X-ray crystal analysis of the substrates of aconitase. II. Anhydrous citric acid

1960 ◽  
Vol 13 (5) ◽  
pp. 418-426 ◽  
Author(s):  
C. E. Nordman ◽  
A. S. Weldon ◽  
A. L. Patterson
Keyword(s):  
Citric Acid ◽  
X Ray

scholarly journals Two-Step Separation of Chitin from Shrimp Shells Using Citric Acid and Deep Eutectic Solvents with the Assistance of Microwave

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 409 ◽  
Author(s):  
Dandan Zhao ◽  
Wen-Can Huang ◽  
Na Guo ◽  
Shuye Zhang ◽  
Changhu Xue ◽  
...  
Keyword(s):  
Citric Acid ◽  
Deep Eutectic Solvents ◽  
Second Step ◽  
X Ray Diffraction ◽  
X Ray ◽  
Shrimp Shells ◽  
Ft Ir ◽  
Scanning Electron ◽  
Ft Ir Spectroscopy

In this research, a two-step extraction approach was developed for chitin preparation from shrimp shells by utilizing citric acids and deep eutectic solvents (DESs), which effectively removed minerals and proteins. In the first step, minerals of shrimp shells were removed by citric acid, and the demineralization efficiency reached more than 98%. In the second step, the removal of protein was carried out using deep eutectic solvents with the assistance of microwave, and the deproteinization efficiency was more than 88%. The results of scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction analysis (XRD), and thermogravimetric analysis (TGA) showed that the quality of DES-prepared chitin was comparable to that of traditional acid/alkali-prepared chitin. These results were realized without utilizing hazardous chemicals, which are detrimental to the environment. This research indicates that a DES-based preparation approach has the potential for application in the recovery of biopolymers from natural resources.

scholarly journals A new three dimensional proton transfer compound including citric acid and 2,4,6-triamine-1,3,5-triazine: synthesis, characterization and X-ray crystal structure

2010 ◽  
Vol 1 (3) ◽  
pp. 179-181 ◽  
Author(s):  
Hossein Eshtiagh-Hosseini ◽  
Milad Mahjoobizadeh ◽  
Masoud Mirzaei ◽  
Katharina Fromm ◽  
Aurelien Crochet
Keyword(s):  
Crystal Structure ◽  
Citric Acid ◽  
Proton Transfer ◽  
Three Dimensional ◽  
X Ray ◽  
Proton Transfer Compound

Preparation of LiFePO4/C Composite Powders

2011 ◽  
Vol 391-392 ◽  
pp. 377-380
Author(s):  
Guo Jun Li ◽  
Ming Yang ◽  
Hai Li Jing ◽  
Rui Ming Ren
Keyword(s):  
Citric Acid ◽  
Oxalic Acid ◽  
Specific Capacity ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Charge Capacity ◽  
X Ray ◽  
Initial Charge

LiFePO4/C composite powders were prepared by a simple reaction of as-synthesized FePO4•2H2O, LiOH•H2O, oxalic acid and citric acid. The influence of oxalic acid and citric acid in different ratios was investigated on morphology and electrochemical performance of LiFePO4/C composite powders. The characterization of the composites included X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD analysis indicates that the material is well crystallized without impurities. The obtained LiFePO4/C composite powders with well dispersion at CA/OA ratio of 1:1.50 and the initial charge capacity reached 159.3 mAhg-1 at 0.1C rate, meanwhile, the particles prepared at 1:0.75 were close to spherical in shape and the specific capacity value was 149.8 mAhg-1 at 0.1C rate, with a slight decrease on greater C-rates reaching 141.3 mAhg-1 at 1C.

Electro-Less Ni-P Plating Coating of In Situ TiCp/Al-4.5wt.%Cu Vomposites

2015 ◽  
Vol 817 ◽  
pp. 593-598
Author(s):  
Yan Feng Liang ◽  
Sheng Quan Dong ◽  
Gao Hong Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Citric Acid ◽  
Optical Microscopy ◽  
X Ray Diffraction ◽  
Citric Acid Concentration ◽  
X Ray ◽  
In Situ Tic ◽  
Scanning Electron

In situ TiCp/Al-4.5wt.%Cu composites have been coated using an electro-less Ni-P plating technique. The morphology and composition of the plating coating have been examined by scanning electron microscopy, optical microscopy, and X-ray diffraction. The results indicated that the coating had a high-phosphorus amorphous microstructure. The coatings microstructures showed significantly changes when the citric acid concentration in the chemical bath was varied in the range 16-20g/L.

