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Water

2013

Journal

Articles 1 - 5 of 5

Full-Text Articles in Physical Sciences and Mathematics

Agriculture In A Water Scarce World, Allison Roberts, Amjad Assi, Bassel Daher, Men Li Jun 2013

Agriculture In A Water Scarce World, Allison Roberts, Amjad Assi, Bassel Daher, Men Li

Student Papers in Public Policy

According to the McKinsey report (2009), the world is facing a water scarcity challenge where agriculture is its predominant consumer. It accounts for approximately 3100 billion m3, or 71 percent of global water withdrawals today, and is expected to increase to 4500 billion m3 by 2030. This increase is due to a number of factors: growing population and the ever growing necessity to cater for its food needs, economic growth, the variability of precipitation trends and increase in global temperatures. In addition to the increase in water scarcity, the agricultural sector faces an enormous challenge of producing …

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Short-Term Denitrification In The Metalimnion Of A Eutrophic Reservoir, Aki Kogo, Erin M. Grantz, Thad Scott Jan 2013

Short-Term Denitrification In The Metalimnion Of A Eutrophic Reservoir, Aki Kogo, Erin M. Grantz, Thad Scott

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Denitrification in metalimnetic water was examined under different conditions to determine how addition of nitrate (NO3 -) and particulate carbon (PC), aeration, and concentrations of nitrate affect denitrification. In the first experiment, water samples from a metalimnion were treated with different combinations of NO3 - and PC. Changes in excess N2 -N concentration for 10 days were measured using membrane inlet mass spectrometry (MIMS). The second experiment used the same treatments as the first experiment after aeration of water. Besides excess N2 -N concentrations, O2 concentrations were measured for 16 days. The third experiment examined how different initial concentrations of …

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Environmentally Green Synthesis Of Thioformamide Derivatives, Ali Ramazani, Sang Woo Joo, Fatemeh Zeinali Nasrabadi Jan 2013

Environmentally Green Synthesis Of Thioformamide Derivatives, Ali Ramazani, Sang Woo Joo, Fatemeh Zeinali Nasrabadi

Turkish Journal of Chemistry

Reactions of isocyanides with thioacids in water proceeded smoothly at room temperature and in neutral conditions to afford thioformylamide and thioformamide derivatives in high yields. The reaction proceeded smoothly and cleanly under mild conditions and no side reactions were observed.

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Determination Of Zineb In Tap Water And Tomato Samples By Adsorptive Catalytic Stripping Voltammetry, Özlem Karakoç, Nuri̇ Naki̇boğlu Jan 2013

Determination Of Zineb In Tap Water And Tomato Samples By Adsorptive Catalytic Stripping Voltammetry, Özlem Karakoç, Nuri̇ Naki̇boğlu

Turkish Journal of Chemistry

This paper describes a sensitive and accurate adsorptive catalytic stripping voltammetric method for the determination of zineb (zinc ethylene-bis- dithiocarbamate) in tap water and tomato samples. The method is based on the reduction of adsorbed zineb at a hanging mercury drop electrode following its catalytic oxidation using peroxydisulfate as an oxidizing reagent. Chemical and instrumental parameters of the process were optimized. The catalytic mechanism of the reduction of zineb is discussed as well. The limits of detection (3 s) and quantification (10 s) and linear range of the method for accumulation time of 60 s were calculated as 8.1 nM, …

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Palladium-Edta And Palladium-Edteh_4 Catalyzed Heck Coupling Reactions In Pure Water, Süleyman Gülcemal, Beki̇r Çeti̇nkaya Jan 2013

Palladium-Edta And Palladium-Edteh_4 Catalyzed Heck Coupling Reactions In Pure Water, Süleyman Gülcemal, Beki̇r Çeti̇nkaya

Turkish Journal of Chemistry

Palladium-catalyzed Heck coupling reactions of styrene with bromoarene derivatives are carried out under aerobic conditions in water using water-soluble N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine (EdteH_4) and ethylenediaminetetraacetic acid disodium salt (Na_2EDTA) as ligands. The effect of different bases, catalyst loading, and additives is also monitored. The olefination of bromoarenes with styrene affords the desired products in high yields. The Na_2PdCl_4-Na_2EDTA precatalyst system is also used for the preparative scale (50.0 mmol) synthesis of 4-acetyl-trans-stilbene and 4-styrylbenzaldehyde without a noticeable decrease in the activity. Recycling studies on the Na_2PdCl_4 - Na_2EDTA precatalyst system are also tested in the coupling of 4-bromoacetophenone with styrene.

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