Oligomers/polymers formed during the thermal-oxidative ageing of ester-based aviation turbine oils have been investigated, using pentaerythritol tetraheptanoate as a model ester. The principal polymer structures in the primary ageing state were revealed by means of chromatographic and spectroscopic methods. The most probable structures are dicarboxylic acid polyesters with variable amounts of α,ω-dicarboxylic acids having chain lengths of C2 up to C7 The C7-branches also contained ester-bonded hydroxy as well as oxo substituents. Pentaerythritol triheptanoate discarboxylic acid mono esters were active precursors in polymer formation.
{"title":"Polymer formation during thermal-oxidative ageing of aviation turbine oils","authors":"H. Fuchs, A. Zeman","doi":"10.1002/JSL.3000100102","DOIUrl":"https://doi.org/10.1002/JSL.3000100102","url":null,"abstract":"Oligomers/polymers formed during the thermal-oxidative ageing of ester-based aviation turbine oils have been investigated, using pentaerythritol tetraheptanoate as a model ester. The principal polymer structures in the primary ageing state were revealed by means of chromatographic and spectroscopic methods. The most probable structures are dicarboxylic acid polyesters with variable amounts of α,ω-dicarboxylic acids having chain lengths of C2 up to C7 The C7-branches also contained ester-bonded hydroxy as well as oxo substituents. Pentaerythritol triheptanoate discarboxylic acid mono esters were active precursors in polymer formation.","PeriodicalId":17149,"journal":{"name":"Journal of Synthetic Lubrication","volume":"99 1","pages":"1-22"},"PeriodicalIF":0.0,"publicationDate":"1993-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81320780","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}
Biodegradation test methods have been compared with regard to test conditions and test parameters. It has been shown that three methods are, in principle, suitable for non-water soluble products. These are the Sturm test (OECD no. 301B), the MITI test (OECD 301 C), and the CEC L-33-T-82 test method. A comparison in an actual test showed that the CEC test gives the highest biodegradation values, while the Sturm test and the MITI test give lower values. It is noted that the CEC test measures the amount of material used for both energy production and growth of the biomass, while the other methods measure only the material used for energy production. A possible explanation for the difference between the Sturm and the MITI test results is given. The CEC test is shown to be more suitable for the lubricant industry. Applications of biodegradable lubricants are reviewed, particularly hydraulic fluids. It is shown that rape seed oil (natural ester) and synthetic polyol esters have similarities regarding structure but also significant differences. This results in much better thermal and oxidative stability for the synthetic esters. These also offer the possibility of making a range of products of different ISO grades with similar properties. Brief consideration is given to future potential, notably for biodegradable four-stroke lubricants. Finally, there is a timely reminder that, owing to the present limited availability of natural oils and fats and their cost, only 19% of the market for mineral oil base fluids could be replaced by natural oils and fats and their derivatives.
