scholarly journals A new synthetic route for the preparation of [Os3(CO)10(μ-OH)(μ-H)] and its reaction with bis(diphenylphosphino)methane (dppm): syntheses and X-ray structures of two isomers of [Os3(CO)8(μ-OH)(μ-H)(μ-dppm)] and [Os3(CO)7(μ3-CO)(μ3-O)(μ-dppm)]

RSC Advances ◽  
2020 ◽  
Vol 10 (73) ◽  
pp. 44699-44711
Author(s):  
Md. Tuhinur R. Joy ◽  
Nikhil C. Bhoumik ◽  
Shishir Ghosh ◽  
Michael G. Richmond ◽  
Shariff E. Kabir
Keyword(s):  
Synthetic Route ◽  
X Ray ◽  
Hydrolysis Of

The cluster [Os3(CO)10(μ-OH)(μ-H)] was obtained in 75% from the hydrolysis of [Os3(CO)10(NCMe)2].

Identification of acid-insoluble filter-plugging compounds and optimal acid-washing procedures for tubular backpulse pressure filters

TAPPI Journal ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 17-23
Author(s):  
KEVIN TAYLOR ◽  
RICH ADDERLY ◽  
GAVIN BAXTER
Keyword(s):  
Calcium Sulfate ◽  
Membrane Filter ◽  
Sulfamic Acid ◽  
Xrd Analysis ◽  
Metal Sulfides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gypsum Formation ◽  
Acid Washing ◽  
Hydrolysis Of

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.

Investigation of the products of carbothermal reduction of yttrium oxide by the hydrolysis method

1984 ◽  
Vol 49 (4) ◽  
pp. 936-943 ◽  
Author(s):  
Bohumil Hájek ◽  
Pavel Karen ◽  
Vlastimil Brožek
Keyword(s):  
Yttrium Oxide ◽  
Carbothermal Reduction ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrolysis Method ◽  
Sample Decomposition ◽  
Products Of Reaction ◽  
Hydrolysis Of ◽  
Lower Carbon

For the investigation of the products of reaction of yttrium oxide with carbon mixed in various proportions, the chemical and X-ray diffraction methods of analysis were combined with the gas chromatographic analysis of the mixture of hydrocarbons and hydrogen formed on the sample decomposition with water. The carboreduction of Y2O3 was examined at relatively low temperatures, convenient for obtaining the reaction intermediates in higher yields. At 1 600 °C and pressures of 10-3 Pa the reduction of a mixture of Y2O3 with carbon in a stoichiometric ratio of 1 : 7 yields YC2 in equilibrium with 20% of Y2OC phase. At lower carbon contents (down to the Y2O3 : C ratio of 1 : 2) tha fraction of the Y2OC phase increases up to approximately 30%. In addition to Y2O3, the reaction mixture contains also Y2C, Y2OC and a phase giving propyne on hydrolysis. The presence of traces of C3 hydrocarbons and small amounts of methane in the product of hydrolysis of the carbide sample prepared by the carbothermal reduction of the oxide can be explained in terms of the occurrence of the Y15C19 phase, probably substituted in part by oxygen, and of the Y2OC phase. The results are compared with those obtained previously for the Sc2O3 + C system.

scholarly journals Multifunctional Biodegradable Vascular PLLA Scaffold with Improved X-ray Opacity, Anti-Inflammation, and Re-Endothelization

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1979
Author(s):  
Ho In Lee ◽  
Yun Heo ◽  
Seung-Woon Baek ◽  
Da-Seul Kim ◽  
Duck Hyun Song ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Inflammatory Responses ◽  
Neointimal Hyperplasia ◽  
Film Surface ◽  
High Mechanical Property ◽  
X Ray ◽  
Stent Restenosis ◽  
X Ray Computed ◽  
Hydrolysis Of

Poly(L-lactic acid) (PLLA) has been used as a biodegradable vascular scaffold (BVS) material due to high mechanical property, biodegradability, and biocompatibility. However, acidic byproducts from hydrolysis of PLLA reduce the pH after the surrounding implanted area and cause inflammatory responses. As a result, severe inflammation, thrombosis, and in-stent restenosis can occur after implantation by using BVS. Additionally, polymers such as PLLA could not find on X-ray computed tomography (CT) because of low radiopacity. To this end, here, we fabricated PLLA films as the surface of BVS and divided PLLA films into two coating layers. At the first layer, PLLA film was coated by 2,3,5-triiodobenzoic acid (TIBA) and magnesium hydroxide (MH) with poly(D,L-lactic acid) (PDLLA) for radiopaque and neutralization of acidic environment, respectively. The second layer of coated PLLA films is composed of polydopamine (PDA) and then cystamine (Cys) for the generation of nitric oxide (NO) release, which is needed for suppression of smooth muscle cells (SMCs) and proliferation of endothelial cells (ECs). The characterization of the film surface was conducted via various analyses. Through the surface modification of PLLA films, they have multifunctional abilities to overcome problems of BVS effectively such as X-ray penetrability, inflammation, thrombosis, and neointimal hyperplasia. These results suggest that the modification of biodegradable PLLA using TIBA, MH, PDA, and Cys will have important potential in implant applications.