Characterization on Aggregating Structure of Aloe Extract Crosslinked Cotton Fabric

2011 ◽  
Vol 311-313 ◽  
pp. 1132-1135 ◽  
Author(s):  
Yun Hui Xu ◽  
Li Chen
Keyword(s):  
Citric Acid ◽  
Cotton Fabric ◽  
Cotton Textile ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Scanning Electron Microscopic ◽  
Ft Ir ◽  
Textile Products

For exploiting the multifunctional ecological cotton textile products and developing the green modified technology for cotton fabrics, a novel cotton fabric with aloe extract crosslinking was prepared using citric acid as a crosslink agent under the pad-dry-cure procedure. Scanning electron microscopic photographs showed that the modification with aloe extract occurred on the surface of cotton fabric. FT-IR spectra of the modified fabric illuminated that aloe extract crosslinked with cotton fabric through the bridge linkage of citric acid after a series of reaction. The wide angle X-ray diffraction analysis indicated that the crystallinity of aloe extract modified cotton fabric slightly decreased. Furthermore, the changes in the aggregating structure and crystallinity were also reflected in the mechanical property studies of these modified fabrics. After treatment by aloe extract, the breaking strength and elongation of cotton fabric decreased. However, the moisture regain of the modified cotton fabric increased. The results obtained are useful in explaining structure-property correlations with respect to the aggregating structure and crystallinity, and suggest valuable information in planning applications for the aloe extract modified cotton textile products.

Aqueous Ferrofluid of Citric Acid Coated Magnetite Particles

2003 ◽  
Vol 789 ◽  
Author(s):  
A. Goodarzi ◽  
Y. Sahoo ◽  
M. T. Swihart ◽  
P. N. Prasad
Keyword(s):  
Citric Acid ◽  
Photoelectron Spectroscopy ◽  
Quantum Interference ◽  
Fluorescent Dyes ◽  
Aqueous Suspension ◽  
Medical Diagnostics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Magnetite Particles

ABSTRACTMagnetic nanoparticles have found application in medical diagnostics such as magnetic resonance imaging and therapies such as cancer treatment. In these applications, it is imperative to have a biocompatible solvent such as water at optimum pH for possible bio-ingestion. In the present work, a synthetic methodology has been developed to get a well-dispersed and homogeneous aqueous suspension of Fe3O4 nanoparticles in the size range of 8–10 nm. The surface functionalization of the particles is provided by citric acid. The particles have been characterized using transmission electron microscopy, magnetization measurements with a superconducting quantum interference device, FTIR spectroscopy (for surfactant binding sites), thermogravimetric studies (for strength of surfactant binding), and x-ray photoelectron spectroscopy and x-ray diffraction (for composition and phase information). The carboxylate functionality on the surface provides an avenue for further surface modification with fluorescent dyes, hormone linkers etc for possible cell-binding, bioimaging, tracking, and targeting.

scholarly journals Structure-Morphological and Electroconductive Properties of Carbon Materials Based on Saccharose and Citric Acid

2020 ◽  
Vol 21 (3) ◽  
pp. 486-491
Author(s):  
V. I. Mandzyuk ◽  
I. F. Mironyuk ◽  
Yu. O. Kulyk
Keyword(s):  
Citric Acid ◽  
Carbon Materials ◽  
Fractal Structure ◽  
Total Pore Volume ◽  
Specific Electrical Conductivity ◽  
Carbon Precursor ◽  
Significant Development ◽  
X Ray ◽  
X Ray Scattering ◽  
Structure Morphology

The article explores the effect of citric acid as a pore-forming agent on the structure, morphology and electroconductive properties of porous carbon materials (PCMs) obtained from carbon precursor (saccharose) using the methods of small-angle X-ray scattering, low-temperature porometry and impedance spectroscopy. It was found that the volumetric fractal structure is formed in the samples, and the fractal dimension Dv decreases from 2.15 to 1.91 with the addition of citric acid due to surface loosening. It was set that the use of 20 wt.% of citric acid causes the most effective modification of the porous structure of the material, i.e. an increase in specific surface area of 1.35 times, total pore volume of 1.14 times and a significant development of micro- and mesoporosity. It is shown that the use of citric acid as a pore-forming agent leads to an increase in the specific electrical conductivity of PCMs almost 5 times.

