Maria Veronica Purwani
Full Text Available The extraction of Nd(OH3 (neodymium hydroxide concentrate containing Y (yttrium, Sm (samarium and Pr (praseodymium as product of monazite processed has been done. The purpose of this study is to determine the separation of Nd from Y, Pr and Nd Sm in Nd concentrate. The aqueous phase was concentrated Nd (OH3 in HNO3 and extractant while organic phase was Tri Butyl Phosphate (TBP in kerosene. Parameters studied were pH and concentration feed, concentration of TBP in kerosene, extraction time and stirring speed. The result showed that the optimization of separation extraction neodymium from samarium, yttrium and praseodymium in Nd(OH3 concentrated with TBP, obtained the optimum condition of pH = 0.2, concentration of feed 100 g /L, concentration of TBP in kerosene 5%, extraction time 15 minutes and stirring speed 150 rpm. With the conditions, Separation Factor (SF obtained for Nd-Y, Nd-Pr, Nd-Sm are 2.242, 4.811, 4.002 respectively, while D and extraction efficiency of Nd are 0.236 and 19.07%.
Rosnida Wati R
Angka COD merupakan ukuran bagi pencemaran air oleh zat-zat organis yang secara alamiah dapat dioksidasi melalui proses mikrobiologi,dan mengakibatkan berkurangnya oksigen terlarut dalam air. Analisa COD berdasarkan, hampir semua bahan organik dapat dioksidasi menjadi karbondioksida dan air dengan bantuan k2Cr2O7 dalam suasana asam.Dari analisa,kadar COD pada air limbah di PT.SOCI adalah 20 mg/L-38 mg/L.Phosfat adalah salah satu molekul yang ditemukan pada air limbah industri.Pengukuran kad...
Full Text Available This work presents the study of the Bioscouring treatment applied on 50 % of hemp + 50 % of cotton blended materials. The goal of the treatment was the removing of morphological impurities present in cotton and hemp fibers in order to obtain cleaner materials with better properties. For enzymatic treatments different concentrations (1-3 % o.w.f from a commercial product named Beisol PRO (a mixture of enzymes pectinases were used. The reaction media was made of phosfate buffer solution of 0.1 M and pH 8. (sodium phosfate/disodium phosphate, 2 g/L sodium citrate (complexing agent and 0.5 % Denimcol Wash RGN (wetting agent. All the experiments were carried out after a central, rotatable second order compound program with two independent variables: enzyme concentration (concentrations between 1-3 % o.w.f and treatment time (15-55 minutes at 20:1 liquid to fabric ratio and a temperature of 55 0C. The reatment efficiency has been verified by the following analyses: weight loss, hydrophilicity, whiteness degree, yellowness degree, crystallinity, tensile strength, elongation at break, Scanning Electron Microscopy (SEM, spectrophotometric analysis in CIELAB system of the samples dyed with alizarin dye. After all the investigations it was found that the bioscouring procedure of 50 % of hemp + 50 % of cotton blended materials conducted to a proper removal of the morphological impurities without affecting the internal structure of cellulose or any significant degradation of the material.
Selvi, Emine Kılıçkaya; Şahin, Uğur; Şahan, Serkan
This method was developed for the determination of trace amounts of aluminum(III) in dialysis concentrates using atomic absorption spectrometry after coprecipitation with lanthanum phosphate. The analytical parameters that influenced the quantitative coprecipitation of analyte including amount of lanthanum, amount of phosfate, pH and duration time were optimized. The % recoveries of the analyte ion were in the range of 95-105 % with limit of detection (3s) of 0.5 µg l -1 . Preconcentration factor was found as 1000 and Relative Standard Deviation (RSD) % value obtained from model solutions was 2.5% for 0.02 mg L -1 . The accuracy of the method was evaluated with standard reference material (CWW-TMD Waste Water). The method was also applied to most concentrated acidic and basic dialysis concentrates with satisfactory results.
Cyclone desliming previous to flotation is one of the determining factors of the concentration performance of phosfate ores. The physical beneficiation of the phosphoro uraniferous ore of Itataia, carried out in the pilot plant, rejects approximately 10,5% P 2 O 5 and 14% U 3 O 8 contained as ''slimes''. The present investigation was to develop a process to recover the fines through the tecniques of flotation and Seletive Floculation. The low P 2 O 5 content and extremely small size of the ''slimes'', led to a low efficiency in the operation of either flotation. The introduction of a Second disliming step swhed promising results. It is work mentioning that the ore presents siliceous-carbonatic gangue and that the direct flotation of phosphates rejects only the silicate portion. Direct flotation followed by reverse flotation of carbonates led to phosphate concentrates containing 28% P 2 O 5 with recoveries of 60%. The results obtained indicate that the fines treatment may lead to increase of 4,5% in overall recovery without decreasing the grade of the final concentrate. (C.D.G.) [pt
Las poblaciones de Phytophthora infestans presentes en papa en el altiplano Cundiboyacense en 1996 son monomórficas para la enzima glucosa-6-fosfato Isomerasa Populations of Phytophthora infestans present on potato in the Cundinamarca and Boyacá plateau in 1996 are monomorphic for glucose-6-phosphate isomerase
Gualtero Cúellar Elsa Janeth
ólo genotipo. Esta homogeneidad, en lo que se refiere a GPI en la población, permite concluir que en esta zona predomina la reproducción asexual, a través de la cual la variación genética es mínima o no se presenta. Resultados alternativos como la aparición de genotipos nuevos apoyarían la existencia de migraciones de otras poblaciones o la recombinación sexual explicada por la presencia de los tipos de apareamiento A1 y A2.
Potato late blight, a disease caused by the Oomycete Phytophthora infestans, is responsible in great proportion for severe decrements in potato production in the Cundinamarca and Boyacá plateaus. Until now, late blight control has been done mainly with fungicides. The widened genetic variability in populations of this organism for a number of traits, including sensitivity to commercially available fungicides, observed in a world-wide perspective, has shown the need to research the genetic structure of local populations. This study was launched to characterize the populations of P. infestans in Cundinamarca and Boyacá through the polymorphism of glucose-6-phosfate isomerase (GPI. The results pointed at a clonal nature of these populations. All the local isolates were homozygous monomorphic for GPI, with genotype 100/100. Isolate Ro showed genotype 86/100 that corresponds to lineage US-1. Isolate MT2 showed genotype 84/100. These iso lates correspond to heterozygous populations that may have resulted from sexual reproduction. Isolate HIN had genotype 100/100, coinciding with local isolates. This isolate belongs to mating type A1 and corresponds to lineage US-6. This lineage represents one of the earliest migrations from Mexico to the United States, Europe and the rest of the world. Prior to the migrations of mating type A2. Results indicate that local populations are not too diverse, and suggest a clonal orrqtn. These results agree with the evaluation of this same population as regards sensitivity to metalaxil and mating type (Gonzalez, 1997