Pyrolysis of waste tyres: a review.

Science.gov (United States)

Williams, Paul T

2013-08-01

Approximately 1.5 billion tyres are produced each year which will eventually enter the waste stream representing a major potential waste and environmental problem. However, there is growing interest in pyrolysis as a technology to treat tyres to produce valuable oil, char and gas products. The most common reactors used are fixed-bed (batch), screw kiln, rotary kiln, vacuum and fluidised-bed. The key influence on the product yield, and gas and oil composition, is the type of reactor used which in turn determines the temperature and heating rate. Tyre pyrolysis oil is chemically very complex containing aliphatic, aromatic, hetero-atom and polar fractions. The fuel characteristics of the tyre oil shows that it is similar to a gas oil or light fuel oil and has been successfully combusted in test furnaces and engines. The main gases produced from the pyrolysis of waste tyres are H(2), C(1)-C(4) hydrocarbons, CO(2), CO and H(2)S. Upgrading tyre pyrolysis products to high value products has concentrated on char upgrading to higher quality carbon black and to activated carbon. The use of catalysts to upgrade the oil to a aromatic-rich chemical feedstock or the production of hydrogen from waste tyres has also been reported. Examples of commercial and semi-commercial scale tyre pyrolysis systems show that small scale batch reactors and continuous rotary kiln reactors have been developed to commercial scale. Copyright © 2013 Elsevier Ltd. All rights reserved.

Experimental investigations on a diesel engine operated with fuel blends derived from a mixture of Pakistani waste tyre oil and waste soybean oil biodiesel.

Science.gov (United States)

Qasim, Muhammad; Ansari, Tariq Mahmood; Hussain, Mazhar

2017-10-18

The waste tyre and waste cooking oils have a great potential to be used as alternative fuels for diesel engines. The aim of this study was to convert light fractions of pyrolysis oil derived from Pakistani waste vehicle tyres and waste soybean oil methyl esters into valuable fuel and to reduce waste disposal-associated environmental problems. In this study, the waste tyre pyrolysis liquid (light fraction) was collected from commercial tyre pyrolysis plant and biodiesel was prepared from waste soybean oil. The fuel blends (FMWO10, FMWO20, FMWO30, FMWO40 and FMWO50) were prepared from a 30:70 mixture of waste tyre pyrolysis liquid and waste soybean oil methyl esters with different proportions of mineral diesel. The mixture was named as the fuel mixture of waste oils (FMWO). FT-IR analysis of the fuel mixture was carried out using ALPHA FT-IR spectrometer. Experimental investigations on a diesel engine were carried out with various FMWO blends. It was observed that the engine fuel consumption was marginally increased and brake thermal efficiency was marginally decreased with FMWO fuel blends. FMWO10 has shown lowest NOx emissions among all the fuel blends tested. In addition, HC, CO and smoke emissions were noticeably decreased by 3.1-15.6%, 16.5-33.2%, and 1.8-4.5%, respectively, in comparison to diesel fuel, thereby qualifying the blends to be used as alternative fuel for diesel engines.

Development of the tyre tester

CSIR Research Space (South Africa)

Kuduntwane, P

2012-10-01

Full Text Available of the tyre tester P KUDUNTWANE1, DU PLESSIS2 AND PROF. S ELS3 1CSIR Defence, Peace, Safety and Security, PO Box 395, Pretoria, South Africa, 0001 2Department of Mechanical Engineering, Central University of Technology, Private Bag X20539, Bloemfontein...

Effects of moving dynamic tyre loads on tyre-pavement contact stresses

CSIR Research Space (South Africa)

Steyn, WJvdM

2002-01-01

Full Text Available The purpose of this paper is to indicate the effect that moving dynamic tyre loads has on the tyre-pavement contact stresses used in pavement analysis. Traditionally tyre loads (in pavement analysis) are modelled as constant loads applied through...

Dedicated tyre characterization

NARCIS (Netherlands)

Lupker, H.A.; Vis, M.A.; Schmeitz, A.J.C.

2000-01-01

A pneumatic tyre is an extremely complex system designed to form a suitable compromise for many design requirements. The variety of phenomena to be studied makes it necessary to characterise tyres in various ways. This paper focuses on empirical and physical tyre models for passenger car

a Study of Radial Vibrations of a Rolling Tyre for TYRE-ROAD Noise Characterisation

Science.gov (United States)

Périsse, J.

2002-11-01

Because tyre-road noise represents the main noise source for light vehicles with driving speed above 60 km/h, comprehension of generation mechanism of tyre-road noise has become a subject of major importance. In this paper, tyre-road interaction and radial tyre vibrations are investigated for tyre-road noise characterisation. Experimental measurements are performed on a rolling smooth tyre with test laboratory facilities. Both tread band and sidewall responses of the tyre are measured and compared to each other. High concentration of vibrations is observed in the vicinity of the contact area. Stationary radial deformation and non-stationary vibrations due to road rugosity are studied. Frequency analyses have been performed on the acceleration time signals showing the influence of the rotating speed on the vibrations level and frequency content. Finally, by integrating acceleration signal of the tyre tread over one revolution, stationary radial displacement can be calculated and the true contact length can be estimated. This study provides us with new measurement data for comparison with mathematical modelling. It also gives a physical insight on generation mechanism of tyre radial vibrations.

Experimental Validation of Various Temperature Modells for Semi-Physical Tyre Model Approaches

Science.gov (United States)

Hackl, Andreas; Scherndl, Christoph; Hirschberg, Wolfgang; Lex, Cornelia

2017-10-01

With increasing level of complexity and automation in the area of automotive engineering, the simulation of safety relevant Advanced Driver Assistance Systems (ADAS) leads to increasing accuracy demands in the description of tyre contact forces. In recent years, with improvement in tyre simulation, the needs for coping with tyre temperatures and the resulting changes in tyre characteristics are rising significantly. Therefore, experimental validation of three different temperature model approaches is carried out, discussed and compared in the scope of this article. To investigate or rather evaluate the range of application of the presented approaches in combination with respect of further implementation in semi-physical tyre models, the main focus lies on the a physical parameterisation. Aside from good modelling accuracy, focus is held on computational time and complexity of the parameterisation process. To evaluate this process and discuss the results, measurements from a Hoosier racing tyre 6.0 / 18.0 10 LCO C2000 from an industrial flat test bench are used. Finally the simulation results are compared with the measurement data.

Measurement by a cylinder test stand and tyre rolling resistance

Directory of Open Access Journals (Sweden)

A. Dávid

2006-03-01

Full Text Available Sometimes it is necessary to test how repair affects the properties of the car. These tests are carried out using a cylinder test stand. During the test the tyre is rolling between two cylinders of a small diameter. The question arises whether the rolling resistance of the tyre is the same as the rolling resistance when the wheel is rolling on the plane. If it is not the same what is the reliation between tyre resistances in these two cases? It is an important answer because the change of rolling resistance can affect consumption, the highest speed, engine power and other results of measurement. The paper gives the answer to these questions and describes the method of getting this information.

Can electronic stability control replace studded tyres?

DEFF Research Database (Denmark)

Elvik, Rune

2015-01-01

Highlights • Electronic stability control can substitute studded tyres. • This makes it easier to discourage the use of studded tyres. • A certain level of use of studded tyres makes roads less slippery.......Highlights • Electronic stability control can substitute studded tyres. • This makes it easier to discourage the use of studded tyres. • A certain level of use of studded tyres makes roads less slippery....

Alexander the Great's tombolos at Tyre and Alexandria, eastern Mediterranean

Science.gov (United States)

Marriner, N.; Goiran, J. P.; Morhange, C.

2008-08-01

Tyre and Alexandria's coastlines are today characterised by wave-dominated tombolos, peculiar sand isthmuses that link former islands to the adjacent continent. Paradoxically, despite a long history of inquiry into spit and barrier formation, understanding of the dynamics and sedimentary history of tombolos over the Holocene timescale is poor. At Tyre and Alexandria we demonstrate that these rare coastal features are the heritage of a long history of natural morphodynamic forcing and human impacts. In 332 BC, following a protracted seven-month siege of the city, Alexander the Great's engineers cleverly exploited a shallow sublittoral sand bank to seize the island fortress; Tyre's causeway served as a prototype for Alexandria's Heptastadium built a few months later. We report stratigraphic and geomorphological data from the two sand spits, proposing a chronostratigraphic model of tombolo evolution.

All tyred out

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

With the mining equipment tyre shortage looking to be an issue until at least the end of the decade, the paper takes an in-depth look at the situation. Michelin, Bridgestone and Goodyear, the 'big three' suppliers are followed by Yokohama, Toyo, General, Belshina, Eurotire, Kumho and many Chinese brands. Michelin and Bridgestone have plans for expansion but many believe the shortage for large OEM tyres will continue to become more severe into 2008. The supply situation for smaller tyres should ease in early 2008 when Michelin's plant in Campo Grande, Brazil is completed. 3 photos.

Linear stochastic evaluation of tyre vibration due to tyre/road excitation

Science.gov (United States)

Rustighi, E.; Elliott, S. J.; Finnveden, S.; Gulyás, K.; Mócsai, T.; Danti, M.

2008-03-01

Tyre/road interaction is recognised as the main source of interior and exterior noise for velocities over the 40 km/h. In this paper, a three-dimensional (3D) elemental approach has been adopted to predict the stochastic tyre vibration and hence the interior and exterior noise due to this kind of excitation. The road excitation has been modelled from the spectral density of a common road profile, supposing the road to be an isotropic surface. A linear Winkler bedding connects the 3D model of the tyre with the ground. The exterior noise has been evaluated by an elemental calculation of the radiation matrix of the tyre deformed by the static load on a concrete road. The noise inside the vehicle has also been calculated, using the transfer functions from the force transmitted to the hub and the noise inside the vehicle, which have been computed by a FEM model of a common car body. The simple formulation allows much quicker calculation than traditional nonlinear approaches, and appears to give results consistent with available measurements, although the effects of tyre rotation and of the nonlinearities in the contact model are yet to be quantified, and the method requires further experimental validation before practical application.

Effect of crude oil contamination on the engineering behavior of clay soils

International Nuclear Information System (INIS)

Rehman, H.; Abdoljaowad, S.N.

2005-01-01

Humans are, unintentionally or intentionally contaminating soil from different sources. The contaminated soil are not only a challenge for the environmentalists but also for geotechnical engineers. When contaminated by crude oil, the soil is subjected to a change in its engineering properties. The soil, which is mostly affected by its environment, is clay, being active electro-chemically. So, a comprehensive laboratory-testing program was performed to compare the engineering properties of an uncontaminated and a contaminated clay. Laboratory tests included all basic and advanced geotechnical tests along with Scanning Electron Microscope (SEM). Crude oil was chosen as the contaminant. The clay was taken from the Al-Qatif area of the Eastern province of Saudi Arabia. The selected soil is considered to be highly expansive in nature. The comparison between uncontaminated and crude oil contaminated clay showed that there would be a significant change in the engineering behavior of the clay if it were contaminated by crude oil. The contaminated clay behaves more like sand, owing to the formation of agglomerates. The coarse-grained soil-like behavior was observed in the strength of the oil-contaminated clay. The contamination has affected the plasticity and the cation exchange capacity of the investigated clay. The swelling pressure of the contaminated clay is 1/3 of that of the uncontaminated clay while the swelling is almost the same. (author)

Pneumatic tyres interacting with deformable terrains

Science.gov (United States)

Bekakos, C. A.; Papazafeiropoulos, G.; O'Boy, D. J.; Prins, J.

2016-09-01

In this study, a numerical model of a deformable tyre interacting with a deformable road has been developed with the use of the finite element code ABAQUS (v. 6.13). Two tyre models with different widths, not necessarily identical to any real industry tyres, have been created purely for research use. The behaviour of these tyres under various vertical loads and different inflation pressures is studied, initially in contact with a rigid surface and then with a deformable terrain. After ensuring that the tyre model gives realistic results in terms of the interaction with a rigid surface, the rolling process of the tyre on a deformable road was studied. The effects of friction coefficient, inflation pressure, rebar orientation and vertical load on the overall performance are reported. Regarding the modelling procedure, a sequence of models were analysed, using the coupling implicit - explicit method. The numerical results reveal that not only there is significant dependence of the final tyre response on the various initial driving parameters, but also special conditions emerge, where the desired response of the tyre results from specific optimum combination of these parameters.

Clay slurry and engineered soils as containment technologies for remediation of contaminated sites

International Nuclear Information System (INIS)

Williams, J.R.; Dudka, S.; Miller, W.P.; Johnson, D.O.

1997-01-01

Clay Slurry and Engineered Soils are containment technologies for remediation of waste disposal sites where leaching, groundwater plumes and surface runoff of contaminants are serious ecological hazards to adjacent environments. This technology is a patent-pending process which involves the use of conditioned clay materials mixed with sand and water to form a readily pourable suspension, a clay slurry, which is either placed into a trench barrier system or allowed to de-water to create Engineered Soils. The Engineered Soil forms a layer impervious to water and air, therefore by inhibiting both water and oxygen from penetrating through the soil the material. This material can be installed in layers and as a vertical barrier to create a surface barrier containment system. The clay percentage in the clay slurry and Engineered Soils varies depending on site characteristics and desired performance standards. For example Engineered Soils with 1-2% of clay (dry wt.) had a hydraulic conductivity (K) of 10 -8 to 10 -1 cm/sec. Tests of tailing materials from a kyanite and pyrite mine showed that the clay slurry was effective not only in reducing the permeability of the treated tailings, but also in decreasing their acidity due to the inherent alkalinity of the clay. The untreated tailings had pH values in the range of 2.4 - 3.1; whereas, the effluent from clay and tailings mixtures had pH values in a slightly alkaline range (7.7-7.9). Pug-mills and high volume slurry pumps can be readily adapted for use in constructing and placing caps and creating Engineered Soils. Moreover, material on site or from a local sand supply can be used to create clay slurries and engineered soils. Clay materials used in cap construction are likewise readily available commercially. As a result, the clay slurry system is very cost effective compared to other capping systems, including the commonly used High Density Polyethylene (HDPE) liner systems

Truck tyre wear assessment and prediction

NARCIS (Netherlands)

Lupker, H.A.; Montanaro, F.; Donadio, D.; Gelosa, E.; Vis, M.A.

2002-01-01

Tyre wear is a complex phenomenon. It depends non-linearly on numerous parameters, like tyre compound and design, vehicle type and usage, road conditions and road surface characteristics, environmental conditions (e.g., temperature) and many others. Yet, tyre wear has many economic and ecological

Stabilization Of Marine Clay Using Biomass Silica-Rubber Chips Mixture

Science.gov (United States)

Marto, Aminaton; Ridzuan Jahidin, Mohammed; Aziz, Norazirah Abdul; Kasim, Fauziah; Zurairahetty Mohd. Yunus, Nor

2016-11-01

Marine clay is found widely along the coastal area and had caused expensive solutions in the construction of coastal highways. Hence, soil stabilization was suggested by some consultant to increase the strength of this soil in order to meet the highway construction requirement and also to achieve the specification for the development. Biomass Silica (BS), particularly the SH85 as a non-traditional stabilisation method, has been gaining more interest from the engineers recently. Rubber chips (RC), derived from waste rubber tyres, are considered ‘green’ element and had been used previously in some geotechnical engineering works. This paper presents the effect of using BS and RC as a mixture (BS-RC mixture), to increase the strength of marine clay for highway construction. Samples of marine clay, obtained from the West Coast Expressway project at Teluk Intan, Perak, were oven dried and grind to fine-grained sized. The marine clay was mixed with 9 % by weight proportion of BS- RC; that were 8%-l% and 7%-2%, respectively. For comparison purposes the result of BS-RC was compared to the result of stabilization by using 9% BS only. Laboratory tests were then carried out to determine the Atterberg limits and compaction characteristics of the untreated and treated marine clay. The Unconfined Compressive Strength (UCS) of the untreated and treated marine clays, compacted at the optimum moisture content was later obtained. The treated marine clay was tested at 0, 3 and 7 days curing periods. The results show that the Plasticity Index of BS-RC treated marine clay was lower than the untreated marine clay. From the UCS test results, it is shown that BS-RC mixtures had significantly improved the strength of marine clay. With the same percentage of 9% BS-RC, the increased of BS from 7% to 8% increased the UCS further to about six times more than untreated marine clay soils in 7 days curing period. The strength gained by using BS-RC at 8%-1% is slightly below the strength by

Evaluating the efficacy of wood shreds for mitigating erosion.

Science.gov (United States)

Foltz, Randy B; Copeland, Natalie S

2009-02-01

An erosion control product made by shredding on-site woody materials was evaluated for mitigating erosion through a series of rainfall simulations. Tests were conducted on bare soil and soil with 30, 50, and 70% cover on a coarse and a fine-grained soil. Results indicated that the wood product known as wood shreds reduced runoff and soil loss from both soil types. Erosion mitigation ranged from 60 to nearly 100% depending on the soil type and amount of concentrated flow and wood shred cover. Wood shreds appear to be a viable alternative to agricultural straw. A wood shred cover of 50% appears optimal, but the appropriate coverage rate will depend on the amount of expected concentrated flow and soil type.

Clays in natural and engineered barriers for radioactive waste confinement

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

Andra organised an International Symposium on the use of Natural and Engineered Clay-based Barriers for the Containment of Radioactive Waste hold at the Congress Centre of Tours, France, in March 2005. The symposium provided an opportunity to take stock of the potential properties of the clay-based materials present in engineered or natural barriers in order to meet the containment specifications of a deep geological repository for radioactive waste. It was intended for specialists working in the various disciplines involved with clays and clay based minerals, as well as scientists from agencies and organisations dealing with investigations on the disposal of high-level and long-lived radioactive waste. The themes of the Symposium included geology, geochemistry, transfers of materials, alteration processes, geomechanics, as well as the recent developments regarding the characterisation of clays, as well as experiments in surface and underground laboratories. The symposium consisted of plenary sessions, parallel specialized sessions and poster sessions. (author)

485 assessment of the problems of manual automobile tyre bead

African Journals Online (AJOL)

eobe

rim bead bond must be broken to carry out repairs on a failed automobile tyre. ... engine will not be transformed into the motion of the vehicle. It provides the only point of contact between ..... Popular Mechanic 162 (6): 62. http://books.google.

Modelling effects of tyre inflation pressure on the stress distribution near the soil-tyre interface

DEFF Research Database (Denmark)

Schjønning, Per; Lamandé, Mathieu; Tøgersen, Frede A

2008-01-01

stress in the contact area for two radial-ply agricultural trailer tyres (650/65R30.5 and 800/50R34) loaded with 60 kN. The study took place on a sandy soil at a water content slightly less than field capacity. We tested the effect of three different inflation pressures (50, 100 and 240 k......Pa) in a randomised block design with three replicates. The vertical stress was measured with load cells located in 0.1 m soil depth. The vertical stress data were used also for identifying the soil area in contact with the tyre, i.e. the tyre footprint. A model (named FRIDA) is proposed that describes the tyre...... footprint by a super ellipse and the stress distribution by a combined exponential (perpendicular to the driving direction) and power-law (along the driving direction) function. The contact area doubled when the inflation pressure was reduced from 240 to 50 kPa. For both tyres, the measured peak stress...

Pavement Response to Variable Tyre Pressure of Heavy Vehicles

Directory of Open Access Journals (Sweden)

Arshad Ahmad Kamil

2016-01-01

Full Text Available In recent years, the effect of overinflated tyre pressure and increased heavy vehicles’ axle load on flexible pavements has become a subject of great concern because of the higher stress levels induced and damage caused to road pavements. This paper aims to evaluate the effect of variable tyre inflation pressures (using actual tyre contact/footprint area to determine the responses of flexible pavement. A full scale experiment was conducted on a heavy vehicle with 1:1:2 axle configuration, 10 R 20 tyre size and attached trailer with constant axle load. Measurements were made for actual tyre-pavement contact area. KENPAVE linear elastic program was then used to analyse the effects of the measured actual tyre-pavement contact area and the results was compared using conventional circular tyre contact area. A comparative analysis was then made between the actual contact area and the conventional circular tyre contact area. It was found that high tyre inflation pressure produce smaller contact area, giving more detrimental effect on the flexible pavement. It was also found that the temperature of tyres when the heavy vehicles are operational give less significant impact on tyre inflation pressure for the Malaysian climate.

Magic Formula Tyre Model with Transient Properties

NARCIS (Netherlands)

Pacejka, H.B.; Besselink, I.J.M.

1997-01-01

The tyre force and moment generating properties connected with the vehicle's horizontal motions are considered. Knowledge of tyre properties is necessary to properly design vehicle components and advanced control systems. For this purpose, mathematical models of the tyre are being used in vehicle

development of a motorized parboiled cassava tuber shredding

African Journals Online (AJOL)

2013-03-01

Mar 1, 2013 ... erance to extreme ecological stress and sustainability to present farming and ... Higher capacity compared to traditional method of shredding cassava. 2. .... weight of uncompleted shredded tuber, at different steaming time at a ...

Tyre Recycling with Thermal Solvolysis Method Using Microwave Radiation

OpenAIRE

Korjakins, Aleksandrs; Holimenkovs, Aleksandrs

2017-01-01

Used tyres are one of the most widespread types of waste and one of the polymer materials which are most difficult to recycle. There are many different applications for used tyres today. Part of the tyres can be retreated and re-used, but most of the used tyres are recycled. By dissolving the tyres, it is possible to filter out various chemical substances. These substances coming from the used tyres can be used for creating a new material or improving an existing one. One of the technologies ...

Properties of Shredded Roof Membrane–Sand Mixture and Its Application as Retaining Wall Backfill under Static and Earthquake Loads

Directory of Open Access Journals (Sweden)

Bennett Livingston

2017-04-01

Full Text Available About 20 billion square feet of Ethylene Propylene Diene Monomer (EPDM rubber is installed on roofs in the United States and most of them will be reaching the end of their lifespan soon. The purpose of this study is to investigate potential reuses of this rubber in Civil Engineering projects rather than disposing it into landfills. First, laboratory tests were performed on various shredded rubber-sand mixtures to quantify the basic geotechnical engineering properties. The laboratory test results show that the shredded rubber-sand mixture is lightweight with good drainage properties and has shear strength parameters comparable to sand. This indicates that the rubber-sand mixture has potential to be used for retaining wall backfill and many other projects. To assess the economic advantage of using shredded rubber-sand mixtures as a lightweight backfill for retaining walls subjected to static and earthquake loadings, geotechnical designs of a 6 m tall gravity cantilever retaining wall were performed. The computed volume of concrete to build the structural components and volume of backfill material were compared with those of conventional sand backfill. Results show significant reductions in the volume of concrete and backfill material in both static and earthquake loading conditions when the portion of shredded rubber increased in the mixture.

Initial research on recycled tyre bales for road infrastructure applications

Science.gov (United States)

Duda, Aleksander; Sobala, Dariusz

2017-12-01

The paper reviews selected surveys carried out within the R&D project, co-financed with the European Regional Development Fund, called "ReUse - Innovative Recycling Materials, Enhancing the Sustainability of Bridge Facilities" (Innotech No. K3 / IN3 / 38/228116 / NCBiR / 15). The aim of the project and conducted research is to develop and implement innovative, cheap and environmentally-friendly recycled construction material in the form of tyre bales made from compressed used car tyres. This material is likely to be applied in civil engineering, especially in transport infrastructure, geotechnical and hydraulic engineering. New material is cheap and has unique properties such as low weight, high water permeability, high vibration and noise-damping capacity, low pressure coefficient values and other parameters that technically and economically allow it to replace natural aggregates. The extensive practical application of new material will facilitate the replacement of waste management methods with the environmentally friendly ones.

Test benches for studying the properties of car tyres

Science.gov (United States)

Kuznetsov, N. Yu.; Fedotov, A. I.; Vlasov, V. G.

2017-12-01

The article describes the design of the measuring systems of test benches used to study the properties of elastic tyres. The bench has two autonomous systems - for testing the braking properties of elastic tyres rolling in a plane parallel way and for testing tyre slip properties. The system for testing braking properties determines experimental characteristics of elastic tyres as the following dependencies: longitudinal response vs time, braking torque vs slip, angular velocity vs slip, and longitudinal response vs slip. The system for studying tyre slip properties determines both steady (dependence of the lateral response in a contact area on the slipping angle) and non-steady characteristics (time variation of the slipping angle as a result of turning from -40 to +40 degrees) of tyre slip. The article presents the diagrams of bench tests of elastic tyres. The experimental results show metrological parameters and functional capabilities of the bench for studying tyre properties in driving and braking modes. The metrological indices of the recorded parameters of the measuring system for studying tyre properties are presented in the table.

Tyre and road wear prediction

NARCIS (Netherlands)

Lupker, H.A.

2003-01-01

Both tyre wear and road polishing are complex phenomenon, which are obviously strongly related; the energy that polishes the road is the energy that wears the tyre. The both depend non-linearly on numerous parameters, like materials used, vehicle and road usage, environmental conditions (i.e.

Pavement damaging effects from dual tyre configurations of heavy vehicles with tyre inflation pressure differentials

CSIR Research Space (South Africa)

De Beer, M

2015-08-16

Full Text Available inflation pressure data in addition to tyre loading resulted in a rough empirical estimate of tyre inflation pressure directly from SIM contact stress measurements. In an ideal world, an instrument such as the SIM could be invaluable in not only capturing...

Pavement damaging effects from dual tyre configurations of heavy vehicles with tyre inflation pressure differentials

CSIR Research Space (South Africa)

De Beer, M

2015-08-01

Full Text Available inflation pressure data in addition to tyre loading resulted in a rough empirical estimate of tyre inflation pressure directly from SIM contact stress measurements. In an ideal world, an instrument such as the SIM could be invaluable in not only capturing...

Tire Shred Backfill in Mechanically Stabilized Earth Wall Applications

OpenAIRE

Balunaini, Umashankar; Yoon, Sungmin; Prezzi, Monica; Salgado, Rodrigo

2009-01-01

Tire shred-soil mixture backfill for use in mechanically stabilized earth (MSE) walls has several advantages over traditional backfill materials: 1) good drainage, 2) high shear strength, 3) low compacted unit weight and 4) low lateral pressure exerted on retaining structures. This work presents the results of laboratory tests performed on tire shred-sand mixtures focusing on determining the properties required for their use as backfill in MSE wall applications. Three sizes of tire shreds are...

Vegetative Regeneration Capacities of Five Ornamental Plant Invaders After Shredding

Science.gov (United States)

Monty, Arnaud; Eugène, Marie; Mahy, Grégory

2015-02-01

Vegetation management often involves shredding to dispose of cut plant material or to destroy the vegetation itself. In the case of invasive plants, this can represent an environmental risk if the shredded material exhibits vegetative regeneration capacities. We tested the effect of shredding on aboveground and below-ground vegetative material of five ornamental widespread invaders in Western Europe that are likely to be managed by cutting and shredding techniques: Buddleja davidii (butterfly bush, Scrophulariaceae), Fallopia japonica (Japanese knotweed, Polygonaceae), Spiraea × billardii Hérincq (Billard's bridewort, Rosaceae), Solidago gigantea (giant goldenrod, Asteraceae), and Rhus typhina L. (staghorn sumac, Anacardiaceae). We looked at signs of vegetative regeneration and biomass production, and analyzed the data with respect to the season of plant cutting (spring vs summer), the type of plant material (aboveground vs below-ground), and the shredding treatment (shredded vs control). All species were capable of vegetative regeneration, especially the below-ground material. We found differences among species, but the regeneration potential was generally still present after shredding despite a reduction of growth rates. Although it should not be excluded in all cases (e.g., destruction of giant goldenrod and staghorn sumac aboveground material), the use of a shredder to destroy woody alien plant material cannot be considered as a general management option without significant environmental risk.

Predicting the compressibility behaviour of tire shred samples for landfill applications.

Science.gov (United States)

Warith, M A; Rao, Sudhakar M

2006-01-01

Tire shreds have been used as an alternative to crushed stones (gravel) as drainage media in landfill leachate collection systems. The highly compressible nature of tire shreds (25-47% axial strain on vertical stress applications of 20-700 kPa) may reduce the thickness of the tire shred drainage layer to less than 300 mm (minimum design requirement) during the life of the municipal solid waste landfill. There hence exists a need to predict axial strains of tire shred samples in response to vertical stress applications so that the initial thickness of the tire shred drainage layer can be corrected for compression. The present study performs one-dimensional compressibility tests on four tire shred samples and compares the results with stress/strain curves from other studies. The stress/strain curves are developed into charts for choosing the correct initial thickness of tire shred layers that maintain the minimum thickness of 300 mm throughout the life of the landfill. The charts are developed for a range of vertical stresses based on the design height of municipal waste cell and bulk unit weight of municipal waste. Experimental results also showed that despite experiencing large axial strains, the average permeability of the tire shred sample consistently remained two to three orders of magnitude higher than the design performance criterion of 0.01cm/s for landfill drainage layers. Laboratory experiments, however, need to verify whether long-term chemical and bio-chemical reactions between landfill leachate and the tire shred layer will deteriorate their mechanical functions (hydraulic conductivity, compressibility, strength) beyond permissible limits for geotechnical applications.

Survey on Road-Tyre Contact Patch Pattern and Wear Related Aspects

OpenAIRE

Azodo Adinife Patrick

2017-01-01

Motor vehicle end-users approaches to tyre safety issues in automobiles translate to a number of tyre failure risk factors. This study basically assessed tread wear pattern of tyres in passenger cars used on Nigeria roads. The result obtained showed that 75.4% of the assessed tyres showed uneven wear pattern resulting from incorrect tyre-road contact effects. This observed high proportion of uneven tyre tread wear pattern implies high rate of inconsequential regard for tyre safety.

Survey on Road-Tyre Contact Patch Pattern and Wear Related Aspects

Directory of Open Access Journals (Sweden)

Azodo Adinife Patrick

2017-11-01

Full Text Available Motor vehicle end-users approaches to tyre safety issues in automobiles translate to a number of tyre failure risk factors. This study basically assessed tread wear pattern of tyres in passenger cars used on Nigeria roads. The result obtained showed that 75.4% of the assessed tyres showed uneven wear pattern resulting from incorrect tyre-road contact effects. This observed high proportion of uneven tyre tread wear pattern implies high rate of inconsequential regard for tyre safety.

Immobilisation of shredded waste in a cement monolith

International Nuclear Information System (INIS)

James, J.M.; Smith, D.L.

1987-11-01

During 1983/84 work was continued on the development of the process for the encapsulation of shredded waste in cement. Using simulant shredded waste the conditions for operating the process on the 500 litres scale have been established. Evaluation of the cemented product showed that it was satisfactorily infilled with cement grout with no significant voidage. (author)

Valorization of used tyres as fuel substitute in cement industry; Valorisation des pneus usages comme combustible de substitution en cimenterie

Energy Technology Data Exchange (ETDEWEB)

Anon.

1999-03-01

According to the French syndicate of cement industry, more than 350000 t of worn tyres are produced each year in France, among which only 143000 t are reused in retreading, exported as used tyres or valorized in cement industry. The rest is generally tipped or burnt in the open-air. In cement kilns, the organic matters of tyres are completely burnt while the metal belts supply the necessary amount of iron to the cement composition. The combustion of tyres produces no black smoke, no smell and no ash and has no significant influence on the effluents of cement factories: gases are directly filtered in the kiln by the important mass of raw materials which acts as quicklime. In 1997, 31500 t of used tyres were burnt in the seven French cement factories over 34 that use this kind of fuel and represents 1.5% of the total energy needs. This substitution ratio could easily reach 10 to 15% without leading to any additional environmental or technical problem. A project of collection and valorization of used tyres has been developed by the French ministry of environment and aims at completely eliminating tyres tipping since July 1, 2002. In order to illustrate the French policy of tyres valorization, two examples of actions are presented in this paper: the first one is carried out by the Michelin manufacturer in order to facilitate the recycling of civil engineering tyres, and the second is carried out by Ciments d`Origny company at the Rochefort factory where tyres are used as fuel substitutes. (J.S.)

Choice of french clays as engineered barrier components for waste disposal

International Nuclear Information System (INIS)

Coulon, H.; Lajudie, A.; Debrabant, P.; Atabek, R.; Jorda, M.; Andre-Jehan, R.

1987-01-01

Results are presented of physical measurements on candidate buffer materials for use in nuclear fuel waste disposal. The materials being considered as constituent elements of engineered barriers are essentially calcium smectite clays, in other terms swelling clays, coming from fourteen french deposits. The criteria for good candidates are mainly: smectite content in the clay materials, carbonate and organic material content and bulk density of the material, compacted under a pressure of 100 MPa. 14 references, 4 figures, 6 tables

Tyre tread-block friction: modelling, simulation and experimental validation

Science.gov (United States)

Wallaschek, Jörg; Wies, Burkard

2013-07-01

Pneumatic tyres are used in vehicles since the beginning of the last century. They generate braking and steering forces for bicycles, motor cycles, cars, busses, trucks, agricultural vehicles and aircraft. These forces are generated in the usually very small contact area between tyre and road and their performance characteristics are of eminent importance for safety and comfort. Much research has been addressed to optimise tyre design with respect to footprint pressure and friction. In this context, the development of virtual tyre prototypes, that is, simulation models for the tyre, has grown to a science in its own. While the modelling of the structural dynamics of the tyre has reached a very advanced level, which allows to take into account effects like the rate-independent inelasticity of filled elastomers or the transient 3D deformations of the ply-reinforced tread, shoulder and sidewalls, little is known about the friction between tread-block elements and road. This is particularly obvious in the case when snow, ice, water or a third-body layer are present in the tyre-road contact. In the present paper, we give a survey on the present state of knowledge in the modelling, simulation and experimental validation of tyre tread-block friction processes. We concentrate on experimental techniques.

Phenomenological analysis of hydroplaning through intelligent tyres

Science.gov (United States)

D'Alessandro, Vincenzo; Melzi, Stefano; Sbrosi, Marco; Brusarosco, Massimo

2012-01-01

Hydroplaning, as well known, greatly affects safety since it leads to the loss of contact between the tyre and the road, preventing the vehicle from responding to control inputs such as steering, braking and acceleration. Sensorised tyres developed in recent years have proved to be able to detect hydroplaning risks in terms of proximity to the so-called hydroplaning speed. The availability of such devices can push towards the development of control systems that are able to preserve vehicle stability and directionality also close to hydroplaning onset. This paper presents results relevant to the identification of hydroplaning proximity through smart tyres and describes an experimental campaign focused on the identification of the lateral response of tyres while approaching the hydroplaning speed.

Radioactive waste shredding: Preliminary evaluation

International Nuclear Information System (INIS)

Soelberg, N.R.; Reimann, G.A.

1994-07-01

The critical constraints for sizing solid radioactive and mixed wastes for subsequent thermal treatment were identified via a literature review and a survey of shredding equipment vendors. The types and amounts of DOE radioactive wastes that will require treatment to reduce the waste volume, destroy hazardous organics, or immobilize radionuclides and/or hazardous metals were considered. The preliminary steps of waste receipt, inspection, and separation were included because many potential waste treatment technologies have limits on feedstream chemical content, physical composition, and particle size. Most treatment processes and shredding operations require at least some degree of feed material characterization. Preliminary cost estimates show that pretreatment costs per unit of waste can be high and can vary significantly, depending on the processing rate and desired output particle size

Noise source localization on tyres using an inverse boundary element method

DEFF Research Database (Denmark)

Schuhmacher, Andreas; Saemann, E-U; Hald, J

1998-01-01

A dominating part of tyre noise is radiated from a region close to the tyre/road contact patch, where it is very difficult to measure both the tyre vibration and the acoustic near field. The approach taken in the present paper is to model the tyre and road surfaces with a Boundary Element Model...... (BEM), with unknown node vibration data on the tyre surface. The BEM model is used to calculate a set of transfer functions from the node vibrations to the sound pressure at a set of microphone positions around the tyre. By approximate inversion of the matrix of transfer functions, the surface...... from tyre noise measurements will be presented at the conference....

A comparison of linear tyre models for analysing shimmy

NARCIS (Netherlands)

Besselink, I.J.M.; Maas, J.W.L.H.; Nijmeijer, H.

2011-01-01

A comparison is made between three linear, dynamic tyre models using low speed step responses and yaw oscillation tests. The match with the measurements improves with increasing complexity of the tyre model. Application of the different tyre models to a two degree of freedom trailing arm suspension

Bioleaching of metals from WEEE shredding dust.

Science.gov (United States)

Marra, Alessandra; Cesaro, Alessandra; Rene, Eldon R; Belgiorno, Vincenzo; Lens, Piet N L

2018-03-15

A bioleaching process developed in two separate steps was investigated for the recovery of base metals, precious metals and rare earth elements from dusts generated by Waste Electrical and Electronic Equipment (WEEE) shredding. In the first step, base metals were almost completely leached from the dust in 8 days by Acidithiobacillus thiooxidans (DSM 9463) that lowered the pH of the leaching solution from 3.5 to 1.0. During this step, cerium, europium and neodymium were mobilized at high percentages (>99%), whereas lanthanum and yttrium reached an extraction yield of 80%. In the second step, the cyanide producing Pseudomonas putida WSC361 mobilized 48% of gold within 3 h from the A. thiooxidans leached shredding dust. This work demonstrated the potential application of biohydrometallurgy for resource recovery from WEEE shredding dust, destined to landfill disposal, and its effectiveness in the extraction of valuable substances, including elements at high supply risk as rare earths. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modelling vertical uniform contact stress of heavy vehicle tyres

CSIR Research Space (South Africa)

Steenkamp, Anton J

2016-07-01

Full Text Available over the selected operating range of 25 kN to 45 kN which is the typical load range for heavy vehicle tyres due to legal axle load limits. The polynomial formulas require only the tyre inflation pressure and vertical tyre load as inputs, in order...

Contact stiffness considerations when simulating tyre/road noise

Science.gov (United States)

Winroth, Julia; Kropp, Wolfgang; Hoever, Carsten; Höstmad, Patrik

2017-11-01

Tyre/road simulation tools that can capture tyre vibrations, rolling resistance and noise generation are useful for understanding the complex processes that are involved and thereby promoting further development and optimisation. The most detailed tyre/road contact models use a spatial discretisation of the contact and assume an interfacial stiffness to account for the small-scale roughness within the elements. This interfacial stiffness has been found to have a significant impact on the simulated noise emissions but no thorough investigations of this sensitivity have been conducted. Three mechanisms are thought to be involved: The horn effect, the modal composition of the vibrational field of the tyre and the contact forces exciting the tyre vibrations. This study used a numerical tyre/road noise simulation tool based on physical relations to investigate these aspects. The model includes a detailed time-domain contact model with linear or non-linear contact springs that accounts for the effect of local tread deformation on smaller length scales. Results confirm that an increase in contact spring stiffness causes a significant increase of the simulated tyre/road noise. This is primarily caused by a corresponding increase in the contact forces, resulting in larger vibrational amplitudes. The horn effect and the modal composition are relatively unaffected and have minor effects on the radiated noise. A more detailed non-linear contact spring formulation with lower stiffness at small indentations results in a reduced high-frequency content in the contact forces and the simulated noise.

THE ADDED VALUE OF SHREDDED LELE AND PATIN CATFISH

Directory of Open Access Journals (Sweden)

Ristina Siti Sundari

2017-09-01

Full Text Available Fish is not only perishable product but also has segmented market. Consumption market such wants the fresh fish and certainty size. The problem is when the size of fish is too big for consumption, so that product is not wanted by consumer anymore. This research aimed at knowing the added value of shredded Lele and Patin catfish agribusiness and increasing prosperity of humanitarian society throughout processing the shredded catfishes. The data of this research was analyzed by Added Value Analysis of Hayami. The result showed that the shredded product of Lele catfish gave the added value IDR 14.295,00 per kilograms with the added value ratio was 25,53 percent and Conversion value was 0,35. Whereas, the shredded product of Patin catfish gave the added value IDR 18.295,00 per kilogram with the added value ratio was 29,04 percent and Conversion value was 0,35. The agribusiness toward processing and marketing of shredded Lele and Patin catfish was innovative agribusiness that could develop business opportunity so that it could move on the economical wheel and increasing humanitarian society prosperity actively. The market demand was still very wide either in town or out of town. The partnership among various not only government but also non government associations would be a good matter toward this agribusiness is running well.

Towards Understanding Tyre-Pavement Contact in APT Research on Flexible Pavements

CSIR Research Space (South Africa)

De Beer, Morris

2016-09-01

Full Text Available An important element of Accelerated Pavement Testing (APT) is the selection of appropriate test tyre(s) to be used for APT testing. By far the majority of full scale (or scaled) APT devices uses pneumatic rubber tyres. Tyres differ not only in size...

Tyre-pavement contact stress patterns from the test tyres of the Gautrans heavy vehicle simulator (HVS) MK IV+

CSIR Research Space (South Africa)

De Beer, Morris

2005-07-01

Full Text Available premises. A test matrix of five load levels and six inflation pressures was used on both HVS test tyres at creep speed conditions (<6km/hr). The results indicated that at constant inflation pressure the vertical tyre contactpattern (“fingerprint”) is highly...

Construction of a test embankment using a sand-tire shred mixture as fill material.

Science.gov (United States)

Yoon, Sungmin; Prezzi, Monica; Siddiki, Nayyar Zia; Kim, Bumjoo

2006-01-01

Use of tire shreds in construction projects, such as highway embankments, is becoming an accepted way of beneficially recycling scrap tires. However, in the last decade there was a decline in the use of pure tire shreds as fill materials in embankment construction, as they are susceptible to fire hazards due to the development of exothermic reactions. Tire shred-sand mixtures, on the other hand, were found to be effective in inhibiting exothermic reactions. When compared with pure tire shreds, tire shred-sand mixtures are less compressible and have higher shear strength. However, the literature contains limited information on the use of tire shred-soil mixtures as a fill material. The objectives of this paper are to discuss and evaluate the feasibility of using tire shred-sand mixtures as a fill material in embankment construction. A test embankment constructed using a 50/50 mixture, by volume, of tire shreds and sand was instrumented and monitored to: (a) determine total and differential settlements; (b) evaluate the environmental impact of the embankment construction on the groundwater quality due to leaching of fill material; and (c) study the temperature variation inside the embankment. The findings in this research indicate that mixtures of tire shreds and sand are viable materials for embankment construction.

A theoretical model of speed-dependent steering torque for rolling tyres

Science.gov (United States)

Wei, Yintao; Oertel, Christian; Liu, Yahui; Li, Xuebing

2016-04-01

It is well known that the tyre steering torque is highly dependent on the tyre rolling speed. In limited cases, i.e. parking manoeuvre, the steering torque approaches the maximum. With the increasing tyre speed, the steering torque decreased rapidly. Accurate modelling of the speed-dependent behaviour for the tyre steering torque is a key factor to calibrate the electric power steering (EPS) system and tune the handling performance of vehicles. However, no satisfactory theoretical model can be found in the existing literature to explain this phenomenon. This paper proposes a new theoretical framework to model this important tyre behaviour, which includes three key factors: (1) tyre three-dimensional transient rolling kinematics with turn-slip; (2) dynamical force and moment generation; and (3) the mixed Lagrange-Euler method for contact deformation solving. A nonlinear finite-element code has been developed to implement the proposed approach. It can be found that the main mechanism for the speed-dependent steering torque is due to turn-slip-related kinematics. This paper provides a theory to explain the complex mechanism of the tyre steering torque generation, which helps to understand the speed-dependent tyre steering torque, tyre road feeling and EPS calibration.

Observers for vehicle tyre/road forces estimation: experimental validation

Science.gov (United States)

Doumiati, M.; Victorino, A.; Lechner, D.; Baffet, G.; Charara, A.

2010-11-01

The motion of a vehicle is governed by the forces generated between the tyres and the road. Knowledge of these vehicle dynamic variables is important for vehicle control systems that aim to enhance vehicle stability and passenger safety. This study introduces a new estimation process for tyre/road forces. It presents many benefits over the existing state-of-art works, within the dynamic estimation framework. One of these major contributions consists of discussing in detail the vertical and lateral tyre forces at each tyre. The proposed method is based on the dynamic response of a vehicle instrumented with potentially integrated sensors. The estimation process is separated into two principal blocks. The role of the first block is to estimate vertical tyre forces, whereas in the second block two observers are proposed and compared for the estimation of lateral tyre/road forces. The different observers are based on a prediction/estimation Kalman filter. The performance of this concept is tested and compared with real experimental data using a laboratory car. Experimental results show that the proposed approach is a promising technique to provide accurate estimation. Thus, it can be considered as a practical low-cost solution for calculating vertical and lateral tyre/road forces.

Recycling supercapacitors based on shredding and mild thermal treatment.

Science.gov (United States)

Jiang, Guozhan; Pickering, Stephen J

2016-02-01

Supercapacitors are widely used in electric and hybrid vehicles, wind farm and low-power equipment due to their high specific power density and huge number of charge-discharge cycles. Waste supercapacitors should be recycled according to EU directive 2002/96/EC on waste electric and electronic equipment. This paper describes a recycling approach for end-of-life supercapacitors based on shredding and mild thermal treatment. At first, supercapacitors are shredded using a Retsch cutting mill. The shredded mixture is then undergone thermal treatment at 200°C to recycle the organic solvent contained in the activated carbon electrodes. After the thermal treatment, the mixture is roughly separated using a fluidized bed method to remove the aluminium foil particles and paper particles from the activated carbon particles, which is subsequently put into water for a wet shredding into fine particles that can be re-used. The recycled activated carbon has a BET surface area of up to 1200m(2)/g and the recycled acetonitrile has a high purity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Clay-based materials for engineered barriers: a review

International Nuclear Information System (INIS)

Lajudie, A.; Raynal, J.; Petit, J.C.; Toulhoat, P.

1994-01-01

The potential importance of backfilling and plugging in underground radioactive waste repositories has led different research institutions to carry out extensive studies of swelling clay materials for the development of engineered barriers in underground conditions. These materials should combine a variety of hydro-thermo-mechanical and geochemical properties: impermeability, swelling ability in order to fill all void space, heat transfer and retention capacity for the most noxious radionuclides. Smectite clays best exhibit these properties and most of the research effort has been devoted to this type of materials. In this paper, mineralogical composition, sodium or calcium content, thermo-hydro-mechanical properties, swelling pressure, hydraulic and thermal conductivity, and chemical properties of five smectite clays selected by five major nuclear countries are reviewed: Avonseal montmorillonite (Canada), MX 80 montmorillonite (Sweden), Montigel montmorillonite (Switzerland), S-2 montmorillonite (Spain), and Fo-Ca inter stratified kaolinite/beidellite (France). (J.S.). 29 refs., 5 figs., 3 tabs

The immobilisation of shredded waste in a cement matrix

International Nuclear Information System (INIS)

James, J.M.; Smith, D.L.

1985-10-01

Progress on the preparations for the encapsulation of plutonium contaminated shredded waste is summarised. Waste drums have been modified and filled with active shredded waste. Commissioning of the grout infilling test rig was started at the end of this period. Inactive process trials have continued in support of the design of the active encapsulation plant. (author)

Assessment of the Problems of Manual Automobile Tyre Bead ...

African Journals Online (AJOL)

The tyre-rim bead bond must be broken to carry out repairs on a failed automobile tyre. The use of the locally fabricated manual bead breaking equipment as it is being practiced today by commercial tyre repair artisans in Nigeria is characterized by drudgery. This article reports a study of the local manual bead breaking ...

Clays in natural and engineered barriers for radioactive waste confinement

International Nuclear Information System (INIS)

2007-01-01

The meeting covers all topics concerning natural argillaceous geological barriers and the clay material based engineered barrier systems, investigated by means of: laboratory experiments on clay samples (new analytical developments), in situ experiments in underground research laboratories, mock-up demonstrations, natural analogues, as well as numerical modelling and global integration approaches (including up-scaling processes and treatment of uncertainties). The works presented deal with: examples of broad research programs (national or international) on the role of natural and artificial clay barriers for radionuclide confinement; clay-based repository concepts: repository designs, including technological and safety issues related to the use of clay for nuclear waste confinement; geology and clay characterisation: mineralogy, sedimentology, paleo-environment, diagenesis, dating techniques, discontinuities in rock clay, fracturing, self sealing processes, role of organic matter and microbiological processes; geochemistry: pore water geochemistry, clay thermodynamics, chemical retention, geochemical modelling, advanced isotopic geochemistry; mass transfer: water status and hydraulic properties in low permeability media, pore space geometry, water, solute and gas transfer processes, colloid mediated transport, large scale movements, long-term diffusion; alteration processes: oxidation effects, hydration-dehydration processes, response to thermal stress, iron-clay interactions, alkaline perturbation; geomechanics: thermo-hydro-mechanical behaviour of clay, rheological models, EDZ characterisation and evolution, coupled behaviour and models (HM, THM, THMC). A particular interest is given to potential contributions coming from fields of activities other than radioactive waste management, which take advantage of the confinement properties of the clay barrier (oil and gas industries, gas geological storage, CO 2 geological sequestration, chemical waste isolation

Clays in natural and engineered barriers for radioactive waste confinement

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

The meeting covers all topics concerning natural argillaceous geological barriers and the clay material based engineered barrier systems, investigated by means of: laboratory experiments on clay samples (new analytical developments), in situ experiments in underground research laboratories, mock-up demonstrations, natural analogues, as well as numerical modelling and global integration approaches (including up-scaling processes and treatment of uncertainties). The works presented deal with: examples of broad research programs (national or international) on the role of natural and artificial clay barriers for radionuclide confinement; clay-based repository concepts: repository designs, including technological and safety issues related to the use of clay for nuclear waste confinement; geology and clay characterisation: mineralogy, sedimentology, paleo-environment, diagenesis, dating techniques, discontinuities in rock clay, fracturing, self sealing processes, role of organic matter and microbiological processes; geochemistry: pore water geochemistry, clay thermodynamics, chemical retention, geochemical modelling, advanced isotopic geochemistry; mass transfer: water status and hydraulic properties in low permeability media, pore space geometry, water, solute and gas transfer processes, colloid mediated transport, large scale movements, long-term diffusion; alteration processes: oxidation effects, hydration-dehydration processes, response to thermal stress, iron-clay interactions, alkaline perturbation; geomechanics: thermo-hydro-mechanical behaviour of clay, rheological models, EDZ characterisation and evolution, coupled behaviour and models (HM, THM, THMC). A particular interest is given to potential contributions coming from fields of activities other than radioactive waste management, which take advantage of the confinement properties of the clay barrier (oil and gas industries, gas geological storage, CO{sub 2} geological sequestration, chemical waste isolation

Evaluation of pressed shredded empty fruit bunch (EFB)-palm oil ...

African Journals Online (AJOL)

Pressed-shredded empty fruit bunches (EFB) and palm oil mill effluent (POME) anaerobic sludge from a 500 m3 closed anaerobic digester system was utilized for the co-composting treatment. Scanning electron microscopy (SEM) analysis showed that the shredding-pressing treatment on EFB gave better results in ...

Radiation pre-vulcanization effect on properties of the truck tyre's transition layer and the truck tyre

International Nuclear Information System (INIS)

Yang Mingcheng; Zhu Jun; Li Kunhao; Guo Dongquan; Zhang Hongna; Zhang Benshang; Li Zhaopeng

2013-01-01

In this paper, the natural rubber is chosen as the main constituents for the transition layer of all-steel load radial tyre, which is pre-vulcanized by 500-keV E-beam irradiation of up to 60 kGy. The results show that the green strength of transitional layer increases with the dose, reaching four times as much as the control (without irradiation) at 60 kGy. The final mechanical properties do not differ significantly from those of the control except that the aging and fatigue performance increased. However, thickness of the natural rubber transitional layer for an average single tyre can be reduced by 1 mm (or 1.5 kg) without obvious adverse effect on tyre performance. (authors)

Identification of the mechanical properties of bicycle tyres for modelling of bicycle dynamics

Science.gov (United States)

Doria, Alberto; Tognazzo, Mauro; Cusimano, Gianmaria; Bulsink, Vera; Cooke, Adrian; Koopman, Bart

2013-03-01

Advanced simulation of the stability and handling properties of bicycles requires detailed road-tyre contact models. In order to develop these models, in this study, four bicycle tyres are tested by means of a rotating disc machine with the aim of measuring the components of tyre forces and torques that influence the safety and handling of bicycles. The effect of inflation pressure and tyre load is analysed. The measured properties of bicycle tyres are compared with those of motorcycle tyres.

Tyres and road surfaces : experimental multifactor investigation of the factors affecting the brake and side way forces between car tyres and wet road surfaces : summary, conclusions and recommendations from the study by Sub-Committee I of the Working Group on "Tyres, Road Surfaces and Skidding Accidents".

NARCIS (Netherlands)

1976-01-01

The study concerning the contact between a tyre and the road surface was conducted in three phases. In the first phase the first and second-order factors were separated. The factors: type of road surface, tyre type, tread depth, water depth, tyre pressure and tyre load were included in an

Detection of the local sliding in the tyre-road contact by measuring vibrations on the inner liner of the tyre

Science.gov (United States)

Niskanen, Arto J.; Tuononen, Ari J.

2017-04-01

Intelligent tyres can provide vital information from the tyre-road contact, especially for autonomous cars and intelligent infrastructure. In this paper, the acceleration measured on the inner liner of a tyre is used to detect the local sliding in the tyre-road contact. The Hilbert-Huang transform is utilized to extract the relevant vibration components and localize them in the wheel rotation angle domain. The energy of the vibration in the trailing part of the contact is shown to increase in low-friction conditions which can be related to the sliding of the tread part as a result of the shear stresses exceeding the local friction limit. To separate the effect of the surface roughness and the friction, different road surfaces were used in the measurements. In addition, the effects of different driving manoeuvres on the measured accelerations and the propagation of the sliding zone in the contact patch during braking are illustrated.

Detection of the local sliding in the tyre-road contact by measuring vibrations on the inner liner of the tyre

International Nuclear Information System (INIS)

Niskanen, Arto J; Tuononen, Ari J

2017-01-01

Intelligent tyres can provide vital information from the tyre-road contact, especially for autonomous cars and intelligent infrastructure. In this paper, the acceleration measured on the inner liner of a tyre is used to detect the local sliding in the tyre-road contact. The Hilbert–Huang transform is utilized to extract the relevant vibration components and localize them in the wheel rotation angle domain. The energy of the vibration in the trailing part of the contact is shown to increase in low-friction conditions which can be related to the sliding of the tread part as a result of the shear stresses exceeding the local friction limit. To separate the effect of the surface roughness and the friction, different road surfaces were used in the measurements. In addition, the effects of different driving manoeuvres on the measured accelerations and the propagation of the sliding zone in the contact patch during braking are illustrated. (paper)

3D Tyre/Road pavement contact stress measurements

CSIR Research Space (South Africa)

De Beer, Morris

2010-10-01

Full Text Available The CSIR’s proprietary Stress-in-Motion (SIM) measurements provide rational descriptions of 1D, 2D and 3D tyre/road pavement stresses for: Road pavement design testing and evaluation, as well as tyre design, testing and evaluation....

Transmission of vertical soil stress under agricultural tyres

DEFF Research Database (Denmark)

Keller, Thomas; Berli, M.; Ruiz, S.

2014-01-01

and simulate soil stress under defined loads. Stress in the soil profile at 0.3, 0.5 and 0.7 m depth was measured during wheeling at a water content close to field capacity on five soils (13–66% clay). Stress transmission was then simulated with a semi-analytical model, using vertical stress at 0.1 m depth......The transmission of stress induced by agricultural machinery within an agricultural soil is typically modelled on the basis of the theory of stress transmission in elastic media, usually in the semi-empirical form that includes the “concentration factor” (v). The aim of this paper was to measure...... estimated from tyre characteristics as the upper boundary condition, and v was obtained at minimum deviation between measurements and simulations. For the five soils, we obtained an average v of 3.5 (for stress transmitting from 0.1 to 0.7 m depth). This was only slightly different from v = 3 for which...

