scholarly journals Low molecular weight organic acid salts, markers of old fungi activity in wall paintings

2016 ◽  
Vol 8 (7) ◽  
pp. 1637-1645 ◽  
Author(s):  
Nati Salvadó ◽  
Salvador Butí ◽  
Trinitat Pradell ◽  
Victòria Beltran ◽  
Gianfelice Cinque ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Molecular Weight ◽  
Gas Chromatography Mass Spectrometry ◽  
Low Molecular Weight ◽  
Wall Paintings ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synchrotron Light ◽  
Scanning Electron

Micro-Infrared Spectroscopy (μSR-FTIR) and X-ray diffraction (μSR-XRD) with synchrotron light, Gas Chromatography/Mass Spectrometry (CG/MS), Optical Microscopy (OM) and Scanning Electron Microscopy (SEM/EDS) were used to obtain the distribution of calcium salts of low molecular weight organic acids (LMWOA) in micro-layered micro-samples.

scholarly journals An XRD, SEM and TG study of a uranopilite from Australia

2006 ◽  
Vol 70 (3) ◽  
pp. 299-307 ◽  
Author(s):  
R.L. Frost ◽  
M.L. Weier ◽  
G.A. Ayoko ◽  
W. Martens ◽  
J. Čejka
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Northern Territory ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Evolved Gas ◽  
X Ray ◽  
Temperature Range ◽  
Step Over ◽  
Scanning Electron

AbstractA uranopilite from The South Alligator River, Northern Territory, Australia, has been studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) with EDAX attachment, and thermogravimetry in conjunction with evolved gas mass spectrometry. The XRD shows that the mineral is a pure uranopilite with few if any impurities. The SEM images show that the uranopilite consists of elongated crystals, up to 50μm long and 5 μm wide. Thermogravimetry combined with mass spectrometry shows that dehydration occurs at ∼31°C resulting in the formation of metauranopilite. The first dehydration step over 20–71°C corresponds to a decrease of 5.4 wt.%, equivalent to 6.076 H2O. The second dehydration step, over the temperature range 71 –162.4°C corresponds to a decrease of 4.7 wt.%, equivalent to 5.288 H2O, making a total of 11.364 moles of H2O, close to 12 H2O for uranopilite.Dehydroxylation takes place over the temperature range 80–160°C. The loss of sulphate occurs at higher temperatures in two steps at 622 and 636°C. A mass loss also occurs at 755°C, accounted for by evolved oxygen.

scholarly journals Characterization of the structure and composition of gecko adhesive setae

2005 ◽  
Vol 3 (8) ◽  
pp. 441-451 ◽  
Author(s):  
N.W Rizzo ◽  
K.H Gardner ◽  
D.J Walls ◽  
N.M Keiper-Hrynko ◽  
T.S Ganzke ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Electrophoretic Analysis ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pattern Characteristic ◽  
Additional Protein ◽  
Adhesive Materials

The ability of certain reptiles to adhere to vertical (and hang from horizontal) surfaces has been attributed to the presence of specialized adhesive setae on their feet. Structural and compositional studies of such adhesive setae will contribute significantly towards the design of biomimetic fibrillar adhesive materials. The results of electron microscopy analyses of the structure of such setae are presented, indicating their formation from aggregates of proteinaceous fibrils held together by a matrix and potentially surrounded by a limiting proteinaceous sheath. Microbeam X-ray diffraction analysis has shown conclusively that the only ordered protein constituent in these structures exhibits a diffraction pattern characteristic of β-keratin. Raman microscopy of individual setae, however, clearly shows the presence of additional protein constituents, some of which may be identified as α-keratins. Electrophoretic analysis of solubilized setal proteins supports these conclusions, indicating the presence of a group of low-molecular-weight β-keratins (14–20 kDa), together with α-keratins, and this interpretation is supported by immunological analyses.

scholarly journals Effect of Various Temperatures on Bletillae Rhizoma Polysaccharide Extraction and Physicochemical Properties

2018 ◽  
Vol 9 (1) ◽  
pp. 116 ◽  
Author(s):  
Xiaoyan Long ◽  
Quan Yan ◽  
Linwei Peng ◽  
Xinyue Liu ◽  
Xuegang Luo
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Extraction Temperature ◽  
X Ray Diffraction ◽  
Simple Process ◽  
X Ray ◽  
Gel Permeation ◽  
Scanning Electron

