Physical Methods
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2022 ◽  
Vol 951 (1) ◽  
pp. 012090
P Kemala ◽  
R Idroes ◽  
K Khairan ◽  
T E Tallei ◽  
M Ramli ◽  

Abstract The use of Calotropis gigantea from Ie Seu-Um, Aceh Besar geothermal area for silver nanoparticles (AgNPs) synthesized has been reported. The process of synthesis AgNPs can be carried out with chemical methods, physical methods, and green synthesis methods, but in this study, the process is focused on the green synthesis method using C. gigantea flowers and leaves extract from Ie Seu-Um geothermal area, Aceh Besar. Phytochemical analysis showed that C. gigantea leaves contain alkaloids, steroids, tannins, phenolics, and saponins, while the flowers of C. gigantea contain alkaloids, terpenoids, steroids, flavonoids, tannins, phenolics, and saponins. The reaction of the AgNPs formation was observed by colour change formed. AgNPs-C. gigantea flower extract dan AgNPs-C. gigantea leaves extract showed the reddish-brown and brownish-yellow solution respectively after 48 h incubation in dark condition at room temperature. The result of the reaction characterized using UV-Vis Spectrophotometry showed that the phenomenon of Surface plasmone resonance (SPR) occurs in the mixture of nanoparticles formed. The concentration of AgNO3 as a reagent affected the SPR phenomenon. The result showed that particles formed are the same size and shape.

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 82
Taivo Jõgiaas ◽  
Aivar Tarre ◽  
Hugo Mändar ◽  
Jekaterina Kozlova ◽  
Aile Tamm

Chromium (III) oxide is a technologically interesting material with attractive chemical, catalytic, magnetic and mechanical properties. It can be produced by different chemical and physical methods, for instance, by metal–organic chemical vapor deposition, thermal decomposition of chromium nitrate Cr(NO3)3 or ammonium dichromate (NH4)2Cr2O7, magnetron sputtering and atomic layer deposition. The latter method was used in the current work to deposit Cr2O3 thin films with thicknesses from 28 to 400 nm at deposition temperatures from 330 to 465 °C. The phase composition, crystallite size, hardness and modulus of elasticity were measured. The deposited Cr2O3 thin films had different structures from X-ray amorphous to crystalline α-Cr2O3 (eskolaite) structures. The averaged hardness of the films on SiO2 glass substrate varied from 12 to 22 GPa and the moduli were in the range of 76–180 GPa, as determined by nanoindentation. Lower values included some influence from a softer deposition substrate. The results indicate that Cr2O3 could be a promising material as a mechanically protective thin film applicable, for instance, in micro-electromechanical devices.

2021 ◽  
A.S. Kuznetsov ◽  
Y.Ya. Bikbaeva ◽  
I.A. Kuznetsov ◽  
M.A. Skvortsova ◽  
S.S. Ananiev ◽  

The paper presents the data on the use of percutaneous electrical spinal cord stimulation in patients in the acute period of rehabilitation treatment after ischemic stroke. It was revealed that inclusion of percutaneous electrostimulation of the spinal cord into the rehabilitation program improves the quality of motor skills recovery and can be used in the correction of locomotor functions during rehabilitation after ischemic stroke. Key words: ischemic stroke, percutaneous electrical spinal cord stimulation.

2021 ◽  
Vol 6 (4) ◽  
pp. 51
Luisa Vigorelli ◽  
Elisabetta Croce ◽  
Debora Angelici ◽  
Raffaella Navone ◽  
Sabrina Grassini ◽  

Digital radiography and computed tomography are two fundamental diagnostic techniques in different fields of research, including cultural heritage studies and gemmology. The application of these physical methods of investigation has gained considerable importance as they are non-invasive techniques. The presented work has been mainly focused on micro-tomographic analysis. The project is concerned with the study of natural and cultivated pearls in order to develop an investigation methodology for the analysis, distinction and characterization of different types of pearls, some of them belonging to different precious jewels from private collections. The investigations, carried out on a total of 22 heterogeneous types of pearls, allowed us to establish their origin (natural or cultivated) or to confirm/deny if a hypothesis was already expressed, and as well to highlight the cultivation methodology used case by case. Furthermore, it was possible to ascertain how large and varied the market for cultured pearls is nowadays and how difficult is, in some particular cases, to ascertain their attribution to a certain origin.

