Tread Wear and Wet Skid Resistance of Butadiene-Styrene Elastomers and Blends

1971 ◽  
Vol 44 (4) ◽  
pp. 996-1014 ◽  
Author(s):  
R. N. Kienle ◽  
E. S. Dizon ◽  
T. J. Brett ◽  
C. F. Eckert
Keyword(s):  
Viscoelastic Properties ◽  
Combined Effect ◽  
Wear Loss ◽  
Skid Resistance ◽  
Wear Factor ◽  
Factors Affecting ◽  
Material Factor ◽  
Relationship Of ◽  
Wet Skid Resistance ◽  
Butadiene Styrene

Abstract 1. Car, wheel position, driver, inflation pressure, and shoulder drop have a statistically significant effect upon wear loss and need to bo taken into consideration before material factors affecting wear can be studied. 2. Variations in macrostructure of the polymers are not found to have a significant effect on wear as compared to microstructure variations. 3. At least two material factors control wear loss of tire treads. 4. When polymers are tested near their glass transition temperature (within 80° C), wear loss is dominated by viscoelastic properties. Viscoelastic properties can be related to wear loss through Tg or the combined effect of the cis, trans, vinyl, and styrene content. 5. At higher test temperatures (over 100° C above Tg) wear loss is dominated by a material factor that has a positive correlation with temperature. This is particularly noticeable when treads are worn under mild conditions. However, there is evidence that this wear factor is present at the testing nearer to Tg but is masked by the dominant viscoelastic effect. 6. The combined effect upon wear of the different material factors leads to an optimum wear resistance for any polymer in the butadiene—styrene system in the range of 75°–105° C above the Tg for that polymer. 7. For polymers tested at the same ambient temperature, (T), the effect of viscoelastic properties decreases non-linearly as T−Tg increases. 8. In the range of test severity studied, severity has little effect upon the inter-relationship of material factors. 9. In the range of test temperature where Tg dominates wear loss, skid distance on wet asphalt pavement is inversely related to wear rating.

Relationships Between the Friction and Viscoelastic Properties of Rubber

2000 ◽  
Vol 28 (3) ◽  
pp. 178-195 ◽  
Author(s):  
N. Amino ◽  
Y. Uchiyama
Keyword(s):  
Viscoelastic Properties ◽  
Skid Resistance ◽  
Grain Sizes ◽  
Abrasive Grain ◽  
The Coefficient Of Friction ◽  
Tan Δ ◽  
Silicone Carbide ◽  
And Storage ◽  
Wet Skid Resistance ◽  
Frequency Curves

Abstract In this study, the relationships between friction and viscoelastic properties such as loss tangent tan δ and storage modulusE′ were examined. Wet skid resistance was measured using the British Pendulum Tester. The rubber specimens were rubbed againstfive silicone carbide cloths of differing abrasive grain sizes. The viscoelastic properties of the rubber specimens were measured with a viscoelasticspectrometer. From the data on wet skid resistance and viscoelastic properties, it is found that the coefficient of friction μ varies as follows:           μ = a + b · tan δ/E′ where a and b are constants. Tan δ/E′ was related to the hysteresis term of friction, and the μ-frequency curves were compared with the tan δ/E′ –frequency curves.

Effects of Carbon Black and Process Oil on Viscoelastic Properties and Tire Wet Skid Resistance

1998 ◽  
Vol 26 (4) ◽  
pp. 241-257 ◽  
Author(s):  
H. Takino ◽  
H. Takahashi ◽  
K. Yamano ◽  
S. Kohjiya
Keyword(s):  
Carbon Black ◽  
Viscoelastic Properties ◽  
Hysteresis Loss ◽  
Poor Correlation ◽  
Skid Resistance ◽  
Good Relationship ◽  
Rubber Friction ◽  
Wide Range ◽  
Tan Δ ◽  
Wet Skid Resistance