Six fractional polysaccharides were prepared by water extraction and alcohol precipitation under controlled temperature from bletillae rhizoma, a traditional Chinese medicine. Based on this, yields of bletillae rhizome polysaccharides (RBPs) were obtained. The extracting temperature impacted the characteristics of the fractional polysaccharides. The fractional polysaccharides were characterized by glucomannan (GM) content, thermal stability, scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, gel permeation chromatography (GPC), and x-ray diffraction (XRD). For the analysis, 2.0% w/v dispersions of the six fractional polysaccharides were prepared and their flow behaviors were evaluated using a rotational rheometer. The results showed that increased extraction temperature led to increased GM extraction yields and extraction rate, but GM content was relative stable (over 90%). The average molecular weight (Mw) of fractional polysaccharides obtained at 30, 40, 50, 60, 70, and 80 °C was 3.598 × 104, 4.188 × 104, 8.632 × 104, 8.850 × 104, 2.372 × 105, and 3.081 × 105 g/mol, respectively. SEM revealed that fractional polysaccharides had a porous structure of different sizes and densities. Thermal analysis, FTIR, and XRD results indicated that extraction temperature affects the structure and moisture content of fractional polysaccharides. All results showed that the extraction temperature has an obvious impact on the morphology, molecular weight, and polydispersity of the RBPs. This simple process is a promising method for the preparation of fractional polysaccharides.

Electrochemical oxidation of lignin for the production of value-added chemicals on Ni-Co bimetallic electrocatalysts

Holzforschung ◽  
2018 ◽  
Vol 72 (11) ◽  
pp. 951-960 ◽  
Author(s):  
Raziyeh Ghahremani ◽  
John A. Staser
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Scanning Electron Microscopy ◽  
Electrochemical Oxidation ◽  
Degradation Products ◽  
Value Added ◽  
Deposition Process ◽  
Gas Chromatography Mass Spectrometry ◽  
X Ray ◽  
Scanning Electron

AbstractLignin has been submitted to electrochemical oxidation in the presence of nickel (Ni), cobalt (Co) and Ni-Co bimetallic electrocatalysts, which were prepared by a simple electrochemical deposition process. The composition and morphology of the catalyst were studied by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA). The effects of the three electrocatalysts on the electrochemical oxidation of lignin were observed by cyclic voltammetry and chronoamperometry. The degradation products were quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS). The rate of electrochemical oxidation of lignin is higher with Ni-Co bimetallic electrocatalyst with higher Co contents and the main products obtained were vanillin, apocynin and 3-methylbenzaldehyde.

scholarly journals Hydrocracking of Nyamplung Oil (Calophyllum inophyllum 0il) Using CoMo/γ-Al2O3 and CoMo/SiO2 Catalysts

2015 ◽  
Vol 9 (7) ◽  
pp. 43
Author(s):  
Rismawati Rasyid ◽  
Adrianto Prihartantyo ◽  
Mahfud Mahfud ◽  
Achmad Roesyadi
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
Wet Impregnation ◽  
Calophyllum Inophyllum ◽  
X Ray ◽  
Calophyllum Inophyllum Oil ◽  
Wet Impregnation Method ◽  
Scanning Electron

The purpose of this research is to study hydrocracking process of nyamplung oil using 5% and 15% CoMo catalyst and supported on γ-Al2O3 and SiO2. Catalyst was prepared using wet impregnation method and calcined at 500oC for 5 hours without sulfidation process. The X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were performed to analyze the crystalinity and surface morphology. Based on the XRD that MoO2 was deposited on the surface of the catalysts. The hydrocracking of nyamplung (Calophyllum inophyllum) oil was conducted in Parr pressure reactor at 350oC and 3 MP. Hydrocracking product was analyzed by using Gas Cromotography – Mass Spectrometry (GCMS). The highest catalytic activity was obtained by 15% loading CoMo over γ-Al2O3 and the highest yields were 39.58% gasoil, 31.32% gasoline and 7.44% kerosene.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

1992 ◽  
Vol 50 (2) ◽  
pp. 1322-1323
Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Calcium Salts ◽  
Cholesterol Gallstones ◽  
X Ray ◽  
Ca Carbonate ◽  
Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

Photocatalytic activity of TiO2 synthesized by anodization and anodic spark deposition

MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3141-3152
Author(s):  
Alma C. Chávez-Mejía ◽  
Génesis Villegas-Suárez ◽  
Paloma I. Zaragoza-Sánchez ◽  
Rafael Magaña-López ◽  
Julio C. Morales-Mejía ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Surface Characteristics ◽  
Amorphous Solids ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Anodic Spark Oxidation ◽  
Porous Surfaces ◽  
Scanning Electron

AbstractSeveral photocatalysts, based on titanium dioxide, were synthesized by spark anodization techniques and anodic spark oxidation. Photocatalytic activity was determined by methylene blue oxidation and the catalytic activities of the catalysts were evaluated after 70 hours of reaction. Scanning Electron Microscopy and X Ray Diffraction analysis were used to characterize the catalysts. The photocatalyst prepared with a solution of sulfuric acid and 100 V presented the best performance in terms of oxidation of the dye (62%). The electric potential during the synthesis (10 V, low potential; 100 V, high potential) affected the surface characteristics: under low potential, catalyst presented smooth and homogeneous surfaces with spots (high TiO2 concentration) of amorphous solids; under low potential, catalyst presented porous surfaces with crystalline solids homogeneously distributed.

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