A Comprehensive Study on Technologies of Tyre Monitoring Systems and Possible Energy Solutions

Directory of Open Access Journals (Sweden)

Ali E. Kubba

2014-06-01

Full Text Available This article presents an overview on the state of the art of Tyre Pressure Monitoring System related technologies. This includes examining the latest pressure sensing methods and comparing different types of pressure transducers, particularly their power consumption and measuring range. Having the aim of this research to investigate possible means to obtain a tyre condition monitoring system (TCMS powered by energy harvesting, various approaches of energy harvesting techniques were evaluated to determine which approach is the most applicable for generating energy within the pneumatic tyre domain and under rolling tyre dynamic conditions. This article starts with an historical review of pneumatic tyre development and demonstrates the reasons and explains the need for using a tyre condition monitoring system. Following this, different tyre pressure measurement approaches are compared in order to determine what type of pressure sensor is best to consider in the research proposal plan. Then possible energy harvesting means inside land vehicle pneumatic tyres are reviewed. Following this, state of the art battery-less tyre pressure monitoring systems developed by individual researchers or by world leading tyre manufacturers are presented. Finally conclusions are drawn based on the reviewed documents cited in this article and a research proposal plan is presented.

Metallurgical investigation of wire breakage of tyre bead grade

Directory of Open Access Journals (Sweden)

Piyas Palit

2015-10-01

Full Text Available Tyre bead grade wire is used for tyre making application. The wire is used as reinforcement inside the polymer of tyre. The wire is available in different size/section such as 1.6–0.80 mm thin Cu coated wire. During tyre making operation at tyre manufacturer company, wire failed frequently. In this present study, different broken/defective wire samples were collected from wire mill for detailed investigation of the defect. The natures of the defects were localized and similar in nature. The fracture surface was of finger nail type. Crow feet like defects including button like surface abnormalities were also observed on the broken wire samples. The defect was studied at different directions under microscope. Different advanced metallographic techniques have been used for detail investigation. The analysis revealed that, white layer of surface martensite was formed and it caused the final breakage of wire. In this present study we have also discussed about the possible reason for the formation of such kind of surface martensite (hard-phase.

Use of rubber shreds to enhance attenuation of railway sub-ballast layers made of unbound aggregates; Uso de partículas de caucho para mejorar la capacidad de atenuación de capas granulares de subbalasto en ferrocarriles

Energy Technology Data Exchange (ETDEWEB)

Hidalgo-Signes, C.; Garzón-Roca, J.; Grima-Palop, J.M.; Insa-Franco, R.

2017-07-01

One of the approaches for solving the problem of induced vibrations in railways is by slightly modifying the materials that form the track. A study is presented of the attenuation capacity of mixes composed of granular soil and rubber shreds when used as sub-ballast (the layer located immediately below the ballast layer). Rubber shreds are obtained from scrap tyres, a troublesome waste material whose reuse and recycling is necessary. A series of mixes of granular soil and rubber shreds with rubber contents of between 1% and 10% are submitted to hammer impact tests to study their response to dynamic excitation. Results reveal that mixing rubber shreds with granular soil increases damping ratios, thus demonstrating the potential of the proposed mixes for attenuating vibration. [Spanish] Una de las posibles formas de resolver el problema de las vibraciones inducidas por el ferrocarril es llevando a cabo una ligera modificación de los materiales que forman la vía. En este artículo, se presenta un estudio de la capacidad de atenuación de mezclas compuestas por zahorras y partículas de caucho para ser usadas como sub-balasto (capa localizada bajo el balasto). Las partículas de caucho se obtienen a partir de neumáticos fuera de uso, un material problemático cuya reutilización y reciclaje es cada vez más necesario. Las mezclas de zahorra-caucho, con un contenido entre el 1% y 10%, se someten a una serie de ensayos dinámicos mediante impacto con martillo, estudiando su respuesta frente a la excitación dinámica. Los resultados revelan que la mezcla de partículas de caucho con zahorras aumenta el coeficiente de amortiguamiento, lo que muestra el potencial que poseen las mezclas propuestas para la atenuación de vibraciones.

Tyre induced vibrations of the car-trailer system

Science.gov (United States)

Beregi, S.; Takács, D.; Stépán, G.

2016-02-01

The lateral and yaw dynamics of the car-trailer combination are analysed by means of a single track model. The equations of motion are derived rigorously by means of the Appell-Gibbs equations for constant longitudinal velocity of the vehicle. The tyres are described with the help of the so-called delayed tyre model, which is based on a brush model with pure rolling contact. The lateral forces and aligning torques of the tyre/road interaction are calculated via the instantaneous lateral deformations in the contact patches. The linear stability analysis of the rectilinear motion is performed via the analytically determined characteristic function of the system. Stability charts are constructed with respect to the vehicle longitudinal velocity and the payload position on the trailer. Self-excited lateral vibrations are detected with different vibration modes at low and at high longitudinal speeds of the vehicle. The effects of the tyre parameters are also investigated.

Full vehicle ABS braking using the SWIFT rigid ring tyre model

NARCIS (Netherlands)

Pauwelussen, J.P.; Gootjes, L.; Schröder, C.; Köhne, K.-U.; Jansen, S.T.H.; Schmeitz, A.J.C.

2003-01-01

In recent years, at the Delft University of Technology and TNO-Automotive and in conjunction with an industrial consortium, a pragmatic tyre model has been developed going by the name SWIFT, which is geared to the analysis of tyre oscillations and its effects on vehicle behaviour. The SWIFT tyre

Development of Low Cost Soil Stabilization Using Recycled Material

Science.gov (United States)

Ahmad, F.; Yahaya, A. S.; Safari, A.

2016-07-01

Recycled tyres have been used in many geotechnical engineering projects such as soil improvement, soil erosion and slope stability. Recycled tyres mainly in chip and shredded form are highly compressible under low and normal pressures. This characteristic would cause challenging problems in some applications of soil stabilization such as retaining wall and river bank projects. For high tensile stress and low tensile strain the use of fiberglass would be a good alternative for recycled tyre in some cases. To evaluate fiberglass as an alternative for recycled tyre, this paper focused on tests of tensile tests which have been carried out between fiberglass and recycled tyre strips. Fibreglass samples were produced from chopped strand fibre mat, a very low-cost type of fibreglass, which is cured by resin and hardener. Fibreglass samples in the thickness of 1 mm, 2 mm, 3 mm and 4 mm were developed 100 mm x 300 mm pieces. It was found that 3 mm fibreglass exhibited the maximum tensile load (MTL) and maximum tensile stress (MTS) greater than other samples. Statistical analysis on 3 mm fibreglass indicated that in the approximately equal MTL fibreglass samples experienced 2% while tyre samples experienced 33.9% ultimate tensile strain (UTST) respectively. The results also showed an approximately linear relationship between stress and strain for fibreglass samples and Young's modulus (E), ranging from 3581 MPa to 4728 MPa.

Shredded banknotes reconstruction using AKAZE points.

Science.gov (United States)

Nabiyev, Vasif V; Yılmaz, Seçkin; Günay, Asuman; Muzaffer, Gül; Ulutaş, Güzin

2017-09-01

Shredded banknote reconstruction is a recent topic and can be viewed as solving large-scale jigsaw puzzles. Also, problems such as reconstruction of fragmented documents, photographs and historical artefacts are closely related with this topic. The high computational complexity of these problems increases the need for the development of new methods Reconstruction of shredded banknotes consists of three main stages. (1) Matching fragments with a reference banknote. (2) Aligning the fragments by rotating at certain angles. (3) Assembling the fragments. The existing methods can successfully applied to synthetic banknote fragments which are created in computer environment. But when real banknote reconstruction problem is considered, different sub problems arise and make the existing methods inadequate. In this study, a keypoint based method, named AKAZE, was used to make the matching process effective. This is the first study that uses the AKAZE method in the reconstruction of shredded banknotes. A new method for fragment alignment has also been proposed. In this method, the convex hulls that contain all true matched AKAZE keypoints were found on reference banknote and fragments. The orientations of fragments were estimated accurately by comparing these convex polygons. Also, a new criterion was developed to reveal the success rates of reconstructed banknotes. In addition, two different data sets including real and synthetic banknote fragments of different countries were created to test the success of proposed method. Copyright © 2017 Elsevier B.V. All rights reserved.

a High-Frequency Three-Dimensional Tyre Model Based on Two Coupled Elastic Layers

Science.gov (United States)

LARSSON, K.; KROPP, W.

2002-06-01

Road traffic noise is today a serious environmental problem in urban areas. The dominating noise source at speeds greater than 50 km/h is car tyres. In order to achieve a reduction of traffic noise tyres have to become quieter. To reduce tyre/road noise a deep understanding of the noise generation mechanisms is of major importance. An existing tyre/road noise simulation model consists of a smooth tyre rolling at a constant speed on a rough road surface. It is composed of three separate modules: a tyre model, a contact model and a radiation model. The major drawback with the contact model is that it only takes the radial component of the contact forces into account. To improve this model, a description of the tangential motion at high frequencies is necessary. Most of the models for the structure-borne sound behaviour of tyres are designed for the low-frequency range (i.e., below 400 Hz). Above this frequency range, the curvature of the tyre is unimportant, while the internal structure (multi-layers of steel and rubber) increases in importance. For the high-frequency range, a double-layer tyre model is proposed, which is based on the general field equations, to take into account the tangential motion and the local deformation of the tread. Both propagating waves and mode shapes have been investigated by the use of this model. Calculations of the response of the tyre to an external excitation show relatively good agreement with measurements on a smooth tyre.

Research of Sustainable Use of Tire Shreds in Landfill

Directory of Open Access Journals (Sweden)

Kristina Bazienė

2016-08-01

Full Text Available Studies are on-going to establish the suitability of tire shreds in the landfill bottom drainage layer, to minimize clogging. Four experimental columns were constructed in which were 500 mm long and 200 mm in diameter. They were filled with different fillers and with a different amount of tire shreds. The most important problem with drainage filler in landfills is clogging. Over long periods of time in landfill operation, the drainage layer clogs (the pores of the layer become smaller and the porosity of the layer becomes smaller. The experiment was carried out for 365 days. Although the landfill for this period represents only one-fiftieth or less of the operation time, the laboratory tests found that the drainage layer bandwidth of reduction in one year can have a negative impact in the long run over time. The main elements that influence the decrease of conductivity are the total suspended solids and calcium and iron compounds. The change of these compounds was observed during the column study, where the concentration of each month in all the columns was decreasing. The results showed that the waste of rubber (tire shreds used for creating fillers in columns provided greater porosity of the layer. It is a beneficial reason to use a rubble and tire shreds waste mix for forming the drainage layer in landfills.

Influence of tyre-road contact model on vehicle vibration response

Science.gov (United States)

Múčka, Peter; Gagnon, Louis

2015-09-01

The influence of the tyre-road contact model on the simulated vertical vibration response was analysed. Three contact models were compared: tyre-road point contact model, moving averaged profile and tyre-enveloping model. In total, 1600 real asphalt concrete and Portland cement concrete longitudinal road profiles were processed. The linear planar model of automobile with 12 degrees of freedom (DOF) was used. Five vibration responses as the measures of ride comfort, ride safety and dynamic load of cargo were investigated. The results were calculated as a function of vibration response, vehicle velocity, road quality and road surface type. The marked differences in the dynamic tyre forces and the negligible differences in the ride comfort quantities were observed among the tyre-road contact models. The seat acceleration response for three contact models and 331 DOF multibody model of the truck semi-trailer was compared with the measured response for a known profile of test section.

Sliding mode-based lateral vehicle dynamics control using tyre force measurements

Science.gov (United States)

Kunnappillil Madhusudhanan, Anil; Corno, Matteo; Holweg, Edward

2015-11-01

In this work, a lateral vehicle dynamics control based on tyre force measurements is proposed. Most of the lateral vehicle dynamics control schemes are based on yaw rate whereas tyre forces are the most important variables in vehicle dynamics as tyres are the only contact points between the vehicle and road. In the proposed method, active front steering is employed to uniformly distribute the required lateral force among the front left and right tyres. The force distribution is quantified through the tyre utilisation coefficients. In order to address the nonlinearities and uncertainties of the vehicle model, a gain scheduling sliding-mode control technique is used. In addition to stabilising the lateral dynamics, the proposed controller is able to maintain maximum lateral acceleration. The proposed method is tested and validated on a multi-body vehicle simulator.

Tyre-road contact using a particle-envelope surface model

Science.gov (United States)

Pinnington, Roger J.

2013-12-01

Determination of the contact forces is the central problem in all aspects of road-tyre interaction: i.e. noise, energy loss and friction. A procedure to find the contact forces under a rolling tyre is presented in four stages. First, the contact stiffness of a uniform peak array from indentations in the rubber tread, and also tyre carcass deflection, is described by some new simplified expressions. Second, a routine divides a single surface profile into equal search intervals, in which the highest peaks are identified. These are used to obtain the parameters for the interval, i.e. the mean envelope and the mean interval. The process is repeated at geometrically decreasing search intervals until the level of the data resolution, thereby describing the profile by a set of envelopes. The ‘strip profile’ ultimately used to describe the surface, is obtained by selecting the highest points across the profiles of one stone's width. The third stage is to combine the strip profile envelopes with the contact stiffness expressions, yielding the nonlinear stiffness-displacement, and force-displacement relationships for the chosen road-tyre combination. Finally the contact pressure distribution from a steady-state rolling tyre model is applied to the strip profile, via the force-displacement relationship, giving the local tyre displacements on the road texture. This displacement pattern is shown to be proportional to the time and space varying contact pressure, which then is incorporated into a wave equation for rolling contact.

Study of carbon black obtained by pyrolysis of waste scrap tyres

Czech Academy of Sciences Publication Activity Database

Mikulová, Z.; Šeděnková, Ivana; Matějová, Lenka; Večeř, M.; Dombek, V.

2013-01-01

Roč. 111, č. 2 (2013), s. 1475-1481 ISSN 1388-6150. [Central and Eastern European Conference on Thermal Analysis and Calorimetry /1./ - CEEC-TAC1. Craiova, 07.09.2011-10.09.2011] R&D Projects: GA ČR GA104/09/0972 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z40720504 Keywords : scrap tyres * carbon black * thermogravimetry Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.206, year: 2013

Experimental investigation of tread wear and particle emission from tyres with different treadwear marking

Science.gov (United States)

Grigoratos, Theodoros; Gustafsson, Mats; Eriksson, Olle; Martini, Giorgio

2018-06-01

The Treadwear Rating (TWR) provided on the sidewall of the tyre is a marking intended to inform the customer about the expected durability of the tyre. The current study explores whether there is a correlation between the TWR and tyres' tread mass loss. Furthermore, it explores the possible correlation between the TWR and tyre wear dust emitted in the form of PM10 and PM2.5. For that reason, two tyres of the same brand (B) but with different TWR and three tyres of different brands (C and D with the same TWR as one of the B tyres and A with a lower TWR) were tested at a constant speed of 70 km/h by means of the Swedish National Road and Transport Research Institute (VTI) road simulator. Tyres of the same TWR but of different brands showed different behaviour in terms of material loss, PM, and PN emissions under the selected testing conditions. This means that it is not feasible to categorize tyres of different brands in terms of their emissions based on their TWR. The test performed on the two tyres of the same brand but with different TWR showed instead a substantial (not statistically significant) difference in both total wear and PM10 emissions. The tyre with the higher TWR (B2) showed less wear and PM10 emissions compared to the B1 tyre having a lower TWR. Since only two tyres of the same brand and with different TWR were tested, this result cannot be generalized and more tests are necessary to confirm the relation within the same brand. In general, the tyre tread mass loss showed no obvious statistical relation to PM10, PM2.5 or PN concentration. In all cases approximately 50% (by mass) of emitted PM10 fall within the size range of fine particles, while PN size distribution is dominated by nanoparticles most often peaking at 20-30 nm.

Clays in natural and engineered barriers for radioactive waste confinement - 4. International meeting. Book of abstracts

International Nuclear Information System (INIS)

2010-01-01

The 4. edition of the International Meeting 'Clays in Natural and Engineered Barriers for Radioactive Waste Confinement' took place at the 'Cite Internationale des Congres' of Nantes (France). Approximately 500 participants (from about 20 different countries) attended the meeting. All the abstracts (oral and poster sessions) are included in these proceedings. The purpose of this 4. international conference is to gather specialists in the different disciplines related to clays and clay minerals, with scientists from organisations engaged in radioactive waste disposal, in order to evaluate the progress of the research conducted in that field. Multidisciplinary approaches including geology, mineralogy, geochemistry, rheology, geomechanics of clays are required in order to provide a detailed characterisation of the geological host formations considered for the disposal of radioactive waste and to assess the behaviour of engineered and natural barriers when submitted to various types of perturbations induced by disposal facilities. The major objectives for the experimental programs are constituted by the performance evaluation for the natural barrier as well as the impact of repository-induced disturbances upon the confinement properties of clay-rich geological formations. This is being or will be conducted in underground research laboratories, for interpreting the subsequent scientific results, for modelling the long-term behaviour of radioactive waste repositories and for carrying out safety assessment exercises. This conference covers all the aspects of clay characterisation and behaviour relevant to the confinement of radionuclides in clay, considered at various time scales and locations, from the descriptions of basic phenomenological processes to the global understanding of the performance and safety at repository and geological scales. Most of the topics covered by the programme of the conference are in line with the general objectives

The measurement of dynamic radii for passenger car tyre

Science.gov (United States)

Anghelache, G.; Moisescu, R.

2017-10-01

The tyre dynamic rolling radius is an extremely important parameter for vehicle dynamics, for operation of safety systems as ESP, ABS, TCS, etc., for road vehicle research and development, as well as for validation or as an input parameter of automotive simulations and models. The paper investigates the dynamic rolling radii of passenger car tyre and the influence of rolling speed and inflation pressure on their magnitude. The measurement of dynamic rolling radii has been performed on a chassis dynamometer test rig. The dynamic rolling radii have been measured indirectly, using longitudinal rolling speed and angular velocity of wheel. Due to the subtle effects that the parameters have on rolling radius magnitude, very accurate equipment has to be used. Two different methods have been chosen for measuring the wheel angular velocity: the stroboscopic lamp and the incremental rotary encoder. The paper shows that the stroboscopic lamp has an insufficient resolution, therefore it was no longer used for experimental investigation. The tyre dynamic rolling radii increase with rolling speed and with tyre inflation pressure, but the effect of pressure is more significant. The paper also makes considerations on the viability of simplified formulae from literature for calculating the tyre dynamic rolling radius.

Molecular Basis of Clay Mineral Structure and Dynamics in Subsurface Engineering Applications

Science.gov (United States)

Cygan, R. T.

2015-12-01

Clay minerals and their interfaces play an essential role in many geochemical, environmental, and subsurface engineering applications. Adsorption, dissolution, precipitation, nucleation, and growth mechanisms, in particular, are controlled by the interplay of structure, thermodynamics, kinetics, and transport at clay mineral-water interfaces. Molecular details of these processes are typically beyond the sensitivity of experimental and analytical methods, and therefore require accurate models and simulations. Also, basal surfaces and interlayers of clay minerals provide constrained interfacial environments to facilitate the evaluation of these complex processes. We have developed and used classical molecular and quantum methods to examine the complex behavior of clay mineral-water interfaces and dynamics of interlayer species. Bulk structures, swelling behavior, diffusion, and adsorption processes are evaluated and compared to experimental and spectroscopic findings. Analysis of adsorption mechanisms of radionuclides on clay minerals provides a scientific basis for predicting the suitability of engineered barriers associated with nuclear waste repositories and the fate of contaminants in the environment. Similarly, the injection of supercritical carbon dioxide into geological reservoirs—to mitigate the impact of climate change—is evaluated by molecular models of multi-fluid interactions with clay minerals. Molecular dynamics simulations provide insights into the wettability of different fluids—water, electrolyte solutions, and supercritical carbon dioxide—on clay surfaces, and which ultimately affects capillary fluid flow and the integrity of shale caprocks. This work is supported as part of Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science and by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Geosciences Research Program

Waste Tyres as Heat Sink to Reduce the Driveway Surface Temperatures in Malaysia

Directory of Open Access Journals (Sweden)

Aniza Abdul Aziz

2013-12-01

Full Text Available The development of roads and driveways are on the rise as automobiles are now a necessity to all. This excessive development with its requirements increased the urban heat temperature and the generation of waste tyres. Waste tyre management has therefore been taken seriously by developed countries and since the European directive to ban used tyre products and whole tire disposal from landfill in 2003 and 2006 respectively, many researchers have looked for alternative ways to use the waste tyre. In Malaysia, The Smart and Cool Home Developer attempted to develop an eco-house by utilising waste tyre as the foundation for the driveway and claimed that the buried tyres act as a heat sink for the concrete and reduce the surface temperature of the driveway. Hence investigations were conducted on two sample houses to investigate this phenomenon. Findings from this pilot study show that waste tyres do act as a heat sink to the concrete driveways which affect the ambient temperature and relative humidity of the immediate surroundings.

Scrap Tyre Management Pathways and Their Use as a Fuel—A Review

Directory of Open Access Journals (Sweden)

Amir Rowhani

2016-10-01

Full Text Available This article provides a review of different methods for managing waste tyres. Around 1.5 billion scrap tyres make their way into the environmental cycle each year, so there is an extreme demand to manage and mitigate the environmental impact which occurs from landfilling and burning. Numerous approaches are targeted to recycle and reuse the tyre rubber in various applications. Among them, one of the most important methods for sustainable environmental stewardship is converting tyre rubber components into bio-oil. In this study, scrap tyre management techniques including landfill, retreading, recycling, combustion, and conversion to liquid fuels was reviewed (including gasification, hydrothermal liquefaction, and pyrolysis. The effects of parameters such as reactor types, pyrolysis temperature, and catalyst on the oil, gas and solid products in pyrolysis process were investigated.

Treatment and disposal of tyres: Two EU approaches. A review.

Science.gov (United States)

Torretta, Vincenzo; Rada, Elena Cristina; Ragazzi, Marco; Trulli, Ettore; Istrate, Irina Aura; Cioca, Lucian Ionel

2015-11-01

The treatment and disposal of tyres from vehicles has long been of considerable environmental importance. The main problem lies in the mixed composition of the tyres. Studies have been undertaken to modify the structure of the tyres, especially with reference to the percentage of granulated rubber incorporated, in order to improve their performance, and also to reduce their environmental impact during normal functioning (noise, particulates, etc.) and facilitate recycling and final disposal. The aim of the present study is to review and compare how used tyres are treated and disposed of in two different EU countries. The first is Italy, which has been part of the European Union since its inception, and has important industrial traditions. The second is Romania, an emerging country which recently became part of the EU, and whose economic and industrial development has had a major boost in recent years, with a strong growth in waste production, together with consumption in urban areas. The occasion was useful to consider the situation concerning the evolution of the different aspects related to the management of the end-of-life tyres. In particular, the paper considers the properties of tyre waste and their potential reuse, the enhancement of end-of-life tires and the various types of recovery, such as the reconstruction of tyres and the material recovery. The aspects related to the energy recovery and the use of the life cycle analysis, as a tool to support the choices of the best management system, were also taken into consideration, not forgetting that an adequate end-of-life planning is important when developing a sustainable product, since it can affect considerably its overall life cycle. Copyright © 2015 Elsevier Ltd. All rights reserved.

Tyre-pavement interface contact stresses on flexible pavements - quo vadis?

CSIR Research Space (South Africa)

De Beer, Morris

2004-09-01

Full Text Available on tyre inflation pressure on this route is also given. The paper also discusses an improved definition of the actual tyre/pavement interaction of modern heavy vehicles and their loads on the current flexible road infrastructure....

Reconsideration of tyre-pavement input parameters for the structural design of flexible pavements

CSIR Research Space (South Africa)

De Beer, Morris

2006-08-01

Full Text Available of modern truck tyres. Tyre-pavement contact stress measurements were carried out on a busy national road (N3) in South Africa from the port of Durban to the inland province of Gauteng. The three-dimensional tyre-pavement contact stress regimes of 45 227...

Stochastic road excitation and control feasibility in a 2D linear tyre model

Science.gov (United States)

Rustighi, E.; Elliott, S. J.

2007-03-01

For vehicle under normal driving conditions and speeds above 30-40 km/h the dominating internal and external noise source is the sound generated by the interaction between the tyre and the road. This paper presents a simple model to predict tyre behaviour in the frequency range up to 400 Hz, where the dominant vibration is two dimensional. The tyre is modelled as an elemental system, which permits the analysis of the low-frequency tyre response when excited by distributed stochastic displacements in the contact patch. A linear model has been used to calculate the contact forces from the road roughness and thus calculate the average spectral properties of the resulting radial velocity of the tyre in one step from the spectral properties of the road roughness. Such a model has also been used to provide an estimate of the potential effect of various active control strategies for reducing the tyre vibrations.

Study on some safety-related aspects of tyre use

NARCIS (Netherlands)

Jansen, S.T.H.; Schmeitz, A.J.C.; Maas, S.; Rodarius, C.; Akkermans, L.

2014-01-01

The tyre is a key component that affects road safety. The European commission has posted a tender aimed to study what measures on a European level can be taken in relation to the use of tyres to improve road safety. The results of this study, supported by a cost benefit analyses and carried out by

Interaction processes governing friction between tyre and road; Wechselwirkungen im Prozess der Reibung zwischen Reifen und Fahrbahn

Energy Technology Data Exchange (ETDEWEB)

Bachmann, T.

1998-12-31

Friction between tyre and road is influenced by tyre and road parameters as well as, in some instances, by water or snow/ice. The dissertation investigates the interdependences between these influencing parameters. Experimental investigations on friction-slip curves of modern car tyres on real roads provide deeper knowledge on power transfer mechanisms. Apart from the contact conditions, also the viscoelastic properties of tyre materials with silica gel as filler material were investigated, with particular emphasis on the velocity dependence of the friction coefficient. The findings are presented in the form of velocity/slip characteristic fields of the friction coefficient measured on different surface types and are interpreted on the basis of the rubber friction theory. The interdisciplinary character of the investigations makes the dissertation interesting for experts in car engineering, roadway construction and tyre research and development. [Deutsch] Der Kraftschluss zwischen Reifen und Fahrbahn wird durch Einflussgroessen bestimmt, die sich dem Reifen und der Fahrbahn, eventuell vorhandenem Wasser oder Schnee/Eis zuordnen lassen. Zwischen diesen sich ueberlagernden Einflussgroessen gibt es eine Vielzahl von Wechselwirkungen, die in dieser Dissertation analysiert werden. Die experimentelle Untersuchung der Reibwert-Schlupf-Kurven moderner Pkw-Reifen auf realen Fahrbahnen erweitert das Verstaendnis fuer die Kraftuebertragungsmechanismen. Neben einer Betrachtung der Kontaktverhaeltnisse werden visko-elastische Eigenschaften von Reifenmischungen auch mit dem Fuellstoff Kieselsaeure untersucht. Vor allem die Geschwindigkeitsabhaengigkeit des Reibwertes wird behandelt. Als Ergebnis werden die Wechselwirkungen in Form von auf verschiedenen Oberflaechen gemessenen Geschwindigkeits-Schlupf-Kennfeldern des Reibwerts beschrieben und mit der Gummireibungstheorie interpretiert. Die Arbeit wendet sich wegen des interdisziplinaeren Charakters des Themas an Angehoerige der

Tyre-road Interaction: a holistic approach to noise and rolling resistance

OpenAIRE

Vieira, Tiago

2018-01-01

Energy dissipation, fuel consumption, real-estate property prices and health issues are some of the aspects related to the tyre/pavement interaction and its functional properties of rolling resistance and noise. The first two aspects are affected by the tyre/road interaction as energy is dissipated mostly by hysteretic losses as the tyre is subjected to dynamic deformations when contacting the pavement surface. The other effect of this contact system that is analysed in this thesis is noise. ...

Impact of Pretreatment and Drying Methods on Quality Attributes of Onion Shreds

Directory of Open Access Journals (Sweden)

Nihar R. Sahoo

2015-01-01

Full Text Available Experiments were conducted on dry untreated onion shreds (2 mm thickness or treated with salt (5 % solution and potassium metabisulphite (0.5 % solution in convective drier at 50 °C ((46±4 % relative humidity (RH, 55 °C ((35±4 % RH, 60 °C ((28±4 % RH and 65 °C ((20±4 % RH, heat pump-assisted convective drier at 35 °C ((32±2 % RH, 40 °C ((26±2 % RH, 45 °C ((19±2 % RH and 50 °C ((15±2 % RH and microwave-assisted convective drier at four microwave power levels, i.e. 120, 240, 360 and 480 W. The quality parameters of the dried onion shreds, namely rehydration ratio, colour diff erence, pyruvic and ascorbic acid contents and sensory scores were evaluated. The quality of dehydrated onion shreds was observed to be comparatively better when treated in heat pump drier at 50 °C, followed by that in microwave-assisted convective drier at 240 W and 50 °C, and last in convective drier at 60 °C. The onion shreds pretreated with potassium metabisulphite retained better colour of the dried product irrespective of drying methods. Therefore, heat pump drying may be recommended as one of the best drying methods for onion shreds, because it maintains the fi nal product quality, which has practical importance for the food industry.

An Improved Optimal Slip Ratio Prediction considering Tyre Inflation Pressure Changes

Directory of Open Access Journals (Sweden)

Guoxing Li

2015-01-01

Full Text Available The prediction of optimal slip ratio is crucial to vehicle control systems. Many studies have verified there is a definitive impact of tyre pressure change on the optimal slip ratio. However, the existing method of optimal slip ratio prediction has not taken into account the influence of tyre pressure changes. By introducing a second-order factor, an improved optimal slip ratio prediction considering tyre inflation pressure is proposed in this paper. In order to verify and evaluate the performance of the improved prediction, a cosimulation platform is developed by using MATLAB/Simulink and CarSim software packages, achieving a comprehensive simulation study of vehicle braking performance cooperated with an ABS controller. The simulation results show that the braking distances and braking time under different tyre pressures and initial braking speeds are effectively shortened with the improved prediction of optimal slip ratio. When the tyre pressure is slightly lower than the nominal pressure, the difference of braking performances between original optimal slip ratio and improved optimal slip ratio is the most obvious.

Shrinkage Behaviour of Fibre Reinforced Concrete with Recycled Tyre Polymer Fibres

Directory of Open Access Journals (Sweden)

Marijana Serdar

2015-01-01

Full Text Available Different types of fibres are often used in concrete to prevent microcracking due to shrinkage, and polypropylene fibres are among the most often used ones. If not prevented, microcracks can lead to the development of larger cracks as drying shrinkage occurs, enabling penetration of aggressive substances from the environment and reducing durability of concrete structures. The hypothesis of the present research is that polypropylene fibres, used in concrete for controlling formation of microcracks due to shrinkage, can be replaced with recycled polymer fibres obtained from end-of-life tyres. To test the hypothesis, concrete mixtures containing polypropylene fibres and recycled tyre polymer fibres were prepared and tested. Experimental programme focused on autogenous, free, and restrained shrinkage. It was shown that PP fibres can be substituted with higher amount of recycled tyre polymer fibres obtaining concrete with similar shrinkage behaviour. The results indicate promising possibilities of using recycled tyre polymer fibres in concrete products. At the same time, such applications would contribute to solving the problem of waste tyre disposal.

Effect of by-product steel slag on the engineering properties of clay soils

Directory of Open Access Journals (Sweden)

Faisal I. Shalabi

2017-10-01

Full Text Available Clay soils, mainly if they contain swelling minerals such as smectite or illite, may cause severe damage to structures, especially when these soils are subjected to wetting and drying conditions. High expansion and reduction in shear strength and foundation bearing capacity will take place due to the increase in water content of these soils. The engineering properties of these kinds of soils can be improved by using additives and chemical stabilizers. In this work, by-product steel slag was used to improve the engineering properties of clay soils. Lab and field experimental programs were developed to investigate the effect of adding different percentages of steel slag on plasticity, swelling, compressibility, shear strength, compaction, and California bearing ratio (CBR of the treated materials. The results of tests on the clay soil showed that as steel slag content increased, the soil dry density, plasticity, swelling potential, and cohesion intercept decreased and the angle of internal friction increased. For the CBR, the results of the tests showed an increase in the CBR value with the increase in slag content.

76 FR 81468 - Notice of Decision to Authorize the Importation of Shredded Lettuce From Egypt Into the...

Science.gov (United States)

2011-12-28

...] Notice of Decision to Authorize the Importation of Shredded Lettuce From Egypt Into the Continental... fresh shredded lettuce from Egypt. Based on the findings of a pest risk analysis, which we made... introducing or disseminating plant pests or noxious weeds via the importation of fresh shredded lettuce from...

Shear forces in the contact patch of a braked-racing tyre

Science.gov (United States)

Gruber, Patrick; Sharp, Robin S.

2012-12-01

This article identifies tyre modelling features that are fundamental to the accurate simulation of the shear forces in the contact patch of a steady-rolling, slipping and cambered racing tyre. The features investigated include contact patch shape, contact pressure distribution, carcass flexibility, rolling radius (RR) variations and friction coefficient. Using a previously described physical tyre model of modular nature, validated for static conditions, the influence of each feature on the shear forces generated is examined under different running conditions, including normal loads of 1500, 3000 and 4500 N, camber angles of 0° and-3°, and longitudinal slip ratios from 0 to-20%. Special attention is paid to heavy braking, in which context the aligning moment is of great interest in terms of its connection with the limit-handling feel. The results of the simulations reveal that true representations of the contact patch shape, carcass flexibility and lateral RR variation are essential for an accurate prediction of the distribution and the magnitude of the shear forces generated at the tread-road interface of the cambered tyre. Independent of the camber angle, the contact pressure distribution primarily influences the shear force distribution and the slip characteristics around the peak longitudinal force. At low brake-slip ratios, the friction coefficient affects the shear forces in terms of their distribution, while, at medium to high-slip ratios, the force magnitude is significantly affected. On the one hand, these findings help in the creation of efficient yet accurate tyre models. On the other hand, the research results allow improved understanding of how individual tyre components affect the generation of shear forces in the contact patch of a rolling and slipping tyre.

Computational Analysis of a South African Mobile Trailer-Type Medium Sized Tyre Test Rig

CSIR Research Space (South Africa)

Sharma, Shikar

2015-04-01

Full Text Available To support the South African National Defence Force with their vehicle mobility needs, the CSIR has begun characterising tyres by using a medium, trailer-type, tyre test rig. Two different Pacejka tyre models were generated using two independent...

The local effects of friction between the tyre and the road; Lokale Effekte der Reibung zwischen Pkw-Reifen und Fahrbahn

Energy Technology Data Exchange (ETDEWEB)

Fach, M. [DaimlerChrysler AG (Germany). Center Aktive Sicherheit/Fahrdynamik

2000-08-01

The article examines the local effects of friction between passenger car tyres and the road, the deformation of the tread elements and the local slip between the tyre rubber and the road surface. These two movements determine to a great extent the frictional process which allows force to be transmitted from the tyre to the road surface in both a longitudinal and a transverse direction. The report summarises the results of a dissertation based on research carried out at the Department of Automotive Enginering at Darmstadt University of Technology. (orig.) [German] Der Beitrag beschaeftigt sich mit den lokalen Effekten der Reibung zwischen Pkw-Reifen und Fahrbahn, den Profilelementverformungen des Laufstreifens und den Gleitbewegungen zwischen dem Reifengummi und der Fahrbahnoberflaeche. Diese beiden Bewegungen bestimmen massgeblich den Reibprozess, der die Kraftuebertragung vom Reifen auf die Strasse sowohl in Laengs- als auch in Querrichtung moeglich macht. Der Bericht fasst die Ergebnisse einer Dissertation zusammen, die am Fachgebiet Fahrzeugtechnik der TU Darmstadt durchgefuehrt wurde. (orig.)

Green's functions for a rotating tyre: a semi-analytical approach

NARCIS (Netherlands)

Lopez Arteaga, I.; Kersjes, S.H.M.; Roozen, N.B.; Schmeitz, A.J.C.; Nijmeijer, H.

2006-01-01

Road traffic noise is becoming an increasingly big problem in densely populated areas. One of the main contributions comes from the tyre/road interaction. For the interior noise, to which the occupants of the vehicle are exposed, tyre/road noise is also an important source, especially at lower

Hg L3 XANES Study of Mercury Methylation in Shredded Eichhornia Crassipes

International Nuclear Information System (INIS)

Rajan, M.; Darrow, J.; Hua, M.; Barnett, B.; Mendoza, M.; Greenfield, B.K.; Andrews, J.C.

2008-01-01

Eichhornia crassipes (water hyacinth) is a non-native plant found in abundance in the Sacramento-San Joaquin River Delta (hereafter called Delta). This species has become a problem, clogging waterways and wetlands. Water hyacinth are also known to accumulate mercury. Recent attempts to curb its proliferation have included shredding with specialized boats. The purpose of this research is to better understand the ability of water hyacinth to phytoremediate mercury and to determine the effect of shredding and anoxic conditions on mercury speciation in plant tissue. In the field assessment, total mercury levels in sediment from the Dow Wetlands in the Delta were found to be 0.273 ± 0.070 ppm Hg, and levels in hyacinth roots and shoots from this site were 1.17 ± 0.08 ppm and 1.03 ± 0.52 ppm, respectively, indicating bioaccumulation of mercury. Plant samples collected at this site were also grown in nutrient solution with 1 ppm HgCl 2 under (1) aerobic conditions, (2) anaerobic conditions, and (3) with shredded plant material only. The greatest accumulation was found in the roots of whole plants. Plants grown in these conditions were also analyzed at Stanford Synchrotron Radiation Laboratory using Hg L 3 X-ray Absorption Near Edge Spectroscopy (XANES), a method to examine speciation that is element-specific and noninvasive. Least-squares fitting of the XANES data to methylated and inorganic mercury(II) model compounds revealed that in plants grown live and aerobically, 5 ± 3% of the mercury was in the form of methylmercury, in a form similar to methylmercury cysteine. This percentage increased to 16 ± 4% in live plants grown anaerobically and to 22 ± 6% in shredded anaerobic plants. We conclude that shredding of the hyacinth plants and, in fact, subjection of plants to anaerobic conditions (e.g., as in normal decay, or in crowded growth conditions) increases mercury methylation. Mechanical removal of the entire plant is significantly more expensive than shredding

Holocene morphogenesis of Alexander the Great's isthmus at Tyre in Lebanon

Science.gov (United States)

Marriner, Nick; Morhange, Christophe; Meulé, Samuel

2007-05-01

In 332 B.C., Alexander the Great constructed an ≈1,000-m-long causeway to seize the offshore island of Tyre. The logistics behind this engineering feat have long troubled archaeologists. Using the Holocene sedimentary record, we demonstrate that Alexander's engineers cleverly exploited a shallow proto-tombolo, or sublittoral sand spit, to breach the offshore city's defensive impregnability. We elucidate a three-phase geomorphological model for the spit's evolution. Settled since the Bronze Age, the area's geological record manifests a long history of natural and anthropogenic forcings. (i) Leeward of the island breakwater, the maximum flooding surface (e.g., drowning of the subaerial land surfaces by seawater) is dated ≈8000 B.P. Fine-grained sediments and brackish and marine-lagoonal faunas translate shallow, low-energy water bodies at this time. Shelter was afforded by Tyre's elongated sandstone reefs, which acted as a 6-km natural breakwater. (ii) By 6000 B.P., sea-level rise had reduced the dimensions of the island from 6 to 4 km. The leeward wave shadow generated by this island, allied with high sediment supply after 3000 B.P., culminated in a natural wave-dominated proto-tombolo within 1-2 m of mean sea level by the time of Alexander the Great (4th century B.C.). (iii) After 332 B.C., construction of Alexander's causeway entrained a complete anthropogenic metamorphosis of the Tyrian coastal system.

Holocene morphogenesis of Alexander the Great's isthmus at Tyre in Lebanon.

Science.gov (United States)

Marriner, Nick; Morhange, Christophe; Meulé, Samuel

2007-05-29

In 332 B.C., Alexander the Great constructed an approximately 1,000-m-long causeway to seize the offshore island of Tyre. The logistics behind this engineering feat have long troubled archaeologists. Using the Holocene sedimentary record, we demonstrate that Alexander's engineers cleverly exploited a shallow proto-tombolo, or sublittoral sand spit, to breach the offshore city's defensive impregnability. We elucidate a three-phase geomorphological model for the spit's evolution. Settled since the Bronze Age, the area's geological record manifests a long history of natural and anthropogenic forcings. (i) Leeward of the island breakwater, the maximum flooding surface (e.g., drowning of the subaerial land surfaces by seawater) is dated approximately 8000 B.P. Fine-grained sediments and brackish and marine-lagoonal faunas translate shallow, low-energy water bodies at this time. Shelter was afforded by Tyre's elongated sandstone reefs, which acted as a 6-km natural breakwater. (ii) By 6000 B.P., sea-level rise had reduced the dimensions of the island from 6 to 4 km. The leeward wave shadow generated by this island, allied with high sediment supply after 3000 B.P., culminated in a natural wave-dominated proto-tombolo within 1-2 m of mean sea level by the time of Alexander the Great (4th century B.C.). (iii) After 332 B.C., construction of Alexander's causeway entrained a complete anthropogenic metamorphosis of the Tyrian coastal system.

Anaerobic co-digestion of sewage sludge with shredded grass from public green spaces.

Science.gov (United States)

Hidaka, Taira; Arai, Sayuri; Okamoto, Seiichiro; Uchida, Tsutomu

2013-02-01

Adding greenery from public spaces to the co-digestion process with sewage sludge was evaluated by shredding experiments and laboratory-scale batch and continuous mesophilic anaerobic fermentation experiments. The ratio of the shredded grass with 20mm or less in length by a commercially available shredder was 93%. The methane production was around 0.2NL/gVS-grass in the batch experiment. The continuous experiment fed with sewage sludge and shredded grass was stably operated for 81days. The average methane production was 0.09NL/gVS-grass when the TS ratio of the sewage sludge and the grass was 10:1. This value was smaller than those of other reports using grass silage, but the grass species in this study were not managed, and the collected grass was just shredded and not ensiled before feeding to the reactor for simple operation. The addition of grass to a digester can improve the carbon/nitrogen ratio, methane production and dewaterability. Copyright © 2013 Elsevier Ltd. All rights reserved.

The influence of tyre characteristics on measures of rolling performance during cross-country mountain biking.

Science.gov (United States)

Macdermid, Paul William; Fink, Philip W; Stannard, Stephen R

2015-01-01

This investigation sets out to assess the effect of five different models of mountain bike tyre on rolling performance over hard-pack mud. Independent characteristics included total weight, volume, tread surface area and tread depth. One male cyclist performed multiple (30) trials of a deceleration field test to assess reliability. Further tests performed on a separate occasion included multiple (15) trials of the deceleration test and six fixed power output hill climb tests for each tyre. The deceleration test proved to be reliable as a means of assessing rolling performance via differences in initial and final speed (coefficient of variation (CV) = 4.52%). Overall differences between tyre performance for both deceleration test (P = 0.014) and hill climb (P = 0.032) were found, enabling significant (P < 0.0001 and P = 0.049) models to be generated, allowing tyre performance prediction based on tyre characteristics. The ideal tyre for rolling and climbing performance on hard-pack surfaces would be to decrease tyre weight by way of reductions in tread surface area and tread depth while keeping volume high.

Improved performance evaluation of road pavements by using measured tyre loading

CSIR Research Space (South Africa)

Maina, JW

2008-11-01

Full Text Available This paper presents evaluation of road pavement response under the loading of typical dual and single truck tyre configurations. Locally developed Stress-In-Motion (SIM) technology was used to quantify three-dimensional (3D) shapes of the tyre road...

Time, tire measurements forces and moments: a new standard for steady state cornering tyre testing

NARCIS (Netherlands)

Oosten, J.J.M. van; Savi, C.; Augustin, M.; Bouhet, O.; Sommer, J.; Colinot, J.P.

1999-01-01

In order to develop vehicles which have maximum active safety, car manufacturers need information about the so-called force and moment properties of tyres. Vehicle manufacturers, tyre suppliers and automotive research organisations have advanced test equipment to measure the forces between a tyre

A method and device for checking the adherence of canvas to rubber in tyres

International Nuclear Information System (INIS)

Boutaine, J.-L.; Courtois, Guy; Tanguy, J.-C.

1973-01-01

Description is given of a method for determining whether a pneumatic tyre comprises separation areas between rubber and canvas or highly-porous zones. A gamma-ray-emitting radioactive gas is injected under pressure into the tyre, and at least one radiation detector is moved along the tyre surface. This can be applied to aeronautics [fr

The tyre - source of information for driver assistance; Der Reifen - Informationsquelle zur Fahrerassistenz

Energy Technology Data Exchange (ETDEWEB)

Holtschulze, J.; Goertz, H. [Inst. fuer Kraftfahrwesen, RWTH Aachen (Germany); Wunderlich, H.; Maeckle, G. [DaimlerChrysler AG, Stuttgart (Germany); Varpula, T. [VTT Automation, Espoo (Finland); Mancosu, F. [Pirelli S.p.A., Mailand (Italy)

2004-07-01

apollo is a research project funded by the European Commission under the 5th Framework Programme ''information society technologies'' (IST). The objective is to develop a prototype of an intelligent tyre. The overall goals are to increase traffic safety and enable improvements for vehicle dynamics control, advanced driver assistance systems and services for external users by providing data on the tyre and the local tyre-road contact. The basics of the tyre deformation behaviour in operation situations show possibilities which signals can be measured and how to derive a set of data for the applications. Free rolling, cornering and braking/driving have to be distinguished. Optimal sensor locations are studied and determined in order to measure deformation characteristics by different quantities such as accelerations. Acquired signals are processed using models of tyre and vehicle behaviour before they are provided to application systems. To transmit the sensor data to the vehicle controller a wireless communication and power supply system is used. (orig.)

Effect of moderate pressure treatments on microstructure, texture, and sensory properties of stirred-curd cheddar shreds.

Science.gov (United States)

Serrano, J; Velazquez, G; Lopetcharat, K; Ramírez, J A; Torres, J A

2004-10-01

A moderate high-pressure processing (HPP) treatment is proposed to accelerate the shredability of Cheddar cheese. High pressure processing (345 and 483 MPa for 3 and 7 min) applied to unripened (1 d old) stirred-curd Cheddar cheese yielded microstructure changes that differed with pressure level and processing time. Untreated and pressure-treated cheese shredded at d 27 and 1, respectively, shared similar visual and tactile sensory properties. The moderate (345 MPa) and the higher (483 MPa) pressure treatments reduced the presence of crumbles, increased mean shred particle length, improved length uniformity, and enhanced surface smoothness in shreds produced from unripened cheese. High-pressure processing treatments did not affect the mechanical properties of ripened cheese or the proteolytic susceptibility of milk protein. It was concluded that a moderate HPP treatment could allow processors to shred Cheddar cheese immediately after block cooling, reducing refrigerated storage costs, with expected savings of over 15 US dollars/1000 lb cheese, and allowing fewer steps in the handling of cheese blocks produced for shredding.

Poro-elasto-plastic behaviour of dry compacted Fo-Ca clay: experiment and modelling. Application to the re-saturation of an engineered clay barrier

International Nuclear Information System (INIS)

Lassabatere, Th.; Imbert, Ch.; Etile, M.A.

1999-01-01

Many projects of underground repositories for high level radioactive waste involve an engineered clay barrier, placed between the waste canister and the surrounding rock. When hydrated, this barrier seals the gap and provides a good watertightness. The natural clay powder, dried and compacted, exhibits hydro-mechanical couplings during the hydration. Such a coupled behaviour, interesting for the industrial application, has been clearly demonstrated by many studies and laboratory experiments. But the modelling of this behaviour, in order to predict the hydration of the clay barrier, is difficult. A coupled modelling, based, at a macroscopic scale, on the thermodynamics of unsaturated porous media, is proposed. This thermodynamical model founds a general framework for non linear poro-elastic and poro-elasto-plastic coupled behaviours. The symmetries of this coupling, induced by this thermodynamical framework, let us take into account the often neglected influence of the mechanical state on the hydraulic problem of the re-saturation of the clay. The complete resolution of the flow problem, coupled with the mechanical behaviour, leads us to study the influence of the rheological behaviour chosen for the clay (elastic - linear or no linear -, or elastoplastic) on the evaluation of the duration of the re-saturation of the clay barrier). (authors)

Wear and Tear of Tyres: A Stealthy Source of Microplastics in the Environment.

Science.gov (United States)

Kole, Pieter Jan; Löhr, Ansje J; Van Belleghem, Frank G A J; Ragas, Ad M J

2017-10-20

Wear and tear from tyres significantly contributes to the flow of (micro-)plastics into the environment. This paper compiles the fragmented knowledge on tyre wear and tear characteristics, amounts of particles emitted, pathways in the environment, and the possible effects on humans. The estimated per capita emission ranges from 0.23 to 4.7 kg/year, with a global average of 0.81 kg/year. The emissions from car tyres (100%) are substantially higher than those of other sources of microplastics, e.g., airplane tyres (2%), artificial turf (12-50%), brake wear (8%) and road markings (5%). Emissions and pathways depend on local factors like road type or sewage systems. The relative contribution of tyre wear and tear to the total global amount of plastics ending up in our oceans is estimated to be 5-10%. In air, 3-7% of the particulate matter (PM 2.5 ) is estimated to consist of tyre wear and tear, indicating that it may contribute to the global health burden of air pollution which has been projected by the World Health Organization (WHO) at 3 million deaths in 2012. The wear and tear also enters our food chain, but further research is needed to assess human health risks. It is concluded here that tyre wear and tear is a stealthy source of microplastics in our environment, which can only be addressed effectively if awareness increases, knowledge gaps on quantities and effects are being closed, and creative technical solutions are being sought. This requires a global effort from all stakeholders; consumers, regulators, industry and researchers alike.

76 FR 50992 - Notice of Availability of a Pest Risk Analysis for the Importation of Shredded Lettuce From Egypt

Science.gov (United States)

2011-08-17

...] Notice of Availability of a Pest Risk Analysis for the Importation of Shredded Lettuce From Egypt AGENCY... into the continental United States of fresh shredded lettuce from Egypt. Based on this analysis, we... fresh shredded lettuce from Egypt. We are making the pest risk analysis available to the public for...

Numerical computation of tyre radiaion noise: a comparative study of different techniques

NARCIS (Netherlands)

Karthik, B.; Makwana, B.K.; Patel, C.; Bekke, Dirk

2012-01-01

Increasingly stringent noise regulations concerning automotive vehicles particularly in Europe are forcing Tyre manufacturers as well as the automotive manufacturers to reduce radiated noise. With the future moving towards electric/hybrid vehicles, the ever present tyre noise will become more

Waste Tyres as Heat Sink to Reduce the Driveway Surface Temperatures in Malaysia

OpenAIRE

Aniza Abdul Aziz; Sreenivasaiah Purushothama Rao; Elias Salleh

2013-01-01

The development of roads and driveways are on the rise as automobiles are now a necessity to all. This excessive development with its requirements increased the urban heat temperature and the generation of waste tyres. Waste tyre management has therefore been taken seriously by developed countries and since the European directive to ban used tyre products and whole tire disposal from landfill in 2003 and 2006 respectively, many researchers have looked for alternative ways to use the waste tyr...

Combining ESPI with laser scanning for 3D characterization of racing tyres sections

Science.gov (United States)

Pagliarulo, Vito; Farroni, Flavio; Ferraro, Pietro; Lanzotti, Antonio; Martorelli, Massimo; Memmolo, Pasquale; Speranza, Domenico; Timpone, Francesco

2018-05-01

In this work is exploited the possibility to use two optical techniques and combining their measurements for the 3D characterization of different tyres with particular attention to the tyre's section. Electronic Speckle Pattern Interferometry (ESPI) and Laser Scanner (LS) based on principle of triangulation have been employed for investigating and studying the tyre's section and 3D shape respectively. As case studies two different racing tyres, Michelin S9H and Pirelli Diablo respectively, have been considered. The investigation has been focused at the aim to evaluate and measure the section's components in order to add to the 3D model obtained by Laser Scanning accurate information about the different layers along through the tyres sections. It is important to note that the assessment about the different layers along the section is a very difficult task to obtain by visual inspection or classical microscopy and even with the LS. Here we demonstrate that the different layers can be easily highlighted and identified by mean of the ESPI.

Vehicle non-exhaust emissions from the tyre-road interface - effect of stud properties, traction sanding and resuspension

Science.gov (United States)

Kupiainen, Kaarle J.; Pirjola, Liisa

2011-08-01

In Northern cities respirable street dust emission levels (PM 10) are especially high during spring. The spring time dust has been observed to cause health effects as well as discomfort among citizens. Major sources of the dust are the abrasion products from the pavement and traction sand aggregates that are formed due to the motion of the tyre. We studied the formation of respirable abrasion particles in the tyre-road interface due to tyre studs and traction sanding by a mobile laboratory vehicle Sniffer. The measurements were preformed on a test track, where the influence of varying stud weight and stud number per tyre on PM 10 emissions was studied. Studded tyres resulted in higher emission levels than studless tyres especially with speeds 50 km h -1 and higher; however, by using light weight studs, which approximately halves the weight of studs, or by reducing the number of studs per tyre to half, the emission levels decreased by approximately half. Additionally measurements were done with and without traction sand coverage on the pavement of a public road. After traction sanding the emission levels were not affected by tyre type but by formation and suspension of traction sand related dust from the road surface. The emissions after traction sanding decreased as a function of time as passing vehicles' motion shifted the sand grains away from the areas with most tyre-road contact.

Wear and Tear of Tyres: A Stealthy Source of Microplastics in the Environment

Directory of Open Access Journals (Sweden)

Pieter Jan Kole

2017-10-01

Full Text Available Wear and tear from tyres significantly contributes to the flow of (micro-plastics into the environment. This paper compiles the fragmented knowledge on tyre wear and tear characteristics, amounts of particles emitted, pathways in the environment, and the possible effects on humans. The estimated per capita emission ranges from 0.23 to 4.7 kg/year, with a global average of 0.81 kg/year. The emissions from car tyres (100% are substantially higher than those of other sources of microplastics, e.g., airplane tyres (2%, artificial turf (12–50%, brake wear (8% and road markings (5%. Emissions and pathways depend on local factors like road type or sewage systems. The relative contribution of tyre wear and tear to the total global amount of plastics ending up in our oceans is estimated to be 5–10%. In air, 3–7% of the particulate matter (PM2.5 is estimated to consist of tyre wear and tear, indicating that it may contribute to the global health burden of air pollution which has been projected by the World Health Organization (WHO at 3 million deaths in 2012. The wear and tear also enters our food chain, but further research is needed to assess human health risks. It is concluded here that tyre wear and tear is a stealthy source of microplastics in our environment, which can only be addressed effectively if awareness increases, knowledge gaps on quantities and effects are being closed, and creative technical solutions are being sought. This requires a global effort from all stakeholders; consumers, regulators, industry and researchers alike.

Wear and Tear of Tyres: A Stealthy Source of Microplastics in the Environment

Science.gov (United States)

Kole, Pieter Jan; Löhr, Ansje J.; Van Belleghem, Frank G. A. J.; Ragas, Ad M. J.