A. A. Garanin

The aim of the article is to update the pathophysiological mechanisms that cause the appearance and activation of pathological peristalsis of the esophagus and stomach and associated esophageal-gastrointestinal-diaphragmatic noise, described earlier, designed to expand the diagnostic capabilities of physical methods for diagnosing hiatal hernia and to facilitate the differential diagnosis of this disease with other diseases of the chest. The result of the study is to describe 5 the pathophysiological mechanisms of developing hernia hiatal and lead to the emergence of pathological motility of the esophagus and stomach in the form of the strengthening or emergence of antiperistaltic waves. The resulting acoustic phenomenon is the essence of a new physical symptom in this disease - esophageal-gastrointestinal-diaphragmatic noise. The first mechanism that determines the pathological motor activity of the smooth muscle cells of the esophageal wall is the so-called esophageal “cleansing” peristalsis, which prevents the regurgitation of the acidic contents of the stomach into the esophagus, where the environment is normally neutral. The second mechanism that causes the appearance and strengthening of pathological peristalsis of the stomach is the deformation during the passage of its part through the esophageal opening of the diaphragm into the chest cavity. The third mechanism that determines the occurrence of pathological peristalsis of the esophagus and stomach is a violation of the secretion and metabolism of nitric oxide in diaphragmatic hernias. The fourth mechanism that leads to the appearance of esophageal-diaphragmatic noise is the pathological peristalsis of the esophagus and stomach in patients with hiatal hernia, which causes the appearance of antiperistaltic waves accompanied by gastro-esophageal reflux and manifests itself in clinically pathological belching. The fifth mechanism that causes pathological peristalsis of the esophagus is the phenomenon of hydrodynamic cavitation, which occurs as a result of regurgitation of the contents of the stomach into the esophagus. Understanding the pathophysiological mechanisms that cause the appearance of pathological peristalsis and antiperistalsis of the esophagus and stomach in patients with diaphragmatic hernia allows us to understand the causes of the sound phenomenon and the associated physical symptom in this disease.

2021 ◽  
Indrajit Dutt ◽  
Jagannathrao Allamaraju

Abstract In line with ADNOC Sustainability policy, reduction of GHG emissions, AGP has initiated projects for recovery of CO2 from existing plants. The extracted CO2 is planned to be used for Enhanced Oil Recovery. The current paper highlights method used for evaluation of various location and technology options for implementation of the new CO2 recovery units, considering existing plants flow schemes along with their interfaces and associated challenges. Key Performance Indicators (KPIs) were identified based on Inherent Safety, Economics, Technology Maturity, Product Quality, Operability / Flexibility, Constructability. Identified options were further developed and subsequently evaluated based on preliminary economic analysis and available technical information. Accordingly, weighted scores of the KPIs developed for option selection. Major criteria used for ranking were unit cost of CO2 product, adherence to required H2S and COS specifications, technology maturity and deployment in industry.For one location, the options considered included installation of new Acid Gas Removal Unit (AGRU) upstream of existing AGRU, revamp of existing Acid Gas Enrichment Unit (AGEU), new AGEU, and direct feed of Acid gas to new CO2 recovery unit to supplement falling upstream reservoir profile.For another location, the options included new CO2 recovery plant upstream of existing Sulphur Recovery Unit (SRU) or downstream of existing Tail Gas Treatment Unit (TGTU), compression of TGTU gases upstream of proposed CO2 recovery unit, installation of new unit downstream of existing incinerators, combination of CO2 recovery units of both plants, were also assessed.In addition, new CO2 Dehydration and Compression units considered to meet CO2 product specifications and B/L requirements. Based on project requirements, physical methods of CO2 removal like membranes and molecular sieves deemed unsuitable. Further to discussions with various licensors, emphasis remained on chemical and physical solvent technologies. Based on assessment, solvent swap for AGEU (upstream of existing SRUs) with reduced lean solvent temperature at one location, solvent swap in TGTU followed by a new polishing unit at another location combined with common high pressure compression facility, was selected for engineering development.

Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 551
Dmitriy E. Burmistrov ◽  
Dmitriy Y. Pavkin ◽  
Artyom R. Khakimov ◽  
Dmitry N. Ignatenko ◽  
Evgeniy A. Nikitin ◽  

Sustainable development of the agricultural industry, in particular, the production of milk and feed for farm animals, requires accurate, fast, and non-invasive diagnostic tools. Currently, there is a rapid development of a number of analytical methods and approaches that meet these requirements. Infrared spectrometry in the near and mid-IR range is especially widespread. Progress has been made not only in the physical methods of carrying out measurements, but significant advances have also been achieved in the development of mathematical processing of the received signals. This review is devoted to the comparison of modern methods and devices used to control the quality of milk and feed for farm animals.

