{"title":"Study of traction dynamics of a caterpillar tractor wagon","authors":"S. Voynash, A. Voynash","doi":"10.17816/0321-4443-66376","DOIUrl":"https://doi.org/10.17816/0321-4443-66376","url":null,"abstract":"Existing caterpillar dump trucks, including foreign ones, with relatively small amounts of work carried out seasonally, for example, when building roads in logging areas, are not effective enough. It is proposed to use trail equipment available for logging needs for road construction. LLC «Plant of Caterpillar Machines» developed a schematic solution for a caterpillar tractor wagon obtained by equipping the serial rubber trail tractor TGL-4.04 with a large-capacity dump truck and using bulldozer equipment with a turning blade. In order to assist the customer using the caterpillar dump truck based on the trail tractor TGL-4.04 in determining the loading parameters corresponding to the modes of the most efficient use of the machine under specific operating conditions, the tasks of developing fairly simple nomograms graphically linking the main load parameters of a caterpillar tractor wagon characteristics with typical operating conditions. The technique of calculation of dynamic characteristics of a caterpillar tractor wagon is stated. Variants of a dynamic passport are proposed, including a nomogram of the regular-route load. Each version of the dynamic passport contains two quadrants: in the right quadrant, the dynamic characteristic «on the engine»; in the left quadrant, the dependences of the dynamic factor on the elevation angle of the terrain and the drag coefficients for medium and heavy conditions are presented (dynamic characteristic «according to traffic conditions»). Examples of the analysis of the nature of the movement of a caterpillar tractor wagon at a given speed under given conditions are given. The proposed improved version of the dynamic passport with the nomogram of the regular-route load makes it possible to formulate practical recommendations on the values of the regular-route loads and the speeds of the caterpillar tractor wagon when transporting goods under specific operating conditions.","PeriodicalId":136662,"journal":{"name":"Traktory i sel hozmashiny","volume":"224 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127183932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Formation the driving force of wheeled and caterpillar machine-tractor units","authors":"M. Makhmutov, Yu. R Khismatullina","doi":"10.17816/0321-4443-66391","DOIUrl":"https://doi.org/10.17816/0321-4443-66391","url":null,"abstract":"On the basis of existing dependencies describing the traction-coupling properties of wheeled and caterpillar machine-tractor units, theoretical and experimental investigations, a model of the formation of the driving traction force of units depending on the weight of the tractor, coupling properties of the propulsion unit, load distribution and propulsion slipping is obtained. The analysis of calculated coefficients shows a considerable variation of values, which causes difficulties in using in the calculations. Therefore it’s necessary to know their values at each interaction of the tractor propulsion unit with the soil. The same values of slipping can be obtained with different values of the coefficients. The task is simplified if data of this dependence have the same coefficient. During field investigations an active experiment was developed i.e. the levels of factors variation changed purposefully depending on the conditions of conducting each experiment. Composite B-plans (Box-design) of the second order were realized. The following parameters were chosen as the variable factors: the coefficient of the using coupling weight, the coefficient of traction and the weight of the tractor. The works were conducted according to the plan of the three-factor experiment matrix. As the agricultural field were a freshly plowed field, a stubble field and a wet meadow, with the coefficients of traction of 0,50, 0,65 and 0,80 respectively. The value of resistance to movement was fixed by a dynamometer during towing tractors MTZ-82, MTZ-2022 and MTZ-3022 DC.1 in neutral on the various agricultural fields. Efforts on the hook were changed by shifting gears in the gearbox of a towed tractor whose engine operated in the compressor mode. The coefficient of traction was determined with completely braked wheels of the tractor and towing it with a towing vehicle during simultaneously measuring the force on the coupling with the help of a dynamometer. The obtained model of driving force formation for wheeled and tracked machine-tractor units takes into account the weight of the tractor, coupling properties of propulsion units, load distribution, slipping and has a minimum number of experimental coefficients, which makes it more accessible and easily used for engineering calculations.","PeriodicalId":136662,"journal":{"name":"Traktory i sel hozmashiny","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124721392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The power unit of universal tractors of traction class 1,4 with an integrated starter generator","authors":"A. Bekeev, A. Y. Aliev, S. Aliev","doi":"10.17816/0321-4443-66357","DOIUrl":"https://doi.org/10.17816/0321-4443-66357","url":null,"abstract":"The technical development of tractor designs is characterized by an increase in the power of consumers, the use of electric drive units. The load on the electric system of a modern tractor is constantly growing and exposes the existing 12-volt systems to excessive loading. To date, with the relatively low efficiency of traditional generators it is impossible to meet the growing needs of tractors and its systems. The solution of the problem of increasing the power simultaneously with increasing the efficiency (up to 85...90 %) could become an integrated starter-generator. Possessing sufficient power in the propulsion mode (up to 8 kW), the starter generator makes it possible to improve the starting and energy characteristics of the internal combustion engines of the tractor. The proposed design of electrical machines is located between