2017-01-01

Wear and tear from tyres significantly contributes to the flow of (micro-)plastics into the environment. This paper compiles the fragmented knowledge on tyre wear and tear characteristics, amounts of particles emitted, pathways in the environment, and the possible effects on humans. The estimated per capita emission ranges from 0.23 to 4.7 kg/year, with a global average of 0.81 kg/year. The emissions from car tyres (100%) are substantially higher than those of other sources of microplastics, e.g., airplane tyres (2%), artificial turf (12–50%), brake wear (8%) and road markings (5%). Emissions and pathways depend on local factors like road type or sewage systems. The relative contribution of tyre wear and tear to the total global amount of plastics ending up in our oceans is estimated to be 5–10%. In air, 3–7% of the particulate matter (PM2.5) is estimated to consist of tyre wear and tear, indicating that it may contribute to the global health burden of air pollution which has been projected by the World Health Organization (WHO) at 3 million deaths in 2012. The wear and tear also enters our food chain, but further research is needed to assess human health risks. It is concluded here that tyre wear and tear is a stealthy source of microplastics in our environment, which can only be addressed effectively if awareness increases, knowledge gaps on quantities and effects are being closed, and creative technical solutions are being sought. This requires a global effort from all stakeholders; consumers, regulators, industry and researchers alike. PMID:29053641

ADSORPTION OF CHROMIUM (VI FROM AQUEOUS SOLUTIONS BY DIFFERENT ADMIXTURES – A BATCH EQUILIBRIUM TEST STUDY

Directory of Open Access Journals (Sweden)

K. SHIVA PRASHANTH KUMAR

2014-08-01

Full Text Available Wide variety of inorganic compounds such as nutrients and trace metals, organic chemicals, radioactive contaminants and pathogens are commonly present as contaminants in the groundwater. Migration of contaminants in soil involves important mechanisms such as molecular diffusion, dispersion under physical processes, adsorption, precipitation and oxidation - reduction under chemical processes and biodegradation under biological process. Cr (VI is a major and dangerous contaminant as per the ground water is concerned. There are numerous research work carried out with concentrated efforts by the researchers towards removal of Cr (VI contaminant from aqueous solutions. There are few studies relevant to Cr (VI removal with respect to utilization of low cost admixtures and also soil type. In the present study, different low cost admixtures like rice husk (RH, shredded tyre (ST and fly ash (FA are used to understand the performance in removal of Cr (VI from aqueous solution and also two different soil types are used along with the admixture. The results are discussed in terms of sorption capacity and performance of individual admixture and combination of admixture with soil in removal of contaminant. The fly ash, rice husk and shredded tyre admixtures are used and the results revealed that the shredded tyre showed higher performance in removal of contaminant concentration. Also, the soil which has more fine particle content (size<0.075 mm IS sieve showed reasonable reduction in concentration of contaminant at the lower levels of contaminant initial concentration. The sorption capacity results of Cr (VI contaminant, treated with various admixtures are further validated with the published work of other investigators. The shredded tyre (ST showed more adsorption capacity, i.e., 3.283 mg/g at pH of 4.8. For other admixtures, adsorption capacity value is varying in the range of 0.07 mg/g to 1.7 mg/g. Only in case of activated alumina and modified saw dust

A management system for end-of-life tyres: a Portuguese case study.

Science.gov (United States)

Ferrão, Paulo; Ribeiro, Paulo; Silva, Paulo

2008-01-01

The European Union introduced several policy instruments based in the extended producer responsibility (EPR) in order to improve the environmental performance of products and services through their life cycles. In this context, the Portuguese government decided to apply the EPR concept to tyres, and producers were obliged to constitute an end-of-life management system to promote the collection, recycling and reuse of end-of-life (EOL) tyres. This required producers, distributors, recyclers and retreaders to be identified and characterized, and local processing infrastructures to be analyzed. The information was used to design an economically optimised EOL tyre management system while promoting the activity of all EOL operators in order for the imposed collecting and recovery targets to be fulfilled. This paper discusses the interaction between the different governmental, private and academic institutions for the creation of the integrated management system for EOL tyres, the approach taken, the technical, political and legal aspects underneath them, as well as the environmental consequences induced by the creation of the management system. The results obtained during the first years of operation are reported and show an increase in the collection and recycling of EOL tyres and the consolidation of the collection and processing infrastructures.

Numerical Analysis of Partial Abrasion of the Straddle-type Monorail Vehicle running Tyre

OpenAIRE

Du, Zixue; Wen, Xiaoxia; Zhao, Dayi; Xu, Zhouzhou; Chen, Liang

2017-01-01

The finite element model of the running tyre and the pre-stressed concrete (PC) track beam are created in the study. The wheel-rail contact status under the conditions such as acceleration or braking, lateral deviation, and roll is analysed. The wear law of the running tyre under the operating condition of driving on winding roads is discussed. The results show that the running tyre will unevenly wear when driving on the winding road; the smaller curve radius and the faster speed result in he...

A model for investigating the influence of road surface texture and tyre tread pattern on rolling resistance

Science.gov (United States)

Hoever, Carsten; Kropp, Wolfgang

2015-09-01

The reduction of rolling resistance is essential for a more environmentally friendly road transportation sector. Both tyre and road design can be utilised to reduce rolling resistance. In both cases a reliable simulation tool is needed which is able to quantify the influence of design parameters on the rolling resistance of a tyre rolling on a specific road surface. In this work a previously developed tyre/road interaction model is extended to account for different tread patterns and for losses due to small-scale tread deformation. Calculated contact forces and tyre vibrations for tyre/road interaction under steady-state rolling are used to predict rolling losses in the tyre. Rolling resistance is calculated for a series of different tyre/road combinations. Results are compared with rolling resistance measurements. The agreement between simulations and measurements is generally very good. It is found that both the tyre structure and small-scale tread deformations contribute to the rolling losses. The small-scale contribution depends mainly on the road roughness profile. The mean profile depth of the road surface is identified to correlate very well with the rolling resistance. Additional calculations are performed for non-traditional rubberised road surfaces, however, with mixed results. This possibly indicates the existence of additional loss mechanisms for these surfaces.

Recommendations regarding higher axlemass limits for axles fitted with wide base tyres

CSIR Research Space (South Africa)

Roux, MP

2011-01-01

Full Text Available This paper presents the results of an investigation into possible higher axle mass limits for axles and axle units fitted with wide base tyres, i.e. tyres with nominal section widths of 385 mm, 425 mm and 445 mm, by comparing the road wear caused...

A study of the tyre/road interface under wet conditions

OpenAIRE

Mosley, J. H.

1985-01-01

This work addresses the problem of tyre tread pattern design for optimum wet grip performance. A mathematical model of tyre behaviour on wet roads has been developed. This utilizes the finite element method in the representation of tread pattern geometry. The performance of a particular tread pattern is found in terms of the fluid pressures and film thicknesses existing within the contact patch, under wet conditions. Many modern tread patterns are based on 'blocks', an...

The new tyre book. New trends - technical aspects - driving characteristics - buyer's guide; Das neue Reifenbuch. Umruestung - Reifentechnik - Fahrpraxis - Kaufberatung

Energy Technology Data Exchange (ETDEWEB)

Backfisch, K.P.; Heinz, D.S.

2000-07-01

Contents: Test methods of the tyre industry and acceptance tests; Differences between winter tyres, summer tyres and four-season tyres; Quality characteristics; Conversion to broad tyres; Tyre wall lettering; light metal wheels and tyre maintenance. There is a chapter on car driving viewed as applied physics, and the book contains hints on tyre handling as well as information on current and future trends on the tyre market. [German] Berichtet wird ueber Testverfahren der Reifenindustrie und die Verfahren zur Erstausruestungsfreigabe bei den Automobilherstellern. Das Buch informiert ueber die Unterschiede zwischen Sommer-, Winter- und Ganzjahresreifen, ueber Qualitaetsmerkmale, Umruestung auf Breitreifen oder die Seitenwandbeschriftung eines Reifens, zudem ueber Leichtmetallraeder und Reifenpflege. Autofahren ist angewandte Physik, diesem Aspekt widmet sich ein ganzes Kapitel. Der Leser erhaelt wichtige Tips zum Umgang mit Reifen sowie Informationen ueber aktuelle und kuenftige Entwicklungen auf dem Reifenmarkt. (orig.)

Properties of Pervious Concrete Containing Scrap Tyre Tubes

Directory of Open Access Journals (Sweden)

Boon Koh Heng

2017-01-01

Full Text Available There is a huge quantity of waste tyre tubes generated every year due to the increasing of motorcycle user. Therefore, recycling of the waste tyre tubes is become mandatory. The aim of this research was to study the properties of pervious concrete containing scrap tyre tube (STT rubber particles with percentages of 3%, 5% and 7% of the cement content. The properties studied are void content, compressive strength measured at 7, 14 and 28 days, flexural strength and flow rate which were determined at 28 day. The experimental results showed that, there were increased in void content and flow rate of pervious concrete containing STT. Both compressive strength and flexural strength of pervious concrete containing STT showed a lower value compared to the control mix without STT. The reductions of the mechanical strengths are likely due to the increase of void content. Overall, pervious concrete which contains 7% STT has shown an increment of mechanical strengths and flow rate compared to other STT pervious concrete. Nonetheless, the results indicate that there are potentials for use of STT in pervious concrete, especially for use in pervious concrete applications such as pavements, driveways and parking lots.

Three 3-axis accelerometers fixed inside the tyre for studying contact patch deformations in wet conditions

Science.gov (United States)

Niskanen, Arto J.; Tuononen, Ari J.

2014-05-01

The tyre-road contact area was studied visually by means of a high-speed camera and three accelerometers fixed to the inner liner of the tyre carcass. Both methods show a distorted contact area in wet conditions, but interesting differences appeared. First, the contact area in full aquaplaning seems strongly distorted on a glass plate when subjected to visual inspection, while the accelerometers indicate a more even hydrodynamic aquaplaning contact length (CL) across the tyre width. Secondly, the acceleration sensors predict the clear shortening of the CL of the tyre before the critical aquaplaning speed. It can be concluded that the visual contact area and shape are heavily dependent on the transparency of the liquid and smoothness of the glass. Meanwhile, the tyre sensors can provide a CL estimate on any road surface imaginable.

Radiation pre-vulcanization of transitional layer of all-steel load meridian tyre and performance tests of the tyre products

International Nuclear Information System (INIS)

Zhang Benshang; Zhu Chengshen; Ying Shizhou; Liu Kebo; Li Zhaopeng; Li Kunhao; Zhang Hongna; Zhao Meihong; Yang Mingcheng

2012-01-01

In this article, natural rubber is chosen as transitional layer of all-steel load meridian tyre, which is pre-vulcanized by 500 keV E-beam irradiation of up to 60 kGy. The results show that the Green strength of transitional layer increases with the dose, reaching four times at 60 kGy as much as the control (without irradiation). The viscosity of transitional layer increases rapidly below about 29 kGy, but changes little at higher doses. The final mechanical properties do not differ significantly from those of the control. However, thickness of the natural rubber transitional layer for an average single tire can be reduced by 1 mm (or 1.5 kg), without obvious adverse effect on the tyre performance. (authors)

Studies and determination of heavy metals in waste tyres and their impacts on the environment

International Nuclear Information System (INIS)

Shakya, P.R.; Shrestha, P.; Tamrakar, C.S.; Bhattarai, P.

2006-01-01

Uncontrolled burning of waste vehicle tyres causing environmental pollution has become a popular practice in developing countries like Nepal. Such activities were banned in many countries considering the environment and public health hazards but the official ban was ignored in many countries like Nepal. An experiment was conducted in a laboratory scale in an attempt to understand the potential discharge of trace metals content in Kathmandu Valley due to scrap tyre fires. For this purpose, four tyre types viz., CYCN, CSKR, BTIN and BBJP were collected representing the first two categories from passenger car and the last two from motorbike. An Atomic Absorption Spectrophotometer (AAS) was used for determination of metal concentration. Among the five heavy metals determined, Zn was detected in significantly high levels in all the tested tyre samples whereas Cd and Cr were found significantly less in many of them. The concentrations of Cd, Cr, Fe, Pb and Zn ranged from 0.020 - 27.1 micro g/g, 0.14 - 1.18 micro g/g, 17.8 - 381 micro g/g, 0.96 - 458 micro g/g and 3.95 - 8.21 micro g/g respectively. It was found that the metal concentration also varied with the tyre types and qualities. The potential discharge of the metals per representative scrap tyre mass was also estimated. Results indicate that the metal pollutants due to the uncontrolled burning of the scrap tyres could significantly contribute to deteriorate the environmental condition of the Valley. (author)

Investigation of the influence of vertical force on the contact between truck tyre and road using finite element analyses

Science.gov (United States)

Moisescu, Alexandra-Raluca; Anghelache, Gabriel

2017-10-01

In the modern context of automobile integration with the emerging technologies of the interconnected society, the interaction between tyre and road is an element of major importance for automobile safety systems such as the intelligent tyres, as well as for passenger comfort, fuel economy, environmental protection, infrastructure and vehicle durability. The tyre-road contact generates the distribution of forces exerted on each unit area in the contact patch, therefore the distribution of contact stresses on three orthogonal directions. The numerical investigation of stresses distribution in the contact patch requires the development of finite element models capable of accurately describing the interaction between tyre and rolling surface. The complex finite element model developed for the 11R22.5 truck tyre has been used for investigating the influence of vertical force on the distributions of contact stresses. In addition to these contributions, the paper presents aspects related to the simulation of truck tyre radial stiffness. The influence of tyre rolling has not been taken into consideration, as the purpose of the current research is the investigation of tyre-road contact in stationary conditions.

Tyre contact length on dry and wet road surfaces measured by three-axial accelerometer

Science.gov (United States)

Matilainen, Mika; Tuononen, Ari

2015-02-01

We determined the tyre contact length on dry and wet roads by measuring the accelerations of the inner liner with a three-axial accelerometer. The influence of the tyre pressure, driving velocity, and tread depth on the contact length was studied in both types of road surface conditions. On dry asphalt the contact length was almost constant, regardless of the driving velocity. On wet asphalt the presence of water could be detected even at low driving velocities (e.g. 20 km/h for a worn tyre) as the contact length began to decrease from that found in the dry asphalt situation. In addition to improving the performance of active safety systems and driver warning systems, the contact length information could be beneficial for classifying and studying the aquaplaning behaviour of tyres.

Carbon Fiber Reinforced Polymer with Shredded Fibers: Quasi-Isotropic Material Properties and Antenna Performance

Directory of Open Access Journals (Sweden)

Gerald Artner

2017-01-01

Full Text Available A carbon fiber reinforced polymer (CFRP laminate, with the top layer consisting of shredded fibers, is proposed and manufactured. The shredded fibers are aligned randomly on the surface to achieve a more isotropic conductivity, as is desired in antenna applications. Moreover, fiber shreds can be recycled from carbon fiber composites. Conductivity, permittivity, and permeability are obtained with the Nicolson-Ross-Weir method from material samples measured inside rectangular waveguides in the frequency range of 4 to 6 GHz. The decrease in material anisotropy results in negligible influence on antennas. This is shown by measuring the proposed CFRP as ground plane material for both a narrowband wire monopole antenna for 5.9 GHz and an ultrawideband conical monopole antenna for 1–10 GHz. For comparison, all measurements are repeated with a twill-weave CFRP.

The Scanning of Power Deformation of Tyre Surface by Tactile Piesoresistive sensors

Directory of Open Access Journals (Sweden)

Ferdinand Hurta

2004-01-01

Full Text Available Our work describes a static non-destructive method of measuring the contact pressures of tyres. The distribution of contact pressures during the contact of the tyre with a solid base represents one of the indicators we use. In this process, it is convenient to use matrix tactile sensors based on piezoresistive method of data collection.

Design and testing of an innovative measurement device for tyre-road contact forces

Science.gov (United States)

Cheli, F.; Braghin, F.; Brusarosco, M.; Mancosu, F.; Sabbioni, E.

2011-08-01

The measurement of tyre-road contact forces is the first step towards the development of new control systems for improving vehicle safety and performances. Tyre-road contact forces measurement systems are very expensive and significantly modify the unsprung masses of the vehicle as well as the rotational inertia of the tyres. Thus, vehicle dynamics results are significantly affected. As a consequence, the measured contact forces do not correspond to the contact forces under real working conditions. A new low-cost tyre-road contact forces measurement system is proposed in this paper that can be applied to passenger cars. Its working principle is based on the measurement of three deformations of the wheel rim through strain gauges. The tyre-rim assembly is thus turned into a sensor for tyre-road contact forces. The influence of the strain gauges position onto the measurement results has been assessed through finite element simulations and experimental tests. It has been proven that, for a large variety of rims, the strain gauge position that leads to high signal-to-noise ratios is almost the same. A dynamic calibration procedure has been developed in order to allow the reconstruction of contact force and torque components once per wheel turn. The capability of the developed device to correctly estimate tyre-road contact forces has been assessed, in a first stage, through indoor laboratory experimental test on an MTS Flat-Trac ® testing machine. Results show that the implemented measuring system allows to reconstruct contact forces once per wheel turn with a precision that is comparable to that of existing high-cost measurement systems. Subsequently, outdoor tests with a vehicle having all four wheels equipped with the developed measuring device have also been performed. Reliability of the measurements provided by the developed sensor has been assessed by comparing the global measured longitudinal/lateral forces and the product of the measured longitudinal

Production of activated carbons from waste tyres for low temperature NOx control.

Science.gov (United States)

Al-Rahbi, Amal S; Williams, Paul T

2016-03-01

Waste tyres were pyrolysed in a bench scale reactor and the product chars were chemically activated with alkali chemical agents, KOH, K2CO3, NaOH and Na2CO3 to produce waste tyre derived activated carbons. The activated carbon products were then examined in terms of their ability to adsorb NOx (NO) at low temperature (25°C) from a simulated industrial process flue gas. This study investigates the influence of surface area and porosity of the carbons produced with the different alkali chemical activating agents on NO capture from the simulated flue gas. The influence of varying the chemical activation conditions on the porous texture and corresponding NO removal from the flue gas was studied. The activated carbon sorbents were characterized in relation to BET surface area, micropore and mesopore volumes and chemical composition. The highest NO removal efficiency for the waste tyre derived activated carbons was ∼75% which was obtained with the adsorbent treated with KOH which correlated with both the highest BET surface area and largest micropore volume. In contrast, the waste tyre derived activated carbons prepared using K2CO3, NaOH and Na2CO3 alkali activating agents appeared to have little influence on NO removal from the flue gases. The results suggest problematic waste tyres, have the potential to be converted to activated carbons with NOx removal efficiency comparable with conventionally produced carbons. Copyright © 2016 Elsevier Ltd. All rights reserved.

A 3D model for rubber tyres contact, based on Kalker's methods through the STRIPES model

Science.gov (United States)

Chollet, Hugues

2012-01-01

A project on the pavement-rutting evolution under the effect of a tram on tyre, led the author to make a link between road and railway approaches to the problem of rolling contact. A simplified model is proposed with a fine description of the contact patch between a tyre and the road, and a more realistic pressure and shear stresses distribution than that available from basic models previously available. Experimental measurements are used to identify some characteristics of the force description, while the geometric shape of the tyre-road section are used, like in the traditional rail-wheel contact models, to build the 3D model. The last part validates a plausible contact pressure shape from self-aligning torque measurements and from Kalker's contact stresses gradient applied to the real tyre used in the project. The final result is a brush model extended from the wheel-rail STRIPES one, applicable to dynamics or contact studies of real tyres, with a physical coupling between longitudinal, lateral and spin effects, and a relatively fine description of the contact stresses along each strip of each tyre of the vehicle on an uneven road.

The effect of shredding and test apparatus size on compressibility and strength parameters of degraded municipal solid waste.

Science.gov (United States)

Hossain, M S; Gabr, M A; Asce, F

2009-09-01

In many situations, MSW components are processed and shredded before use in laboratory experiments using conventional soil testing apparatus. However, shredding MSW material may affect the target property to be measured. The objective of this study is to contribute to the understanding of the effect of shredding of MSW on the measured compressibility and strength properties. It is hypothesized that measured properties can be correlated to an R-value, the ratio of waste particle size to apparatus size. Results from oedometer tests, conducted on 63.5 mm, 100 mm, 200 mm diameter apparatus, indicated the dependency of the compressibility parameters on R-value. The compressibility parameters are similar for the same R-value even though the apparatus size varies. The results using same apparatus size with variable R-values indicated that shredding of MSW mainly affects initial compression. Creep and biological strain rate of the tested MSW are not significantly affected by R-value. The shear strength is affected by shredding as the light-weight reinforcing materials are shredded into smaller pieces during specimen preparation. For example, the measured friction angles are 32 degrees and 27 degrees for maximum particle sizes of 50 mm and 25 mm, respectively. The larger MSW components in the specimen provide better reinforcing contribution. This conclusion is however dependent on comparing specimen at the same level of degradation since shear strength is also a function of extent of degradation.

Sorption Potentials of Waste Tyre for Some Heavy Metals (Pb Cd in Aqueous Solution

Directory of Open Access Journals (Sweden)

Austin Kanayo ASIAGWU

2009-07-01

Full Text Available An investigation into the adsorption potential of activated and inactivated waste tyre powders for some heavy metals (Pb2+ and Cd2+ in their aqueous solution has been studied. The result indicated that inactivated waste tyre is a good non-conventional adsorbent for the removal of Cd from aqueous solution. A total of 93.3% of Cadmium contents was removed. The inactivated waste type proved a good adsorbent for the removal of Pb2+ 5g of 500mm activated tyre removed over 86.66% of Pb2+ from solution.

Thermogravimetric characteristics and kinetics of scrap tyre and Juglans regia shell co-pyrolysis.

Science.gov (United States)

Uzun, B B; Yaman, E

2014-10-01

The degradation kinetics of Juglans regia shell, scrap tyre and their blends were investigated using a thermogravimetric analysis method. Experiments were performed under dynamic conditions and a nitrogen atmosphere in the range 293 to 973 K at different heating rates. During pyrolysis of J. regia shell three mass loss zones were specified as removal of water, decomposition of hemicelluloses and cellulose, and decomposition of lignin. The degradation curves of scrap tyre showed merely one stage which was due to decomposition of styrene butadiene rubber. The kinetic parameters were calculated using both Arrhenius and Coats-Redfern methods. By adopting the Arrhenius method, the average value of activation energies of J. regia shell, scrap tyre and their 1 : 1 blends were found to be 69.22, 71.48 and 47.03 kJ mol(-1), respectively. Additionally, by using the Coats-Redfern method, the average value of activation energies of J. regia shell, scrap tyre and their 1 : 1 blend were determined as 99.85, 78.72 and 63.81 kJ mol(-1), respectively. The addition of J. regia shell to scrap tyre caused a reduction in the activation energies. The difference of weight loss was measured to examine interactions between raw materials. The maximum difference between experimental and theoretical mass loss was 5% at about 648 K with a heating rate of 20 K min(-1). These results indicated a significant synergistic effect was available during co-pyrolysis of J. regia shell and scrap tyre in the high temperature region. © The Author(s) 2014.

Experimental study of tyre/road contact forces in rolling conditions for noise prediction

Science.gov (United States)

Cesbron, Julien; Anfosso-Lédée, Fabienne; Duhamel, Denis; Ping Yin, Hai; Le Houédec, Donatien

2009-02-01

This paper deals with the experimental study of dynamical tyre/road contact for noise prediction. In situ measurements of contact forces and close proximity noise levels were carried out for a slick tyre rolling on six different road surfaces between 30 and 50 km/h. Additional texture profiles of the tested surfaces were taken on the wheel track. Normal contact stresses were measured at a sampling frequency of 10752 Hz using a line of pressure sensitive cells placed both along and perpendicular to the rolling direction. The contact areas obtained during rolling were smaller than in static conditions. This is mainly explained by the dynamical properties of tyre compounds, like the viscoelastic behaviour of the rubber. Additionally the root-mean-square of the resultant contact forces at various speeds was in the same order for a given road surface, while their spectra were quite different. This is certainly due to a spectral influence of bending waves propagating in the tyre during rolling, especially when the wavelength is small in comparison with the size of the contact patch. Finally, the levels of contact forces and close proximity noise measured at 30 km/h were correlated. Additional correlations with texture levels were performed. The results show that the macro-texture generates contact forces linearly around 800 Hz and consequently noise levels between 500 and 1000 Hz via the vibrations transmitted to the tyre.

Characterization of the liquid products obtained in tyre pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Laresgoiti, M.F.; Caballero, B.M.; De Marco, I.; Torres, A.; Cabrero, M.A.; Chomon, M.J. [Escuela Superior de Ingenieros de Bilbao, Alda. Urquijo s/n, Bilbao 48013 (Spain)

2004-06-01

Cross-section samples (2-3cm wide), representative of a whole car tyre, have been pyrolysed under nitrogen in a 3.5dm{sup 3} autoclave at 300, 400, 500, 600 and 700C. Over 500C there is no effect of temperature on gases and liquids yields ({approx}17 and 38%, respectively). Tyre pyrolysis liquids have been characterized, including elemental analysis, gross calorific value (GCV), gas chromatography/mass spectroscopy (GC/MS) and distillation. Tyre derived liquids are a complex mixture of C{sub 6}-C{sub 24} organic compounds, with a lot of aromatics (53.4-74.8%), some nitrogenated (2.47-3.5%) and some oxygenated compounds (2.29-4.85%). They have GCV (42MJkg{sup -1}) even higher than those specified for commercial heating oils, but sulphur contents (1-1.4%) near or slightly over the law limit value. Significant quantities of valuable light hydrocarbons such as benzene, toluene, xylene, limonene, etc. were obtained. The concentration of these compounds increase with temperature up to 500C and then decrease. There are an important proportion of polycyclic aromatics such as naphthalenes, phenanthrenes, fluorenes, diphenlys, etc.; their concentration as well as that of total aromatics increases significantly with temperature. Distillation data of the 500C oils showed that {approx}20% have the boiling range of light naphtha (<160C), {approx}10% of heavy naphtha (160-204C) and {approx}35% of middle distillate (204-350C). As far as distillation data are concerned, the tyre oil fractions with the same boiling range as commercial automotive diesel oils and heating diesel oils fulfil the present specifications of such commercial products.

Immobilisation of shredded soft waste in cement monolith

International Nuclear Information System (INIS)

Brown, D.J.; Dalton, M.J.; Smith, D.L.

1983-04-01

A grouting process for the immobilisation of shredded contaminated laboratory waste in a cement monolith is being developed at the Atomic Energy Establishment Winfrith. The objective is to produce a 'monolithic' type package which is acceptable both for sea and land disposal. The work carried out on this project in the period April 1982 - March 1983 is summarised in this report. (author)

Determination of rolling resistance coefficient based on normal tyre stiffness

Science.gov (United States)

Rykov, S. P.; Tarasuyk, V. N.; Koval, V. S.; Ovchinnikova, N. I.; Fedotov, A. I.; Fedotov, K. V.

2018-03-01

The purpose of the article is to develop analytical dependence of wheel rolling resistance coefficient based on the mathematical description of normal tyre stiffness. The article uses the methods of non-holonomic mechanics and plane section methods. The article shows that the abscissa of gravity center of tyre stiffness expansion by the length of the contact area is the shift of normal road response. It can be used for determining rolling resistance coefficient. When determining rolling resistance coefficient using ellipsis and power function equations, one can reduce labor costs for testing and increase assessment accuracy.

Identification of the characteristics of motorcycle and scooter tyres in the presence of large variations in inflation pressure

Science.gov (United States)

Cossalter, V.; Doria, A.; Giolo, E.; Taraborrelli, L.; Massaro, M.

2014-10-01

Stability and safety of road vehicles are largely affected by tyre properties. Single-track vehicles are characterised by weakly damped modes of vibration (weave and wobble) and therefore this phenomenon is even more important. This article focuses on the study of both steady-state and transient properties of motorcycle and scooter tyres in the presence of very low and very high inflation pressures. The steady-state properties are defined as lateral forces (side-slip and camber forces) and yaw torques (self-aligning and twisting). The transient properties are described in terms of relaxation length, which represents the distance needed to reach a certain percentage of the steady-state value of the tyre force. Experimental tests are carried out on a specific rotating disk machine. Three sets of tyres are analysed. Steady-state properties are measured by increasing step by step the values of camber and side-slip angles. Transient properties are studied carrying out tests with harmonic side-slip excitation and measuring the phase lag between the excitation (input) and the tyre force (output). Experimental results show important variations in tyre properties with inflation pressure with general trends of all the tested tyres and particular features related to the tyre's geometry. After the analysis and discussion of experimental results, the measured data are fitted by means of a specific version of the Magic Formula. The dependence of the Magic Formula's coefficients on inflation pressure is analysed and interpolation curves are given.

Modeling road-tyre noise

OpenAIRE

Martins, Mário M. Abreu; Santos, Luís Picado; Freitas, Elisabete F.

2008-01-01

The growing awareness by the broader public of the consequences to health and wellbeing due to road noise has led to a growing number of legal requirements being produced to deal with this matter, both in the design of new or assessment of existing infrastructure. In this article the purpose is to make an up-to-date review of existing studies being carried out to deliver models for predicting noise produced from tyre-road contact, taking account of different methodological appr...

On the influence of tyre and structural properties on the stability of bicycles

Science.gov (United States)

Doria, Alberto; Roa Melo, Sergio Daniel

2018-06-01

In recent years the Whipple Carvallo Bicycle Model has been extended to analyse high speed stability of bicycles. Various researchers have developed models taking into account the effects of front frame compliance and tyre properties, nonetheless, a systematic analysis has not been yet carried out. This paper aims at analysing parametrically the influence of front frame compliance and tyre properties on the open loop stability of bicycles. Some indexes based on the eigenvalues of the dynamic system are defined to evaluate quantitatively bicycle stability. The parametric analysis is carried out with a factorial design approach to determine the most influential parameters. A commuting and a racing bicycle are considered and numerical results show different effects of the various parameters on each bicycle. In the commuting bicycle, the tyre properties have greater influence than front frame compliance, and the weave mode has the main effect on stability. Conversely, in the racing bicycle, the front frame compliance parameters have greater influence than tyre properties, and the wobble mode has the main effect on stability.

Viscosity and Plasticity of Latvian Illite Clays

OpenAIRE

Jurgelāne, I; Vecstaudža, J; Stepanova, V; Mālers, J; Bērziņa-Cimdiņa, L

2012-01-01

Due to viscosity and plasticity, clays and clay minerals are used in civil engineering, pottery and also in cosmetics and medicine as thickening agents and emulsion and suspension stabilizers. The rheological properties of clay suspensions are complex. Mostly it is an interaction between mineral composition, clay particle size and pH value and also depends on clay minerals. Clay-water suspension is non-Newtonian fluid showing thixotropic and pseudoplastic properties. Results showed that plast...

On the Horn Effect of a Tyre/road Interface, Part i: Experiment and Computation

Science.gov (United States)

Graf, R. A. G.; Kuo, C.-Y.; Dowling, A. P.; Graham, W. R.

2002-09-01

Near the tyre/road contact area, the road surface and the tyre belt form a horn-like geometry, which provides a significant amplification mechanism for sound sources. Measurements have been carried out on a stationary tyre placed on a plane surface in an otherwise anechoic chamber. Following the reciprocal theorem a microphone was placed in the road surface near the contact patch and a white noise source was used in the far field. The amplification by the horn effect can then be determined as a function of frequency for an array of microphone positions relative to the contact patch and the centre of the tyre. These experimental measurements show that the horn effect is responsible for about 10-20dB increase in noise level. The amplification function shows a distinct interference pattern for higher frequencies and is independent of the longitudinal source position for low frequencies and source positions close to the contact patch. Numerical calculations using the indirect boundary element method have been carried out. These show excellent agreement with the measurements in the frequency regime of the BEM, i.e., up to 2500 Hz. The dependence of the horn effect on primary geometrical parameters such as the effect of the radius of curvature of the shoulders, the load and the width of the tyre has been investigated experimentally and numerically. The broad features of the horn effect are given by the cylindrical geometry of the tyre. The rounded edges of the tyre tend to increase the levels of the minima and shift them to higher frequencies, while slightly decreasing the levels of the maxima. Shape variations due to load can be accounted for by correcting the source distance to the edge of the formed contact patch. The amplification at low frequencies increases with width, the results collapsing onto a single curve as a function of the dimensionless width ω / λ.

Decontamination and survival of Enterobacteriaceae on shredded iceberg lettuce during storage.

Science.gov (United States)

Osaili, Tareq M; Alaboudi, Akram R; Al-Quran, Heba N; Al-Nabulsi, Anas A

2018-08-01

Enterobacteriaceae family can contaminate fresh produce at any stage of production either at pre-harvest or post-harvest stages. The objectives of the current study were to i) identify Enterobacteriaceae species on iceberg lettuce, ii) compare the decontamination efficiency of water, sodium hypochlorite (free chlorine 200 ppm), peroxyacetic acid (PA 80 ppm; Kenocid 2100 ® ) or their combinations and ionizing radiation against Enterobacteriaceae on shredded iceberg lettuce and iii) determine the survival of Enterobacteriaceae post-treatment storage of shredded iceberg lettuce at 4, 10 and 25 °C, for up to 7 days. Klebsiella pneumonia spp. pneumonia, Enterobacter cloacae, Klebsiella oxytoca, Pantoea spp., Leclercia adecarboxylata and Kluyvera ascorbate were identified on iceberg lettuce. No significant difference (P≥ 0.05) among Enterobacteriaceae survival after washing with water or sanitizing with sodium hypochlorite or Kenocid 2100 ® (reduction ≤ 0.6 log CFU/g) were found. Combined sanitizer treatments were more effective against Enterobacteriaceae than single washing/sanitizing treatments. Sanitization of iceberg lettuce with combined washing/sanitizing treatments reduced Enterobacteriaceae by 0.85-2.24 CFU/g. Post-treatment growth of Enterobacteriaceae during storage on samples sanitized with sodium hypochlorite and Kenocid 2100 ® was more than on samples washed with water. The D 10 -value of Enterobacteriaceae on shredded iceberg lettuce was 0.21 KGy. The reduction of Enterobacteriaceae populations on iceberg after gamma radiation (0.6 KGy) was 3 log CFU/g, however, Enterobacteriaceae counts increased post-irradiation storage by 4-5 log CFU/g. Therefore, washing shredded iceberg lettuce with combined sanitizing treatment (sodium hypochlorite/sodium hypochlorite, sodium hypochlorite/Kenocid 2100 ® , or Kenocid 2100 ® /Kenocid 2100 ® ) for total time of 6 min or exposing it to gamma irradiation (0.6 KGy) can decrease the risk of

Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material

Energy Technology Data Exchange (ETDEWEB)

Gustafsson, Mats [Swedish National Road and Transport Research Institute (VTI), SE-581 95 Linkoeping (Sweden)], E-mail: mats.gustafsson@vti.se; Blomqvist, Goeran [Swedish National Road and Transport Research Institute (VTI), SE-581 95 Linkoeping (Sweden); Gudmundsson, Anders; Dahl, Andreas [Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden); Swietlicki, Erik [Division of Nuclear Physics, Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden); Bohgard, Mats [Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden); Lindbom, John; Ljungman, Anders [Faculty of Health Sciences, Department of Molecular and Clinical Medicine, Division of Occupational and Environmental Medicine, SE-581 85 Linkoeping (Sweden)

2008-04-15

In regions where studded tyres and traction material are used during winter, e.g. the Nordic countries, northern part of USA, Canada, and Japan, mechanically generated particles from traffic are the main reason for high particle mass concentrations in busy street and road environments. In many Nordic municipalities the European environmental quality standard for inhalable particles (PM{sub 10}) is exceeded due to these particles. In this study, particles from the wear of studded and studless friction tyres on two pavements and traction sanding were generated using a road simulator. The particles were characterized using particle sizers, Particle Induced X-Ray Emission Analysis and electron microscopy. Cell studies were conducted on particles sampled from the tests with studded tyres and compared with street environment, diesel exhaust and subway PM{sub 10}, respectively. The results show that in the road simulator, where resuspension is minimized, studded tyres produce tens of times more particles than friction tyres. Chemical analysis of the sampled particles shows that the generated wear particles consist almost entirely of minerals from the pavement stone material, but also that Sulfur is enriched for the submicron particles and that Zink is enriched for friction tyres for all particles sizes. The chemical data can be used for source identification and apportionment in urban aerosol studies. A mode of ultra-fine particles was also present and is hypothesised to originate in the tyres. Further, traction material properties affect PM{sub 10} emission. The inflammatory potential of the particles from wear of pavements seems to depend on type of pavement and can be at least as potent as diesel exhaust particles. The results imply that there is a need and a good potential to reduce particle emission from pavement wear and winter time road and street operation by adjusting both studded tyre use as well as pavement and traction material properties.

Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material

International Nuclear Information System (INIS)

Gustafsson, Mats; Blomqvist, Goeran; Gudmundsson, Anders; Dahl, Andreas; Swietlicki, Erik; Bohgard, Mats; Lindbom, John; Ljungman, Anders

2008-01-01

In regions where studded tyres and traction material are used during winter, e.g. the Nordic countries, northern part of USA, Canada, and Japan, mechanically generated particles from traffic are the main reason for high particle mass concentrations in busy street and road environments. In many Nordic municipalities the European environmental quality standard for inhalable particles (PM 10 ) is exceeded due to these particles. In this study, particles from the wear of studded and studless friction tyres on two pavements and traction sanding were generated using a road simulator. The particles were characterized using particle sizers, Particle Induced X-Ray Emission Analysis and electron microscopy. Cell studies were conducted on particles sampled from the tests with studded tyres and compared with street environment, diesel exhaust and subway PM 10 , respectively. The results show that in the road simulator, where resuspension is minimized, studded tyres produce tens of times more particles than friction tyres. Chemical analysis of the sampled particles shows that the generated wear particles consist almost entirely of minerals from the pavement stone material, but also that Sulfur is enriched for the submicron particles and that Zink is enriched for friction tyres for all particles sizes. The chemical data can be used for source identification and apportionment in urban aerosol studies. A mode of ultra-fine particles was also present and is hypothesised to originate in the tyres. Further, traction material properties affect PM 10 emission. The inflammatory potential of the particles from wear of pavements seems to depend on type of pavement and can be at least as potent as diesel exhaust particles. The results imply that there is a need and a good potential to reduce particle emission from pavement wear and winter time road and street operation by adjusting both studded tyre use as well as pavement and traction material properties

Comparison of contact stresses of the test tyres used by the one third scale model mobile load simulator (MMLS3) and the full-scale test tyres of the Heavy Vehicle Simulator (HVS) - a summary

CSIR Research Space (South Africa)

De Beer, Morris

2007-07-01

Full Text Available This paper summarises the results of a study in which the maximum vertical contact stressess of the one third scale test tyres of the Model Mobile Load Simulator (MMLS3) were compared with those measured for three types of full-scale test tyres...

Mechanical interaction between swelling compacted clay and fractured rock, and the leaching of clay colloids

NARCIS (Netherlands)

Grindrod, P.; Peletier, M.A.; Takase, H.

1999-01-01

We consider the interaction between a saturated clay buffer layer and a fractured crystalline rock engineered disturbed zone. Once saturated, the clay extrudes into the available rock fractures, behaving as a compressible non-Newtonian fluid. We discuss the modelling implications of published

Experimental and numerical analysis of the influence of tyres' properties on the straight running stability of a sport-touring motorcycle

Science.gov (United States)

Cossalter, Vittore; Doria, Alberto; Formentini, Matteo; Peretto, Martino

2012-03-01

The behaviour of a motorcycle on the road is largely governed by tyre properties. This paper presents experimental and numerical analyses dealing with the influence of tyre properties on the stability of weave and wobble in straight running. The final goal is to find optimal sets of tyre properties that improve the stability of a motorcycle. The investigation is based on road tests carried out on a sport-touring motorcycle equipped with sensors. Three sets of tyres are tested at different speeds in the presence of weave and wobble. The analysis of telemetry data highlights significant differences in the trends of frequency and damping of weave and wobble against speed. The experimental analysis is integrated by a parametric numerical analysis. Tyre properties are varied according to the design of experiments method, in order to highlight the single effects on stability of lateral and cornering coefficient of front and rear tyres.

Allyl isothiocyanate enhances shelf life of minimally processed shredded cabbage.

Science.gov (United States)

Banerjee, Aparajita; Penna, Suprasanna; Variyar, Prasad S

2015-09-15

The effect of allyl isothiocyanate (AITC), in combination with low temperature (10°C) storage on post harvest quality of minimally processed shredded cabbage was investigated. An optimum concentration of 0.05μL/mL AITC was found to be effective in maintaining the microbial and sensory quality of the product for a period of 12days. Inhibition of browning was shown to result from a down-regulation (1.4-fold) of phenylalanine ammonia lyase (PAL) gene expression and a consequent decrease in PAL enzyme activity and o-quinone content. In the untreated control samples, PAL activity increased following up-regulation in PAL gene expression that could be linearly correlated with enhanced o-quinone formation and browning. The efficacy of AITC in extending the shelf life of minimally processed shredded cabbage and its role in down-regulation of PAL gene expression resulting in browning inhibition in the product is reported here for the first time. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Serial Food Poisoning Outbreaks Caused by Norovirus-Contaminated Shredded Dried Laver Seaweed Provided at School Lunch, Tokyo, 2017].

Science.gov (United States)

Somura, Yoshiko; Kimoto, Kana; Oda, Mayuko; Okutsu, Yuta; Kato, Rei; Suzuki, Yasunori; Siki, Dai; Hirai, Akihiko; Akiba, Tetsuya; Shinkai, Takayuki; Sadamasu, Kenji

2017-01-01

In February 2017, four food poisoning outbreaks occurred in Tokyo, involving ten schools. Shredded dried laver seaweed processed by a single food manufacturer in December 2016 was provided in common for the school meals that caused all four outbreaks. Of 4,209 persons exposed, 1,193 (28.3%) had symptoms of gastroenteritis. Norovirus (NoV) GII was detected in 207 (78.1%) of 265 cases by real-time RT-PCR. Thirty-one shredded dried laver seaweed samples were examined and seven (22.6%) of them were positive for NoV GII. PCR fragments of NoV ORF1/2 junction region (302 bp) from seven shredded dried laver seaweed samples and 20 clinical samples derived from the four outbreaks were sequenced. All of them displayed complete homology, and the genotype was classified as GII.17. A nearly full-length sequence (7,420 bp) of NoV RNA derived from a case was obtained by next-generation sequencer analysis and phylogenetic analysis indicated that this strain belongs to the same cluster as Hu/GII/JP/2015/GII.P17_GII.17/Kawasaki308. Thus, our investigation elucidated that the causative agent of these four serial food poisoning outbreaks was NoV GII.17 and the infectious source was a single batch of shredded dried laver seaweed. The water activity of the shredded dried laver seaweed was found to be 0.119 to 0.129. It was epidemiologically clarified that NoV does not lose infectivity for about two months even in the dry state. We conclude that a large diffuse outbreak of food poisoning caused by NoV GII.17 contamination of shredded dried laver seaweed had occurred in Tokyo. Our elucidation of the causative agent indicated that the food poisoning outbreaks in multiple areas of Japan, including Tokyo, during January to February 2017 were caused by the same contaminated food.

The HADES project - ten years of civil engineering practice in a plastic clay formation

International Nuclear Information System (INIS)

De Bruyn, D.J.; Neerdael, B.A.

1991-01-01

Various civil engineering works and underground experiments have been performed during the last ten years in Belgium to assess the technical feasibility of building a repository for high level waste (HLW) disposal in a plastic clay formation; they lead to the conclusion that the construction of tunnels for this purpose may now be considered as technically and economically feasible. (author)

The influence of tyre transient side force properties on vehicle lateral acceleration for a time-varying vertical force

Science.gov (United States)

Takahashi, Toshimichi

2018-05-01

The tyre model which formerly developed by the author et al. and describes the tyre transient responses of side force and aligning moment under the time-varying vertical force was implemented to the vehicle dynamics simulation software and the influence of tyre side force transient property on the vehicle behaviour was investigated. The vehicle responses with/without tyre transient property on sinusoidally undulated road surfaces were simulated and compared. It was found that the average lateral acceleration of the vehicle at the sinusoidal steering wheel angle input decreases on the undulated road of long wavelength (3 m) for both cases, but when the wavelength becomes shorter (1 m), the average lateral acceleration increases only in the case that the transient property is considered. The cause of those changes is explained by using the tyre-related variables. Also the steady-state turning behaviour of the vehicle on undulated roads are shown and discussed.

Clay nanoparticles for regenerative medicine and biomaterial design: A review of clay bioactivity.

Science.gov (United States)

Mousa, Mohamed; Evans, Nicholas D; Oreffo, Richard O C; Dawson, Jonathan I

2018-03-01

Clay nanoparticles, composites and hydrogels are emerging as a new class of biomaterial with exciting potential for tissue engineering and regenerative medicine applications. Clay particles have been extensively explored in polymeric nanocomposites for self-assembly and enhanced mechanical properties as well as for their potential as drug delivery modifiers. In recent years, a cluster of studies have explored cellular interactions with clay nanoparticles alone or in combination with polymeric matrices. These pioneering studies have suggested new and unforeseen utility for certain clays as bioactive additives able to enhance cellular functions including adhesion, proliferation and differentiation, most notably for osteogenesis. This review examines the recent literature describing the potential effects of clay-based nanomaterials on cell function and examines the potential role of key clay physicochemical properties in influencing such interactions and their exciting possibilities for regenerative medicine. Copyright © 2018 Elsevier Ltd. All rights reserved.

Simulation of the long term alteration of clay minerals in engineered bentonite barriers: nucleation and growth of secondary clay particles

International Nuclear Information System (INIS)

Fritz, B.; Clement, A.; Zwingmann, H.; Noguera, C.

2010-01-01

Document available in extended abstract form only. The long term stability of clay rich rocks used as barriers to the migration of radionuclides in the environment of nuclear wastes has been intensively studied, looking at the geochemical interactions between clay minerals and aqueous solutions. These studies combine experimental approaches for the short term and numerical modellings for the long term extrapolations, in the frame of the research supported by ANDRA in the French design for High Level Waste (HLW) repository. The main objective of the geochemical numerical tools devoted to clay-solutions interaction processes was to predict the feed-back effects of mineralogical and chemical transformations of clay mineral, in repository conditions as defined by Andra, on their physical and transport properties (porosity, molecular diffusion, permeability). The 1D transport-reaction coupled simulation was done using the code KIRMAT, at 100 deg. C for 100000 years. The fluid considered is that of the Callovo-Oxfordian geological formation (COX) and assumed to diffuse into the clay barrier from one side. On the other side, ferrous iron, is provided by the steel overpack corrosion. Under these conditions, montmorillonite of the clay barrier is only partially transformed into illite, chlorite, and saponite. The simulation shows that only outer parts of the clay barrier is significantly modified, mainly at the interface with the geological environment. These modifications correspond to a closure of the porosity, followed by a decrease of mass transport by molecular diffusion. Near the COX, the swelling pressure of the clays from the barrier is predicted to decrease, but in its major part, the engineered barrier seems to keep its initial physical properties (porosity, molecular diffusion, permeability, swelling pressure). In this modelling approach, the very important role of secondary clay minerals has to be taken into account with relevant kinetic rate laws; particularly

Stress-In-Motion (SIM) system for capturing tri-axial tyre-road interaction in the contact patch

CSIR Research Space (South Africa)

De Beer, Morris

2013-08-01

Full Text Available elements has a 9.7 mm diameter circular contact surface area ( 73.9 mm2) and is dimensionally optimised, allowing measurements in various tyre rolling conditions on a textured measuring surface. The textured surface induces some pre-conditioning of tyre...

Dynamic interaction of brakes, tyres and road surface; Dynamische Interaktion Bremse - Reifen - Strasse

Energy Technology Data Exchange (ETDEWEB)

Huinink, H.; Schroeder, C.

1999-12-01

Rubber friction of rough surfaces is characterised by the molecular physics of the highly dynamic interaction between a polymer network and the road on nano- micrao- and macroscale length. The problems of power transmission of ALS-controlled tyres at quasi-stationary conditions (interaction tyres/braking system) are described by the grip/slip characteristics defined for the area of tyre contact, which in terms forms the basis for the interaction between material and road surface (according to Persson 1997) under the respective technical conditions of the vehicle. ALS-braking with time-dependent brake torque is a technically highly dynamic system state within the interaction of material, tyres, vehicle and road surface. New systems based on sensors such as the side-torsion-sensor made by Continental AG improve safety, comfort and economy by combining this feature with a vehicle management system which uses tyre forces and -deformation as input parameters. [Deutsch] Die Gummireibung auf rauhen Oberflaechen ist durch eine molekulare Physik der hochdynamischen Interaktion Polymernetzwerk / Fahrbahn auf nano-, mikro- und makroskaligen Laengen gekennzeichnet. Die Problematik der Kraftuebertragung bei ABS-geregelten Reifen unter quasistationaeren Bedingungen (Interaktion Reifen - Bremssystem) wird durch die in der Bodenaufstandsflaeche ortsaufgeloesten Kraftschluss - Schlupf - Kennlinien erfasst, deren Basis die Interaktion Material / Fahrbahn nach Persson (1997) unter den gegebenen technischen Bedingungen am Fahrzeug darstellt. Der ABS-Bremsvorgang bei zeitabhaengigem Bremsmoment ist ein technisch hochdynamischer Systemzustand im Wechselspiel Material - Reifen - Fahrzeug-Fahrbahn. Auf der Sensorik basierende dynamische Systemerweiterungen, wie z.B. durch den Seitenwand-Torsions-Sensor der Continental AG, verbessern Fahrsicherheit, Komfort und Wirtschaftlichkeit durch die Kombination mit einem Fahrzeugmanagementsystem, das die Reifenkraefte und -verformungen als

The influence of tyre contact patch and on the stopping distance of automotive vehicles

Science.gov (United States)

Selig, M.; Ball, A.; Ash, J.; Schmidt, K.

2012-05-01

This contribution presents the experimental tests results about the influence of the tyre contact patch on the stopping distance of automotive vehicles. The objective of the performed tests is the evaluation of the effect of tyre inflation pressure, hence the resulting tyre contact patch on the braking system and the brake distance. The conditions of the experiment are a dry and level road surface without steering inputs. To record scientific results, a brake robot system is used. The benefit of a robotic system is the elimination of the interfering variable driver, who is not able to apply the brake system at the same time with the same force. State-of-the-art data acquisition tools are used to log the data.

The influence of tyre contact patch and on the stopping distance of automotive vehicles

International Nuclear Information System (INIS)

Selig, M; Ball, A; Ash, J; Schmidt, K

2012-01-01

This contribution presents the experimental tests results about the influence of the tyre contact patch on the stopping distance of automotive vehicles. The objective of the performed tests is the evaluation of the effect of tyre inflation pressure, hence the resulting tyre contact patch on the braking system and the brake distance. The conditions of the experiment are a dry and level road surface without steering inputs. To record scientific results, a brake robot system is used. The benefit of a robotic system is the elimination of the interfering variable driver, who is not able to apply the brake system at the same time with the same force. State-of-the-art data acquisition tools are used to log the data.

Growth of Listeria spp. in shredded cabbage is enhanced by a mild heat treatment.

Science.gov (United States)

Ells, Timothy C; Truelstrup Hansen, Lisbeth

2010-03-01

Mild thermal processing can enhance the shelf life of cut fruits and vegetables by delaying the onset of spoilage and preserving the organoleptic properties of shredded cabbage. However, food safety issues related to this process have not been fully investigated. Therefore, the survival and growth of Listeria spp. on cabbage treated in this manner was examined. Experimentally, 24 strains of Listeria spp. (including L. monocytogenes) were inoculated onto cut and intact cabbage tissues and stored at 5 degrees C. All strains on intact tissues exhibited a moderate decline in numbers (up to 1.0 log CFU/cm(2)) over the 28-day storage period. Conversely, cut tissue supported growth of most strains during the first 7 to 14 days of incubation with maximum increases of 1.2 log CFU/cm(2). Subsequently, the survival or growth on heat-treated (50 degrees C for 3 min) and untreated shredded cabbage of four L. monocytogenes and four nonpathogenic Listeria spp. strains were compared during storage for 21 days at 5 degrees C. Growth on untreated shred for all strains was similar to the results observed on cut tissue with a maximum increase of approximately 1.0 log CFU/g. However, in the heat-treated cabbage shred all strains displayed a rapid increase in growth (up to 2.5 log CFU/g) during the first 7 days of incubation, which may be indicative of the destruction of an endogenous growth-inhibiting compound within the cabbage. In conclusion, this study shows that mild thermal treatments of cut cabbage may promote pathogen growth if other inimical barriers are not implemented downstream of the thermal treatment.

Wetland eco-engineering: Measuring and modeling feedbacks of oxidation processes between plants and clay-rich material

NARCIS (Netherlands)

Saaltink, R.; Dekker, S.C.; Griffioen, J.; Wassen, M.J.

2016-01-01

Interest is growing in using soft sediment as a foundation in eco-engineering projects. Wetland construction in the Dutch lake Markermeer is an example: here, dredging some of the clay-rich lake-bed sediment and using it to construct wetland will soon begin. Natural processes will be utilized during

The new challenges of end-of-life tyres management systems: A Spanish case study

Energy Technology Data Exchange (ETDEWEB)

Uruburu, Ángel, E-mail: angel.uruburu@upm.es [Industrial Management Department, Technical University of Madrid, C/José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Ponce-Cueto, Eva, E-mail: eva.ponce@upm.es [Industrial Management Department, Technical University of Madrid, C/José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Center for Transportation and Logistics, Massachusetts Institute of Technology, Cambridge, MA (United States); Cobo-Benita, José Ramón, E-mail: joseramon.cobo@upm.es [Industrial Management Department, Technical University of Madrid, C/José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Ordieres-Meré, Joaquín, E-mail: j.ordieres@upm.es [Industrial Management Department, Technical University of Madrid, C/José Gutiérrez Abascal, 2, 28006 Madrid (Spain)

2013-03-15

Highlights: ► Impact of the implementation of the Directive 2008/98/EC in Spain for end-of-life tyres. ► Characterization of the reverse supply chain for collecting, recovering, and treating end-of-life tyres. ► Identification of challenges to be coped and issues to be covered. ► Potential new applications for end-of-life tyres and development of new management related strategies. - Abstract: Directive 2008/98/EC released by the European Union represents a significant step forward in all relevant aspects of waste management. Under the already established, extended produced responsibility (EPR) principle, new policies have been enunciated to continuously achieve better overall environmental performance of key products throughout their life phases. This paper discusses how the directive is being articulated in Spain by the main integrated management system (IMS) for end-of-life (EOL) tyres since its creation in 2006. Focusing on the IMS technological, economic and legal aspects, the study provides a global perspective and evaluation of how the IMS is facing the current issues to resolve, the new challenges that have appeared and the management vision for the coming years.

The new challenges of end-of-life tyres management systems: A Spanish case study

International Nuclear Information System (INIS)

Uruburu, Ángel; Ponce-Cueto, Eva; Cobo-Benita, José Ramón; Ordieres-Meré, Joaquín

2013-01-01

Highlights: ► Impact of the implementation of the Directive 2008/98/EC in Spain for end-of-life tyres. ► Characterization of the reverse supply chain for collecting, recovering, and treating end-of-life tyres. ► Identification of challenges to be coped and issues to be covered. ► Potential new applications for end-of-life tyres and development of new management related strategies. - Abstract: Directive 2008/98/EC released by the European Union represents a significant step forward in all relevant aspects of waste management. Under the already established, extended produced responsibility (EPR) principle, new policies have been enunciated to continuously achieve better overall environmental performance of key products throughout their life phases. This paper discusses how the directive is being articulated in Spain by the main integrated management system (IMS) for end-of-life (EOL) tyres since its creation in 2006. Focusing on the IMS technological, economic and legal aspects, the study provides a global perspective and evaluation of how the IMS is facing the current issues to resolve, the new challenges that have appeared and the management vision for the coming years

Effect of road surfacing condition on tyre life

CSIR Research Space (South Africa)

Steyn, WJvdM

2005-07-01

Full Text Available simple patching of potholes and sealing of cracks to a reseal of the road or even recycling and rehabilitation of the failed sections of the road. These maintenance actions affect the surfacing of the road and therefore the experience of the tyre...