scholarly journals Leaching of Chalcopyrite under Bacteria–Mineral Contact/Noncontact Leaching Model

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 230
Author(s):  
Pengcheng Ma ◽  
Hongying Yang ◽  
Zuochun Luan ◽  
Qifei Sun ◽  
Auwalu Ali ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Passivation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Leaching Process ◽  
Copper Leaching ◽  
Hydrolysis Of ◽  
Leaching Efficiency ◽  
Leaching Models ◽  
Scanning Electron

Bacteria–mineral contact and noncontact leaching models coexist in the bioleaching process. In the present paper, dialysis bags were used to study the bioleaching process by separating the bacteria from the mineral, and the reasons for chalcopyrite surface passivation were discussed. The results show that the copper leaching efficiency of the bacteria–mineral contact model was higher than that of the bacteria–mineral noncontact model. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) were used to discover that the leaching process led to the formation of a sulfur film to inhibit the diffusion of reactive ions. In addition, the deposited jarosite on chalcopyrite surface was crystallized by the hydrolysis of the excess Fe3+ ions. The depositions passivated the chalcopyrite leaching process. The crystallized jarosite in the bacteria EPS layer belonged to bacteria–mineral contact leaching system, while that in the sulfur films belonged to the bacteria–mineral noncontact system.

Preparation and structural analysis of (±)-threo-ritalinic acid

2013 ◽  
Vol 69 (11) ◽  
pp. 1225-1228 ◽  
Author(s):  
Sara Wyss ◽  
Irmgard A. Werner ◽  
W. Bernd Schweizer ◽  
Simon M. Ametamey ◽  
Selena Milicevic Sephton
Keyword(s):  
Methyl Ester ◽  
Free Acid ◽  
Nmr Analysis ◽  
Intermolecular Hydrogen Bonds ◽  
X Ray ◽  
X Ray Crystallography ◽  
Ph Values ◽  
Ritalinic Acid ◽  
Methyl Phenidate ◽  
Hydrolysis Of

Hydrolysis of the methyl ester (±)-threo-methyl phenidate afforded the free acid in 40% yield,viz.(±)-threo-ritalinic acid, C13H17NO2. Hydrolysis and subsequent crystallization were accomplished at pH values between 5 and 7 to yield colourless prisms which were analysed by X-ray crystallography. Crystals of (±)-threo-ritalinic acid belong to theP21/nspace group and form intermolecular hydrogen bonds. An antiperiplanar disposition of the H atoms of the (HOOC—)CH—CHpygroup (py is pyridine) was found in both the solid (diffraction analysis) and solution state (NMR analysis). It was also determined that (±)-threo-ritalinic acid conforms to the minimization of negativegauche+–gauche−interactions.

Unprecedented Hexa- and Undecanuclear Frameworks of Two New Tin(IV) Oxo Clusters Resulting from Partial Debenzylation Reactions

2010 ◽  
Vol 65 (11) ◽  
pp. 1293-s1308 ◽  
Author(s):  
Laurent Plasseraud ◽  
Hélène Cattey ◽  
Philippe Richard
Keyword(s):  
Solid State ◽  
1H Nmr Spectroscopy ◽  
Trifluoromethanesulfonic Acid ◽  
Synthetic Route ◽  
State Structure ◽  
X Ray Diffraction ◽  
Neutral Cluster ◽  
Broad Resonance ◽  
X Ray ◽  
The Core

A new and facile synthetic route to the known neutral cluster ((PhCH2)2SnO)6[((PhCH2)2SnOH)2- (CO3)]2 (2) as well as its reactivity toward trifluoromethanesulfonic acid (HO3SCF3, TfOH) are reported. The solid-state structure of the new solvate 2·6C7H8 has been determined by single-crystal X-ray diffraction. The core of 2 can be described as a pair of coplanar pentanuclear [(PhCH2)2SnO]5 ladders bridged at their ends by two carbonate groups. Successive additions of TfOH to a suspension of 2 in CD3CN were monitored by 119Sn{1H} NMR spectroscopy showing the transformation of the fingerprint of 2 (δ = −244, −246, −306 ppm), via new upfield signals, to a final broad resonance located at δ = −474 ppm. Thereafter, two unprecedented ionic monobenzyltin(IV) oxo clusters, 3 and 4, resulting from a debenzylation reaction and exhibiting unusual hexa- and undecanuclear frameworks, respectively, have been isolated as single crystals.