the engine cylinder assembly and the tractor clutch. The adopted configuration allows to transfer considerable power in both directions, improves the starting qualities of diesel engines of tractors, and also realize the functions of damping the torsional oscillations of the crankshaft, which significantly reduces the noise and vibration of the engine. Based on the results of the study, the choice of a starter-generator device based on a valve motor is justified in connection with diesel engines of universal tractors of traction class 1,4 and a scheme for its placement in the clutch housing without changing its basic design has been developed. The advantage of the proposed design is the use of electric machines to start the engine, which in this case is switched to the electric motor mode and switches to the generator mode during operation, providing power to the on-board network. In addition, combining the starter and generator in a single unit simplifies the design, reduces the cost of manufacturing and assembly, which is an advantage in terms of production costs, replacing the starter and generator and on some tractors the starting piston engine.","PeriodicalId":136662,"journal":{"name":"Traktory i sel hozmashiny","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131058297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Alatyrev, A. P. Yurkin, I. Kruchinkina, A. Alatyrev
{"title":"Production testing of the new method of mechanical harvesting of cabbage","authors":"S. Alatyrev, A. P. Yurkin, I. Kruchinkina, A. Alatyrev","doi":"10.17816/0321-4443-66354","DOIUrl":"https://doi.org/10.17816/0321-4443-66354","url":null,"abstract":"White cabbage is a traditional vegetable crop in Russia, easily damaged by mechanical influences. In addition, cleaning is accompanied by significant labor and material costs. Taking into account the above-mentioned features, a new method for mechanized harvesting of cabbage was proposed, where cabbage heads are firstly aligned in the row by lifters, then they are forwarded under the clamping belt, where afterwards they are fixed and cut. Cut-off heads are forwarded by outside-mounted and clamping transporters on to a sorting transporter-cutter. On the sorting transporter-cutter, the heads are inspected. Workers pick out cabbage with long cabbage stumps and rosette leaves and insert them into the holes of the plate-shaped army duck transporter-cutter, where they are re-cut when passing through the passive knife. As a result, the rosette leaves are separated from the heads, and the cut-out cabbage stumps slide down the tray to the ground. Further, the heads and loose leaves, separated from the heads after repeated cutting enter the rod elevator, where leaves are again cut off, and the heads are sent for shipment. Unlike the traditional method of harvesting cabbage, head of cabbage are shipped by a cabbage harvesting machine first to a flexible trough floor, mounted on a special rack on the vehicle platform above the removable containers. Then, the heads from the flooring are gently transferred to containers for subsequent storage in them. After filling the containers, the vehicle is sent to a storage facility where, with a forklift truck, the loaded containers are replaced by empty ones, leaving the flexible deck with the platform rack for the next cycle of work. In the harvest season of 2017, the proposed technology for mechanized harvesting of cabbage was tested in the production conditions of LLC «Chapaevskoye» in the Mari El Republic. The conducted production tests confirmed the conformity of the products to the agrotechnical requirements and the possibility of organizing the harvesting process continuously in a sparing mode.","PeriodicalId":136662,"journal":{"name":"Traktory i sel hozmashiny","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132732155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Results of modeling the secondary kinematics of the piston in the cylinder of a high-speed diesel engine","authors":"C. B. Putintsev, A. G. Kirillov, A. S. Ratnikov","doi":"10.17816/0321-4443-66396","DOIUrl":"https://doi.org/10.17816/0321-4443-66396","url":null,"abstract":"The relevance of the investigation of the processes of secondary kinematics of the piston in the internal combustion engine’s cylinder is due to their strong influence on such indicators as mechanical losses, wear, noise, vibration, oil consumption, and their insufficient knowledge concerning high-speed piston engines. The purpose of the research was an assessment of the influence on the character of the secondary kinematics of the piston of the high-speed internal combustion engine design factors, operating conditions and lubricant and on this basis finding the ways to improve the lubrication and friction conditions in coupling of the «cylinder-piston skirt». The tasks to be performed to achieve the research goal were in an identification the most significant parameters of the construction on the piston's secondary kinematics, mode of operation and properties of the lubricant; obtaining diagrams of the piston's secondary kinematics depending on the change in the values of the influencing factors, as well as the analysis of the obtained results and the development of recommendations aimed at reducing friction and wear in the piston-cylinder-unit. For the subject of the research the piston of the high-speed diesel engine 1CH 8,5/8,0, having a barrel-shaped profile of the piston skirt in the serial production and a negative dezaksial of piston pin, was chosen. The research method is mathematical modeling using the calculation program PISTON-DHT. Discussion of the obtained results made it possible to reveal the two most influential parameters on the character of the secondary kinematics of the piston: the dezaksial of piston pin and piston skirt profile. The variation of the sign and the values of these indicators were established an expedience to switch from a negative one to the positive dezaxial and an application of rational profile of the piston skirt. For the two most dynamically loaded strokes of the working cycle «Compression» and «Expansion», the dominance of the piston movement in the position of the scraper relative to the adjacent side of the cylinder wall was highlighted. The generalized recommendations aimed at eliminating the dominance of this undesirable situation can be taken into account and used in the design and completion of high-speed internal combustion engines pistons in order to minimize mechanical losses and wear.","PeriodicalId":136662,"journal":{"name":"Traktory i sel hozmashiny","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114965785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Experimental determination of the main load factor of threaded connection of connecting rod head with oblique connector","authors":"A. Gots","doi":"10.17816/0321-4443-66384","DOIUrl":"https://doi.org/10.17816/0321-4443-66384","url":null,"abstract":"According to the methodology developed earlier the experimental-calculated investigations of a determination of the stresses in the rod bolts of connecting rods with an oblique connector when the bolt was tightened, and after loading the connecting rod with an external load were conducted. The main point of an investigation’s methodology of the stress-strain state of connecting rod bolts is in that on the outer circumference of the bolt body at some distance from each other strain gauges are glued. The coordinates of the measurement points must be precisely defined in a rectangular coordinate system, and one of the coordinates along the z-axis is taken by the stresses in the cross section of the bolt body. The simplest formulas for calculations have been obtained if the strain gauges are glued along the circumference 120 ° from each other. According to the average value for all three indications of strain gauges determines the tensile stress. As shown by the result of experimental investigations during the tightening process the body of connecting rod experiences tensile and bending stresses. It’s known that when installation shells in the crank head of the connecting rod, their length exceeds the length of the saddle by the protrusion amount. Because of the protrusion of the shell the entire load during tightening the bolts falls on the shell and it is applied eccentrically. However even after a deformation of the shell around the perimeter, the force on bolt is transmitted through the average radius of the thread. When the external force of the connecting rod is applied to the rod bolt only a part of the load is transferred, it’s equal to the product of this force by the coefficient of the main load. After experimental determination the stress in the connecting rod bolts, as well as the force in each of the bolts with the oblique connector, the main load of the connecting rod is determined by the experiment-calculated investigation.","PeriodicalId":136662,"journal":{"name":"Traktory i sel hozmashiny","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121643575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Likhanov, A. V. Grebnev, M. Skryabin, A. Toropov
{"title":"Adjustment characteristics of the diesel engine operating on natural gas","authors":"V. Likhanov, A. V. Grebnev, M. Skryabin, A. Toropov","doi":"10.17816/0321-4443-66316","DOIUrl":"https://doi.org/10.17816/0321-4443-66316","url":null,"abstract":"The article presents adjustment characteristics of the diesel engine in terms of the fuel injection advance angle during gas-diesel process operation. Currently the problem of reducing production costs is relevant for many producers. In the agricultural industry a considerable cost item consist of fuel costs for mobile energy vehicle. One way to reduce these costs is using of alternative cheaper fuel types. The natural gas is one of such fuels. The most common type of engine in agriculture is a diesel. In spite of the large number of conducted works to convert diesel engines to natural gas, the question of conversion high-powered low-dimension diesel engines has not been sufficiently investigated. As an object of research D-245.7 (4CHN11/12,5) was chosen. The conversion of diesel engine to gas-diesel process is the purpose of an investigation. One of the stages of the research was conducting bench tests with taking adjustment characteristics of the fuel injection advance angle. As a result of bench tests the parameters of combustion process, characteristics of heat emission, effective indicators of the diesel engine at various values of the fuel injection advance angle during work on diesel and gas-diesel processes are determined. The main following conclusions are: 1) during the diesel engine’s operation on the gas-diesel process an increase of temperature, pressure, the rate of pressure rise in cylinder are observed; 2) the power parameters of diesel engine during the work on gas-diesel process are completely preserved; 3) under such conversion the diesel engine to natural gas one of recommendations is a reduction of the fuel injection advance angle.","PeriodicalId":136662,"journal":{"name":"Traktory i sel hozmashiny","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128768621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Sirotin, M. Zhileykin, A. G. Sapegin, S. Zlenko
{"title":"Prerequisites for the creation of an integrated system for leveling and cushioning framework of combine harvesters","authors":"P. Sirotin, M. Zhileykin, A. G. Sapegin, S. Zlenko","doi":"10.17816/0321-4443-66335","DOIUrl":"https://doi.org/10.17816/0321-4443-66335","url":null,"abstract":"This review-analytical article is devoted to the definition and justification of promising areas of modern combine-building. The paper presents an analysis of studies conducted in Russia and abroad, on the effect of the bias of soil preparation on one of the most important indicators of the efficiency of the operation of combine harvesters-total grain losses. To ensure a given efficiency of work on the slopes, the need to use special combines or to make changes to the existing ones is shown. The classification of combine harvesters is given depending on the suitability for work in fields with a slope. For each of the selected groups, a detailed analysis of their structures is carried out, distinctive features are identified, and mechanisms and systems are determined that ensure a reduction in grain losses of the combine harvester on soil preparation with complex terrain. The main reasons for the widespread use of such systems are identified. Based on the experimental data obtained during field testing of combine harvesters, the level of dynamic loads acting on their frameworks is shown. Spectral analysis of the acting accelerations on the adapter, arms of front and rear double-reduction axles are carried out. Based on the analysis the main frequencies at which the loads are formed are identified. The need for the introduction of suspension systems, which could also perform the function of leveling framework and facilitate the process of copying the topography of the soil preparation with a header is explained. A dynamic model of a combine harvester with a system of leveling and cushioning is presented, arguments are given for the creation and implementation of such systems. Conclusions are drawn and directions for further research on the development of multifunctional systems for individual implementations of combine harvesters working on soil preparation with complex terrain and having a competitive level of operational properties are determined.","PeriodicalId":136662,"journal":{"name":"Traktory i sel hozmashiny","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133438342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Exper-imental study of the characteristics of tractor pneumatic tires","authors":"S. Parkhomenko, G. Parkhomenko","doi":"10.17816/0321-4443-66350","DOIUrl":"https://doi.org/10.17816/0321-4443-66350","url":null,"abstract":"One of the factors affecting the performance indicators of machine-tractor units is the perfection of the movers, among which the wheeled ones are dominant. Optimization of the parameters of the pneumatic tire as one of the elements of the oscillatory system and the main element of wheeled mover is one of the directions of increasing the efficiency of operation of machine-tractor units. The investigations were carried out with the aim of developing an effective technique for the experimental determination of the elastically damping, deformation, traction characteristics of tractor pneumatic tires, which makes it possible to correctly compare their various variants. In the course of experimental studies, the characteristics of pneumatic tires of size 16.9-30 radial (serial) model F-39 and diagonally parallel (experimental) structures were studied. Facility for testing pneumatic tires (tire tester) allows to perform the determination of the required indicators in real operating conditions. The developed technique of experimental researches allows to define necessary characteristics of pneumatic tires, to carry out comparisons of various variants. The deformation characteristics of pneumatic tires in the general case of their loading show that they experience longitudinal, torsional and radial deformations. The presence in 16.9R30 serial tire in contrast to the 16.9-30DP experimental tire of radial deformation directed from the wheel axis in the zone in front of the contact surface under the driving rolling mode causes large hysteresis losses in it. The experimental traction characteristics of pneumatic tires show a higher efficiency of the diagonal-parallel 16.9-30DP tire and its less slipping, which predetermines less abrasion of the soil with this type of tire. It has been established that the application of the experimental tires","PeriodicalId":136662,"journal":{"name":"Traktory i sel hozmashiny","volume":"07 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127211136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mathematical modeling of dynamics of movement of the compound piston in the cylinder of the internal combustion engine","authors":"S. Smirnov, A. Makarov, R. Abu-Nidzhim","doi":"10.17816/0321-4443-66361","DOIUrl":"https://doi.org/10.17816/0321-4443-66361","url":null,"abstract":"Cylinder piston group is the main part of friction in the engine, where usually mechanical losses appear, that is why its work and design should be considered from the point of view of tribology. The task of designing a cylinder - piston group as a friction unit is to select the basic geometric dimensions, the profile of the guide part in the longitudinal and transverse planes, the diametric gap, the coordinates of the piston pin arrangement and the center of mass. The solution of these problems is directly dependent on the possibility of studying the complex plane-parallel motion of the piston within the piston-cylinder liner clearance in the lubricant layer. At present, compound pistons are gaining traction from forced diesel engines with increased loads on the cylinder-piston group. The study of the movement of the compound pis-ton must include the solution of interrelated tasks: the investigation of the motion of the piston crown with a set of piston rings and the study of the motion of the piston skirt, taking into account the effect of the rocking motion of the connecting rod on it. The derivation of the equations of motion of all components of the piston and connecting rod is given in the article. Their combined solution and the resulting equations allow us to investigate the transverse motion of the crown of the composite piston and to evaluate the operation of the piston rings, and also taking into account the hydrodynamic lubrication of the skirt, to carry out a comprehensive study of the state of the skirt of the compound piston and, first and foremost, to investigate the influence of its basic design parameters on the conditions of the hydrodynamic grease. The developed mathematical model will allow on the basis of complex research the influence of the above parameters to develop a composite piston design that provides high technical and economic parameters of the engine.","PeriodicalId":136662,"journal":{"name":"Traktory i sel hozmashiny","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126209979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}