New results on the relation between tyre-road longitudinal stiffness and maximum available grip for motor car

Science.gov (United States)

Andrieux, A.; Vandanjon, P. O.; Lengelle, R.; Chabanon, C.

2010-12-01

Tyre-road estimation methods have been the objective of many research programmes throughout the world. Most of these methods aim at estimating the friction components such as tyre longitudinal slip rate κ and friction coefficient μ in the contact patch area. In order to estimate the maximum available friction coefficient μmax, these methods generally use a probabilistic relationship between the grip obtained for low tyre excitations (such as constant speed driving) and the grip obtained for high tyre excitations (such as emergency braking manoeuvre). Confirmation or invalidation of this relationship from experimental results is the purpose of this paper. Experiments have been carried out on a reference track including several test boards corresponding to a wide textural spectrum. The main advantage of these experiments lies in the use of a vehicle allowing us to accurately build point-by-point relationship between κ and μ. This relationship has been determined for different tyres and pavement textures. Finally, the curves obtained are analysed to check the validity of the relationship between the current friction coefficient used by the car during normal driving conditions and μmax.

Effects on accidents of changes in the use of studded tyres in major cities in Norway

DEFF Research Database (Denmark)

Elvik, Rune; Fridstrøm, Lasse; Kaminska, Joanna

2013-01-01

This paper reports the findings of two studies made eleven years apart in Norway (0035 and 0025) to evaluate effects on accidents of changes in the use of studded tyres in major cities in Norway. The first study covered the period from 1991 to 2000, the second study covered the period from 2002...... to 2009. In both these periods, large changes in the percentage of cars using studded tyres were found in the cities that were included in the study. There was, in most cities, a tendency for the use of studded tyres to go down. Effects of these changes on injury accidents were evaluated by means...... of negative binomial regression models, using city and day as the unit of analysis, and including more than twenty explanatory variables in order to control for confounding factors. The effects of changes in the percentage of cars using studded tyres were well described by an accident modification function...

Measurement of stress distributions in truck tyre contact patch in real rolling conditions

Science.gov (United States)

Anghelache, Gabriel; Moisescu, Raluca

2012-12-01

Stress distributions on three orthogonal directions have been measured across the contact patch of truck tyres using the complex measuring system that contains a transducer assembly with 30 sensing elements placed in the road surface. The measurements have been performed in straight line, in real rolling conditions. Software applications for calibration, data acquisition, and data processing were developed. The influence of changes in inflation pressure and rolling speed on the shapes and sizes of truck tyre contact patch has been shown. The shapes and magnitudes of normal, longitudinal, and lateral stress distributions, measured at low speed, have been presented and commented. The effect of wheel toe-in and camber on the stress distribution results was observed. The paper highlights the impact of the longitudinal tread ribs on the shear stress distributions. The ratios of stress distributions in the truck tyre contact patch have been computed and discussed.

Thermochemical recycling of mixture of scrap tyres and waste lubricating oil into high caloric value products

International Nuclear Information System (INIS)

Abdul-Raouf, Manar E.; Maysour, Nermine E.; Abdul-Azim, Abdul-Azim A.; Amin, Mahasen S.

2010-01-01

Scrap tyres and used lubricating oils represent together growing environmental problem because they are not biodegradable and their components cannot readily be recovered. In the present investigation, the thermochemical recycling of mixture of old tyres with waste lubricating oil by pyrolysis and the value of the products obtained have been studied. First, thermobalance experiments were carried out, studying the influence of the following variables: temperature, type of catalyst and catalyst concentration on the pyrolysis reaction of a mixture of 1/1 wt./wt. oil/tyre ratio. These thermobalance results were thoroughly investigated to study the effect of the main process variables on yields of derived products: oils, gases and solid residue.

Modelling road dust emission abatement measures using the NORTRIP model: Vehicle speed and studded tyre reduction

Science.gov (United States)

Norman, M.; Sundvor, I.; Denby, B. R.; Johansson, C.; Gustafsson, M.; Blomqvist, G.; Janhäll, S.

2016-06-01

Road dust emissions in Nordic countries still remain a significant contributor to PM10 concentrations mainly due to the use of studded tyres. A number of measures have been introduced in these countries in order to reduce road dust emissions. These include speed reductions, reductions in studded tyre use, dust binding and road cleaning. Implementation of such measures can be costly and some confidence in the impact of the measures is required to weigh the costs against the benefits. Modelling tools are thus required that can predict the impact of these measures. In this paper the NORTRIP road dust emission model is used to simulate real world abatement measures that have been carried out in Oslo and Stockholm. In Oslo both vehicle speed and studded tyre share reductions occurred over a period from 2004 to 2006 on a major arterial road, RV4. In Stockholm a studded tyre ban on Hornsgatan in 2010 saw a significant reduction in studded tyre share together with a reduction in traffic volume. The model is found to correctly simulate the impact of these measures on the PM10 concentrations when compared to available kerbside measurement data. Importantly meteorology can have a significant impact on the concentrations through both surface and dispersion conditions. The first year after the implementation of the speed reduction on RV4 was much drier than the previous year, resulting in higher mean concentrations than expected. The following year was much wetter with significant rain and snow fall leading to wet or frozen road surfaces for 83% of the four month study period. This significantly reduced the net PM10 concentrations, by 58%, compared to the expected values if meteorological conditions had been similar to the previous years. In the years following the studded tyre ban on Hornsgatan road wear production through studded tyres decreased by 72%, due to a combination of reduced traffic volume and reduced studded tyre share. However, after accounting for exhaust

Pengujian Dan Analisa Anti Komputer Forensik Menggunakan Shred Tool

Directory of Open Access Journals (Sweden)

Budi Rahardjo

2016-08-01

Full Text Available Komputer forensik dan anti komputer forensik adalah dua bidang yang saling berlawanan. Komputer forensik dilakukan oleh ahli komputer forensik guna memperoleh data dan bukti akurat dari kasus cyber crime untuk penyelidikan, sedangkan anti komputer forensik dilakukan oleh attacker untuk menghilangkan jejak sekaligus menyulitkan ahli komputer forensik dalam melakukan tugasnya. Bagi attacker, pemilihan tool anti komputer forensik yang default di mesin target, dinilai lebih  efektif  dan  cepat  dibandingkan menginstalasi terlebih dahulu di  mesin korban. Untuk itu dipilihlah shred sebagai aplikasi anti komputer forensik pada mesin GNU/Linux. Jika anti forensik berhasil, ahli forensik akan sulit melakukan komputer forensik terhadap data yang menjadi barang bukti cyber crime. Paper ini memaparkan mengenai anti forensik yang dilakukan oleh attacker terhadap mesin remote GNU/Linux untuk kasus cyber crime di jaringan komputer. Anti forensik dilakukan menggunakan shred terhadap file syslog untuk menghapus jejak kejahatan sekaligus menyulitkan proses forensik oleh ahli komputer forensik. Pengujian dilakukan pada 3 buah komputer berbasis GNU/Linux pada intranet Lab Sinyal Sistem ITB. Masing - masing bertindak sebagai mesin target (server, mesin firewall, dan mesin attacker. Dilakukan proses anti komputer forensik dan komputer forensik di mesin server. Hasil pengujian dicatat dan dianalisa untuk kemudian ditarik kesimpulan.

Importance of tread inertia and damping on the tyre/road contact stiffness

Science.gov (United States)

Winroth, J.; Andersson, P. B. U.; Kropp, W.

2014-10-01

Predicting tyre/road interaction processes like roughness excitation, stick-slip, stick-snap, wear and traction requires detailed information about the road surface, the tyre dynamics and the local deformation of the tread at the interface. Aspects of inertia and damping when the tread is locally deformed are often neglected in many existing tyre/road interaction models. The objective of this paper is to study how the dynamic features of the tread affect contact forces and contact stiffness during local deformation. This is done by simulating the detailed contact between an elastic layer and a rough road surface using a previously developed numerical time domain contact model. Road roughness on length scales smaller than the discretisation scale is included by the addition of nonlinear contact springs between each pair of contact elements. The dynamic case, with an elastic layer impulse response extending in time, is compared with the case where the corresponding quasi-static response is used. Results highlight the difficulty of estimating a constant contact stiffness as it increases during the indentation process between the elastic layer and the rough road surface. The stiffness-indentation relation additionally depends on how rapidly the contact develops; a faster process gives a stiffer contact. Material properties like loss factor and density also alter the contact development. This work implies that dynamic properties of the local tread deformation may be of importance when simulating contact details during normal tyre/road interaction conditions. There are however indications that the significant effect of damping could approximately be included as an increased stiffness in a quasi-static tread model.

Compound soil-tyre chips modified by cement as a road construction material

Directory of Open Access Journals (Sweden)

Panu Promputthangkoon

2013-10-01

Full Text Available This research attempts to overcome the two problems of low-quality soil and a growing number of discarded tyres bymixing low-CBR soil with recycled tyre chips. The compound soil-tyre chips was then stabilised by Portland cement with theaim of using them as a new material in road construction in order to reduce the occurrence of shrinkage cracks. To achievethe purposes of this research three standard geotechnical testing programmes were employed: (1 modified compaction tests,(2 California Bearing Ratio tests (CBR, and (3 unconfined compression tests. The modified compaction test results provedthat for the mixtures having very low tyre chips and cement content, the behaviour is very complex. It was also observed thatthe greater the percentage of rubber added the lower the global density. However, this is predictable as the specific gravityof the rubber is much lower than that of the soil. For the relationship between the optimum moisture content (OMC and thecement content, it was observed that there is no clear pattern.For the specimens having no cement added, the CBR for unsoaked specimens was observed to be greater than that forsoaked specimens. However, when the cement was introduced the CBR test showed that the resistance to penetration for thesoaked specimens was significantly greater, indicating the effects of cement added on the strength. In addition, it was foundthat the CBR values for both soaked and unsoaked specimens gradually increased with the increase of cement content.Lastly, the unconfined compressive strength progressively increased with the increased percentage of cement.

Stress-in-motion (SIM) - tyre/road interface contact stresses

CSIR Research Space (South Africa)

De Beer, Morris

2012-06-01

Full Text Available Tyre or road interface stresses are those induced by vehicular traffic running on roads, and are the primary cause of surfacing problems. The cost of asphalt layers is often the most significant in road construction and maintenance work...

Mathematical models and qualities of shredded Thai-style instant rice under a combined gas-fired infrared and air convection drying

Science.gov (United States)

Nachaisin, Mali; Teeta, Suminya; Deejing, Konlayut; Pharanat, Wanida

2017-09-01

Instant food is a product produced for convenience for consumer. Qualities are an important attribute of food materials reflecting consumer acceptance. The most problem of instant rice is casehardening during drying process resulted in the longer rehydration time. The objective of this research was to study the qualities of shredded Thai-style instant rice under a combined gas-fired infrared and air convection drying. Additionally, the mathematical models for gas-fired infrared assisted thin-layer drying of shredded Thai-style rice for traditional was investigated. The thin-layer drying of shredded Thai-style rice was carried out under gas-fired infrared intensities of 1000W/m2, air temperatures of 70°C and air velocities of 1 m/s. The drying occurred in the falling rate of drying period. The Page model was found to satisfactorily describe the drying behavior of shredded Thai-style rice, providing the highest R2 (0.997) and the lowest MBE and RMSE (0.01 and 0.18) respectively. A 9 point hedonic test showed in softness and color, but odor and overall acceptance were very similar.

Thermochemical recycling of mixture of scrap tyres and waste lubricating oil into high caloric value products

Energy Technology Data Exchange (ETDEWEB)

Abdul-Raouf, Manar E.; Maysour, Nermine E.; Abdul-Azim, Abdul-Azim A. [Egyptian Petroleum Research Institute, Nasr City, Cairo (Egypt); Amin, Mahasen S. [Faculty of Science, Benha University, Benha (Egypt)

2010-06-15

Scrap tyres and used lubricating oils represent together growing environmental problem because they are not biodegradable and their components cannot readily be recovered. In the present investigation, the thermochemical recycling of mixture of old tyres with waste lubricating oil by pyrolysis and the value of the products obtained have been studied. First, thermobalance experiments were carried out, studying the influence of the following variables: temperature, type of catalyst and catalyst concentration on the pyrolysis reaction of a mixture of 1/1 wt./wt. oil/tyre ratio. These thermobalance results were thoroughly investigated to study the effect of the main process variables on yields of derived products: oils, gases and solid residue. (author)

Fine granular of shredded waste tyre for road kerb application as improvised road furniture

Science.gov (United States)

Munikanan, Vikneswaran; Yahya, Muhamad Azani; Yusof, Mohammed Alias; Radzi, Muhammad Haris Fauzan

2018-02-01

Solid waste management in Malaysia was still in a backward stage. Population growth, urbanization and rapid industrialization led to an increase in the solid waste generated by society. Solid waste management is one of the main problems faced by the community, especially in the city. Solid waste management costs of the collection, collecting, transporting waste to the landfill, is very high. The quantity of solid waste should be reduced in order to reduce government spending. Moreover, improper solid waste management caused a negative impact on people and the environment. Method of recycling is one of the best alternatives to reduce the number of solid waste. Therefore, this study was to identify methods of recycling used tires to be used in civil engineering. This study was conducted to determine the effectiveness and properties of rubber from used tires to be add in the road kerb design.

Tyres and the environment; Reifen und Umwelt

Energy Technology Data Exchange (ETDEWEB)

Poetscher, Friedrich [Umweltbundesamt GmbH, Wien (Austria). Verkehr und Laerm

2009-07-01

A large part of the population is exposed to nuisances to which traffic contributes significantly, e.g. noise, fine dust and climate-relevant gaseous emissions. In this context, the environmental characteristics of tyres are of great importance, i.e. rolling noise, wear, and rolling friction. To reduce environmental effects, more rigid legislation will be required. This is indicated, e.g., by a study carried out on behalf of the European Commission. To date, no significant correlations have been established between important tyre characteristics like noise, (wet) grip, and rolling friction, which indicates that there is definitely a potential for reduction here. There is already a draft regulation on rolling noise which will contain more rigid boundary values. In the field of fine dust, intensive efforts were made during the past few years to reduce environmental pollution, e.g. by incentive programmes for promoting retrofitting of diesel particulate filters. The available potential for emission reduction in this area is nearly exhausted; on the other hand, particulate emissions from wear and road dust resuspension are getting more attention and may soon be taken into consideration in air quality monitoring. (orig.)

Contribution to tyre noise measurement adapted to human ears to future optimisation of tyre/road noise; Was kann die gehoergerechte Schallmesstechnik zur zukunftsorientierten Gestaltung des Reifen-/Fahrbahngeraeusches beitragen?

Energy Technology Data Exchange (ETDEWEB)

Genuit, K. [HEAD acoustics, Herzogenrath-Kohlscheid (Germany); Poggenburg, J.

1998-12-31

The share of tyre noise in the total motor car noise has increased constantly in the past years. Today, legal regulations governing car noise and the car industry`s increasing demands on driving comfort are forcing car tyre producers to reduce tyre noise. This is made more difficult by the high and varied demands on tyres. The authors therefore suggest that rolling noise design should be given more attention supplementary to the current noise level measurements. This would result in a product-specific type of noise and also enhance the social acceptance of motor cars. The limits of conventional measuring techniques are pointed out, as are the possibilities of binaural measurement and analysis. Exemplary applications are listed, and an outlook to the future is attempted. [Deutsch] Der prozentuale Anteil der Reifen am Gesamtgeraeusch eines Fahrzeuges ist in der Vergangenheit stetig angestiegen. Bestehende gesetzliche Vorschriften fuer das Fahrzeug-Aussengeraeusch sowie hohe Ansprueche der Kunden, d.h. primaer der Automobilindustrie, zwingen die Reifenhersteller generell, das Rollgeraeusch zu reduzieren. Die an einen Fahrzeugreifen gestellten vielfaeltigen Anforderungen bedingen hierbei im allgemeinen einen hohen Aufwand. Im Beitrag wird daher fuer eine Vorgehensweise plaediert, die in Ergaenzung zum begrenzt aussagekraeftigen A-bewerteten Schalldruckpegel eine Gestaltung des Rollgeraeusches in den Mittelpunkt stellt. Hiermit kann nicht nur die Realisierung eines produktbezogenen Aussengeraeusches unterstuetzt werden, sondern es sichert darueber hinaus die gesellschaftliche Akzeptanz des Autos. Es werden die Grenzen konventioneller Messverfahren kurz aufgezeigt und die mittels binauraler Mess- und Analysetechnik bestehenden Moeglichkeiten dargestellt. Sinnvolle Vorgehensweisen werden anhand verschiedener Anwendungsbeispiele erlaeutert. Ein abschliessender Ausblick beschreibt das Potential zur Reduzierung der Belaestigungswirkung von Reifengeraeuschen durch

Geotechnical Characterization of Mined Clay from Appalachian Ohio: Challenges and Implications for the Clay Mining Industry

Science.gov (United States)

Moran, Anthony R.; Hettiarachchi, Hiroshan

2011-01-01

Clayey soil found in coal mines in Appalachian Ohio is often sold to landfills for constructing Recompacted Soil Liners (RSL) in landfills. Since clayey soils possess low hydraulic conductivity, the suitability of mined clay for RSL in Ohio is first assessed by determining its clay content. When soil samples are tested in a laboratory, the same engineering properties are typically expected for the soils originated from the same source, provided that the testing techniques applied are standard, but mined clay from Appalachian Ohio has shown drastic differences in particle size distribution depending on the sampling and/or laboratory processing methods. Sometimes more than a 10 percent decrease in the clay content is observed in the samples collected at the stockpiles, compared to those collected through reverse circulation drilling. This discrepancy poses a challenge to geotechnical engineers who work on the prequalification process of RSL material as it can result in misleading estimates of the hydraulic conductivity of the samples. This paper describes a laboratory investigation conducted on mined clay from Appalachian Ohio to determine how and why the standard sampling and/or processing methods can affect the grain-size distributions. The variation in the clay content was determined to be due to heavy concentrations of shale fragments in the clayey soils. It was also concluded that, in order to obtain reliable grain size distributions from the samples collected at a stockpile of mined clay, the material needs to be processed using a soil grinder. Otherwise, the samples should be collected through drilling. PMID:21845150

Geotechnical characterization of mined clay from Appalachian Ohio: challenges and implications for the clay mining industry.

Science.gov (United States)

Moran, Anthony R; Hettiarachchi, Hiroshan

2011-07-01

Clayey soil found in coal mines in Appalachian Ohio is often sold to landfills for constructing Recompacted Soil Liners (RSL) in landfills. Since clayey soils possess low hydraulic conductivity, the suitability of mined clay for RSL in Ohio is first assessed by determining its clay content. When soil samples are tested in a laboratory, the same engineering properties are typically expected for the soils originated from the same source, provided that the testing techniques applied are standard, but mined clay from Appalachian Ohio has shown drastic differences in particle size distribution depending on the sampling and/or laboratory processing methods. Sometimes more than a 10 percent decrease in the clay content is observed in the samples collected at the stockpiles, compared to those collected through reverse circulation drilling. This discrepancy poses a challenge to geotechnical engineers who work on the prequalification process of RSL material as it can result in misleading estimates of the hydraulic conductivity of the samples. This paper describes a laboratory investigation conducted on mined clay from Appalachian Ohio to determine how and why the standard sampling and/or processing methods can affect the grain-size distributions. The variation in the clay content was determined to be due to heavy concentrations of shale fragments in the clayey soils. It was also concluded that, in order to obtain reliable grain size distributions from the samples collected at a stockpile of mined clay, the material needs to be processed using a soil grinder. Otherwise, the samples should be collected through drilling.

Geotechnical Characterization of Mined Clay from Appalachian Ohio: Challenges and Implications for the Clay Mining Industry

Directory of Open Access Journals (Sweden)

Anthony R. Moran

2011-06-01

Full Text Available Clayey soil found in coal mines in Appalachian Ohio is often sold to landfills for constructing Recompacted Soil Liners (RSL in landfills. Since clayey soils possess low hydraulic conductivity, the suitability of mined clay for RSL in Ohio is first assessed by determining its clay content. When soil samples are tested in a laboratory, the same engineering properties are typically expected for the soils originated from the same source, provided that the testing techniques applied are standard, but mined clay from Appalachian Ohio has shown drastic differences in particle size distribution depending on the sampling and/or laboratory processing methods. Sometimes more than a 10 percent decrease in the clay content is observed in the samples collected at the stockpiles, compared to those collected through reverse circulation drilling. This discrepancy poses a challenge to geotechnical engineers who work on the prequalification process of RSL material as it can result in misleading estimates of the hydraulic conductivity of the samples. This paper describes a laboratory investigation conducted on mined clay from Appalachian Ohio to determine how and why the standard sampling and/or processing methods can affect the grain-size distributions. The variation in the clay content was determined to be due to heavy concentrations of shale fragments in the clayey soils. It was also concluded that, in order to obtain reliable grain size distributions from the samples collected at a stockpile of mined clay, the material needs to be processed using a soil grinder. Otherwise, the samples should be collected through drilling.

Coupled modelling (transport-reaction) of the fluid-clay interactions and their feed back on the physical properties of the bentonite engineered clay barrier system

International Nuclear Information System (INIS)

Marty, N.

2006-11-01

The originality of this work is to process feed back effects of mineralogical and chemical modifications of clays, in storage conditions, on their physical properties and therefore on their transport characteristics (porosity, molecular diffusion, permeability). These feed back effects are modelled using the KIRMAT code (Kinetic of Reaction and MAss Transfer) developed from the kinetic code KINDIS by adding the effect of water renewal in the mineral-solution reactive cells. KIRMAT resolves mass balance equations associated with mass transport together with the geochemical reactions in a 1D approach. After 100 000 years of simulated interaction at 100 C, with the fluid of the Callovo-Oxfordian geological level (COX) and with iron provided by the steel overpack corrosion, the montmorillonite of the clay barrier is only partially transformed (into illite, chlorite, saponite...). Only outer parts of the modelled profile seem to be significantly affected by smectite dissolution processes, mainly at the interface with the geological environment. The modifications of physical properties show a closure of the porosity at the boundaries of the barrier, by creating a decrease of mass transport by molecular diffusion, essentially at the interface with the iron. Permeability laws applied to this system show a decrease of the hydraulic conductivity correlated with the porosity evolution. Near the COX, the swelling pressure of the clays from the barrier decreases. In the major part of the modelled profile, the engineered clay barrier system seems to keep its initial physical properties (porosity, molecular diffusion, permeability, swelling pressure) and functionalities. (author)

Monitoring operational conditions of vehicle tyre pressure levels and ...

African Journals Online (AJOL)

Compliance with vehicle tyre inflation pressure and tread depth standard specifications and legal requirements were monitored by survey study in Kumasi Metropolis, Ghana. The survey covered 400 vehicles, comprising cars (28 %), medium buses (25 %), large capacity buses (15 %) and trucks (32 %). There were wide ...

On the impact of `smart tyres' on existing ABS/EBD control systems

Science.gov (United States)

Cheli, Federico; Leo, Elisbetta; Melzi, Stefano; Sabbioni, Edoardo

2010-12-01

The paper focuses on the possibility of enhancing the performances of the ABS (Antilock Braking System)/EBD (electronic braking distribution) control system by using the additional information provided by 'smart tyres' (i.e. tyres with embedded sensors and digital-computing capability). In particular, on the basis of previous works [Braghin et al., Future car active controls through the measurement of contact forces and patch features, Veh. Syst. Dyn. 44 (2006), pp. 3-13], the authors assumed that these components should be able to provide estimates for the normal loads acting on the four wheels and for the tyre-road friction coefficient. The benefits produced by the introduction of these additional channels into the existing ABS/EBD control logic were evaluated through simulations carried out with a validated 14 degrees of freedom (dofs) vehicle + ABS/EBD control logic numerical model. The performance of the ABS control system was evaluated through a series of braking manoeuvres on straight track focusing the attention on μ -jump conditions, while the performance of the EBD control system was assessed by means of braking manoeuvres carried out considering several weight distributions.

An investigation on the use of shredded waste PET bottles as aggregate in lightweight concrete

International Nuclear Information System (INIS)

Akcaoezoglu, Semiha; Atis, Cengiz Duran; Akcaoezoglu, Kubilay

2010-01-01

In this work, the utilization of shredded waste Poly-ethylene Terephthalate (PET) bottle granules as a lightweight aggregate in mortar was investigated. Investigation was carried out on two groups of mortar samples, one made with only PET aggregates and, second made with PET and sand aggregates together. Additionally, blast-furnace slag was also used as the replacement of cement on mass basis at the replacement ratio of 50% to reduce the amount of cement used and provide savings. The water-binder (w/b) ratio and PET-binder (PET/b) ratio used in the mixtures were 0.45 and 0.50, respectively. The size of shredded PET granules used in the preparation of mortar mixtures were between 0 and 4 mm. The results of the laboratory study and testing carried out showed that mortar containing only PET aggregate, mortar containing PET and sand aggregate, and mortars modified with slag as cement replacement can be drop into structural lightweight concrete category in terms of unit weight and strength properties. Therefore, it was concluded that there is a potential for the use of shredded waste PET granules as aggregate in the production of structural lightweight concrete. The use of shredded waste PET granules due to its low unit weight reduces the unit weight of concrete which results in a reduction in the death weight of a structural concrete member of a building. Reduction in the death weight of a building will help to reduce the seismic risk of the building since the earthquake forces linearly dependant on the dead-weight. Furthermore, it was also concluded that the use of industrial wastes such as PET granules and blast-furnace slag in concrete provides some advantages, i.e., reduction in the use of natural resources, disposal of wastes, prevention of environmental pollution, and energy saving.

An investigation on the use of shredded waste PET bottles as aggregate in lightweight concrete.

Science.gov (United States)

Akçaözoğlu, Semiha; Atiş, Cengiz Duran; Akçaözoğlu, Kubilay

2010-02-01

In this work, the utilization of shredded waste Poly-ethylene Terephthalate (PET) bottle granules as a lightweight aggregate in mortar was investigated. Investigation was carried out on two groups of mortar samples, one made with only PET aggregates and, second made with PET and sand aggregates together. Additionally, blast-furnace slag was also used as the replacement of cement on mass basis at the replacement ratio of 50% to reduce the amount of cement used and provide savings. The water-binder (w/b) ratio and PET-binder (PET/b) ratio used in the mixtures were 0.45 and 0.50, respectively. The size of shredded PET granules used in the preparation of mortar mixtures were between 0 and 4 mm. The results of the laboratory study and testing carried out showed that mortar containing only PET aggregate, mortar containing PET and sand aggregate, and mortars modified with slag as cement replacement can be drop into structural lightweight concrete category in terms of unit weight and strength properties. Therefore, it was concluded that there is a potential for the use of shredded waste PET granules as aggregate in the production of structural lightweight concrete. The use of shredded waste PET granules due to its low unit weight reduces the unit weight of concrete which results in a reduction in the death weight of a structural concrete member of a building. Reduction in the death weight of a building will help to reduce the seismic risk of the building since the earthquake forces linearly dependent on the dead-weight. Furthermore, it was also concluded that the use of industrial wastes such as PET granules and blast-furnace slag in concrete provides some advantages, i.e., reduction in the use of natural resources, disposal of wastes, prevention of environmental pollution, and energy saving.

Analysis on Wetting Deformation Properties of Silty Clay

Directory of Open Access Journals (Sweden)

Xinrong Liu

2014-06-01

Full Text Available Changes in water level that cause deformation and stability problems often occur in foundation pit engineering. Water damage is one of the main problems that will lead to disasters in foundation pit engineering. Research findings with regard to properties of wetting deformation due to water damage can be applied not only in foundation pit engineering, slope engineering, hydraulic engineering, and mining engineering but also in related issues in the field of theoretical research and practice. In this study, the characteristics of silty clay deformation after wetting are examined from the perspective of the effect of wetting on the side wall of foundation pit, and wetting experiments on silty clay of a selected area’s stratum located in Chongqing Municipality are conducted under different confining pressures and stress levels through a multi-function triaxial apparatus. Then, laws of silty clay wetting deformation are obtained, and the relationship between wetting stress level and wetting deformation amount is also figured out. The study reveals that the maximum values of wetting deformation under different confining pressures have appear at a particular stress level; therefore, the related measures should be taken to avoid this deformation in the process of construction.

Characterisation and catalytic upgrading of tars from coal-tyre hydropyrolysis

Energy Technology Data Exchange (ETDEWEB)

Mastral, A.M.; Murillo, R.; Callen, M.S.; Garcia, T. [Instituto de Carboquimica, Zaragoza (Spain)

1999-07-01

Tars from coal-tyre hydropyrolysis obtained in a swept fixed bed reactor were upgraded with catalysts. Upgraded oils were characterized, and naphtha, kerosene, gas oil, heavy gas oil and vacuum residue percentages were quantified. 7 refs., 3 tabs.

Waste truck-tyre processing by flash pyrolysis in a conical spouted bed reactor

International Nuclear Information System (INIS)

Lopez, G.; Alvarez, J.; Amutio, M.; Mkhize, N.M.; Danon, B.; Gryp, P.; Görgens, J.F. van der; Bilbao, J.; Olazar, M.

2017-01-01

Highlights: • Flash pyrolysis improves TPO and limonene yields vs. slow pyrolysis. • The most suitable temperature for TPO and limonene maximization was 475 °C. • Operating at 575 °C gas yields and char quality was enhanced. • Temperature showed a limited effect on sulphur distribution among products. - Abstract: The flash pyrolysis of waste truck-tyres was studied in a conical spouted bed reactor (CSBR) operating in continuous regime. The influence of temperature on product distribution was analysed in the 425–575 °C range. A detailed characterization of the pyrolysis products was carried out in order to assess their most feasible application. Moreover, special attention was paid to the sulphur distribution among the products. The analysis of gaseous products was carried out using a micro-GC and the tyre pyrolysis oil (TPO) by means of GC-FID using peak areas for quantification, with GC/MS for identification and elemental analysis. Finally, the char was subjected to elemental analysis and surface characterization. According to the results, 475 °C is an appropriate temperature for the pyrolysis of waste tyres, given that it ensures total devolatilisation of tyre rubber and a high TPO yield, 58.2 wt.%. Moreover, the quality of the oil is optimum at this temperature, especially in terms of high concentrations of valuable chemicals, such as limonene. An increase in temperature to 575 °C reduced the TPO yield to 53.9 wt.% and substantially changed its chemical composition by increasing the aromatic content. However, the quality of the recovered char was improved at high temperatures.

Clays in natural and engineered barriers for radioactive waste confinement - 5. International meeting. Book of abstracts

International Nuclear Information System (INIS)

2012-10-01

The purpose of this fifth international meeting is to bring again together specialists in the different disciplines related to clays and clay minerals, with scientists from organizations engaged in disposal of radioactive waste in order to evaluate the progress of the research conducted in that field. Multidisciplinary approaches including geology, mineralogy, geochemistry, rheology, physics and chemistry of clay minerals and assemblages are required in order to provide a detailed characterization of the geological host formations considered for the disposal of radioactive waste and to assess the behaviour of engineered and natural barriers when submitted to various types of perturbations induced by such facilities. The evaluation of the performances of the natural barrier as well as of the impact of repository-induced disturbances upon the confinement properties of clay-rich geological formations constitute major objectives for the experimental programs being and/or to be conducted in underground research laboratories, for interpreting the subsequent scientific results, for modelling the long-term behaviour of radioactive waste repositories and carrying out safety assessment exercises. The meeting covers all the aspects of clay characterization and behaviour considered at various times and space scales relevant to confinement of radionuclides in clay from basic phenomenological processes description, to the global understanding of the performance and safety at repository and geological scales. Special emphasis will be put on the modelling of processes occurring at the mineralogical level within the clay barriers. The topics covered by the program of the meeting are also supposed to be coherent with the general objectives proposed within the Strategic Research Agenda elaborated through the Implementing Geological Disposal of Radioactive Waste Technology Platform (IGD-TP). In this context, the meeting will also offer a particular opportunity to present the more

Possibility of obtaining hydrogen from coal/waste-tyre mixture

Czech Academy of Sciences Publication Activity Database

Kříž, Vlastimil; Brožová, Zuzana; Přibyl, Oldřich; Sýkorová, Ivana

2008-01-01

Roč. 89, č. 11 (2008), s. 1069-1075 ISSN 0378-3820 R&D Projects: GA ČR(CZ) GA105/07/1407 Institutional research plan: CEZ:AV0Z30460519 Keywords : hydrogen * coal * waste tyres Subject RIV: DD - Geochemistry Impact factor: 2.066, year: 2008 www.elsevier.com/locate/fuproc/

Resource recovery from end-of-life tyres in Greece: a field survey, state-of-art and trends.

Science.gov (United States)

Karagiannidis, A; Kasampalis, T

2010-06-01

Lack of consistent and available information for the entire tyre industry has often hindered adequate understanding of current and future issues that need to be addressed for improving the sustainable end-of-life tyre management. The aim of this paper is to review related best available technologies and techniques for Greece, ranging from simple mechanical processing, up to complex multistep, mechanochemical and/or thermal treatment. End-of-life tyre management guidelines in the form of a manual for supporting future entrepreneurs in this field are also discussed. Extensive data mining, classification and inventorying was performed, both in the field via questionnaires and in the literature, for the purpose of accurately determining Hellenic conditions, in order to pinpoint encountered problems, propose interventions and determine new entrepreneurship opportunities.

Impact of Oriented Clay Particles on X-Ray Spectroscopy Analysis

Science.gov (United States)

Lim, A. J. M. S.; Syazwani, R. N.; Wijeyesekera, D. C.

2016-07-01

Understanding the engineering properties of the mineralogy and microfabic of clayey soils is very complex and thus very difficult for soil characterization. Micromechanics of soils recognize that the micro structure and mineralogy of clay have a significant influence on its engineering behaviour. To achieve a more reliable quantitative evaluation of clay mineralogy, a proper sample preparation technique for quantitative clay mineral analysis is necessary. This paper presents the quantitative evaluation of elemental analysis and chemical characterization of oriented and random oriented clay particles using X-ray spectroscopy. Three different types of clays namely marine clay, bentonite and kaolin clay were studied. The oriented samples were prepared by placing the dispersed clay in water and left to settle on porous ceramic tiles by applying a relatively weak suction through a vacuum pump. Images form a Scanning Electron Microscope (SEM) was also used to show the comparison between the orientation patterns of both the sample preparation techniques. From the quantitative analysis of the X-ray spectroscopy, oriented sampling method showed more accuracy in identifying mineral deposits, because it produced better peak intensity on the spectrum and more mineral content can be identified compared to randomly oriented samples.

Parametrisation of a Maxwell model for transient tyre forces by means of an extended firefly algorithm

Directory of Open Access Journals (Sweden)

Andreas Hackl

2016-12-01

Full Text Available Developing functions for advanced driver assistance systems requires very accurate tyre models, especially for the simulation of transient conditions. In the past, parametrisation of a given tyre model based on measurement data showed shortcomings, and the globally optimal solution obtained did not appear to be plausible. In this article, an optimisation strategy is presented, which is able to find plausible and physically feasible solutions by detecting many local outcomes. The firefly algorithm mimics the natural behaviour of fireflies, which use a kind of flashing light to communicate with other members. An algorithm simulating the intensity of the light of a single firefly, diminishing with increasing distances, is implicitly able to detect local solutions on its way to the best solution in the search space. This implicit clustering feature is stressed by an additional explicit clustering step, where local solutions are stored and terminally processed to obtain a large number of possible solutions. The enhanced firefly algorithm will be first applied to the well-known Rastrigin functions and then to the tyre parametrisation problem. It is shown that the firefly algorithm is qualified to find a high number of optimisation solutions, which is required for plausible parametrisation for the given tyre model.

Adsorption of cellulases onto sugar beet shreds and modeling of the experimental data

Directory of Open Access Journals (Sweden)

Ivetić Darjana Ž.

2014-01-01

Full Text Available This study investigated the adsorption of cellulases onto sugar beet shreds. The experiments were carried out using untreated, as well as dried and not dried dilute acid and steam pretreated sugar beet shreds at different initial enzyme loads. Both dilute acid and steam pretreatment were beneficial in respect of cellulases adsorption providing 8 and 9 times higher amounts of adsorbed proteins, respectively, in comparison to the results obtained with the untreated substrate. Although the use of higher solids load enabled by drying of pretreated substrates, could be beneficial for process productivity, at the same time it decreases the adsorption of enzymes. The obtained experimental data were fitted to five adsorption models, and the Langmuir model having the lowest residual sum of squares was used for the determination of adsorption parameters which were used to calculate the strength of cellulases binding to the substrates.[Projekat Ministarstva nauke Republike Srbije, br. TR 31002

Modelling tyre-road contact stresses in pavement design and analysis

CSIR Research Space (South Africa)

Maina, JW

2013-07-01

Full Text Available between rolling tyres and the road structure it needs to be durable so as to withstand current traffic loading and hence contact stresses, given the environmental forces also acting on it. For road infrastructure to perform as expected, it is important...

The application of thermal processes to valorise waste tyre

Energy Technology Data Exchange (ETDEWEB)

Murillo, R.; Aylon, E.; Navarro, M.V.; Callen, M.S.; Aranda, A.; Mastral, A.M. [Instituto de Carboquimica, CSIC, M Luesma Castan 4, 50018-Zaragoza (Spain)

2006-01-15

Scrap tyres are a growing environmental problem because they are not biodegradable and their components cannot readily be recovered. In this investigation, the thermochemical recycling of rubber from old tyres by pyrolysis and the value of the products obtained have been studied. First, thermobalance experiments were carried out, studying the influence of the following variables: heating rate, flow rate, particle size and temperature. These thermobalance results were extended by performing experiments in a fixed bed reactor, studying the effect of the main process variables on yields of derived products: oils, gases and solid residue. The oils have been characterized using a combination of analytical techniques (TLC-FID, GC-MS and simulated distillation). No relationship between functional group composition of the oils determined by TLC-FID and process variables was found. The carbonaceous material obtained was characterized by N{sub 2} and CO{sub 2} adsorption. The possible uses of this char have been analyzed taking into account and calculating the emissions that would be produced if the char were burnt. (author)

The application of thermal processes to valorise waste tyre

International Nuclear Information System (INIS)

Murillo, R.; Aylon, E.; Navarro, M.V.; Callen, M.S.; Aranda, A.; Mastral, A.M.

2006-01-01

Scrap tyres are a growing environmental problem because they are not biodegradable and their components cannot readily be recovered. In this investigation, the thermochemical recycling of rubber from old tyres by pyrolysis and the value of the products obtained have been studied. First, thermobalance experiments were carried out, studying the influence of the following variables: heating rate, flow rate, particle size and temperature. These thermobalance results were extended by performing experiments in a fixed bed reactor, studying the effect of the main process variables on yields of derived products: oils, gases and solid residue. The oils have been characterized using a combination of analytical techniques (TLC-FID, GC-MS and simulated distillation). No relationship between functional group composition of the oils determined by TLC-FID and process variables was found. The carbonaceous material obtained was characterized by N 2 and CO 2 adsorption. The possible uses of this char have been analyzed taking into account and calculating the emissions that would be produced if the char were burnt. (author)

The durability of concrete containing recycled tyres as a partial replacement of fine aggregate

Science.gov (United States)

Syamir Senin, Mohamad; Shahidan, Shahiron; Syazani Leman, Alif; Othman, Nurulain; Shamsuddin, Shamrul-mar; Ibrahim, M. H. W.; Zuki, S. S. Mohd

2017-11-01

Nowadays, uncontrolled disposal of waste materials such as tyres can affect the environment. Therefore, careful management of waste disposal must be done in order to conserve the environment. Waste tyres can be use as a replacement for both fine aggregate and coarse aggregate in the production of concrete. This research was conducted to assess the durability of concrete containing recycled tyres which have been crushed into fine fragments to replace fine aggregate in the concrete mix. This study presents an overview of the use of waste rubber as a partial replacement of natural fine aggregate in a concrete mix. 36 concrete cubes measuring 100mm × 100mm × 100mm and 12 concrete cubes measuring 150mm × 150mm × 150mm were prepared and added with different percentages of rubber from recycled tyres (0%, 3%, 5% and 7%) as fine aggregate replacement. The results obtained show that the replacement of fine aggregate with 7% of rubber recorded a compressive strength of 43.7MPa while the addition of 3% of rubber in the concrete sample recorded a high compressive strength of 50.8MPa. This shows that there is a decrease in the strength and workability of concrete as the amount of rubber used a replacement for fine aggregate in concrete increases. On the other hand, the water absorption test indicated that concrete which contains rubber has better water absorption ability. In this study, 3% of rubber was found to be the optimal percentage as a partial replacement for fine aggregate in the production of concrete.

Pyrolysis of a waste from the grinding of scrap tyres.

Science.gov (United States)

Fernández, A M; Barriocanal, C; Alvarez, R

2012-02-15

The fibres that are used to reinforce tyres can be recovered as a waste in the process of grinding of scrap tyres. In this paper beneficiation through pyrolysis is studied since the fibres are made up of polymers with a small amount of rubber because the latter is difficult to separate. The experiments were performed at three temperatures (400, 550 and 900°C) in a horizontal oven. The three products - gas, oil and char - obtained from the pyrolysis were investigated. The composition of the gas was analyzed by means of gas chromatography. The oil was studied by gas chromatography and infrared spectroscopy. The char porous structure was determined by N(2) adsorption. In addition, the topography of the chars was studied by means of scanning electron microscopy (SEM). The products resulting from the pyrolysis of the fibres were compared with those obtained from scrap rubber. Copyright © 2011 Elsevier B.V. All rights reserved.

Steam gasification of tyre waste, poplar, and refuse-derived fuel: A comparative analysis

International Nuclear Information System (INIS)

Galvagno, S.; Casciaro, G.; Casu, S.; Martino, M.; Mingazzini, C.; Russo, A.; Portofino, S.

2009-01-01

In the field of waste management, thermal disposal is a treatment option able to recover resources from 'end of life' products. Pyrolysis and gasification are emerging thermal treatments that work under less drastic conditions in comparison with classic direct combustion, providing for reduced gaseous emissions of heavy metals. Moreover, they allow better recovery efficiency since the process by-products can be used as fuels (gas, oils), for both conventional (classic engines and heaters) and high efficiency apparatus (gas turbines and fuel cells), or alternatively as chemical sources or as raw materials for other processes. This paper presents a comparative study of a steam gasification process applied to three different waste types (refuse-derived fuel, poplar wood and scrap tyres), with the aim of comparing the corresponding yields and product compositions and exploring the most valuable uses of the by-products

Advantages of Concrete Mixing with Tyre Rubber

OpenAIRE

Mazyad Al-Fadhli *

2017-01-01

Strong waste administration is one of the major natural concerns everywhere throughout the world. Tire-rubber particles made out of tire chips, piece elastic, and a mix of tire chips and scrap elastic, where utilized to supplant mineral totals in cement. These particles were utilized to supplant 10% , 15% , 20%, and 25% of the aggregate mineral totals volume in cement.Using rubber aggregates in such applications can help to prevent pollution and overcome the problem of storing used tyres. Adv...

Large Strain Analysis of Electro-Osmosis Consolidation for Clays

NARCIS (Netherlands)

Yuan, J.

2015-01-01

Consolidation of soft clay creates a lot of problems in foundation engineering, because of the very low clay permeability and high compressibility. Primary consolidation takes a long time to complete if the material is left consolidating under atmospheric evaporation, and traditional dewatering

Kinetics of the Thermal Degradation of Granulated Scrap Tyres: a Model-free Analysis

Directory of Open Access Journals (Sweden)

Félix A. LÓPEZ

2013-12-01

Full Text Available Pyrolysis is a technology with a promising future in the recycling of scrap tyres. This paper determines the thermal decomposition behaviour and kinetics of granulated scrap tyres (GST by examining the thermogravimetric/derivative thermogravimetric (TGA/DTG data obtained during their pyrolysis in an inert atmosphere at different heating rates. The model-free methods of Friedman, Flynn-Wall-Ozawa and Coats-Redfern were used to determine the reaction kinetics from the DTG data. The apparent activation energy and pre-exponential factor for the degradation of GST were calculated. A comparison with the results obtained by other authors was made.DOI: http://dx.doi.org/10.5755/j01.ms.19.4.2947

Local effects of friction between car tyres and roads; Lokale Effekte der Reibung zwischen Pkw-Reifen und Fahrbahn

Energy Technology Data Exchange (ETDEWEB)

Fach, M.

2000-07-01

Local effects of friction in the contact surface of car tyres were measured and interpreted using specially developed or modified emthods of measurement. The sensors were used in test stands and in driving tests. - The results on local sliding and elastic deformations show that interaction of both components governs the friction forces between tyres and roads. Deformation slip and sliding slip occur jointly, leading to a characterstic shape of the friction-slip curve. A closed theory on the characteristics of tyre friction is presented. - Analogies are established between the local effects resulting from frictional load on the tyres and the methods of friction coeffcient analysis using the Darmstadt tyre sensors. The fundmental mechanisms are derived and presented. [German] Die Arbeit beschaeftigt sich mit der Messung und Interpretation lokaler Effekte der Reibung in der Aufstandsflaeche von Pkw-Reifen. Zur Messung dieser Effekte wurden im Rahmen der Arbeit Messmethoden geschaffen bzw. vorhandene Verfahren angepasst. Die Sensorik wurde auf Pruefstaenden und im Fahrversuch eingesetzt. - Die Ergebnisse zum lokalen Gleiten und zu den elastischen Deformationen zeigen, dass ein Zusammenspiel der beiden Komponenten fuer die Auspraegung von Reibkraeften zwischen Reifen und Strasse massgeblich ist. Es entsteht das gemeinsame Auftreten von Deformations- und Gleitschlupf am Reifen und damit das charakteristische Aussehen der Reibwert-Schlupf-Kurve. Eine geschlossene Theorie zur Charakteristik der Reifenreibung wird vorgestellt. - Daneben zeigen sich deutliche Analogien zwischen den lokalen Effekten in Folge von Reibwertbeanspruchung vom Reifen und der Verfahren zur Reibwerterkennung mit Hilfe der Darmstaedter Reifensensorik. Die grundlegenden Mechanismen dafuer werden hergeleitet. (orig.)

ASSESSMENT OF SELECTED PROPERTIES OF NORMAL CONCRETES WITH THE GRINDED RUBBER FROM WORN OUT VEHICLE TYRES

Directory of Open Access Journals (Sweden)

Ewa Ołdakowska

2015-07-01

Full Text Available Rubber from the worn tyres is associated with a useless material, strenuous for environment, whose most popular recovery method until recently was storage (currently forbidden by law. The adoption and dissemination of new ecological standards, created not only by the European and national legislation, but also developing as a result of expanding ecological consciousness, forces the necessity of seeking efficient methods of utilization of the vehicle tyres. The exemplary solution for the problem of tyres withdrawn from the operation, presented in the article, is using them in the grinded form as a substitute for the natural aggregate for the production of normal concrete. The article presents the results of the tests of selected properties of the modified normal concrete, upon the basis of which it has been found that the rubber causes decrease of compression strength, concrete weight, limits water absorbability, and does not influence significantly the physical and chemical phenomena accompanying the composite structure formation.

Artificial soils and waste products. Theme report 2

Energy Technology Data Exchange (ETDEWEB)

O`Riordan, N.J. [Ove Arup and Partners, London (United Kingdom); Tammirinne, M. [Technical Research Centre of Finland (Finland); Skarzynska, K. [University of Agriculture, Krakow, (Poland)

1995-05-01

Increasing pressure to minimise waste, recycle and manage finite aggregate resources has lead to the use of waste materials for engineered fills. Techniques to deal with materials such as colliery waste and power station ashes are maturing. Other materials such as lime stabilised soils, tyre/soil and polystyrene soil mixtures are being investigated. As efforts to reduce waste continue, so greater demands will be placed upon engineered land filling. This report summarises current practice and applications in this important area of geotechnical activity. Increasing economic and political pressure to reduce waste will lead to the development of many hybrid soils and the reuse of waste materials in innovative ways: thereby extending the chain of utility. Major advances in the understanding of real soils and pore fluids will enable additives such as cements, shredded tyres, expanded polystyrene, etc, to be incorporated with confidence to produce useful and durable engineering materials with predictable behaviour. Large stockpiles of mineral wastes provide a potential source of secondary aggregates. A flexible approach to the specification of engineering materials is needed so that such waste can be reused. Evidence from the reuse of colliery and other waste materials suggests that tunneling spoil can be treated to produce potentially useful secondary aggregates. Material delivered to materials suggests that tunneling spoil can be trated to produce potentially useful secondary aggregates. Material delivered to landfill sites will become progressively higher in contamination content which will place greater demands upon containment systems. Formalised risk assessment of landfill containment systems will grow, and further research in definition of failure scenarios and probability of occurrence is necessary. (AB) 71 refs.

Mixtures of rubber tyre and plastic wastes pyrolysis: A kinetic study

International Nuclear Information System (INIS)

Miranda, Miguel; Cabrita, I.; Pinto, Filomena; Gulyurtlu, I.

2013-01-01

The study performed aimed at analysing possible routes for pyrolysis reaction mechanisms of polymeric materials namely RT (rubber tyre) and plastic wastes (PE (polyethylene), PP (polypropylene) and PS (polystyrene)). Consequently, and seeking sustainable transformation of waste streams into valuable chemicals and renewable liquid fuels, mixture of 30% RT, 20% PE, 30% PP and 20% PS was subjected to pyrolysis. Different kinetic models were studied using experimental data. None of the mechanisms found in literature led to a numerical adjustment and different pathways were investigated. Kinetic studies were performed aiming to evaluate direct conversions into new solid, liquid and gaseous products and if parallel reactions and/or reversible elementary steps should be included. Experiments were performed in batch system at different temperatures and reaction times. Kinetic models were evaluated and reaction pathways were proposed. Models reasonably fit experimental data, allow explaining wastes thermal degradation. Kinetic parameters were estimated for all temperatures and dependence of Ea and pre-exponential factor on temperature was evaluated. The rate constant of some reactions exhibited nonlinear temperature dependence on the logarithmic form of Arrhenius law. This fact strongly suggests that temperature has a significant effect on reaction mechanism of pyrolysis of mixtures of rubber tyre and plastic wastes. - Highlights: • Kinetic study of rubber tyre (RT) and different plastic wastes (PE, PP and PS) was performed in batch reactor. • Definition of possible pathways taken into account for the formation of final products. • Kinetic parameters were estimated. • The effect of reaction temperature and reaction time on liquid composition was performed

A preliminary study for an engineering assessment of a shallow land burial facility in clay

International Nuclear Information System (INIS)

Fitzpatrick, J.; Murray, N.

1987-02-01

This study characterises a notional low-level waste repository site within the Oxford clay belt, provides a conceptual design for a shallow, engineered repository at the site, and presents a rationale of the multiple-barrier design basis in sufficient detail to enable BRE to rehearse an engineering assessment. Parameters are identified which describe the repository's structural integrity, permeability and effectiveness in physical and chemical containment of nuclides by resistance to diffusive and advective transport. Such parameters may be used by the DoE as input for the mathematical modelling of the repository's post-closure performance under various release scenarios, as part of a full radiological assessment. Limitations in the analytical methods and experience base available for such assessments are identified and suggestions are made for future research activities. (author)

Investigation of the Storage Behavior of Shredded Lithium-Ion Batteries from Electric Vehicles for Recycling Purposes.

Science.gov (United States)

Grützke, Martin; Krüger, Steffen; Kraft, Vadim; Vortmann, Britta; Rothermel, Sergej; Winter, Martin; Nowak, Sascha

2015-10-26

Shredding of the cells is often the first step in lithium-ion battery (LIB) recycling. Thus, LiNi1/3 Mn1/3 Co1/3 O2 (NMC)/graphite lithium-ion cells from a field-tested electric vehicle were shredded and transferred to tinplate or plastic storage containers. The formation of hazardous compounds within, and being released from, these containers was monitored over 20 months. The tinplate cans underwent fast corrosion as a result of either residual charge in the active battery material, which could not fully be discharged because of contact loss to the current collector, or redox reactions between the tinplate surface and metal parts of the shredded material. The headspace compositions of the containers were investigated at room temperature and 150 °C using headspace-gas chromatography-mass spectrometry (HS-GC-MS). Samples of the waste material were also collected using microwave-assisted extraction and the extracts were analyzed over a period of 20 months using ion chromatography-electrospray ionization-mass spectrometry (IC-ESI-MS). LiPF6 was identified as a conducting salt, whereas dimethyl carbonate, ethyl methyl carbonate, and ethylene carbonate were the main solvent components. Cyclohexylbenzene was also detected, which is an additive for overcharge protection. Diethyl carbonate, fluoride, difluorophosphate and several ionic and non-ionic alkyl (fluoro)phosphates were also identified. Importantly, dimethyl fluorophosphate (DMFP) and diethyl fluorophosphate (DEFP) were quantified using HS-GC-MS through the use of an internal standard. DMFP, DEFP, and related compounds are known as chemical warfare agents, and the presence of these materials is of great interest. In the case of this study, these hazardous materials are present but in manageable low concentrations. Nonetheless, the presence of such compounds and their potential release during an accident that may occur during shredding or recycling of large amounts of LIB waste should be considered. © 2015

An appraisal of mass differences between individual tyres, axles and axle groups of a selection of heavy vehicles in South Africa

CSIR Research Space (South Africa)

De Beer, Morris

2012-06-01

Full Text Available study of 2 666 heavy vehicles (HVs) with Gross Combination Mass, (GCM) > 3 500 kg was conducted, where the mass (or weight) of each tyre (approximately 47 242 tyres (or wheels)) was measured. The measurements were done at slow speed over the SIM device...

A waveguide finite element aided analysis of the wave field on a stationary tyre, not in contact with the ground

Science.gov (United States)

Sabiniarz, Patrick; Kropp, Wolfgang

2010-07-01

Although tyre/road noise has been a research subject for more than three decades, there is still no consensus in the literature as to which waves on a tyre are mainly responsible for the radiation of sound during rolling. Even the free vibrational behaviour of a stationary (non-rotating) tyre, not in contact with the ground, is still not well understood in the mid- and high-frequency ranges. Thus, gaining an improved understanding of this behaviour is a natural first step towards illuminating the question of which waves on a rolling tyre contribute to sound radiation. This is the topic of the present paper, in which a model based on the waveguide finite element method (WFEM) is used to study free wave propagation, on a stationary tyre, in the range 0-1500 Hz. In the low-frequency region (0-300 Hz), wave propagation is found to be rather straightforward, with two main wave-types present. Both have cross-section modes involving a nearly rigid motion of the belt. For higher frequencies (300-1500 Hz) the behaviour is more complex, including phenomena such as 'curve veering' and waves for which the phase speed and group speed have opposite signs. Wave-types identified in this region include (i) waves involving mainly sidewall deformation, (ii) belt bending waves, (iii) a wave with significant extensional deformation of the central belt region and (iv) a wave with a 'breathing' cross-section mode. The phase speed corresponding to found waves is computed and their radiation efficiency is discussed, assuming free-field conditions. In a future publication, the tyre model will be used in conjunction with a contact model and a radiation model to investigate the contribution of these waves to radiated sound during rolling.