Abstract Wet skid resistance for rubbers with a wide range of carbon black loadings and process oil loadings was investigated from the viewpoints of viscoelastic properties and abrasion properties. An analysis of wet skid resistance by the factors of Tα and BPST abrasion, which was effectively performed on a wide range of polymers in a previous report, gave a poor correlation this time. In the case of a wide range of carbon black loadings and oil loadings, the factors of tan δ and BPST abrasion had a good relationship with wet skid resistance. In this study, tan δ at 7°C was found to be a suitable factor corresponding to adhesion loss and hysteresis loss in rubber friction. By the evaluation of abrasions, BPST abrasion and PICO abrasion were estimated to be governed by different mechanisms.

Viscoelastic Properties of Elastomers and Tire Wet Skid Resistance

1997 ◽  
Vol 70 (4) ◽  
pp. 584-594 ◽  
Author(s):  
H. Takino ◽  
R. Nakayama ◽  
Y. Yamada ◽  
S. Kohjiya ◽  
T. Matsuo
Keyword(s):  
Systems Analysis ◽  
Viscoelastic Properties ◽  
Skid Resistance ◽  
Polymer Systems ◽  
The Past ◽  
Rubber Friction ◽  
Wide Range ◽  
Tan Δ ◽  
Peak Value ◽  
Wet Skid Resistance

Abstract Many studies concerning tire wet skid resistance have been published in the past, but they have in general involved the use of only a few grades of SBR and BR. We have evaluated the British Portable Skid Tester (BPST) wet skid resistance of eighteen sulfur curable polymers which might be used for automobile tires. These results have been analyzed in relation to the viscoelastic properties of the polymer systems. Analysis of wet skid resistance in terms of the peak value of tan δ over a prescribed temperature range, designated as Tα, and abrasion loss—derived from the theory of rubber friction—was concluded to give a better general relationship for a wide range of polymers.

scholarly journals 86 Factors affecting beef calf vigor at birth: Dam peripartum body condition score, calving season, and calf size

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 3-3
Author(s):  
Lindsey G Wichman ◽  
Colby A Redifer ◽  
Natalie B Duncan ◽  
Craig A Payne ◽  
Allison M Meyer
Keyword(s):  
Mixed Model ◽  
Body Condition Score ◽  
Negative Relationship ◽  
Beef Cows ◽  
Abdominal Girth ◽  
Factors Affecting ◽  
Condition Score ◽  
Calving Season ◽  
Relationship Of ◽  
The Relationship

Abstract To determine effects of cow BCS and calving season on calf vigor and size and the relationship of calf size with vigor, 310 multiparous and primiparous beef cows (age: 4.6 ± 2.2 yr; BW: 663 ± 86 kg; BCS: 5.3 ± 0.6) from 3 spring (2015, 2016, 2017) and 4 fall (2015, 2017, 2018, 2019) calving seasons were observed during parturition. Time to stand (n = 191) was determined as minutes from birth to standing successfully for 5 sec. Within 24 h, calf BW (n = 187) and size [shoulder to tailhead length (STL), heart girth (HG), and abdominal girth (AG; n = 154)] were recorded. Data were analyzed using a mixed model containing effects of calving season (spring and fall), BCS category (< 5, =5, ≥6), and their interaction. Correlations were determined between time to stand and calf measurements separately for spring (n = 79) versus fall (n = 111). Cows with BCS < 5 gave birth to lighter (P = 0.02) calves that tended to have a faster (P ≤ 0.13) time to stand than =5 and ≥6. Calves from cows with BCS ≥6 tended to have greater (P ≤ 0.09) STL than =5 and < 5. Calves from cows with BCS < 5 had smaller (P = 0.13) HG than =5. Fall-born calves tended to have smaller (P ≤ 0.06) BW, HG, and AG than spring-born calves. Within fall calves, there tended to be a positive relationship (r = 0.16; P = 0.09) between time to stand and calf BW. Despite this, spring calves had a negative relationship (r = -0.26; P = 0.02) between time to stand and calf BW. In conclusion, cow BCS and calving season affect calf size and may affect calf vigor. These data suggest that calving season may dictate the relationship between calf vigor and size.

