EXCAVATOR WORKING EQUIPMENT FOR ISLANDS OF PIPELINE REPAIR

2021 ◽  
Vol 2021 (11) ◽  
pp. 66-72
Author(s):  
Anton Letopol'skiy ◽  
Pavel Korchagin ◽  
Irina Teterina
Keyword(s):  
Hydraulic System ◽  
Main Idea ◽  
Road Construction ◽  
Size Group ◽  
Theoretical Studies ◽  
Repair Work ◽  
The Third ◽  
Excavator Bucket ◽  
The Stability ◽  
The Cost

Work objective. Modernization of the excavator's working equipment design intended for islands of pipeline repair together with confirmation of its operability by checking the machine for stability, carrying out the necessary calculations of the hydraulic system. Methods. The main idea is in accessorizing the main working equipment of the excavator with a structure consisting of three teeth, which is in a body with an excavator bucket form a pickup mechanism. To confirm the operability of the proposed design, theoretical studies have been carried out aimed at determining the stability of the machine for the most dangerous design operating positions, and permissible pipe sizes have been established so that working with these sizes provides the stability of the machine. Results. A variant of improving the design of the excavator working equipment of the third size group has been developed. The equipment is intended for carrying out random repair of the pipeline by the excavator without involving other road construction equipment (for example, a pipelaying crane). The proposed design of the working body allows speeding pipeline repair by reducing the time spent on changing or relocating the equipment, which as a result reduces the cost of repair work. Conclusions. Calculations of the excavator hydraulic system have been carried out. In addition, as a result of theoretical studies, calculated dependences have been obtained, which made it possible to establish the stability coefficient of the excavator of the third size group when working with upgraded equipment and the pipeline diameter in the range of 720 ...1420 mm. As a result of the research, it was found that the proposed equipment is effective for carrying out random repairs of pipelines with diameters of 720, 1020 and 1220 mm. The stability of the machine in the most dangerous positions is being carried out. The calculation shows that when the excavator does demolition works of a pipeline with a diameter of 1420 mm, there is a danger of overturning the machine due to a decrease in the Ku coefficient below the permissible value.

Bang-Bang Control of the Multi-Cylinder Synchronization Hydraulic System of Pusher

2013 ◽  
Vol 850-851 ◽  
pp. 632-635
Author(s):  
Guo Hua Zhao
Keyword(s):  
Hydraulic System ◽  
Control Method ◽  
Engineering Application ◽  
Performance Standard ◽  
Variable Load ◽  
Continuous Control ◽  
Synchronous Motion ◽  
The Stability ◽  
The Cost ◽  
Bang Bang Control

To the pusher and variable load synchronous motion of hydraulic dual-cylinder system, the "Bang-Bang" control mechanism and the non-continuous control technology are adopted. The hydraulic system that used the ordinary realizes a synchronization error less than two percent. The stability and reliability of the system are improved and the cost of the system is reduced. Especially in the pusher and other industrial areas, the hydraulic system is more suitable for engineering application. By the ability of computers software servo control, the output of the application system can meet the performance standard and make complex mechanical control. it proves that a non-continuous control method is an effective way to carry out the digital control.

scholarly journals Scientific and organizational support for implementation of the strategy of innovative development of production in road construction complex with application of automobraders with additional universal working equipment

2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Nikolai Tokar ◽  
Zelgedin Mevlidinov ◽  
Tatiana Levkovich ◽  
Alexandr Foevtsov
Keyword(s):  
Organizational Support ◽  
Main Idea ◽  
Road Construction ◽  
Technical Condition ◽  
Third Party ◽  
Capital Investments ◽  
Hydraulic Motor ◽  
Road Building ◽  
Loading And Unloading ◽  
The Cost

