UV/visible spectroscopic analysis of CO3+ and CO2+ during the dissolution of cobalt from mixed Co-Cu oxidized ores

2011 ◽  
Vol 18 (3) ◽  
pp. 260-269 ◽  
Author(s):  
J. Ndalamo ◽  
A. F. Mulaba-Bafubiandi ◽  
B. B. Mamba
2015 ◽  
Vol 11 ◽  
pp. 1175-1186 ◽  
Author(s):  
Rym Hassani ◽  
Mahjoub Jabli ◽  
Yakdhane Kacem ◽  
Jérôme Marrot ◽  
Damien Prim ◽  
...  

The present paper describes the synthesis of new palladium–oxazoline complexes in one step with good to high yields (68–95%). The oxazolines were prepared from enantiomerically pure α-aminoalcohols. The structures of the synthesized palladium complexes were confirmed by NMR, FTIR, TOFMS, UV–visible spectroscopic analysis and X–ray diffraction. The optical properties of the complexes were evaluated by the determination of the gap energy values (E g) ranging between 2.34 and 3.21 eV. Their catalytic activities were tested for the degradation of Eriochrome Blue Black B (a model of azo dyes) in the presence of an ecological oxidant (H2O2). The efficiency of the decolorization has been confirmed via UV–visible spectroscopic analysis and the factors affecting the degradation phenomenon have been studied. The removal of the Eriochrome reached high yields. We have found that the complex 9 promoted 84% of color elimination within 5 min (C 0 = 30 mg/L, T = 22 °C, pH 7, H2O2 = 0.5 mL) and the energetic parameters have been also determined.


2007 ◽  
Vol 21 (4) ◽  
pp. 235-243 ◽  
Author(s):  
J. H. Zhou ◽  
X. H. Wu ◽  
C. Yang ◽  
X. T. Gu ◽  
L. Zhou ◽  
...  

Experimental results of UV-visible absorption spectroscopy and fluorescence spectroscopy indicate that hypocrellin A, which has been studied in photodynamic therapy, can interact with the surface of myoglobin through hydrophobic forces, and form a complex. Based on the Stern–Volmer equation, the quenching constants of the process can be calculated to be 4.81×1012L mol−1s−1(t=25°C) and 4.54×1012L mol−1s−1(t=42°C) respectively, and the binding constant is 5.53×104M−1(t=25°C), while the binding sites is 0.94 (t=25°C). In addition, Electron paramagnetic resonance and fluorescence spectroscopic analysis suggests that that the quenching mechanism of the interaction process occurs through the electron transfer between hypocrellin A and myoglobin.


2012 ◽  
Vol 134 (5) ◽  
pp. 2823-2834 ◽  
Author(s):  
Kelly D. Daughtry ◽  
Youli Xiao ◽  
Deborah Stoner-Ma ◽  
Eunsun Cho ◽  
Allen M. Orville ◽  
...  

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Oluwatoyin Adenike Fabiyi

Abstract Nematodes are widespread organisms and pose a serious problem in vegetable production. The use of synthetic nematicides is a common method of bringing down the nematode population to increase crop yield. This has, however, brought about serious pollution to the environment. Leaves and twigs of Terminalia glaucescens were extracted in organic solvents and then chromatographed on a silica gel column. Chromatographic fractions obtained from the methanol and acetone crude extracts were characterized with UV-visible, FTIR, and GCMS and tested for their potential nematode suppressing activity in field micro plots. Spectroscopic analysis of the fractions revealed the presence of compounds such as aldehydes, acids, ketones, phenols, terpenes, hydrocarbons, and fatty acid esters. The extract fractions of T. glaucescens were applied at 100, 75, and 50 mg·ml−1 at 100 ml each and carbofuran at 0.5, 1.0, and 1.5 kg a.i.·ha−1. The vegetative growth of pepper plants as well as the number and weight of fruits increased significantly in plants treated with the above-mentioned extract fractions. The protective role of fractions compared favorably with the synthetic nematicide (carbofuran). The most effective in reduction of the nematode population, and plant growth and yield was the highest concentration of 100 mg·ml−1. Thus, organic solvent extract fractions from T. glaucescens can serve as a biopesticide and an alternative to the environmentally hazardous synthetic nematicide.