{"title":"Testing, application, and future development of environmentally friendly ester base fluids","authors":"G. V. D. Waal, Dirk Kenbeek","doi":"10.1002/JSL.3000100105","DOIUrl":"https://doi.org/10.1002/JSL.3000100105","url":null,"abstract":"Biodegradation test methods have been compared with regard to test conditions and test parameters. It has been shown that three methods are, in principle, suitable for non-water soluble products. These are the Sturm test (OECD no. 301B), the MITI test (OECD 301 C), and the CEC L-33-T-82 test method. A comparison in an actual test showed that the CEC test gives the highest biodegradation values, while the Sturm test and the MITI test give lower values. It is noted that the CEC test measures the amount of material used for both energy production and growth of the biomass, while the other methods measure only the material used for energy production. A possible explanation for the difference between the Sturm and the MITI test results is given. The CEC test is shown to be more suitable for the lubricant industry. Applications of biodegradable lubricants are reviewed, particularly hydraulic fluids. It is shown that rape seed oil (natural ester) and synthetic polyol esters have similarities regarding structure but also significant differences. This results in much better thermal and oxidative stability for the synthetic esters. These also offer the possibility of making a range of products of different ISO grades with similar properties. \u0000 \u0000 \u0000 \u0000Brief consideration is given to future potential, notably for biodegradable four-stroke lubricants. Finally, there is a timely reminder that, owing to the present limited availability of natural oils and fats and their cost, only 19% of the market for mineral oil base fluids could be replaced by natural oils and fats and their derivatives.","PeriodicalId":17149,"journal":{"name":"Journal of Synthetic Lubrication","volume":"16 1","pages":"67-83"},"PeriodicalIF":0.0,"publicationDate":"1993-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73351998","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}
The evaluation of oil soluble polyethers (OSPs) in fully and semi-synthetic automotive crankcase lubricants is described. Parameters including viscosity, additive compatibility, lubricity/wear performance, oxidative stability, and piston cleanliness are assessed. It is possible to formulate OSP-containing lubricants with lower VI improver treatment level, superior viscometric properties, and Noack volatilities to comparable lubricants without OSPs. Data from engine tests and field trials show that semi- and fully synthetic lubricants containing OSP possess all the performance advantages of ester-containing lubricants, with additional benefits in terms of engine and inlet system cleanliness. The results indicate that OSPs have excellent potential as synthetic lubricant base fluids.
{"title":"Oil soluble polyethers in automotive crankcase lubricants","authors":"R. Cracknell","doi":"10.1002/JSL.3000100104","DOIUrl":"https://doi.org/10.1002/JSL.3000100104","url":null,"abstract":"The evaluation of oil soluble polyethers (OSPs) in fully and semi-synthetic automotive crankcase lubricants is described. Parameters including viscosity, additive compatibility, lubricity/wear performance, oxidative stability, and piston cleanliness are assessed. It is possible to formulate OSP-containing lubricants with lower VI improver treatment level, superior viscometric properties, and Noack volatilities to comparable lubricants without OSPs. Data from engine tests and field trials show that semi- and fully synthetic lubricants containing OSP possess all the performance advantages of ester-containing lubricants, with additional benefits in terms of engine and inlet system cleanliness. The results indicate that OSPs have excellent potential as synthetic lubricant base fluids.","PeriodicalId":17149,"journal":{"name":"Journal of Synthetic Lubrication","volume":"94 1","pages":"47-66"},"PeriodicalIF":0.0,"publicationDate":"1993-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81083472","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}
M. Aderi, G. J. Johnsto, H. Spikes, T. Balson, M. G. Emery
It is now recognised that, for many practical applications, an important property of a lubricant is its ability to generate thick, elastohydrodynamic (EHD) films in concentrated contacts. This paper describes a study of the EHD film- forming properties of polyalkylenie glycol lubricants. A wide range of polyglycol structures have been examined, with different monomer types, initiators, and molecular weights. Film thickness has been measured at several different temperatures using both conventional and ultra-thin film interferometry. From the measured film thicknesses, the effective pressure–viscosity coefficients of the lubricants have been evaluated. This has enabled a systematic investigation of the effect of polyalkylene glycol structure on both pressure–viscosity coefficient and EHD film formation.
{"title":"The film‐forming properties of polyalkylene glycols","authors":"M. Aderi, G. J. Johnsto, H. Spikes, T. Balson, M. G. Emery","doi":"10.1002/JSL.3000100103","DOIUrl":"https://doi.org/10.1002/JSL.3000100103","url":null,"abstract":"It is now recognised that, for many practical applications, an important property of a lubricant is its ability to generate thick, elastohydrodynamic (EHD) films in concentrated contacts. This paper describes a study of the EHD film- forming properties of polyalkylenie glycol lubricants. A wide range of polyglycol structures have been examined, with different monomer types, initiators, and molecular weights. Film thickness has been measured at several different temperatures using both conventional and ultra-thin film interferometry. From the measured film thicknesses, the effective pressure–viscosity coefficients of the lubricants have been evaluated. This has enabled a systematic investigation of the effect of polyalkylene glycol structure on both pressure–viscosity coefficient and EHD film formation.","PeriodicalId":17149,"journal":{"name":"Journal of Synthetic Lubrication","volume":"116 1","pages":"23-45"},"PeriodicalIF":0.0,"publicationDate":"1993-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84069212","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}
Tris(2–octyldodecyl)cyclopentane, prepared by the hydrogenation of the product of alkylation of cyclopentadiene by 2–octyldodecanol, is a wide liquid range hydrocarbon fluid (pour point, −57°C; vapour pressure at 20 °C, 1 × 10−12). This new fluid compares favourably with other hydrocarbons and per fluoropolyethers (PFPAEs) in properties useful for vacuum applications in which low temperature fluidity and low volatility are important properties. It is half the density of PFPAE and exhibits inhibitable oxidation properties similar to other hydrocarbons. The pressure-viscosity coefficient is similar to those of PAOs and PFPAEs.
