Статті в журналах: "Resource durability"

1

Котляревский and Vladimir Kotlyarevskiy. "Assessment of Durability Resource of Bent Underground Main Pipelines." Safety in Technosphere 1, no. 6 (December 25, 2012): 28–35. http://dx.doi.org/10.12737/155.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Cherepanov, Anatoliy. "THE EFFECT OF FRICTION PAIR WEAR ON THE LIFE OF THE MACHINE." Modern Technologies and Scientific and Technological Progress 2022, no. 1 (May 16, 2022): 71–72. http://dx.doi.org/10.36629/2686-9896-2022-1-71-72.

Повний текст джерела

Анотація:

The influence of the degree of wear of the friction pair on the durability and resource of mechanisms and machines is considered. The passage of liquid or gas, a decrease in the discharge pressure in the cylinders, runout and dynamic loads on components and parts increase with the wear of friction pairs, which as a result leads to a decrease in the durability and resource of machines

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Naik, Viren, Georges Savoldelli, Deven Chandra, and Hwan Joo. "Durability of Non-Technical Skills Following Crisis Resource Management Training." Simulation In Healthcare: The Journal of the Society for Simulation in Healthcare 2, no. 1 (2007): 59. http://dx.doi.org/10.1097/01266021-200700210-00036.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Zhou, Bo, Wen Liang Liu, and Xu Hui Liu. "DOI of Local Information Service Database Based on CALIS-Standard." Applied Mechanics and Materials 241-244 (December 2012): 3130–33. http://dx.doi.org/10.4028/www.scientific.net/amm.241-244.3130.

Повний текст джерела

Анотація:

The unstable linking of network and difficult finding on internet make information resources lacking of durability so the sharing of digital information resource and the location management has become the key research of the serving of information resources. The paper puts forward CALIS-DOI model fitting the requirements of local information service database construction by analyzing application situation of DOI in building local information resources services and fully considering the functions of CALIS in building of local information resources service. The model will be put into the local information resource serving systems and serve for digital location and information transmit.

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Voronov, A. N., and M. N. Kostomakhin. "Assessment of the durability of self-propelled agricultural machines." Sel'skohozjajstvennaja tehnika: obsluzhivanie i remont (Agricultural Machinery: Service and Repair), no. 9 (September 5, 2021): 50–53. http://dx.doi.org/10.33920/sel-10-2109-07.

Повний текст джерела

Анотація:

Material according to reliability of agricultural machinery and its main indicators which are characterized by measurement of resource parameters of technical condition of details and interfaces is presented in article. The possibility of an assessment of a resource of car/system or the unit is considered, at technical service of cars by means of the generalized coefficient characterizing their current technical condition

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Savadogo, Nafissatou, Adamah Messan, Kinda Hannawi, William Prince Agbodjan, and François Tsobnang. "Durability of Mortar Containing Coal Bottom Ash as a Partial Cementitious Resource." Sustainability 12, no. 19 (September 30, 2020): 8089. http://dx.doi.org/10.3390/su12198089.

Повний текст джерела

Анотація:

This research work focuses on the study of the durability of composite cements based on coal bottom ash powder produced by SONICHAR in Niger. After a physicochemical and environmental characterization of the coal bottom ash powder, mortar test specimens were made. In these specimens, 10%, 15% and 20% of cement were replaced by identical mass percentages of coal bottom ash powder. Durability studies focused on the determination of the chloride ions apparent diffusion coefficient, the measurement of the depth of carbonation and the accelerated ammonium nitrate leaching. The influence of carbonation and leaching were examined using the following parameters: pore distribution, gas permeability, porosity accessible to water, capillary absorption and electrical resistivity. The results show that the incorporation of coal bottom ash powder into CEM I leads to an increase in the depth of carbonation. This increase is more significant when the substitution rate exceeds 10%. In the leaching test, the partial substitution of coal bottom ash powder in CEM I up to 20% does not significantly affect the durability parameters of the composites compared to the control mortar. Diffusion test shows that for mortars containing less than 15% substitution, there is no significant influence on the chloride diffusion coefficient. A slight decrease is observed for mortar containing 20% substitution.

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Chunchu, Bala Rama Krishna, and Jagadeesh Putta. "Effect of Recycled Plastic Granules as a Partial Substitute for Natural Resource Sand on the Durability of SCC." Resources 8, no. 3 (July 27, 2019): 133. http://dx.doi.org/10.3390/resources8030133.

Повний текст джерела

Анотація:

This investigation is focused on durability studies of binary blended self-compacting concrete (SCC) with the replacement effect of electronic plastic waste, namely high-impact polystyrene (HIPS) granules as partial sand. In the current investigation, for all the SCC mixes, cement is replaced with pozzolanic material fly ash in the binder content of 497 kg/m3 and an adopted water-to-binder ratio of 0.36. Durability properties such as porosity, water absorption, and sorptivity are assessed for the curing periods of 28 and 90 days on SCC specimens produced with HIPS (0%–40% replacement by volume of sand). Both surface and internal water absorption rates were found to be minimal for SCC with HIPS. Replacement of HIPS up to 30% in SCC exhibited improved trends for all tests results. Reported durability parameter values were within permissible limits and revealed the excellent performance of HIPS in SCC. The optimum durability values can be attributed to the dense microstructure of SCC obtained with the combined effect of HIPS and fly ash. The continuous gradation of aggregates in the matrix reduced porosity due to the spherical shape of HIPS; additionally, the hydrophobicity of HIPS inhibits moisture migration in SCC. The additional benefits of fly ash, such as pozzolanic action and the filler effect at the interfacial transition zone (ITZ) are also major contributions to the long-term performance of durability. Electronic plastic waste replacement for fine aggregates in concrete compensates for the disposal problem and conserves natural sand.

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Lobanov, L. M. "On the implementation of the target program of scientific research of the NAS of Ukraine Reliability and durability of materials, structures, equipment and constructions (transcript of report at the meeting of the Presidium of the NAS of Ukraine, December 9, 2020)." Visnik Nacional'noi' academii' nauk Ukrai'ni, no. 01 (January 25, 2021): 28–33. http://dx.doi.org/10.15407/visn2021.01.028.

Повний текст джерела

Анотація:

The report presents the most important results of the target research program of the NAS of Ukraine “Reliability and durability of materials, structures, equipment and constructions” (“Resource-2”) in 2016-2020, aimed at solving a set of problems, development and implementation of measures and tools to ensure the reliability, durability and safe operation of responsible long-term facilities related to the basic needs of the country. It is proposed to launch a new targeted research program of the NAS of Ukraine “Scientific and technical problems of monitoring, evaluation and extension of life of structures, equipment and constructions of long-term operation” for 2021-2025 (“Resource-3”).

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Rutkevych, Volodymyr. "EXPERIMENTAL RESOURCE STAND RESEARCH OF THE GOLDEN DIVISION DISTRIBUTOR." ENGINEERING, ENERGY, TRANSPORT AIC, no. 3(106) (November 29, 2019): 80–86. http://dx.doi.org/10.37128/2520-6168-2019-3-10.

