scholarly journals Thermodynamic Simulation of Simultaneous Extraction of Metals During Waste Processing Industry

2018 ◽  
Vol 20 (2) ◽  
pp. 107
Author(s):  
Zh. Daribaev ◽  
M. Suleimenova ◽  
V. Shevko ◽  
N. Daribaeva
Keyword(s):  
Thermodynamic Simulation ◽  
Experimental Studies ◽  
Industrial Wastes ◽  
Sharp Rise ◽  
Software Complex ◽  
Technogenic Waste ◽  
Waste Dumps ◽  
High Temperature Processing ◽  
The Cost ◽  
Bismuth Chloride

The depletion of ores, a rise in the cost of their extraction, enrichment and processing led in the last 10‒15 years to a sharp rise in prices for tungsten products. Therefore, the processing began to involve technogenic waste ‒ dumps of enrichment factories and metallurgical industries, which previously did not represent the commercial interest on this case, we present the information on the results of the thermodynamic modeling of tungsten and bismuth chloride distillation in the processing of industrial waste using NaCl as a chlorinating agent. To calculate thermodynamic models for the associated extraction of tungsten and bismuth from industrial wastes, the ASTRA-4 software complex was used which created on basis of the maximum entropy of all possible reactions occurring during the retrieval of refractory metals from waste. Thus, the calculations carried out and experimental studies of the main provisions of thermodynamic calculation have shown the possibility of using NaCl salts for bismuth chlorination. At the same time, the maximum degree of sublimation of bismuth not be lower than 98% and can be achieved even at a temperature of 1200 K and a pressure of 0.01–0.1 MPa. At the same time, NaCl is not an effective chlorinating agent for retrieving of tungsten during high-temperature processing of industrial wastes.

THE METHOD OF DETERMINING THE PUNCHING ACTION OF THE READY-MADE DAMAGE ELEMENT OF FRAGMENTATION OF HIGH-EXPLOSIVE WARHEAD

2019 ◽  
Vol 1 (12) ◽  
pp. 41-47
Author(s):  
O. Obukhov ◽  
S. Usenko
Keyword(s):  
High Explosive ◽  
Experimental Studies ◽  
Limited Range ◽  
Software Complex ◽  
Penetration Ability ◽  
The Subject ◽  
Cruise Missiles ◽  
The Cost ◽  
The Impact

The subject of this article is the development of a method for determining the penetration capacity of ready-made elements of damage to a fragmentation and high-explosive warhead. The analysis of the existing methods of determining the penetration capacity of the damage elements indicates their inconsistency with the modern requirements for determining the power of means of destruction of combat parts of missiles, tactical and cruise missiles and aircraft bombs. Existing techniques that were proposed in the late 19th and early 20th centuries are based on the systematization of empirical research and are outdated and have a limited range of applications. Since they do not take into account the zone of contact interacting between the element of the impact and the obstacle and the critical angle of approach, which will determine the ricochet conditions. The article presents the results of the calculated determination of the penetration capacity of the ready-made damage element, taking into account the contact surface of the interaction of the damage element with the obstacle, which are obtained as a result of the calculation modelling in the Ansys Autodyn software complex. Ways to determine the penetration capacity of ready-made destruction elements of fragmentation and high-explosive warhead, taking into account their true geometric shape and excess kinetic energy are proposed in the article. The proposed technique can be used to create the penetration nomograms of the elements of the lesion. The application of computational modeling of the determination of nonograms of penetration ability will allow to abandon a large number of experimental studies with real undermining of the warhead, thereby reducing the cost and speeding up the process of creating, refining and adopting the newest samples of defeat equipment.

scholarly journals Bioethanolic yeasts from dung beetles: tapping the potential of extremophilic yeasts for improvement of lignocellulolytic feedstock fermentation

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Anita Ejiro Nwaefuna ◽  
Karl Rumbold ◽  
Teun Boekhout ◽  
Nerve Zhou
Keyword(s):  
Treatment Process ◽  
Dung Beetles ◽  
Production Costs ◽  
Industrial Wastes ◽  
Major Drawback ◽  
Renewable Fuel ◽  
Extreme Stress ◽  
Pre Treatment ◽  
The Cost ◽  
Simultaneous Saccharification

AbstractBioethanol from abundant and inexpensive agricultural and industrial wastes possesses the potential to reduce greenhouse gas emissions. Bioethanol as renewable fuel addresses elevated production costs, as well as food security concerns. Although technical advancements in simultaneous saccharification and fermentation have reduced the cost of production, one major drawback of this technology is that the pre-treatment process creates environmental stressors inhibitory to fermentative yeasts subsequently reducing bioethanol productivity. Robust fermentative yeasts with extreme stress tolerance remain limited. This review presents the potential of dung beetles from pristine and unexplored environments as an attractive source of extremophilic bioethanolic yeasts. Dung beetles survive on a recalcitrant lignocellulose-rich diet suggesting the presence of symbiotic yeasts with a cellulolytic potential. Dung beetles inhabiting extreme stress environments have the potential to harbour yeasts with the ability to withstand inhibitory environmental stresses typically associated with bioethanol production. The review further discusses established methods used to isolate bioethanolic yeasts, from dung beetles.

