Method of Treatment of Radioactive Silts and Soils

1996 ◽  
Vol 465 ◽  
Author(s):  
A. P. Varlakov ◽  
I. A. Sobolev ◽  
A. S. Barinov ◽  
S. A. Dmitriev ◽  
S. V. Karlin ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Liquid Radioactive Waste ◽  
Current Method ◽  
Initial Mixture ◽  
Toxic Substances ◽  
Chemical Waste ◽  
Wide Range ◽  
Product Volume ◽  
Better Than

ABSTRACTTo solve the problem of silts and soils that are contaminated with radioactive and toxic substances, the following method has been developed at SIA RADON. The material is mixed with limestone and other components, including up to 70 % (mass) of dried residue of liquid radioactive waste. The mixture is heated at 800 to 1000 °C, shredded, and used to form cement. This cementation process may be used to treat radioactive or other chemical waste.The work demonstrated that in the case of silts, for example, the product volume is reduced by a factor of 1.5 to 3 compared to the initial silts volume. A fast hardening, durable product is obtained, the quality of which is not inferior to that obtained by using the traditional binders. For some parameters, e.g., hardening rate and macroelement leaching, the current method is significantly better than the traditional cementation process. It has also been demonstrated that, over a wide range of parameters, when dry residue of liquid radioactive waste is used in the initial mixture, the part of NOxCan be reduced to nitrogen, thereby reducing NOx emissions.

ANALYSIS OF THE QUESTIONNAIRE FOR ASSESSING THE LEADERSHIP QUALITIES OF STUDENTS

2019 ◽  
Vol 5 ◽  
pp. 430
Author(s):  
Anatoly Maslak
Keyword(s):  
Latent Variables ◽  
Latent Variable ◽  
Theory Of Measurement ◽  
Interval Scale ◽  
Leadership Qualities ◽  
Wide Range ◽  
Measurement Results ◽  
Measuring Tool ◽  
Better Than

The quality of the questionnaire as a measuring tool largely determines the relevance of the results. The aim of the work is to analyze the quality of the questionnaire as a measuring tool used to evaluate the latent variable "leadership qualities of students". The study was conducted within the framework of the theory of measurement of latent variables, which has important advantages. First of all, the latent variable is determined operationally, through a set of indicators (questionnaire items), the more indicators, the higher the accuracy of the latent variable measurement. The latent variable and indicators are measured on the same interval scale in logits. This allows the use of a wide range of statistical procedures for the analysis of measurement results. The analysis of the following aspects of the quality of the questionnaire as a measuring tool: the presence of extreme indicators in the test, the compatibility of a set of indicators, the compliance of the questionnaire to the level of students on the measured latent variable, the uniformity of the distribution of indicators on the interval scale. The indicators that differentiate students with high and low levels of leadership qualities better than others are highlighted. Recommendations on the adjustment of the questionnaire as a measuring tool for assessing the leadership qualities of students are given. 

scholarly journals On the advances to obtain excellent and repeatable mechanical properties and build quality of LaserForm® Ti gr23 (A) across whole build platform

2020 ◽  
Vol 321 ◽  
pp. 03015
Author(s):  
Anthony Beckers ◽  
Gokula Krishna Muralidharan ◽  
Karel Lietaert ◽  
Nachiketa Ray ◽  
Pierre Van Cauwenbergh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Gas Flow ◽  
Hot Isostatic Pressing ◽  
Fatigue Properties ◽  
Powder Bed ◽  
Part Quality ◽  
Metal Printing ◽  
Wide Range ◽  
Better Than

Direct Metal Printing (DMP) or Laser Based Powder Bed Fusion (L-BPF) enables manufacturing of highly complex geometries which are used in a wide range of applications - healthcare to aerospace. Producing these products with excellent and consistent part quality in terms of density and mechanical properties is key. DMP ProX® 320 machine has been used for over 10 years for this purpose. In this study, the key improvements made on the process stability for targeting consistent build quality across build platform and repeatability have been evaluated. The quality is assessed by determining the density, mechanical properties and surface roughness of direct metal printed LaserForm® Ti gr23 (A). The main finding from the study is that the use of the optimized gas flow enables production of LaserForm® Ti gr23 (A) with consistent and improved mechanical properties across the whole build platform. Moreover, there is no need any more for hot isostatic pressing to ensure good fatigue properties. The elongation strain to failure increased by 15 % to 20 %, which is 4-5 % higher than ASTM F3001 specifications. The axial fatigue limit (5x106 loading cycles) was 637 MPa (R=0.1), which is as good as or even better than annealed wrought Ti6Al4V.

