energy absorption capability. Four-cylinder shape AZ31B-based specimens are tested dynamically by using compression Split Hopkinson Pressure Bar (SHPB). The diameter and thickness of the specimen is 18 mm and 12.5 mm respectively. The striking velocity used in this work is 20 m/s. By equation of 1D wave propagation, stress-strain curve is plotted and the area under the curve is equivalent to energy absorption. The highest energy absorption is about 270 kJ with the increment of 47% compared to original AZ31B. This increment is consistent with the higher strain rate experienced by the specimen during the test. The strain rate determined from the study is 1300 per second compared to original AZ31B of 850 per second. The finding of this paper is the presence of CNT and lead could improve the energy absorption performance as the strain rate of the specimen also increased

Synthesis, Characterization and Catalytic Performance of H

The purpose of this work is to study the synthesis, characterization, and catalytic performance of two types of solid heteropoly acid catalysts, namely, silicotungstic acid bulk (STAB) and STA-silica sol-gel (STA-SG) compared with sulfuric acid. From the XPS analyses, there was a significant formation of W-O-Si, W-O-W, and Si-O-Si bonding in STA-SG compared to that in STAB. The main spectra of O1s (90.74%, 531.5 eV) followed by other O1s peak (9.26%, 532.8 eV) were due to the presence of W-O-W and W-O-Si bonds, respectively. The STA-SG catalyst was found to be the more environmentally benign solid acid catalyst for the esterification reaction between oleic acid and glycerol due to its lower toxicity supported by silica via sol-gel technique. In addition, the ease of separation for STA-SG catalyst was attributed to its insoluble state in the product phase. The esterification products were then analysed by FTIR and HPLC. Both the H2SO4 and the STAB gave high conversion of 100% and 98% but at a lower selectivity of GME with 81.6% and 89.9%, respectively. On the contrary, the STA-SG enabled a conversion of 94% but with a significantly higher GME selectivity of 95%, rendering it the more efficient solid acid catalyst

Ultralow Sulfur Diesel and Rapeseed Methyl Ester Fuel Impact on Performance, Emitted Regulated, Unregulated, and Nanoparticle Pollutants

Copyright © 2022 The Authors. The operation of engines using rapeseed methyl ester (RME) and ultralow sulfur diesel (ULSD) was tested for the combustion properties, emitted regulated, unregulated exhaust pollutants, and the size of nanoparticles. The combustion analysis showed higher apparent heat release rate and shorter ignition delay period during RME combustion than during ULSD combustion. The ULSD engine has a combustion chamber maximum pressure relatively higher than that of RME. This study showed that the heat release rate of ULSD is always higher than that of RME while more fuel consumption occurred from the combustion of biodiesel in comparison with diesel. When the engine is running on RME, HC and NOx formation increased at high loads up to 15% and 13%, respectively; meanwhile, CO concentrations reduced by 30.9% for the same conditions. Most of the particulate matter (PM) emitted from a diesel engine has a particle size from 5 to 100 nm, while the particle size from ULSD ranged from 5 to 40 nm. Overloading the engine caused a decrease in the sizes of emitted PM for both fuels. The smoke number for RME was less than that for ULSD by 33.9% at high loads. For high engine load, the cumulative concentration number for the nucleation mode decreased, while it increased for the accumulation mode. Furthermore, measurements of formaldehyde, ethane, methane, acetylene, ethylene, propylene, and isocyanic acid emissions showed the presence of these harmful substances at very low concentrations (8 ppm) for both fuels

Energy absorption AZ31B using quenching in nano fluid

This paper focuses on improving energy absorption through a series of heat treatment and quenching in medium, presence of nanoparticle. The characterisation of the experiment was to determine the suitable combination of composition factors: temperature, soaking time, and the medium that consist of nanoparticle on magnesium alloy surface structure to improve the energy absorption using quenching in nanofluids. The diameter and thickness of the specimen are 6 mm and 10 mm, respectively. All specimens undergo heat treatment based on the temperature of the furnace and the soaking time of the specimen in the furnace, which will be submerged into three medium distilled water, and the addition of a 0.1% wt carbon-nanotube (CNT) and 0.1% wt nano-silica. The addition of CNT and nano-silica shows an increment of 106.68%% and 59.30% for energy absorption, respectively, when compared to the controlled sample. Later microscopy has performed on the specimen to correlate the addition of nanoparticles in the heat treatment and improved energy absorption by EDS analysis on the material composition on the specimen’s surface. Therefore, this paper reveals factors of heat treatment and the presence of CNT and Nano silica effects on enhancing magnesium alloy energy absorption: UTS and yield strength using quenching method

Impact of crack growth behavior on high strength steel and sandwich metal panel using the constant stress ratio, frequency and thickness

The armoured vehicle uses a special solid steel that has a heavy vehicle ratio which causes the performance to decrease after being triggered by high velocity impact bullet on rescue missions thus experiencing the phenomenon of fatigue and unstable crack growth flow. In this study, an investigation on crack growth behaviour was carried out for sandwich metal panel and solid High Strength Steel (HSS) which has high ability in terms of residual life. Meanwhile, sandwiched metal panel contains HSS as face sheets and lightweight material as a solid core. The main objective of this study was to determine the crack growth behaviour on two types of structural material by applied frequency (f=10 Hz), stress ratio (R=0.1), and thickness (10 mm) as a constant parameter. The crack growth experiment used compact tension (CT) specimen as followed the ASTM E647 standard. The benchmark for establishing the crack growth behaviour is the (a-N) graph and the Paris law regime, da/dN against stress intensity in order to determine Paris constant (C and m). Based on the results, the sandwich metal panel is more applicable with the number cycle of N = 23300 with an increase in about 27% compared to solid HSS. It can be concluded that the sandwich metal is most practicable and affordable for using higher level of threat for hard armour vehicle panel

The empirical approach to strengthen coordinated cadastral database accuracy

The coordinated cadastral database in Malaysia is known as National Digital Cadastral Database (NDCDB) with an expected accuracy of ±10cm in rural and ±5cm in urban area. Till date, there are approximately 7.8 million land parcels and 22 million boundary markers in the NDCDB for the whole of Peninsular Malaysia and Federal Territory of Labuan covering total area of 132,183 km2. Since 2010, NDCDB block adjustment has been carried out continuously without giving prime concern to eliminate gross errors in the adjustment's input data. This approach aims to propose a methodology to improve the positional accuracy of the existing NDCDB through utilisation of the current eKadaster application. A comprehensive investigation in the office and field processes has been carried out to prove the efficiency of the methodology introduced. This investigation was focused on the East Coast Rail Link (ECRL) right of way (ROW) survey from Dungun to Besut where displacement of 1 to 6 meters relative to the NDCDB coordinates, as shown in the Land Acquisition (LA) Plan, have been identified. Areas involved are coded as Block T10701, T1100101 and T1100102 which are located in Lubuk Kawah and Pelagat Sub-districts, in the state of Terengganu. Positional accuracy of the NDCDB after adjustment was further verified by comparing the coordinates of randomly picked ground proofing points in the field using Real-Time Kinematic (RTK) observation. This will determine the Root Mean Square Error (RMSE) of the respective NDCDB Block based on actual observations and adjusted coordinate values. With that, it can be concluded that the proposed approach is reasonably practical and capable to improve and strengthen the positional accuracy of existing coordinated cadastral database used in Malaysia