scholarly journals Determination of butyric acid dosage based on clinical and experimental studies – a literature review

2020 ◽  
Vol 15 (2) ◽  
pp. 119-125
Author(s):  
Tomasz Banasiewicz ◽  
Dorota Domagalska ◽  
Katarzyna Borycka-Kiciak ◽  
Grażyna Rydzewska
Keyword(s):  
Literature Review ◽  
Butyric Acid ◽  
Experimental Studies ◽  
Acid Dosage

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

Energetic properties of peat saturated with petroleum products

2020 ◽  
Vol 13 (2) ◽  
pp. 105-109
Author(s):  
E. S. Dremicheva
Keyword(s):  
Crude Oil ◽  
Diesel Fuel ◽  
Energy Use ◽  
Experimental Studies ◽  
Calorific Value ◽  
Petroleum Products ◽  
Ash Content ◽  
Motor Oil ◽  
Initial Sample

This paper presents a method of sorption using peat for elimination of emergency spills of crude oil and petroleum products and the possibility of energy use of oil-saturated peat. The results of assessment of the sorbent capacity of peat are presented, with waste motor oil and diesel fuel chosen as petroleum products. Natural peat has been found to possess sorption properties in relation to petroleum products. The sorbent capacity of peat can be observed from the first minutes of contact with motor oil and diesel fuel, and significantly depends on their viscosity. For the evaluation of thermal properties of peat saturated with petroleum products, experimental studies have been conducted on determination of moisture and ash content of as-fired fuel. It is shown that adsorbed oil increases the moisture and ash content of peat in comparison with the initial sample. Therefore, when intended for energy use, peat saturated with petroleum products is to be subjected to additional drying. Simulation of net calorific value has been performed based on the calorific values of peat and petroleum products with different ratios of petroleum product content in peat and for a saturated peat sample. The obtained results are compared with those of experiments conducted in a calorimetric bomb and recalculated for net calorific value. A satisfactory discrepancy is obtained, which amounts to about 12%. Options have been considered providing for combustion of saturated peat as fuel (burnt per se and combined with a solid fuel) and processing it to produce liquid, gaseous and solid fuels. Peat can be used to solve environmental problems of elimination of emergency spills of crude oil and petroleum products and as an additional resource in solving the problem of finding affordable energy.

EXPERIMENTAL STUDIES OF REINFORCED CONCRETE STRUCTURES WITH CROSS-SHAPED SPATIAL CRACK UNDER TORSION WITH BENDING

2020 ◽  
Vol 92 (6) ◽  
pp. 13-25
Author(s):  
Vl.I. KOLCHUNOV ◽  
◽  
A.I. DEMYANOV ◽  
M.M. MIHAILOV ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Experimental Determination ◽  
Calculation Method ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Design Parameters ◽  
Reinforced Concrete Structures ◽  
Experimental Scheme

The article offers a method and program for experimental studies of reinforced concrete structures with cross-shaped spatial crack under torsion with bending, the main purpose of which is to check the design assumptions and experimental determination of the design parameters of the proposed calculation method. The conducted experimental studies provide an opportunity to test the proposed calculation apparatus and clarify the regularities for determining deflections, angles of rotation of extreme sections, and stresses in the compressed zone of concrete. For analysis, the article presents a typical experimental scheme for the formation and development of cracks in the form of a sweep, as well as characteristic graphs of the dependence of the angles of rotation of end sections.

scholarly journals Bone Morphogenetic Protein in Scaphoid Nonunion: A Systematic Review

2021 ◽  
Author(s):  
Michael M. Polmear ◽  
Ashley B. Anderson ◽  
Paul J. Lanier ◽  
Justin D. Orr ◽  
Leon J. Nesti ◽  
...  
Keyword(s):  
Literature Review ◽  
Bone Morphogenetic Protein ◽  
Controlled Trial ◽  
Scaphoid Nonunion ◽  
Journal Articles ◽  
Level Of Evidence ◽  
Carpal Collapse ◽  
Morphogenetic Protein ◽  
Combination Of Methods

Abstract Background Scaphoid nonunion can lead to carpal collapse and osteoarthritis, a painfully debilitating problem. Bone morphogenetic protein (BMP) has been successfully implemented to augment bone healing in other circumstances, but its use in scaphoid nonunion has yielded conflicting results. Case Description The purpose of this study is to assess the outcomes and complications of scaphoid nonunion treated surgically with BMP. Literature Review A literature review of all available journal articles citing the use of BMP in scaphoid nonunion surgery from 2002 to 2019 was conducted. We included studies that used BMP as an adjunct to surgical treatment for scaphoid nonunions in both the primary and revision settings with computed tomography determination of union. Demographic information, dose of BMP, tobacco use, outcomes, and complications were recorded. A total of 21 cases were included from four different studies meeting inclusion criteria. Clinical Relevance The union rates were 90.5% overall, 100% for primary surgeries, and 77.8% for revision surgeries. Five patients (24%) experienced 11 complications, including four cases (19%) of heterotrophic ossification. Use of BMP in scaphoid nonunion surgery resulted in a 90.5% overall union rate but was also associated with complications such as heterotopic ossification. All included studies used BMP to augment bone graft, screw or wire fixation, or a combination of methods. The efficacy of BMP in scaphoid nonunion is unclear, and a sufficiently powered, randomized controlled trial is needed to determine optimal fixation methods, dosing, and morbidity of the use of BMP. Level of Evidence This is a Level IC, therapeutic interventional study.