{"title":"Tris(2-octyldodecyl)cyclopentane, a low volatility, wide liquid range, hydrocarbon fluid","authors":"C. G. Veier, E. W. Casserly, S. Gunsel","doi":"10.1002/JSL.3000090305","DOIUrl":"https://doi.org/10.1002/JSL.3000090305","url":null,"abstract":"Tris(2–octyldodecyl)cyclopentane, prepared by the hydrogenation of the product of alkylation of cyclopentadiene by 2–octyldodecanol, is a wide liquid range hydrocarbon fluid (pour point, −57°C; vapour pressure at 20 °C, 1 × 10−12). This new fluid compares favourably with other hydrocarbons and per fluoropolyethers (PFPAEs) in properties useful for vacuum applications in which low temperature fluidity and low volatility are important properties. It is half the density of PFPAE and exhibits inhibitable oxidation properties similar to other hydrocarbons. The pressure-viscosity coefficient is similar to those of PAOs and PFPAEs.","PeriodicalId":17149,"journal":{"name":"Journal of Synthetic Lubrication","volume":"11 1","pages":"237-252"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81802480","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}
L. J. Gschweder, D. Mattie, C. E. Syder, W. M. Warer, C. V. Brocklin
A chlorotrifluoroethylene (CTFE) based nonflammable hydraulic fluid for use in the −54 °C to 175 °C temperature range has been developed for use in future aircraft and armoured land vehicles to reduce fire losses and improve survivability. The desired flammability, chemical, and physical properties of a non- flammable hydraulic fluid were defined in the 1970s and extensive screening tests were performed to determine the best candidate nonflammable hydraulic fluid basestock. CTFE was selected because it had the best overall properties of all the candidates investigated. Structurelproperty correlation studies were conducted better to understand the behaviour capabilities and limitations of the CTFE basestock. Extensive research and development have been per- formed to develop soluble, effective antiwear and antirust additives to improve some of the critical properties of CTFE. A successful formulation utilising a stabilised zinc, containing corrosion inhibitor and a sulphonamide antiwear additive, has been developed which meets all temperature, lubricity, compatibility, and thermal stability requirements. Research was concurrently conducted to develop elastomers and seals compatible with the CTFE fluid. Several materials have been developed which are usable in somewhat limited applications and Viton GLT has been found to be successful for wide temperature range applications. This paper also discusses toxicity studies and results, environmental effects, future plans and applications, and the current military specification, MIL-H-53119.