Influence of Temperature Fields on the Quality of Dried Wood Products

2021 ◽  
Vol 1038 ◽  
pp. 336-344
Author(s):  
Olena Pinchevska ◽  
Andriy Spirochkin ◽  
Denys Zavialov ◽  
Rostislav Oliynyk
Keyword(s):  
Experimental Studies ◽  
Wood Products ◽  
Temperature Fields ◽  
Drying Process ◽  
Wood Moisture ◽  
Adequate Model ◽  
Heating And Cooling ◽  
White Spots ◽  
The Cost ◽  
Wood Heating

The reasons of white spots appearance in the middle of oak timber are determined. These white spots reduce the cost of the lamina made of oak timbers - the front covering of floorboards. It is proposed to intensify the drying process by using oscillating drying schedules to avoid this defect. A method for calculating the duration of such drying is proposed. This method includes the peculiarities of heating and cooling periods kinetics of oak timbers with 25 mm and 30 mm thickness. The inexpediency of using the oscillation of the drying agent parameters in the range of wood moisture content below 20% has been established. An adequate model for calculating wood temperature and air humidity during wood heating and cooling periods has been developed using heat and mass transfer criteria and experimentally determined oak wood moisture conductivity coefficient. Based on the results of theoretical and experimental studies oscillating drying schedules of different thickness oak timbers are offered. Tests of the proposed schedules in industrial conditions showed no discoloration of the central layers of European oak (Quercus robur) timbers. The drying process duration was reduced by 1.5–2.4 times and energy consumption were reduced by 1.53 times.

Since blood transfusion is linked to the magnitude of the surgical procedure, comparing transfused patients to untransfused patients will always be confounded by infection risks due to factors related to the procedure. To control for these factors one must compare patients transfused with red cells from different sources or prepared in a manner which minimize infection risk. Patients transfused with homologous blood have infection rates several fold higher than recipients of equal values of autologous blood undergoing the same operative procedure (20-23). Homologous blood recipients have significantly longer hospital stays attributed to treating infections. The cost of a blood transfusion exceeds the cost of collection, storage and administration because of transfusion's association with length of stay. In this era of cost-containment the association with prolonged stay may ultimately curtail the use of blood. Homologous blood can be filtered to remove donor leukocytes which may be contributing to immune suppression and infection risk. A prospective randomized trial comparing the infection rates among colorectal cancer patients receiving filtered and unfiltered blood has been conducted (9). There were 17 infectious complications among the 56 recipients of whole blood and one infectious complication among the 48 recipients of filtered blood. Infections were prevented by the seemingly simplistic addition of a $25/filter to every bag of blood transfused. These clinical studies are very convincing: homologous blood transfusion is associated with increased risk of infection in every clinical situation examined. In multivariate analyses transfusion was a significant predictor of infection after consideration of other variables measured and in the majority of those studies transfusion was the single most significant factor. Patients receiving homologous blood exhibited an incidence of infectious complications that was approximately four times higher than patients receiving autologous blood. The association of transfusion with infection is found among patients undergoing surgery for cardiac, orthopedic and gastrointestinal disorders and for trauma as well as among unoperated patients transfused for bums and gastrointestinal bleeding. The observation that nosocomial infections are increased in these studies argues strongly that the association of transfusion with infection is not simply a reflection of transfusion as a marker of tissue destruction and contamination. Infections that develop in transfused patients away from the site of trauma or in the absence of trauma, cannot be attributed to the quantity of tissue destroyed or to the degree of bacterial contamination. Filtered blood can remove leukocytes and prevent postoperative infections. Since filtering blood can significantly reduce the incidence of infection among transfused patients, all transfused blood will be passing through filters in the very near future. EXPERIMENTAL STUDIES RELATING BLOOD TRANSFUSION TO INCREASED RISK OF INFECTION Patients are extremely heterogeneous and even in prospective randomized trials, factors which influence patients' participation affect the outcome despite double-blinding and randomization. In animal studies using syngeneic strains with identical housing, lighting, access to food and water, control over the extent of injury, use of antibiotics and exposure to other variables the influence of a single variable such as blood transfusion can be measured. Dr. Waymack's laboratory has intensively studied parameters which interact with transfusion in