scholarly journals Optimized Uplink Scheduling Model through Novel Feedback Architecture for Wimax Network

2019 ◽  
Vol 9 (1) ◽  
pp. 1353-1359
Keyword(s):  
Quality Of Experience ◽  
User Mobility ◽  
Broadband Wireless ◽  
Bandwidth Request ◽  
Uplink Scheduling ◽  
Scheduling Model ◽  
Wide Range ◽  
Video And Audio ◽  
Better Than

Broadband Wireless Access has drawn the fine attention due to the wide range of data requirement and user mobility all the time. Moreover, WiMAX provides the best QoE (Quality of Experience) which is based on the IEEE 802.16 standards; this includes several services such as data, video and audio. However, in order to provide the effective and smooth experience i.e. QoS scheduling plays one of the critical part. In past several mechanism has been proposed for effective scheduling however, through the research it is observed that it can be furthermore improvised hence in this we propose a mechanism named as OUS (Optimized Uplink Scheduling) which helps in improvising the QoS. In here, we have proposed a novel feedback architecture and proposed optimized scheduling which helps in computing the bandwidth request this in terms helps in reducing the delay as well as jitter. Moreover, the performance evaluation is performed through extensive simulation by varying the different SS and frequency and the results analysis confirms that our mechanism performs way better than the existing algorithm.

Application of the Dry Polyfunctional Additives at Radioactive Waste Cementation

2003 ◽  
Author(s):  
Andrey P. Varlakov ◽  
Konstantin M. Efimov ◽  
Valeri N. Tchernonojkine ◽  
Aleksandr S. Barinov ◽  
Olga A. Gorbunova
Keyword(s):  
Radioactive Waste ◽  
Liquid Radioactive Waste ◽  
Aggregation State ◽  
Technological Processes ◽  
Cement Compound ◽  
Liquid Condition ◽  
Solid Radioactive Waste ◽  
The Cost ◽  
Polyfunctional Additive

One of the known methods directed to improving of the technological cementation process, the increasing quality of a cement compound and degree of radioactive waste incorporating into a final product, is use of the various additives to a cement compound. At present there are technological processes where one or two additives in a dry loose or liquid condition in quantity of 1–10% are used. The application of these additives is directed, as a rule, to improving of one or two properties of a cement compound. The magnification of a quantity of the additives and use of them in a different aggregation state is connected with rise in the cost of the technological process. At Institute of Ecology and Technology Problems and Moscow SIA “Radon” the polyfunctional modifying additives representing dry mixtures of original macro- and microadditives to cement have been developed. The polyfunctional additive is introduced by traditional, reliable and inexpensive equipment directly into liquid radioactive waste and intermixed together with the rest of cement. The quantity of additive varies from 5 up to 20% of cement weight. The additives considerably improve all regulated properties of a cement compound (compressive strength, radionuclides leaching, frost resistance, biological resistance, etc.) and allow modifying the required properties (penetrating ability, viability, disintegration, terms of setting, viscosity etc.). Such additives are used both at cementation of solid radioactive waste and cementation of liquid radioactive waste having a complicated chemical composition, for example, containing simultaneously boric acid, sulphates and great quantity of organic compounds. It is important, that the components of the additives did not change the action in a mixture with other ones. In the report the compositions of the polyfunctional additives developed for various waste and technological processes, their properties and results of practical application are represented.

scholarly journals Modern Oxidizing and Photo Oxidative Methods of Complexons Destruction in Liquid Radioactive Waste

10.12737/8234 ◽  
2015 ◽  
Vol 4 (1) ◽  
pp. 68-83
Author(s):  
Камруков ◽  
A. Kamrukov ◽  
Новиков ◽  
D. Novikov
Keyword(s):  
Hydrogen Peroxide ◽  
Radioactive Waste ◽  
Potassium Permanganate ◽  
Uv Radiation ◽  
Production Efficiency ◽  
Liquid Radioactive Waste ◽  
Special Equipment ◽  
Processing Efficiency ◽  
Wide Range ◽  
Xenon Lamps