Повний текст джерела

Анотація:

The article discusses and analyzes the operating conditions of a modern hydraulic drive. Despite the difficult operating conditions of modern agricultural machinery (difficult working conditions, frequent changes in the technological load on the working bodies, low quality of the working fluid, increased dust content and temperature fluctuations), the hydraulic drive is its main reliable element. The basis of hydraulic drives is hydraulic spool type devices, they remain the main components of a modern hydraulic drive, are able to increase energy, dynamic, cost characteristics and increase the reliability and durability of this drive. The advantages, disadvantages and directions of improvement of this drive are noted. The modern directions of development of the hydraulic drive aimed at increasing the reliability, durability and adaptability to changing the technological load on the working bodies are considered. A booth design is proposed that allows to investigate a resource study of the developed spool splitter of a forage stem feeder. As a result of the research at the initial stage, some shortcomings in the structural implementation of the developed spool of the flow divider at the time up to 2·104 cycles were revealed. After analyzing the operating conditions and making changes to the design of the stem feeder spacer spacer and retesting, the spacer spacer showed stable operation, with more than 6.6·105 load cycles.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Lei, Jun Qing. "Research on Durability of Coastal Concrete Bridges." Advanced Materials Research 374-377 (October 2011): 2167–70. http://dx.doi.org/10.4028/www.scientific.net/amr.374-377.2167.

Повний текст джерела

Анотація:

The work presented in this paper focuses on durability of concrete bridges, which is worldwide concerned nowadays because concrete bridges will deteriorate and damage under the natural environment and the long-term usage. The shortage in bridges durability performance will result in severe environment problems; energy sources matters and economic issues. Quickly developed coastal cities and transportion, due to large-scale expansion of themselves and exploitation of ocean resource, have to face rigorous marine climate. Hence, the studies the authors have performed showed that as a civil engineer it is important to learn the research and countermeasure actuality on durability of coastal concrete bridges. According to current research, the existing problems as well as objectives for further studies are also indicated .

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Попов, Dmitriy Popov, Патюков, and S. Patyukov. "PARTICULAR OPERATING CONDITIONS OF THE WORKING BODIES OF BUILDING AND ROAD MACHINES AND FACTORS AF-FECT THEIR RESOURCE." Voronezh Scientific-Technical Bulletin 4, no. 1 (April 15, 2015): 85–94. http://dx.doi.org/10.12737/10908.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Фомичов, Петро Олександрович, Тетяна Сергіївна Бойко та Олександр Олександрович Севостьянов. "Метод расчета усталостного повреждения регулярных зон крыла самолета при случайном нагружении на этапах типового полета". Aerospace technic and technology, № 3 (27 травня 2021): 13–23. http://dx.doi.org/10.32620/aktt.2021.3.02.

Повний текст джерела

Анотація:

In accordance with the airworthiness standards, the aircraft structure must be operationally survivable, it means that structure must be able to remain efficiency in the presence of admissible damage. But, accumulating above than a certain level, damages cause fatigue failure of the structure, in the form of micro- and submicrocracks, thus reducing its strength characteristics. Currently, several approaches have been formed to ensure the safety of an aircraft structures in terms of strength. One of them is ensuring a safe resource (safe durability). This principle implies that during the specified service life of the product, no damage will occur in it, reducing the strength below the permissible level. The aircraft resource is limited “from above” by the durability of the regular zones of airframe. Therefore, predicting the durability of an aircraft wing structure at the design stage is a fundamental engineering problem to ensure its safety and economic efficiency. At the same time, the first step in dealing with aircraft fatigue damage at the design stage is the collection and assessment of the operational loads of the analog aircraft. However, at the design stage of a new aircraft model, obtaining such data is not always possible. Therefore, the purpose of this article is to develop a method for calculating fatigue damage at the stage of cracking and assessing the durability of regular zones of a transport aircraft wing, taking into account the conditions of its operation. The tasks to be solved are: to isolate the factors that determine the durability of the aircraft at flying in turbulent air; to take into account the asymmetry of loads and accumulated damage that occurs at each stage during the entire flight of the aircraft; to determine the aircraft's resource depending on the profile of a typical flight. The method is based on a standardized atmospheric turbulence model, typical flight profiles, fatigue characteristics of materials, the hypothesis of linear summation of damages and calculation based on nominal stresses. As result, comparison between the calculated integral repeatability of overloads and equivalent bending moments with the results of processing flight test data showed good agreements. Conclusions. The scientific novelty of the work lies in the fact that a method for calculating the fatigue damage of the regular wing zones, taking into account the expected flight profile of the aircraft was developed. This means that the proposed method makes it possible to carry out a preliminary assessment of the resource when designing an airplane without using data on the operational loads of an analogue airplane, and also estimate the residual resource of the airplane during its operation.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Мордвінцева, І. О., and В. О. Пильов. "SIMPLIFIED BOUNDARY CONDITIONS AT CERTAIN RESOURCE DURABILITY OF PISTONS AT DIFFERENT DESIGN STAGES." Internal Combustion Engines, no. 2 (September 24, 2019): 26–30. http://dx.doi.org/10.20998/0419-8719.2019.2.05.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Makhutov, N. A., Yu K. Petrenya, M. M. Gadenin, and S. V. Ivanov. "Factors of estimation of stress states, durability, and resource of critical threaded connections." Inorganic Materials 51, no. 15 (December 2015): 1479–89. http://dx.doi.org/10.1134/s0020168515150121.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Carter, Suzanne M., and Timothy W. Ruefli. "Intra-Industry Reputation Dynamics Under a Resource-Based Framework: Assessing the Durability Factor." Corporate Reputation Review 9, no. 1 (March 2006): 3–25. http://dx.doi.org/10.1057/palgrave.crr.1550006.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Chidiac, S. E., and L. M. Federico. "Effects of waste glass additions on the properties and durability of fired clay brickThis article is one of a selection of papers published in this Special Issue on Masonry." Canadian Journal of Civil Engineering 34, no. 11 (November 2007): 1458–66. http://dx.doi.org/10.1139/l07-120.

Повний текст джерела

Анотація:

The optimization of the production of fired clay brick is essential for the sustainability of the clay brick industry. While there exist areas for improvement of these bricks’ properties when they are used in severe climates, concerns — including nonrenewable resource depletion, increasing energy costs, and waste management — have become increasingly important in Canadian and global industries. One strategy to address these concerns is to use waste additives as fluxing agents in bricks. Use of these additives can decrease the dependency of the industry on nonrenewable resources and can improve brick strength and durability. The effect nonrecycled waste glass additives have on fired brick durability and mechanical and transport properties was investigated in this study. The variables studied were waste glass particle size and percentage added by mass. Microstructure was investigated using mercury intrusion porosimetry to determine the effect on pore structure. The results yielded an optimal percentage addition of waste glass.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

Koval'chuk, Oleksandr, Roman Berezhnyj, Volodymyr Nezhebovs'kyj, and Oleksandr Ustynenko. "ANALYSIS OF TENSENESS AND DURABILITY OF THE MAIN PARTS FOR THE CUTTING PART OF UKD 200-500 COAL SHEARER." Cutting & Tools in Technological System, no. 95 (December 26, 2021): 71–79. http://dx.doi.org/10.20998/2078-7405.2021.95.08.