scholarly journals The Effect of Citric Acid Concentration on the Properties of LaMnO3 as a Catalyst for Hydrocarbon Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 226 ◽  
Author(s):  
Zakaria Sihaib ◽  
Fabrizio Puleo ◽  
Giuseppe Pantaleo ◽  
Valeria La Parola ◽  
José Luis Valverde ◽  
...  
Keyword(s):  
Citric Acid ◽  
Physicochemical Properties ◽  
Photoelectron Spectroscopy ◽  
Catalytic Performance ◽  
Morphological Properties ◽  
Molar Ratio ◽  
Hydrocarbon Oxidation ◽  
Total Oxidation ◽  
Propene Oxidation ◽  
X Ray

LaMnO3 (LM) catalysts with a molar ratio of citric acid (CA) to metal (La3+ + Mn2+) nitrates ranging from 0.5 to 2 (LM0.5 to LM2) were synthesized by the citrate sol–gel method with the aim of studying the effect of the citric acid ratio on the physicochemical properties and the catalytic performance in hydrocarbon oxidation. Structural and morphological properties of these catalysts were characterized by X-ray diffraction (XRD) and specific surface area (N2 adsorption) measurements, while the chemical composition was determined by inductively coupled plasma atomic emission spectroscopy (ICP-OES). In the selected samples, additional characterizations were carried out by thermogravimetric and differential thermal analysis (TGA/DTA), Fourier Transform Infrared Spectroscopy (FT-IR), temperature-programmed reduction by hydrogen (H2-TPR), and X-ray photoelectron spectroscopy (XPS). The results showed that the amount of citric acid used significantly influenced the TGA/DTA profile of gels along with the physicochemical properties of the catalysts. The XRD patterns are consistent with the perovskite formation as the main phase. The segregation of a small amount of Mn3O4, detected for molar ratios ranging between 0.5 and 1.5, suggested the formation of a slightly nonstoichiometric LaMn1−xO3 phase with a relatively high content of Mn4+. The catalytic performance was evaluated in the total oxidation of two selected hydrocarbons, toluene and propene, which represent typical volatile organic compounds (VOCs). Typically, three consecutive catalytic cycles were performed in order to reach steady-state performance in toluene and propene oxidation. Moreover, the stability of the catalysts under reaction conditions was investigated through 24-h experiments at 17% of toluene conversion. The catalysts LM1.2, LM1.3, and LM1.5 showed the best catalytic performance in both hydrocarbon oxidations, well comparing with the Pd/Al2O3 used as a reference.

Characterization of Mycelium-Like Material Formed During Drying of Salt Stock Prunes

1994 ◽  
Vol 57 (9) ◽  
pp. 817-819
Author(s):  
ROBIN Y.-Y. CHIOU ◽  
WEN-CHING TZENG ◽  
KUO-FONG HUANG
Keyword(s):  
Organic Matter ◽  
Sodium Chloride ◽  
Citric Acid ◽  
Diffraction Analysis ◽  
Diffraction Pattern ◽  
X Ray Diffraction ◽  
X Ray

Material with the appearance of mold mycelium was formed on salt stock prunes during drying. The moisture-free mycelium-like material consisted of 98.5 to 98.7% sodium chloride (NaCl), 1.67% organic matter and 0.165% acidity expressed as citric acid. X-ray diffraction analysis of the material revealed a diffraction pattern similar to that of NaCl. Formation of the material was dependent upon the efficiency and extent of drying. However, the material was not observed on deskinned salt stock prunes subjected to drying.

Antimony-Doped SnO2 Nanoparticles with Controlled Doping Level via Nonaqueous Sol-Gel Procedure

2013 ◽  
Vol 745-746 ◽  
pp. 685-689
Author(s):  
Jun Yan Wu ◽  
Fei Chen ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Citric Acid ◽  
Photoelectron Spectroscopy ◽  
Doping Level ◽  
Sol Gel ◽  
Processing Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Adsorption Desorption ◽  
Controlled Doping

Antimony-doped tin oxide (ATO) nanoparticles with controlled doping level were prepared by a nonaqueous solution route, using alcohol as the solvent, citric acid as an agent, tin (IV) tetrachloride as tin source and antimony (III) chlorideas as antimony sources. As-synthesized samples were characterized by Thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), transmission electron micrographs (TEM), N2 adsorption-desorption isotherms, and X-ray photoelectron spectroscopy (XPS). The results showed that the content of citric acid was the most important processing parameter which was largely governing the reaction course and the complete incorporation of Sb. When the citric acid to metal mol ratio was 2, the particles were the highly crystallized ATO nanoparticles of about 20nm and the Sb atoms were indeed incorporated into the SnO2 crystal structure (cassiterite SnO2).

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