State-of-the-art analysis for oxidizing technologies related to destruction of complexons and metalloorganic complexes in liquid radioactive waste has been carried out. Ways already put into practice, as well as the experimental ones have been considered. Oxidation by potassium permanganate and hydrogen peroxide and also ozonization and photo oxidation have been considered in detail. It has been shown that oxidation by potassium permanganate with subsequent filtration leads to decrease of isotopes activity, but hereby a considerable volume of manganese dioxide is formed. The ozonization application allows reduce considerably the liquid radioactive waste (LRW) volume, but along with this ozone is the extremely toxic and explosive substance demanding a special equipment for its production. Efficiency of oxidation by hydrogen peroxide and photo oxidation without catalysts is low. The special attention has been paid to combined oxidizing methods (AOP) based on use of ultra-violet (UV) radiation together with ozone and/or hydrogen peroxide. Such methods allow apply the strongest oxidizer – hydroxyl radical – for LRW processing. Efficiency of AOP-methods and their technological capabilities are substantially defined by characteristics of used UV radiation sources. A detailed analysis for a wide range of UV radiation possible sources (low and average pressure mercury lamps, amalgamate lamps, excimer lamps, light-emitting diodes and pulse xenon lamps) has been carried out, their comparative assessment has been executed. Great potential opportunities for the pulse xenon lamps providing a continuous range of radiation in UV area and high intensity for a stream of high-vigorous photons have been noted.

scholarly journals Applying of Seawater Desalination Technologies for the Pre-Evaporation of Liquid Radioactive Waste

2020 ◽  
Vol 18 ◽  
pp. 57-64
Author(s):  
V. P. Kravchenko ◽  
◽  
S. V. Surkov ◽  
Hussam Ghanem ◽  
◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Liquid Radioactive Waste ◽  
Salt Content ◽  
Design Parameters ◽  
Source Water ◽  
Vapor Compression ◽  
Seawater Desalination ◽  
Wide Range ◽  
Desalination Technology ◽  
The Cost

Processing of liquid radioactive waste (LRW) includes evaporation followed by vitrification. Reducing the energy consumption of evaporation of LRW is an urgent task. In the article, an attention is paid to the fact that similar technical and economic problems are solved with the desalination of seawater. It is proposed to use well-developed seawater desalination technologies for preliminary evaporation of LRW. For a detailed analysis, desalination technology with mechanical vapor compression (MVC) was selected. This technology is energy-saving because it implements the heat pump principle. MVC technology is highly efficient, simple, and does not lead to the generation of secondary radioactive waste. A mathematical model of a single-stage desalination plant with MVC has been developed, taking into account that the thermodynamic cycle of this process is open. Since there are no data on the physical properties of LRW in the literature, the properties of sea water were used. The design and operational parameters were optimized in order to reduce the cost of 1 m3 of evaporated water. It has been established that the main design parameters affecting the cost of evaporated water are the degree of vapor compression in the compressor and the heat exchange surface area of the evaporatorcondenser. The influence of these parameters on capital and operating costs is shown. The optimal combinations of these parameters are determined. To ensure the optimal operating mode of the installation, it is necessary to maintain the optimum salt content of boiling brine, which is determined by the rate of consumption of the source water. The optimal values of these parameters are calculated in a wide range of salt content of the source water. It is shown that, at low salinity of the initial LRW, evaporation is advisable to be carried out in a multi-stage installation. As a result of the calculations, it was found that the specific cost of evaporation of liquid radioactive waste with an initial salt concentration of 10% to a salt content of 20% using the desalination technology with mechanical vapor compression is 0.843 USD/m3.

scholarly journals The Nature, Extent and Survivorship of Biofouling  Organisms at Different Hull Locations on Various Vessel Types

2021 ◽  
Author(s):  
◽  
Ashley D M Coutts
Keyword(s):  
Cost Effective ◽  
Secondary Level ◽  
Percentage Cover ◽  
Wide Range ◽  
International Attention ◽  
Assessment Approach ◽  
Correct Application ◽  
To Receive ◽  
Better Than

