scholarly journals PREDICTION OF LIFESPAN OF RAILWAY BALLAST AGGREGATE ACCORDING TO MECHANICAL PROPERTIES OF IT

2017 ◽  
Vol 12 (3) ◽  
pp. 203-209 ◽  
Author(s):  
Vaidas Ramūnas ◽  
Audrius Vaitkus ◽  
Alfredas Laurinavičius ◽  
Donatas Čygas ◽  
Aurimas Šiukščius
Keyword(s):  
Mechanical Properties ◽  
Los Angeles ◽  
Static Loading ◽  
Main Criterion ◽  
Railway Ballast ◽  
Los Angeles Abrasion ◽  
Structure Assessment ◽  
The Relationship ◽  
Selection Of

As the railway lifespan is the main criterion for selection of the aggregate for ballast and for planning the maintenance of the railroad, it is important to define the relationship between the particle load resistant characteristics and a lifetime of ballast in structure. Assessment of the quality of the ballast aggregate particles under dynamic and static loading reflect both, the toughness and hardness, and these are identified with the Los Angeles Abrasion and Micro-Deval Abrasion values. The model formerly developed by Canadian Pacific Railroads was adapted to predict possible loads expressed in cumulated tonnes. Different ballast aggregate mixtures were tested in the laboratory including dolomite and granite. Calculated potential gross tonnage (expressed in Million Gross Tonnes) of the railway per lifetime for each different aggregate type presented. The outcome of this research is established classification system of railway ballast aggregate and defined Los Angeles Abrasion and Micro-Deval Abrasion values of aggregate dependently on required lifetime.

scholarly journals EVALUATING THE SAWABILITY OF ROCKS BY CHAIN-SAW MACHINES USING THE PROMETHEE TECHNIQUE

2021 ◽  
Vol 36 (1) ◽  
pp. 25-36
Author(s):  
Reza Mikaeil ◽  
Akbar Esmaeilzadeh ◽  
Sara Aghaei ◽  
Sina Shaffiee Haghshenas ◽  
Amir Jafarpour ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Los Angeles ◽  
Production Rate ◽  
Physical And Mechanical Properties ◽  
Dimension Stone ◽  
Quartz Content ◽  
Los Angeles Abrasion ◽  
Production Values ◽  
Schmidt Hardness ◽  
Dimension Stone Quarry

One of the most significant factors in the estimation of dimension stone quarry cost is the production rate of rock cutting machines. Evaluating the production rate of chain-saw machines is a very significant and practical issue. In this research, it has been attempted to evaluate and select the suitable working-face for a quarry by examining the maximum production rate in the Dehbid and Shayan marble quarries. For this purpose, fi eld studies were carried out which included measuring operational characteristics of the chain-saw cutting machine, the production rate and sampling for laboratory tests from seven active case studies. Subsequently, the physical and mechanical properties of rocks including: Uniaxial Compressive Strength (UCS), Brazilian Tensile Strength (BTS), Los Angeles abrasion, quartz content, water absorption percentage, porosity, Schmidt hardness and grain size for all sample measurements were studied after transferring the samples to a rock-mechanics laboratory. Finally, the sawability of the quarried working-faces was evaluated using the PROMETHEE multi-criteria decision-making (MCDM) model according to the physical and mechanical properties. The results of the study indicated that the number 1 and 5 working-faces from the Dehbid and Shayan quarries are the most suitable working-faces in terms of production rate with the maximum recorded production values (4.95 and 3.1 m2 /h), and with net fl ow rates (2.67 and -0.36) respectively.

Straightening Technology Research of Aluminum Profile for Vehicle

2010 ◽  
Vol 145 ◽  
pp. 449-452
Author(s):  
Jian Jun Hao ◽  
Qing Xue Huang ◽  
Xue Liang Zhang
Keyword(s):  
Process Parameters ◽  
Technology Research ◽  
Aluminum Profile ◽  
The Relationship ◽  
Selection Of

Based on straightening principle of profile straightening equipment, the relationship between process parameters and quality of profile straightening is studied, which can provide basis for optimization and selection of process parameters.