Aromatization of oils from coal-tyre cothermolysis. Part 2. PAH content study as a function of the process variables

Energy Technology Data Exchange (ETDEWEB)

Mastral, A.M.; Callen, S.; Garcia, T.; Navarro, M.V. [Department of Energy and Environmental, Instituto de Carboquimica CSIC, P.O. Box 589, C/Maria de Luna, 12, 50015, Zaragoza (Spain)

2000-10-01

In this work, the PAH content in the oils obtained from hydro-cothermolysis have been analysed. The influence of the process variables (H{sub 2} pressure, 1 and 10 MPa, different feed materials: coal, tyre and a blend of coal-tyre (1:1 in organic matter) in two reactors, tubing bomb and autoclave reactors (TBR, AR)), on PAH formation has been studied.Gas chromatography/mass spectrometry (GC/MS) is used as the main analytical technique after fractionation into four chemical fractions using neutral alumina column chromatography (CC). As the complementary technique, thin layer chromatography with flame ionisation detector (TLC/FID) was used to compare the analytical tool on the total aromatic compounds, leading to the conclusion that the nature of synthetic oils is also dependent on the analytical technique.In relation to the variables studied, the lower the pressure the higher the concentration of PAH detected. The hydrogen abundance reduces the PAH content. The hydropyrolysis of tyre, coal, and a blend of coal-tyre at the same conditions show that coal produces higher concentrations of PAH at hydrogenating conditions. PAHs that contain three and four cycles are the main PAHs detected regardless of the feed.

Tyre-road grip coefficient assessment - Part II: online estimation using instrumented vehicle, extended Kalman filter, and neural network

Science.gov (United States)

Luque, Pablo; Mántaras, Daniel A.; Fidalgo, Eloy; Álvarez, Javier; Riva, Paolo; Girón, Pablo; Compadre, Diego; Ferran, Jordi

2013-12-01

The main objective of this work is to determine the limit of safe driving conditions by identifying the maximal friction coefficient in a real vehicle. The study will focus on finding a method to determine this limit before reaching the skid, which is valuable information in the context of traffic safety. Since it is not possible to measure the friction coefficient directly, it will be estimated using the appropriate tools in order to get the most accurate information. A real vehicle is instrumented to collect information of general kinematics and steering tie-rod forces. A real-time algorithm is developed to estimate forces and aligning torque in the tyres using an extended Kalman filter and neural networks techniques. The methodology is based on determining the aligning torque; this variable allows evaluation of the behaviour of the tyre. It transmits interesting information from the tyre-road contact and can be used to predict the maximal tyre grip and safety margin. The maximal grip coefficient is estimated according to a knowledge base, extracted from computer simulation of a high detailed three-dimensional model, using Adams® software. The proposed methodology is validated and applied to real driving conditions, in which maximal grip and safety margin are properly estimated.

Performance of Kaolin Clay on the Concrete Pavement

Science.gov (United States)

Abdullah, M. E.; Jaya, R. P.; Shahafuddin, M. N. A.; Yaacob, H.; Ibrahim, M. H. Wan; Nazri, F. M.; Ramli, N. I.; Mohammed, A. A.

2018-05-01

This paper investigates the performance of concrete pavement containing kaolin clay with their engineering properties and to determine the optimum kaolin clay content. The concrete used throughout the study was designed as grade 30 MPa strength with constant water to cement ratio of 0.49. The compressive strength, flexural strength and water absorption test was conducted in this research. The concrete mix designed with kaolin clay as cement replacement comprises at 0%, 5%, 10% and 15% by the total weight of cement. The results indicate that the strength of pavement concrete decreases as the percentage of kaolin clay increases. It also shows that the water absorption increases with the percentage of cement replacement. However, 5% kaolin clay is found to be the optimum level to replace cement in a pavement concrete.

A tyre slip-based integrated chassis control of front/rear traction distribution and four-wheel independent brake from moderate driving to limit handling

Science.gov (United States)

Joa, Eunhyek; Park, Kwanwoo; Koh, Youngil; Yi, Kyongsu; Kim, Kilsoo

2018-04-01

This paper presents a tyre slip-based integrated chassis control of front/rear traction distribution and four-wheel braking for enhanced performance from moderate driving to limit handling. The proposed algorithm adopted hierarchical structure: supervisor - desired motion tracking controller - optimisation-based control allocation. In the supervisor, by considering transient cornering characteristics, desired vehicle motion is calculated. In the desired motion tracking controller, in order to track desired vehicle motion, virtual control input is determined in the manner of sliding mode control. In the control allocation, virtual control input is allocated to minimise cost function. The cost function consists of two major parts. First part is a slip-based tyre friction utilisation quantification, which does not need a tyre force estimation. Second part is an allocation guideline, which guides optimally allocated inputs to predefined solution. The proposed algorithm has been investigated via simulation from moderate driving to limit handling scenario. Compared to Base and direct yaw moment control system, the proposed algorithm can effectively reduce tyre dissipation energy in the moderate driving situation. Moreover, the proposed algorithm enhances limit handling performance compared to Base and direct yaw moment control system. In addition to comparison with Base and direct yaw moment control, comparison the proposed algorithm with the control algorithm based on the known tyre force information has been conducted. The results show that the performance of the proposed algorithm is similar with that of the control algorithm with the known tyre force information.

Temperature effect on the behaviour of engineered clay barriers

International Nuclear Information System (INIS)

Tang, A.M.

2005-11-01

The present work deals with the thermo-hydro-mechanical behaviour of compacted swelling clay used for engineered barriers in high-level radioactive repositories. The MX80 bentonite was chosen for this work. Firstly, an experimental work on the thermal conductivity of the compacted bentonite was performed. The results evidenced the effects of dry density, water content, volumetric fraction of soil components, microstructure, and mineralogy. This experimental work gave rise to the proposition of a theoretical model for estimate the thermal conductivity of compacted bentonites. Secondly, after a calibration of suction generated by saturated saline solution in function of temperature, water retention curves were determined at different temperatures. The experimental results showed a decrease of the water retention capacity of soil after heating. A simple model based on the interfacial tension air-water was formulated to simulate this effect. Thirdly, a new isotropic cell enabling a simultaneous control of suction, temperature and mechanical stress was developed. With this new cell, an experimental work on the thermo-mechanical behaviour of the unsaturated compacted bentonite was performed. Finally, a constitutive model was developed for simulate the thermo-hydro-mechanical behaviours obtained experimentally. (author)

Project Opalinus clay Zuercher Weinland of Nagra. Evaluation of the geo-scientific data base and of the construction engineering aspects

International Nuclear Information System (INIS)

2005-02-01

In this report the Commission for Nuclear Waste Management (KNE) assesses the geological and engineering aspects of the project Opalinus Clay, in which Nagra demonstrates the postclosure safety of geological disposal of spent fuel (SF), vitrified high-level wastes (HLW) and intermediate-level wastes (ILW) in a repository in the Opalinus Clay of the Zuercher Weinland in northern Switzerland. After in-depth examination of the geological database, KNE concludes that the demonstration of a suitable geological site for final disposal of SF, HLW and ILW in the Opalinus Clay of the Zuercher Weinland has been achieved. The geological assumptions Nagra uses for the assessment of long-term safety are based on data that have been carefully collected and interpreted. KNE acknowledges that Nagra interpreted the geological data correctly and adequately using state-of-the-art techniques. In case of lacking information, Nagra has used conservative or worst-case assumptions. The information documented by Nagra represents a good synthesis of field, laboratory and literature data. The tectonic situation of the Zuercher Weinland was examined in great details by Nagra. In the centre of the investigated region, where the Opalinus Clay occurs at 600 to 750 meters depth, the 3D-seismic data confirm its undisturbed stratification in an area of about 15 km 2 . Analysis and interpretation of the available information on the geological evolution provides no indication that erosion would expose the confining units above the Opalinus Clay within the next million years. The Opalinus Clay in the Zuercher Weinland is quite homogeneous and about 110 m thick. The properties of this rock are examined and found to be favourable for a repository. The dominance of the fine grain size and the high clay content indicate a very low hydraulic conductivity suitable for the isolation of radioactive wastes. Pore water extracted from drill-core samples is saline and has remained trapped for millions of years

Co-gasification of a lignite/waste-tyre in a moving bed

Czech Academy of Sciences Publication Activity Database

Straka, Pavel; Bučko, Z.

2009-01-01

Roč. 90, č. 10 (2009), s. 1202-1206 ISSN 0378-3820 R&D Projects: GA ČR(CZ) GA105/07/1407 Institutional research plan: CEZ:AV0Z30460519 Keywords : co-gasification * waste-tyre * lignite Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.321, year: 2009

Use of shredded tire chips and tire crumbs as packing media in trickling filter systems for landfill leachate treatment.

Science.gov (United States)

Mondal, B; Warith, M A

2008-08-01

Scrap tire stockpiles are breeding grounds for pests, mosquitoes and west Nile viruses and, thereby, become a potential health risk. This experimental study was carried out in six stages to determine the suitability of shredded tire materials in a trickling filter system to treat landfill leachate. Biochemical oxygen demand (BOD5), chemical oxygen demand (COD) and NH3-N removals were obtained in the range of 81 to 96%, 76 to 90% and 15 to 68%, respectively. The removal of organics appears to be largely related to total dissolved solids reduction in leachate. A sudden increase, from time to time, in organic content of effluent could be attributed to biomass sloughing and clogging in the trickling filters. However, tire crumbs exhibited more consistent organics removal throughout the experimental program. Due to the high surface area of shredded tire chips and crumbs, a layer of biomass, 1-2 mm thick, was attached to them and was sloughed off at an interval of 21 days. Apart from that, as shredded tires are comparatively cheaper than any other usable packing material, tire chips and tire crumbs appeared to be quite promising as packing media in trickling filters for landfill leachate treatment.

Horn amplification at a tyre/road interface. Pt. 1. Experiment and computation; Tire/romenkan ni okeru horn koka. Jikken to keisan

Energy Technology Data Exchange (ETDEWEB)

Fujikawa, T. [Japan Automobile Research Institute Inc., Tsukuba (Japan)

2000-01-01

Tyre/road interface noise can be amplified by a horn type space formed by the tread face of the tyre and the road. This paper is a report on studies on experiment and computation to elucidate the above phenomenon in detail. Measurement and computation were carried out on a tyre replaced with a single cylinder, whereas it was verified that the horn effect by each frequency can be calculated by BEM computation. Then, discussions were given on actual tyres combined with the BEM computation, and the following results were acquired: (1) the horn effect is small in zones of low frequencies; (2) the larger the tread width, the larger the horn effect increases; (3) the relationship between the tread width and the horn effect is governed by the ratio of the road contact width to noise wavelength; (4) the frequency characteristics of the horn effect vary largely according to whether the sound source exists in forward or rearward locations; (5) the relationship between the forward and rearward locations of the sound source with the horn effect is governed by the distance between the front and rear ends of the road contact face of the tyre; (6) the smaller the radius of the tread shoulder, the greater the horn effect; (7) tread deformation due to load applied on the tyre slightly changes the frequency characteristics of the horn effect; (8) with the sound source existing closer to the center of ground contacting width, the horn effect increases; and (9) the present study has verified the horn effect of 22 dB as the maximum. If the sound source is not present at the center of ground contacting width, the horn effect is reduced to about 10 dB, but the value cannot be ignored as the influence on traffic noise. (translated by NEDO)

Mineralogy and geotechnical characteristics of some pottery clay

Directory of Open Access Journals (Sweden)

Mujib Olamide ADEAGBO

2016-12-01

Full Text Available The physical properties of soils, which are tremendously influenced by the active clay minerals in soil, are of great importance in geotechnical engineering. This paper investigates the clay-sized particles of the Igbara-Odo pottery clay, and compares results obtained with available data on the bulk sample, to determine their correlation and underline the dependence of the geotechnical properties of the bulk clay material on the clay-sized particles. The bulk clay sample consists of 52% sand-size particles, 21% silt and 27% clay. Analysis of the clay-sized particles and the bulk materials shows: specific gravity of 2.07 and 2.66, liquid limit of 91.0% and 33.0%, plastic limit of 27.5% and 14.3%, plasticity index of 63.5% and 18.7% and a linear shrinkage of 7.9% and 5.4%, for both clay-sized particles and bulk clay respectively. The activity value of the clay material (0.64 suggests the presence of Kaolinite and Ilite; and these were confirmed with X-Ray diffraction on the bulk sample and clay-sized particles. X-Ray diffraction patterns shows distinctive peaks which highlight the dominance of Kaolinite (with 8 peaks in the pottery clay sample for both clay-sized particles and bulk material; while traces of other clay minerals like Illite and Halloysite and rock minerals like Mica, Feldspar and Chrysotile were also found. These results suggest that the clay possesses high viability in the manufacturing of ceramics, refractory bricks, paper, fertilizer and paint. The clay material can be used as a subgrade in road construction, since it possesses low swelling characteristics.

A model for prediction of the transient rolling resistance of tyres based on inner-liner temperatures

Science.gov (United States)

Greiner, Matthias; Unrau, Hans-Joachim; Gauterin, Frank

2018-01-01

Measurements of rolling resistance in thermal equilibrium of a tyre, like measurements according to ISO 28580, do not allow statements about rolling resistances under other driving conditions. Such statements, however, are necessary to determine the energy consumption in driving cycles. Especially for the proper calculation of electric-vehicle remaining ranges and the selection of the respective driving strategies, the real amount of energy consumption is required. This paper presents a model approach, which by means of only one standardised rolling resistance measurement can be parameterised and, considering the present driving speed and tyre temperature, can predict the respective current rolling resistance.

Time domain contact model for tyre/road interaction including nonlinear contact stiffness due to small-scale roughness

Science.gov (United States)

Andersson, P. B. U.; Kropp, W.

2008-11-01

Rolling resistance, traction, wear, excitation of vibrations, and noise generation are all attributes to consider in optimisation of the interaction between automotive tyres and wearing courses of roads. The key to understand and describe the interaction is to include a wide range of length scales in the description of the contact geometry. This means including scales on the order of micrometres that have been neglected in previous tyre/road interaction models. A time domain contact model for the tyre/road interaction that includes interfacial details is presented. The contact geometry is discretised into multiple elements forming pairs of matching points. The dynamic response of the tyre is calculated by convolving the contact forces with pre-calculated Green's functions. The smaller-length scales are included by using constitutive interfacial relations, i.e. by using nonlinear contact springs, for each pair of contact elements. The method is presented for normal (out-of-plane) contact and a method for assessing the stiffness of the nonlinear springs based on detailed geometry and elastic data of the tread is suggested. The governing equations of the nonlinear contact problem are solved with the Newton-Raphson iterative scheme. Relations between force, indentation, and contact stiffness are calculated for a single tread block in contact with a road surface. The calculated results have the same character as results from measurements found in literature. Comparison to traditional contact formulations shows that the effect of the small-scale roughness is large; the contact stiffness is only up to half of the stiffness that would result if contact is made over the whole element directly to the bulk of the tread. It is concluded that the suggested contact formulation is a suitable model to include more details of the contact interface. Further, the presented result for the tread block in contact with the road is a suitable input for a global tyre/road interaction model

A Study of Clay-Epoxy Nanocomposites Consisting of Unmodified Clay and Organo Clay

Directory of Open Access Journals (Sweden)

Graham Edward

2006-04-01

Full Text Available Clay-epoxy nanocomposites were synthesized from DGEBA resin and montmorillonite clay with an in-situ polymerization. One type of untreated clay and two types of organo clay were used to produce the nanocompsoites. The aims of this study were to examine the nanocomposite structure using different tools and to compare the results between the unmodified clay and modified clays as nanofillers. Although diffractogram in reflection mode did not show any apparent peak of both types of materials, the transmitted XRD (X-Ray Difraction graphs, DSC (Differential Scanning Calorimeter analysis and TEM (Transmission Electron Microscope images revealed that the modified clay-epoxy and unmodified clay-epoxy provides different results. Interestingly, the micrographs showed that some of the modified clay layers possessed non-exfoliated layers in the modified clay-epoxy nanocomposites. Clay aggregates and a hackle pattern were found from E-SEM images for both types of nanocomposite materials. It is shown that different tools should be used to determine the nanocomposite structure.

Assessment of the mechanical properties of sisal fiber-reinforced silty clay using triaxial shear tests.

Science.gov (United States)

Wu, Yankai; Li, Yanbin; Niu, Bin

2014-01-01

Fiber reinforcement is widely used in construction engineering to improve the mechanical properties of soil because it increases the soil's strength and improves the soil's mechanical properties. However, the mechanical properties of fiber-reinforced soils remain controversial. The present study investigated the mechanical properties of silty clay reinforced with discrete, randomly distributed sisal fibers using triaxial shear tests. The sisal fibers were cut to different lengths, randomly mixed with silty clay in varying percentages, and compacted to the maximum dry density at the optimum moisture content. The results indicate that with a fiber length of 10 mm and content of 1.0%, sisal fiber-reinforced silty clay is 20% stronger than nonreinforced silty clay. The fiber-reinforced silty clay exhibited crack fracture and surface shear fracture failure modes, implying that sisal fiber is a good earth reinforcement material with potential applications in civil engineering, dam foundation, roadbed engineering, and ground treatment.

Assessment of the Mechanical Properties of Sisal Fiber-Reinforced Silty Clay Using Triaxial Shear Tests

Directory of Open Access Journals (Sweden)

Yankai Wu

2014-01-01

Full Text Available Fiber reinforcement is widely used in construction engineering to improve the mechanical properties of soil because it increases the soil’s strength and improves the soil’s mechanical properties. However, the mechanical properties of fiber-reinforced soils remain controversial. The present study investigated the mechanical properties of silty clay reinforced with discrete, randomly distributed sisal fibers using triaxial shear tests. The sisal fibers were cut to different lengths, randomly mixed with silty clay in varying percentages, and compacted to the maximum dry density at the optimum moisture content. The results indicate that with a fiber length of 10 mm and content of 1.0%, sisal fiber-reinforced silty clay is 20% stronger than nonreinforced silty clay. The fiber-reinforced silty clay exhibited crack fracture and surface shear fracture failure modes, implying that sisal fiber is a good earth reinforcement material with potential applications in civil engineering, dam foundation, roadbed engineering, and ground treatment.

Engineered analogues of cement/clay interactions in the Tournemire experimental platform (France): a coupled mineralogical and geochemical approach to track tiny disturbances

International Nuclear Information System (INIS)

Techer, Isabelle; Michel, Pauline; Tinseau, Elisabeth; Devol-Brown, Isabelle; Bartier, Daniele; Boulvais, Philippe; Suchorski, Krzysztof

2012-01-01

A scientific program has been especially established to better understand the high-pH fluids / clay interactions through a mineralogical and geochemical study of three engineered analogues available by means of the IRSN Tournemire experimental platform. This platform, located in Aveyron (France), is based on a tunnel, excavated between 1882 and 1886 through Domerian marls and Toarcian argillites, and is dedicated since 1990 to multidisciplinary research programs. Different contexts presenting the argillite formation in contact with a cementitious material are encountered and are linked to its historical construction and scientific evolution. These rare examples of cement / clay contacts maintained over time scales ranging from a few years to a hundred of years are studied as engineered analogues of a deep geological storage. This approach is moreover completed by experiments (diffusion and advection) performed in laboratory over shorter time and smaller space scales in order to discriminate and control the major parameters involved in such interactions (details are given in another paper). This paper presents the scientific program developed on the three engineered analogues: tunnel walls recovered by lime after excavation; four concreted exploration boreholes; two experimental research galleries excavated in 2003

Evaluation of the properties of tyre pyrolysis oils obtained in a conical spouted bed reactor

International Nuclear Information System (INIS)

Alvarez, J.; Lopez, G.; Amutio, M.; Mkhize, N.M.; Danon, B.; Gryp, P. van der; Görgens, J.F.; Bilbao, J.; Olazar, M.

2017-01-01

Waste truck tyre valorization by fast pyrolysis has been performed in a conical spouted bed reactor in the 425–575 °C range. The tyre pyrolysis oil (TPO) yield was found to decrease with increasing temperature whilst the yield of gas increased. The effect of temperature on TPO properties has been studied in order to establish the best possible valorization route. FTIR and chromatographic analysis revealed the presence of some undesired compounds with sulphur, nitrogen or oxygen functionalities (benzotiatholes, nitriles and carboxylic acids amongst others) and an increase of TPO aromaticity with increasing temperature. The carbon and sulphur content and the heating value of the TPO increased with temperature. The simulated distillation showed that approximately 70% of the TPOs produced at 425 and 475 °C correspond to diesel range, whereas that TPO obtained at 575 °C is between diesel and gasoline range. The properties of the TPOs evidenced their potential to substitute conventional fuels. However, some of them need to be improved, i.e., by reduction of the sulphur, nitrogen and aromatic content. Additionally, the TPO obtained at 425 and 475 °C could be an important source of limonene and that at 575 °C of xylenes, although current removal methods present some limitations. - Highlights: • The conical spouted bed reactor is suitable for truck tyre fast pyrolysis. • The highest oil yields are attained between 425 and 475 °C (≈58 wt %). • Tyre oil is a mixture of water, aromatic, aliphatic and heteroaromatic compounds. • Limonene is the major compound with a maximum yield of 13.30 wt % at 475 °C. • 425 and 475 °C oils share similarities with diesel and 575 °C one with gasoline.

An optimal pole-matching observer design for estimating tyre-road friction force

Science.gov (United States)

Faraji, Mohammad; Johari Majd, Vahid; Saghafi, Behrooz; Sojoodi, Mahdi

2010-10-01

In this paper, considering the dynamical model of tyre-road contacts, we design a nonlinear observer for the on-line estimation of tyre-road friction force using the average lumped LuGre model without any simplification. The design is the extension of a previously offered observer to allow a muchmore realistic estimation by considering the effect of the rolling resistance and a term related to the relative velocity in the observer. Our aim is not to introduce a new friction model, but to present a more accurate nonlinear observer for the assumed model. We derive linear matrix equality conditions to obtain an observer gain with minimum pole mismatch for the desired observer error dynamic system. We prove the convergence of the observer for the non-simplified model. Finally, we compare the performance of the proposed observer with that of the previously mentioned nonlinear observer, which shows significant improvement in the accuracy of estimation.

Wear estimation of the wheel tyre in different service conditions

Directory of Open Access Journals (Sweden)

Henryk BĄKOWSKI

2014-06-01

Full Text Available In this article presented the results of fatigue strength test aluminium alloys using in car industry. Demonstrated distributions and values of stresses the wheel tyre made of aluminium alloys by means of FEM. In fatigue test used special machine, which can allow to determine Wohler diagram. In this way to determine the allowable stresses values in which do not occurring the damages.

A novel vehicle dynamics stability control algorithm based on the hierarchical strategy with constrain of nonlinear tyre forces

Science.gov (United States)

Li, Liang; Jia, Gang; Chen, Jie; Zhu, Hongjun; Cao, Dongpu; Song, Jian

2015-08-01

Direct yaw moment control (DYC), which differentially brakes the wheels to produce a yaw moment for the vehicle stability in a steering process, is an important part of electric stability control system. In this field, most control methods utilise the active brake pressure with a feedback controller to adjust the braked wheel. However, the method might lead to a control delay or overshoot because of the lack of a quantitative project relationship between target values from the upper stability controller to the lower pressure controller. Meanwhile, the stability controller usually ignores the implementing ability of the tyre forces, which might be restrained by the combined-slip dynamics of the tyre. Therefore, a novel control algorithm of DYC based on the hierarchical control strategy is brought forward in this paper. As for the upper controller, a correctional linear quadratic regulator, which not only contains feedback control but also contains feed forward control, is introduced to deduce the object of the stability yaw moment in order to guarantee the yaw rate and side-slip angle stability. As for the medium and lower controller, the quantitative relationship between the vehicle stability object and the target tyre forces of controlled wheels is proposed to achieve smooth control performance based on a combined-slip tyre model. The simulations with the hardware-in-the-loop platform validate that the proposed algorithm can improve the stability of the vehicle effectively.

Law of nonlinear flow in saturated clays and radial consolidation

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

It was derived that micro-scale amount level of average pore radius of clay changed from 0.01 to 0.1 micron by an equivalent concept of flow in porous media. There is good agreement between the derived results and test ones. Results of experiments show that flow in micro-scale pore of saturated clays follows law of nonlinear flow. Theoretical analyses demonstrate that an interaction of solid-liquid interfaces varies inversely with permeability or porous radius. The interaction is an important reason why nonlinear flow in saturated clays occurs. An exact mathematical model was presented for nonlinear flow in micro-scale pore of saturated clays. Dimension and physical meanings of parameters of it are definite. A new law of nonlinear flow in saturated clays was established. It can describe characteristics of flow curve of the whole process of the nonlinear flow from low hydraulic gradient to high one. Darcy law is a special case of the new law. A mathematical model was presented for consolidation of nonlinear flow in radius direction in saturated clays with constant rate based on the new law of nonlinear flow. Equations of average mass conservation and moving boundary, and formula of excess pore pressure distribution and average degree of consolidation for nonlinear flow in saturated clay were derived by using an idea of viscous boundary layer, a method of steady state in stead of transient state and a method of integral of an equation. Laws of excess pore pressure distribution and changes of average degree of consolidation with time were obtained. Results show that velocity of moving boundary decreases because of the nonlinear flow in saturated clay. The results can provide geology engineering and geotechnical engineering of saturated clay with new scientific bases. Calculations of average degree of consolidation of the Darcy flow are a special case of that of the nonlinear flow.

The waste tyre problem in South Africa: An analysis of the REDISA plan

CSIR Research Space (South Africa)

Nkosi, N

2013-04-01

Full Text Available problem only but has the potential to contribute to job creation, capacity building, establishment of small businesses as well as research and development of new and innovative waste tyre utilization techniques. The Plan is seen as the only viable approach...

Geotechnical studies of Jaitapur marine clay

Digital Repository Service at National Institute of Oceanography (India)

Bhat, S.T.; Nayak, B.U.

characterisEd. by high water content and high Atterberg limits. Undrained shear strength varied from 1.8 to 6 KPa. These were moderately sensitive clays. Carbonate content which varied from 3 to 27%, was found to influence engineering properties of the soil...

Predicted tyre-soil interface area and vertical stress distribution based on loading characteristics

DEFF Research Database (Denmark)

Schjønning, Per; Stettler, M.; Keller, Thomas

2015-01-01

The upper boundary condition for all models simulating stress patterns throughout the soil profile is the stress distribution at the tyre–soil interface. The so-called FRIDA model (Schjønning et al., 2008. Biosyst. Eng. 99, 119–133) treats the contact area as a superellipse and has been shown...... of the actual to recommended inflation pressure ratio. We found that VT and Kr accounted for nearly all variation in the data with respect to the contact area. The contact area width was accurately described by a combination of tyre width and Kr, while the superellipse squareness parameter, n, diminished...... slightly with increasing Kr. Estimated values of the contact area length related to observed data with a standard deviation of about 0.06 m. A difference between traction and implement tyres called for separate prediction equations, especially for the contact area. The FRIDA parameters α and β, reflecting...

Clay content evaluation in soils through GPR signal processing

Science.gov (United States)

Tosti, Fabio; Patriarca, Claudio; Slob, Evert; Benedetto, Andrea; Lambot, Sébastien

2013-10-01

The mechanical behavior of soils is partly affected by their clay content, which arises some important issues in many fields of employment, such as civil and environmental engineering, geology, and agriculture. This work focuses on pavement engineering, although the method applies to other fields of interest. Clay content in bearing courses of road pavement frequently causes damages and defects (e.g., cracks, deformations, and ruts). Therefore, the road safety and operability decreases, directly affecting the increase of expected accidents. In this study, different ground-penetrating radar (GPR) methods and techniques were used to non-destructively investigate the clay content in sub-asphalt compacted soils. Experimental layout provided the use of typical road materials, employed for road bearing courses construction. Three types of soils classified by the American Association of State Highway and Transportation Officials (AASHTO) as A1, A2, and A3 were used and adequately compacted in electrically and hydraulically isolated test boxes. Percentages of bentonite clay were gradually added, ranging from 2% to 25% by weight. Analyses were carried out for each clay content using two different GPR instruments. A pulse radar with ground-coupled antennae at 500 MHz centre frequency and a vector network analyzer spanning the 1-3 GHz frequency range were used. Signals were processed in both time and frequency domains, and the consistency of results was validated by the Rayleigh scattering method, the full-waveform inversion, and the signal picking techniques. Promising results were obtained for the detection of clay content affecting the bearing capacity of sub-asphalt layers.

CTAB as a soft template for modified clay as filler in active packaging

Directory of Open Access Journals (Sweden)

Kajonpop Rittirong

2015-06-01

Full Text Available The role of modified clay has been employed in many areas of engineering research. Structure of clay was mainly focused on alumino-silicate layer and its form was presented as pillar layer. It composed of many ion exchanges inside. In industry, in order to use clay with higher efficiency, modification on surface and porosity has been developed. CTAB, one of the most effective cationic surfactant, was employed to modify the surface and porosity of clay.

Recycling of scrap tyres

International Nuclear Information System (INIS)

Jana, G.K.; Das, C.K.

2005-01-01

De-vulcanization of rubber waste posses a challenging economical, environmental and social problem. In the present study, we propose a new de vulcanization process to reuse the rubber waste called mechan-chemical process (MCP), where the waste were de-vulcanized through the application of mechanical shearing, heat (110 degree C) and de-vulcanizing agent (Di-benzyl disulfide). A new look into the de-vulcanization mechanism and the influence of de-vulcanizing agent on mechanical properties of re-vulcanized rubber was presented. One of the most interesting observations is that the retention of tensile strength of re-vulcanized rubber with respect to original tyre is 35.1% and 75.6%, when de-vulcanized in absence and in presence of disulfide respectively. The formation of extra cross-link bond in re-vulcanized rubber containing disulfide was confirmed from cross-link density data and TGA result. DMA analysis revealed that the storage modulus increased for re vulcanized rubber containing disulfide. The SEM was considered in order to study the failure mechanism and homogeneity as affected by the de vulcanization process

Clay-cement suspensions - rheological and functional properties

Science.gov (United States)

Wojcik, L.; Izak, P.; Mastalska-Poplawska, J.; Gajek, M.

2017-01-01

The piping erosion in soil is highly unexpected in civil engineering. Elimination of such damages is difficult, expensive and time-consuming. One of the possibility is the grouting method. This method is still developed into direction of process automation as well as other useful properties of suspensions. Main way of modernization of the grouting method is connected it with rheology of injection and eventuality of fitting them to specific problems conditions. Very popular and useful became binders based on modified clays (clay-cement suspensions). Important principle of efficiency of the grouting method is using of time-dependent pseudothixotropic properties of the clay-cement suspensions. The pseudo-rheounstability aspect of the suspensions properties should be dedicated and fitted to dynamic changes of soil conditions destructions. Whole process of the modification of the suspension rheology is stimulated by the specific agents. This article contains a description of practical aspects of the rheological parameters managing of the clay-cement suspensions, dedicated to the building damages, hydrotechnic constructions etc.

Combined removal of a BTEX, TCE, and cis-DCE mixture using Pseudomonas sp. immobilized on scrap tyres.

Science.gov (United States)

Lu, Qihong; de Toledo, Renata Alves; Xie, Fei; Li, Junhui; Shim, Hojae

2015-09-01

The simultaneous aerobic removal of a mixture of benzene, toluene, ethylbenzene, and o,m,p-xylene (BTEX); cis-dichloroethylene (cis-DCE); and trichloroethylene (TCE) from the artificially contaminated water using an indigenous bacterial isolate identified as Pseudomonas plecoglossicida immobilized on waste scrap tyres was investigated. Suspended and immobilized conditions were compared for the removal of these volatile organic compounds. For the immobilized system, toluene, benzene, and ethylbenzene were completely removed, while the highest removal efficiencies of 99.0 ± 0.1, 96.8 ± 0.3, 73.6 ± 2.5, and 61.6 ± 0.9% were obtained for o-xylene, m,p-xylene, TCE, and cis-DCE, respectively. The sorption kinetics of contaminants towards tyre surface was also evaluated, and the sorption capacity generally followed the order of toluene > benzene > m,p-xylene > o-xylene > ethylbenzene > TCE > cis-DCE. Scrap tyres showed a good capability for the simultaneous sorption and bioremoval of BTEX/cis-DCE/TCE mixture, implying a promising waste material for the removal of contaminant mixture from industrial wastewater or contaminated groundwater.

Experimental investigations of tyre-road interactions during braking; Experimentelle Untersuchungen zur Interaktion zwischen Pkw-Reifen und Fahrbahn beim Bremsen

Energy Technology Data Exchange (ETDEWEB)

Chunyang Xie

2002-07-01

Tyre-road interactions during braking were investigated experimentally. The measurements were found to be highly accurate. In the first stage, the braking force is enhanced by elastic deformation of the profile elements at the onset of tyre contact. In case of high slip or a high sliding velocity, frictional vibration of the tyre section in contact with the road may occur, which is enhanced by the reduction of braking pressure in case of automatic brake control. The eigenfreequency of the frictional vibration also depends on the road texture and friction coefficient. The measured movements of the profile elements provide a good explanation of the causes of tyre noise. [German] In der Dissertation wurde die Interaktion Reifen/Fahrbahn beim Bremsen experimentell untersucht. Die Messungen zeigen, dass die mit dem neuen Reifensensor erfassten Profilelementverformungen den Reibungszustand zwischen Reifen und Fahrbahn gut widerspiegeln. Die Bremskraft wird zunaechst durch die elastischen Verformungen der Profilelemente am Anfang des Reifenlatsches wesentlich aufgebaut. Beim hohen Bremsschlupf bzw. der hohen Gleitgeschwindigkeit kann die Reibungsschwingung des Laufstreifens des Reifens auftreten. Der Bremsdruckabbau der ABS-Regelung beguenstigt die Entstehung dieser Reibungsschwingung. Die Eigenfrequenz der Reibungsschwingung ist auch abhaengig von der Fahrbahntextur und dem Reibwert. Die aus den Signalen des Profilrillensensors berechneten Beschleunigungen der Profilelemente zeigen deutlich den Aufschlag beim Einlauf des Reifens und das Ausschnappen beim Auslauf. Durch die gemessenen Bewegungen der Profilelemente laesst sich die Entstehung des Reifengeraeusches in einigen Frequenzbereichen gut erklaeren. (orig.)

Measuring Tyre Rolling Noise at the Contact Patch

Science.gov (United States)

Kozak, P.; Matuszkova, R.; Radimsky, M.; Kudrna, J.

2017-06-01

This paper deals with noise generated by road traffic. A focus is concentrated solely on one of its sources related to tyre/road interaction referred as rolling noise. The paper states brief overview of various approaches and methods used to measure this particular source of road traffic noise. On the basis of literature reviews, a unique device has been designed. Development of the measuring device and possibilities of its usage are described in detail in this paper. Obtained results of noise measurements can then be used to design measures that increase safety and a lead to better comfort on the road.

Heteroaggregation of titanium dioxide nanoparticles with natural clay colloids.

Science.gov (United States)

Labille, Jérôme; Harns, Carrie; Bottero, Jean-Yves; Brant, Jonathan

2015-06-02

To better understand and predict the fate of engineered nanoparticles in the water column, we assessed the heteroaggregation of TiO2 nanoparticles with a smectite clay as analogues for natural colloids. Heteroaggregation was evaluated as a function of water salinity (10(-3) and 10(-1) M NaCl), pH (5 and 8), and selected nanoparticle concentration (0-4 mg/L). Time-resolved laser diffraction was used, coupled to an aggregation model, to identify the key mechanisms and variables that drive the heteroaggregation of the nanoparticles with colloids. Our data show that, at a relevant concentration, nanoparticle behavior is mainly driven by heteroaggregation with colloids, while homoaggregation remains negligible. The affinity of TiO2 nanoparticles for clay is driven by electrostatic interactions. Opposite surface charges and/or high ionic strength favored the formation of primary heteroaggregates via the attachment of nanoparticles to the clay. The initial shape and dispersion state of the clay as well as the nanoparticle/clay concentration ratio also affected the nature of the heteroaggregation mechanism. With dispersed clay platelets (10(-3) M NaCl), secondary heteroaggregation driven by bridging nanoparticles occurred at a nanoparticle/clay number ratio of greater than 0.5. In 10(-1) M NaCl, the clay was preaggregated into larger and more spherical units. This favored secondary heteroaggregation at lower nanoparticle concentration that correlated to the nanoparticle/clay surface area ratio. In this latter case, a nanoparticle to clay sticking efficiency could be determined.

Performance of sand and shredded rubber tire mixture as a natural base isolator for earthquake protection

Science.gov (United States)

Bandyopadhyay, Srijit; Sengupta, Aniruddha; Reddy, G. R.

2015-12-01

The performance of a well-designed layer of sand, and composites like layer of sand mixed with shredded rubber tire (RSM) as low cost base isolators, is studied in shake table tests in the laboratory. The building foundation is modeled by a 200 mm by 200 mm and 40 mm thick rigid plexi-glass block. The block is placed in the middle of a 1m by 1m tank filled with sand. The selected base isolator is placed between the block and the sand foundation. Accelerometers are placed on top of the footing and foundation sand layer. The displacement of the footing is also measured by LVDT. The whole setup is mounted on a shake table and subjected to sinusoidal motions with varying amplitude and frequency. Sand is found to be effective only at very high amplitude (> 0.65 g) of motions. The performance of a composite consisting of sand and 50% shredded rubber tire placed under the footing is found to be most promising as a low-cost effective base isolator.

Factors Affecting the Adsorption of Trivalent Chromium Ions by Activated Carbon Prepared from Waste Rubber Tyres

Directory of Open Access Journals (Sweden)

Sylvia E. Benjamin

2017-08-01

Full Text Available Economic gains are generally the outcome of industrialization and consequently urbanization. However, positive fiscal index generates a negative impact on natural environment sources heaving pollutant burden on soil, air and water. Industries throw tones of contaminated water into soil and water bodies without proper treatment and create a potential threat for both living and non-living species. Chromium in trivalent state (Cr3+ is added in water bodies and soil through waste water from tanneries, cooling water systems, chemical and pulp and paper industries. The present research work aims at the preparation of an inexpensive activated carbon prepared from non- degradable waste scrap rubber tyres. The carbon produced from scrap rubber tyres was activated by 5% solution of BaCl2 and 0.4 N solution of HCl and verified by ethylene blue solution. The adsorption capacity of the Tyre activated carbon (TAC was investigated for different parameters i.e., initial chromium (III ion concentration, activated carbon dosage, contact/ stirring time and pH. The adsorption capacity of TAC depends on the initial metal ion concentration and the TAC dose. pH of the chromium solution effects the adsorption capacity of TAC due to the formation of tetra hydroxochromate(III complexes,. The results show that TAC offers a cost effective reclamation process for the removal of Cr3+ from effluent waters.

Comparative Analysis on Chemical Composition of Bentonite Clays ...

African Journals Online (AJOL)

2017-09-12

Sep 12, 2017 ... Comparative Analysis on Chemical Composition of Bentonite Clays. Obtained from Ashaka and ... versatile material for geotechnical engineering and as well as their demand for ..... A PhD thesis submitted to the Chemical ...

Heterogeneous reactions of dioctahedral smectites in illite-smectite and kaolinite-smectite mixed-layers: applications to clay materials for engineered barriers

International Nuclear Information System (INIS)

Meunier, A.; Proust, D.; Beaufort, D.; Lajudie, A.; Petit, J.-C.

1992-01-01

The clay materials selected for use in the engineered barriers of the French nuclear waste isolation programme are mainly composed of dioctahedral smectite, either bentonite of Wyoming type or kaolinite-smectites most often consist of randomly stacked layers with low and high charges. In the case of the Wyoming-type bentonite, these two differently charged layers do not react in the same way when subjected to hydrothermal alteration. Overall, the low-charge smectite layers react to form high-charge smectite layers + quartz + kaolinite. Then, fixing K ions, the high-charge smectite layers are transformed into illite-smectite mixed-layers (I/S) when the temperature conditions increase. A symmetrical process is observed in natural or experimental hydrothermal conditions when the high-charge smectite layers of I/S minerals react with quartz and/or kaolinite to produce low-charge smectite layers. The chemical properties of the bentonite-engineered barriers clearly depend on the low charge/high charge smectite layer proportion, which is in turn controlled by the temperature-dependent reactions in the vicinity of the waste disposal. Although there are fewer published data on the kaolinite-smectite mixed-layered minerals (K/S), a similar low charge-high charge reaction appears to affect their smectite component. The experimental alteration of K/S leads to the formation of a low-charge beidellite with an increase in the cation-exchange capacity and in the expandability of the clay material. Thus, the properties of the engineered barrier seems to be improved after hydrothermal alteration. (Author)

Incorporating moving dynamic tyre loads in pavement design and analysis

CSIR Research Space (South Africa)

Steyn, WJvdM

2000-07-01

Full Text Available at the University of Pretoria. 4 REAL LIFE TYRE LOADS Characterisation Pavement loading has been shown by various authors to be a dynamic (time-dependent) phenomenon (Divine, 1997; Cebon, 1999). A pavement experiences a vehicle as a moving, time-varying set... frequencies. Body bounce generally dominates the dynamic loading, and is mainly caused by the response of the sprung mass of the vehicle to the pavement roughness. Axle hop becomes more significant at higher vehicle speeds and higher pavement roughnesses...

Thermal Stability of Clay's Galleries in Polypropylene - Clay (montmorillonite Nanocomposites using Polypropylene-gMaleic Anhydride as Compatibilizer

Directory of Open Access Journals (Sweden)

Sotya Astutiningsih

2010-10-01

Full Text Available Superior properties of food packaging can be achieved using nanocomposite technology. However, fabrication of this materials are complex and expensive. Long term objectives of this research is the synthesis of low cost polypropylene clay nanocomposites (PPCN via a short-cut method known as ‘cascade engineering’. Cascade engineering principle in PPCN fabrication is performed by using compatibilizer (to enable the mixing of PP and clay masterbatch, and PPCN in one pot process using melt mixer. This paper present the experimental results using small-angle x-ray diffraction (XRD on the thermal stability of the PPCN. Results from the XRD analysis showed that the clay was intercalated, however no significant changes were observed as a result of variation in mixing time. XRD patterns of the annealed PPCN showed reduction of MMT’s gallery (deintercalation These phenomenon was probably caused by insufficient bonding and lack of compatibility between PP-g-MA and MMT.

A multibody motorcycle model with rigid-ring tyres: formulation and validation

Science.gov (United States)

Leonelli, Luca; Mancinelli, Nicolò

2015-06-01

The aim of this paper is the development and validation of a three-dimensional multibody motorcycle model including a rigid-ring tyre model, taking into account both the slopes and elevation of the road surface. In order to achieve accurate assessment of ride and handling performances of a road racing motorcycle, a tyre model capable of reproducing the dynamic response to actual road excitation is required. While a number of vehicle models with such feature are available for car application, the extension to the motorcycle modelling has not been addressed yet. To do so, a novel parametrisation for the general motorcycle kinematics is proposed, using a mixed reference point and relative coordinates approach. The resulting description, developed in terms of dependent coordinates, makes it possible to include the rigid-ring kinematics as well as road elevation and slopes, without affecting computational efficiency. The equations of motion for the whole multibody system are derived symbolically and the constraint equations arising from the dependent coordinate formulation are handled using the position and velocity vector projection technique. The resulting system of equations is integrated in time domain using a standard ordinary differential equation (ODE) algorithm. Finally, the model is validated with respect to experimentally measured data in both time and frequency domains.

Ozone decay in chemical reactor for ozone-dynamical disintegration of used tyres

International Nuclear Information System (INIS)

Golota, V.I.; Manuilenko, O.V.; Taran, G.V.; Dotsenko, Yu.V.; Pismenetskii, A.S.; Zamuriev, A.A.; Benitskaja, V.A.

2011-01-01

The ozone decay kinetics in the chemical reactor intended for used tyres disintegration is investigated experimentally and theoretically. Ozone was synthesized in barrierless ozonizers based on the streamer discharge. The chemical reactor for tyres disintegration in the ozone-air environment represents the cylindrical chamber, which feeds from the ozonizer by ozone-air mixture with the specified rate of volume flow, and with known ozone concentration. The output of the used mixture, which rate of volume flow is also known, is carried out through the ozone destructor. As a result of ozone decay in the volume and on the reactor walls, and output of the used mixture from the reactor, the ozone concentration in the reactor depends from time. In the paper, the analytical expression for dependence of ozone concentration in the reactor from time and from the parameters of a problem such as the volumetric feed rate, ozone concentration on the input in the reactor, volume flow rate of the used mixture, the volume of the reactor and the area of its internal surface is obtained. It is shown that experimental results coincide with good accuracy with analytical ones.

Clay membrane made of natural high plasticity clay

DEFF Research Database (Denmark)

Foged, Niels; Baumann, Jens

1998-01-01

Leachate containment in Denmark has through years been regulated by the DIF Recommendation for Sanitary Landfill Liners (DS/R 466). It states natural clay deposits may be used for membrane material provided the membrane and drainage system may contain at least 95% of all leachate created throughout...... ion transport as well as diffusion.Clay prospection for clays rich in smectite has revealed large deposits of Tertiary clay of very high plasticity in the area around Rødbyhavn on the Danish island Lolland. The natural clay contains 60 to 75% smectite, dominantly as a sodium-type. The clay material...... has been evaluated using standardised methods related to mineralogy, classification, compaction and permeability, and initial studies of diffusion properties have been carried out. Furthermore, at a test site the construction methods for establishing a 0.15 to 0.3m thick clay membrane have been tested...

Clay membrane made of natural high plasticity clay:

DEFF Research Database (Denmark)

Foged, Niels; Baumann, Jens

1999-01-01

Leachate containment in Denmark has throughout the years been regulated by the DIF Recommendation for Sanitary Landfill Liners (DS/R4669. It states that natural clay deposits may be used as membrane material provided the membrane and drainage system contains at least 95% of all leachate created...... into account advective ion transport as well as diffusion. Clay prospecting for clays rich in smectite has revealed large deposits of Tertiary clay of very high plasticity in the area around Rødbyhavn on the Danish island of Lolland. The natural clay contains 60-75% smectite, dominantly as a sodium......-type. The clay material has been evaluated using the standardized methods related to mineralogy, classification, compaction and permeability, and initial studies of diffusion properties have been carried out. Furthermore, at a test site the construction methods for establishing a 0.15-0.3 m thick clay membrane...

Thermal volume changes in clays and clay-stones

International Nuclear Information System (INIS)

Delage, P.; Sulem, J.; Mohajerani, M.; Tang, A.M.; Monfared, M.

2012-01-01

Document available in extended abstract form only. The disposal of high activity exothermic radioactive waste at great depth in clay host rocks will induce a temperature elevation that has been investigated in various underground research laboratories in Belgium, France and Switzerland through in-situ tests. Thermal effects are better known in clays (in particular Boom clay) than in clay-stone (e.g. Opalinus clay and Callovo-Oxfordian clay-stone). In terms of volume changes, Figure 1 confirms the findings of Hueckel and Baldi (1990) that volume changes depend on the over-consolidation ratio (OCR) of the clay. In drained conditions, normally consolidated clays exhibit plastic contraction when heated, whereas over-consolidated clay exhibit elastic dilation. The nature of thermal volume changes in heated clays obviously has a significant effect on thermally induced pore pressures, when drainage is not instantaneous like what occurs in-situ. Compared to clays, the thermal volume change behaviour of clay-stones is less well known than that of clays. clay-stone are a priori suspected to behave like over-consolidated clays. In this paper, a comparison of recent results obtained in the laboratory on the drained thermal volume changes of clay-stones is presented and discussed. It is difficult to run drained mechanical tests in clay-stones like the Opalinus clay and the Callovo-Oxfordian clay-stone because of their quite low permeability (10 -12 - 10 -13 m/s). This also holds true for thermal tests. Due to the significant difference in thermal expansion coefficient between minerals and water, it is necessary to adopt very slow heating rate (0.5 - 1 C/h) to avoid any thermal pressurization. To do so, a new hollow cylinder apparatus (100 mm external diameter, 60 mm internal diameter) with lateral drainages reducing the drainage length to half the sample thickness (10 mm) has been developed (Monfared et al. 2011). The results of a drained cyclic thermal test carried out on

California Bearing Ratio (CBR) test on stabilization of clay with lime addition

Science.gov (United States)

Hastuty, I. P.; Roesyanto; Limbong, M. N.; Oberlyn, S. J.

2018-02-01

Clay is a type of soil with particles of certain minerals giving plastic properties when mixed with water. Soil has an important role in a construction, besides as a building material in a wide variety of civil engineering works, soil is also used as supporting foundation of the building. Basic properties of clay are rock-solid in dry and plastic with medium water content. In high water content, clay becomes sticky like (cohesive) and soften. Therefore, clay stabilization is necessary to repair soil’s mechanical properties. In this research, lime is use as a stabilizer that contains the Ca+ element to bond bigger particles. Lime used is slaked lime Ca(OH)2. Clay used has liquid limitation (LL) value of 47.33%, plasticity index of 29.88% and CBR value 6.29. The results explain about 10% lime mixture variation gives the optimum stabilized clay with CBR value of 8.75%.

Corrosion behaviour of carbon steel in the Tournemire clay

International Nuclear Information System (INIS)

Foct, F.; Dridi, W.; Cabrera, J.; Savoye, S.

2004-01-01

Carbon steels are possible materials for the fabrication of nuclear waste containers for long term geological disposal in argillaceous environments. Experimental studies of the corrosion behaviour of such materials has been conducted in various conditions. Concerning the numerous laboratory experiments, these conditions (water and clay mixture or compacted clay) mainly concern the bentonite clay that would be used for the engineered barrier. On the opposite, only few in-situ experiments has been conducted directly in the local clay of the repository site (such as Boom clay, etc.). In order to better estimate the corrosion behaviour of carbon steels in natural clay site conditions, an experimental study has been conducted jointly by EDF and IRSN in the argillaceous French site of Tournemire. In this study, A42 carbon steel specimens have been exposed in 3 different zones of the Tournemire clay formation. The first type of environmental conditions concerns a zone where the clay has not been affected by the excavation (EDZ) of the main tunnel neither by the main fracture zone of the clay formation. The second and third ones are located in the EDZ of the tunnel. In the second zone, an additional aerated water flows from the tunnel, whereas it does not in the third place. Some carbon steel specimens have been extracted after several years of exposure to these conditions. The average corrosion rate has been measured by the weight loss technique and the pitting corrosion depth has been evaluated under an optical microscope. Corrosion products have also been characterised by scanning electron microscopy and X-ray diffraction technique. Results are then discussed regarding the surrounding environmental conditions. Calculations of the oxygen transport from the tunnel through the clay and of the clay re-saturation can explain, in a first approach, the corrosion behaviour of the carbon steel in the different tested zones. (authors)

Validation of water sorption-based clay prediction models for calcareous soils

DEFF Research Database (Denmark)

Arthur, Emmanuel; Razzaghi, Fatemeh; Moosavi, Ali

2017-01-01

on prediction accuracy. The soils had clay content ranging from 9 to 61% and CaCO3 from 24 to 97%. The three water sorption models considered showed a reasonably fair prediction of the clay content from water sorption at 28% relative humidity (RMSE and ME values ranging from 10.6 to 12.1 and −8.1 to −4......Soil particle size distribution (PSD), particularly the active clay fraction, mediates soil engineering, agronomic and environmental functions. The tedious and costly nature of traditional methods of determining PSD prompted the development of water sorption-based models for determining the clay...... fraction. The applicability of such models to semi-arid soils with significant amounts of calcium carbonate and/or gypsum is unknown. The objective of this study was to validate three water sorption-based clay prediction models for 30 calcareous soils from Iran and identify the effect of CaCO3...

Clay Play

Science.gov (United States)

Rogers, Liz; Steffan, Dana

2009-01-01

This article describes how to use clay as a potential material for young children to explore. As teachers, the authors find that their dialogue about the potential of clay as a learning medium raises many questions: (1) What makes clay so enticing? (2) Why are teachers noticing different play and conversation around the clay table as compared to…

TRIP-ID: A tool for a smart and interactive identification of Magic Formula tyre model parameters from experimental data acquired on track or test rig

Science.gov (United States)

Farroni, Flavio; Lamberti, Raffaele; Mancinelli, Nicolò; Timpone, Francesco

2018-03-01

Tyres play a key role in ground vehicles' dynamics because they are responsible for traction, braking and cornering. A proper tyre-road interaction model is essential for a useful and reliable vehicle dynamics model. In the last two decades Pacejka's Magic Formula (MF) has become a standard in simulation field. This paper presents a Tool, called TRIP-ID (Tyre Road Interaction Parameters IDentification), developed to characterize and to identify with a high grade of accuracy and reliability MF micro-parameters from experimental data deriving from telemetry or from test rig. The tool guides interactively the user through the identification process on the basis of strong diagnostic considerations about the experimental data made evident by the tool itself. A motorsport application of the tool is shown as a case study.

Effects of the stress field induced by a running tyre on the soil pore system

DEFF Research Database (Denmark)

Berisso, Feto Esimo; Schjønning, Per; Lamandé, Mathieu

2013-01-01

state in the soil profile beneath the harvester tyre was calculated using the SoilFlex model. Pore continuity index (N) and blocked air-filled porosity (εb) were estimated from the relationship between ka and air-filled porosity (εa) for a range of matric potentials. Calculated and measured stresses...... repeated wheelings were performed by a forage harvester (wheel load 6100 kg; tyre width 80 cm). Mean normal and horizontal stresses were measured with Bolling probes (at 10, 20 and 40 cm depth) and load cells (at 40, 50, 60 cm lateral distance from the centreline of the wheel rut at 10, 30 and 50 cm depth......), respectively. Intact soil cores of 100 cm3 sampled at 10, 30 and 50 cm depth in a soil transcet running from the centreline of the wheel rut to the unwheeled part of the field were used for measurements of water retention and air permeability (ka) at −30, −100 and −300 hPa matric potential. The complete stress...

Ball clay

Science.gov (United States)

Virta, R.L.

2001-01-01

Part of the 2000 annual review of the industrial minerals sector. A general overview of the ball clay industry is provided. In 2000, sales of ball clay reached record levels, with sanitary ware and tile applications accounting for the largest sales. Ball clay production, consumption, prices, foreign trade, and industry news are summarized. The outlook for the ball clay industry is also outlined.

Influence of clay mineralogy on clay based ceramic products

International Nuclear Information System (INIS)

Radzali Othman; Tuan Besar Tuan Sarif; Zainal Arifin Ahmad; Ahmad Fauzi Mohd Noor; Abu Bakar Aramjat

1996-01-01

Clay-based ceramic products can either be produced directly from a suitable clay source without the need further addition or such products can be produced from a ceramic body formulated by additions of other raw materials such as feldspar and silica sand. In either case, the mineralogical make-up of the clay component plays a dominating role in the fabrication and properties of the ceramic product. This study was sparked off by a peculiar result observed in one of five local ball clay samples that were used to reformulate a ceramic body. Initial characterisation tests conducted on the clays indicated that these clays can be classified as kaolinitic. However, one of these clays produced a ceramic body that is distinctively different in terms of whiteness, smoothness and density as compared to the other four clays. Careful re-examination of other characterisation data, such as particle size distribution and chemical analysis, failed to offer any plausible explanation. Consequently, the mineralogical analysis by x-ray diffraction was repeated by paying meticulous attention to specimen preparation. Diffraction data for the clay with anomalous behaviour indicated the presence of a ∼ 10A peak that diminished when the same specimen was re-tested after heating in an oven at 12O degree C whilst the other four clays only exhibit the characteristic kaolinite (Al sub 2 O sub 3. 2SiO sub 2. 2H sub 2 0) and muscovite peaks at ∼ 7A and ∼ 10A before and after heat treatment. This suggests the presence of the mineral halloysite (A1 sub 2 0 sub 3. 2SiO sub 2.4H sub 2 0) in that particular clay. This difference in mineralogy can be attributed to account for the variations in physical properties of the final product. Consequently, this paper reviews in general the precautionary measures that must be adhered to during any mineralogical investigation of clay minerals or clay-based materials. The common pitfalls during specimen preparation, machine settings and interpretation of

Assessment of the Effectiveness of Clay Soil Covers as Engineered Barriers in Waste Disposal Facilities with Emphasis on Modeling Cracking Behavior

Science.gov (United States)

2008-06-01

standard proctor hammer (ASTM D698), which was dropped a sufficient number of times to achieve the desired dry density ERDC TR-08-7 34 Figure...using a standard proctor hammer to an equivalent dry density as was found in Experiment 1. ERDC TR-08-7 45 Figure 25. Sample container for...ER D C TR -0 8- 7 Assessment of the Effectiveness of Clay Soil Covers as Engineered Barriers in Waste Disposal Facilities with Emphasis

Sequential disinfection of E. coli O157:H7 on shredded lettuce leaves by aqueous chlorine dioxide, ozonated water, and thyme essential oil

Science.gov (United States)

Singh, Nepal; Singh, Rakesh K.; Bhunia, Arun K.; Stroshine, Richard L.; Simon, James E.