1995 ◽  
pp. 296-296
Keyword(s):  
Blood Transfusion ◽  
Autologous Blood ◽  
Experimental Studies ◽  
Infection Risk ◽  
Infectious Complications ◽  
Risk Of Infection ◽  
Infection Rates ◽  
Homologous Blood ◽  
Increased Risk ◽  
The Cost

scholarly journals INVESTIGATION OF THE METHOD OF PROCESSING HOLES WITH A ROTARY CUP CUTTER WITH SURFACING

2021 ◽  
pp. 1-6
Author(s):  
Bakytzhan Donenbayev ◽  
Karibek Sherov ◽  
Assylkhan Mazdubay ◽  
Aybek Sherov ◽  
Medgat Mussayev ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Cutting Tool ◽  
Large Diameter ◽  
Cutting Tools ◽  
Experimental Studies ◽  
Surface Hardness ◽  
Hard Metal ◽  
Metal Plates ◽  
Study Results ◽  
The Cost

This article presents the experimental study results of the process of rotational friction holes boring using a cup cutter surfaced by STOODY M7-G material. As a result of experimental studies, the following quality indicators were achieved: surface roughness within Ra=10÷1,25 micrometer; surface hardness within HB 212-248. Using a cup cutter surfaced by STOODY M7-G material in case of rotational friction boring of large-diameter holes for large-sized parts can improve processing performance in comparison with cutting tools equipped with hard metal plates and provided the required surface roughness. Preliminary calculations showed that the manufacture of cup cutters from non-instrumental materials reduces the cost of the cutting tool by 5-7 times and the cost of the operation by 1.5-2 times.

scholarly journals Iron reduction from concentrates of hydrometallurgical dressing

2021 ◽  
Vol 64 (10) ◽  
pp. 728-735
Author(s):  
I. A. Rybenko ◽  
O. I. Nokhrina ◽  
I. D. Rozhikhina ◽  
M. A. Golodova ◽  
I. E. Khodosov
Keyword(s):  
Experimental Study ◽  
Thermal Decomposition ◽  
Thermodynamic Modeling ◽  
Iron Reduction ◽  
Solid Phase ◽  
Experimental Studies ◽  
Statistical Processing ◽  
Reducing Agent ◽  
Volatile Components ◽  
Software Complex

The article presents results of theoretical and experimental studies of the processes of iron solid-phase reduction from an iron-containing concentrate obtained as a result of hydrometallurgical dressing of ferromanganese and polymetallic manganese-containing ores with coals of grades D (long-flame) and 2B (brown). The method of thermodynamic modeling using TERRA software complex was used to study the reducing properties of hydrocarbons by calculating equilibrium compositions in the temperature range of 373 - 1873 K. The authors obtained the dependences of compositions and volume of the gas phase formed as a result of the release of volatile components during heating on the temperature for the coals of the grades under consideration. As a result of thermodynamic modeling, the optimal temperatures and consumption are determined, which ensure the complete iron reduction from an iron-containing concentrate. The results of experimental studies were obtained by modern research methods using laboratory and analytical equipment, as well as methods of statistical processing. Results of the coals analysis carried out using the Setaram LabSys Evo thermal analyzer showed that the process of thermal decomposition of coals of the studied grades proceeds according to general laws. The process of thermal decomposition of long-flame coal proceeds less intensively than of brown coal. The results of an experimental study of the processes of thermal decomposition of reducing agents have shown that volumes of the gas phases, formed when coals are heated to a temperature of 1173 K in an argon atmosphere, practically coincide with the calculated values. As a result of thermodynamic modeling and experimental study, the optimal consumption of D and 2B grades of coal is determined at a temperature of 1473 K. The best reducing agent with a minimum specific consumption is long-flame coal of D grade. When determining the optimal amount of reducing agent in charge mixtures during the study of metallization processes, it was found that with an excess of reducing agent, it is possible to achieve almost complete extraction (98 - 99 %) of iron from the concentrate.

scholarly journals PLANNING OF EXPERIMENTAL STUDIES WITH THE PURPOSE OF DEVELOPING THE MODE OF FACING DSTP WITH A THIN SLED VENEER OF WOOD MAHAGONI

2021 ◽  
Author(s):  
Tatyana Efimova ◽  
Tatyana Ishchenko ◽  
S. Dunaev
Keyword(s):  
Wood Species ◽  
Experimental Studies ◽  
Second Order ◽  
Synthetic Materials ◽  
Natural Wood ◽  
Cost Of Production ◽  
Wood Furniture ◽  
The Cost ◽  
Huge Variety

