Metal concentrations in Sungai Sedili Kecil, Johor, Peninsular Malaysia

Water and sediment from five sampling stations in Sungai Sedili Kecil were sampled in October 2010 and analyzed for 11 metals including cadmium (Cd), copper (Cu), manganese (Mn), iron (Fe), lead (Pb), aluminium (Al), zinc (Zn), nickel (Ni), cobalt (Co), arsenic (As) and argentum (Ar). Results showed that the mean dissolved metal concentrations (in μg/L) in Sungai Sedili waters based on 5 sampling stations (in descending order) for Fe, Al, Zn, Cu, As, Mn, Ni, Pb, Co, Cd and Ag were 443.7, 52.7, 50.2, 34.2, 25.9, 20.3, 6.8, 1.4, 0.77, 0.67 and 0.10 μg/L, respectively. Mean metal concentrations (in μg/g dry weight) for sediments (in descending order) for Fe, Al, Mn, Zn, Pb, Cu, As, Ni, Co, Cd and Ag were 33389.4, 17118.7, 190.5, 55.1, 29.1, 26.3, 19.3, 10.9, 4.7, 0.18 and 0.12 μg/g, respectively. A comparison with various water and sediment quality standards showed that the mean metal concentrations in surface water and sediment of Sungai Sedili Kecil were low and within the range of natural background except for Cu and Fe in water

Analyzing Causes of International Trade Shocks

Purpose: This research aims to analyze the impact of trade shocks on overall international trade relations.   The theoretical framework: of this paper comes from the fact that in recent years, the global economy has witnessed many trade shocks, whether caused by trade disputes between major economies, military disputes, or just crises in the supply of crude oi.   Methodology: The research relied on the analytical descriptive method.   Findings: The research concluded with a set of conclusions, the most prominent of which was that trade shocks do not necessarily result from the requirements of the traditional economic cycle or emergency or exceptional international economic conditions only, but they often occur as a result of economic and trade policies adopted by different countries. The severity of the shock and its time duration depend on the nature of the exported goods. or imported, and the trade shocks, with their positive and negative effects, exceed the state's trade balance to be reflected on all other economic variables such as gross domestic product, income, employment, commodity prices, interest rate, exchange rate, and cash reserves.   Research practical and social implications: The practical and social effects desired from this research are to study the different forms of trade shocks and their economic dimensions over different timescales in a way that makes governments more able to anticipate them and neutralize their negative effects and avoid them, with many of them adopting a policy of trade openness.   Originality/value: The research has great value in light of the risks posed by fluctuations in macro indicators with various trade crises in terms of temporary and permanent shocks or favorable and adverse shocks that are less studied in other previous studies

Synthesis and Antibacterial Activity of some 5,5’-(1,4-phenylene)-bis-1,3,4-Oxadiazole and bis-1,2,4-Triazole Derivatives as Precursors of New S-Nucleosides

Five compounds, namely 5,5’-benzene-1,4-diylbis(1,3,4-oxadiazole-2-thiol)6 and 5,5’-benzene-1,4-diylbis(1H-1,2,4-triazole-3-thiol) 7a and its derivatives 7b–d were synthesized. Two related S-nucleosides 9 and 10 have been prepared from 6 and 7a. Some of these synthesized compounds were tested in vitro by spotting on Mueller Hinton Agar medium against some Gram-positive bacteria, Staphylococcus aureus and Enterococcus faecalis and three Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa, Pseudomonas fluorescens and compared with the known antibiotics cephalosporin (cefotaxim) and gentamycin. Compound 6 showed significant inhibitory activity against Gram-positive E. faecalis and Gram-negative E. coli bacteria while the others have shown variable inhibition activity.Keywords: Terephthalic acid, 1,3,4-oxadiazole, 1H-1,2,4-triazole, S-nucleosides, antimicrobial activit

The Future of the Dollar in Light of the Rising Economic Capacity of Chinese Trade