2001-03-01

There have been numerous studies on effectiveness of different sanitizers for microbial inactivation. However, results obtained from different studies indicate that microorganism cannot be easily removed from fresh cut vegetables because of puncture and cut surfaces with varying surface topographies. In this study, three step disinfection approach was evaluated for inactivation of E. coli O157:H7 on shredded lettuce leaves. Sequential application of thyme oil, ozonated water, and aqueous chlorine dioxide was evaluated in which thyme oil was applied first followed by ozonated water and aqueous chlorine dioxide. Shredded lettuce leaves inoculated with cocktail culture of E. coli O157:H7 (C7927, EDL 933 and 204 P), were washed with ozonated water (15 mg/l for 10min), aqueous chlorine dioxide (10 mg/l,for 10min) and thyme oil suspension (0.1%, v/v for 5min). Washing of lettuce leaves with ozonated water, chlorine dioxide and thyme oil suspension resulted in 0.44, 1.20, and 1.46 log reduction (log10 cfu/g), respectively. However, the sequential treatment achieved approximately 3.13 log reductions (log10 cfu/g). These results demonstrate the efficacy of sequential treatments in decontaminating shredded lettuce leaves containing E. coli O157:H7.

Effect of concentrated epoxidised natural rubber and silica masterbatch for tyre application

Energy Technology Data Exchange (ETDEWEB)

Azira, A. A., E-mail: azira@lgm.gov.my; Kamal, M. M., E-mail: mazlina@lgm.gov.my [High Value Added Rubber Products and Nanostructured Materials, Stesen Penyelidikan RRIM, LGM 47000 Sungai Buloh, Selangor (Malaysia); Verasamy, D., E-mail: devaraj@lgm.gov.my [Environmental Technology & Sustainability, Technology & Engineering Division, Malaysian Rubber Board, Stesen Penyelidikan RRIM, LGM 47000 Sungai Buloh, Selangor (Malaysia)

2016-07-06

The availability of concentrated epoxidised natural rubber (ENR-LC) has provided a better opportunity for using epoxidised natural rubber (ENR) with silica to reinforce natural rubber for tyre application. ENR-LC mixed directly with silica to rubber by high speed stirrer without using any coupling agent. Some rubber compounds were prepared by mixing a large amount of precipitated amorphous white silica with natural rubber. The silica was prepared in aqueous dispersion and the filler was perfectly dispersed in the ENR-LC. The performance of the composites was evaluated in this work for the viability of ENR-LC/Si in tyre compounding. Compounding was carried out on a two roll mill, where the additives and curing agents was later mixed. Characterization of these composites was performed by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) for dispersion as well as mechanical testing. C-ENR/Si showed efficient as primary reinforcing filler in ENR with regard to modulus and tensile strength, resulting on an increase in the stiffness of the rubbers compared to ENR latex. Overall improvement in the mechanical properties for the ENR-LC over the control crosslinked rubber sample was probably due to synergisms of silica reinforcement and crosslinking of the polymeric matrix phase.

Effect of concentrated epoxidised natural rubber and silica masterbatch for tyre application

International Nuclear Information System (INIS)

Azira, A. A.; Kamal, M. M.; Verasamy, D.

2016-01-01

The availability of concentrated epoxidised natural rubber (ENR-LC) has provided a better opportunity for using epoxidised natural rubber (ENR) with silica to reinforce natural rubber for tyre application. ENR-LC mixed directly with silica to rubber by high speed stirrer without using any coupling agent. Some rubber compounds were prepared by mixing a large amount of precipitated amorphous white silica with natural rubber. The silica was prepared in aqueous dispersion and the filler was perfectly dispersed in the ENR-LC. The performance of the composites was evaluated in this work for the viability of ENR-LC/Si in tyre compounding. Compounding was carried out on a two roll mill, where the additives and curing agents was later mixed. Characterization of these composites was performed by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) for dispersion as well as mechanical testing. C-ENR/Si showed efficient as primary reinforcing filler in ENR with regard to modulus and tensile strength, resulting on an increase in the stiffness of the rubbers compared to ENR latex. Overall improvement in the mechanical properties for the ENR-LC over the control crosslinked rubber sample was probably due to synergisms of silica reinforcement and crosslinking of the polymeric matrix phase.

Scrap tyre recycling process with molten zinc as direct heat transfer and solids separation fluid: A new reactor concept.

Science.gov (United States)

Riedewald, Frank; Goode, Kieran; Sexton, Aidan; Sousa-Gallagher, Maria J

2016-01-01

Every year about 1.5 billion tyres are discarded worldwide representing a large amount of solid waste, but also a largely untapped source of raw materials. The objective of the method was to prove the concept of a novel scrap tyre recycling process which uses molten zinc as the direct heat transfer fluid and, simultaneously, uses this media to separate the solids products (i.e. steel and rCB) in a sink-float separation at an operating temperature of 450-470 °C. This methodology involved: •construction of the laboratory scale batch reactor,•separation of floating rCB from the zinc,•recovery of the steel from the bottom of the reactor following pyrolysis.

Theory of rubber friction and traction properties of car tyres; Theorie der Gummireibung und Traktionseigenschaften von Reifen

Energy Technology Data Exchange (ETDEWEB)

Klueppel, M.; Alshuth, T.; Schuster, R.H. [Deutsches Inst. fuer Kautschuktechnologie e.V., Hannover (Germany)

1998-12-31

ABS braking on dry and wet roads involves different mechanisms of rubber friction on rough surfaces. This improves car safety in terms of higher manoeuvrability and shorter braking lengths especially on wet roads. Current research focuses on optimisation of tyrecontact surface materials with better traction characteristics and lower rolling resistance. Laboratory predictions of the traction properties of tyre faces must be based on fundamental knowledge of the local sliding phenomena in the tyre contact surface and the resulting energy dissipation during ABS braking. This contribution therefore attempts to relate the elementary mechanisms of tyre mechanics in ABS braking processes to theoretical concepts of rubber friction on rough surfaces. [Deutsch] Beim ABS-Bremsen auf trockenen und nassen Strassen werden unterschiedliche Mechanismen der Gummireibung auf rauhen Oberflaechen wirksam. In der Summe bewirkt dies eine hoehere Fahrsicherheit, da neben der Manoevrierfaehigkeit des Autos auch der Bremsweg, vor allem auf nassen Strassen, verkuerzt sein kann. In diesem Zusammenhang wird zur Zeit verstaerkt an einer Optimierung von Laufflaechenmaterialien durch den Einsatz von massgeschneiderten Loesungs-SBR-Typen in Verbindung mit gefaellten Kieselsaeuren gearbeitet, wodurch neben einer Verbesserung der Traktionseigenschaften beim ABS-Bremsen auch eine Verringerung des Rollwiderstandes erreicht wird. Fuer Laborvorhersagen der Traktionseigenschaften von Reifenlaufflaechen ist ein grundlegendes Verstaendnis der lokalen Gleitphaenomene in der Reifenaufstandsflaeche und der damit verbundenen Energiedissipation beim ABS-Bremsen erforderlich. In dieser Arbeit wird deshalb angestrebt, die elementaren Mechanismen der Reifenmechanik beim ABS-Bremsen mit theoretischen Konzepten der Gummireibung auf rauhen Oberflaechen in Verbindung zu bringen. (orig.)

Morphology study of polyamide 6/bentonite clay nanocomposites

International Nuclear Information System (INIS)

Paz, Rene A.; Araujo, Edcleide M.; Melo, Tomas J.A.; Leite, Amanda M.D.; Medeiros, Vanessa Nobrega; Pessan, Luiz A.; Passador, Fabio R.

2011-01-01

Polymer/clay nanocomposites have had much attention in recent years, especially those developed with layered silicates, due to the need for engineering materials more efficient than pure polymers for certain applications. The level of exfoliation of layered silicates in the crystalline structure of polymer matrices has been studied and it has been observed that it affects the behavior of crystalline and therefore the mechanical and physical properties. In this study, polyamide 6 nanocomposites were obtained by the melt intercalation technique, using regional bentonite clay modified with a quaternary ammonium salt in an amount of 3% by weight. XRD and TEM tests showed obtaining nanocomposites with exfoliated structures (author)

A Semi-Empirical Three-Dimensional Model of the Pneumatic Tyre Rolling over Arbitrarily Uneven Road Surfaces

NARCIS (Netherlands)

Schmeitz, A.J.C.

2004-01-01

Nowadays virtual prototyping tools play an important part in the development of vehicles. For studying the dynamics of a vehicle, complex vehicle models are required that are composed of several accurately modelled components. As the tyre constitutes the only contact between the vehicle and the road

Pyrolysis of tyres. Influence of the final temperature of the process on emissions and the calorific value of the products recovered

International Nuclear Information System (INIS)

Diez, C.; Martinez, O.; Calvo, L.F.; Cara, J.; Moran, A.

2004-01-01

A study was made of the pyrolysis of tyre particles, with the aim of determining the possibilities of using the products resulting from the process as fuel. Three final temperatures were used, determined from thermogravimetric data. The design of the experiment was a horizontal oven containing a reactor into which particles of the original tyre were placed. After the process, a solid fraction (char) remained in the reactor, while the gases generated went through a set of scrubbers where most of the condensable fraction (oils) was retained. Finally, once free of this fraction, the gases were collected in glass ampoules. Solid and liquids fractions were subjected to thermogravimetric analyses in order to study their combustibility. The gas fraction was analysed by means of gas chromatography to establish the content of CO, CO 2 , H 2 and hydrocarbons present in the samples (mainly components of gases produced in the pyrolysis process). A special study was made of the sulphur and chlorine content of all the fractions, as the presence of these elements could be problematic if the products are used as fuel. Tyre pyrolysis engenders a solid carbon residue that concentrates sulphur and chorine, with a relatively high calorific value, although not so high as that of the original tyre. The liquid fraction produced by the process has a high calorific value, which rises with the final temperature, up to 40 MJ/kg. The chlorine content of this fraction is negligible. Over 95% of the gas fraction, regardless of the final temperature, is composed of hydrocarbons of a low molecular weight and hydrogen, this fraction also appearing to be free of chlorine

Thermo-hydro-mechanical characterization of the Spanish reference clay material for engineered barrier for granite and clay HLW repository: laboratory and small mock up testing

International Nuclear Information System (INIS)

Villar, M.V.

1995-01-01

This report refers to the work carried out by Technic Geologic Division of CIEMAT (CIEMAT.DT.TG) coordinated by SCK/CEN (Belgium), participating besides UPC-DIT and University of Wales on the framework of CEC Contract F12W-CT91-0102 (DOEO). It presents the results obtained. The total results on the project will be published by CE in the EUR series. The role of CIEMAT in this project was to carry out tests in which the conditions of the clay barrier in the repository were simulated. The interaction of heat coming from the wastes and of water coming from the geological medium has been reproduced on compacted clay blocks. For the performance of tests on high density compacted clay blocks (Task 2.1) and for the cementation and chemical-mineralogical transformation studies two different cells were designed and constructed in stainless steel: a thermohydraulic cell and an alteration cell. The experiments performed in these cells have provided us with a better knowledge of the heat source, hydration system and sensors, as well as interesting data on heat and water diffusion. A revision of the experiments performed on the thermohydraulic cell was presented at the ''International Workshop on Thermomechanics of Clays and Clay Barriers'' held in Bergamo in October'93 (Villar et al. 1993)

Prediction of clay content from water vapour sorption isotherms considering hysteresis and soil organic matter content

DEFF Research Database (Denmark)

Arthur, E.; Tuller, M.; Møldrup, Per

2015-01-01

Soil texture, in particular the clay fraction, governs numerous environmental, agricultural and engineering soil processes. Traditional measurement methods for clay content are laborious and impractical for large-scale soil surveys. Consequently, clay prediction models that are based on water...... within a RH range from 3 to 93%. The clay contents, which ranged between 1 and 56%, were measured with a combination of sieving and sedimentation methods. Two regression models were developed for both adsorption and desorption at 10 RH levels (5, 10, 20, 30, 40, 50, 60, 70, 80 and 90%). While the first...

Evolution of tyre/road noise research in India: Investigations using statistical pass-by method and noise trailer

Directory of Open Access Journals (Sweden)

Vivek Khan

2018-05-01

Full Text Available The objective of this research study was to investigate and analyze the acoustical characteristics of asphalt concrete and cement concrete surface types by two noise measurement techniques: statistical pass-by (SPB and Close Proximity (CPX methods. A noise trailer was devised and manufactured as part of the CPX methodology to evaluate tyre/pavement noise interaction at source. Two national highway test sections covering over 11 km of asphalt and cement concrete surfaces were selected to carry out the noise measurements, and the effects of vehicle speeds and/or sizes on the overall noise profiles were investigated. The major contribution of this first of its kind study in India was the utilization of sophisticated tools and techniques to measure the tyre/pavement interaction noise at source through CPX, which helped correlate the influence of road surfaces on the generation of overall road traffic noise using SPB technique. The SPB method noise profiles revealed that the noise pressure levels increased with increasing vehicle speeds and weights. The noise trailer CPX findings corroborated the results obtained from the SPB method in that cement concrete surface produced a higher noise at source than that of the asphalt concrete surface by about 5 dBA. Further, there was about 5 dBA differential in noise between SPB and CPX methods for cement concrete pavement sections; also, there was about 10 dBA differential in noise between the two methods for asphalt concrete pavement stretches. Keywords: Tyre/road noise, Statistical pass-by, Close proximity, Noise trailer, Asphalt concrete, Cement concrete

Clay Houses

Science.gov (United States)

Pedro, Cathy

2011-01-01

In this article, the author describes a project designed for fourth-graders that involves making clay relief sculptures of houses. Knowing the clay houses will become a family heirloom makes this lesson even more worth the time. It takes three classes to plan and form the clay, and another two to underglaze and glaze the final products.

Fundamentals of fibre-reinforced soil engineering

CERN Document Server

Shukla, Sanjay Kumar

2017-01-01

This book is intended to serve as a one-stop reference on fibre-reinforced soils. Over the past 30-35 years, the engineering behaviour of randomly distributed/oriented fibre-reinforced soil, also called simply fibre-reinforced soil, has been investigated in detail by researchers and engineers worldwide. Waste fibres (plastic waste fibres, old tyre fibres, etc.) create disposal and environmental problems. Utilization of such fibres in construction can help resolve these concerns. Research studies and some field applications have shown that the fibres can be utilized in large quantities in geotechnical and civil engineering applications in a cost-effective and environmentally friendly manner. This book covers a complete description of fibres, their effects when included within a soil or other similar materials such as the fly ash, and their field applications. It gives a detailed view of fibre-reinforced soil engineering. The book will be useful to students, professional, and researchers alike, and can also ser...

Influence of silica-alumina support ratio on H2 production and catalyst carbon deposition from the Ni-catalytic pyrolysis/reforming of waste tyres.

Science.gov (United States)

Zhang, Yeshui; Tao, Yongwen; Huang, Jun; Williams, Paul

2017-10-01

The influence of catalyst support alumina-silica in terms of different Al 2 O 3 to SiO 2 mole ratios containing 20 wt.% Ni on the production of hydrogen and catalyst coke formation from the pyrolysis-catalysis of waste tyres is reported. A two-stage reactor system was used with pyrolysis of the tyres followed by catalytic reaction. There was only a small difference in the total gas yield and hydrogen yield by changing the Al 2 O 3 to SiO 2 mole ratios in the Ni-Al 2 O 3 /SiO 2 catalyst. The 1:1 ratio of Al 2 O 3 :SiO 2 ratio produced the highest gas yield of 27.3 wt.% and a hydrogen production of 14.0 mmol g -1 tyre . Catalyst coke formation decreased from 19.0 to 13.0 wt.% as the Al 2 O 3 :SiO 2 ratio was changed from 1:1 to 2:1, with more than 95% of the coke being filamentous-type carbon, a large proportion of which was multi-walled carbon nanotubes. Further experiments introduced steam to the second-stage reactor to investigate hydrogen production for the pyrolysis-catalytic steam reforming of the waste tyres using the 1:1 Al 2 O 3 /SiO 2 nickel catalyst. The introduction of steam produced a marked increase in total gas yield from ~27 wt. % to ~58 wt.%; in addition, hydrogen production was increased to 34.5 mmol g -1 and there was a reduction in catalyst coke formation to 4.6 wt.%.

Influence of silica–alumina support ratio on H2 production and catalyst carbon deposition from the Ni-catalytic pyrolysis/reforming of waste tyres

Science.gov (United States)

Zhang, Yeshui; Tao, Yongwen; Huang, Jun; Williams, Paul

2017-01-01

The influence of catalyst support alumina–silica in terms of different Al2O3 to SiO2 mole ratios containing 20 wt.% Ni on the production of hydrogen and catalyst coke formation from the pyrolysis-catalysis of waste tyres is reported. A two-stage reactor system was used with pyrolysis of the tyres followed by catalytic reaction. There was only a small difference in the total gas yield and hydrogen yield by changing the Al2O3 to SiO2 mole ratios in the Ni-Al2O3/SiO2 catalyst. The 1:1 ratio of Al2O3:SiO2 ratio produced the highest gas yield of 27.3 wt.% and a hydrogen production of 14.0 mmol g-1tyre. Catalyst coke formation decreased from 19.0 to 13.0 wt.% as the Al2O3:SiO2 ratio was changed from 1:1 to 2:1, with more than 95% of the coke being filamentous-type carbon, a large proportion of which was multi-walled carbon nanotubes. Further experiments introduced steam to the second-stage reactor to investigate hydrogen production for the pyrolysis-catalytic steam reforming of the waste tyres using the 1:1 Al2O3/SiO2 nickel catalyst. The introduction of steam produced a marked increase in total gas yield from ~27 wt. % to ~58 wt.%; in addition, hydrogen production was increased to 34.5 mmol g-1 and there was a reduction in catalyst coke formation to 4.6 wt.%. PMID:28789599

The systems containing clays and clay minerals from modified drug release: a review.

Science.gov (United States)

Rodrigues, Luís Alberto de Sousa; Figueiras, Ana; Veiga, Francisco; de Freitas, Rivelilson Mendes; Nunes, Lívio César Cunha; da Silva Filho, Edson Cavalcanti; da Silva Leite, Cleide Maria

2013-03-01

Clays are materials commonly used in the pharmaceutical industry, either as ingredients or as active ingredients. It was observed that when they are administered concurrently, they may interact with drugs reducing their absorption. Therefore, such interactions can be used to achieve technological and biopharmaceutical advantages, regarding the control of release. This review summarizes bibliographic (articles) and technological (patents) information on the use of systems containing clays and clay minerals in modified drug delivery. In this area, formulations such natural clay, commercial clay, synthetic clay, composites clay-polymers, nanocomposites clay-polymers, films and hidrogels composites clay-polymers are used to slow/extend or vectorize the release of drugs and consequently they increase their bioavailability. Finally, this review summarizes the fields of technology and biopharmaceutical applications, where clays are applied. Copyright © 2012 Elsevier B.V. All rights reserved.

Laboratory and field tests for radionuclide migration and high flow paths in clay

International Nuclear Information System (INIS)

Bourke, P.J.; Jefferies, N.L.; Lineham, T.R.; Nesirky, P.

1991-01-01

Two investigations have been undertaken in this programme. The principal investigation was at Culham Laboratory, England, where water flow within the Kimmeridge clay was measured. A subsidiary investigation at SCK/CEN was undertaken at the Underground Research Laboratory SCK/CEN Mol, Belgium, where an in situ measurement of solute transport by diffusion was attempted. The in situ migration experiment at the Underground Research Laboratory at SCK/CEN Mol, Belgium, was unsuccessful, due to problems with the engineering installation. These difficulties caused significant disturbance to the Boom clay which was to be tested. Nevertheless the laboratory test proved the feasibility of the experiment. The field measurements at Culham Laboratory, Oxfordshire, were completed with the flow testing of a very silty clay horizon in the Kimmeridge clay. This layer was proved to be laterally continuous after drilling three exploratory boreholes. The hydraulic conductivity of the layer was ≥ 10 -8 ms -1 and comparative tests in the clay showed the conductivity of the clay to be at least 50 times less. 12 figs

EFFECTS OF INORGANIC SALT SOLUTION ON SOME PROPERTIES OF COMPACTED CLAY LINERS

Directory of Open Access Journals (Sweden)

KHALID R. MAHMOOD AL-JANABI

2017-12-01

Full Text Available Processed and natural clays are widely used to create impermeable liners in solid waste disposal landfills. The engineering properties of clay liners can be significantly affected by the leachate from the waste mass. In this study, the effect of inorganic salt solutions will be investigated. These solutions used at different concentrations. Two type of inorganic salt MnSO4 and FeCl3 are used at different concentration 2%,5%, 10%. Clay used in this study was the CL- clay (kaolinite. The results show that the consistency limits and unconfined compressive strength increased as the concentration of salts increased. While the permeability tends to decrease as salt concentration increased. Also, the compression index decreases as the concentration increased from 2% to 5%. The swelling index tends to increase slightly as the concentration of MnSO4 increased, while its decrease as the concentration of FeCl3. In this paper, it is aimed to investigate the performance of compacted clay liner exposed to the certain chemicals generated by the leachate and their effects on the geotechnical properties of compacted clay liner such consistency limits, permeability coefficient, compressibility characteristics and unconfined compressive strength.

The influence of various pressures in pneumatic tyre on braking process of car with anti-lock braking system

OpenAIRE

Damian HADRYŚ; Tomasz WĘGRZYN; Michał MIROS

2008-01-01

In this article has been presented the influence of various pressures inpneumatic tyre of passenger car Fiat Panda 1.3 JTD with anti-lock braking system on chosen parameters of braking process: course of braking deceleration, maximum value of deceleration, braking distances.

Preconsolidation of Søvind Marl - a highly fissured Eocene clay

DEFF Research Database (Denmark)

Grønbech, Gitte Lyng; Ibsen, Lars Bo; Nielsen, Benjaminn Nordahl

2015-01-01

Determination of the preconsolidation stresses is a key tool in geotechnical engineering used to evaluate and estimate the behavior of soils. However, it has been proven difficult to accurately estimate the preconsolidation in highly fissured overconsolidated clays, due to the effect of the fissu...

Constitutive relationships for elastic deformation of clay rock: Data Analysis

Energy Technology Data Exchange (ETDEWEB)

Liu, H.H.; Rutqvist, J.; Birkholzer, J.T.

2011-04-15

Geological repositories have been considered a feasible option worldwide for storing high-level nuclear waste. Clay rock is one of the rock types under consideration for such purposes, because of its favorable features to prevent radionuclide transport from the repository. Coupled hydromechanical processes have an important impact on the performance of a clay repository, and establishing constitutive relationships for modeling such processes are essential. In this study, we propose several constitutive relationships for elastic deformation in indurated clay rocks based on three recently developed concepts. First, when applying Hooke's law in clay rocks, true strain (rock volume change divided by the current rock volume), rather than engineering strain (rock volume change divided by unstressed rock volume), should be used, except when the degree of deformation is very small. In the latter case, the two strains will be practically identical. Second, because of its inherent heterogeneity, clay rock can be divided into two parts, a hard part and a soft part, with the hard part subject to a relatively small degree of deformation compared with the soft part. Third, for swelling rock like clay, effective stress needs to be generalized to include an additional term resulting from the swelling process. To evaluate our theoretical development, we analyze uniaxial test data for core samples of Opalinus clay and laboratory measurements of single fractures within macro-cracked Callovo-Oxfordian argillite samples subject to both confinement and water reduced swelling. The results from this evaluation indicate that our constitutive relationships can adequately represent the data and explain the related observations.

Constitutive relationships for elastic deformation of clay rock: Data Analysis

International Nuclear Information System (INIS)

Liu, H.H.; Rutqvist, J.; Birkholzer, J.T.

2011-01-01

Geological repositories have been considered a feasible option worldwide for storing high-level nuclear waste. Clay rock is one of the rock types under consideration for such purposes, because of its favorable features to prevent radionuclide transport from the repository. Coupled hydromechanical processes have an important impact on the performance of a clay repository, and establishing constitutive relationships for modeling such processes are essential. In this study, we propose several constitutive relationships for elastic deformation in indurated clay rocks based on three recently developed concepts. First, when applying Hooke's law in clay rocks, true strain (rock volume change divided by the current rock volume), rather than engineering strain (rock volume change divided by unstressed rock volume), should be used, except when the degree of deformation is very small. In the latter case, the two strains will be practically identical. Second, because of its inherent heterogeneity, clay rock can be divided into two parts, a hard part and a soft part, with the hard part subject to a relatively small degree of deformation compared with the soft part. Third, for swelling rock like clay, effective stress needs to be generalized to include an additional term resulting from the swelling process. To evaluate our theoretical development, we analyze uniaxial test data for core samples of Opalinus clay and laboratory measurements of single fractures within macro-cracked Callovo-Oxfordian argillite samples subject to both confinement and water reduced swelling. The results from this evaluation indicate that our constitutive relationships can adequately represent the data and explain the related observations.

Automotive shredder residue (ASR) and compact disc (CD) waste: options for recovery of materials and energy. Final report for study funded by Ekokem Oy Ab 2002

Energy Technology Data Exchange (ETDEWEB)

Zevenhoven, R.; Saeed, L.

2002-07-01

Automotive shredder residue (ASR) Auto shredder residue (ASR), also referred to as auto shredder fluff, shedder light fraction (SLF), residues from shredding (RESH) or simply 'auto fluff' of 'fluff', is the fraction of an shredded end-of-life vehicle (ELV) for which recycling routes do not yet exist. After removing several recyclable parts such as bumpers (recycled into splash plates or into new bumpers, air bags, batteries, fuel tanks and nowadays also tyres and sometimes even seats, the dismantled vehicle is shredded. The ASR is then obtained as the light shredder fraction from the airflow separator that separates it from the heavier metallic fraction, which is fully recyclable as a secondary raw material. ASR is a complex mixture of plastics (rigid and foam), rubber, glass, wood, paper, leather, textile, sand plus other dirt, and a significant fraction of metals. It may be feasible to remove a large plastics or non-ferrous fraction from the ASR or it may be separated into fractions that contain lighter and heavier fractions, respectively. The ASR fraction is typically around 20 - 25 % of the weight of the ELV it derives from. Whilst for Finland the amount of ASR produced is around 25000 tonnes annually, this number is at least 100 times higher for North America, which suggests that worldwide the annual production will be of the order of 10 million tonnes. Although recycling and recovery of ELV components is increasing the increasing number of vehicles will give a further rise of ASR generated for years to come. Since the mid-1990's there is, however, increased concern over how to handle this waste material and in European countries that follow EU legislations and directives, important changes are being enforced by three new directives: Directive 2000/53/EC (September 18, 2000) on End-of-Life Vehicles, Directive 200/76/EC (December 4, 2000) on the Incineration of Waste and Directive 1999/31/EC (April 26, 1999) on the Landfill of Waste

The influence of various pressures in pneumatic tyre on braking process of car with anti-lock braking system

Directory of Open Access Journals (Sweden)

Damian HADRYŚ

2008-01-01

Full Text Available In this article has been presented the influence of various pressures inpneumatic tyre of passenger car Fiat Panda 1.3 JTD with anti-lock braking system on chosen parameters of braking process: course of braking deceleration, maximum value of deceleration, braking distances.

Geochemical of clay formations : study of Spanish clay REFERENCE

International Nuclear Information System (INIS)

Turrero, M. J.; Pena, J.

2003-01-01

Clay rocks are investigated in different international research programs in order to assess its feasibility for the disposal of high level radioactive wastes. This is because different sepcific aspects: they have low hydraulic conductivity (10''-11-10''-15 m/s), a high sorption capacity, self-sealing capacity of facults and discontinuities and mechanical resistance. Several research programs on clay formations are aimed to study the chemistry of the groundwater and the water-rock reactions that control it: e. g. Boom Clay (Mol, Belgium), Oxford Clay /Harwell, United Kingdom), Toarcian Clay (Tournemire, France), Palfris formation (Wellenberg, Switzerland), Opalinus Clay (Bure, France). Based on these studies, considerable progress in the development of techniques for hydrologic, geochemical and hydrogeochemical characterization of mudstones has been accomplished (e. g. Beaufais et al. 1994, De Windt el al. 1998. Thury and Bossart 1999, Sacchi and Michelot 2000) with important advances in the knowledge of geochemical process in these materials (e. g. Reeder et al. 1993, Baeyens and Brandbury 1994, Beaucaire et al. 2000, Pearson et al., 2003).Furtermore, geochemical modeling is commonly used to simulate the evolution of water chemistry and to understand quantitatively the processes controlling the groundwater chemistry (e. g. Pearson et al. 1998, Tempel and Harrison 2000, Arcos et al., 2001). The work presented here is part of a research program funded by Enresa in the context of its R and D program. It is focused on the characterization of a clay formation (reference Argillaceous Formation, RAF) located within the Duero Basin (north-centralSpain). The characterisation of th ephysical properties,, fluid composition, mineralogy, water-rock reaction processes, geochemical modelling and sorption properties of the clays from the mentioned wells is the main purpose of this work. (Author)

Assessment on the methods of measuring the tyre-road contact patch stresses

Science.gov (United States)

Anghelache, G.; Moisescu, A.-R.; Buretea, D.

2017-08-01

The paper reviews established and modern methods for investigating tri-axial stress distributions in the tyre-road contact patch. The authors used three methods of measuring stress distributions: strain gauge method; force sensing technique; acceleration measurements. Four prototypes of instrumented pins transducers involving mentioned measuring methods were developed. Data acquisitions of the contact patch stresses distributions were performed using each transducer with instrumented pin. The results are analysed and compared, underlining the advantages and drawbacks of each method. The experimental results indicate that the three methods are valuable.

An Evaluation of the Resilient Modulus and Permanent Deformation of Unbound Mixtures of Granular Materials and Rubber Particles from Scrap Tyres to be Used in Subballast Layers

OpenAIRE

Signes, Carlos Hidalgo; Fernández, Pablo Martínez; Garzón-Roca, Julio; de la Torre, María Elvira Garrido; Franco, Ricardo Insa

2016-01-01

[EN] Over the last years rubber from scrap tyres has been reused in different civil works such as road embankments and railway platforms due to its resilient properties, low degradation and vibration attenuation. Unfortunately, this issue is still scarce. For instance, in Spain about 175.000 tonnes of scrap tyres were collected in 2014, of which only 0.6% were reused in civil works. Aiming to contribute to the reutilisation of large quantities of this waste material, this paper focuses on the...

An Evaluation of the Resilient Modulus and Permanent Deformation of Unbound Mixtures of Granular Materials and Rubber Particles from Scrap Tyres to Be Used in Subballast Layers

OpenAIRE

Hidalgo Sgnes, Carlos; Martínez Fernández, Pablo; Garzón Roca, Julio; Garrido De La Torre, Mª Elvira; Insa Franco, Ricardo

2016-01-01

[EN] Over the last years rubber from scrap tyres has been reused in different civil works such as road embankments and railway platforms due to its resilient properties, low degradation and vibration attenuation. Unfortunately, this issue is still scarce. For instance, in Spain about 175.000 tonnes of scrap tyres were collected in 2014, of which only 0.6% were reused in civil works. Aiming to contribute to the reutilisation of large quantities of this waste material, this paper focuses on the...

Advanced 2D and 3D Electron Microscopy Analysis of Clay/PP Nanocomposites

DEFF Research Database (Denmark)

Mosca, Alessandra; Roberts, Ashley; Daviðsdóttir, Svava

2011-01-01

) equipped with field emission gun (FEG) and through lens detector (TLD) was used for high resolution 3D imaging of the material via slice-and-view technique [2]. Image analysis was performed using Matlab. Results and Discussion Figure 1 (a) shows a TEM micrograph of a clay/PP nanocomposite, where the clay...... of nanometres and are rather uniformly oriented, distributed, and spaced from each other. Image analysis from these micrographs is very useful since a rather large field view is analysed as compared to TEM micrographs, which are traditionally used to study such properties. Figure 3 (a) shows a high resolution......Introduction Clay/polypropylene (PP) nanocomposites with engineered properties are attractive in developing novel components of interest in a plurality of application fields [1]. An understanding of clay dispersion and intercalation in the polymeric matrix is of great importance to explain...

A minimalistic microbial food web in an excavated deep subsurface clay rock.

Science.gov (United States)

Bagnoud, Alexandre; de Bruijn, Ino; Andersson, Anders F; Diomidis, Nikitas; Leupin, Olivier X; Schwyn, Bernhard; Bernier-Latmani, Rizlan

2016-01-01

Clay rocks are being considered for radioactive waste disposal, but relatively little is known about the impact of microbes on the long-term safety of geological repositories. Thus, a more complete understanding of microbial community structure and function in these environments would provide further detail for the evaluation of the safety of geological disposal of radioactive waste in clay rocks. It would also provide a unique glimpse into a poorly studied deep subsurface microbial ecosystem. Previous studies concluded that microorganisms were present in pristine Opalinus Clay, but inactive. In this work, we describe the microbial community and assess the metabolic activities taking place within borehole water. Metagenomic sequencing and genome-binning of a porewater sample containing suspended clay particles revealed a remarkably simple heterotrophic microbial community, fueled by sedimentary organic carbon, mainly composed of two organisms: a Pseudomonas sp. fermenting bacterium growing on organic macromolecules and releasing organic acids and H2, and a sulfate-reducing Peptococcaceae able to oxidize organic molecules to CO(2). In Opalinus Clay, this microbial system likely thrives where pore space allows it. In a repository, this may occur where the clay rock has been locally damaged by excavation or in engineered backfills. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Pyrolysis process application on scrap tyres. Experimental results on pilot scale; Applicazione del processo di pirolisi al trattamento del granulato di pneumatico. Sperimentazione su impianto pilota

Energy Technology Data Exchange (ETDEWEB)

Galvagno, S.; Casu, S.; Casabianca, T.; Calabrese, A.; Cornacchia, G. [ENEA, Dipartimento Ambiente, Centro Ricerche Trisaia, Rotondella, MT (Italy)

2001-04-01

The world production of waste tyres amounts to 5 {center_dot} 10{sup 6} ton/year, 2 {center_dot} 10{sup 6} tons of which are produced in Europe; the Italian production of waste tyres is up to 360 thousand tons per year. Even today, the final destination of nearly 65-70% of waste tyres is the landfill, legal or illegal; but this solution seems to be not so advantageous, as far as the high added value materials lost and the environmental impact are concerned. Treatments alternative to land filling take into account the tyres reconstruction and reuse or the matter and/or energy recovery by means of thermal treatment processes. With respect to the latter processes, the pyrolysis process definitely shows the less environmental impact and gets to process products (gases, oils and solid residue) able to be back on the market after the suitable treatment. Present work shows the results of the pyrolysis process experimental survey on tyres granulate, developed on the pilot plant of ENEA-Trisaia Research Centre. [Italian] La produzione mondiale di pneumatici usati conta annualmente piu' di 5 milioni di tonnellate di cui 2 milioni generati in Europa: in Italia, sono generate circa 360 mila tonnellate l'anno di pneumatici usati. Il destino finale del 65-70% dei pneumatici usati e' ancora oggi lo smaltimento in discarica, sia essa autorizzata o abusiva; questa soluzione risulta poco vantaggiosa per la perdita di materiali che in precedenza possedevano un alto valore aggiunto e in termini d'impatto ambientale. Trattamenti alternativi alla discarica, prevedono la ricostruzione e il riutilizzo oppure il recupero di materia e/o di energia mediante processi di trattamento termico. Tra questi ultimi il processo di pirolisi presenta senz'altro il minor impatto ambientale e conduce a prodotti di processo (gas, olii e residuo solido) che, opportunamente trattati, possono essere immessi sul mercato. Questo lavoro presenta i risultati della sperimentazione del

Emissions of road dust by winter tyres and the contributions of different road dust sources in road side particle samples; Talvirenkaiden poelypaeaestoet ja eri katupoelylaehteiden osuudet kadunvarrella keraetyissae hiukkasnaeytteissae

Energy Technology Data Exchange (ETDEWEB)

Kupiainen, K.; Pirjola, L.; Ritola, R.; Stojiljkovic, A.; Malinen, A.

2013-09-01

Aim of this study was to determine: (1) the relative contributions from pavement wear and traction sanding in PM{sub 10} road side air and road dust resuspension samples; (2) PM{sub 10} dust emissions from studded and studless tyres in on-road conditions. The study was conducted as part of the NASTA research program during the winter season 2011/2012. The studies were carried out in Suurmetsaentie and Viikintie in Helsinki, Finland. The results showed that dust from pavement aggregates was the largest source during spring, accounting for 40- 50 percent of the particulate matter in the air and resuspension samples. Based on studies on formation of dust, major source of the dust from pavement aggregates is the wear by studded tyres. Traction sand and road salt were used frequently during the winter 2011/2012. Sanding material explained about 25 percent of the road dust in the air and resuspension samples. Traction sanding is estimated to account for approximately few percent of the pavement dust via the sandpaper effect. Effect of road salt was few percent in the samples. The source contributions from pavement and traction sanding observed in spring 2011/2012 at Suurmetsaentie are similar to what has been estimated in previous studies conducted in the early 2000s in Finland. In a study conducted in the city of Hanko, it was estimated the contribution from traction sanding to be in average of about 10 percent. In another study in the center of Helsinki the contribution was estimated to be about half of the PM{sub 10}. The general perception in Finland has been that traction sanding is the main source of airborne road dust. Studies conducted in 2000s and the results of this study, however, indicate that traction sanding has been an important but not the main source of PM10 road dust even in winters with extensive use of gravel for traction control. Emissions of road dust by a single tyre consist of direct emissions of wear products as well as resuspension emissions of

Nearfield behaviour of clay barriers and their interaction with concrete Task 3 characterization of radioactive waste forms a series of final reports (1985-89) No 26

International Nuclear Information System (INIS)

Atabek, R.; Beziat, A.; Coulon, H.; Dardaine, M.; Eglem, A.; Farcy, C.; Fontan, N.; Gatabin, C.; Gegout, P.; Lajudie, A.; Landoas, O.; Lechelle, J.; Plas, F.; Raynal, J.; Revertegat, E.; Debrabant, P.; Proust, D.

1991-01-01

In order to guarantee the safety of waste underground disposal, engineered barriers will be implemented as backfill materials in galleries and access shafts and as buffer materials between the host medium and the waste packages. One of the first requirements for engineered barriers is to minimize water and chemical species transfer. The materials being considered are essentially swelling clays, in particular calcium smectite clays coming from french deposits and hydraulic binders, more specially a ternary cement (named C.L.C.). A vitrified waste disposal in granite is taken as the most constraining scenario as far as engineered barrier is concerned. The clay buffer material is placed between the packages and the host rock. The main properties which are determined are directly related to the engineered barrier requirements: thermal conductivity, hydraulic conductivity, swelling pressure and swelling capacity. Moreover results are obtained on temperature effect on clay microstructure and properties in both cases: without and with water intake. The concrete durability with regard to clay pore water attack is evaluated taking into account previous results obtained to ensure low-level radioactive waste disposal safety. 23 refs., 29 figs., 10 tabs

Comprehensive review of geosynthetic clay liner and compacted clay liner

Science.gov (United States)

Shankar, M. Uma; Muthukumar, M.

2017-11-01

Human activity inevitably produces waste materials that must be managed. Some waste can be reused. However many wastes that cannot be used beneficially must be disposed of ensuring environmental safety. One of the common methods of disposal is landfilling. The most common problems of the landfill site are environmental degradation and groundwater contamination caused by leachate produced during the decomposition process of organic material and rainfall. Liner in a landfill is an important component which prevent leachate migration and prevent groundwater contamination. Earthen liners have been widely used to contain waste materials in landfill. Liners and covers for municipal and hazardous waste containment facilities are often constructed with the use of fine-grained, low plasticity soils. Because of low permeability geosynthetic clay liners and compacted clay liners are the main materials used in waste disposal landfills. This paper summaries the important geotechnical characteristics such as hydraulic conductivity, liquid limit and free swell index of geosynthetic clay liner and compacted clay liner based on research findings. This paper also compares geosynthetic clay liner and compacted clay liner based on certain criteria such as thickness, availability of materials, vulnerability to damage etc.

State boundary surface of a hypoplastic model for clays

Czech Academy of Sciences Publication Activity Database

Mašín, David; Herle, Ivo

2005-01-01

Roč. 32, č. 6 (2005), s. 400-410 ISSN 0266-352X R&D Projects: GA ČR(CZ) GA103/04/0672 Grant - others:Evropská komise SSPI-CT-2003-501837 Institutional research plan: CEZ:AV0Z20710524 Keywords : hypoplasticity * clay * limit state Subject RIV: JM - Building Engineering Impact factor: 0.562, year: 2005

Mechanical characterization of sportive tracks made with materials recycled from end-of-life tyres

OpenAIRE

Morales-Gámiz, F. J.; Escriba, S.; García-Villena, S. A.; Bermejo, J. M.; Saiz, L.

2015-01-01

Congreso celebrado en la Escuela de Arquitectura de la Universidad de Sevilla desde el 24 hasta el 26 de junio de 2015. The European Framework Directive 2008/98/EC on waste established as priority reuse and recycling before other recovery alternatives. In this normative reference, one the main waste flows identified are the end-of-life tyres, as a material whose mechanical properties could provide advantage in the construction of new structures. This paper presents the mechanical character...

Preparation and Characterization of Acid and Alkaline Treated Kaolin Clay

Directory of Open Access Journals (Sweden)

Sachin Kumar

2013-06-01

Full Text Available Kaolin was refluxed with HNO3, HCl, H3PO4, CH3COOH, and NaOH of 3M concentration at 110 °C for 4 hours followed by calcination at 550 °C for 2 hours. The physico-chemical characteristics of resulted leached kaolinite clay were studied by XRF, XRD, FTIR, TGA, DTA, SEM and N2 adsorption techniques. XRF and FTIR study indicate that acid treatment under reflux conditions lead to the removal of the octahedral Al3+ cations along with other impurities. XRD of acid treated clay shows that, the peak intensity was found to decrease. Extent of leaching of Al3+ ions is different for different acid/base treatment. The acid treatment increased the Si/Al ratio, surface area and pore volume of the clay. Thus, the treated kaolin clay can be used as promising adsorbent and catalyst supports. © 2013 BCREC UNDIP. All rights reservedReceived: 1st March 2013; Revised: 9th April 2013; Accepted: 19th April 2013[How to Cite: Kumar, S., Panda, A. K., Singh, R.K. (2013. Preparation and Characterization of Acids and Alkali Treated Kaolin Clay. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (1: 61-69. (doi:10.9767/bcrec.8.1.4530.61-69][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.1.4530.61-69] |View in  |

Clay dispersibility and soil friability – testing the soil clay-to-carbon saturation concept

OpenAIRE

Schjønning, P.; de Jonge, L.W.; Munkholm, L.J.; Moldrup, P.; Christensen, B.T.; Olesen, J.E.

2011-01-01

Soil organic carbon (OC) influences clay dispersibility, which affects soil tilth conditions and the risk of vertical migration of clay colloids. No universal lower threshold of OC has been identified for satisfactory stabilization of soil structure. We tested the concept of clay saturation with OC as a predictor of clay dispersibility and soil friability. Soil was sampled three years in a field varying in clay content (~100 to ~220 g kg-1 soil) and grown with different crop rotations. Clay ...

SIMS depth profiling of rubber-tyre cord bonding layers prepared using 64Zn depleted ZnO

International Nuclear Information System (INIS)

Fulton, W.S.; Sykes, D.E.; Smith, G.C.

2006-01-01

Zinc oxide and copper/zinc sulphide layers are formed during vulcanisation and moulding of rubber to brass-coated steel tyre reinforcing cords. Previous studies have described how zinc diffuses through the rubber-brass interface to form zinc sulphide, and combines with oxygen to create zinc oxide during dezincification. The zinc is usually assumed to originate in the brass of the tyre cord, however, zinc oxide is also present in the rubber formulation. We reveal how zinc from these sources is distributed within the interfacial bonding layers, before and after heat and humidity ageing. Zinc oxide produced using 64 Zn-isotope depleted zinc was mixed in the rubber formulation in place of the natural ZnO and the zinc isotope ratios within the interfacial layers were followed by secondary ion mass spectroscopy (SIMS) depth profiling. Variations in the relative ratios of the zinc isotopes during depth profiling were measured for unaged, heat-aged and humidity-aged wire samples and in each case a relatively large proportion of the zinc incorporated into the interfacial layer as zinc sulphide was shown to have originated from ZnO in the rubber compound

Practical technical solution for clay-contaminated sands used in concrete

Directory of Open Access Journals (Sweden)

Estephane Pierre

2017-01-01

Full Text Available Sand, whether natural or manufactured, shows in many instances varying degrees of high levels of clay contamination. This fact is encountered in different parts of the globe and can lead to serious problems in adjusting concrete mix proportions and requiring high water to cement ratios and/or high dosages of superplasticizers without necessarily meeting the workability requirements, even when the sand is previously washed with fresh water. In this paper, different types of sand from the Gulf Cooperation Council (GCC region are being screened, analysed for their clay contents and consequent effects on plastic concrete quality. A technical solution is being proposed based on engineered superplasticizers. A testing protocol has been established to verify the robustness of optimized mix designs demonstrating the performance of the admixture in terms of initial and extended workability. In particular, it will be demonstrated that the customized concrete admixtures constitute by themselves a stand-alone answer to the usage of clay-contaminated sands in concrete.

Evaluation of impact strength of polyamide 6/bentonite clay nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Paz, Rene Anisio; Araujo, Edcleide Maria; Tomas Jeferson Alves; Amanda Damiao; Medeiros, Vanessa da Nobrega [Federal University of Campina Grande (CCT/UFCG), Campina Grande, PB (Brazil). Centro de Ciencias e Tecnologia; Pessan, Luiz Antonio [Federal University of Sao Carlos (DEMa/UFSCar), SP (Brazil). Materials Engineering Department

2012-07-15

Nanocomposites of polymer/clay have had much attention in recent years, particularly those developed with layered silicates due to the need of engineering materials more efficient than pure polymers for certain applications. The level of exfoliation of layered silicates in crystalline structure of polymer matrices has been studied and has been observed that it affects the crystalline behavior and the physical and mechanical properties. In this study, nanocomposites of polyamide 6 were obtained by the melt intercalation method, using a Brazilian bentonite modified with a quaternary ammonium salt. X-Ray Diffraction (XRD) results showed the incorporation of salt among the layers of clay, making it organophilic and that the nanocomposites presented exfoliated and/or partially exfoliated structures and confirmed by transmission electron microscopy (TEM). By thermogravimetry (TG), the results indicated that the presence of clay increased the thermal stability of polyamide 6. The impact properties of the nanocomposites showed inferior values in relation to the pure polyamide, in other words, decrease the toughness. (author)

Evaluation of impact strength of polyamide 6/bentonite clay nanocomposites

International Nuclear Information System (INIS)

Paz, Rene Anisio; Araujo, Edcleide Maria; Tomas Jeferson Alves; Amanda Damiao; Medeiros, Vanessa da Nobrega; Pessan, Luiz Antonio

2012-01-01

Nanocomposites of polymer/clay have had much attention in recent years, particularly those developed with layered silicates due to the need of engineering materials more efficient than pure polymers for certain applications. The level of exfoliation of layered silicates in crystalline structure of polymer matrices has been studied and has been observed that it affects the crystalline behavior and the physical and mechanical properties. In this study, nanocomposites of polyamide 6 were obtained by the melt intercalation method, using a Brazilian bentonite modified with a quaternary ammonium salt. X-Ray Diffraction (XRD) results showed the incorporation of salt among the layers of clay, making it organophilic and that the nanocomposites presented exfoliated and/or partially exfoliated structures and confirmed by transmission electron microscopy (TEM). By thermogravimetry (TG), the results indicated that the presence of clay increased the thermal stability of polyamide 6. The impact properties of the nanocomposites showed inferior values in relation to the pure polyamide, in other words, decrease the toughness. (author)

Characterization of Swelling Clays as Components of the Engineered Barrier System for Geological Repositories. Results of an IAEA Coordinated Research Project 2002-2007

International Nuclear Information System (INIS)

2013-11-01

At the request of the Member States, the IAEA coordinates research into subjects of common interest in the context of the peaceful application of nuclear technology. The coordinated research projects (CRPs) are intended to promote knowledge and technology transfer between Member States and are largely focused on subjects of prime interest to the international nuclear community. This report presents the results of a CRP carried out between 2002 and 2007 on the subject of swelling clays proposed for use as a component in the engineered barrier system (EBS) of the multibarrier concept for disposal of radioactive waste. In 2002, under the auspices of the IAEA, a number of Member States came together to form a Network of Centres of Excellence on Training in and Demonstration of Waste Disposal Technologies in Underground Research Facilities (URF Network). This network identified the general subject of the application of high swelling clays to seal repositories for radioactive waste, with specific emphasis on the isolation of high level radioactive waste from the biosphere, as being suitable for a CRP. Existing concepts for geological repositories for high level radioactive waste and spent nuclear fuel require the use of EBSs to ensure effective isolation of the radioactive waste. There are two major materials proposed for use in the EBS, swelling clay based materials and cementitious/concrete materials. These materials will be placed between the perimeter of the excavation and the waste container to fill the existing gap and ensure isolation of the waste within the canister (also referred to as a container in some EBS concepts) by supporting safety through retardation and confinement. Cementitious materials are industrially manufactured to consistent standards and are readily available in most locations and therefore their evaluation is of less value to Member States than that of swelling clays. There exists a considerable range of programme development regarding

Multiscale Micromechanical Modeling of Polymer/Clay Nanocomposites and the Effective Clay Particle

Science.gov (United States)

Sheng, Nuo; Boyce, Mary C.; Parks, David M.; Manovitch, Oleg; Rutledge, Gregory C.; Lee, Hojun; McKinley, Gareth H.

2003-03-01

Polymer/clay nanocomposites have been observed to exhibit enhanced mechanical properties at low weight fractions (Wp) of clay. Continuum-based composite modeling reveals that the enhanced properties are strongly dependent on particular features of the second-phase ¡°particles¡+/-; in particular, the particle volume fraction (fp), the particle aspect ratio (L/t), and the ratio of particle mechanical properties to those of the matrix. However, these important aspects of as-processed nanoclay composites have yet to be consistently and accurately defined. A multiscale modeling strategy was developed to account for the hierarchical morphology of the nanocomposite: at a lengthscale of thousands of microns, the structure is one of high aspect ratio particles within a matrix; at the lengthscale of microns, the clay particle structure is either (a) exfoliated clay sheets of nanometer level thickness or (b) stacks of parallel clay sheets separated from one another by interlayer galleries of nanometer level height. Here, quantitative structural parameters extracted from XRD patterns and TEM micrographs are used to determine geometric features of the as-processed clay ¡°particles¡+/-, including L/t and the ratio of fp to Wp. These geometric features, together with estimates of silicate lamina stiffness obtained from molecular dynamics simulations, provide a basis for modeling effective mechanical properties of the clay particle. The structure-based predictions of the macroscopic elastic modulus of the nanocomposite as a function of clay weight fraction are in excellent agreement with experimental data. The adopted methodology offers promise for study of related properties in polymer/clay nanocomposites.

Clay intercalation and influence on crystallinity of EVA-based clay nanocomposites

International Nuclear Information System (INIS)

Chaudhary, D.S.; Prasad, R.; Gupta, R.K.; Bhattacharya, S.N.

2005-01-01

Various polymer clay nanocomposites (PCNs) were prepared from ethylene vinyl acetate copolymer (EVA) with 9, 18 and 28% vinyl acetate (VA) content filled with different wt.% (2.5, 5 and 7.5) of a Montmorillonite-based organo-modified clay (Cloisite[reg] C15A and C30B). The PCNs were prepared using melt blending techniques. Morphological information regarding intercalation and exfoliation were determined by using wide-angle X-ray scattering (WAXS) and transmission electron microscopy (TEM). WAXS and TEM confirmed that increasing the VA content was necessary to achieve greater clay-polymer interaction as seen from the comparatively higher intercalation of clay platelets with 28% VA. The effect of addition of clay on the development and the modification of crystalline morphology in EVA matrix was also studied using WAXS and temperature-modulated differential scanning calorimetry (MDSC). Results are presented showing that the addition of clay platelets does not increase the matrix crystallinity but the morphology was significantly modified such that there was an increase in the 'rigid' amorphous phase. Mechanical properties were also evaluated against the respective morphological information for each specimen and there are indications that the level of clay-polymer interaction plays a significant role in such morphological modification, and in such a way that affects the final PCN mechanical properties which has wide and significant applications in the packaging industries

Clay Dispersibility and Soil Friability-Testing the Soil Clay-to-Carbon Saturation Concept

DEFF Research Database (Denmark)

Schjønning, Per; de Jonge, Lis Wollesen; Munkholm, Lars Juhl

2012-01-01

Soil organic carbon (OC) influences clay dispersibility, which affects soil tilth conditions and the risk of vertical migration of clay colloids. No universal lower threshold of OC has been identified for satisfactory stabilization of soil structure. We tested the concept of clay saturation with OC...... as a predictor of clay dispersibility and soil friability. Soil was sampled 3 yr in a field varying in clay content (∼100 to ∼220 g kg−1 soil) and grown with different crop rotations. Clay dispersibility was measured after end-over-end shaking of field-moist soil and 1- to 2-mm sized aggregates either air......-dried or rewetted to −100 hPa matric potential. Tensile strength of 1- to 2-, 2- to 4-, 4- to 8-, and 8- to 16-mm air-dried aggregates was calculated from their compressive strength, and soil friability estimated from the strength–volume relation. Crop rotation characteristics gave only minor effects on clay...

Frictional contact behaviour of the tyre: the effect of tread slip on the in-plane structural deformation and stress field development

Science.gov (United States)

Tsotras, Achillefs; Mavros, George

2010-08-01

The analysis of the in-plane deformation of the tyre in relation to the frictional contact between the road and the tread is a crucial first step in the understanding of its contribution to the longitudinal dynamics of a vehicle. In this work, the physical mechanism of the generation of the two-dimensional contact pressure distribution for a non-rolling tyre is studied. Towards this aim, a physical tyre model is constructed, consisting of an analytical ring under pretension, a non-linear sidewall foundation, and a discretised foundation of viscoelastic elements representing the tread. Tread behaviour is examined first, with focus on the development of shear micro-slip. The tread simulation is enhanced with the combination of radial and tangential tread elements and the benefits of such an approach are identified. Subsequently, the contact of the complete model is examined by implementing an algorithm for transient simulations in the time domain. The effects of the imposed vertical load and sidewall non-linearity on the contact stress and strain fields are identified. The modelling approach is validated by comparison with published experimental results. The physical mechanism that couples the torsional and horizontal/vertical deformations of the carcass with the frictional forces at the tread is identified and discussed in detail. The proposed modelling approach is found appropriate for the description of the development of the two-dimensional contact pressure field as a function of the frictional potential of the contact.

SBR Brazilian organophilic/clay nanocomposites

International Nuclear Information System (INIS)

Guimaraes, Thiago R.; Valenzuela-Diaz, Francisco R.; Morales, Ana Rita; Paiva, Lucilene B.

