Introduction With a 20% growth rate in 2001, organic agriculture continues to expand in the U.S. and the world (OTA, 2002). After the release of consistent federal standards for products marketed as “organic” in October 2002 (USDA/AMS, 2002), organic production and consumption was expected to increase beyond current organic sales of $10 billion in 2001 (OTA, 2002). In 1999, Iowa farmers reporte...

A survey of surface, spring and borehole waters associated with the ophiolite rocks of Cyprus shows five broad water types (1) Mg-HCO3, (2) Na-SO4-Cl-HCO3, (3) Na-Ca-Cl-SO4-OH-CO3, (4) Na-Cl-SO4 and (5) Ca-SO4. The waters represent a progression in chemical reactivity from surface waters that evolve within a groundwater setting due to hydrolysis of the basic/ultrabasic rock as modified by CO2-w...

The present investigation deals with limnobiotic status of the Almatti reservoir from February, 2003 to January, 2005. The study revealed that there exists a fluctuations of the physical factors viz., rainfall, humidity, air and water temperature, pH and electrical conductivity (EC), and chemical factors viz., dissolved oxygen (DO), free carbon dioxide, total alkalinity, total hardness, calcium...

Three commercial membranes (NF70, NF90 and TFC-SR) were firstly characterized in terms of pure water flux and the: rejection of uncharged (alcohols and sugars) compounds. Subsequently, the rejection of monovalent (sodium and chloride) and divalent (calcium and sulphate) ions in single (NaC1, CaC12 and Na2SO4) and binary (NaC1/Na2SO4, CaClJCaSO4, NaC1/CaC12 and Na2SO4/CaSO4) salt mixtures was st...

A Plackett-Burman factorial design with 15 experiments was conducted to evaluate the influence of seven factors on lipases production by Fusarium solani. The investigated were peptone, tryptone, yeast extract, calcium chloride, potassium phosphate, magnesium sulfate, and copper sulphate. Five fixed variables (cotton oil, pH, temperature, agitation, time) maintained as a response enzymatic activ...

The present study is concerned with the production of cephalosporin C by Cephalosporium acremonium C-10. Two culture media were tested for the production of antibiotic. Among these culture media M1 containing sucrose, ammonium acetate, cornstarch, sugar cane molasses, soybean meal, calcium carbonate, calcium sulphate and methyl oleate gave optimum production of cephalosporin C. The cultural con...

Silicone rubber (SR) samples are coated with various types of artificially prepared pollutants, in order to identify and distinguish them by employing laser induced breakdown spectroscopy (LIBS). LIBS analysis is successful identifying the elemental composition pollutants. The presence copper sulphate as well carbon-based compounds such fly ash, coal calcium-based cement calcium phosphate (fert...

The impact of cellulose ethers (CE) on C3A hydration was examined to support the understanding of the retarding effect of CE on cement hydration. In this sense, we successively studied the CE adsorption on ettringite and calcium hydroaluminates, and then the CE influence during C3A hydration in presence or absence of calcium sulphate. We emphasized a phase-specific adsorption of CE depending on...

An Ultic Haploxeralf soil collected from ridges built into the slopes of the Coastal Mountain Range of Central Chile was used in applications of humic and fulvic acids (HFA) extracted from sludge from sewage treatment plants, in combination with gypsum (CaSO4). A total of 12 treatments were applied by combining four doses of HFA (0, 20, 30 and 40 t ha-1) with three doses of gypsum (0, 1.2 and 6...

This article focuses on the hydration, and associated microstructure development, of b-hemihydrate to dihydrate (gypsum). The sound velocity is used to quantify the composition of the fresh slurry as well as the hardening and hardened—porous—material. Furthermore, an overview of available hydration kinetic and volumetric models for gypsum is addressed. The presented models predict the sound vel...