2013 ◽  
Vol 25 (21) ◽  
pp. 2994-3000 ◽  
Author(s):  
Keon-Hee Lim ◽  
Kyongjun Kim ◽  
Seonjo Kim ◽  
Si Yun Park ◽  
Hyungjun Kim ◽  
...  

2021 ◽  
Author(s):  
Venkatesh Nakiraboina ◽  
Shyam sunder Goud ◽  
Hari Kumar Nama ◽  
D Ravinder ◽  
Veera Somaiah P

Abstract Sm, doped Mg nano ferrites with composition Mg Sm x Fe2 − x O4 (where X = 0.000, 0.025, 0.050, 0.075,0.1) were synthesized by citrate-gel auto-combustion method. The Samples were analyzed through various experimental techniques. The structural confirmation was done with the basic characterization techniques such as XRD (X-ray Powder Diffraction) and Fourier Transform Infrared (FTIR) spectroscopic analysis. To study the optical absorption behavior of the prepared ferrites, UV-visible spectral analysis was carried out. XRD analysis established the formation of single-phase cubic spinel structure of the materials. FTIR spectra has shown two absorption peaks that are characteristic of spinel nano ferrites. The dc electrical resistivities of the Sm doped Mg nano ferrites were studied by using two probe method at the temperature range of 200–500 °C. A plot of log (σT) vs inverse of temperature yields a curve which reveals a semiconducting nature of prepared nano ferrites. The Thermo Electric Power (TEP) studies of prepared samples carried out at high temperature (573K). The values of the Seebeck coefficient and curie temperature of Sm doped Mg nano ferrites were observed. The magnetization measurements were carried out by using Vibrating Sample Magnetometer (VSM).


2021 ◽  
Vol 9 (1) ◽  
pp. 7-17
Author(s):  
Muhammad Iqbal ◽  
Syed Saeed ul Hassan ◽  
Muhammad Abbas ◽  
Hammad Ahmad

Objective: The key objective of the study is to explore the sensitive, rapid, simple, accurate and economic UV/Vis spectrophotometric method to determine the amount of Amoxicillin trihydrate (AMTR) in bulk pharmaceuticals and in various formulations including dry powder (syrup), tablets and capsules by employing Copper sulphate buffer solution. Methodology: The current spectroscopic analysis performed with 12.5 μg/ml concentration of AMTR at 320 nm follows the Beer’s Lambert Law. The linearity range (10-15µg/ml) and regression data presented a significant correlation coefficient (r2 =0.999). The appropriate level of accuracy, precision, linearity, and mean percentage recovery of AMTR were found adequate relating to the % age error and standard deviations. Results: Amoxicillin trihydrate and its known strengths were scanned and analyzed by our validated method such as; 10.0 µg/ml Amoxicillin (80%), 11.25 µg/ml Amoxicillin (90%), 12.5 µg/ml Amoxicillin (100%), 13.75 µg/ml Amoxicillin (110%) and 15.0 µg/ml Amoxicillin (120%). Conclusions: As the recommended protocol of amoxicillin determination (spectrophotometry) is accurate, precise and statistically evaluated, therefore it could readily be employed for qualitative purposes of either for the raw material and pharmaceutical preparations.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Ch. Nanda Krishna ◽  
Madhavi Katamaneni ◽  
Kalyan Chakravarti Yelavarti ◽  
B. Sobhan Babu ◽  
B. Ravi Kumar ◽  
...  

Wood is a wide flexible material appreciated extremely for its cost-effectiveness, great quantity, and biocompatibility. In addition, naturally existing materials possess prominent biomedical applications, and they can withstand efficiently when compared to other materials like glass, steel, and plastics. The present study revealed the prepared chitosan, silver nanoparticles incorporated with Borassus flabellifer trichome, and fabrication of Prosopis juliflora wood-based biomaterial. A characterization study was done by UV-visible spectroscopic analysis, FTIR analysis, and SEM analysis expressing and confirming a significant characteristic and morphological property of the prepared biomaterial.


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