<p><b>The importance of vessel biofouling as a vector for the dispersal of non-indigenousmarine species (NIMS) is only just beginning to receive international attention. At thetime of commencing this study, there was a considerable lack of knowledge surroundingwhich vessels, hull locations, levels and types of biofouling pose the greatestbiosecurity risk. Therefore, the aim of this study was to investigate the nature, extentand survivorship of biofouling organisms on various vessel types at different hulllocations and offers a pragmatic risk assessment approach for managing this threat.</b></p> <p>The results of this thesis found that the recruitment, persistence, distribution, abundanceand species composition of biofouling on vessel hulls is influenced by many factorsincluding: 1) the presence/absence, age and type of anti-fouling coating; 2) voyageduration and route; and 3) port residency period. Therefore, higher levels of biofouling(species richness, percentage cover, and biomass), including NIMS are more likely toaccumulate and persist on vessels (and in hull locations) that: 1) lack and/or possess old,ineffective, damaged, inappropriate or unsuitable anti-fouling coatings; 2) spendprolonged periods stationary in ports; 3) travel at slow speeds (i.e. <10 knots); 4) haveshort voyage durations; and 5) remain at similar latitudes.</p> <p>Prevention is clearly better than a cure, hence the correct application and maintenanceof suitable anti-fouling coatings to the entire submerged hull surface of vessel hulls,including niche areas is the most cost-effective way of minimising the unwantedtranslocation of biofouling organisms and NIMS. However, the results of this thesisdemonstrate that if biofouling organisms colonise and establish on a vessel's hull,voyage speed alone is not capable of providing a reliable secondary level of defenceagainst the unwanted dispersal of NIMS. Clearly, the survivorship of biofoulingorganisms was highest amongst vessels that travelled at slow and medium speeds (e.g.</p> <p><10 knots). Therefore, given that accumulation of biofouling follows a successionalprocess and NIMS are more likely to be associated with higher levels of biofouling,vessels that travel at slow and medium speeds are more likely to pose the greatest riskof translocating NIMS on a vessel by vessel scale. However, despite the observationthat faster vessels reduce the diversity, quantity and quality of sessile biofoulingorganisms in laminar flow areas of the hull, a wide range of sessile, sedentary andmobile organisms were still cable of survival in areas protected from harsh hydrodynamically forces commonly referred to as niche areas, particularly within sea-chests.</p>

scholarly journals DEVELOPMENT OF NOVEL UNIVERSAL BIOTECHNOLOGIES FOR OBTAINING VALUABLE PRODUCTS FROM A WIDE RANGE OF WASTES

2020 ◽  
pp. 5-17
Author(s):  
Oleksandr Tashyrev ◽  
Valery Shevel ◽  
Vira Hovorukha ◽  
Olesia Havryliuk ◽  
Iryna Sioma
Keyword(s):  
Radioactive Waste ◽  
Food Waste ◽  
Methodological Approach ◽  
Liquid Radioactive Waste ◽  
Total Carbon ◽  
Toxic Compounds ◽  
Industrial Implementation ◽  
Wide Range ◽  
Waste Degradation ◽  
Waste Destruction

Despite the achievements in development of environmental biotechnologies, the total amount of waste is continuously increasing. Development of novel methodological approach is the only possible effective solution of problems. The aim was to develop the base of universal biotechnologies for effective treatment of all four classes of waste and obtain valuable products. To obtain biotechnologically promising results the method of thermodynamic prognosis of microbial interaction with toxic compounds (multi component food waste and filtrate, metal containing wastewater, radioactive waste) was developed. The following results of food waste degradation were obtained: time detention T=6 days, coefficient of waste destruction Kd=90; biohydrogen yield – 120 L from 1 kg of waste. Wastewater treatment provided purification from 10020 to 20 ppm of total Carbon and toxic metals. Purification of liquid radioactive waste allowed several orders decreasing its activity within 4-5 days. These biotechnologies are promising for their industrial implementation in order to stop pollution of environment and preserve ecosystems.