The Impact of Classroom Chatter Noise on Comprehension: A Systematic Review

2021 ◽  
pp. 003151252110059
Author(s):  
Anne-Sophie Lamotte ◽  
Aziz Essadek ◽  
Gérard Shadili ◽  
Jean-Michel Perez ◽  
Julien Raft
Keyword(s):  
Systematic Review ◽  
Literature Review ◽  
Teaching Methods ◽  
Classroom Environment ◽  
Field Survey ◽  
Human Life ◽  
Experimental Studies ◽  
Noisy Environment ◽  
Student Comprehension ◽  
The Impact

Communication through discussion and conversations is fundamental to human life; but when such discourse escapes the control of a teacher in the classroom, it becomes little more than chatter. This noise challenges teaching methods and the teaching stance with students. Yet, its impact on comprehension has rarely been studied. The aim of this literature review was to examine the research on the impact of classroom noise generated by chatter on students’ comprehension performance. We adopted the PRISMA (Preferred Reporting Items for Systematic Reviews and Metanalysis) guidelines to examine this literature. This review covered a 10-year period (papers written between 2009 and 2019), with nine experimental studies selected from the 2,954 papers screened. In 89% of these nine studies, there were significant comprehension differences on all tests, revealed when comprehension took place in a noisy environment due to chatter. This review indicated an essential need for a field survey to better understand the impact of chatter on comprehension. Other studies are recommended to highlight any correlation between measured chatter and student comprehension in a real classroom environment.

Experimental Determination of KI for Short Internal Cracks

2001 ◽  
Vol 68 (6) ◽  
pp. 937-943 ◽  
Author(s):  
K. Bearden ◽  
J. W. Dally ◽  
R. J. Sanford
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Edge Crack ◽  
Series Solution ◽  
Experimental Studies ◽  
Experimental Methods ◽  
Internal Crack ◽  
Intensity Factors ◽  
Mode Stress

Since the pioneering discussion by Irwin, a significant effort has been devoted to determining stress intensity factors (K) using experimental methods. Techniques have been developed to determine stress intensity factors from photoelastic, strain gage, caustics, and moire´ data. All of these methods apply to a relatively long single-ended-edge crack. To date, the determination of K for internal cracks that are double-ended by experimental methods has not been addressed. This paper describes a photoelastic study of tension panels with both central and eccentric internal cracks. The data recorded in the experiments was analyzed using a new series solution for the opening-mode stress intensity factor for an internal crack. The data was also analyzed using the edge-crack series solution, which is currently employed in experimental studies. Results indicated that the experimental methods usually provided results accurate to within three to five percent if the series solution for the internal crack was employed in an overdeterministic numerical analysis of the data. Comparison of experimental results using the new series for the internal crack and the series for an edge crack showed the superiority of the new series.

Calculation of Technical Characteristics of the Technical Fleet Vessels Involved in Ensuring Safety of the Offshore Facilities of Oil and Gas Complex

2021 ◽  
pp. 7-13
Author(s):  
S.V. Matsenko ◽  
◽  
V.M. Minko ◽  
A.A. Koshelev ◽  
V.Yu. Piven ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Oil Pollution ◽  
Raw Materials ◽  
Experimental Studies ◽  
Industrial Safety ◽  
Theoretical Studies ◽  
Physical Processes ◽  
Oil Spill Response ◽  
Sea Area

Violation of industrial safety rules during the operation of offshore facilities for the production, storage and transportation of the hydrocarbon raw materials leads in the most cases to pollution of the marine environment with oil and its components. The works on localization and elimination of such pollution are carried out with the help of vessels of the technical support fleet and booms. When developing oil spill response plans at such facilities, a calculated determination of the technical characteristics of vessels and booms is required that are sufficient to carry out the planned activities. The basic design principles for determining the towing capacity of the technical fleet vessels involved in the localization and elimination of oil and oil product spills by trawling methods are given in the article. The calculation is based on theoretical studies performed by the authors of the physical processes occurring during the movement of objects of a mobile trawling order in the sea area. The results obtained during the course of theoretical studies were confirmed by the experimental studies carried out by the authors personally using the real pieces of equipment in the actual development of tasks for training spill containment by trawling. As a result, the empirical dependencies were obtained and experimentally confirmed, which can be used to calculate technical characteristics of the ships as part of the mobile orders and anchor systems as part of stationary orders intended for the localization and elimination of oil pollution. These results can be used, among other things, for the calculated substantiation of the technical characteristics of the technical fleet vessels designed to ensure safety of the offshore facilities for production, storage, and transportation of the hydrocarbon raw materials.

Еarly diagnosis of multiple sclerosis: experience with the use of class G oligoclonal immunoglobulin

2021 ◽  
Vol 26 (3) ◽  
pp. 34-39
Author(s):  
Z. A. Goncharova ◽  
Y. Y. Pogrebnova ◽  
N. M. Yarosh ◽  
S. M.M. Sehweil
Keyword(s):  
Multiple Sclerosis ◽  
Early Diagnosis ◽  
Literature Review ◽  
Demyelinating Disease ◽  
Mcdonald Criteria ◽  
Mri Features ◽  
Oligoclonal Igg ◽  
Relationship Of ◽  
The Relationship

The article presents the literature review and our experience in early diagnosis of multiple sclerosis based on the updated McDonald criteria of 2017. The study included 256 patients with clinic symptoms of probable idiopathic infl ammatory demyelinating disease, including rare and atypical forms of demyelination. As a result of the study the sensitivity and specifi city of the determination of oligoclonal immunoglobulin G in the population of Rostov-on-Don was described for the fi rst time, including dependence of the duration of the disease. The relationship of clinical and MRI features of the fi rst attack of the disease with the probability of determining oligoclonal IgG in the cerebrospinal fl uid is refl ected

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