2009-01-01

The aim of this work is the obtaining of SBR composites using a Brazilian raw bentonite and the same bentonite treated with an organic salt. The clays were characterized by XRD. The clay addition in the composites was 10 pcr. The composites were characterized by XRD and had measured theirs tension strength (TS). The composite with Brazilian treated clay showed TS 233% higher than a composite with no clay, 133% higher than a composite with Cloisite 30B organophilic clay and 17% lower than a composite with Cloisite 20 A organophilic clay. XRD and TS data evidence that the composite with Brazilian treated clay is an intercalated nanocomposite. (author)

Atrazine biodegradation modulated by clays and clay/humic acid complexes

International Nuclear Information System (INIS)

Besse-Hoggan, Pascale; Alekseeva, Tatiana; Sancelme, Martine; Delort, Anne-Marie; Forano, Claude

2009-01-01

The fate of pesticides in the environment is strongly related to the soil sorption processes that control not only their transfer but also their bioavailability. Cationic (Ca-bentonite) and anionic (Layered Double Hydroxide) clays behave towards the ionisable pesticide atrazine (AT) sorption with opposite tendencies: a noticeable sorption capacity for the first whereas the highly hydrophilic LDH showed no interactions with AT. These clays were modified with different humic acid (HA) contents. HA sorbed on the clay surface and increased AT interactions. The sorption effect on AT biodegradation and on its metabolite formation was studied with Pseudomonas sp. ADP. The biodegradation rate was greatly modulated by the material's sorption capacity and was clearly limited by the desorption rate. More surprisingly, it increased dramatically with LDH. Adsorption of bacterial cells on clay particles facilitates the degradation of non-sorbed chemical, and should be considered for predicting pesticide fate in the environment. - The biodegradation rate of atrazine was greatly modulated by adsorption of the pesticide and also bacterial cells on clay particles.

Influence of Polymer-Clay Interfacial Interactions on the Ignition Time of Polymer/Clay Nanocomposites.

Science.gov (United States)

Zope, Indraneel S; Dasari, Aravind; Yu, Zhong-Zhen

2017-08-11

Metal ions present on smectite clay (montmorillonite) platelets have preferential reactivity towards peroxy/alkoxy groups during polyamide 6 (PA6) thermal decomposition. This changes the decomposition pathway and negatively affects the ignition response of PA6. To restrict these interfacial interactions, high-temperature-resistant polymers such as polyetherimide (PEI) and polyimide (PI) were used to coat clay layers. PEI was deposited on clay by solution-precipitation, whereas PI was deposited through a solution-imidization-precipitation technique before melt blending with PA6. The absence of polymer-clay interfacial interactions has resulted in a similar time-to-ignition of PA6/PEI-clay (133 s) and PA6/PI-clay (139 s) composites as neat PA6 (140 s). On the contrary, PA6 with conventional ammonium-based surfactant modified clay has showed a huge drop in time-to-ignition (81 s), as expected. The experimental evidences provided herein reveal the role of the catalytic activity of clay during the early stages of polymer decomposition.

Heteroaggregation of Silver Nanoparticles with Clay Minerals in Aqueous System

Science.gov (United States)

Liu, J.; Burrow, E.; Hwang, Y.; Lenhart, J.

2013-12-01

Tween-coated silver nanoparticles showed high stability in both single and binary systems. There were no significant differences in early stage aggregation kinetics observed inthe Na-clay-nanoparticle or Ca-clay-nanoparticle systems, which suggested that the CCC values of the single Na- or Ca-clay suspensions depend only on the electrolyte concentration, not the original cations on the clay surface. These results provide a basic idea for understanding the heteroaggregation of different silver nanoparticles and clays, which can be utilized in further study of fate and transport of engineered nanoparticles in natural aqueous system.

Phosphonium modified clay/polyimide nanocomposites

International Nuclear Information System (INIS)

Ceylan, Hatice; Çakmakçi, Emrah; Beyler-Çiǧil, Asli; Kahraman, Memet Vezir

2014-01-01

In this study, octyltriphenylphosphonium bromide [OTPP-Br] was prepared from the reaction of triphenylphosphine and 1 -bromooctane. The modification of clay was done by ion exchange reaction using OTPP-Br in water medium. Poly(amic acid) was prepared from the reaction of 3,3',4,4'-Benzophenonetetracarboxylic dianhydride (BTDA) and 4,4'-Oxydianiline (ODA). Polyimide(PI)/clay hybrids were prepared by blending of poly(amic acid) and organically modified clay as a type of layered clays. The morphology of the Polyimide/ phosphonium modified clay hybrids was characterized by scanning electron microscopy (SEM). Chemical structures of polyimide and Polyimide/ phosphonium modified clay hybrids were characterized by FTIR. SEM and FTIR results showed that the Polyimide/ phosphonium modified clay hybrids were successfully prepared. Thermal properties of the Polyimide/ phosphonium modified clay hybrids were characterized by thermogravimetric analysis (TGA)

Investigations of excavated clay-stone as backfill/seal material

International Nuclear Information System (INIS)

Zhang, Chun-Liang

2012-01-01

certain densities between 1.56 g/cm 3 for pure MX80 and 2.02 g/cm 3 for pure COX powder under load of 30 MPa. Generally, the seals to be constructed in boreholes, drifts and shafts must have certain swelling capacity for sealing of possibly remaining gaps within the seals and the seal/rock interfaces and for supporting the surrounding rock against damage propagation. Low hydraulic conductivities are also required for the seals against fluid transport. Figure 2 illustrates the swelling pressures measured on two compacted COX+MX80 mixtures and the related water permeabilities. It is obvious that drying led to a rapid drop of the pre-applied stress down to zero and wetting contrarily gave a stress rising up to 4.0-4.7 MPa in humid environment and even higher up to 6.0 MPa when contacting with synthetic pore water. Among the tested mixtures, the maximum swelling pressure of 9.5 MPa was observed on the compacted COX/MX80-mixture with a ratio of 50/50 and with coarse-grains of a size up to 10 mm. This suggests that the mixtures can be optimized with adequate amount of expansive bentonite filling the macro-pores between large clay-stone grains. The water permeability values of 10 -19 - 10 -20 m 2 obtained on the compacted clay-stone-bentonite mixtures are very close to that of the intact clay rock. Thermal properties of compacted crushed clay-stone were determined as function of porosity and water saturation. While the specific heat capacity was measured on average at 900 Jkg -1 K -1 , the thermal conductivity increases with water saturation from 0.8 Wm -1 K -1 at dry conditions to 1.6 Wm -1 K -1 at saturated conditions. The thermal properties of compacted clay-stone backfill are comparable with those of compacted bentonite. These preliminary results promote us to continue the investigations on the excavated clay-stone and clay-stone-bentonite mixtures for design of the engineered barrier system with regard to the specific functional requirements, for development of constitutive

Tyres and road surfaces : paper presented to the Second Internation Skid Prevention Conference, Columbus, Ohio, May 2-6, 1977.

NARCIS (Netherlands)

Schlösser, L.H.M.

1999-01-01

The study concerning the contact between a tyre and a road surface was conducted by means of an experimental multifactor investigation. It was attempted not only to determine the effect of variables such as type of road surface and speed on the skid resistance but also interaction effects. In the

Evaluation of Used Fuel Disposition in Clay-Bearing Rock

Energy Technology Data Exchange (ETDEWEB)

Jove-Colon, Carlos F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Weck, Philippe F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hammond, Glenn Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kuhlman, Kristopher L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zheng, Liange [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rutqvist, Jonny [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kim, Kunhwi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Houseworth, James [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Caporuscio, Florie Andre [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cheshire, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Palaich, Sarah [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Norskog, Katherine E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wolery, Thomas J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jerden, James L. [Argonne National Lab. (ANL), Argonne, IL (United States); Copple, Jacqueline M. [Argonne National Lab. (ANL), Argonne, IL (United States); Cruse, Terry [Argonne National Lab. (ANL), Argonne, IL (United States); Ebert, William L. [Argonne National Lab. (ANL), Argonne, IL (United States)

2015-09-04

Deep geological disposal of nuclear waste in clay/shale/argillaceous rock formations has received much consideration given its desirable attributes such as isolation properties (low permeability), geochemically reduced conditions, slow diffusion, sorbtive mineralogy, and geologically widespread (Jové Colón et al., 2014). There is a wealth of gained scientific expertise on the behavior of clay/shale/ argillaceous rock given its focus in international nuclear waste repository programs that includes underground research laboratories (URLs) in Switzerland, France, Belgium, and Japan. Jové Colón et al. (2014) have described some of these investigative efforts in clay rock ranging from site characterization to research on the engineered barrier system (EBS). Evaluations of disposal options that include nuclear waste disposition in clay/shale/argillaceous rock have determined that this host media can accommodate a wide range of waste types. R&D work within the Used Fuel Disposition Campaign (UFDC) assessing thermal effects and fluid-mineral interactions for the disposition of heat-generating waste have so far demonstrated the feasibility for the EBS and clay host rock to withstand high thermal loads. This report represents the continuation of disposal R&D efforts on the advancement and refinement of coupled Thermal-Hydrological-Mechanical-Chemical (THMC), hydrothermal experiments on clay interactions, used fuel degradation (source term), and thermodynamic modeling and database development. The development and implementation of a clay/shale/argillite reference case described in Jové Colón et al. (2014) for FY15 will be documented in another report (Mariner et al. 2015) – only a brief description will be given here. This clay reference case implementation is the result of integration efforts between the GDSA PA and disposal in argillite work packages. The assessment of sacrificial zones in the EBS is being addressed through experimental work along with 1D reactive

Geology and bedrock engineering

International Nuclear Information System (INIS)

1985-11-01

This book deals with geology of Korea which includes summary, geology in central part and southern part in Korea and characteristic of geology structure, limestone like geology property of limestone, engineered property of limestone, and design and construction case in limestone area. It also introduces engineered property of the cenozoic, clay rock and shale, geologic and engineered property of phyllite and stratum.

MODELLING AND VALIDATION OF A TESTING TRAILER FOR ABS AND TYRE INTERACTION ON ROUGH TERRAIN

OpenAIRE

Žuraulis, Vidas; van der Merwe, Nico A.; Scholtz, Odette; Els, P. Schalk

2017-01-01

The main purpose of a vehicle anti-lock braking system (ABS) is to prevent the tyres from locking-up in order to brake efficiently whilst maintaining steering control and stability. Sport utility vehicles (SUV) are designed to drive on various roads under different driving conditions, making it challenging to identify optimal operating conditions for ABS algorithms to be implemented. This paper describes the development and modelling of a testing trailer that is designed to benefit the res...

Common clay and shale

Science.gov (United States)

Virta, R.L.

2000-01-01

Part of the 1999 Industrial Minerals Review. The clay and shale market in 1999 is reviewed. In the U.S., sales or use of clay and shale increased from 26.4 million st in 1998 to 27.3 million st in 1999, with an estimated 1999 value of production of $143 million. These materials were used to produce structural clay products, lightweight aggregates, cement, and ceramics and refractories. Production statistics for clays and shales and for their uses in 1999 are presented.

Effects of modified Clay on the morphology and thermal stability of PMMA/clay nanocomposites

International Nuclear Information System (INIS)

Tsai, Tsung-Yen; Lin, Mei-Ju; Chuang, Yi-Chen; Chou, Po-Chiang

2013-01-01

The potential to improve the mechanical, thermal, and optical properties of poly(methyl methacrylate) (PMMA)/clay nanocomposites prepared with clay containing an organic modifier was investigated. Pristine sodium montmorillonite clay was modified using cocoamphodipropionate, which absorbs UVB in the 280–320 nm range, via ion exchange to enhance the compatibility between the clay platelets and the methyl methacrylate polymer matrix. PMMA/clay nanocomposites were synthesized via in situ free-radical polymerization. Three types of clay with various cation-exchange capacities (CEC) were used as inorganic layered materials in these organic–inorganic hybrid nanocomposites: CL42, CL120, and CL88 with CEC values of 116, 168, and 200 meq/100 g of clay, respectively. We characterized the effects of the organoclay dispersion on UV resistance, effectiveness as an O 2 gas barrier, thermal stability, and mechanical properties of PMMA/clay nanocomposites. Gas permeability analysis demonstrated the excellent gas barrier properties of the nanocomposites, consistent with the intercalated or exfoliated morphologies observed. The optical properties were assessed using UV–Visible spectroscopy, which revealed that these materials have good optical clarity, UV resistance, and scratch resistance. The effect of the dispersion capability of organoclay on the thermal properties of PMMA/clay nanocomposites was investigated by thermogravimetric analysis and differential scanning calorimetry; these analyses revealed excellent thermal stability of some of the modified clay nanocomposites. - Highlights: ► We control the dispersion morphology by protonation of K2 into the clay. ► The CL120 and CL88, with the higher CEC, are more random intercalated by K2. ► We report these materials have good optical clarity, and UV resistance

Selective Clay Placement Within a Silicate-Clay Epoxy Blend Nanocomposite

Science.gov (United States)

Miller, Sandi G (Inventor)

2013-01-01

A clay-epoxy nanocomposite may be prepared by dispersing a layered clay in an alkoxy epoxy, such as a polypropylene oxide based epoxide before combining the mixture with an aromatic epoxy to improve the nanocomposite's thermal and mechanical properties.

Thixotropic Properties of Latvian Clays

OpenAIRE

Lakevičs, Vitālijs; Stepanova, Valentīna; Ruplis, Augusts

2015-01-01

This research studies Latvia originated Devon (Tūja, Skaņkalne), quaternary (Ceplīši), Jurassic, (Strēļi) and Triassic (Vadakste) deposit clays as well as Lithuania originated Triassic (Akmene) deposit clays. Thixotropic properties of clay were researched by measuring relative viscosity of clay in water suspensions. Relative viscosity is measured with a hopper method. It was detected that, when concentration of suspension is increased, clay suspension’s viscosity also increases. It happens un...

Influence of clay environment and of corroding canister on the long-term behaviour of nuclear glasses

International Nuclear Information System (INIS)

GIn, St.

1997-01-01

This article reviews the current state of knowledge of R77 glass alteration mechanisms in the presence of the clay materials under consideration for use in an engineered barrier, and in the presence of metal canister corrosion products. These issues are addressed by a phenomenological approach and by modeling. In most cases, the codes are unable to account for the glass alteration data obtained in clay media. The main reason for this discrepancy lies in the glass alteration kinetics (a first-order law based exclusively on silicon) that do not take into account other elements including aluminum, zirconium or the rare earths, which are strongly mobilized in clay media. (author)

The contribution of tyre and brake abrasion to soot levels in streets; Beitrag des Reifen- und Bremsenabriebs zur Russemission an Strassen

Energy Technology Data Exchange (ETDEWEB)

Rauterberg-Wulff, A.

1998-09-01

After the coming into force of the new soot emission thresholds as of July 1998, excess values are measured along many city streets. The author investigated whether tyre and brake abrasion contributes to soot emissions in addition to diesel soot. For this purpose, characteristic material and physical parameters of particles of diesel soot, tyre and brake material were investigated by thermography, AAS, and SEM. With the aid of a receptor-oriented approach, the contribution of these particles to soot levels measured in a highway tunnel and a Berlin city street could be assessed. The contribution of local traffic was calculated from the difference between soot levels along the road and in a background station. The measurements inside the tunnel served to determine emissin factors for diesel soot and abrasion particles from tyres and brakes. (orig.) [Deutsch] Mit Inkrafttreten des endgueltigen Russ-Immissionswertes der 23. Verordnung zum Bundes-Immissionsschutzgesetz im Juli 1998 ist an zahlreichen innerstaedtischen Strassen mit einer Ueberschreitung dieser Werte zu rechnen. Zur Beantwortung der Frage, inwieweit neben Dieselruss auch Reifen- und Bremsenabrieb zur verkehrsbedingten Russimmission beitragen, wurden charakteristische stoffliche und physikalische Eigenschaften von Dieselruss, Reifenabrieb und Bremsenabrieb mit der Thermographie, der AAS und der Rasterelektronenmikroskopie untersucht. Mit Hilfe dieses rezeptororientierten Ansatzes konnte der Beitrag dieser Partikel zur Russimmission in einem Autobahntunnel und an einer Hauptverkehrsstrasse in Berlin bestimmt werden, wobei zuerst der Beitrag des lokalen Verkehrs zur Russimmission aus der Differenz zwischen der Russimmission an der Strassen- und einer Hintergrundstation berechnet wurde. Mit Hilfe der Messungen im Tunnel konnten Emissionsfaktoren fuer Dieselruss und fuer Reifen- und Bremsenabriebpartikel bestimmt werden. (orig.)

Fatigue Properties and Fracture Morphology of Micronised Rubber Powder (MRP) from Waste Tyres in Unfilled Elastomers

OpenAIRE

Habibah A.I.H., D; Abraham, F; Summerscales, J; Brown, P

2018-01-01

Ground rubber from waste tyres may be added to elastomers with economic and environmental benefits. The untreated or treated fillers have been investigated in different types of virgin rubber matrix. A principal concern is their crosslinked structure and large particle sizes. These additives introduce flaws leading to micro-crack initiation especially under dynamic loading. The incorporation of smaller particles at a suitable concentration may avoid deterioration in the key properties. The pr...

Clay minerals behaviour in thin sandy clay-rich lacustrine turbidites (Lake Hazar, Turkey)

Science.gov (United States)

El Ouahabi, Meriam; Hubert-Ferrari, Aurelia; Lamair, Laura; Hage, Sophie

2017-04-01

Turbidites have been extensively studied in many different areas using cores or outcrop, which represent only an integrated snapshot of a dynamic evolving flow. Laboratory experiments provide the missing relationships between the flow characteristics and their deposits. In particular, flume experiments emphasize that the presence of clay plays a key role in turbidity current dynamics. Clay fraction, in small amount, provides cohesive strength to sediment mixtures and can damp turbulence. However, the degree of flocculation is dependent on factors such as the amount and size of clay particles, the surface of clay particles, chemistry and pH conditions in which the clay particles are dispersed. The present study focuses on thin clayey sand turbidites found in Lake Hazar (Turkey) occurring in stacked thin beds. Depositional processes and sources have been previously studied and three types were deciphered, including laminar flows dominated by cohesion, transitional, and turbulence flow regimes (Hage et al., in revision). For the purpose of determine the clay behavior in the three flow regimes, clay mineralogical, geochemical measurements on the cores allow characterising the turbidites. SEM observations provide further information regarding the morphology of clay minerals and other clasts. The study is particularly relevant given the highly alkaline and saline water of the Hazar Lake. Clay minerals in Hazar Lake sediments include kaolinite (1:1-type), illite and chlorite (2:1-type). Hazar lake water is alkaline having pH around 9.3, in such alkaline environment, a cation-exchange reaction takes place. Furthermore, in saline water (16‰), salts can act as a shield and decrease the repulsive forces between clay particle surfaces. So, pH and salt content jointly impact the behaviour of clays differently. Since the Al-faces of clay structures have a negative charge in basic solutions. At high pH, all kaolinite surfaces become negative-charged, and then kaolinite

Investigation of mechanical properties of hemp/glass fiber reinforced nano clay hybrid composites

Science.gov (United States)

Unki, Hanamantappa Ningappa; Shivanand, H. K.; Vidyasagar, H. N.

2018-04-01

Over the last twenty to thirty years composite materials have been used in engineering field. Composite materials possess high strength, high strength to weight ratio due to these facts composite materials are becoming popular among researchers and scientists. The major proportion of engineering materials consists of composite materials. Composite materials are used in vast applications ranging from day-to-day household articles to highly sophisticated applications. In this paper an attempt is made to prepare three different composite materials using e-glass and Hemp. In this present investigation hybrid composite of Hemp, Glass fiber and Nano clay will be prepared by Hand-layup technique. The glass fiber used in this present investigation is E-glass fiber bi-directional: 90˚ orientation. The composite samples will be made in the form of a Laminates. The wt% of nanoclay added in the preparation of sample is 20 gm constant. The fabricated composite Laminate will be cut into corresponding profiles as per ASTM standards for Mechanical Testing. The effect of addition of Nano clay and variation of Hemp/glass fibers will be studied. In the present work, a new Hybrid composite is developed in which Hemp, E glass fibers is reinforced with epoxy resin and with Nano clay.

Fe(0)-clays interactions at 90°C under anoxic conditions: a comparative study between clay fraction of Callovo-Oxfordian and other purified clays

International Nuclear Information System (INIS)

Rivard, C.; Pelletier, M.; Villieras, F.; Barres, O.; Galmiche, M.; Ghanbaja, J.; Kohler, A.; Michau, N.

2010-01-01

Document available in extended abstract form only. In the context of the geological disposal of high-level radioactive waste it is of prime importance to understand the interactions between the saturated clay formation and steel containers. This can be achieved through an in-depth analysis of iron-clay interactions. Previous studies on the subject investigated the influence of solid/liquid ratio, iron/clay ratio, temperature and reaction time. The aim of the present study is to explain Callovo-Oxfordian-Fe(0) interactions by determining the role of each mineral phases present in the Callovo-Oxfordian (clay minerals, quartz, carbonates and pyrite) on the mechanisms of interaction between metal iron and clay particles. In that context, it is especially important to understand in detail the influence of clay nature and to obtain some insight about the relationships between interaction mechanisms at the molecular scale and crystallographic properties (particle size, TO or TOT layers, amount of edge faces...). The influence of the combination of different clays and the addition of other minerals must also be studied. In a first step, the Callovo-Oxfordian argillite from the Andra's underground research laboratory was purified to extract the clay fraction (illite, illite-smectite, kaolinite and chlorite). Batch experiments were carried out in anoxic conditions at 90 deg. C in the presence of background electrolyte (NaCl 0.02 M.L -1 , CaCl 2 0.04 M.L -1 ) for durations of one, three or nine months in the presence of metallic iron powder. Experiments without iron were used as control. The iron/clay ratio was fixed at 1/3 with a solid/liquid ratio of 1/20. The above mentioned experiments were also carried out in parallel on other purified clays: two smectites (Georgia bentonite and SWy2 from the Clay Minerals Society), one illite (illite du Puy) and one kaolinite (KGa2, from the Clay Minerals society). At the end of the experiments, solid and liquid phases were

Euroclay 95. Clays and clay materials sciences. Book of abstracts

Energy Technology Data Exchange (ETDEWEB)

Elsen, A; Grobet, P; Keung, M; Leeman, H; Schoonheydt, R; Toufar, H [eds.

1995-08-20

The document contains the abstracts of the invited lecturers (18) and posters (247) presented at EUROCLAY `95. Clays and clay materials sciences. 13 items (4 from the invited lecturers and 12 from posters) have been considered within the INIS Subject Scope and indexed separately.

Euroclay 95. Clays and clay materials sciences. Book of abstracts

International Nuclear Information System (INIS)

Elsen, A.; Grobet, P.; Keung, M.; Leeman, H.; Schoonheydt, R.; Toufar, H.

1995-01-01

The document contains the abstracts of the invited lecturers (18) and posters (247) presented at EUROCLAY '95. Clays and clay materials sciences. 13 items (4 from the invited lecturers and 12 from posters) have been considered within the INIS Subject Scope and indexed separately

Immediate emergency free anterolateral thigh flap after car-tyre friction injury: A case report with eight years follow-up

Directory of Open Access Journals (Sweden)

Abdullah Merter

2017-01-01

Full Text Available The car-tyre friction injury has differences from other injuries. The components of injury which are burn, crushing, shearing, and degloving occur. Many treatment options can be performed for coverage of wound which are Vacuum Assisted Closure system (V.A.C, skin grafting, free flaps, local flaps and cross leg flap.

Clay particles as binder for earth buildings materials: a fresh look into rheology of dense clay suspensions

Science.gov (United States)

Landrou, Gnanli; Brumaud, Coralie; Habert, Guillaume

2017-06-01

In the ceramic industry and in many sectors, clay minerals are widely used. In earthen construction technique, clay plays a crucial role in the processing. The purpose of this research is to understand and modify the clay properties in earth material to propose an innovative strategy to develop a castable earth-based material. To do so, we focused on the modification of clay properties at fresh state with inorganic additives. As the rheological behaviour of clays is controlled by their surface charge, the addition of phosphate anion allows discussing deep the rheology of concentrated clay suspensions. We highlighted the thixotropic and shear thickening behaviour of a dispersed kaolinite clay suspensions. Indeed, by adding sodium hexametaphosphate the workability of clay paste increases and the behaviour is stable during time after a certain shear is applied. Moreover, we stress that the aging and the shift in critical strain in clay system are due to the re-arrangement of clay suspension and a decrease of deformation during time. The understanding of both effect: thixotropy and aging are crucial for better processing of clay-based material and for self-compacting clay concrete. Yet, studies need to pursue to better understand the mechanism.

Optimal Design of Sheet Pile Wall Embedded in Clay

Science.gov (United States)

Das, Manas Ranjan; Das, Sarat Kumar

2015-09-01

Sheet pile wall is a type of flexible earth retaining structure used in waterfront offshore structures, river protection work and temporary supports in foundations and excavations. Economy is an essential part of a good engineering design and needs to be considered explicitly in obtaining an optimum section. By considering appropriate embedment depth and sheet pile section it may be possible to achieve better economy. This paper describes optimum design of both cantilever and anchored sheet pile wall penetrating clay using a simple optimization tool Microsoft Excel ® Solver. The detail methodology and its application with examples are presented for cantilever and anchored sheet piles. The effects of soil properties, depth of penetration and variation of ground water table on the optimum design are also discussed. Such a study will help professional while designing the sheet pile wall penetrating clay.

Clay particles as binder for earth buildings materials: a fresh look into rheology of dense clay suspensions

Directory of Open Access Journals (Sweden)

Landrou Gnanli

2017-01-01

Full Text Available In the ceramic industry and in many sectors, clay minerals are widely used. In earthen construction technique, clay plays a crucial role in the processing. The purpose of this research is to understand and modify the clay properties in earth material to propose an innovative strategy to develop a castable earth-based material. To do so, we focused on the modification of clay properties at fresh state with inorganic additives. As the rheological behaviour of clays is controlled by their surface charge, the addition of phosphate anion allows discussing deep the rheology of concentrated clay suspensions. We highlighted the thixotropic and shear thickening behaviour of a dispersed kaolinite clay suspensions. Indeed, by adding sodium hexametaphosphate the workability of clay paste increases and the behaviour is stable during time after a certain shear is applied. Moreover, we stress that the aging and the shift in critical strain in clay system are due to the re-arrangement of clay suspension and a decrease of deformation during time. The understanding of both effect: thixotropy and aging are crucial for better processing of clay-based material and for self-compacting clay concrete. Yet, studies need to pursue to better understand the mechanism.

Investigating the feasibility of a reuse scenario for textile fibres recovered from end-of-life tyres.

Science.gov (United States)

Landi, Daniele; Gigli, Silvia; Germani, Michele; Marconi, Marco

2018-05-01

The management of end-of-life tyres (ELTs) is regulated by several national and international legislations aiming to promote the recovery of materials and energy from this waste. The three main materials used in tyres are considered: rubber (main product), which is currently reused in other closed-loop applications; steel, which is used for the production of virgin materials; and textile fibres (approximately 10% by weight of ELTs), which are mainly incinerated for energy recovery (open-loop scenario). This study aims to propose and validate a new closed-loop scenario for textile fibres based on material reuse for bituminous conglomerates. The final objective is to verify the technical, environmental, financial, and economic feasibility of the proposed treatment process and reuse scenario. After characterization of the textile material, which is required to determine the technological feasibility, a specific process has been developed to clean, compact, and prepare the fibres for subsequent reuse. A life cycle assessment (LCA) has been carried out to quantify the environmental benefits of reusing the fibres. Finally, a cost benefit analysis based on the LCA results was conducted to establish the long-term financial and economic sustainability. From a technological point of view, the tyre textile fibres could be a promising substitute to the reinforcement cellulose commonly used in asphalts as long as the fibres are properly prepared (compaction and pellet production) for application in the standard bituminous conglomerate production process. From an environmental point of view, relevant benefits in terms of global warming potential and acidification potential reduction were observed in comparison with the standard incineration for energy recovery (respectively -86% and -45%). Moreover, the proposed scenario can be considered as financially viable in the medium to long term (cumulative generated cash flow is positive after the 5th year) and economically sustainable

Synthesis of templated carbons starting from clay and clay-derived zeolites for hydrogen storage applications

CSIR Research Space (South Africa)

Musyoka, Nicholas M

2014-10-01

Full Text Available 57 58 59 60 For Peer Review 1 Synthesis of templated carbons starting from clay and clay-derived zeolites for hydrogen storage applications N. M. Musyoka1*, J. Ren1, H. W. Langmi1, D. E. C. Rogers1, B. C. North1, M. Mathe1 and D. Bessarabov2... clear (filtered) extract of cloisite clay, SNC for zeolite from unfiltered cloisite clay extract and SBC for zeolite from unfiltered South African bentonite clay extract. Furfuryl alcohol (Sigma Aldrich, C5H6O2, 98%) and Ethylene gas were used...

R7T7 nuclear waste glass behavior in moist clay: role of the clay mass/glass surface area ratio

International Nuclear Information System (INIS)

Godon, N.; Vernaz, E.

1989-01-01

R7T7 glass alteration was investigated in the presence of various moist clays. In contact with smectite 4a, selected in France as a potential engineered barrier material, the glass was significantly corroded: after 6 months the glass corrosion rate was practically the same as the initial alteration rate in double-distilled water. Substantially lower alteration was observed in contact with bentonite 6 activated by sodium carbonate. Smectite 4a consumes silicon released by glass corrosion, and thus retards the rise to high silicon concentrations in solution at which the glass corrosion rate diminishes. Glass can therefore in some cases be altered as much in moist clay as in water with high renewal rates. Other experiments with smaller quantities of smectite 4a showed that the phenomenon becomes less important in time: its duration is proportional to the ratio between the clay mass (C) and the glass surface area (SA). Comparing the results of studies at different C/SA ratios indicates that low glass corrosion rates are obtained more slowly at higher C/SA ratios. Tests with 239 Pu-doped R7T7 glass also showed that the radionuclide retention factor in the alteration film at the glass surface is only 6, compared with a factor of nearly 50 in double-distilled water

Clay stabilization by using gypsum and paddy husk ash with reference to UCT and CBR value

Science.gov (United States)

Roesyanto; Iskandar, R.; Hastuty, I. P.; Dianty, W. O.

2018-02-01

Clays that have low shear strength need to be stabilized in order to meet the technical requirements to serve as a subgrade material. One of the usual soil stabilization methods is by adding chemicals such as Portland cement, lime, and bitumen. The clay stabilization research was done by adding gypsum and paddy husk ash. The research goals were to find out the value of engineering properties of clay due to the addition of 2% gypsum and 2% - 15% paddy husk ash. The soil was classified as Clay - Low Plasticity (CL) based on USCS and was classified as A-7-6 (10) based on AASHTO classification system. The UCT value of original soil was 1.41 kg/cm2. While the CBR soaked and unsoaked values of original soil were 4.41% and 6.23% respectively. The research results showed the addition of paddy husk ash decreased the value of unconfined compressive strength as well as CBR. The stabilized soil by 2% gypsum and 0% paddy husk ash gave maximum UCT value of 1.67 kg/cm2, while the maximum value of CBR were found 6.71% for CBR soaked and 8.00% for CBR unsoaked. The addition of paddy husk ash did not alter the soil classification according to AASHTO or USCS, even degrade the engineering properties of original soil.

Research of Deformation of Clay Soil Mixtures Mixtures

OpenAIRE

Romas Girkontas; Tadas Tamošiūnas; Andrius Savickas

2014-01-01

The aim of this article is to determine clay soils and clay soils mixtures deformations during drying. Experiments consisted from: a) clay and clay mixtures bridges (height ~ 0,30 m, span ~ 1,00 m); b) tiles of clay and clay, sand and straw (height, length, wide); c) cylinders of clay; clay and straw; clay, straw and sand (diameter; height). According to the findings recommendations for clay and clay mixtures drying technology application were presented. During the experiment clay bridge bear...

Coupled modelling (transport-reaction) of the fluid-clay interactions and their feed back on the physical properties of the bentonite engineered clay barrier system; Modelisation couplee (transport - reaction) des interactions fluides - argiles et de leurs effets en retour sur les proprietes physiques de barrieres ouvragees en bentonite

Energy Technology Data Exchange (ETDEWEB)

Marty, N

2006-11-15

The originality of this work is to process feed back effects of mineralogical and chemical modifications of clays, in storage conditions, on their physical properties and therefore on their transport characteristics (porosity, molecular diffusion, permeability). These feed back effects are modelled using the KIRMAT code (Kinetic of Reaction and MAss Transfer) developed from the kinetic code KINDIS by adding the effect of water renewal in the mineral-solution reactive cells. KIRMAT resolves mass balance equations associated with mass transport together with the geochemical reactions in a 1D approach. After 100 000 years of simulated interaction at 100 C, with the fluid of the Callovo-Oxfordian geological level (COX) and with iron provided by the steel overpack corrosion, the montmorillonite of the clay barrier is only partially transformed (into illite, chlorite, saponite...). Only outer parts of the modelled profile seem to be significantly affected by smectite dissolution processes, mainly at the interface with the geological environment. The modifications of physical properties show a closure of the porosity at the boundaries of the barrier, by creating a decrease of mass transport by molecular diffusion, essentially at the interface with the iron. Permeability laws applied to this system show a decrease of the hydraulic conductivity correlated with the porosity evolution. Near the COX, the swelling pressure of the clays from the barrier decreases. In the major part of the modelled profile, the engineered clay barrier system seems to keep its initial physical properties (porosity, molecular diffusion, permeability, swelling pressure) and functionalities. (author)

HDPE/clay hybrids: the effect of clay modified with poly(diphenyl siloxanes) on thermal and rheological properties

Energy Technology Data Exchange (ETDEWEB)

Monasterio, Fernanda E.; Carrera, Maria C.; Erdmann, Eleonora; Destefanis, Hugo A., E-mail: ferelenakq@gmail.co [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina). Inst. de Investigaciones para la Industria Quimica; Pita, Victor J.R.R.; Dias, Marcos L. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Profa. Eloisa Mano

2009-07-01

Poly(diphenyl siloxanes) (PDPhS) were synthesized in presence of organophilic clay in order to modify its nano structure. Two silane monomers were used: dimethoxydiphenylsilane and dichlorodiphenylsilane. The following characterizations were performed for all clays: XRD, FTIR and TGA/DTG. These siloxane-modified clays were more hydrophobic and had enhanced thermal stability. Solvent extraction was carried out in the siloxane-modified clays and the PDPhS soluble fraction analyzed according the molecular weight via GPC. The presence of free and grafted oligomers on clay surface was identified. The modified clays were added to HDPE by melt processing to obtain HDPE/clay hybrids which exhibited marked differences in the rheological behavior when compared with neat HDPE. (author)

HDPE/clay hybrids: the effect of clay modified with poly(diphenyl siloxanes) on thermal and rheological properties

International Nuclear Information System (INIS)

Monasterio, Fernanda E.; Carrera, Maria C.; Erdmann, Eleonora; Destefanis, Hugo A.; Pita, Victor J.R.R.; Dias, Marcos L.

2009-01-01

Poly(diphenyl siloxanes) (PDPhS) were synthesized in presence of organophilic clay in order to modify its nano structure. Two silane monomers were used: dimethoxydiphenylsilane and dichlorodiphenylsilane. The following characterizations were performed for all clays: XRD, FTIR and TGA/DTG. These siloxane-modified clays were more hydrophobic and had enhanced thermal stability. Solvent extraction was carried out in the siloxane-modified clays and the PDPhS soluble fraction analyzed according the molecular weight via GPC. The presence of free and grafted oligomers on clay surface was identified. The modified clays were added to HDPE by melt processing to obtain HDPE/clay hybrids which exhibited marked differences in the rheological behavior when compared with neat HDPE. (author)

Immobilisation of shredded waste in a cement matrix

International Nuclear Information System (INIS)

James, J.M.; Smith, D.L.

1987-10-01

The work covered in the period of this report was aimed at proving the infilling capabilities of waste packages containing shredded paper and plastic simulant waste material held in a basket. The programme required the production of 200 and 500 litre packages and a demonstration that infilling could be attained to give a minimum of voidage in the completed cemented product. The procurement, testing and fitting of level detectors was an important part of this work to demonstrate a means of controlling the process to prevent overfilling of the packages. Evaluation of full-scale cemented products was required to confirm previously reported properties of density and homogeneity in packages produced by the reference encapsulation process and to demonstrate package integrity under sea-disposal conditions. A standard feedstock for the continuity of a long-term programme was required. Such a product, based on an analysis of arisings from plutonium gloveboxes, was produced in bulk and characterised. The previously observed movement of waste during infilling, due to its low density compared with that of the infill grout, required further assessment. During the period, 200, 400 and 500 litre drums required for future active infilling trials were modified and despatched to AERE Harwell for waste loading. These drums were fitted with level detectors and with grout spreader troughs which had been identified during the development programme. A prototype automated Grout Infill Test Rig designed by BNF plc was delivered to Winfrith towards the end of the period for practical assessment trials. (author)

Admixing dredged marine clay with cement-bentonite for reduction of compressibility

Science.gov (United States)

Rahilman, Nur Nazihah Nur; Chan, Chee-Ming

2017-11-01

Cement-based solidification/stabilization is a method that is widely used for the treatment of dredged marine clay. The key objective for solidification/stabilization is to improve the engineering properties of the originally soft, weak material. Dredged materials are normally low in shear strength and bearing capacity while high incompressibility. In order to improve the material's properties for possible reuse, a study on the one-dimensional compressibility of lightly solidified dredged marine clay admixed with bentonite was conducted. On the other hand, due to the viscous nature, particularly the swelling property, bentonite is a popular volumising agent for backfills. In the present study, standard oedometer test was carried out to examine the compressibility of the treated sample. Complementary strength measurements were also conducted with laboratory vane shear setup on both the untreated and treated dredged marine clay. The results showed that at the same binder content, the addition of bentonite contributed significantly to the reduction of compressibility and rise in undrained shear strength. These improved properties made the otherwise discarded dredged marine soils potentially reusable for reclamation works, for instance.

Immediate emergency free anterolateral thigh flap after car-tyre friction injury: A case report with eight years follow-up.

Science.gov (United States)

Merter, Abdullah; Armangil, Mehmet; Kaya, Burak; Bilgin, Sinan

2017-01-01

The car-tyre friction injury has differences from other injuries. The components of injury which are burn, crushing, shearing, and degloving occur. Many treatment options can be performed for coverage of wound which are Vacuum Assisted Closure system (V.A.C), skin grafting, free flaps, local flaps and cross leg flap. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Crystallite size distribution of clay minerals from selected Serbian clay deposits

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Simić Vladimir

2006-01-01

Full Text Available The BWA (Bertaut-Warren-Averbach technique for the measurement of the mean crystallite thickness and thickness distributions of phyllosilicates was applied to a set of kaolin and bentonite minerals. Six samples of kaolinitic clays, one sample of halloysite, and five bentonite samples from selected Serbian deposits were analyzed. These clays are of sedimentary volcano-sedimentary (diagenetic, and hydrothermal origin. Two different types of shape of thickness distribution were found - lognormal, typical for bentonite and halloysite, and polymodal, typical for kaolinite. The mean crystallite thickness (T BWA seams to be influenced by the genetic type of the clay sample.

Project Opalinus clay Zuercher Weinland of Nagra. Evaluation of the geo-scientific data base and of the construction engineering aspects; Projekt Opalinuston Zuercher Weinland der Nagra. Beurteilung der erdwissenschaftlichen Datengrundlagen und der bautechnischen Machbarkeit

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-02-15

In this report the Commission for Nuclear Waste Management (KNE) assesses the geological and engineering aspects of the project Opalinus Clay, in which Nagra demonstrates the postclosure safety of geological disposal of spent fuel (SF), vitrified high-level wastes (HLW) and intermediate-level wastes (ILW) in a repository in the Opalinus Clay of the Zuercher Weinland in northern Switzerland. After in-depth examination of the geological database, KNE concludes that the demonstration of a suitable geological site for final disposal of SF, HLW and ILW in the Opalinus Clay of the Zuercher Weinland has been achieved. The geological assumptions Nagra uses for the assessment of long-term safety are based on data that have been carefully collected and interpreted. KNE acknowledges that Nagra interpreted the geological data correctly and adequately using state-of-the-art techniques. In case of lacking information, Nagra has used conservative or worst-case assumptions. The information documented by Nagra represents a good synthesis of field, laboratory and literature data. The tectonic situation of the Zuercher Weinland was examined in great details by Nagra. In the centre of the investigated region, where the Opalinus Clay occurs at 600 to 750 meters depth, the 3D-seismic data confirm its undisturbed stratification in an area of about 15 km{sup 2}. Analysis and interpretation of the available information on the geological evolution provides no indication that erosion would expose the confining units above the Opalinus Clay within the next million years. The Opalinus Clay in the Zuercher Weinland is quite homogeneous and about 110 m thick. The properties of this rock are examined and found to be favourable for a repository. The dominance of the fine grain size and the high clay content indicate a very low hydraulic conductivity suitable for the isolation of radioactive wastes. Pore water extracted from drill-core samples is saline and has remained trapped for millions of

Aspects of clay/concrete interactions

International Nuclear Information System (INIS)

Oscarson, D.W.; Dixon, D.A.; Onofrei, M.

1997-01-01

In the Canadian concept for nuclear fuel waste management, both clay-based materials and concrete are proposed for use as barriers, seals or supporting structures. The main concern when clays and concrete are in proximity is the generation of a high-pH environment by concrete since clay minerals are relatively unstable at high pH. Here we examine the OH - -generating capacity of two high-performance concretes when in contact with several solutions. We also investigate various aspects of claylconcrete interactions. They are: (1) the alkalimetric titration of clay suspensions, (2) the effect of Ca(OH) 2 (portlandite) on the swelling and hydraulic properties of compacted bentonite, and (3) the influence of cement grout on a backfill clay retrieved from the 900-d Buffer/Container Experiment at the Underground Research Laboratory of AECL. The results indicate that although high-performance concretes establish significantly lower poresolution pH (9 to 10) than does ordinary portland cement, the pH is still somewhat higher than that of clay/groundwater systems of about pH 8. Hence, even if high-performance concrete is used in a disposal vault, the potential still exists for clay minerals to alter over long periods of time if in contact with this concrete. The data show, however, that clays have a substantial buffering capacity, and clay-based barriers can thus neutralize much of the OH - potentially released from concrete in a vault. Moreover, even after reacting for 120 d at 85 o C with up to 5 wt.% Ca(OH) 2 , compacted bentonite (dry density = 1.2 Mg/m 3 ) retains much of its swelling capacity and has a permeability low enough (hydraulic conductivity ≤ 10 -11 m/s) to ensure that molecular diffusion will be the main transport mechanism through compacted clay-based barriers. Furthermore, according to X-ray diffractometry, the clay mineral component of backfill was not altered by contact with a cement grout for 900 d in the Buffer/Container Experiment

Physical Properties of Latvian Clays

OpenAIRE

Jurgelāne, I; Stepanova, V; Ločs, J; Mālers, J; Bērziņa-Cimdiņa, L

2012-01-01

Physical and chemical properties of clays mostly depends on its mineral and chemical composition, particle size and pH value. The mutual influence of these parameters is complex. Illite is the most abundant clay mineral in Latvia and usually used in building materials and pottery. The viscosity and plasticity of Latvian clays from several deposits were investigated and correlated with mineral composition, particle size and pH value. Fractionated and crude clay samples were used. The p...

Adsorption of Dissolved Gases (CH4, CO2, H2, Noble Gases) by Water-Saturated Smectite Clay Minerals

Science.gov (United States)

Bourg, I. C.; Gadikota, G.; Dazas, B.

2016-12-01

Adsorption of dissolved gases by water-saturated clay minerals plays important roles in a range of fields. For example, gas adsorption in on clay minerals may significantly impact the formation of CH4 hydrates in fine-grained sediments, the behavior of CH4 in shale, CO2 leakage across caprocks of geologic CO2 sequestration sites, H2 leakage across engineered clay barriers of high-level radioactive waste repositories, and noble gas geochemistry reconstructions of hydrocarbon migration in the subsurface. Despite its importance, the adsorption of gases on clay minerals remains poorly understood. For example, some studies have suggested that clay surfaces promote the formation of CH4 hydrates, whereas others indicate that clay surfaces inhibit the formation of CH4 hydrates. Here, we present molecular dynamics (MD) simulations of the adsorption of a range of gases (CH4, CO2, H2, noble gases) on clay mineral surfaces. Our results indicate that the affinity of dissolved gases for clay mineral surfaces has a non-monotone dependence on the hydrated radius of the gas molecules. This non-monotone dependence arises from a combination of two effects: the polar nature of certain gas molecules (in particular, CO2) and the templating of interfacial water structure by the clay basal surface, which results in the presence of interfacial water "cages" of optimal size for intermediate-size gas molecules (such as Ne or Ar).

Prediction of the residual strength of clay using functional networks

Directory of Open Access Journals (Sweden)

S.Z. Khan

2016-01-01

Full Text Available Landslides are common natural hazards occurring in most parts of the world and have considerable adverse economic effects. Residual shear strength of clay is one of the most important factors in the determination of stability of slopes or landslides. This effect is more pronounced in sensitive clays which show large changes in shear strength from peak to residual states. This study analyses the prediction of the residual strength of clay based on a new prediction model, functional networks (FN using data available in the literature. The performance of FN was compared with support vector machine (SVM and artificial neural network (ANN based on statistical parameters like correlation coefficient (R, Nash--Sutcliff coefficient of efficiency (E, absolute average error (AAE, maximum average error (MAE and root mean square error (RMSE. Based on R and E parameters, FN is found to be a better prediction tool than ANN for the given data. However, the R and E values for FN are less than SVM. A prediction equation is presented that can be used by practicing geotechnical engineers. A sensitivity analysis is carried out to ascertain the importance of various inputs in the prediction of the output.

Enchanted Clays: 44th Annual Meeting of the Clay Minerals Society (June 2007)

Energy Technology Data Exchange (ETDEWEB)

Randall T. Cygan

2007-06-01

“Enchanted Clays: 44th Annual Meeting of the Clay Minerals Society” was held in early June 2007 in beautiful and historic Santa Fe, New Mexico, USA. Santa Fe provided an idyllic location in the southwestern United States for the attendees to enjoy technical and social sessions while soaking up the diverse culture and wonderful climate of New Mexico—The Land of Enchantment. The meeting included a large and varied group of scientists, sharing knowledge and ideas, benefitting from technical interactions, and enjoying the wonderful historic and enchanted environs of Santa Fe. Including significant number of international scientists, the meeting was attended by approximately two hundred participants. The meeting included three days of technical sessions (oral and poster presentations), three days of field trips to clay and geological sites of northern New Mexico, and a full day workshop on the stabilization of carbon by clays. Details can be found at the meeting web site: www.sandia.gov/clay.

Evaluation of the bleaching flux in clays containing hematite and different clay minerals

International Nuclear Information System (INIS)

Silva Junior, E.M.; Lusa, T.; Silva, T.M.; Medeiros, B.B.; Santos, G.R. dos; Morelli, M.R.

2016-01-01

Previous studies have shown that the addition of a synthetic flux in a clay mineral constituted by illite phase in the presence of iron oxide with the hematite, promotes color change of the firing products, making the reddish color firing into whiteness. This flow is constituted of a vitreous phase of the silicates family obtained by fusion/solidification of oxides and carbonates. Thus, the objective of this work was that of studying the interaction of the iron element in the final color mechanism of the different types of mineral crystal phase of the clays. In order to study the phenomenon, we obtained different compositions between the select clays and the synthetic flow, and characterization using X-ray diffraction (XRD) and visual analysis. The results showed that the action of the synthetic flow as a modifying agent for color depends on the mineral crystal phase of the clays. The color firing modification does not occur in the clays content high levels of kaolinite mineral phase. (author)

Columns in Clay

Science.gov (United States)

Leenhouts, Robin

2010-01-01

This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

Flocculation of Clay Colloids Induced by Model Polyelectrolytes: Effects of Relative Charge Density and Size.

Science.gov (United States)

Sakhawoth, Yasine; Michot, Laurent J; Levitz, Pierre; Malikova, Natalie

2017-10-06

Flocculation and its tuning are of utmost importance in the optimization of several industrial protocols in areas such as purification of waste water and civil engineering. Herein, we studied the polyelectrolyte-induced flocculation of clay colloids on a model system consisting of purified clay colloids of well-defined size fractions and ionene polyelectrolytes presenting regular and tunable chain charge density. To characterize ionene-induced clay flocculation, we turned to the combination of light absorbance (turbidity) and ζ-potential measurements, as well as adsorption isotherms. Our model system allowed us to identify the exact ratio of positive and negative charges in clay-ionene mixtures, the (c+/c-) ratio. For all samples studied, the onset of efficient flocculation occurred consistently at c+/c- ratios significantly below 1, which indicated the formation of highly ionene-deficient aggregates. At the same time, the ζ-potential measurements indicated an apparent zero charge on such aggregates. Thus, the ζ-potential values could not provide the stoichiometry inside the clay-ionene aggregates. The early onset of flocculation in clay-ionene mixtures is reminiscent of the behavior of multivalent salts and contrasts that of monovalent salts, for which a large excess amount of ions is necessary to achieve flocculation. Clear differences in the flocculation behavior are visible as a function of the ionene charge density, which governs the conformation of the ionene chains on the clay surface. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of Different Types of Clays and Maleic Anhydride Modified Polystyrene on Polystyrene/Clay Nanocomposites

Directory of Open Access Journals (Sweden)

M. Mehrabzadeh

2013-01-01

Full Text Available Polymer/clay nanocomposites are considered as a new subject of research in Iran and the world. Addition of a minimum amount of clay (2-5wt% can improve the mechanical properties, enhance barrier properties and reduce flammability dramatically. Polystyrene (PS exhibits high strength, high modulus and excellent dimensional stability, but it has poor ductility, elongation, and flexural modulus. By incorporating clay into polystyrene these properties can be improved. In this study preparation of polystyrene/clay nanocomposite, effects of different types of clays (Cloisite 10A andNanomer I.30TC and maleic anhydride modified polystyrene on mechanical properties of the prepared polystyrene/clay nanocomposites were evaluated. Samples were prepared by a twin screw extruder. Transmission electron microscopy (TEM and X-ray diffraction (XRD techniques were employed to evaluate the extent of intercalation and exfoliation of silicate layers in the nanocomposites. Mechanical tests show that by addition of clay and maleic anhydride modified polystyrene the flexural modulus (~30% and elongation-at-break (~40% of prepared nanocomposites have been improved. XRD and TEM results show that nanocomposite have an intercalated structure with ability to change to further exfoliation structure.

Transmission X-ray Microscopy—A New Tool in Clay Mineral Floccules Characterization

Directory of Open Access Journals (Sweden)

Ray L. Frost

2012-10-01

Full Text Available Effective flocculation and dewatering of mineral processing streams containing clays are microstructure dependent in clay-water systems. Initial clay flocculation is crucial in the design and for the development of a new methodology of gas exploitation. Microstructural engineering of clay aggregates using covalent cations and Keggin macromolecules have been monitored using the new state of the art Transmission X-ray Microscope (TXM with 60 nm tomography resolution installed in a Taiwanese synchrotron. The 3-D reconstructions from TXM images show complex aggregation structures in montmorillonite aqueous suspensions after treatment with Na+, Ca2+ and Al13 Keggin macromolecules. Na-montmorillonite displays elongated, parallel, well-orientated and closed-void cellular networks, 0.5–3 µm in diameter. After treatment by covalent cations, the coagulated structure displays much smaller, randomly orientated and openly connected cells, 300–600 nm in diameter. The average distances measured between montmorillonite sheets was around 450 nm, which is less than half of the cell dimension measured in Na-montmorillonite. The most dramatic structural changes were observed after treatment by Al13 Keggin; aggregates then became arranged in compacted domains of a 300 nm average diameter composed of thick face-to-face oriented sheets, which forms porous aggregates with larger intra-aggregate open and connected voids.

Evaluation of impact strength of polyamide 6/bentonite clay nanocomposites

International Nuclear Information System (INIS)

Paz, Rene A.; Leite, Amanda M.D.; Medeirosa, Vanessa da N.; Araujo, Edcleide M.; Melo, Tomas J.A.; Pessan, Luiz A.

2010-01-01

Nanocomposites of polymer/clay have had much attention in recent years, particularly those developed with layered silicates due to the need of engineering materials more efficient than pure polymers for certain applications. The level of exfoliation of layered silicates in crystalline structure of polymer matrices has been studied and has been observed that they affect the crystalline behavior and the physical and mechanical properties. In this study, nanocomposites of polyamide 6 were obtained by the melt intercalation method, using a regional bentonite modified with a quaternary ammonium salt in an amount of 3% by weight. XRD results showed that incorporation of salt among the layers of clay, making it organophilic and obtaining exfoliated and/or partially exfoliated structures. The impact properties of the nanocomposites showed inferior in relation to pure polyamide, in other words, lost of toughness. (author)

Clay Generic Disposal System Model - Sensitivity Analysis for 32 PWR Assembly Canisters (+2 associated model files).

Energy Technology Data Exchange (ETDEWEB)

Morris, Edgar [Argonne National Lab. (ANL), Argonne, IL (United States)

2014-10-01

The Used Fuel Disposition Campaign (UFDC), as part of the DOE Office of Nuclear Energy’s (DOE-NE) Fuel Cycle Technology program (FCT) is investigating the disposal of high level radioactive waste (HLW) and spent nuclear fuela (SNF) in a variety of geologic media. The feasibility of disposing SNF and HLW in clay media has been investigated and has been shown to be promising [Ref. 1]. In addition the disposal of these wastes in clay media is being investigated in Belgium, France, and Switzerland. Thus, Argillaceous media is one of the environments being considered by UFDC. As identified by researchers at Sandia National Laboratory, potentially suitable formations that may exist in the U.S. include mudstone, clay, shale, and argillite formations [Ref. 1]. These formations encompass a broad range of material properties. In this report, reference to clay media is intended to cover the full range of material properties. This report presents the status of the development of a simulation model for evaluating the performance of generic clay media. The clay Generic Disposal System Model (GDSM) repository performance simulation tool has been developed with the flexibility to evaluate not only different properties, but different waste streams/forms and different repository designs and engineered barrier configurations/ materials that could be used to dispose of these wastes.

Thixotropic Properties of Latvian Illite Containing Clays

OpenAIRE

Lakevičs, Vitālijs; Stepanova, Valentīna; Niedra, Santa; Dušenkova, Inga; Ruplis, Augusts

2015-01-01

Thixotropic properties of Latvian Devonian and Quaternary clays were studied. Dynamic viscosity of the water clay suspensions were measured with a rotating viscometer. Influence of concentration, pH and modifiers on the thixotropic clay properties was analyzed. It was found that Latvian clays have thixotropic properties. Stability of clay suspensions is described with the thixotropy hysteresis loop. Increasing the speed of the viscometer rotation, dynamic viscosity of the clay suspension decr...

Clay exfoliation and polymer/clay aerogels by supercritical carbon dioxide

Directory of Open Access Journals (Sweden)

Simona eLongo

2013-11-01

Full Text Available Supercritical carbon dioxide (scCO2 treatments of a montmorillonite (MMT intercalated with ammonium cations bearing two long hydrocarbon tails (organo-modified MMT, OMMT led to OMMT exfoliation, with loss of the long-range order in the packing of the hydrocarbon tails and maintenance of the long-range order in the clay layers. The intercalated and the derived exfoliated OMMT have been deeply characterized, mainly by X-ray diffraction analyses. Monolithic composite aerogels, with large amounts of both intercalated and exfoliated OMMT and including the nanoporous-crystalline δ form of syndiotactic polystyrene (s-PS, have been prepared, by scCO2 extractions of s-PS-based gels. Also for high OMMT content, the gel and aerogel preparation procedures occur without re-aggregation of the exfoliated clay, which is instead observed for other kinds of polymer processing. Aerogels with the exfoliated OMMT have more even dispersion of the clay layers, higher elastic modulus and larger surface area than aerogels with the intercalated OMMT. Extremely light materials with relevant transport properties could be prepared. Moreover, s-PS-based aerogels with exfoliated OMMT could be helpful for the handling of exfoliated clay minerals.