The Relationship Between Microstructure and Mechanical Properties of Late 19th/Early 20th Century Wrought Iron Using the Generalized Method of Cells Model

2002 ◽  
Vol 712 ◽  
Author(s):  
Jennifer J. Hooper ◽  
Lori Graham ◽  
Tim Foecke ◽  
Timothy P. Weihs
Keyword(s):  
Mechanical Properties ◽  
20Th Century ◽  
Mechanical Response ◽  
Early 20Th Century ◽  
Inelastic Behavior ◽  
Silicate Slag ◽  
Wrought Iron ◽  
Generalized Method Of Cells ◽  
The Relationship

ABSTRACTThe discovery of the RMS Titanic has led to a number of scientific studies, one of which addresses the role that the structural materials played in the sinking of the ship. Chemical, microstructural, and mechanical analysis of the hull steel suggests that it was state-of-the-art for 1912 with adequate fracture toughness for the application. However, the quality of the wrought iron rivets may have been an important factor in the opening of the steel plates during flooding. Preliminary studies of Titanic wrought iron rivets revealed an orthotropic, inhomogeneous composite material composed of glassy iron silicate (slag) particles embedded in a ferrite matrix. To date, very little is understood about the properties of wrought iron from that period. Therefore, in order to assess the quality of the Titanic material, contemporary wrought iron was obtained from additional late 19th/early 20th century buildings, bridges, and ships for comparison. Image analysis completed on the Titanic wrought iron microstructure showed a high slag content that is very coarse and unevenly distributed. To investigate how microstructure impacts the mechanical properties, and hence the quality of late 19th/early 20th century wrought iron, a detailed analysis of the relationship between the microstructural features and the mechanical behavior was completed. Here we present the first step in that process: the use of the Generalized Method of Cells (GMC) to predict the mechanical response of composites with variable microstructural properties. The GMC tool is used to generate the effective inelastic behavior of the composite from the individual constituent properties.

A Quantitative Evaluation of the Quality of Recycled Steel in Uganda

2012 ◽  
Author(s):  
C. Senfuka ◽  
J. B. Kirabira ◽  
J. K. Byaruhanga
Keyword(s):  
Mechanical Properties ◽  
Raw Material ◽  
Emission Spectrometry ◽  
Test Results ◽  
Geometrical Properties ◽  
Direct Reduced Iron ◽  
The Relationship ◽  
Recycled Steel ◽  
Made In

All steel made in Uganda is currently manufactured from scrap. Such steel has often been characterized by unpredictable performance in consonance with its inconsistent raw material inputs. This study evaluates and relates the mechanical, metallurgical and geometrical properties of these bars in order to identify the factors underlying the performance of the products from this steel and examine the relationship with their scrap content. In order to study the steels, tensile, torsion and micrographic tests have been carried out together with spark emission spectrometry on samples collected from different plants. The test results generally indicate impressive steel resilience, strength and metallographic properties in spite of relatively high and irregular carbon content. Limited weldability, uniaxiality of properties, uneven scatter of microelements and substantial non-uniformity of longitudinal mechanical properties have been observed. Rolling and post rolling defects have been noted. The geometric reliability of the bars has also been found generally low. Improvement of secondary refinement, use of direct reduced iron (DRI) diluent and more diligent sorting have suggested as solutions.

Method of Testing the Mechanical Properties of Vulcanizates Prepared from Latex as a Starting Material

1948 ◽  
Vol 21 (1) ◽  
pp. 168-179
Author(s):  
Marcel Pirot
Keyword(s):  
Mechanical Properties ◽  
Starting Material ◽  
Daily Production ◽  
Selection Of

Abstract With the method which has been described, it is possible to obtain reproducible results easily. It is hoped that the method will make it easier to study the properties of rubber mixtures prepared from latex. Furthermore the quantity of a latex mixture needed for such a test is small, i.e., of the order of 400 cc., so the method is particularly well adapted to the selection of Hevea trees on a basis of the quality of their latex. As a matter of fact, it will be easy in many cases to follow the collection of latex from a limited number of trees. It should even be possible, by using a single dipping form and reducing the size of the dipping tank, to follow the quality of the latex from the daily production of one tree, a procedure which is impossible with coagulated rubber.

scholarly journals Mechanical Properties of GFR & Graphite Epoxy Polymer Composites

2020 ◽  
Vol 5 (6) ◽  
pp. 560-565
Author(s):  
A. Aakash ◽  
S. Selvaraj
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Composite Materials ◽  
Polymer Composite ◽  
Epoxy Polymer ◽  
Significant Degree ◽  
Polymer Composite Material ◽  
Water Ingestion ◽  
Selection Of

Composite materials have the great potential and widely used as building material in numerous applications. Polymer composite material obtains the necessary properties in a controlled significant degree by the selection of strands and lattice. The properties of the materials have been selected by choosing the correct proportion of matrix and reinforcements. To build the quality of the material by expanding the fiber substance of the material. In this current examination, the mechanical properties of the glass fiber and graphite is strengthened with epoxy polymer composite were considered. Here the open embellishment method was received for the manufacture of the polymer composite The mechanical properties, for example, rigidity, compression quality, sway quality and water ingestion test was resolved according to the ASTM norms. The mechanical properties were improved as the filaments support content expanded in the grid material.