Повний текст джерела

Анотація:

JSC "Kharkiv Machine-Building Plant "Svitlo Shahtarja" has created and introduced into serial production a new generation UKD200-500 coal shearer. The most loaded element of the shearer is its cutting part. It is a three-stage reducer with an electric motor. Calculations for the strength and durability of gearing, shafts, bearings, spline, pinned and hinge joints have been carried out. The modeling of the stress-strain state for the main parts and assemblies by the finite element method has also been carried out. Calculations have shown that the strength and durability of all parts is ensured. Consequently, the required durability of 15000 hours and the average resource before major overhaul are not less than 800...1000 thousand tons are provided.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Ionov, Pavel A., Petr V. Senin, and Aleksey V. Stolyarov. "Modeling of Stress-Strain State in Connection Resource Defines of Volumetric Hydraulic Drive." Mordovia University Bulletin, no. 4 (December 28, 2018): 537–51. http://dx.doi.org/10.15507/0236-2910.028.201804.537-551.

Повний текст джерела

Анотація:

Introduction. The article explores the stress-strain state of a distribution pair of aggregates of a volumetric hydraulic drive and the search for ways to increase its durability. Materials and Methods. In the process of studying, the generally accepted principles of the theories of friction, reliability, elasticity, mechanisms and machines, and mathematical modeling were used. To simulate the stress-strain state, an engineering analysis system ANSYS was used. Distribution pairs of hydraulic pumps 313.3.112, GST-112 and Sauer Danfoss 90R075 were chosen as objects of study. Results. As a result of the study there were obtained values of the real contact stresses and long-term current stress on the distribution of pairs of units of volumetric hydraulic drive: the 313.3.112 hydraulic pump is 26,93 MPa; for GTS-112 water pump is of 22.21 MPa for the Sauer Danfoss 90R075 hydraulic pump is 27,12 MPa. It is revealed that the area located on the discharge side is a subject to the greatest loads. This is the cause of one-sided wear of spherical surfaces, which is quite common in units decommissioned. The values of contact stresses in the joints hardened by the method of electric spark machining are on average 1.4 and 9.4 % lower than in not unhardened. In the process of electric spark machining there is a redistribution of stresses on the surface that leads to a decrease of the operating load in the connections. Conclusions. The study allowed modelling the stress-strain state in new and hardened distribution pairs of volumetric hydraulic drive units under operating conditions and suggesting ways to increase its durability. It was established that to increase the wear resistance of a resolving compound and the durability of the volumetric hydraulic drive aggregates, it is necessary to ensure that in distribution pairs the maximum bearing capacity is greater than the maximum long-term operating load in these connections. To solve this problem, it is proposed to create coatings with high tribotechnical properties by the method of electricspark machining. Keywords: resource-limiting compound, volumetric hydraulic drive, modeling, finite element method, bearing capacity, operating load, wear resistance, electrospark machining For citation: Ionov P. A., Senin P. V., Stolyarov A. V. Modeling of Stress-Strain State in Connection Resource Defines of Volumetric Hydraulic Drive. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):537–551. DOI: https://doi.org/10.15507/0236-2910.028.201804.537-551 Acknowledgements: The study was conducted with the financial support of the Ministry of Education and Science of the Russian Federation (state task, direction: development of competencies) project № 11.3416.2017/4.6 “Development of technologies and tools to improve the durability of parts, assemblies, machines and equipment by creating nanostructured coatings sources of concentrated energy”.

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Evdokimov, Alexey Petrovich. "INITIAL AND RESIDUAL RESOURCE OF RUBBER-CORD SHELLS OF CONNECTING DEVICES OF ROLLING STOCK." Globus: technical sciences 7, no. 2(38) (May 19, 2021): 25–30. http://dx.doi.org/10.52013/2713-3079-38-2-3.

Повний текст джерела

Анотація:

In article the basic settlement dependences of a resource rubber-cord environments are given on the basis of the received results of experimental researches of integrated characteristics in view of quasi-elastic, not elastic and total deformation. Diagrams of dependence of durability of environments from a corner of a twisting and the specified kinds of deformation are constructed.

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Zhang, Peng, Yonghui Yang, Juan Wang, Shaowei Hu, Meiju Jiao, and Yifeng Ling. "Mechanical Properties and Durability of Polypropylene and Steel Fiber-Reinforced Recycled Aggregates Concrete (FRRAC): A Review." Sustainability 12, no. 22 (November 15, 2020): 9509. http://dx.doi.org/10.3390/su12229509.

Повний текст джерела

Анотація:

With the development of concrete engineering, a large amount of construction, demolition, excavation waste (CDEW) has been produced. The treated CDEW can be used as recycled aggregate to replace natural aggregate, which can not only reduce environmental pollution and construction-related resource waste caused by CDEW, but also save natural resources. However, the mechanical properties and durability of Recycled Aggregates Concrete (RAC) are generally worse than that of ordinary concrete. Various fiber or mineral materials are usually used in RAC to improve the mechanical properties and durability of the matrix. In RAC, polypropylene (PP) fiber and steel fiber (SF) are two kinds most commonly used fiber materials, which can enhance the strength and toughness of RAC and compensate the defects of RAC to some extent. In this paper, the literature on PP fiber- and SF-reinforced RAC (FRRAC) is reviewed, with a focus on the consistence, mechanical performance (compressive strength, tensile strength, stress–strain relationship, elastic modulus, and shear strength), durability (water absorption, chloride permeability, carbonation, freeze–thaw cycling, and shrinkage), and microstructure. The research findings regarding FRRAC were analyzed and compared. The results showed that adding mineral additives and fiber in RAC had a good synergistic effect, which made FRRAC have good mechanical properties, high durability and high temperature resistance, and several application prospects. The information and summary presented in this paper exhibit new knowledge and information on the application of FRRAC.

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Matviychuk, Viktor, and Oleg Gaidamak. "INCREASING THE DURABILITY OF DETAILS TO WORK UNDER REPEATABLE LOADS." Vibrations in engineering and technology, no. 3(98) (October 30, 2020): 15–24. http://dx.doi.org/10.37128/2306-8744-2020-3-2.