{"title":"Chlorotrifluoroethylene oligomer based nonflammable hydraulic fluid. 1 Fluid, additive, and elastomer development","authors":"L. J. Gschweder, D. Mattie, C. E. Syder, W. M. Warer, C. V. Brocklin","doi":"10.1002/JSL.3000090302","DOIUrl":"https://doi.org/10.1002/JSL.3000090302","url":null,"abstract":"A chlorotrifluoroethylene (CTFE) based nonflammable hydraulic fluid for use in the −54 °C to 175 °C temperature range has been developed for use in future aircraft and armoured land vehicles to reduce fire losses and improve survivability. The desired flammability, chemical, and physical properties of a non- flammable hydraulic fluid were defined in the 1970s and extensive screening tests were performed to determine the best candidate nonflammable hydraulic fluid basestock. CTFE was selected because it had the best overall properties of all the candidates investigated. Structurelproperty correlation studies were conducted better to understand the behaviour capabilities and limitations of the CTFE basestock. Extensive research and development have been per- formed to develop soluble, effective antiwear and antirust additives to improve some of the critical properties of CTFE. A successful formulation utilising a stabilised zinc, containing corrosion inhibitor and a sulphonamide antiwear additive, has been developed which meets all temperature, lubricity, compatibility, and thermal stability requirements. Research was concurrently conducted to develop elastomers and seals compatible with the CTFE fluid. Several materials have been developed which are usable in somewhat limited applications and Viton GLT has been found to be successful for wide temperature range applications. This paper also discusses toxicity studies and results, environmental effects, future plans and applications, and the current military specification, MIL-H-53119.","PeriodicalId":17149,"journal":{"name":"Journal of Synthetic Lubrication","volume":"117 1","pages":"187-203"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89223511","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}
The influence of the parameters relating to the rolling elements on traction in EHD contacts is experimentally studied on a two-roller machine, in which experiments with point contacts are conducted for two paraffinic mineral oils, a synthetic naphthene, and a synthetic ester. Firstly, it is shown that the same traction curves are obtained in both internal and external contacts when the effective radius in rolling direction of the rollers is equal. The effect of an increase in the size of the rollers is to increase the film thickness and this results in a gentle decline in the maximum traction coefficient. As the effective radius in transverse direction is increased, so the traction decreases for a paraffinic mineral oil, while that for a synthetic naphthene remains constant independent of the geometry of the rollers. Finally, the effect of the material of the rollers is studied, employing rollers made of steel, ceramics, phosphorus bronze, brass, and aluminium alloy. The traction obtained under an identical normal load can be arranged according to the effective elastic modulus of the rollers for each oil. However, under identical contact pressure the same maximum traction curve is obtained independent of the material, but the decline in traction in the thermal region is slightly steeper with the ceramic than with the steel rollers because of the difference in the temperature rise of the fluid film.
{"title":"Influence of the size, geometry, and material of the rollers on EHD traction","authors":"M. Muraki, K. Sakaguchi","doi":"10.1002/JSL.3000090303","DOIUrl":"https://doi.org/10.1002/JSL.3000090303","url":null,"abstract":"The influence of the parameters relating to the rolling elements on traction in EHD contacts is experimentally studied on a two-roller machine, in which experiments with point contacts are conducted for two paraffinic mineral oils, a synthetic naphthene, and a synthetic ester. Firstly, it is shown that the same traction curves are obtained in both internal and external contacts when the effective radius in rolling direction of the rollers is equal. The effect of an increase in the size of the rollers is to increase the film thickness and this results in a gentle decline in the maximum traction coefficient. As the effective radius in transverse direction is increased, so the traction decreases for a paraffinic mineral oil, while that for a synthetic naphthene remains constant independent of the geometry of the rollers. Finally, the effect of the material of the rollers is studied, employing rollers made of steel, ceramics, phosphorus bronze, brass, and aluminium alloy. The traction obtained under an identical normal load can be arranged according to the effective elastic modulus of the rollers for each oil. However, under identical contact pressure the same maximum traction curve is obtained independent of the material, but the decline in traction in the thermal region is slightly steeper with the ceramic than with the steel rollers because of the difference in the temperature rise of the fluid film.","PeriodicalId":17149,"journal":{"name":"Journal of Synthetic Lubrication","volume":"134 1","pages":"205-221"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73268855","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}
T. Sakai, T. Murakami, Y. Yamamoto, H. Uchiyama, T. Komoto, T. Tezuka
A new type of lubricant, TN, composed mainly of condensed polycyclic naphthenic hydrocarbon rings, was developed from coal tar through a complete hydrogenation process. This oil is characterised by a high pressure-viscosity coefficient and low solidification pressure. The tribological characteristics of this new oil were investigated in an elastohydrodynamic lubrication regime under sliding, rolling/sliding, and rolling contact conditions. The results for the TN oil were compared with those of several oils of different molecular structures: polyalphaolefin of paraffinic hydrocarbon, and naphthenic and paraffinic petroleum oils. It was found that the TN oil was superior to the other oils tested in its ability to form thick oil films, to reduce wear, to increase the coefficient of traction, and to prolong fatigue life.