scholarly journals Evaluation of gravel for concrete and road aggregates, Rapti River, Central Nepal Sub-Himalaya

1970 ◽  
Vol 10 ◽  
pp. 99-106 ◽  
Author(s):  
Surendra Maharjan ◽  
Naresh Kazi Tamrakar
Keyword(s):  
Los Angeles ◽  
Chemical Weathering ◽  
Effective Porosity ◽  
Raw Material ◽  
British Standard Institution ◽  
Dry Density ◽  
Carbonate Group ◽  
British Standard ◽  
Los Angeles Abrasion

Several local mining sites of sand and gravel have been operating for decades in the Rapti River. River gravels are consumed in Hetauda, Narayanghad and areas in India near the border between Nepal and India. Until now little known about consumers concerning about quality of gravel. The present study was carried out to evaluate quality of river gravel to know its suitability for aggregate (raw material for concrete and road). The samples of river gravel were analysed for petrographic, physical, mechanical and chemical properties. Samples were categorised as quartzite group, carbonate group and granite group according to British Standard Institution (BSI). Among these, samples of quartzite group were found dominant. Image analysis of gravel showed that clasts were well graded. The majority of the samples had rounded, high sphericity and oblate triaxial clasts. The surface texture of clasts was rough to smooth. In terms of shape, workability of gravel was satisfactory. Gravel samples possessed low water absorption value (0.69 to 1.12%) and low effective porosity. Dry density of samples ranged from 2460 to 2680 kg/m3. Aggregate impact values of samples (14.2 to 16.1%) showed good soundness. Los Angeles abrasion test also showed consistent hardness of each of the samples as uniformity factor did not exceed 0.2. Magnesium sulphate values ranged between 4.46% and 7.29% suggesting good resistance against chemical weathering and frosting. Comparing with the existing Nepal Standard, British Standard and American Standard of Testing Material, the studied samples were suitable for concrete and road aggregates.   doi: 10.3126/bdg.v10i0.1425      Bulletin of the Department of Geology, Tribhuvan University, Kathmandu, Nepal, Vol. 10, 2007, pp. 99-106

scholarly journals Governing Territories in Turbulence with Advanced Marketing Frameworks

2020 ◽  
Vol 16 (1) ◽  
pp. 79
Author(s):  
Roberto Bruni ◽  
Annarita Colamatteo ◽  
Evgenia Nekhoda
Keyword(s):  
Technology Use ◽  
Policy Makers ◽  
Use Of Data ◽  
Production And Consumption ◽  
External Stakeholders ◽  
Design Production ◽  
The Relationship ◽  
Selection Of

The world is living in a period of turbulence in terms of health and environmental emergencies, markets and societies complexity. Providing sustainable wellbeing and quality of life to population is a challenge for governments. Policy makers are searching for useful strategies to satisfying the needs of population, and forecasting problems for the future. Technology, use of data, international cooperation and networks are change-generating forces that cause effects on markets and societies and modify the design, production, and consumption of products and services. Companies manage the factors that stimulate the change, modifying or adapting their management and marketing approaches. The challenge of managing turbulence of societies and the relationship with internal and external stakeholders appears to be more difficult for governments. Including literature from sociology, geography, and business and management, a selection of multidisciplinary contributions is presented to explain the role of advanced marketing frameworks appliable by governments to overcome the complexity within territories caused by the change-generating forces. The paper presents the place marketing ‘value co-creation driven’ as a useful framework to manage the place value proposition by governments, using specific capabilities and a systemic approach.

Dyeing and Mechanical Properties of Cotton Modified for Cationic Dyes with Hydrophobic and Acidic Groups

1992 ◽  
Vol 62 (3) ◽  
pp. 135-139 ◽  
Author(s):  
Kazuhiko Fukatsu
Keyword(s):  
Mechanical Properties ◽  
General Trend ◽  
Breaking Load ◽  
Cationic Dyes ◽  
Superior Performance ◽  
Chemically Modified ◽  
Basic Studies ◽  
The Relationship ◽  
Sulfonic Acid Groups ◽  
Selection Of

Basic studies define the relationship between dyeability for cationic dyes and mechanical properties of chemically modified cotton fabric. Introduction of benzoyl and sulfonic acid groups provides either satisfactory dyeability for cationic dyes or color-fastness, and mechanical properties are reported as a function of the benzoate degree of substitution value. The general trend is toward increased breaking load and bending stiffness and decreased wrinkle recovery for the chemically modified fabrics, but within this trend there is latitude for selection of the degree of substituent groups to provide superior performance.

Sign in / Sign up

Export Citation Format

Share Document