scholarly journals Analysis of Internal and External Determinant Variables towards Profitability of Islamic Banking in Indonesia (2014-2020)

2021 ◽  
Vol 4 (1) ◽  
pp. 18-34
Author(s):  
Febri Ramadhani ◽  
Muhammad Rizkan
Keyword(s):  
Negative Relationship ◽  
Banking System ◽  
Islamic Banking ◽  
Correction Model ◽  
Factors Affecting ◽  
Vector Error Correction ◽  
Vector Error ◽  
Long Run ◽  
Short Run ◽  
Relationship Of

Indonesia is a country that adheres to a dual banking system, namely conventional and Islamic Banking. The growth rate of Islamic banking in the last three years is higher than conventional banking. However, in total assets, Islamic banking is still far behind conventional banking. Therefore, it is necessary to study further the performance of Islamic banking reflected in its profitability. So, it becomes an alternative input in determining Islamic banking policies. This study aims to know the factors affecting the profitability (ROA) of Islamic Banking in Indonesia. The data used are the 2014-2020 monthly data in the amount of 79 data. The method used in this study is a Vector Error Correction Model (VECM) to determine the effect of long-run and short-run relationships. The results of the study showed that the long-run relationship of the NPF variable affected and was significant positive toward ROA, CAR affected and was significant negative toward ROA, while the inflation variable had a negative relationship and not significant toward ROA. The results of the short-run relationships showed that the NPF and CAR variables positively affected ROA, while the inflation variable did not significantly affect the ROA.

scholarly journals The Impacts of Flowering Time and Tillering on Grain Yield of Sorghum Hybrids across Diverse Environments

2019 ◽  
Author(s):  
Xuemin Wang ◽  
Colleen Hunt ◽  
Alan Cruickshank ◽  
Emma Mace ◽  
Graeme Hammer ◽  
...  
Keyword(s):  
Grain Yield ◽  
Flowering Time ◽  
Genetic Background ◽  
Linear Models ◽  
Genetic Correlations ◽  
Environment Interaction ◽  
Canopy Development ◽  
Factors Affecting ◽  
Sorghum Production ◽  
Relationship Of

Sorghum in Australia is grown in water-limited environments of varying extent, generating substantial genotype × environment interaction (GEI). Much of the yield variation and GEI results from variations in flowering time and tillering through their effects on canopy development. The confounding effects of flowering and tillering complicate the interpretation of breeding trials. In this study, we evaluated the impacts of both flowering time (DTF) and tillering capacity (FTN) on yield of 1741 unique test hybrids derived from three common female testers in 21 yield testing trials (48 tester/trial combinations) across the major sorghum production regions in Australia in three seasons. Contributions of DTF and FTN to genetic variation in grain yield were significant in 14 and 12 tester/trial combinations, respectively. The proportion of genetic variance in grain yield explained by DTF and FTN ranged from 0.2% to 61.0% and from 1.4% to 56.9%, respectively, depending on trials and genetic background of female testers. The relationship of DTF or FTN with grain yield of hybrids was frequently positive, but varied across the genetic background of testers. Accounting for the effects of DTF and FTN using linear models did not substantially increase the between trial genetic correlations for grain yield. The results suggested that other factors affecting canopy development dynamics and grain yield might contribute GEI and/or the linear approach to account for DTF and FTN on grain yield did not capture the complex non-linear interactions.

scholarly journals Theoretical and Methodological Approaches to Tourism Enterprise Business Processes Efficiency Evaluation

