Retraction and Stress Propagation in Natural and Synthetic Gum and Tread Stocks

1945 ◽  
Vol 18 (3) ◽  
pp. 557-578
Author(s):  
B. A. Mrowca ◽  
S. L. Dart ◽  
Eugene Guth

Abstract Natural and synthetic rubbers (elastomers) are characterized by their long-range reversible elasticity. More particularly, the existence of a retractive force distinguishes rubbers from materials like beeswax, which may be extended but do not snap back. Whereas all rubbers show a snapback, the good rubbers show a fast snapback. Thus the speed of snapback is an outstanding index to the quality of the rubber. For instance, both Hevea and Butyl show snapback, but Butyl snaps back much more slowly than Hevea. This is the reason for the poor rebound in Butyl. Incidentally, the speed of snapback may be, and actually is, used as a simple “hand test” for progress of cure. One bends a cured sheet and observes how fast it straightens out again. In this example the speed of recovery after bending is observed. The speed of snapback may be studied, of course, for any deformation : bending, torsion, shear, compression, extension, etc. Since stress-strain data are used so extensively in rubber technology, snapback after extension was studied first. Snapback will be used in this restricted sense in the following text. Besides characterizing the quality of a polymer, the speed of snapback is of great direct importance for tire construction. Sluggish snapback may lead to increased flexing, i.e., increased heat generation. In addition, slow snapback means less grip of the tire on the road, assuming equal wetting conditions.

2020 ◽  
Vol 7 (1) ◽  
pp. 99
Author(s):  
Yong Adilah Shamsul Harumain ◽  
Nur Farhana Azmi ◽  
Suhaini Yusoff

Transit stations are generally well known as nodes of spaces where percentage of people walking are relatively high. The issue is do more planning is actually given to create walkability. Creating walking led transit stations involves planning of walking distance, providing facilities like pathways, toilets, seating and lighting. On the other hand, creating walking led transit station for women uncover a new epitome. Walking becomes one of the most important forms of mobility for women in developing countries nowadays. Encouraging women to use public transportation is not just about another effort to promote the use of public transportation but also another great endeavour to reduce numbers of traffic on the road. This also means, creating an effort to control accidents rate, reducing carbon emission, improving health and eventually, developing the quality of life. Hence, in this paper, we sought first to find out the factors that motivate women to walk at transit stations in Malaysia. A questionnaire survey with 562 female user of Light Railway Transit (LRT) was conducted at LRT stations along Kelana Jaya Line. Both built and non-built environment characteristics, particularly distance, safety and facilities were found as factors that are consistently associated with women walkability. With these findings, the paper highlights the criteria  which are needed to create and make betterment of transit stations not just for women but also for walkability in general.


Medical Care ◽  
2008 ◽  
Vol 46 (8) ◽  
pp. 759-761 ◽  
Author(s):  
Jeanne S. Mandelblatt ◽  
Arnold L. Potosky

2019 ◽  
Vol 4 (2) ◽  
pp. 1
Author(s):  
Elisawati Elisawati ◽  
Deasy Wahyuni ◽  
Adi Arianto

The order of traffic on the road is very important for motorists on the highway, the lack of awareness of motor vehicle users and the poor drivers of traffic discipline make the level of traffic violations in driving on the highway always increase so that the number of ticket data received by the Dumai District Court. This research was conducted to analyze and classify data violations using the k-means method to facilitate knowing the types of violations that are often violated by vehicle users. The attributes to be analyzed are the types of violations and types of vehicles. The test was carried out using the Rapidminer 5 application where the data tested was data from the Dumai District Court on December 2017, as many as 616 violations. Central cluster data consists of 3 clusters, namely C1 = Many, C2 = moderate and C3 = few who commit traffic violations. So the results of the data obtained where C1 produces 1 data, C2 gets as much as 4 data and C3 as many as 7 data. Where the type of violation that is often violated is the type of violation that does not use a helmet and the type of vehicle is a motorcycle. From the results of this study can be used or can be followed up with the holding of socialization to reduce the number of traffic violations. Keywords: Clustering Analysis, K-Means, Traffic Violations, Rapidminer


2021 ◽  
Vol 297 ◽  
pp. 01019
Author(s):  
Abdeslam Houari ◽  
Tomader Mazri

6G of mobile networks plays a crucial role in improving the capacity and enhancing the quality of services of Vehicle-to-Everything (V2X) based networks evolving in an intelligent environment. VANET is a promising project in the intelligent transportation field using V2X communications. The emergence of several 5G and 6G technologies has raised several challenges for scientists and researchers to allow vehicles and road users to enjoy several services while ensuring their safety on the road. Among these technologies, the unmanned aerial vehicle (UAV), which can perform different tasks for road users and vehicle drivers such as data caching, packet relaying and processing. In this article, we present a new approach based on 6G Unmanned Aerial Vehicles (UAV) technology on a vehicular cloud architecture while exploiting the exchange support of information-centric networking (ICN) for the improvement of network capacity.


