In this work, a green, simple and highly efficient procedure for the synthesis of bis(indolyl)methanes is described. The condensation of indoles with carbonyl compounds catalyzed by citric acid in water affords bis(indolyl)methanes in high yields and relatively short reaction times. The advantages of this method are using of water as a low cost solvent and efficient recyclability of the catalyst.

China is a country with severe water shortages. Water is becoming scarcer due to population growth, industrialization and urbanization. Recent studies show that by the next 50 years water resources per capita will go down to around 1700 m 3, which is the threshold of severe water scarcity. Especially in North China, water shortage has become a critical constraint factor for socioeconomic develo...

According to recent technology road maps, system cost reductions and development of standardised plug-and-function systems are some of the most important goals for solar heating technology development. Retrofitting hot water boilers in single-family houses when installing solar collectors has the potential to significantly reduce both material and installation costs. Previous studies have inves...

a water soluble, bronsted acid, 5-sulfosalicylic acid as an efficient organocatalyst was used for the synthesis of physiologically active 2-substituted benzimidazole derivatives from o-phenylenediamine and aromatic aldehydes in ethanol at reflux condition. cost-effectiveness, use of non-hazardous solvents, metal free and commercially available catalyst, single-step, environmentally friendly gre...

To evaluate the effectiveness of the chulli water purifier, a new household water treatment strategy in Bangladesh that relies on passing water through a stove, we interviewed persons who had this water purifier. From households using it regularly, we tested untreated water, sand-filtered water without heat pasteurization, sand-filtered and heat pasteurized water, and household stored, treated ...

Laboratory studies were conducted to compare the relative fitness of clodinafop-propargyl herbicide resistant Lolium rigidum accessions with their clodinafop-propargyl susceptible counterparts in 2014. Factors evaluated were Lolium populations at constant salinity stress (0, 5, 10, 15, 20 and 25 dS cm2) and water stress (0, -3, -6, -9, -12 and -15 bar). The maximum germination in salinity stres...

One of innovate techniques that was used for improvement of water treatment process is application of ultrasound waves. In this study, different applications of ultrasound technology in water treatment process such as membrane filtration, turbidity and total suspended solid reduction, algae removal, disinfection process, water softening process and other pollutants removal such as halomethanes ...

Nanofiltration (NF) membrane can efficiently remove the ions from groundwater, especially for high valence ions. Results show that the removal rate of fluoride was approximately 67% by the NF system, while for arsenic the removal rate was more than 93%. NF presented the well selective removal for fluoride. The quality of product water meets the national drinking water standards. Therefore, the ...

BACKGROUND The burden of illness can be described by addressing both incidence and illness severity attributable to water recreation. Monetized as cost, attributable disease burden estimates can be useful for environmental management decisions. OBJECTIVES We characterize the disease burden attributable to water recreation using data from two cohort studies using a cost of illness (COI) approa...

this paper presents a simplifiedlagrangian multiplier based algorithm to solve the fixed head hydrothermalscheduling problem. in fixed head hydrothermal scheduling problem, waterdischarge rate is modeled as quadratic function of hydropower generation andfuel cost is modeled as quadratic function of thermal power generation. thepower output of each hydro unit varies with the rate of water discha...