The work outlines ways to intensify the production of planning and loading and unloading operations in a road-building complex using motor graders with controlled excavator equipment using comparative, logical analysis and synthesis. The study of the representativeness and technical condition of car parks, as well as indicators of their application revealed the following: the structure of machine parks contains a narrow range of nomenclature and the machines of small and medium sizes prevail; in the structure of the machine parks, the outdated planning and earthmoving machinery are represented – 52,7 %; loaders from 5,1 % to 10,5 %; hand mechanized tools – 17 %; equipment with high physical deterioration is more than 60 %; equipment leased from third-party organizations on a permanent basis is 17 %, and the total amount leased is 1,5 %. The main idea of the new approach is the idea of forming a compact fleet of vehicles in order to reduce the cost of maintaining it by incorporating universal equipment into the composition, each unit of which can perform the functions of 2–4 machines with the complete elimination of works on re-equipment of replaceable working bodies. In the course of research, additional working equipment of a motor grader was proposed, located in front of the machine, is a loader’s working equipment consisting of a bucket, boom, thrust, hydraulic bucket and boom control cylinder, in the upper part of the rear wall of the bucket, rigidly mounted excavator equipment, represented by two brackets driven by a hydraulic motor. Inside the brackets by means of a swivel is fixed an arrow with a handle, in the coupling of which there is a hydraulic motor, which is connected to the bucket. Lifting and lowering excavator equipment is performed by two hydraulic cylinders, hinged to the brackets and the boom. Forecast calculations showed that the cost of a modular multifunctional motor grader will on average be about 4 million rubles. The volume of capital investments for the purchase of a compact fleet of vehicles for an average enterprise of a road-building complex in the urban economy based on the use of multi-functional modular equipment will amount to approximately 24 million rubles. The payback period is 2–2,5 years. As a result of the research, the composition and structure were determined, the main ways of intensifying the planning and loading and unloading operations in the road-building complex with the use of motor graders with controlled excavator equipment were proposed.

scholarly journals Determination of economically viable option of liquidation the consequences of external dump deformation

2021 ◽  
Vol 280 ◽  
pp. 08014
Author(s):  
Yevheniy Babets ◽  
Oleh Anisimov ◽  
Oleksandr Shustov ◽  
Vitalina Komirna ◽  
Iryna Melnikova
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Safety Factors ◽  
Viable Option ◽  
The Third ◽  
The Stability ◽  
The Cost ◽  
Technical And Economic Indicators ◽  
Processing Enterprise

The safety factors for different variants of operation development were obtained, on the basis of which the technical and economic indicators were established and the most expedient way of restoration of dump operations in conditions of the formed landslide was chosen. The solutions were proposed for the external dump No 2 of the Central Ore Mining and Processing Enterprise (COMPE), that allow to continue its future operation. When working in the conditions of the formed landslide, three variants of the further dump operation are modeled: the first one - with landslide removal and unloading of the upper dump horizons, the second one - without landslide removal and involvement of disturbed lands in land allotment, the third one - with the landslide loading. Based on the built sections of the dump and defined physical and mechanical properties, the stability factors were obtained for different options of the operation development, which made it possible to determine the appropriate option to eliminate the effects of the dump slide deformations. As a result of the calculations, the cost flows for each of the proposed options of the formation of the end contour of the dump No 2 are determined.

scholarly journals Contribution of geological mapping in road construction: an example from Verta - Kozani National road, Kastania area

2007 ◽  
Vol 40 (4) ◽  
pp. 1652
Author(s):  
G. A. Georgiadis ◽  
M. D. Tranos ◽  
Th. K. Makedon ◽  
G. Ch. Dimopoulos
Keyword(s):  
Cost Reduction ◽  
Road Construction ◽  
Geological Mapping ◽  
Geological Investigation ◽  
Area Of Interest ◽  
Geological Maps ◽  
Engineering Geological Maps ◽  
The Stability ◽  
The Cost ◽  
National Road