Повний текст джерела

Анотація:

The article presents the results of the development of processes to improve the performance of parts operating under repeated variable loads, taking into account the reasonable parameters of surface plastic deformation (SPD) and cold gas-dynamic spraying of coatings. The influence on the parameters of the working surface layer, the nature of the distribution of the stress-strain state of the surface layer of material and residual compressive stresses, as well as the values of the used resource of plasticity of the surface layer of the workpiece, the parameters of the SPD process. The article shows that the main factor in the formation of residual compressive stresses during SPD is the decrease in the density of the surface layer of the workpiece, which is associated with the use of the plasticity resource. The model of calculation of the used resource of plasticity of material of preparation at SPD which allows to provide the improved quality of a surface layer of details is offered. A method of moving the workpiece layers with maximum hardening and residual compression stresses to the surface of the part by applying a deforming tool of reduced size in the following passes with coating the surface of the part with gas-dynamic spraying before SPD. Cold gas-dynamic coating by spraying, in contrast to most known gas-thermal coating methods that take place under significant temperature effects on the surface of the part, which is unacceptable for surfaces treated by SPD methods, provides a permissible temperature regime for creating special auxiliary coatings while preserving surface properties SPD. The technology of gas-dynamic coating by spraying includes heating the compressed gas (air), directing it into the nozzle and forming in this nozzle supersonic air-powder flow, sprayed material (copper, aluminum), acceleration of this powder material to supersonic speeds and directing it to the surface of the processed product. As a result, a special auxiliary coating (copper or aluminum) is formed on the surface of the product, which improves the parameters of the SPD process.

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Burumkulov, F. Kh, P. A. Ionov, D. A. Galin та A. M. Zemskov. "Ways to increase the durability of ГСТ-90 volumetric fluid power drive". Traktory i sel hozmashiny 79, № 10 (15 жовтня 2012): 39–42. http://dx.doi.org/10.17816/0321-4443-66004.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Gromov, V. I., N. A. Yakusheva, A. V. Vostrikov, and N. N. Cherkashneva. "HIGH STRENGTH STRUCTURAL STEELS FOR GAS-TURBINE ENGINE SHAFTS (review)." Aviation Materials and Technologies, no. 1 (2021): 3–12. http://dx.doi.org/10.18577/2713-0193-2021-0-1-3-12.

Повний текст джерела

Анотація:

The motor shaft of a gas turbine engine, being a highly loaded part of a particularly critical purpose, has increased requirements for maintaining the level of properties during long-term operation, ensuring the structural strength of the product. An increase in the resource and durability of the product is achieved due to the development of new materials that surpass the used domestic and foreign analogues in their mechanical characteristics. FSUE «VIAM» has deve-loped high-strength structural steels with enhanced characteristics of strength, toughness, durability and heat resistance.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Baglioni, Elena, and Liam Campling. "Natural resource industries as global value chains: Frontiers, fetishism, labour and the state." Environment and Planning A: Economy and Space 49, no. 11 (August 31, 2017): 2437–56. http://dx.doi.org/10.1177/0308518x17728517.

Повний текст джерела

Анотація:

Despite 30 years of research on global value chains, the appropriation of nature in general and natural resource industries in particular remain marginal both theoretically and empirically. There is a parallel ecological deficit in labour process theory and a lack of applied research on natural resource industries. But since historical capitalism is based on the expanding appropriation and transformation of nature by labour, these lacunae must be redressed. Contributing to an emerging body of work in environmental economic geography and the international political economy of the environment, this article theorises global value chains through the lens of the circuit of capital as a tool to unravel some distinctive features of natural resources industries. We propose a framework for the study of natural resource industries as global value chains based on five propositions: (a) commodity frontier theory, (b) the fetishism of natural resources, (c) the socio-ecological indeterminacy of the labour process, (d) distance and durability in the production of time and (e) the contingency of the capitalist state in (re)producing global value chains. While far from exhaustive, we argue that this original synthetic framework provides crucial bases for a research agenda on global value chains in natural resources.

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Kolchunov, Vitaly, Natalia Androsova, and Tatyana Kolchina. "Crack Resistance Criteria for Reinforced Concrete Beams with Corrosion Damage in Strength Resource Assessment." Applied Mechanics and Materials 725-726 (January 2015): 740–45. http://dx.doi.org/10.4028/www.scientific.net/amm.725-726.740.

Повний текст джерела

Анотація:

In the framework of ultimate state calculation methods the paper presents some propositions for stress-strain state, crack resistance analysis and failure state of reinforced concrete structures with corrosion damage at supports. The work concerns the durability of concrete and reinforced concrete elements with corrosion damage. The theory for reinforced concrete with corrosion damage is presented for plane stress state

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Rumb, V. K. "Effect of the initial deflection on the strength and durability of the ship's marquee." Transactions of the Krylov State Research Centre S-I, no. 1 (December 8, 2021): 92–93. http://dx.doi.org/10.24937/2542-2324-2021-1-s-i-92-93.

Повний текст джерела

Анотація:

The theoretical provisions of the calculation of the strength and durability of the shuttle with the initial bend are set out. The concrete example shows the significant impact of the deflection on the strength and resource indicators of the ship's cvds.

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Jordana, Xavier, Nekane Marín-Moratalla, Daniel DeMiguel, Thomas M. Kaiser, and Meike Köhler. "Evidence of correlated evolution of hypsodonty and exceptional longevity in endemic insular mammals." Proceedings of the Royal Society B: Biological Sciences 279, no. 1741 (April 25, 2012): 3339–46. http://dx.doi.org/10.1098/rspb.2012.0689.

Повний текст джерела

Анотація:

Here, we test whether the increase in tooth height in insular endemics results from the expansion of the dietary niche under resource limitation, as widely considered, or whether it represents an investment in dental durability in response to the selection for extended longevity under low levels of extrinsic mortality. We tested these hypotheses in the extremely hypsodont fossil bovid Myotragus balearicus from the Balearic Islands, an ideal model to study the evolutionary trends on islands. Dental abrasion was significantly lower in the insular bovid than in highly hypsodont continental artiodactyls, suggesting that feeding habits are not the sole driving force behind increased crown height. However, the estimated longevity for M. balearicus based on dental durability was two times that predicted from body mass. Survivorship curves confirm that an extraordinarily large number of individuals approached the longevity of the species. Our results, hence, provide evidence that hypsodonty in insular endemics is the outcome of selection for increased durability of the permanent dentition in association with an extended lifespan. In the context of insularity, our results lend additional support to the disposable soma theory of ageing confirming the dependency of somatic maintenance and repair on lifespan, and its control by resource availability and extrinsic mortality.

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Дудников, Анатолий Андреевич, Александра Ивановна Беловод, Андрей Григорьевич Пасюта, Антон Александрович Келемеш, and Александр Викторович Горбенко. "Technological methods of increasing the durability and resource of working parts of tillage machines." Technology audit and production reserves 5, no. 1(25) (September 22, 2015): 4. http://dx.doi.org/10.15587/2312-8372.2015.48825.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Zaydes, Semen, Artem Mashukov, and Aleksei Tatarinov. "ESTIMATION OF HIGH-PRESSURE VALVE ISOLATION STATION DURABILITY AND RESOURCE BY HARDNESS MEASUREMENT RESULTS." Proceedings of Irkutsk State Technical University 112, no. 5 (May 2016): 37–44. http://dx.doi.org/10.21285/1814-3520-2016-5-37-44.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Gurko, Anna. "Formation of the resource saving process in commercial property buildings during the introduction of “green” standards in Russia." E3S Web of Conferences 135 (2019): 03004. http://dx.doi.org/10.1051/e3sconf/201913503004.