A 35-year-old mystery solved: a facile synthetic route and structural confirmation of tetrachlorobis(diethyl ether)tungsten(IV)

2021 ◽  
Vol 77 (4) ◽  
Author(s):  
Thomas E. Shaw ◽  
Alfred P. Sattelberger ◽  
Titel Jurca
Keyword(s):  
Crystal Structure ◽  
Diethyl Ether ◽  
Thermal Instability ◽  
Room Temperature ◽  
Surface Characteristics ◽  
Hirshfeld Surface ◽  
Asymmetric Unit ◽  
Synthetic Route ◽  
X Ray ◽  
Elemental Analyses

The true identity of the diethyl ether adduct of tungsten(IV) chloride, WCl4(Et2O) x , has been in doubt since 1985. Initially postulated as the bis-adduct, WCl4(Et2O)2, questions arose when elemental analyses were more in line with a mono-ether adduct, viz. WCl4(Et2O). It was proposed that this was due to the thermal instability of the bis-adduct. Here, we report the room-temperature X-ray crystal structure and Hirshfeld surface characteristics of trans-tetrachloridobis(diethyl ether)tungsten(IV), trans-WCl4(Et2O)2 or trans-[WCl4(C4H10O)2]. The compound crystallizes, with half of the molecule in the asymmetric unit, in the centrosymmetric space group P21/n. The W—O distance is 2.070 (2) Å, while the W—Cl distances are 2.3586 (10) and 2.3554 (10) Å.

47,49Ti NMR in Metals, Inorganics, and Gels

2000 ◽  
Vol 55 (1-2) ◽  
pp. 291-297 ◽  
Author(s):  
T. J. Bastow
Keyword(s):  
Solid State ◽  
Titanium Oxide ◽  
Recent Progress ◽  
Titanium Isopropoxide ◽  
Metallic State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrolysis Of ◽  
C Nmr

Some recent progress in solid state 47,49Ti NMR is described and reviewed. The metallic-state work described covers metals such as hep titanium, TiB2 , a number of intermetallics such as TiAl2 and TiAl3· The inorganic work covers the various titanium oxide based materials including the TiO2 polymorphs, anatase, rutile and brookite. The gel work covers the evolution of crystalline titania from gels formed by hydrolysis of titanium isopropoxide. Some complementary data from 17O and 13C NMR and powder X-ray diffraction is also included.

scholarly journals Expression, purification, crystallization and preliminary X-ray analysis of tannase fromLactobacillus plantarum

2013 ◽  
Vol 69 (4) ◽  
pp. 456-459 ◽  
Author(s):  
Mingbo Wu ◽  
Xiaohong Peng ◽  
Hua Wen ◽  
Qin Wang ◽  
Qianming Chen ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Gallic Acid ◽  
Diffusion Method ◽  
Ester Bond ◽  
Asymmetric Unit ◽  
Data Set ◽  
X Ray ◽  
Vapour Diffusion ◽  
Serine Esterases ◽  
Hydrolysis Of

Tannase catalyses the hydrolysis of the galloyl ester bond of tannins to release gallic acid. It belongs to the serine esterases and has wide applications in the food, feed, beverage, pharmaceutical and chemical industries. The tannase fromLactobacillus plantarumwas cloned, expressed and purified. The protein was crystallized by the sitting-drop vapour-diffusion method with microseeding. The crystals belonged to space groupP1, with unit-cell paramtersa= 46.5,b= 62.8,c= 83.8 Å, α = 70.4, β = 86.0, γ = 79.4°. Although the enzyme exists mainly as a monomer in solution, it forms a dimer in the asymmetric unit of the crystal. The crystals diffracted to beyond 1.60 Å resolution using synchrotron radiation and a complete data set was collected to 1.65 Å resolution.

Improved Enzymatic Depolymerization of Chitosan by Ionic Liquid Pretreatment and the Effect of Oligo-Chitosan on Intestinal Flora In Vitro

2011 ◽  
Vol 391-392 ◽  
pp. 1319-1323
Author(s):  
Cui Zheng ◽  
Lin Li ◽  
Hao Pang ◽  
Zhao Mei Wang ◽  
Na Li
Keyword(s):  
Ionic Liquid ◽  
Hydrogen Bonds ◽  
Molecular Hydrogen ◽  
Intestinal Flora ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrolysis Of ◽  
Positive Effect ◽  
Enzymatic Depolymerization

It still remains challenging for effective hydrolysis of chitosan into chitosan oligomers. In this work, a pretreatment was conducted on chitosan by an ionic liquid 1-butyl-3-methylimidazolium chloride ([C4mim]Cl), aiming at improving enzymatic depolymerization of chitosan. X-ray diffraction analysis indicated that the inter- and intra-molecular hydrogen bonds within chitosan molecules were broken by [C4mim]Cl and the crystalline was destroyed. The oligo-chitosan hydrolyzed from IL-pretreated chitosan, coded as COS-IL, showed a DP of 3~5, in contrast to DP 5~8 with oligo-chitosan obtained from untreated chitosan(coded as COS-UN). COS-IL was more effective than COS-UN in inhibiting intestinal spoilage bacterials growth and it has positive effect on the growth of intestinal probiotic bacterials.

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