Road construction is a complex and multipart work that is decisively depended on the geological investigation of the area of interest. The geological investigation, which ought to be carried out from the early stages of the study and construction, contributes significantly in the cost reduction and corresponding increase of the construction safety. The proposed methodology that should be implemented during the geological investigation for this kind of constructions includes geological mapping and construction of geological and engineering geological maps. These maps display, in each case, the necessary data and are supplemented by geological crosssections as well as stereographic projections (e.g. Schmidt diagrams), which evaluate the tectonic conditions of the area and the stability conditions of artificial road slopes. An example of geological investigation based on the above methodology is presented, regarding the Kastania section of the Veria - Kozani (old) national road.

scholarly journals Black Hole Algorithm for Sustainable Design of Counterfort Retaining Walls

2020 ◽  
Vol 12 (7) ◽  
pp. 2767 ◽  
Author(s):  
Víctor Yepes ◽  
José V. Martí ◽  
José García
Keyword(s):  
Black Hole ◽  
Sustainable Design ◽  
Retaining Walls ◽  
The Other ◽  
Trade Off ◽  
Construction Company ◽  
Geometric Variables ◽  
The Stability ◽  
The Cost ◽  
Black Hole Algorithm

The optimization of the cost and CO 2 emissions in earth-retaining walls is of relevance, since these structures are often used in civil engineering. The optimization of costs is essential for the competitiveness of the construction company, and the optimization of emissions is relevant in the environmental impact of construction. To address the optimization, black hole metaheuristics were used, along with a discretization mechanism based on min–max normalization. The stability of the algorithm was evaluated with respect to the solutions obtained; the steel and concrete values obtained in both optimizations were analyzed. Additionally, the geometric variables of the structure were compared. Finally, the results obtained were compared with another algorithm that solved the problem. The results show that there is a trade-off between the use of steel and concrete. The solutions that minimize CO 2 emissions prefer the use of concrete instead of those that optimize the cost. On the other hand, when comparing the geometric variables, it is seen that most remain similar in both optimizations except for the distance between buttresses. When comparing with another algorithm, the results show a good performance in optimization using the black hole algorithm.

scholarly journals Longevity of Raw and Lyophilized Crude Urease Extracts

2021 ◽  
Vol 2 (2) ◽  
pp. 325-334
Author(s):  
Neda Javadi ◽  
Hamed Khodadadi Tirkolaei ◽  
Nasser Hamdan ◽  
Edward Kavazanjian
Keyword(s):  
Crude Extract ◽  
Room Temperature ◽  
Low Cost ◽  
Extraction Process ◽  
Crude Extracts ◽  
Simple Extraction ◽  
Commercial Applications ◽  
Stable Source ◽  
The Stability ◽  
The Cost

The stability (longevity of activity) of three crude urease extracts was evaluated in a laboratory study as part of an effort to reduce the cost of urease for applications that do not require high purity enzyme. A low-cost, stable source of urease will greatly facilitate engineering applications of urease such as biocementation of soil. Inexpensive crude extracts of urease have been shown to be effective at hydrolyzing urea for carbonate precipitation. However, some studies have suggested that the activity of a crude extract may decrease with time, limiting the potential for its mass production for commercial applications. The stability of crude urease extracts shown to be effective for biocementation was studied. The crude extracts were obtained from jack beans via a simple extraction process, stored at room temperature and at 4 ℃, and periodically tested to evaluate their stability. To facilitate storage and transportation of the extracted enzyme, the longevity of the enzyme following freeze drying (lyophilization) to reduce the crude extract to a powder and subsequent re-hydration into an aqueous solution was evaluated. In an attempt to improve the shelf life of the lyophilized extract, dextran and sucrose were added during lyophilization. The stability of purified commercial urease following rehydration was also investigated. Results of the laboratory tests showed that the lyophilized crude extract maintained its activity during storage more effectively than either the crude extract solution or the rehydrated commercial urease. While incorporating 2% dextran (w/v) prior to lyophilization of the crude extract increased the overall enzymatic activity, it did not enhance the stability of the urease during storage.