Повний текст джерела

Анотація:

The article is dedicated to one of the most essential areas in the construction industry: consideration of the issues related to resource saving, ecologically and economically rational use of natural resources in accordance with “green standards” of the commercial property buildings, offices, in particular. During the operation of office buildings there takes place negative impact on all the components of the environment. Herewith, the first issues considered by the operating organizations are the cost of the facility, safety of technological processes, reliability, durability and operational characteristics, and only then the issues of building environmental friendliness and energy efficiency, the consequences of which are irrational use of natural resources and accumulation of environmental damage. The number of existing systems certifying “green” buildings is insufficient to create a stable human environment. Formation of the resource saving mechanism during the operation of office buildings requires the application of the “green” standards criteria, making it possible to provide results of the stable approaches during the entire operational lifetime of the building. Based on the local and foreign experience in resource saving stimulation under the “green standards” the article provides the estimation criteria making it possible to implement the ecological and economic evaluation of the resource saving mechanism during the operation of office buildings.

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Thapliyal, Nitin, and Priti Dimri. "Load Balancing in Cloud Computing Based on Honey Bee Foraging Behavior and Load Balance Min-Min Scheduling Algorithm." International Journal of Electrical and Electronics Research 10, no. 1 (March 30, 2022): 1–6. http://dx.doi.org/10.37391/ijeer.100101.

Повний текст джерела

Анотація:

Cloud computing relies on the collection and distribution of services from internet-based data centers. With the large resource pool available in internet wide range of users are accessing the cloud. Load balance is important feature involving resource allocation to prevent overloading of any system or optimal use of resources. Major load in cloud network are concerned with CPU, memory and network. This cloud computing aspect has not yet earned too much coverage. Although load balancing is an important feature for cloud computing, concurrent computing etc. In these areas, several algorithms were suggested to solve load balance problem. However, it does recommend very few cloud computing algorithms. Given that cloud storage differs considerably from all other environments, particular load balancing algorithm should will built in sort to serve its needs. This work proposes novel load-balancing algorithm based on artificial bee colony algorithm and load balancing min-min scheduling algorithm for balancing load in cloud computing network. Simulation here is carried out in clouds to generate comparative results. Improving on various parameters like power consumption, resource utilization, stability of system are some major areas focused on. This work has used algorithm that has the best efficiency of resources, optimal performance, minimal response time, scalability and durability in integrated resource planning.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Gu, Xiaowei, Ziyang Hu, Peng Liu, Shuyun Pang, and Haofeng Chi. "Research progress of key technologies for preparing concrete admixtures by multiple activation of iron-containing tailings." E3S Web of Conferences 198 (2020): 03002. http://dx.doi.org/10.1051/e3sconf/202019803002.

Повний текст джерела

Анотація:

Iron tailings are an excellent secondary resource. Reasonable use, it can not only alleviate the problem of resource shortage, but also solve some environmental pollution problems. Therefore, it has a good development prospect. The resource utilization of iron tailings has always been a hot spot of social concern. The article reviews the results achieved by the predecessors. In addition, outlines the method of activation of iron tailings and the influence of its strength and durability as a concrete composite admixture. At last, the prospects of the research on the utilization of iron tailings are put forward.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Salamakhin, Pavel M., and Evgeny A. Lugovtsev. "Theoretical foundations for calculating bridges for endurance using the kinetic theory of durability of structural materials." Structural Mechanics of Engineering Constructions and Buildings 17, no. 3 (October 24, 2021): 219–27. http://dx.doi.org/10.22363/1815-5235-2021-17-3-219-227.

Повний текст джерела

Анотація:

The economically effective method for determining the unknown parameters of the dependence of the durability of structural materials on the level of acting constant stresses in them and their absolute temperature for various structural materials is proposed, taking into account the data established by Academician of the USSR Academy of Sciences S.N. Zhurkov. It does not require long-term testing of materials, but is based on the use of the results of short-term standard machine failure of two groups of standard samples of materials at two significantly different temperatures. When using these parameters and the Bailey integral criterion for summing up the losses in the durability of materials, it is possible to calculate the endurance of elements of road bridge structures from any structural materials and to determine the residual durability resource of the structure under the predicted subsequent mode of loading it with real temporary vertical loads.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Hudeček, Pavel, and Petr Dostál. "Analysis of Properties of Hard Coatings and Wear Resistance of Chemical Vapour Deposition (PVD) Coated Technology." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 63, no. 5 (2015): 1477–83. http://dx.doi.org/10.11118/actaun201563051477.

Повний текст джерела

Анотація:

Modern coating methods are having become an important part of industry. Wear resistance, durability, toughness (breakage resistance) and hot hardness (high hardness and chemical stability at high temperature) are the four main technological properties necessary for durability and long life time. These proprieties are for productivity, economy and ecology very important point. This resource deals with the analysis of properties of hard coatings and wear resistance of chemical vapour deposition (PVD) coated technology. It focuses on the preparation, execution and evaluation of test coatings on the front ball-milling cutters. Examination of these characteristic properties may give into an insight to the reason why some systems show excellent wear characteristic.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Matviychuk, Viktor, and Oleg Gaidamak. "INCREASING OF THE DURABILITY OF DETAILS WORKING UNDER REPEATABLE- LOADS." Vibrations in engineering and technology, no. 1(96) (August 27, 2020): 5–14. http://dx.doi.org/10.37128/2306-8744-2020-1-1.

Повний текст джерела

Анотація:

The article develops processes of increase the durability of parts operating under repeated loads, by justifying the parameters of surface plastic deformation (SPD) and cold gas-dynamic coating. The influence on the depth of the reinforced surface layer, the nature of the distribution of the stress-strain state of the material and residual compressive stresses, as well as the value of the used plasticity of the metal, the parameters of the SPD process. The hypothesis is substantiated that the main factor in the formation of residual compressive stresses during SPD is the decrease in metal density, which is associated with the use of the plasticity resource. The model of definition of the used resource of plasticity of metals at SPD is developed, that allows to provide qualitative characteristics of a surface layer of details. Methods for shifting the layer with maximum hardening and residual compressive stresses to the surface of the part by using a deformable tool of smaller dimensions in subsequent passes and gas-dynamic coating before SPD. The vast majority of traditional gas-thermal coating methods occur at significant temperature effects on the surface of the part, which is unacceptable for the surface treated by SPD methods. Cold gas-dynamic spraying provides an allowable temperature regime for the creation of special auxiliary coatings while maintaining the properties of the surface treated by SPD methods. The technology of gas-dynamic coating includes heating the compressed gas (air), feeding it into the nozzle and forming a supersonic air stream in this nozzle, introducing a powder material into this stream, accelerating this material in the nozzle by a supersonic air flow and directing it to the surface of the workpiece. As a result, a special auxiliary coating is formed on the surface of the product, which provides optimal parameters of the SPD process.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Deissmann, G., S. Neumeier, G. Modolo, and D. Bosbach. "Durability of potential plutonium wasteforms under repository conditions." Mineralogical Magazine 76, no. 8 (December 2012): 2911–18. http://dx.doi.org/10.1180/minmag.2012.076.8.06.