The modern market offers mainly furniture made from traditional materials: chipboard and fiberboard, faced with synthetic materials (films, plastics). However, despite the huge variety of synthetic materials, they cannot convey the original texture, color of natural wood. Furniture made of natural wood and furniture made of panel materials, faced with sliced veneer, are classified as premium furniture due to the high cost and shortage of valuable wood species. To reduce the cost of production, it is proposed to use thin sliced and peeled veneer with a thickness of 0.4 mm. The problem is that the most common veneering defect is glue leakage, which depends on many factors, as well as the lack of clear recommendations for the choice of veneering modes. In this regard, the problem of developing a mode for veneering chipboards with thin sliced veneer of mahogany wood is relevant and requires research. The paper identifies variable factors and factors that remained constant during research. The conditions for conducting experimental studies are also given. To develop a methodology for conducting experimental studies, the method of uniform- rotatable planning of a second-order experiment was used.

scholarly journals An Experimental Study to Evaluate the Impact of the Programming Paradigm in the Testing Activity

2012 ◽  
Vol 15 (1) ◽  
Author(s):  
Simone de Rocio Senger de Souza ◽  
Marllos Paiva Prado ◽  
Ellen Francine Barbosa ◽  
José Carlos Maldonado
Keyword(s):  
Experimental Study ◽  
Experimental Studies ◽  
Programming Paradigm ◽  
Time Restrictions ◽  
Activity Cost ◽  
The Cost ◽  
Programming Paradigms ◽  
The Impact ◽  
Initial Results ◽  
Testing Criteria

Several techniques and criteria are available to help conducting testing activity. The choice for one of them depends on different aspects, such as the time restrictions, ef- fectiveness of the testing criteria or the features of the program under test. In this context, the programming paradigm might influence in the testing activity cost. This paper presents the results of an experimental study to characterize and evaluate the cost and strength of structural and functional testing criteria, comparing object-oriented and procedural programming paradigms. A set of 32 programs from the data structure do- main was considered in this study. The main goals in the execution of this research were: i) to obtain initial results about the investigated questions; ii) to generate artifacts which can be used as basis to define and conduct further experimental studies; iii) to support training and teaching of software testing activity.

DEVELOPMENT OF A SOFTWARE COMPLEX FOR INTELLIGENT TUNING OF OPERATING FREQUENCIES FOR COGNITIVE RADIO SYSTEMS

2021 ◽  
Author(s):  
Е.О. КАНДАУРОВА ◽  
Д.С. ЧИРОВ
Keyword(s):  
Cognitive Radio ◽  
Software Defined Radio ◽  
Experimental Studies ◽  
Spectrum Utilization ◽  
Radio System ◽  
Cognitive Radio System ◽  
Software Complex ◽  
Cognitive Radio Systems ◽  
Software Modules ◽  
Radio Systems

Представлено описание разработанных программных модулей интеллектуальной перестройки рабочих частот для системы когнитивного радио, в которых применяется ранее предложенный алгоритм анализа использования радиочастотного спектра. Также разработаны программные модули для взаимодействия с программно-определяемыми радиосистемами, такими как LimeSDR. Экспериментально показано, что использование алгоритма предсказания занятости частотных каналов позволяет сократить время оперативного сканирования спектра. A description of the developed software modules for intelligent tuning of operating frequencies for the cognitive radio system is presented. These software modules use the previously proposed algorithm of RF spectrum utilization analysis. Also, software modules have been developed for interacting with software-defined radio such as LimeSDR. Experimental studies have shown that the use of an algorithm for predicting the occupancy of frequency channels allows reducing the time of operational scanning of the spectrum.

Approximate Matching Between XML Documents and Schemas with Applications in XML Classification and Clustering

2011 ◽  
pp. 99-124 ◽  
Author(s):  
Guangming Xing
Keyword(s):  
Structural Information ◽  
Experimental Studies ◽  
Feature Representation ◽  
Document Management ◽  
Data Sets ◽  
Structural Classification ◽  
Approximate Matching ◽  
Xml Documents ◽  
Efficiency And Effectiveness ◽  
The Cost

Classification/clustering of XML documents based on their structural information is important for many tasks related with document management. In this chapter, we present a suite of algorithms to compute the cost for approximate matching between XML documents and schemas. A framework for classifying/clustering XML documents by structure is then presented based on the computation of distances between XML documents and schemas. The backbone of the framework is the feature representation using a vector of the distances. Experimental studies were conducted on various XML data sets, suggesting the efficiency and effectiveness of our approach as a solution for structural classification/clustering of XML documents.

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