Author(s):  
Markus Mailer

This chapter presents a multi-modal method for the assessment of highway performance. It is derived by extending a traditional assessment concept step by step taking into account the capacity and quality of different modes on the road as well as in the corridor. It defines an appropriate performance target and explains why a multi-modal concept has to consider transport demand in persons and goods rather than traffic volumes in vehicle units. It is shown that the concept allows for different options and measures to improve traffic quality and so supports the efficient use of existing infrastructure and the effective allocation of limited funds.


2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Nathan J. Wilson ◽  
Hoe C. Lee ◽  
Sharmila Vaz ◽  
Priscilla Vindin ◽  
Reinie Cordier

Gaining a driver’s licence represents increased independence and can lead to improved quality of life for individuals and their families. Learning to drive a motor vehicle and maintaining safe on-road skills are often more difficult for people on the autism spectrum. Many countries currently have no autism-specific licencing requirements for learner drivers, and there is a general lack of ASD-specific support and training packages for individuals, their families, and driving instructors. This review synthesises the peer-reviewed literature about the driving characteristics of drivers on the spectrum and driver training available for the cohort. The evidence in this review showed that individuals on the autism spectrum drive differently from their neurotypical counterparts. There are shortcomings in tactical skills of drivers on the autism spectrum, but the extent to which this affects their own safety or the safety of other road users is unclear. Tactical skills can be improved through training programs. There are few autism spectrum-specific learner training programs available. Development of an effective training program will benefit individuals on the spectrum to learn to drive, be independent, and be safe on the road.


Author(s):  
Danuta Rucińska ◽  
Małgorzata Kędzior-Laskowska

This article aims to identify determinants which influence the quality of service on the road freight market. In doing so it focuses on five aspects of carrier activity within the said market, namely the processes leading to the internationalization of operations, innovative mechanisms and technological solutions dedicated to this branch, as well as the formal, legal, economical, and ecological conditions involved. During the course of study the above mentioned factors were subjected to the evaluation of the carriers. The article presents the results of the said study and identifies the most important aspects which, according to the respondents, play a vital role in influencing the quality of services they offer. The study was conducted by way of both in-person and telephone interviews.


2021 ◽  
Vol 6 (166) ◽  
pp. 130-133
Author(s):  
H. Sarkisian ◽  
V. Tymoshevskyi ◽  
S. Urdzik

Most of the transport and operational indicators that directly affect the road roughness depend on the roughness of coverage. Therefore, the control and timely monitoring of the road roughness is an extremely important issue that needs the attention of road maintenance services. At monitoring of the road roughness it is most expedient to use a technique of leveling of a covering. The method of leveling the coating provides more detailed information about the coating and allows you to determine the smallest deformations on the road coating, which may be at the first stage of their development, especially at that stage of their development, and show roughness and various parameters. One of the main tasks of measurements in the process of performing geodetic works is not only to obtain the measurement result, but also to assess its reliability. The required quality of instrumental measurement can not be achieved without adhering to the principles of unity and the required accuracy of measurements, so much attention should be paid to the metrological support of geodetic works. The purpose of this article is to analyze the metrological support of geodetic works in determining the pavement roughness and substantiation of the required accuracy of measuring the non-rigid pavement roughness. On the basis of dependences for determining the coefficient of dynamic load on pavement and the correlation between the pavement roughness and the coefficient of dynamic load and on the basis of experimental data, the necessary accuracy of measuring the non-rigid pavement roughness is substantiated. Based on the analysis, it was found that the accuracy of determining the height of the irregularities should not exceed 0.5 mm, for which it is necessary to use optical or electron-optical levels.


Jurnal CIVILA ◽  
2018 ◽  
Vol 3 (2) ◽  
pp. 154
Author(s):  
Errine Yulia Rizqi Intanti ◽  
Zulkifli Lubis

In Indonesia, the road construction has experienced a fairly good development. From a wide range of road constructions, flexible pavement is the most chosen one because its characteristics: easy, fast, and efficient. However, flexible pavement has many weaknesses, for example the premature damage on the road surface after some time passed by the traffic so that the road cannot reach the planned age. For that, it is done a research to add a hot asphalt mixture material that aims to improve the quality of the mixture results. The selected ingredient is natural water hyacinth. The method used is trial and error with reference of SNI 03-1737-1989. Variations used are 2%, 4%, 6%, 8% and 10% of the asphalt weight, asphalt level used is 5.72 %. Of the 5 variations of mixture used on Type XI Asphalt Concrete Layer, it is obtained the result that the water hyacinth fiber level which has the best score and meet the specifications of SNI 03-1737-1989 is on the percentage of 6% which obtained from calculation data using graphs and regression model where Marshall Stability is equal to 644,46 Kg, flow 3,39 mm, VMA (voids in the mineral aggregate) is equal to 13,83 %, VFWA (voids filled with asphalt) is equal to 65,35%, VIM (voids in the mix) is equal to 2,52 %, density of 2.31 gr/cc, and Marshall Quotient of 164.03 Kg / mm.


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