Повний текст джерела

Анотація:

AbstractSeparated stocks of UK civil plutonium are currently held as a zero value asset in storage, as there is no final decision about whether they should be treated as a resource for future use as nuclear fuel or as waste. Irrespective of future UK government strategies regarding plutonium, at least a portion of the UK civil plutonium inventory will be designated for geological disposal. In this context, we performed a high-level review of the performance of potential wasteforms for the disposal of separated civil plutonium. The key issues considered were the durability and chemical reactivity of the wasteforms in aqueous environments and the long-term radionuclide release under conditions relevant to geological disposal. The major findings of the review, relevant not only to the situation in the UK but to plutonium disposal in general, are summarized in this paper. The review showed that, in the event of a decision being taken to declare plutonium as a waste for disposal, more systematic studies would be required to constrain the wasteform performance under repository conditions in order to derive realistic source terms for a safety case.

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Altschul, Jeffrey H. "The Society for American Archaeology’s Task Forces on Landscape Policy Issues." Advances in Archaeological Practice 4, no. 2 (May 2016): 102–5. http://dx.doi.org/10.7183/2326-3768.4.2.102.

Повний текст джерела

Анотація:

AbstractThe management of cultural resources by federal land-managing agencies in the United States is moving in the direction of programmatic approaches that consider archaeological resources on a regional or landscape level. In 2014, the Society for American Archaeology (SAA), in response to meetings with federal agencies, established three task forces on issues related to landscape-scale cultural resource management (CRM). The task forces focused on: (1) survey data quality, durability, and use; (2) incorporating archaeological resources in regional land-use plans; and (3) valuing archaeological resources. Revised reports of the task forces are being published in this issue of Advances in Archaeological Practice. This paper provides the context and history of the task forces, particularly the CRM challenges facing federal land-managing agencies leading to the selection of topics that are subjects of the published articles.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Subhan, Muhammad, and Ahmad Bashawir Abdul Ghani. "Analyzing Growth Opportunity of Port from the Resource-based Perspective The Case of Port of Tanjung Pelepas Malaysia." Gadjah Mada International Journal of Business 10, no. 3 (September 12, 2008): 353. http://dx.doi.org/10.22146/gamaijb.5557.

Повний текст джерела

Анотація:

Capturing growth opportunity has become a major integral activity of any port to sustain growth and competitive advantage. One of the famous strategies in leveraging sustainable growth and competitive advantage is the resource-based theory application into port strategic management, viewing resources of the port (internal and external) and its capabilities as the sources for achieving competitive advantage. In this study, we attempt to identify, exploit, and analyze growth opportunity of a Malaysian port from the perspective of the theory. We analyze the port’s resources in terms of values, uniqueness, inimitability, durability, and substitutability. The result is then compared with its rival ports in the region. This study recognizes that the port has successfully identified and exploited its resources for capturing growth opportunity and competing with other ports in the region. We perceive that the port will sustain its growth and competitive advantage as a major port in the region based on its current performance and rivalry circumstances. This study signifies that the higher the level to which resource-based theory of competitive advantage is applied, the higher and longer the growth and competitive advantage will be achieved by the port.

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Šnīdere, Laimdota, Ineta Geipele, and Iveta Stāmure. "Case Study of Standard Multi-Storey Residential Building Owners and Tenants’ Perception of Building Technical Conditions and Renovation Issues." Baltic Journal of Real Estate Economics and Construction Management 5, no. 1 (November 27, 2017): 6–22. http://dx.doi.org/10.1515/bjreecm-2017-0002.

Повний текст джерела

Анотація:

Abstract The majority of residents in Latvia live in standard multi-storey residential buildings, which were constructed between 1950 and 1992. At present, these buildings are obsolete; besides, in the course of construction process the durability and reliability levels were planned to be insufficient. In Riga, residents of standard multi-storey residential buildings do not support building renovation and are passive, despite the availability of the EU and government support as well as co-financing of building renovation projects. The majority of the respondents assume that the apartment is the most significant asset of the family. Moreover, 34 % - 69 % of the participants have renovated their apartment and save resources within their apartment boundaries. Only some respondents evaluate the technical condition of communal property, but most respondents do not have information concerning resource supply and energy accounting as well as are not interested in resource saving possibilities within the building in general, and do not understand the importance of technical maintenance of the building.

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Rimshin, Vladimir, Ekaterina Kuzina, and Alexey Neverov. "Residual resource of force resistance to deformation." E3S Web of Conferences 135 (2019): 01069. http://dx.doi.org/10.1051/e3sconf/201913501069.

Повний текст джерела

Анотація:

The problem of the durability of reinforced concrete structures of urban engineering structures is currently one of the urgent problems in modern construction due to the continuously growing volume of expensive repair and restoration work, facilities reconstruction, a tendency to a general decrease in quality requirements, and the scale of reinforced concrete structures application in difficult climatic conditions. The theoretical foundations of calculating the residual life of the force resistance to transverse bending with the strength of normal sections in the article, algorithms for calculating the residual life of the force resistance and reinforcement of corrosion-damaged reinforced concrete structures are defined. A complex calculation method is considered in this article that allows to quantitatively assessing the state and resources of crack resistance of reinforced concrete structures damaged by corrosion, to calculate the necessary levels of compression and loss of tension, as well as the exposure to preserve crack resistance in time at specific loading levels and intensities of corrosion effects. The developed complex calculation method can be presented as part of the solution to the problem of preventing and eliminating emergency situations. The theoretical basis for calculating the residual resource of strength resistance to transverse bending by the strength of inclined sections are discussed in the article, the calculation algorithms are studied, and examples are given.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Letkiewicz, Andrzej, and Michał Suchanek. "SYSTEMIC CONDITIONS OF EFFICIENCY AND DURABILITY OF ROAD TRANSPORT ENTERPRISES." Zeszyty Naukowe Uniwersytetu Gdańskiego. Ekonomika Transportu i Logistyka 73 (February 2, 2018): 69–78. http://dx.doi.org/10.5604/01.3001.0010.8304.

Повний текст джерела

Анотація:

The basic condition for the proper configuration of inputs and outputs in a transport company is the ability to optimise, build, and implement a strategy based on carefully selected components of the information and decision-making system, capable of taking into account the different optimisation criteria for each level and of gathering and generating information useful in the process of developing a strategy. Within this system, IT tools that increase the efficiency of the technical dimension of decision-making processes are useful. For Polish road transport companies, economically speaking, the basic input and output record-keeping systems are accounting systems, used by nearly 89% of the surveyed entities. In the operational context, 58% of the entities declare using resource management systems. Nearly 18% of the companies possess a formal strategy.

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Poberezhny, L., S. Tregubenko, L. Poberezhna, A. Hrytsanchuk, and A. Stanetsky. "Influence of loads in the process of laying on the resource of sea pipelines." Archives of Materials Science and Engineering 2, no. 96 (April 1, 2019): 63–72. http://dx.doi.org/10.5604/01.3001.0013.2385.