scholarly journals Competing Conventions with Costly Information Acquisition

Games ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 53
Author(s):  
Roberto Rozzi
Keyword(s):  
Information Acquisition ◽  
Evolutionary Model ◽  
Equilibrium Selection ◽  
The Other ◽  
Group Interactions ◽  
Social Coordination ◽  
Long Run ◽  
Stochastic Stability Analysis ◽  
The Stability ◽  
The Cost

We consider an evolutionary model of social coordination in a 2 × 2 game where two groups of players prefer to coordinate on different actions. Players can pay a cost to learn their opponent’s group: if they pay it, they can condition their actions concerning the groups. We assess the stability of outcomes in the long run using stochastic stability analysis. We find that three elements matter for the equilibrium selection: the group size, the strength of preferences, and the information’s cost. If the cost is too high, players never learn the group of their opponents in the long run. If one group is stronger in preferences for its favorite action than the other, or its size is sufficiently large compared to the other group, every player plays that group’s favorite action. If both groups are strong enough in preferences, or if none of the groups’ sizes is large enough, players play their favorite actions and miscoordinate in inter-group interactions. Lower levels of the cost favor coordination. Indeed, when the cost is low, in inside-group interactions, players always coordinate on their favorite action, while in inter-group interactions, they coordinate on the favorite action of the group that is stronger in preferences or large enough.

scholarly journals Computing the Exact Number of Similarity Classes in the Longest Edge Bisection of Tetrahedra

Mathematics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1447
Author(s):  
Jose P. Suárez ◽  
Agustín Trujillo ◽  
Tania Moreno
Keyword(s):  
Data Structure ◽  
Stability Condition ◽  
Open Problem ◽  
Integer Arithmetic ◽  
Exact Number ◽  
Similarity Class ◽  
The Stability ◽  
High Level ◽  
The Cost

Showing whether the longest-edge (LE) bisection of tetrahedra meshes degenerates the stability condition or not is still an open problem. Some reasons, in part, are due to the cost for achieving the computation of similarity classes of millions of tetrahedra. We prove the existence of tetrahedra where the LE bisection introduces, at most, 37 similarity classes. This family of new tetrahedra was roughly pointed out by Adler in 1983. However, as far as we know, there has been no evidence confirming its existence. We also introduce a new data structure and algorithm for computing the number of similarity tetrahedral classes based on integer arithmetic, storing only the square of edges. The algorithm lets us perform compact and efficient high-level similarity class computations with a cost that is only dependent on the number of similarity classes.

The Mitigation of the French Nuclear Option: New Industrial Realism and Technical Democracy

2002 ◽  
Vol 13 (2) ◽  
pp. 263-279 ◽  
Author(s):  
Dominique Finon
Keyword(s):  
Waste Management ◽  
Electricity Markets ◽  
Social Preferences ◽  
Public Inquiry ◽  
The Future ◽  
Parliamentary Committee ◽  
Set Up ◽  
The Stability ◽  
The Cost ◽  
Phase Out

Nuclear phase-out policies and the European obligation to liberalise electricity markets could put the French nuclear option dramatically at risk by influencing social preferences or by constraining power producers' investment choices in the future. So far, the particular institutional set-up which has allowed the efficient build-up and operation of several series of standardised reactors preserves the stability of the main elements of the option. However, important adaptations to the evolving industrial and political environment occur and contribute to changing the option. Some institutional changes (such as local public inquiry, creation of a Parliamentary committee, independence of safety authorities) and divergence between industrial interests already allow debates on internal options such as reprocessing, type of waste management deposits, ordering of an advanced PWR. These changes improve the cost transparency, even if internalisation of nuclear externalities (cost of insurance, provisions for waste management) is still incomplete. However, when effective, this internalisation would not affect definitively the competitive position of the nuclear production because of the parallel internalisation of CO2 externalities from fossil fuel power generation in the official rationale. Consequently the real issue for the future of the nuclear option in France remains the preservation of social acceptability in the perception of nuclear risks.

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