scholarly journals Physico-Chemical Characteristics of Shungite Rock of Kazakhstan

2013 ◽  
Vol 15 (3) ◽  
pp. 241 ◽  
Author(s):  
S.A. Efremov ◽  
S.V. Nechipurenko ◽  
M.K. Kazankapova ◽  
B. Washington ◽  
Kh.S. Tassibekov ◽  
...  

Physico-chemical characteristics of shugite rocks of Kazakhstan (Bakyrchik deposit) were studied using the methods of elementary analysis, IR-spectroscopy, scanning electron microscopy, Raman spectroscopy and X-ray phase analysis. The content of carbon in shungite rock was determined to be from 3% to 19%. The flotation technology for shungite rocks of Kazakhstan was developed, the content of carbon in the concentrate reaching 40.0%. When studying the elemental composition, the mineral part of shungite rocks was stated to be presented, mainly, by silicon, aluminium, calcium, magnesium, potassium, sodium, iron and titanium oxides. IR-spectroscopic investigations showed that in the concentrate, apart from polycyclic hydrocarbons containing methylene groups, there appeared carboxyl groups. The results of scanning electron microscopy (SEM) showed that flotation and thermal activation of shungite rocks on carbon allow obtaining a more developed surface structure and porosity. The structure of shungite carbon was shown by the method of Raman scattering to be close to that of glassy carbon. The results of X-ray diffraction analysis (XRD) of natural shungite rocks showed that the samples under study contained a carbonaceous substance and a number of mineral components: quartz, illite, bassanite, burgerite, muscovite. It is shown that shungite carbon of “Bakyrchik” deposit is identical to shungite of Zazhogino deposit in Russia. The stated physicochemical characteristics allow to determine the directions of the use of carbon concentrate for solution of ecological and technological problems.

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 8641-8652
Author(s):  
Jing Geng ◽  
Lu-Fei Li ◽  
Wen-Liang Wang ◽  
Jian-Min Chang ◽  
Chang-Lei Xia ◽  
...  

Characteristics of the char produced in the co-pyrolysis of used rubber and larch sawdust were studied in the conversion of low-valued pyrolysis char into value-added activated carbon using two-step co-pyrolysis, namely pyrolysis and activation processes. The physicochemical characteristics of the chars were examined by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and scanning electron microscopy (SEM). The results revealed that after the two-step co-pyrolysis, the upgraded carbon had BET surface areas ranging from 600 m2 g−1 to 900 m2 g−1, which were higher than the requirements for activated carbon (American Water Works Association B600 standard). Additionally, as the sawdust/rubber ratio increased, the BET value increased accordingly. A possible reaction mechanism is proposed based on the experimental results during the activation process.


2014 ◽  
Vol 675-677 ◽  
pp. 140-144
Author(s):  
Chun Ying Liu ◽  
Xiao Feng Gong ◽  
Ju Yun Yang

The physico-chemical properties of iron plaques formed on the root surfaces ofCmarex cinerascensunder laboratory conditions were determined using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectrometry (EDS) analysis. Iron plaques were present as an amorphous coating on root surfaces with an uneven distribution. EDS analysis showed that iron plaques were composed of Fe , Si, Al and lesser amounts of Ca in plaqued root surfaces.


1984 ◽  
Vol 32 (11) ◽  
pp. 1154-1158 ◽  
Author(s):  
L Rechardt ◽  
S Lehtinen ◽  
J Wartiovaara

Mouse F9 cells, induced by retinoic acid and dibutyryl cyclic adenosine monophosphate (cAMP) to differentiate into neural-type cells, were incubated for localization of specific acetylcholinesterase (AChE) activity according to the Karnovsky-Roots method where the final enzymatic reaction product is crystalline cupric ferrocyanide and cuprous thiocholine iodide. By scanning electron microscopy (SEM) neural-type cells with long processes were seen. Most of these cells exhibited crystalline precipitates on their surface that in microprobe analysis contained copper, iron, and sulfur. These elements were also detected in some of the neural-type cells that had no visible surface precipitates. Thus, the X-ray analysis also revealed intracellular enzymatic activity. Undifferentiated rounded cells, devoid of AChE activity at the light microscope level, did not show any surface precipitates by SEM and lacked copper, iron, and sulfur emission peaks in the elementary analysis. These results demonstrate that elementary analysis of cytochemical enzymatic reaction products by SEM can be used in identifying cells.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

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.


Author(s):  
M. L. Zimny ◽  
A. C. Haller

During hibernation the ground squirrel is immobile, body temperature reduced and metabolism depressed. Hibernation has been shown to affect dental tissues varying degrees, although not much work has been done in this area. In limited studies, it has been shown that hibernation results in (1) mobilization of bone minerals; (2) deficient dentinogenesis and degeneration of alveolar bone; (3) presence of calculus and tears in the cementum; and (4) aggrevation of caries and pulpal and apical tooth abscesses. The purpose of this investigation was to study the effects of hibernation on dental tissues employing scanning electron microscopy (SEM) and related x-ray analyses.


Author(s):  
Yun Lu ◽  
David C. Joy

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.


Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).


Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt

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.


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