Повний текст джерела

Анотація:

Purpose: In the process of laying on the bottom of the sea material of the pipeline undergoes single-cycle alternating load. The purpose of the work is to determine the effect of pre-operational loads on the resource of marine pipelines. Design/methodology/approach: The influence of the method of construction of pipelines on their stress-strain state is analysed. According to the real modes of packing of sea pipelines, the loading regime is programmed and the laboratory modelling of the pipe- laying process by the S-method has been programmed. Findings: According to the results of one-cycle shift load were obtained characteristics of the hysteresis loop. It is proposed to simplify the mathematical description of the hysteresis loop of the pipeline laying cycle in the given form. It was shown that the preload during the construction process negatively affects the durability of the pipeline material due to the exhaustion of its plasticity resource, reducing it to 70%. Research limitations/implications: In the future, investigations into the effect of overloading and overloading during the repair of pipeline sections on their durability and on the safe exploitation of resources should be continued. Practical implications: The developed method of estimation of influence of pre- operational loads in the process of pipeline laying on its safe exploitation resource is used in gas-extraction enterprises. Originality/value: To forecast the deformation behaviour of the pipeline material in the laying cycle, it is efficient to use diagrams of a sign-changing single-cycle bend, which were built considering the creep. The fatigue life capability of a steel pipeline depends on the history of the pipeline load in the laying cycle. Ratio σ*0.2c / σ*0.2t and ε yc / ε yt can use as power and deformation criteria for evaluating Bauschinger effect. It is suggested that fatigue damage is determined by the width of the hysteresis loop.

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Mironov, Denis A. "Technological Methods of Increasing the Resource and Efficiency of Fast-Wearing Working Bodies." Elektrotekhnologii i elektrooborudovanie v APK 48, no. 4 (December 2021): 118–23. http://dx.doi.org/10.22314/2658-4859-2021-68-4-118-123.

Повний текст джерела

Анотація:

The working bodies of tillage machines are operated in a soil abrasive environment and, due to wear, they change their shapes and sizes, which negatively affects tillage agrotechnical and energy indicators. The problem of increasing the durability and operability of the working bodies of tillage machines remains relevant. In particular, this is reflected in the reduced resource of serial tillage working bodies. (Research purpose) The research purpose is to ensure the increased durability and efficiency of agricultural machines. (Materials and methods) The downtime of agricultural machinery due to the failure of tillage working bodies negatively affect the efficiency of agricultural operations and entail up to 15-20 percent reduction in subsequent yields. The cost of purchasing and reinstalling spare parts is up to 18 percent in the structure of the cost of agricultural products. The most technological method of plasma-powder surfacing (hardening) has been used, which is up to two times more productive and 2.2-2.7 times more economical in comparison with the known technology of plasma surfacing in argon medium. The most high-strength (σВ at least 1600 megapascals) steels of the type 25XGTYUR, 30XGSA, 27XGR were selected for the manufacture of the developed tillage working bodies. (Results and discussion) Parts made of high-quality materials according to the created technology are not inferior in resource and wear resistance to the best foreign surfaced analogues, and non-melted imported products are 1.5-1.7 times superior. New materials and technological surfacing methods for strengthening domestic and import-substituting working bodies of agricultural machines allow, in terms of resource and operational indicators, to achieve a level of competitiveness with leading foreign manufacturers. (Conclusions) According to the «quality-price» criterion, new working bodies with reasonable materials, structural and technological parameters have a 1.5-2.5 times advantage over the best foreign analogues.

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Sheleg, V. K., D. G. Shaturov, and G. F. Shaturov. "ANALYSIS AND SELECTION OF RATIONAL CUTTING MODES WHILE USING HARD-ALLOY TOOL FOR SHAFT TURNING." Science & Technique 17, no. 1 (February 9, 2018): 14–20. http://dx.doi.org/10.21122/2227-1031-2018-17-1-14-20.

Повний текст джерела

Анотація:

Turning machining of such parts as shafts is considered as the most widely-spread method formanufacturing units, mechanisms and machinery. While doing so it is necessary to ensure high quality of shaft turning with the help of a hard-alloy tool (accuracy and roughness, stability and predictability of steel edge dimensional wear), maximum tool durability, resource of its service life and productivity. As it is known all these operational parameters of the tool depend very heavily on cutting speed. However absence of an analytical dependence for determination of optimum cutting speed value does not per permit to prescribe optimum operational modes at the stage of technology design process. The cutting tool can be subjected to mechanical, anrasive, adhesive, oxidation (chemical), thermal-fatigue and diffusion wear types depending on turning conditions. In this case wearing process consists of two wear types and one of them influences at a certain point on wearing process to a greater extent than the other one. Methodology for prescription of rational turning modes for medium and high cutting speeds ensuring maximum resource of the tool operation has been developed in the paper and it has been based on the analysis of the existing viewpoints about changes in the hard-alloy tool durability due to cutting speed while turning shafts. The range of cutting speed changes has been determined in the paper and it leads to an increase of the tool durability period and, correspondingly, turning productivity of 45 steel grade shafts while using the tool with T15K6-hard-alloy replaceable inserts.

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Vorobchuk, Vasily, Maria Matveeva, and Artem Peshkov. "Decorative concrete on white cement: resource provision, technology, properties and cost-effectiveness." MATEC Web of Conferences 212 (2018): 01023. http://dx.doi.org/10.1051/matecconf/201821201023.

Повний текст джерела

Анотація:

Decorative concrete refers to a special kind of concrete. Products made of decorative concrete must meet, in addition to the increased requirements for appearance, certain architectural expressiveness and also certain indicators for strength, durability, and environmental friendliness. In addition, one should strive to reduce the cost of both decorative concrete and products made of such concrete. The analysis is carried out, experimental researches of qualitative indicators of industrial man-caused wastes are also studied: carbide lime, fluoride, sludge-lignin, their material and chemical composition. The possibility of using the analyzed industrial wastes as raw materials for production of white and color cements is established. The physicomechanical properties of the obtained cements and decorative concretes on their basis are studied, the economic efficiency of the proposed technology is determined.

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Pavlu, Tereza, Jiří Pazderka, Kristina Fořtová, Jakub Řepka, Diana Mariaková, and Tomáš Vlach. "The Structural Use of Recycled Aggregate Concrete for Renovation of Massive External Walls of Czech Fortification." Buildings 12, no. 5 (May 18, 2022): 671. http://dx.doi.org/10.3390/buildings12050671.