Study of Thermodynamic Modeling of Isothermal and Isobaric Binary Mixtures in Vapor-Liquid Equilibrium (VLE) of Tetrahydrofuran with Benzene (303.15 K) Cyclohexane (333.15 K), Methanol (103 kPa), and Ethanol (100 kPa)

Thermo ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 286-296
Author(s):  
Leonardo Steyman Reyes Fernández ◽  
Eliseo Amado-Gonzaléz ◽  
Erik Germán Yanza Hurtado
Keyword(s):  
Binary Mixtures ◽  
Binary Data ◽  
Chemical Waste ◽  
Uniquac Model ◽  
Isothermal System ◽  
Pharmaceutical Industries ◽  
Vle Data ◽  
Activity Coefficient Models ◽  
Better Than

Tetrahydrofuran (THF) is an aprotic solvent with multiple applications in diverse areas of chemical, petrochemical, and pharmaceutical industries with an important impact in chemical waste liquid with other solvents. In this work, 51 available VLE data, for isothermal binary mixtures of THF(1) + Benzene(2) and THF(1) + Cyclohexane(2) at 303.15 and 333.15 K, respectively, and isobaric THF(1) + Methanol(2) at 103 kPa and THF(1) + Ethanol(2) at 100 kPa were used in the development of the activity coefficient models. The quality of experimental data was checked using the Herington test. VLE binary data was correlated with models Wilson, NRTL UNIQUAC, and UNIFAC to obtain binary parameters and activity coefficients. The best thermodynamic consistency when conducting the Herington test for the VLE data was found for the THF(1) +Cyclohexane(2) isothermal system and THF(1) + Ethanol(2) isobaric system. The UNIQUAC model for isothermal systems THF(1) + Benzene(2) and THF(1) + Cyclohexane(2), the NRTL model for the isobaric system THF(1) + Methanol(2), and the UNIQUAC model for THF(1) + Ethanol(2) perform better than the other models.

scholarly journals The Nature, Extent and Survivorship of Biofouling  Organisms at Different Hull Locations on Various Vessel Types

2021 ◽  
Author(s):  
◽  
Ashley D M Coutts
Keyword(s):  
Cost Effective ◽  
Secondary Level ◽  
Percentage Cover ◽  
Wide Range ◽  
International Attention ◽  
Assessment Approach ◽  
Correct Application ◽  
To Receive ◽  
Better Than

<p><b>The importance of vessel biofouling as a vector for the dispersal of non-indigenousmarine species (NIMS) is only just beginning to receive international attention. At thetime of commencing this study, there was a considerable lack of knowledge surroundingwhich vessels, hull locations, levels and types of biofouling pose the greatestbiosecurity risk. Therefore, the aim of this study was to investigate the nature, extentand survivorship of biofouling organisms on various vessel types at different hulllocations and offers a pragmatic risk assessment approach for managing this threat.</b></p> <p>The results of this thesis found that the recruitment, persistence, distribution, abundanceand species composition of biofouling on vessel hulls is influenced by many factorsincluding: 1) the presence/absence, age and type of anti-fouling coating; 2) voyageduration and route; and 3) port residency period. Therefore, higher levels of biofouling(species richness, percentage cover, and biomass), including NIMS are more likely toaccumulate and persist on vessels (and in hull locations) that: 1) lack and/or possess old,ineffective, damaged, inappropriate or unsuitable anti-fouling coatings; 2) spendprolonged periods stationary in ports; 3) travel at slow speeds (i.e. <10 knots); 4) haveshort voyage durations; and 5) remain at similar latitudes.</p> <p>Prevention is clearly better than a cure, hence the correct application and maintenanceof suitable anti-fouling coatings to the entire submerged hull surface of vessel hulls,including niche areas is the most cost-effective way of minimising the unwantedtranslocation of biofouling organisms and NIMS. However, the results of this thesisdemonstrate that if biofouling organisms colonise and establish on a vessel's hull,voyage speed alone is not capable of providing a reliable secondary level of defenceagainst the unwanted dispersal of NIMS. Clearly, the survivorship of biofoulingorganisms was highest amongst vessels that travelled at slow and medium speeds (e.g.</p> <p><10 knots). Therefore, given that accumulation of biofouling follows a successionalprocess and NIMS are more likely to be associated with higher levels of biofouling,vessels that travel at slow and medium speeds are more likely to pose the greatest riskof translocating NIMS on a vessel by vessel scale. However, despite the observationthat faster vessels reduce the diversity, quantity and quality of sessile biofoulingorganisms in laminar flow areas of the hull, a wide range of sessile, sedentary andmobile organisms were still cable of survival in areas protected from harsh hydrodynamically forces commonly referred to as niche areas, particularly within sea-chests.</p>

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