{"title":"A naphthenic oil of hydrogenated coal tar distil- late as a lubricant with low solidification pressure","authors":"T. Sakai, T. Murakami, Y. Yamamoto, H. Uchiyama, T. Komoto, T. Tezuka","doi":"10.1002/JSL.3000090304","DOIUrl":"https://doi.org/10.1002/JSL.3000090304","url":null,"abstract":"A new type of lubricant, TN, composed mainly of condensed polycyclic naphthenic hydrocarbon rings, was developed from coal tar through a complete hydrogenation process. This oil is characterised by a high pressure-viscosity coefficient and low solidification pressure. \u0000 \u0000 \u0000 \u0000The tribological characteristics of this new oil were investigated in an elastohydrodynamic lubrication regime under sliding, rolling/sliding, and rolling contact conditions. The results for the TN oil were compared with those of several oils of different molecular structures: polyalphaolefin of paraffinic hydrocarbon, and naphthenic and paraffinic petroleum oils. It was found that the TN oil was superior to the other oils tested in its ability to form thick oil films, to reduce wear, to increase the coefficient of traction, and to prolong fatigue life.","PeriodicalId":17149,"journal":{"name":"Journal of Synthetic Lubrication","volume":"12 1","pages":"223-235"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79525700","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}
This paper describes a systematic study into the influence of molecular structure on lubricant shear stress in elastohydrodynamic (EHD) contacts. An infrared emission technique has been employed to measure surface temperatures in an EHD contact and thence to determine the shear stress profile of lubricant films therein. The effect of structure on shear stress has been investigated by comparing the behaviour of a range of well-characterised, closely related, ester base fluids. Considerable variations in shear stress response to EHD conditions have been observed, depending upon the type and structure of the ester.
{"title":"The shear stress properties of ester lubricants in elastohydrodynamic contacts","authors":"H. Chang, H. Spikes, T. F. Bunemann","doi":"10.1002/JSL.3000090202","DOIUrl":"https://doi.org/10.1002/JSL.3000090202","url":null,"abstract":"This paper describes a systematic study into the influence of molecular structure on lubricant shear stress in elastohydrodynamic (EHD) contacts. An infrared emission technique has been employed to measure surface temperatures in an EHD contact and thence to determine the shear stress profile of lubricant films therein. The effect of structure on shear stress has been investigated by comparing the behaviour of a range of well-characterised, closely related, ester base fluids. Considerable variations in shear stress response to EHD conditions have been observed, depending upon the type and structure of the ester.","PeriodicalId":17149,"journal":{"name":"Journal of Synthetic Lubrication","volume":"97 1","pages":"91-114"},"PeriodicalIF":0.0,"publicationDate":"1992-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80723603","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}
Concern at the amount of lubricants lost in the environment has prompted the search for environmentally considerate lubricants, i.e. lubricants which biodegrade as a result of the biological action of living organisms. Various test procedures and parameters are discussed, and the performance of various lubricants, including synthetics, is presented.
{"title":"Environmentally considerate ester lubricants for the automotive and engineering industries","authors":"S. Randles","doi":"10.1002/JSL.3000090205","DOIUrl":"https://doi.org/10.1002/JSL.3000090205","url":null,"abstract":"Concern at the amount of lubricants lost in the environment has prompted the search for environmentally considerate lubricants, i.e. lubricants which biodegrade as a result of the biological action of living organisms. Various test procedures and parameters are discussed, and the performance of various lubricants, including synthetics, is presented.","PeriodicalId":17149,"journal":{"name":"Journal of Synthetic Lubrication","volume":"32 1","pages":"145-161"},"PeriodicalIF":0.0,"publicationDate":"1992-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90064757","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}
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