Повний текст джерела

Анотація:

The use of recycled aggregate concrete is mainly negatively affected by its poorer mechanical and long-term properties. However, there are few structural applications for which recycled aggregates can be used. In this case study, the possibility of use as massive external reinforcement wall is verified. For this structural application, the most important characteristics are freeze–thaw resistance, and carbonation resistance and then the mechanical properties such as compressive strength. Durability characteristics of the materials have been tested and improved in the study. The mechanical properties and durability of recycled aggregated concrete have been verified and crystalline mixture has been used to improve durability. The specific structural application of the massive external reinforcement wall is for the renovation of the Czech WW2 concrete fortification, which is one of the most important cultural heritages of the Czech Republic of the 20th century. However, these buildings have not yet been professionally rebuilt, but this research project aims to change this trend. The thickness of the bunker wall is between 0.5 and 3.5 m (depending on the type of bunker) which leads to a huge amount of concrete and primary resources consumption; however, the security function is not necessary today, so the reconstruction could be provided by recycled aggregate concrete. The results showed a positive effect of the crystalline mixture on the essential properties of recycled aggregate concrete. Recycled aggregate concrete with a complete replacement of aggregate by recycled concrete or masonry aggregate is possible to use for the reconstruction of the Czech WW2 concrete fortification and save natural aggregate as a primary resource.

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Mezhetskiy, G. D., and V. A. Strelnikov. "INCREASING THE RESOURCE OF DIESEL CYLINDER HEADS BY IMPROVING THE TECHNOLOGY OF THEIR RESTORATION." Scientific Life 15, no. 7 (July 31, 2020): 950–57. http://dx.doi.org/10.35679/1991-9476-2020-15-7-950-957.

Повний текст джерела

Анотація:

The article presents the results of studies of the thermal fatigue strength of diesel cylinder heads and their resource under operating conditions, by using the most advanced technology for their restoration. Based on the results of theoretical calculations of durability and operational studies, a restoration technology has been proposed, which makes it possible to increase the resource of cylinder heads by 2 ÷ 2.5 times. For this purpose, the non-uniformity of the temperature field on the firing bottom of the cylinder heads of YaMZ-238NB diesel engines was theoretically determined and experimentally confirmed. On the basis of theoretical calculations, the most heatstressed sections of the plane of the cylinder heads of diesel engines bonded to the cylinder block were determined, and the appearance of cracks in them. When developing a method for calculating the temperature fields of the fire bottom, the universal finite element method (FEM) was used. This method makes it possible to take into account the geometry and conditions of thermal loading of the cylinder heads quite accurately. For the determination of temperature fields, a well-founded assignment of the boundary conditions is crucial. With this in mind, a number of surfaces were determined that characterize the durability of the entire part during operation. As a result of calculations carried out on a computer, temperature fields have been obtained that make it possible to analyze the distribution of temperatures and temperature gradients at any point of the fire bottom. The highest temperatures (620...635K) are localized in the central part of the fire bottom, which is two times higher in thermal intensity than the peripheral one and confirms the appearance of cracks in these places during the operation of diesel cylinder heads.

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Trukhanska, Olena. "TECHNOLOGICAL METHODS OF INCREASING WEAR RESISTANCE AND DURABILITY OF DETAILS." ENGINEERING, ENERGY, TRANSPORT AIC, no. 4(111) (December 18, 2020): 109–15. http://dx.doi.org/10.37128/2520-6168-2020-4-12.

Повний текст джерела

Анотація:

Improving the reliability and service life of machines, components, units is an important factor in reducing the cost of restoration, downtime of equipment in repair, reducing the number of spare parts. The introduction of the latest technologies of agricultural production, as well as constant modern improvement, the complexity of agricultural machinery is a natural result of its development. Parts restoration technologies are among the most resource-saving, because compared to the manufacture of new parts costs are reduced by up to 70%. The main source of resource savings is the cost of materials. At longtime use of machines wear of details is followed by decrease in operational indicators, causes deterioration of quality of products. The tractor PTO shaft is subjected to significant static and dynamic loads. The high wear rate is due to constant friction with the grafting disc, gear, inner bearing rings. The production of a new power take-off shaft requires significant costs, so the development of new technological processes of repair and restoration is relevant. It is rational at restoration of the previous sizes and return of a detail of normal mechanical properties. The remanufactured part is consuming its life, like a new part, and may exceed the service life of the new part. With the increase in the equipment of agricultural production with more advanced equipment, the conduct of complex mechanization and increasing the efficiency of the use of equipment, repair production is developing and changing. The development of the field of restoration of worn parts is based on close cooperation of repair production with branch and basic science, and achievement of scientific and technical progress. A promising direction of restoration technology in the organizational plan is the deepening of the method of group restoration technology - the creation of a unified group equipment for the restoration of surfaces. It is established that the majority of details of the restored cars are rejected at the expense of insignificant wear of working surfaces, making no more than 1% of initial weight of details. Experiments and practice show that the repair of agricultural machinery is technically impossible to avoid. Most worn parts have a high residual value: their restoration consumes 20-30 times less metal and materials than the manufacture of new ones, which is economically feasible. Problems are considered: the choice of technological process of restoration, the choice of technological equipment, tools.

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Bernhard, William, and David Leblang. "Political Parties and Monetary Commitments." International Organization 56, no. 4 (2002): 803–30. http://dx.doi.org/10.1162/002081802760403784.

Повний текст джерела

Анотація:

Increased levels of economic openness in the industrial democracies have heightened the potential for intra-party and intra-coalition policy conflicts, hurting the ability of parties to win and retain office. We argue that politicians can use monetary commitments to help manage these conflicts and improve cabinet durability. To determine the political value of these commitments, we test the effect of fixed exchange rates and central bank independence on cabinet durability using a set of 193 cabinets in sixteen parliamentary democracies across the period 1972–98. The results indicate that monetary commitments are associated with higher cabinet durability, particularly for coalition governments. We then use the results of our statistical models to generate expected cabinet durability under alternative institutional configurations. By comparing these expected values, we show that actual monetary reforms in the industrial democracies have helped (or at least not hurt) the ability of political parties to remain in office.

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Neumann, Julia, and Rolf Breitenbücher. "Thin concrete overlays wit carbon reinforcement on deteriorated concrete pavements." Acta Polytechnica CTU Proceedings 33 (March 3, 2022): 404–10. http://dx.doi.org/10.14311/app.2022.33.0404.

Повний текст джерела

Анотація:

In many countries, concrete pavements are normally built as Jointed Plain Concrete Pavements. Due to a lack of alternatives, repairing deteriorated concrete pavements usually requires the replacement of the complete pavement structure and maintaining the joints, which is labour- and resource-intensive. To increase the durability of repairs and to save resources concrete overlays with carbon reinforcement are developed. By the application of non-corrosive carbon-textile reinforcement cracks might be distributed so fine, that such an overlay can be executed jointless, unlike in previous repair methods. For a durable repair the bond behaviour between the retained concrete and the overlay as well as between the overlay-concrete and the textile reinforcement have to be considered. In this paper, the basic principles and feasibility of such a repair method are examined. On the one hand, the decisive influencing variables and parameters such as bond behaviour and cracking behaviour within the overlay are pointed out and discussed. On the other hand, the performed special lab tests will be presented. These tests include cyclic loadings on large-scale beams with integrated overlays of such types, evaluating the bond behaviour and the durability after a few millions of load cycles. Furthermore, the crack formation in the overlay is determined by means of tensile and flexural tensile strength tests.

Стилі APA, Harvard, Vancouver, ISO та ін.

Статті в журналах з теми "Resource durability"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями