chemical reagents
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2022 ◽  
Vol 147 ◽  
pp. 112622
Author(s):  
Xiao Li ◽  
Xinyuan Sun ◽  
Xuemin Guo ◽  
Xueren Li ◽  
Shouchun Peng ◽  
...  

Author(s):  
Giacomo Cardinali

The examination of unknown sources reveals that by the end of the fifteenth and the beginning of the sixteenth century, there was a widespread awareness in Italy of the damage produced by the passing of time on books and manuscripts. The expression used to describe such cases was lettere svanite or caduche , which indicated that the writing had faded and was almost unreadable, and, as such, hard to transcribe, indicating that the manuscript needed to be preserved from further damage. Already between 1550 and 1552, in Rome and Venice, some ecclesiastics of the Roman Curia attempted to brighten ancient writing, using vegetable distillate high in tannin. In two cases, it is possible to identify manuscripts processed with this method and to determine the preservation formula as well as an accurate description of each step of the method. The process, now brought back to light, anticipates the chemical experimentations by the Benedictines of St Maur and other techniques, widespread in the eighteenth century, and their basic chemical principle, namely the application of tannin. However, the earlier technique is paradoxically much more complicated than the one applied two centuries later.


2021 ◽  
Vol 1 (12) ◽  
pp. 1-62
Author(s):  
Yiglet Mebrat

A Laboratory Manual for the Preparation of Chemical Reagents, Solutions and Special Indicators. ETHIOPIAN BIODIVERSITY INSTITUTE, Microbial Biodiversity Directorate. This manual includes detailed view of the following: Laboratory Safety Precautions, Chemical Reagent Preparation, Buffer and Chemical Solution Preparation, Staining Solution Preparation, Indicators and Dye Solution Preparation, Preparation of Special Reagents, Known and Suspected List of Carcinogens and References.


Horticulturae ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 27
Author(s):  
Meili Xiao ◽  
Huadong Wang ◽  
Xiaonan Li ◽  
Annaliese S. Mason ◽  
Donghui Fu

Rapeseed (Brassica napus) is one of the most important oil crops worldwide. However, an intriguing new use for rapeseed has recently developed: as an ornamental. Tourism based on blossoming fields of these yellow flowers has become a new economic growth opportunity in China. From a breeding perspective, two main problems currently limit the potential of rapeseed as an ornamental. First, the flowering period is quite short (30 days on average), which limits economic income; second, the flower color in commercial cultivars is currently limited to bright yellow, which may pall quickly for sightseers. This review summarizes the possible problems of using rapeseed as an ornamental, and details factors affecting the flowering period, how the flowering period can be prolonged by integrating optimal cultivation measures or/and spraying with chemical reagents, and ways of creating and breeding rapeseed with diverse flower colors.


INDIAN DRUGS ◽  
2021 ◽  
Vol 58 (11) ◽  
pp. 38-41
Author(s):  
Jyoti ◽  
Yogesh Murti ◽  
Krishn K. Agrawal ◽  

Piper nigrum is belongs to the family Piperaceae. The aim of the present study was to extract, isolate and investigate in vitro urolithiatic activity of alkaloid (piperine) from black pepper and identification by chemical reagents. In vitro urolithiatic evaluation of piperine was performed by percentage dissolution and turbidity methods. Calcium oxalate crystals were synthetically prepared and packed in a semipermeable membrane in both methods. Results were compared statistically and it showed significant P​


2021 ◽  
pp. 47-64
Author(s):  
Karina Il'darovna Shaykhiyeva ◽  
Sergey Vladimirovich Fridland ◽  
Svetlana Vasil'yevna Sverguzova

Was reported literature findings of domestic and foreign articles about using of biomass components (leaves, straw, pods, seeds) and wastes of beans (Phaseolus vulgaris) and peas (Pisum sativum) pods shells processing as sorption material for pollutants (metals ions, colorants) removing from water environments. Concise literature findings about Pisum sativum and Phaseolus vulgaris plant structure, cultivation value, and chemical composition of some biomass components are described. Was revealed that composition of beans and peas pods has big amount of proteins, that can provide removing of metals ions such as (Cd(II), Co(II), Cr(III) и Cr(VI), Cu(II), Fe(III), Mo(VI), Ni(II), Pb(II), Sb(III) и Sb(V), Zn(II)) from water environments. Was showed  the possibility of sorption characteristics increase for pollutants by Phaseolus vulgaris and Pisum sativum biomass treatment with different chemical reagents. Was revealed that pollutants sorption isotherms of wastes and biomass of considered legumes are described mostly by Langmuir model than by Freundlich model. The kinetic of process mostly match to pseudo-second order model. It is shown that using of seeds and pods shells of legumes is prospectively for removing of heavy metals ions and suspended particles from water. Was proposed to use charcoal, which was gotten by peas pods carbonization for removing of heavy metals ions from water environments. Concluded, that using of legumes pods extracts is more effective for clearing water environments from heavy metals ions.


Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8254
Author(s):  
Dmitry Mardashov ◽  
Victor Duryagin ◽  
Shamil Islamov

Increasing the field development efficiency of fractured reservoirs is a contemporary issue. This paper presents fundamental and exploratory research results in this field using modern high-tech experimental equipment from the “Arctic” Scientific Centre at the Saint Petersburg Mining University. Oil reserves in fractured reservoirs are enormous; however, they are classified as hard-to-recover. The before-mentioned reservoirs require a specific approach when selecting technologies to improve the efficiency of their development. In this paper, as a solution to the problem under discussion, we propose the use of a physicochemical method of developing fractured reservoirs based on the injection of a water shut-off agent to exclude highly permeable water-conducting fractures from the drainage process. This technology makes it possible to effectively include and develop previously undrained reservoir areas by directly controlling their filtration properties with the use of new highly efficient and ecologically safe chemical reagents and process fluids.


Separations ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 235
Author(s):  
Rajmund Michalski ◽  
Paulina Pecyna-Utylska

Due to the increasing environmental awareness of the public, green chemistry has become an important element of environmental protection. In laboratories around the world, millions of analyses of inorganic and organic anions and cations in water and wastewater samples, and solid and gaseous samples are performed daily. Unfortunately, these activities still generate large costs, including environmental costs, which are related to the scale of the studies, the use of toxic chemical reagents, the waste generated, and the energy consumed. The methods used so far for inorganic ion analysis, including classical methods, are increasingly being replaced by instrumental methods, primarily based on ion chromatography. This paper presents the most important advantages and limitations of ion chromatography, and compares them with the costs of classical analyses for the analytes and sample types. Both the financial and environmental costs associated with the determination of common inorganic ions, such as Cl−, NO2−, NO3−, and NH4+, in 1000 environmental samples, were compared using selected reference wet classical methods and ion chromatography. The advantages and limitations of ion chromatography that allow this separation technique to be classified as a green analytical chemistry method have been described herein.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jie Sun ◽  
Xiaoran Roger Liu ◽  
Shuang Li ◽  
Peng He ◽  
Weikai Li ◽  
...  

AbstractMass spectrometry-based footprinting can probe higher order structure of soluble proteins in their native states and serve as a complement to high-resolution approaches. Traditional footprinting approaches, however, are hampered for integral membrane proteins because their transmembrane regions are not accessible to solvent, and they contain hydrophobic residues that are generally unreactive with most chemical reagents. To address this limitation, we bond photocatalytic titanium dioxide (TiO2) nanoparticles to a lipid bilayer. Upon laser irradiation, the nanoparticles produce local concentrations of radicals that penetrate the lipid layer, which is made permeable by a simultaneous laser-initiated Paternò–Büchi reaction. This approach achieves footprinting for integral membrane proteins in liposomes, helps locate both ligand-binding residues in a transporter and ligand-induced conformational changes, and reveals structural aspects of proteins at the flexible unbound state. Overall, this approach proves effective in intramembrane footprinting and forges a connection between material science and biology.


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