О. Kuzmich ◽  
P. Arkushenko ◽  
М. Andrushko ◽  
I. Haidak ◽  
S. Pashchenko

The article highlights the main aspects and features of the algorithm of aviation equipment operation "condition-based" with the use of ground technical means of control and on-board measuring systems and the formation of decision- making principles for further operation of aircraft. To develop methods of technical diagnostics of any technical equipment, it is necessary to identify which parameters characterize its condition and reliability as well as to establish diagnostic criteria and limit values of the controlled parameters. Depending on the nature of the parameters being controlled, there are parametric and physical methods of diagnostics. Based on the results of the diagnostics, we must get a straight answer: whether or not it is necessary to perform repairs or maintenance of the equipment being tested, taking into account the ensuring of failure-free operation before the next diagnostics. Currently, a large number of different measuring equipment that can measure signals that meet the parameters of the object of control and diagnostics are successfully used to objectively determine the technical condition of aircraft. The use of the laboratory for technical diagnostics of aviation equipment in conjunction with on-board measuring systems will provide an opportunity to make a quality technical diagnostics and reasonable conclusion to decide on further operation of the sample of aviation equipment. The use of mentioned laboratory will also predict the occurrence of failures of aviation equipment systems and units. Only a comprehensive approach to the technical diagnostics of aviation equipment with employment of all means of technical control (ground, on-board) will prevent sudden failures of aviation equipment systems.

2021 ◽  
Min-Ah Koo ◽  
HaKyeong Jeong ◽  
Seung Hee Hong ◽  
Gyeung Mi Seon ◽  
Mi Hee Lee ◽  

Abstract Decellularization to produce bioscaffolds composed of the extracellular matrix (ECM) uses enzymatic, chemical, and physical methods to remove antigens and cellular components from tissues. Effective decellularization methods depend on the characteristics of tissues, and in particular, tissues with dense, complex structure and abundant lipid content are difficult to completely decellularize. Our study enables future research on the development of methods and treatments for fabricating bioscaffolds via decellularization of complex and rigid skin tissues, which are not commonly considered for decellularization to date as their structural and functional characteristics could not be preserved after severe decellularization. In this study, decellularization of human dermal tissue was done by a combination of both chemical (0.05% trypsin-EDTA, 2% SDS, 1% Triton X-100) and physical methods (electroporation, sonication). After decellularization, the content of DNA remaining in the tissue was quantitatively confirmed, and the structural change of the tissue and the retention and distribution of ECM components were evaluated through histological and histochemical analysis, respectively. Conditions of the chemical pretreatment that increase the efficiency of physical stimulation as well as decellularization, and conditions for electroporation and sonication without the use of detergents, unlike the methods performed in previous studies, were established to enable the complete decellularization of the skin tissue. The combinatorial decellularization treatment formed micropores in the lipid bilayers of the skin tissues while removing all cell and cellular residues without affecting the ECM properties. Therefore, this procedure can be widely used to fabricate bioscaffolds by decellularizing biological tissues with dense and complex structures.

2021 ◽  
Vol 19 (1) ◽  
Lei Luo ◽  
Zhi Wu ◽  
Yang Wang ◽  
Haiyan Li

AbstractNumerous studies have confirmed the great application potentials of small extracellular vesicles (sEVs) in biological medical field, especially in tissue repair and regeneration. However, the production capability of sEVs by noncancerous cells is very limited, while their dosage requirements in disease treatments are usually very high. Meanwhile, as cell aging, the sEV production capability of cells decreases and the biological function of sEVs changes accordingly. In addition, for special applications, sEVs carrying desired bioactive substances should be designed to perform their expected biological function. Therefore, improving the production of sEVs and precisely regulating their biological function are of great significance for promoting the clinical applications of sEVs. In this review, some of the current classic strategies in affecting the cellular behaviors of donor cells and subsequently regulating the production and biological function of their sEVs are summarized, including gene engineering methods, stress-inducing conditions, chemical regulators, physical methods, and biomaterial stimulations. Through applying these strategies, increased yield of sEVs with required biological function can be obtained for disease treatment and tissue repair, such as bone regeneration, wound healing, nerve function recovery and cancer treatment, which could not only reduce the harvest cost of sEV but promote the practical applications of sEVs in clinic. Graphical Abstract

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