Characterization of Copper–Cobalt Ores and Quantification of Cu2+, Co2+, Co3+, and Fe3+ in Aqueous Leachates Using UV/Visible Spectrophotometry

2016 ◽  
Vol 203 (12) ◽  
pp. 1648-1655 ◽  
Author(s):  
Méschac-Bill Kime ◽  
Dineo Makgoale

2020 ◽  
Vol 8 (2) ◽  
pp. 279
Author(s):  
Azis Akbar Hakim ◽  
I M. Mahaputra Wijaya ◽  
Ida Bagus Wayan Gunam

The purpose of this research is isolation and characterization to find potential bacteria which can produce the most optimal ethanol from the Arak Bali industry in Karangasem Regency, Bali. Bacteria were isolated by exposure method in open air using selective media Zymomonas Sucrose Medium (ZSMA) with the addition of nystatin as much as 0.18 g / L as an antifungal then samples were taken at three different points in one Arak Bali production location, namely the distillation place, the fermentation room for roomie, and the place of taking coconut juice under the coconut tree and the variation of time is 15, 30, and 60 minutes of exposure. Gas checking is done on the bacteria obtained to select its ability to produce ethanol. The results of the scanning of 11 best isolates using UV-visible spectrophotometry were fermented on 500 mL ZSM media for 10 days. BM1-CP14 is the best isolate to produce total ethanol of 15.33 mL through the fermentation process. The results of the characterization of BM1-CP14 isolates were Gram-positive bacteria in the form of bacilli, anaerobic and non-motile bacteria. The results showed that bacteria isolated from open-air also can produce ethanol. Keyword: ethanol, Arak Bali, airborne bacterial exposure, isolation, characterization, UV-Visible spectrophotometry





2012 ◽  
Vol 1371 ◽  
Author(s):  
M.I. Hernández-Castillo ◽  
O. Zaca-Moran ◽  
P. Zaca-Moran ◽  
M. Rojas-López ◽  
V.L. Gayou ◽  
...  

ABSTRACTBy using the citrate reduction procedure we have synthesized Ag nanoparticles, applying several conditions of preparation, being after characterized by UV-visible spectrophotometry. Following a logical sequence, the starting experiment was realized varying the reaction time, after that it was varied the concentration of the reductor agent, and finally it was varied the volume of the reductor agent. According to this methodology, TEM measurements show that firstly we have nanostructures with different shape and size, whereas in the last part of the experiment we have Ag nanoparticles with homogeneous shape and size.



2016 ◽  
Vol 864 ◽  
pp. 154-158
Author(s):  
Mariya Al Qibtiya ◽  
Eka Cahya Prima ◽  
Brian Yuliarto ◽  
Suyatman

Natural dyes extracted from black rice are used as sensitizer for dye sensitized solar cell. The anthocyanin extracted with various pH in acidic and neutral coditions. Preparation of fotolectrode TiO2 film using doctor blade method and resulting average grain size 33,9 nm using X-Ray Diffractometer. Characterization of morphology and cross-section film TiO2 is confirmed by Scanning Electron microscopy (SEM). Optical absorption using UV-Visible Spectroscopy to obtain spectrum absorbance of anthocyanin in various pH. The current-voltage (J-V) characterization shows the performance DSSC have a match relation to the optical absorption. The best absorption of anthocyanin obtained at pH 6 as well as conversion efficiency reaches 2.26% at this pH condition.



Measurement ◽  
2019 ◽  
Vol 135 ◽  
pp. 896-904 ◽  
Author(s):  
Marieta L.C. Passos ◽  
M. Lúcia M.F.S. Saraiva


Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2481
Author(s):  
Anita M. Sutedja ◽  
Emiko Yanase ◽  
Irmanida Batubara ◽  
Dedi Fardiaz ◽  
Hanifah N. Lioe

Although the intake of jack bean (Canavalia ensiformis (L.) DC.), an underutilized tropical legume, can potentially decrease the risk of several chronic diseases, not much effort has been directed at profiling the polyphenolics contained therein. Hence, this work aimed to identify and quantify the dominant jack bean polyphenolics, which are believed to have antioxidant and other bioactivities. Four major compounds were detected and identified as kaempferol glycosides with three or four glycoside units. Their structures were established based on UV-visible, 1D, 2D NMR, and HR-ESI-MS analyses. Specifically, kaempferol 3-O-α-l-rhamnopyranosyl (1→6)- β-d-glucopyranosyl (1→2)-β-d-galactopyranosyl-7-O-[3-O-o-anisoyl]-α-l-rhamnopyranoside was detected for the first time, while the other three compounds have already been described in plants other than jack bean. This new compound was found to have a higher α-glucosidase inhibition activity compared to acarbose.





Author(s):  
S. Louki ◽  
N. Touach ◽  
A. Benzaouak ◽  
V. M. Ortiz-Martínez ◽  
M. J. Salar-García ◽  
...  

This work investigates the photocatalytic activity of new ferroelectric material with formula (Li0.95Cu0.15)Ta0.76Nb0.19O3 (LT76) in a single chamber microbial fuel cell (MFC) and compares its performance with the similar photocatalyst (Li0.95Cu0.15)Ta0.57Nb0.38O3 (LT57). The photocatalysts LT76 and LT57 were synthesized by ceramic route under the same conditions, with the same starting materials. The ratio Ta/Nb was fixed at 4.0 and 1.5 for LT76 and LT57, respectively. These phases were characterized by different techniques including X-ray diffraction (XRD), transmission electronic microscopy (TEM), particle size distribution (PSD), differential scanning calorimetry (DSC), and ultraviolet (UV)–visible (Vis). The new photocatalyst LT76 presents specific surface area of 0.791 m2/g and Curie temperature of 1197 °C. The photocatalytic efficiency of this material is assessed in terms of wastewater treatment and electricity generation by power density and removal rate of chemical oxygen demand (COD) in the presence of a light source. The values of maximum power density and COD removal were 19.77 mW/m3 and 93%, respectively, for LT76.



Author(s):  
A.C. Croce ◽  
G. Bottiroli

Native fluorescence, or autofluorescence (AF), consists in the emission of light in the UV-visible, near-IR spectral range when biological substrates are excited with light at suitable wavelength. This is a well-known phenomenon, and the strict relationship of many endogenous fluorophores with morphofunctional properties of the living systems, influencing their AF emission features, offers an extremely powerful resource for directly monitoring the biological substrate condition. Starting from the last century, the technological progresses in microscopy and spectrofluorometry were convoying attention of the scientific community to this phenomenon. In the future, the interest in the autofluorescence will certainly continue. Current instrumentation and analytical procedures will likely be overcome by the unceasing progress in new devices for AF detection and data interpretation, while a progress is expected in the search and characterization of endogenous fluorophores and their roles as intrinsic biomarkers.



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