Purpose: This research deals with the major changes in trade balances between large countries, especially between the United States and China, in light of the continuous increase in the capabilities of the Chinese economy. This was reflected in the exchange value of foreign currencies to reflect this shift in economic balances. The aim of this study is to examine the relations between the rise of the Chinese economy and its currency, the Yuan, and the possible decline in the international dealings of the dollar.   Methodology: The analytical descriptive approach was adopted to analyze the relationship between the increasing capacity of the Chinese economy and the decline in financial transactions in the US dollar.   The theoretical framework: This research will deal with shifts in the economic balance of power by presenting an analysis of the reality of both the United States and China and analyzing the dimensions of this shift on the overall international relations between different countries.   Findings: The results of this research the fact that the volume of trade competition between the United States and China has increased, and despite the importance of sound economic policies that support international competitive advantage, the role of comparative advantage achieved by the abundance of factors of production is no less important than improving the country's commercial performance.   Research practical and social implications: The research is of great importance by showing the size of the relationship between the future of the dollar in commercial dealings with it and the rise of the Chinese economy and the conditions it will impose among all countries dealing in dollars.   Originality/value: The research has great that it analyzes changes in the contemporary international balance of power with the emergence of new international trade powers

Options for Solar Drying Systems: Perspective in Malaysia

Solar drying provides an alternative to the use of fossil fuel. Solar drying system is one of the most promising applications of crop drying. However, there are problems associated with the intermittent natural of solar radiation and the low intensities of solar radiation. The problems can be remedied by the use of heat storage, auxiliary energy source, control system, larger surface collector and hybrid system. However, this will result in a high capital investment. Economic indicators such as cost ofmaintenance, payback period, internal rate of return can be used to calculate the economic of it application.This paper presents the experience in Malaysia on crop drying. We also present the performance of four solar assisted drying systems for crop drying using different collector types, (a) V-groove solar collector with cabinet dryer, (b) double-pass solar collector with porous media in the lower channel and a flat bed drying chamber, (c) Solar dehumidification system and (d) Photovoltaic-thermal solar drying system

Toxicity of Metals to a Freshwater Snail, Melanoides tuberculata

Adult freshwater snails Melanoides tuberculata (Gastropod, Thiaridae) were exposed for a four-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al), and manganese (Mn) concentrations. Mortality was assessed and median lethal times (LT50) and concentrations (LC50) were calculated. LT50 and LC50 increased with the decrease in mean exposure concentrations and times, respectively, for all metals. The LC50 values for the 96-hour exposures to Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.14, 1.49, 3.90, 6.82, 8.46, 8.49, 68.23, and 45.59 mg L−1, respectively. Cu was the most toxic metal to M. tuberculata, followed by Cd, Zn, Pb, Ni, Fe, Mn, and Al (Cu > Cd > Zn > Pb > Ni > Fe > Mn > Al). Metals bioconcentration in M. tuberculata increases with exposure to increasing concentrations and Cu has the highest accumulation (concentration factor) in the soft tissues. A comparison of LC50 values for metals for this species with those for other freshwater gastropods reveals that M. tuberculata is equally sensitive to metals

Synthesis of Novel Thieno[3,2-b]quinolines and Thieno[3,2-d][1,3]thiazoles

New heterocyclic 2-Aryl-9-chloro-5,6,7,8-tetrahydrothieno[3,2-b]quinoline derivatives [Aryl-CTTQ] (2a–e) and 5-arylthieno[3,2-d][1,3]thiazol-2-amine derivatives[Aryl-TZA] (6a–e)were achieved in good yields starting from 5-aryl-3-aminothiophene-2-carboxylic acid (1a–c).Keywords: 5-Aryl-3-aminothiophene-2-carboxylic acid, thieno[3,2-b]quinoline, thiourea, thieno [3,2-d][1,3]thiazol

Microgrid cost optimization: a case study on Abu Dhabi

This paper presents a microgrid cost optimization study specifically focused on the United Arab Emirates (UAE) based on the Genetic and Ant-Bee Colony algorithms. The main objective of the paper is to identify size and amount of power supply sources in Microgrids that result in minimum cost. Specific parameters pertaining to the UAE were employed within the new objective function and constraints. Two different scenarios were tested, and their results have been discussed. During this study, it was evident that solar-PV systems were the second most cost-effective way to reduce cost of microgrids preceded by micro-turbines