ABSTRACT Synthetic acid-base indicators used in titrimetric analysis are highly toxic and harmful to human beings and aquatic organisms. Due to the presence of anthocyanins, some plant extracts have been proved to exhibit solvatochromism properties that can be exploited for use as acid-base indicators in titrimetric analysis. In this research Eichhornia crassipes (E. crassipes) root extract was applied as an acid-base indicator in titrimetric analysis in comparison to standard synthetic acid-...
ABSTRACT The corrosion inhibition efficiency of Adansonia digitata (baobab) pulp and seeds methanolic extracts on mild steel in acidic media is investigated using different standard corrosion methods at room temperature. Weight loss measurement, Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy (EIS) were applied to evaluate inhibition efficiency in the presence of Adansonia digitata Pulp Extract (AdPE) and Adansonia digitata Seed Extract (AdSE) as corrosion inhibitors....
ABSTRACT T h e Oil Palm T r u n k ( O P T ) fib e r w a s p r e t r e a t e d , using T e t r a o x o s ulp h a t e ( vi) a cid H 2 SO 4 , H y d r o c hlo ric a cid H Cl, a n d Trioxonitrate (v) acid HNO 3 , at temperature of 80 o C, and residence time varying from 15 to 45 minutes, and acid concentration between 1 - 2 . 5 % . I t w a s f o u n d t h a t t h e o p tim u m a cid c o n c e n t r a tio n a n d residence time for highest sugar yield, was 1% w/w and 30minutes for the three ac...
ABSTRACT: In this study, the synthesis of crystalline dodecylguanidine free base and its spectroscopic characterization in nonpolar environments are described. IR as well as 1 H and 15N NMR spectra of the free base dissolved in aprotic solvents are substantially different from the previously reported spectra of arginine, or other monoalkylguanidinium compounds, at high hydroxide concentrations. The current results provide improved modelling for the spectroscopic signals that would be expecte...
Abstract Sulphuric acid is a backbone of chemical industry, agriculture and energy sectors. Tanzania has potential sources of producing its own sulphuric acid. The three most common methods: contact process, wet process and lead chamber process of producing sulphuric acid are reviewed. A modified lead chamber method can be a preferred method of producing the mineral acid by using local available raw materials according to Tanzania environment. Among of raw materials, pyrites from Samena area...
ABSTRACT 1-bromo-3-methylbut-1-yn-3-ol, 1-bromo-3-methypent-1-yn-3-ol, 4-hydroxy-4-methyhex-2-yn-nitrile, 1-chloro-3-mrthylpent-1-yn-3-ol, 1-chloro-3-methybut-1-yn-3-ol, 4-methylhex-2-yn-4-ol, 4-methylhexa-2, 3-dienenitrile and 4-methoxy-4-methylhex-2.yn were separately prepared and then each of them was used as the disubstituted acetylene for complexation with copper(I), cyanide, copper(I) bromide and copper(I) chloride respectively in dimethyl form amide (d.m.f) and then in dimethyl sulphid...
ABSTRACT Titanium dioxide or titania (TiO2) being one of the most promising semiconductors for many photoelectrochemical applications, its utilization remains typically confined to ultraviolet (UV) light absorption because of its wide band gap (3.2 eV for anatase and 3.0 eV for rutile), where by UV only accounts for 4-6% of the solar radiation. There is a need to shift the absorption threshold of the UV-region response of TiO2 into the visible region (accounts for ~45% of the total energy of...
Abstract Natural organic matter (NOM) is a generic term for a mixture of organic, slightly watersoluble components found in soil, sediment and natural waters, which represents severe challenges for the process control in water treatment plants as well as water distribution systems. The effective removal of NOM during drinking water treatment requires a good understanding of its character. The current study aimed to identify and quantify NOM present in the Windhoek Goreangab Operating Company...
ABSTRACT Small mammals host diverse communities of both ectoparasites (e.g. fleas and ticks) and endoparasites (e.g. bacteria and viruses). Some parasites are vectors of diseases that infect both humans and wildlife. The main objective of the study was to discover and molecularly characterize novel Hantaviruses and Arenaviruses and to determine the prevalence and intensity of fleas on small mammals in selected areas of Namibia. Small mammals were trapped from six different regions and screen...
ABSTRACT Diospyros lycioides and Euclea divinorum commonly known as muswiti and mutakula respectively in Zambezi region are indigenous to Namibia and belong to the family Ebenaceae. The twigs and roots from these plants are commonly used as chewing sticks in Namibia. If properly used, the chewing sticks have proven to be effective in removing dental plaque due to mechanical cleaning and enhanced salivation. Chewing sticks from other plants have been shown to display antimicrobial activities ...
ABSTRACT Studies on laboratory colonies of Bulinus globosus from forest savannah and transition zones
ABSTRACT The amide alkaloids, steriods and lactones- like constituents
ABSTRACT Tephrosia lupinifolia is used traditionally for the treatment of malaria, diarrhea, toothache and tuberculosis. Two flavonoids, lupinifolin and lupinifolinol were previously isolated from the hexane root extract of T. lupinifolia, but there are no reports on phytochemical and pharmacological studies conducted on the stems and leaves of the plant. The purpose of this study was to prepare and fractionate crude extracts from the leaves and stems of T. lupinifolia, and to evaluate their ...
ABSTRACT Silica sand is a main component in the synthesis of potassium silicates that are commonly used as binding, coating, and adhesives agents. Physical and chemical properties of the sand particles such as grain size, mineralogical and geochemical compositions, determine the viability of sand in the synthesis of potassium silicates. This study analysed sand samples from dunes in the Namib and Kalahari deserts in order to 1) evaluate their suitability in potassium silicate synthesis as wel...
ABSTRACT The freshwater green microalga Parietochloris incisa is the richest known plant source of the polyunsaturated fatty acid (PUFA), arachidonic acid (20:4ω6, AA). Accumulation of AA and docosahexaenoic acid (22:0, DHA) is necessary for brain and retina development in infants. While many microalgae accumulate triacylglycerols (TAG) in the stationary phase or under certain stress conditions, these TAG are generally made of saturated and monounsaturated fatty acids. In contrast, most cell...