2020 ◽  
Vol 7 (2) ◽  
pp. 22-30
Author(s):  
Yuriy B. Myronov ◽  
Mariana I. Myronova
Keyword(s):  
Business Processes ◽  
Tourism Industry ◽  
Green Technologies ◽  
Factors Affecting ◽  
Performance Targets ◽  
Analysis And Synthesis ◽  
Virtual And Augmented Reality ◽  
Methodological Approaches ◽  
Tourism Enterprises ◽  
Relationship Of

The relevance of the research is stipulated by the necessity for an adequate evaluation of the tourism enterprises’ efficiency and individual business processes at these enterprises in the context of the ever-growing influence of the tourism industry on the economic and social spheres of society. The aim of the research is to build a conceptual model for evaluating the efficiency of business processes of tourist enterprises. The methodological basis of the research is based on methods of abstraction, analogies, analysis and synthesis; normative and positive approaches to the study of economic processes; process and system approaches; modelling method. The article considers theoretical and methodological approaches to assessing the efficiency of tourism enterprise processes in modern conditions of tourism services market development. The main concepts of business processes were defined, the goal and criteria for evaluating their efficiency were formulated. The main factors affecting the efficiency of tourism enterprises business processes were described. The main groups of indicators for evaluating the tourism enterprise business processes efficiency were proposed. Such a system of indicators helps to comprehensively monitor the situation at a tourism enterprise, since it takes into account all key areas of activity of an enterprise and identifies priority business processes that require changes. The specifics of assessing the level the efficiency of tourism enterprises business processes depend on a number of variable factors and therefore the main trends in the development of a tourist enterprise and the relationship of its economic indicators are usually studied. Approaches to the procedure for evaluating the efficiency of business processes, as well as to the formation of a system of indicators for evaluating the specified efficiency at a tourism enterprise were studied. The main principles of forming a system for evaluating tourism enterprises business processes efficiency are defined. A number of technologies for evaluating the efficiency of business processes were described. A model for evaluating the efficiency of business processes in tourism is presented. It is noted that the main and determining role in evaluating the activities of a tourism enterprise is played by performance targets. Based on the identified features of tourism activities, problems that may arise in the process of evaluating the efficiency of business processes were considered and effective ways to eliminate them were proposed. The prospects for further scientific researches in this direction are substantiated, which are to study the improvement of the tourism companies efficiency through the introduction of innovative technologies (neuromarketing, virtual and augmented reality, as well as “green” technologies)

scholarly journals A STUDY OF FACTORS AFFECTING THE FLUIDITY OF CEMENT

2019 ◽  
pp. 8-16
Author(s):  
Л. Шахова ◽  
L. Shakhova ◽  
Е. Черноситова ◽  
E. Chernositova ◽  
Л. Щелокова ◽  
...  
Keyword(s):  
Labor Costs ◽  
Factors Affecting ◽  
Correlation And Regression Analysis ◽  
Cement Powder ◽  
Production Factors ◽  
Variable Factor ◽  
Cement Binder ◽  
Cement Grinding ◽  
Relationship Of ◽  
The Relationship

The fluidity of cement powder has a significant impact on the duration and labor costs in the process of transportation and shipment of cement. This determines the relevance of the task of finding mechanisms to control this parameter. During the production process, the fluidity of the cement powder is formed depending on the properties of the initial cement charge, the requirements for the thinness of the grinding to the finished product, the hardware design and the conditions of the process. In turn, the fluidity of cement affects the grinding process and the productivity of the mill. The rheological characteristics of the cement binder change over time depending on the physical properties of the material, environmental conditions and the equipment used for its storage. The reasons for the deterioration of the flow of cement powder is still not fully studied. The article is devoted to the study of the main factors affecting the fluidity of cement. The results of the statistical analysis of cement fluidity depending on the thinness of cement grinding (on the residue on the sieve №008 and the specific surface area by Blaine method) humidity, bulk weight and weight in the most compacted state. In addition, the relationship of production factors and cement fluidity is considered. Correlation and regression analysis shows that the fluidity is affected by a variable factor, which is not yet quantified.

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