What makes a natural clay antibacterial?

Science.gov (United States)

Williams, Lynda B.; Metge, David W.; Eberl, Dennis D.; Harvey, Ronald W.; Turner, Amanda G.; Prapaipong, Panjai; Port-Peterson, Amisha T.

2011-01-01

Natural clays have been used in ancient and modern medicine, but the mechanism(s) that make certain clays lethal against bacterial pathogens has not been identified. We have compared the depositional environments, mineralogies, and chemistries of clays that exhibit antibacterial effects on a broad spectrum of human pathogens including antibiotic resistant strains. Natural antibacterial clays contain nanoscale (2+ solubility.

Mechanical properties of biocompatible clay/P(MEO2MA-co-OEGMA) nanocomposite hydrogels.

Science.gov (United States)

Xiang, Hengxue; Xia, Mengge; Cunningham, Alexander; Chen, Wei; Sun, Bin; Zhu, Meifang

2017-08-01

The effects of crosslinking density, polymer concentration and monomer ratio on the mechanical properties (tensile and compressive properties) of biocompatible clay/P(MEO 2 MA-co-OEGMA) nanocomposite (NC) hydrogels were investigated. These novel NC hydrogels, composed of inorganic/organic networks, were prepared via in-situ free radical polymerization. The results showed that with increasing inorganic crosslinking agent, i.e. clay concentration, an increase in the tensile strength, elongation at break and compressive strength was observed. Similarly, with increasing polymer concentration, the tensile strength and compressive strength of the NC hydrogels increased while the elongation at break decreased. Increasing the molar concentration of OEGMA in the comonomer led to an increase in the tensile strength of the NC hydrogels but a reduction in the compressive strength. Moreover, clay/P(MEO 2 MA-co-OEGMA) NC hydrogels presented good biocompatibility bolstering their application as tissue engineering scaffolds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Clay Portrait Boxes

Science.gov (United States)

Wilbert, Nancy Corrigan

2009-01-01

In an attempt to incorporate sculptural elements into her ceramics program, the author decided to try direct plaster casting of the face to make a plaster mold for clay. In this article, the author shares an innovative ceramics lesson that teaches students in making plaster casts and casting the face in clay. This project gives students the…

Clay matrix voltammetry

International Nuclear Information System (INIS)

Perdicakis, Michel

2012-01-01

Document available in extended abstract form only. In many countries, it is planned that the long life highly radioactive nuclear spent fuel will be stored in deep argillaceous rocks. The sites selected for this purpose are anoxic and satisfy several recommendations as mechanical stability, low permeability and low redox potential. Pyrite (FeS 2 ), iron(II) carbonate, iron(II) bearing clays and organic matter that are present in very small amounts (about 1% w:w) in soils play a major role in their reactivity and are considered today as responsible for the low redox potential values of these sites. In this communication, we describe an electrochemical technique derived from 'Salt matrix voltammetry' and allowing the almost in-situ voltammetric characterization of air-sensitive samples of soils after the only addition of the minimum humidity required for electrolytic conduction. Figure 1 shows the principle of the developed technique. It consists in the entrapment of the clay sample between a graphite working electrode and a silver counter/quasi-reference electrode. The sample was previously humidified by passing a water saturated inert gas through the electrochemical cell. The technique leads to well-defined voltammetric responses of the electro-active components of the clays. Figure 2 shows a typical voltammogram relative to a Callovo-Oxfordian argillite sample from Bure, the French place planned for the underground nuclear waste disposal. During the direct scan, one can clearly distinguish the anodic voltammetric signals for the oxidation of the iron (II) species associated with the clay and the oxidation of pyrite. The reverse scan displays a small cathodic signal for the reduction of iron (III) associated with the clay that demonstrates that the majority of the previously oxidized iron (II) species were transformed into iron (III) oxides reducible at lower potentials. When a second voltammetric cycle is performed, one can notice that the signal for iron (II

Investigation on the cohesive silt/clay-particle sediment via the coupled CFD-DEM simulations

Science.gov (United States)

Xu, S.; Sun, H.; Sun, R.

2017-12-01

Sedimentation of silt/clay particles happens ubiquitously in nature and engineering field. There have been abundant studies focusing on the settling velocity of the cohesive particles, while studies on the sediment deposited from silt/clay irregular particles, including the vertical concentration profile of sediment and the various forces among the deposited particles are still lacking. This paper aims to investigate the above topics by employing the CFD-DEM (Computational Fluid Dynamics-Discrete Element Method) simulations. In this work, we simulate the settling of the mono- and poly- dispersed silt/clay particles and mainly study the characteristics of the deposited cohesive sediment. We use the bonded particles to simulate the irregular silt/clay aggregates at the initial state and utilize the van der Waals force for all micro-particles to consider the cohesive force among silt/clay particles. The interparticle collision force and the fluid-particle interaction forces are also considered in our numerical model. The value of the mean structural density of cohesive sediment obtained from simulations is in good agreement with the previous research, and it is obviously smaller than no-cohesive sediment because of the existence of the silt/clay flocs. Moreover, the solid concentration of sediment increases with the growth of the depth. It is because the silt/clay flocs are more easily to break up due to the gradually increased submerged gravity of the deposited particles along the depth. We also obtain the noncontacted cohesive force and contact force profiles during the sedimentation and the self-weight consolidation process. The study of the concentration profile and the forces among silt/clay sediment will help to give an accurate initial condition for calculating the speed of the reconsolidation process by employing the artificial loads, which is necessary for practical designs of the land reclamation projects.

Kalman and particle filtering methods for full vehicle and tyre identification

Science.gov (United States)

Bogdanski, Karol; Best, Matthew C.

2018-05-01

This paper considers identification of all significant vehicle handling dynamics of a test vehicle, including identification of a combined-slip tyre model, using only those sensors currently available on most vehicle controller area network buses. Using an appropriately simple but efficient model structure, all of the independent parameters are found from test vehicle data, with the resulting model accuracy demonstrated on independent validation data. The paper extends previous work on augmented Kalman Filter state estimators to concentrate wholly on parameter identification. It also serves as a review of three alternative filtering methods; identifying forms of the unscented Kalman filter, extended Kalman filter and particle filter are proposed and compared for effectiveness, complexity and computational efficiency. All three filters are suited to applications of system identification and the Kalman Filters can also operate in real-time in on-line model predictive controllers or estimators.

Energy dispersive X-ray fluorescence from useless tyres samples with a Si PIN detector; Fluorescencia de raios X por dispersao em energia de amostras de pneus inserviveis com detector de Si-PIN

Energy Technology Data Exchange (ETDEWEB)

Lopes, Fabio; Scheibel, Viviane [Universidade Estadual de Londrina, PR (Brazil). Dept. de Fisica. Lab. de Fisica Nuclear Aplicada]. E-mail: bonn@uel.br; Melquiades, Fabio Luiz [Universidade Estadual do Centro-Oeste, Guarapuava, PR (Brazil). Dept. de Fisica; Moraes, Liz Mary Bueno de [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear

2005-07-01

The concentration of Zn from discard tyre samples is of environmental interest, since on its production are used S for the rubber vulcanization process, and Zn O as reaction catalyze. The useless tyres are been used for asphalt pave, burn in cement industry and thermoelectric power plant and in erosion control of agriculture areas. Analyses of these samples requires frequently chemical digestion that is expensive and take a long time. Trying to eliminate these limitations, the objective of this work was use Energy Dispersive X Ray Fluorescence technique (EDXRF) with a portable system as the technique is multi elementary and needs a minimum sample preparation. Five useless tyres samples were grind in a knife mill and after this in a cryogenic mill, and analyzed in pellets form, using a X ray mini tube (Ag target, Mo {sub l}ter, 25 kV/20 {sub A}) for 200 s and a Si-PIN semiconductor detector coupled to a multichannel analyzer. Were obtained Zn concentrations in the range of 40.6 to 44.2 {sub g} g{sub 1}, representing nearly 0.4. (author)

Steam gasification of waste tyre: Influence of process temperature on yield and product composition

Energy Technology Data Exchange (ETDEWEB)

Portofino, Sabrina, E-mail: sabrina.portofino@enea.it [UTTP NANO – C.R. ENEA Portici, P.le E. Fermi, 1 Loc. Granatello, 80055 Portici (Italy); Donatelli, Antonio; Iovane, Pierpaolo; Innella, Carolina; Civita, Rocco; Martino, Maria; Matera, Domenico Antonio; Russo, Antonio; Cornacchia, Giacinto [UTTTRI RIF – C.R. ENEA Trisaia, SS Jonica 106, km 419.5, 75026 Rotondella (Italy); Galvagno, Sergio [UTTP NANO – C.R. ENEA Portici, P.le E. Fermi, 1 Loc. Granatello, 80055 Portici (Italy)

2013-03-15

Highlights: ► Steam gasification of waste tyre as matter and energy recovery treatment. ► Process temperature affects products yield and gas composition. ► High temperature promotes hydrogen production. ► Char exploitation as activated carbon or carbon source. - Abstract: An experimental survey of waste tyre gasification with steam as oxidizing agent has been conducted in a continuous bench scale reactor, with the aim of studying the influence of the process temperature on the yield and the composition of the products; the tests have been performed at three different temperatures, in the range of 850–1000 °C, holding all the other operational parameters (pressure, carrier gas flow, solid residence time). The experimental results show that the process seems promising in view of obtaining a good quality syngas, indicating that a higher temperature results in a higher syngas production (86 wt%) and a lower char yield, due to an enhancement of the solid–gas phase reactions with the temperature. Higher temperatures clearly result in higher hydrogen concentrations: the hydrogen content rapidly increases, attaining values higher than 65% v/v, while methane and ethylene gradually decrease over the range of the temperatures; carbon monoxide and dioxide instead, after an initial increase, show a nearly constant concentration at 1000 °C. Furthermore, in regards to the elemental composition of the synthesis gas, as the temperature increases, the carbon content continuously decreases, while the oxygen content increases; the hydrogen, being the main component of the gas fraction and having a small atomic weight, is responsible for the progressive reduction of the gas density at higher temperature.

Clay Animals and Their Habitats

Science.gov (United States)

Adamson, Kay

2010-01-01

Creating clay animals and their habitats with second-grade students has long been one of the author's favorite classroom activities. Students love working with clay and they also enjoy drawing animal homes. In this article, the author describes how the students created a diorama instead of drawing their clay animal's habitat. This gave students…

Surface modification of montmorillonite on surface Acid-base characteristics of clay and thermal stability of epoxy/clay nanocomposites.

Science.gov (United States)

Park, Soo-Jin; Seo, Dong-Il; Lee, Jae-Rock

2002-07-01

In this work, the effect of surface treatments on smectitic clay was investigated in surface energetics and thermal behaviors of epoxy/clay nanocomposites. The pH values, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) were used to analyze the effect of cation exchange on clay surface and the exfoliation phenomenon of clay interlayer. The surface energetics of clay and thermal properties of epoxy/clay nanocomposites were investigated in contact angles and thermogravimetric analysis (TGA), respectively. From the experimental results, the surface modification of clay by dodecylammonium chloride led to the increases in both distance between silicate layers of about 8 A and surface acid values, as well as in the electron acceptor component (gamma(+)(s)) of surface free energy, resulting in improved interfacial adhesion between basic (or electron donor) epoxy resins and acidic (electron acceptor) clay interlayers. Also, the thermal stability of nanocomposites was highly superior to pure epoxy resin due to the presence of the well-dispersed clay nanolayer, which has a barrier property in a composite system.

21 CFR 186.1256 - Clay (kaolin).

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Clay (kaolin). 186.1256 Section 186.1256 Food and... Substances Affirmed as GRAS § 186.1256 Clay (kaolin). (a) Clay (kaolin) Al2O3.2SiO2.nH2O, Cas Reg. No. 1332-58-7) consists of hydrated aluminum silicate. The commercial products of clay (kaolin) contain...

Quantifying the effect of squirt flow dispersion from compliant clay porosity in clay bearing sandstones

DEFF Research Database (Denmark)

Sørensen, Morten Kanne; Fabricius, Ida Lykke

2013-01-01

Compliant porosity in the form of cracks is known to cause significant attenuation and velocity dispersion through pore pressure gradients and consequent relaxation, dubbed squirt flow. Squirt flow from cracks vanish at high confining stress due to crack closing. Studies on clay bearing sandstones......-squirt flow on the bulk modulus of a clay bearing sandstone. The predicted magnitude of the clay-squirt effect on the bulk modulus is compared with experimental data. The clay-squirt effect is found to possibly account for a significant portion of the deviances from Gassmann fluid substitution in claybearing...... sandstones....

Characterization of Heat-treated Clay Minerals in the Context of Nuclear Waste Disposal

Science.gov (United States)

Matteo, E. N.; Wang, Y.; Kruichak, J. N.; Mills, M. M.

2015-12-01

Clay minerals are likely candidates to aid in nuclear waste isolation due to their low permeability, favorable swelling properties, and high cation sorption capacities. Establishing the thermal limit for clay minerals in a nuclear waste repository is a potentially important component of repository design, as flexibility of the heat load within the repository can have a major impact on the selection of repository design. For example, the thermal limit plays a critical role in the time that waste packages would need to cool before being transferred to the repository. Understanding the chemical and physical changes, if any, that occur in clay minerals at various temperatures above the current thermal limit (of 100 °C) can enable decision-makers with information critical to evaluating the potential trade-offs of increasing the thermal limit within the repository. Most critical is gaining understanding of how varying thermal conditions in the repository will impact radionuclide sorption and transport in clay materials either as engineered barriers or as disposal media. A variety of repository-relevant clay minerals (illite, mixed layer illite/smectite, and montmorillonite), were heated for a range of temperatures between 100-1000 °C. These samples were characterized to determine surface area, mineralogical alteration, and cation exchange capacity (CEC). Our results show that for conditions up to 500 °C, no significant change occurs, so long as the clay mineral remains mineralogically intact. At temperatures above 500 °C, transformation of the layered silicates into silica phases leads to alteration that impacts important clay characteristics. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's Nation Nuclear Security Administration under contract DE-AC04-94AL85000. SAND Number: SAND2015-6524 A

Magnetic resonance imaging of clays: swelling, sedimentation, dissolution

Science.gov (United States)

Dvinskikh, Sergey; Furo, Istvan

2010-05-01

measure of clay distribution in extended samples during different physical processes such as swelling, dissolution, and sedimentation on the time scale from minutes to years [1-3]. To characterize the state of colloids that form after/during clay swelling the water self-diffusion coefficient was measured on a spatially resolved manner. Both natural clays and purified and ion-exchanged montmorillonite clays were investigated. The primary variables were clay composition and water ionic strength. These results have a significant impact for engineering barriers for storage of spent nuclear fuel where clay erosion by low salinity water must be addressed. Presented methods were developed under the motivation of using bentonite clays as a buffer medium to build in-ground barriers for the encapsulation of radioactive waste. Nevertheless, the same approaches can be found suitable in other applications in soil and environmental science to study other types of materials as they swell, dissolve, erode, or sediment. Acknowledgements: This work has been supported by the Swedish Nuclear Fuel and Waste Management Co (SKB) and the Swedish Research Council VR. [1] N. Nestle, T. Baumann, R. Niessner, Magnetic resonance imaging in environmental science. Environ. Sci. Techn. 36 154A (2002). [2] S. V. Dvinskikh, K. Szutkowski, I. Furó. MRI profiles over a very wide concentration ranges: application to swelling of a bentonite clay. J. Magn. Reson. 198 146 (2009). [3] S. V. Dvinskikh, I. Furó. Magnetic resonance imaging and nuclear magnetic resonance investigations of bentonite systems. Technical Report, TR-09-27, SKB (2009), www.skb.se.

Influence of Two Compatibilizers on Clay/PP Nanocomposites Properties

DEFF Research Database (Denmark)

Potarniche, Catalina-Gabriela; Vuluga, Zina; Christiansen, Jesper de Claville

2013-01-01

-screw extruder was used to obtain nanocomposites based on polypropylene via the melt intercalation technique. X-ray diffraction and differential scanning calorimetric results showed that intercalated nanocomposites with improved thermal stability were obtained. Increases of 8% in tensile strength, 34% in modulus......, and 20% in crystallinity were observed. Also an increase of 23% in creep properties was observed when using these two compatibilizer system and 1% clay. POLYM. ENG. SCI., 00:000–000, 2012. ª2012 Society of Plastics Engineers...

Mineral acquisition from clay by budongo forest chimpanzees

NARCIS (Netherlands)

Reynolds, Vernon; Lloyd, Andrew W.; English, Christopher J.; Lyons, Peter; Dodd, Howard; Hobaiter, Catherine; Newton-Fisher, Nicholas; Mullins, Caroline; Lamon, Noemie; Schel, Anne Marijke; Fallon, Brittany

2015-01-01

Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay

Clay Characterization as Engineered Barrier to Contaminants Migration: Thermal, Hydraulic and Mechanical Properties

International Nuclear Information System (INIS)

Bru, A.; Casero, D.

2001-01-01

In this work we characterize the structure of a clay, concretely bentonite. Our main aim is to stress the important role that plays the heterogeneity of the medium structure in transport processes. Randomness of pore sizes produces an anomalous transport of contaminants. We analyze mercuric porosimetry data with simulations finding that pore size distribution has a power-law behaviour. (Author) 6 refs

Evaluation of kaolinite clays of Moa for the production of cement based clinker-calcined clay-limestone (LC3

Directory of Open Access Journals (Sweden)

Roger S. Almenares-Reyes

2016-12-01

Full Text Available Clay materials from two outcrops of the Moa region were analyzed to determine their potential use as supplementary cementitious material in the production of ternary cements based on limestone-calcined clay. The clays were characterized by atomic absorption spectroscopy (EAA, X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR and thermogravimetric analysis (ATG. These methods revealed high aluminum in clays, moderate kaolinite content, a disordered structure and the presence of impurities. The solubility of aluminum and silicon in alkali and the compressive strength of LC3 systems is proportional to their content in clay, being higher for the one with higher kaolinite content and greater structural disorder (outcrop D1, although the clay of both outcrops may constitute supplementary cementitious materials in the production of ternary cements based clinker-calcined clay-limestone. The suitable thermal activation range for both clays is between 650 ° C and 850 ° C.

Influence of herbicide structure, clay acidity, and humic acid coating on acetanilide herbicide adsorption on homoionic clays.

Science.gov (United States)

Liu, Weiping; Gan, Jianying; Yates, Scott R

2002-07-03

Adsorption of chloroacetanilide herbicides on homoionic montmorillonite was studied by coupling batch equilibration and FT-IR analysis. Adsorption decreased in the order metolachlor > acetochlor > alachlor > propachlor on Ca(2+)- or Mg(2+)-saturated clays and in the order metolachlor > alachlor > acetachlor > propachlor on Al(3+)- or Fe(3+)-saturated clays. FT-IR spectra showed that the carbonyl group of the herbicide molecule was involved in bonding. For the same herbicide, adsorption of alachlor, acetachlor, and metolachlor on clay followed the order Ca(2+) approximately Mg(2+) < Al(3+) < or = Fe(3+), which coincided with the increasing acidity of homoionic clays. Adsorption of propachlor, however, showed an opposite dependence, suggesting a different governing interaction. In clay and humic acid mixtures, herbicide adsorption was less than that expected from independent additive adsorption by the individual constituents, and the deviation was dependent on the clay-to-humic acid ratio, with the greatest deviation consistently occurring at a 60:40 clay-to-humic acid ratio.

Cooking time harmonization attempts for main rubbers in a truck tyre-III. Activation energy evaluation

International Nuclear Information System (INIS)

Kadima, T.H.

2011-01-01

The harmonization of optimum cooking time of rubbers containing in a tyre is became possible. This occurrence is the result of the knowledge about the respective function of each element containing in the rubber. Many kind of rubbers are been studied. The obtained results demonstrate the realization of the harmonization of optimum cooking time in different rubbers at some conditions by modifying either a kind of vulcanization accelerator or a quantity of vulcanization activator. So, accelerator or activator modifies need of energy during cooking. In this paper, we are estimated activation energy for all new rubbers obtained

Characterization of Burnt Clays by X-ray Diffraction Analysis, Chemical Analysis and Environmental Scanning Electron Microscopy

Czech Academy of Sciences Publication Activity Database

Navrátilová, Eva; Neděla, Vilém

2016-01-01

Roč. 22, S3 (2016), s. 1862-1863 ISSN 1431-9276 Institutional support: RVO:68081731 Keywords : burnt clays * pozzolanic activity * amorphous phase * environmental scanning electron microscope Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.891, year: 2016

Pre-treatment of waste fuel with low-speed shredding and screening for fluidized bed incineration; Foerbehandling av avfallsbraensle foer fluidbaeddpannor med laangsamtgaaende valskross och saekerhetssiktning

Energy Technology Data Exchange (ETDEWEB)

Hermansson, Sven; Victoren, Anders; Niklasson, Fredrik; Jones, Frida

2013-09-01

In FB combustion of waste, an important cost factor is the pre-treatment of the waste fuel. The most common method of final levigation of the waste fuel is using hammer mills, which crushes the fuel with high force and high rotational speed. The advantage of the powerful hammer mill is, however, also a disadvantage. The fraction of fines becomes large, and the method is experienced to cause high maintenance costs and problems with accidental fires. A plausible alternative to the hammer mill is the shredder. The rotational speed of the shreeder is lower, while it cutting and slicing the waste fuel instead of grinding it. The shredder is, therefore, expected to yield less wear and tear, lower electricity consumption and less accidental fires. On the other hand, the shreeder may yield a higher fraction of oversized fuel particles, which could cause problems in the combustion, especially in smaller FB-plants with one single fuel supply conveyor. In this project, the framing of question has been if low-speed shredding in combination with screening of over sizes fuel particles, may function for smaller FB plants with one single fuel supplying conveyor. The aim of the project has been to support FB plant owners and manufacturers for independent comparision of the different fuel pre-treatment methods, via pre-treatment and combustions trials and economical comparisons. The concept of lowspeed shreddning and screening has been compared economically with a traditional hammer mill system and a shredding system designed for a larger FB plant. Moreover, combustion trials have been carried out with shredded and screened fuel, and hammer milled fuel, in two smaller parallel FB furnaces with one single fuel supplying conveyor per furnace. The fuels were analysed for particle size distribution and composition, and the operation during the combustion trial was evaluated. The economical evaluation of the new pre-treatment concept, with lowspeed shredding and screening, yielded an

Atom exchange between aqueous Fe(II) and structural Fe in clay minerals.

Science.gov (United States)

Neumann, Anke; Wu, Lingling; Li, Weiqiang; Beard, Brian L; Johnson, Clark M; Rosso, Kevin M; Frierdich, Andrew J; Scherer, Michelle M

2015-03-03

Due to their stability toward reductive dissolution, Fe-bearing clay minerals are viewed as a renewable source of Fe redox activity in diverse environments. Recent findings of interfacial electron transfer between aqueous Fe(II) and structural Fe in clay minerals and electron conduction in octahedral sheets of nontronite, however, raise the question whether Fe interaction with clay minerals is more dynamic than previously thought. Here, we use an enriched isotope tracer approach to simultaneously trace Fe atom movement from the aqueous phase to the solid ((57)Fe) and from the solid into the aqueous phase ((56)Fe). Over 6 months, we observed a significant decrease in aqueous (57)Fe isotope fraction, with a fast initial decrease which slowed after 3 days and stabilized after about 50 days. For the aqueous (56)Fe isotope fraction, we observed a similar but opposite trend, indicating that Fe atom movement had occurred in both directions: from the aqueous phase into the solid and from the solid into aqueous phase. We calculated that 5-20% of structural Fe in clay minerals NAu-1, NAu-2, and SWa-1 exchanged with aqueous Fe(II), which significantly exceeds the Fe atom layer exposed directly to solution. Calculations based on electron-hopping rates in nontronite suggest that the bulk conduction mechanism previously demonstrated for hematite1 and suggested as an explanation for the significant Fe atom exchange observed in goethite2 may be a plausible mechanism for Fe atom exchange in Fe-bearing clay minerals. Our finding of 5-20% Fe atom exchange in clay minerals indicates that we need to rethink how Fe mobility affects the macroscopic properties of Fe-bearing phyllosilicates and its role in Fe biogeochemical cycling, as well as its use in a variety of engineered applications, such as landfill liners and nuclear repositories.

Clay shale as host rock. A geomechanical contribution about Opalinus clay

International Nuclear Information System (INIS)

Lempp, Christof; Menezes, Flora; Sachwitz, Simon

2016-01-01

The Opalinuston is a prominent rock representing the type of organic clay shales or clay stones within the sequence of Triassic and Jurassic marine sediments in Southern Germany. The rock forms a homogenous unit some ten meters thick. The degree of consolidation of this type of pelitic rock depends mainly on the former load conditions, but is also dependent on the long-term weathering and even on the present exposition. The geomechanical parameters such as shear strength, tensional strength and permeability vary with the state of consolidation and become important when the use is discussed of such rocks for radioactive waste disposal. A tunneling project at the northern escarpment of the Swabian Alb (Southwest Germany) within the Opalinus clay offered the rare opportunity to obtain fresh unweathered rock samples in greater amounts compared to fresh drilling cores from which geomechanical investigations are usually undertaken. Consequently, the results of geomechanical laboratory testings are presented in order to compare here the results of multistep triaxial compression tests, of hydraulic fracturing laboratory tests and of some other tests for rock characterization with the corresponding results of Opalinus clay sites in Switzerland that were investigated by the Swiss Nagra Company for host rock characterization. After a discussion of the relevant state of fresh Opalinus clay, especially of suction pressure conditions and saturation state, the results of triaxial shear tests are presented. Increasing shear deformation at increasing pressure and unchanged water saturation do not result in a significant strength reduction of the Opalinus clay. The rock shows increasing cohesion and stiffness, if multiple loading has repeatedly reached the failure point. Thus there is no increased permeability with continued shearing. Only at the beginning of the shearing process is a temporarily increased permeability to be expected due to dilatation processes. An increased

Three dimensional contact stresses under the LINTRACK wide base single tyres, measured with the Vehicle-Road Surface Pressure Transducer Array (VRSPTA) system in South Africa

CSIR Research Space (South Africa)

De Beer, Morris

1996-11-01

Full Text Available testing. The vertical, transverse (or lateral) and longitudinal contact stresses between the tyres and the pavement were measured with the Vehicle-Road Surface Pressure Transducer Array (VRSPTA), developed in South Africa as part of the ongoing Accelerated...

Strength Improvement of Clay Soil by Using Stone Powder

Directory of Open Access Journals (Sweden)

Ahmed Sameer Abdulrasool

2015-05-01

Full Text Available Soil stabilization with stone powder is a good solution for the construction of subgrade for road way and railway lines, especially under the platforms and mostly in transition zones between embankments and rigid structures, where the mechanical properties of supporting soils are very influential. Stone powder often has a unique composition which justifies the need for research to study the feasibility of using this stone powder type for ground improvement applications. This paper presents results from a comprehensive laboratory study carried out to investigate the feasibility of using stone powder for improvement of engineering properties of clays. The stone powder contains bassanite (CaSO4. ½ H2O, and Calcite (CaCO3. Three percentages are used for stone powder (1%, 3% and 5% by dry weight of clay. Several tests are made to investigate the soil behavior after adding the stone powder (Atterberg limits, Standard Proctor density, Grain size distribution, Specific gravity, Unconfined Compressive test, and California bearing ratio test. Unconfined Compressive tests conducted at different curing. The samples are tested under both soaked and unsoaked condition. Chemical tests and X-ray diffraction analyses are also carried out. Stone powder reacts with clay producing decreasing in plasticity and The curves of grain size distribution are shifted to the coarse side as the stone powder percentage increase; the soil becomes more granular, and also with higher strength.

Xenon-129 NMR study of the microporous structure of clays and pillared clays

International Nuclear Information System (INIS)

Tsiao, C.; Carrado, K.A.

1990-01-01

129 Xe NMR studies have been carried out using xenon gas adsorbed in clays and pillared clays. Data from the measurements provide information on the pore structure of clays before and after pillaring. The results indicate that the effective pore diameter of montmorillonite increases, for example, from 5.4 Angstrom to 8.0 Angstrom after pillaring cheto-montmorillonite with aluminum polyoxohydroxy Keggin cations. The data are consistent with X-ray powder diffraction results, which show a corresponding increase in the interlamellar gallery height from 5.6 Angstrom to 8.4 Angstrom

Effect of Water on Elastic and Creep Properties of Self-Standing Clay Films.

Science.gov (United States)

Carrier, Benoit; Vandamme, Matthieu; Pellenq, Roland J-M; Bornert, Michel; Ferrage, Eric; Hubert, Fabien; Van Damme, Henri

2016-02-09

We characterized experimentally the elastic and creep properties of thin self-standing clay films, and how their mechanical properties evolved with relative humidity and water content. The films were made of clay montmorillonite SWy-2, obtained by evaporation of a clay suspension. Three types of films were manufactured, which differed by their interlayer cation: sodium, calcium, or a mixture of sodium with calcium. The orientational order of the films was characterized by X-ray diffractometry. The films were mechanically solicited in tension, the resulting strains being measured by digital image correlation. We measured the Young's modulus and the creep over a variety of relative humidities, on a full cycle of adsorption-desorption for what concerns the Young's modulus. Increasing relative humidity made the films less stiff and made them creep more. Both the elastic and creep properties depended significantly on the interlayer cation. For the Young's modulus, this dependence must originate from a scale greater than the scale of the clay layer. Also, hysteresis disappeared when plotting the Young's modulus versus water content instead of relative humidity. Independent of interlayer cation and of relative humidity greater than 60%, after a transient period, the creep of the films was always a logarithmic function of time. The experimental data gathered on these mesoscale systems can be of value for modelers who aim at predicting the mechanical behavior of clay-based materials (e.g., shales) at the engineering macroscopic scale from the one at the atomistic scale, for them to validate the first steps of their upscaling scheme. They provide also valuable reference data for bioinspired clay-based hybrid materials.

Investigation of the overconsolidation and structural behavior of Shanghai clays by element testing and constitutive modeling

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Guan-lin Ye

2016-09-01

Full Text Available The mechanical properties and constitutive modeling of Shanghai clays are very important for numerical analysis on geotechnical engineering in Shanghai, where continuous layers of soft clays run 30–40 m deep. The clays are divided into 5 major layers. A series of laboratory tests are carried out to investigate their mechanical properties. The top and bottom layers are overconsolidated hard clays, and the middle layers are normally consolidated or lightly overconsolidated sensitive marine clays. A constitutive model, which can describe the overconsolidation and structure of soils using only 8 parameters, is modified to simulate the test results. A rational procedure to determine the values of the material parameters and initial conditions is also proposed. The model is able to effectively reproduce both one-dimensional (1D consolidation and drained/undrained triaxial test results of Shanghai clays, with one set of parameters for each layer. From element testing and constitutive modeling, two findings are obtained. First, the decay rates of overconsolidation are smaller in overconsolidated layers than in normally consolidated layers. Second, the natural microstructure of layer 4 is relatively stable, that is, a large degree of structure is still maintained in the specimen even after 1D consolidation and drained triaxial tests. The modified model and obtained parameter values can be used for numerical analysis of geotechnical projects in Shanghai.

Status of LANL investigations of temperature constraints on clay in repository environments

International Nuclear Information System (INIS)

Caporuscio, Florie A.; Cheshire, Michael C.; Newell, Dennis L.; McCarney, Mary Kate

2012-01-01

The Used Fuel Disposition (UFD) Campaign is presently evaluating various generic options for disposal of used fuel. The focus of this experimental work is to characterize and bound Engineered Barrier Systems (EBS) conditions in high heat load repositories. The UFD now has the ability to evaluate multiple EBS materials, waste containers, and rock types at higher heat loads and pressures (including deep boreholes). The geologic conditions now available to the U.S.A. and the international community for repositories include saturated and reduced water conditions, along with higher pressure and temperature (P, T) regimes. Chemical and structural changes to the clays, in either backfill/buffer or clay-rich host rock, may have significant effects on repository evolution. Reduction of smectite expansion capacity and rehydration potential due to heating could affect the isolation provided by EBS. Processes such as cementation by silica precipitation and authigenic illite could change the hydraulic and mechanical properties of clay-rich materials. Experimental studies of these repository conditions at high P,T have not been performed in the U.S. for decades and little has been done by the international community at high P,T. The experiments to be performed by LANL will focus on the importance of repository chemical and mineralogical conditions at elevated P,T conditions. This will provide input to the assessment of scientific basis for elevating the temperature limits in clay barriers.

Innovative Mesoporous Nanosilicas: SBR Nanocomposite for Low Environmental Impact Tread Tyre.

Science.gov (United States)

Castellano, Maila; Turturro, Antonio; Finocchio, Elisabetta; Busca, Guido; Legami, Rossella Di; Vicini, Silvia

2018-02-01

Silica nanoparticles with different aspect ratios (A.R.) were tested as reinforcing fillers of styrenebutadiene copolymer (s-SBR) for "green tyres," i.e., tires with lower rolling resistance. A commercial nanosilica with A.R. = 1 (Aerosil® 200) was compared with two nanosilica samples with A.R. = 2 and 4, synthesized by means of an innovative process, to ascertain if the filler shape was significant to improve the composite properties. In addition, bis-triethoxysilylpropyltetrasulfide was grafted onto the particles surface, in order to obtain more hydrophobic materials and to enhance their dispersion in the elastomeric composites: pristine and modified silicas were then compared. Grafting extent was evaluated by thermogravimetric analysis. The surface properties of silicas were investigated by Fourier transform infrared spectroscopy and inverse gas chromatography. s-SBR/silica nanocomposites were then prepared and characterized assessing their dynamic-mechanical properties and carrying out morphological observations by transmission electron microscopy.

The effect of organic matter in clay sealing materials on the performance of a nuclear fuel waste disposal vault

International Nuclear Information System (INIS)

Oscarson, D.W.; Stroes-Gascoyne, S.; Cheung, S.C.H.

1986-12-01

The potential effect of organic matter in clay sealing materials on the performance of a nuclear fuel waste disposal vault was examined. The available data indicate that the engineering properties of clays are not significantly affected by the relatively low levels of organic matter (< 1.2 wt.%) present in the clay sealing materials. Complexing of radionuclides by organic substances that are released from the clay sealing materials or produced by microorganisms will likely inhibit rather than promote radionuclide mobility in the compacted sealing materials because of the relatively large size of organic complexing species. Decreasing the level of organic matter in the clay sealing materials will not eliminate microorganisms, and perhaps not decrease their numbers significantly, because chemolithotrophic microorganisms (microorganisms that utilize inorganic forms of C) will be present in a disposal vault. Furthermore, an examination of the nutrient budget in a disposal vault indicates that N, rather than C, will likely be the limiting nutrient for microbial growth. Finally, there is not suitable, proven method for decreasing the level of organic matter in the large amounts of clay needed to seal a vault. It is concluded that the organic matter present in the clay sealing material will not adversely affect the performance of a disposal vault

Wave liquefaction in soils with clay content

DEFF Research Database (Denmark)

Kirca, Özgür; Sumer, B. Mutlu; Fredsøe, Jørgen

2012-01-01

The paper presents the results of an experimental study of the influence of clay content (in silt-clay and sand-clay mixtures) on liquefaction beneath progressive waves. The experiments showed that the influence of clay content is very significant. Susceptibility of silt to liquefaction is increa...

Characterization of clay minerals

International Nuclear Information System (INIS)

Diaz N, C.; Olguin, M.T.; Solache R, M.; Alarcon H, T.; Aguilar E, A.

2002-01-01

The natural clays are the more abundant minerals on the crust. They are used for making diverse industrial products. Due to the adsorption and ion exchange properties of these, a great interest for developing research directed toward the use of natural clays for the waste water treatment has been aroused. As part of such researches it is very important to carry out previously the characterization of the interest materials. In this work the results of the mineral and elemental chemical composition are presented as well as the morphological characteristics of clay minerals from different regions of the Mexican Republic. (Author)

Integrated programme of research into the behaviour of the clay engineered barrier: an example from Nagra's Grimsel test site

International Nuclear Information System (INIS)

Biggin, C.; Alexander, R.; Kickmaier, W.; McKinley, I.G.

2003-01-01

Many designs for the disposal of higher activity radioactive wastes include bentonite clay as part of the engineered barrier system (EBS). Generally, the EBS is characterised by the use of large quantities of rather simple, well-understood materials, leading to increased confidence in the predicted long-term behaviour of the EBS (see, for example, Alexander and McKinley, 1999). Despite this, several open questions remain and some of these are being examined at Nagra's Grimsel Test Site (GTS) in the central Swiss Alps as part of an integrated, international study programme (GTS Phase V: see www.grimsel.com for details). Three specific projects within GTS Phase V are currently investigating the performance assessment (PA) implications of the behaviour of bentonite in the EBS. In the first, demonstration of the overall practicability of the Spanish reference disposal concept (where canisters are placed horizontally in bentonite backfilled tunnels) for high level waste (HLW) is amongst the goals of ENRESA's Full-scale Engineered Barrier EXperiment (FEBEX). In the second, RWMC are examining the potential effects of gas migration through a bentonite-sand mixture surrounding a concrete silo in the Japanese concept for intermediate level waste (ILW) in a large-scale EBS experiment (GMT, Gas Migration Test). Finally, Nagra, in the CRR (Colloid and Radionuclide Retardation) project, is investigating the effects of bentonite colloids on migration of radionuclides at the EBS / geosphere boundary, where bentonite colloids could be produced by erosion of the bentonite backfill. Although all three projects have produced significant advances in the understanding of the behaviour of the clay EBS under in situ conditions, they are based on first generation conceptual designs and so, in the planned Phase VI of the GTS, it is proposed to move on and consider more optimised EBS designs and emplacement techniques. To facilitate integration, the focus of Phase VI will be narrowed to

Clays and Clay Minerals and their environmental application in Food Technology

Science.gov (United States)

del Hoyo Martínez, Carmen; Cuéllar Antequera, Jorge; Sánchez Escribano, Vicente; Solange Lozano García, Marina; Cutillas Díez, Raul

2013-04-01

The clay materials have led to numerous applications in the field of public health (del Hoyo, 2007; Volzone, 2007) having been demonstrated its effectiveness as adsorbents of all contaminants. Some biodegradable materials are used for for adsorption of chemical contaminants: lignins (Valderrabano et al., 2008) and also clays and clay minerals, whose colloidal properties, ease of generating structural changes, abundance in nature, and low cost make them very suitable for this kind of applications. Among the strategies used at present to preserve the quality of the water and this way to diminish the environmental risk that supposes the chemical pollution, stands out the use of adsorbents of under cost, already they are natural or modified, to immobilize these compounds and to avoid the pollution of the water with the consequent reduction of environmental and economic costs Thanks to the development of the science and the technology of the nourishment in the last 50 years, there have revealed itself several new substances that can fulfill beneficial functions in the food, and these substances, named food additives, are today within reach of all. The food additives recover a very important role in the complex nourishing supply. The additives fulfill several useful functions in the food, which often we give for sat. Nevertheless the widespread use of food additives in the food production also influences the public health. The food industries, which are very important for the economy, spill residues proved from its activity that they have to be controlled to evaluate the environmental impact and to offer the necessary information about the quantitative evaluation of the chemical risk of the use of food additives for the public health. We have studied the adsorption of several contaminants by natural or modified clays, searching their interaction mechanisms and the possible recycling of these materials for environmental purposes and prevention of the health. References

Mineral Acquisition from Clay by Budongo Forest Chimpanzees.

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Vernon Reynolds

Full Text Available Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consumed indicates that it takes the form of kaolinite. We discuss the contribution of clay geophagy to the mineral intake of the Sonso chimpanzees and show that clay eaten using leaf sponges is particularly rich in minerals. We show that termite mound soil, also regularly consumed, is rich in minerals. We discuss the frequency of clay and termite soil geophagy in the context of the disappearance from Budongo Forest of a formerly rich source of minerals, the decaying pith of Raphia farinifera palms.

Mineral Acquisition from Clay by Budongo Forest Chimpanzees.

Science.gov (United States)

Reynolds, Vernon; Lloyd, Andrew W; English, Christopher J; Lyons, Peter; Dodd, Howard; Hobaiter, Catherine; Newton-Fisher, Nicholas; Mullins, Caroline; Lamon, Noemie; Schel, Anne Marijke; Fallon, Brittany

2015-01-01

Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consumed indicates that it takes the form of kaolinite. We discuss the contribution of clay geophagy to the mineral intake of the Sonso chimpanzees and show that clay eaten using leaf sponges is particularly rich in minerals. We show that termite mound soil, also regularly consumed, is rich in minerals. We discuss the frequency of clay and termite soil geophagy in the context of the disappearance from Budongo Forest of a formerly rich source of minerals, the decaying pith of Raphia farinifera palms.

Influence of carbonate micro-fabrics on the failure strength of Callovo-Oxfordian clay stones and Opalinus Clay

International Nuclear Information System (INIS)

Klinkenberg, M.; Dohrmann, R.; Kaufhold, S.; Siegesmund, S.

2010-01-01

Document available in extended abstract form only. The potential use of clay stones as host rock for radioactive waste disposal is currently investigated. For this application, hydraulic conductivity, swelling properties, water uptake, rheological and mechanical properties are of great importance. The Opalinus Clay (Mont-Terri, Switzerland) and the Callovo- Oxfordian clay stone (France) are the most frequently studied clay stones. One goal is to develop a numerical model being able to predict the mechanical behaviour of clay stones under repository-like conditions. Experimental investigations reveal that Opalinus Clay and Callovo-Oxfordian clay stone behave different with respect to the dependence of mechanical strength on the carbonate content. The failure strength of Opalinus Clay decreases with increasing carbonate content, whereas it increases with increasing carbonate content when Callovo-Oxfordian clay stone is considered. To supply proper data and enable reliable model assumptions, the use of suitable experimental techniques for the description of the microstructure is indispensable. After mechanical testing, samples were taken perpendicular to the bedding and polished sections were prepared. The micro-fabrics were investigated using scanning electron microscopy (SEM) and image analysis. Backscattered electron (BSE) images were used for the image analysis because carbonates can be extracted by grey level analysis. The image analysis of the extracted particles provides the following parameters: area, longest and shortest axis of an ellipse (surrounding the particle), perimeter, the angle to horizontal (longest axis), and the aspect ratio (longest axis/shortest axis). Callovo-Oxfordian clay stone shows a homogenous distribution of fine-grained carbonates and dovetail connection of calcium carbonate with the clayey matrix. In contrast Opalinus Clay shows large elongated carbonate grains (high aspect ratios) of shell fragments. Cracks are mostly related to these

Properties and applications of polymer nanocomposites clay and carbon based polymer nanocomposites

CERN Document Server

Prasad Sahoo, Bibhu

2017-01-01

The aim of the present edited book is to furnish scientific information about manufacturing, properties, and application of clay and carbon based polymer nanocomposites. It can be used as handbook for undergraduate and post graduate courses (for example material science and engineering, polymer science and engineering, rubber technology, manufacturing engineering, etc.) as well as as reference book for research fellows and professionals. Polymer nanocomposites have received outstanding importance in the present decade because of their broad range of high-performance applications in various areas of engineering and technology due to their special material properties. A great interest is dedicated to nanofiller based polymeric materials, which exhibit excellent enhancement in macroscopic material properties (mechanical, thermal, dynamic mechanical, electrical and many more) at very low filler contents and can therefore be used for the development of next-generation composite materials.

Preparation of nanocomposites polyurethane water bone with clay montmorillonite sodica and organophilic clay

International Nuclear Information System (INIS)

Garcia, Claudia P.; Delpech, Marcia C.; Coutinho, Fernanda M.B.; Mello, Ivana L.

2009-01-01

Nanocomposites based on water bone polyurethane (NWPU's) were synthesized based on poli(propylene glycol), dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI) and hydrazine (HYD), as chain extender. Two kinds of clays were employed: hydrophilic and organophilic. The nanocomposites were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electronic microscopy (SEM) and the mechanical properties were evaluated. The FTIR results showed the presence of specific groups of clay and the XRD suggested that occurred their intercalation/exfoliation through polyurethane matrix. The mechanical resistance of the systems showed significant increase when compared to water dispersions synthesized without clay. (author)

CHARACTERIZATION OF BENTONITE FOR ENGINEERED BARRIER SYSTEMS IN RADIOACTIVE WASTE DISPOSAL SITES

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Dubravko Domitrović

2012-07-01

Full Text Available Engineered barrier systems are used in radioactive waste disposal sites in order to provide better protection of humans and the environment from the potential hazards associated with the radioactive waste disposal. The engineered barrier systems usually contain cement or clay (bentonite because of their isolation properties and long term performance. Quality control tests of clays are the same for all engineering barrier systems. Differences may arise in the required criteria to be met due for different application. Prescribed clay properties depend also on the type of host rocks. This article presents radioactive waste management based on best international practice. Standard quality control procedures for bentonite used as a sealing barrier in radioactive waste disposal sites are described as some personal experiences and results of the index tests (free swelling index, water adsorption capacity, plasticity limits and hydraulic permeability of bentonite (the paper is published in Croatian.

Crude oil polycyclic aromatic hydrocarbons removal via clay-microbe-oil interactions: Effect of acid activated clay minerals.

Science.gov (United States)

Ugochukwu, Uzochukwu C; Fialips, Claire I

2017-07-01

Acid treatment of clay minerals is known to modify their properties such as increase their surface area and surface acidity, making them suitable as catalysts in many chemical processes. However, the role of these surface properties during biodegradation processes of polycyclic aromatic hydrocarbons (PAHs) is only known for mild acid (0.5 M Hydrochloric acid) treated clays. Four different clay minerals were used for this study: a montmorillonite, a saponite, a palygorskite and a kaolinite. They were treated with 3 M hydrochloric acid to produce acid activated clay minerals. The role of the acid activated montmorillonite, saponite, palygorskite and kaolinite in comparison with the unmodified clay minerals in the removal of PAHs during biodegradation was investigated in microcosm experiments. The microcosm experiments contained micro-organisms, oil, and clays in aqueous medium with a hydrocarbon degrading microorganism community predominantly composed of Alcanivorax spp. Obtained results indicated that acid activated clays and unmodified kaolinite did not enhance the biodegradation of the PAHs whereas unmodified montmorillonite, palygorskite and saponite enhanced their biodegradation. In addition, unmodified palygorskite adsorbed the PAHs significantly due to its unique channel structure. Copyright © 2017 Elsevier Ltd. All rights reserved.

From clay bricks to deep underground storage

International Nuclear Information System (INIS)

2012-05-01

This booklet issued by the Swiss National Cooperative for the Disposal of Radioactive Waste NAGRA takes a look at the use of clay strata for the storage of radioactive wastes in deep-lying repositories. First of all, a geological foray is made concerning the history of the use of clay and its multifarious uses. The characteristics of clay and its composition are examined and its formation in the geological past is explained. In particular Opalinus clay is looked at and the structures to be found are discussed. The clay's various properties and industrial uses are examined and its sealing properties are examined. Also, Bentonite clay is mentioned and work done by Nagra and co-researchers is noted

Microstructure and Thermal Properties of Polypropylene/Clay Nanocomposites with TiCl4/MgCl2/Clay Compound Catalyst

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Limei Wang

2015-01-01

Full Text Available Polypropylene (PP/clay nanocomposites were synthesized by in situ intercalative polymerization with TiCl4/MgCl2/clay compound catalyst. Microstructure and thermal properties of PP/clay nanocomposites were studied in detail. Fourier transform infrared (FTIR spectra indicated that PP/clay nanocomposites were successfully prepared. Both wide-angle X-ray diffraction (XRD and transmission electron microscopy (TEM examination proved that clay layers are homogeneously distributed in PP matrix. XRD patterns also showed that the α phase was the dominate crystal phase of PP in the nanocomposites. Thermogravimetric analysis (TGA examinations confirmed that thermal stability of PP/clay nanocomposites was markedly superior to pure PP. Differential scanning calorimetry (DSC scans showed that the melt temperature and the crystallinity of nanocomposites were slightly lower than those of pure PP due to crystals imperfections.

Iodide Sorption to Clays and the Relationship to Surface Charge and Clay Texture - 12356

Energy Technology Data Exchange (ETDEWEB)

Miller, Andrew; Kruichiak, Jessica; Tellez, Hernesto; Wang, Yifeng [Sandia National Laboratories, Albuquerque, NM 87185 (United States)

2012-07-01

Iodine is assumed to behave conservatively in clay barriers around nuclear waste repositories and in natural sediments. Batch experiments tend to show little to no sorption, while in column experiments iodine is often retarded relative to tritiated water. Current surface complexation theory cannot account for negatively charged ion sorption to a negatively charged clay particle. Surface protonation and iodide sorption to clay minerals were examined using surface titrations and batch sorption experiments with a suite of clay minerals. Surface titrations were completed spanning a range of both pH values and ionic strengths. For reference, similar titrations were performed on pure forms of an Al-O powder. The titration curves were deconvoluted to attain the pKa distribution for each material at each ionic strength. The pKa distribution for the Al-O shows two distinct peaks at 4.8 and 7.5, which are invariant with ionic strength. The pKa distribution of clays was highly variable between the different minerals and as a function of ionic strength. Iodide sorption experiments were completed at high solid:solution ratios to exacerbate sorption properties. Palygorskite and kaolinite had the highest amount of iodide sorption and montmorillonite had the least. (authors)

Feasibility of using overburden clays for sealing purposes and laboratory testing of the clays

Energy Technology Data Exchange (ETDEWEB)

Mann, J. (Vyzkumny Ustav pro Hnede Uhli, Most (Czechoslovakia))

1992-03-01

Studies properties of overburden clay from North Bohemian surface coal mines for use as sealants of industrial and household waste that will be dumped at Czechoslovak surface mine sites. Basic requirements of sealing layers are optimum compressibility and impermeability by suitable compacting. Laboratory soil mechanical tests of different clay samples were carried out using the Proctor standard tests (PCS) and the Norwegian Geonor A/S - m 45 instrument. Laboratory tests were used to select the best available clay types with optimum density and moisture content. Experimental results of laboratory tests are provided.

Efficient direct yaw moment control: tyre slip power loss minimisation for four-independent wheel drive vehicle

Science.gov (United States)

Kobayashi, Takao; Katsuyama, Etsuo; Sugiura, Hideki; Ono, Eiichi; Yamamoto, Masaki

2018-05-01

This paper proposes an efficient direct yaw moment control (DYC) capable of minimising tyre slip power loss on contact patches for a four-independent wheel drive vehicle. Simulations identified a significant power loss reduction with a direct yaw moment due to a change in steer characteristics during acceleration or deceleration while turning. Simultaneously, the vehicle motion can be stabilised. As a result, the proposed control method can ensure compatibility between vehicle dynamics performance and energy efficiency. This paper also describes the results of a full-vehicle simulation that was conducted to examine the effectiveness of the proposed DYC.

Sorption of radionuclides by tertiary clays

International Nuclear Information System (INIS)

Wagner, J.F.; Czurda, K.A.

1990-01-01

The sorption capacity of different clay types for some metals (Co, Cs, Sr and Zn), occurring as common radionuclides in radioactive waste deposits, had been analysed by a static (batch technique) and a dynamic method (percolation tests, in which the driving force is a hydraulic gradient). Sorption capacity generally increased with an increasing pH of solution. A decrease of sorption capacity had been observed in the order Zn > Cs ≥ Co > Sr for the batch and Cs > Zn > Sr > Co for the percolation tests. Clay marls showed a distinctly higher sorption respectively retention capacity as pure clays. Sorption capacity depends on solution parameters like type and concentration of radionuclide, pH, salt concentration, etc., and on rock parameters like mineral content (e.g. swelling clay minerals and carbonates), organic material, rock pH, micro fabric, etc. A third parameter of great influence is the contact time between clay and solution. The adsorption isotherms reflect two different adsorption mechanisms: a very rapid adsorption (a few minutes) on the external surfaces of clay minerals and a slow adsorption process (weeks and longer), due to the diffusion of metal ions into the interlayer space of clay minerals. 12 refs., 9 figs., 1 tab

Organophilization and characterization of commercial bentonite clays

International Nuclear Information System (INIS)

Cunha, B.B. da; Lima, J.C.C.; Alves, A.M.; Araujo, E.M.; Melo, T.J.A. de

2012-01-01

Bentonite clay is a plastic changes resulting from volcanic ash, consisting mostly of montmorillonite. The state of Paraiba is a major source of bentonite clay from Brazil, where the main oil fields are located in Boa Vista and represents the largest national production of raw and beneficiated bentonite. Aimed at the commercial value of this type of clay and its high applicability in the polls, this article aims to make a comparison between two kinds of clay, a national (Brasgel) and other imported (Cloisite) from organophilization of two commercial bentonite, ionic surfactant with Praepagem WB, and characterize them by XRD, FTIR and TG / DTG. We observe that despite getting inferior properties, the clay presents national values very similar to those presented by imported clay. (author)

Thermal Behaviour of clay formations

International Nuclear Information System (INIS)

Tassoni, E.

1985-01-01

The programme carried out by ENEA to model the thermal-hydraulic-mechanical behaviour of the clay formations and to measure, in situ and in laboratory, the thermal properties of these rocks, is presented. An in situ heating experiment has been carried out in an open clay quarry in the area of Monterotondo, near Rome. The main goal of the experiment was to know the temperature field and the thermal effects caused by the high level radioactive waste disposed of in a clayey geological formation. The conclusions are as follows: - the thermal conduction codes are sufficiently accurate to forecast the temperature increases caused in the clay by the dissipation of the heat generated by high level radioactive waste; - the thermal conductivity deduced by means of the ''curve fitting'' method ranges from 0.015 to 0.017 W.cm -1 . 0 C -1 - the temperature variation associated with the transport of clay interstitial water caused by temperature gradient is negligible. A laboratory automated method has been designed to measure the thermal conductivity and diffusivity in clay samples. A review of experimental data concerning thermomechanical effects in rocks as well as results of thermal experiments performed at ISMES on clays are presented. Negative thermal dilation has been found both in the elastic and plastic range under constant stress. Thermoplastic deformation appears ten times greater than the thermoelastic one. A mathematical model is proposed in order to simulate the above and other effects that encompass thermal-elastic-plastic-pore water pressure response of clays at high temperature and effective pressure with undrained and transient drainage conditions. Implementation of the two versions into a finite element computer code is described

Silt-clay aggregates on Mars

International Nuclear Information System (INIS)

Greeley, R.

1979-01-01

Viking observations suggest abundant silt and clay particles on Mars. It is proposed that some of these particles agglomerate to form sand size aggregates that are redeposited as sandlike features such as drifts and dunes. Although the binding for the aggregates could include salt cementation or other mechanisms, electrostatic bonding is considered to be a primary force holding the aggregates together. Various laboratory experiments conducted since the 19th century, and as reported here for simulated Martian conditions, show that both the magnitude and sign of electrical charges on windblown particles are functions of particle velocity, shape and composition, atmospheric pressure, atmospheric composition, and other factors. Electrical charges have been measured for saltating particles in the wind tunnel and in the field, on the surfaces of sand dunes, and within dust clouds on earth. Similar, and perhaps even greater, charges are proposed to occur on Mars, which could form aggregates of silt and clay size particles. Electrification is proposed to occur within Martian dust clouds, generating silt-clay aggregates which would settle to the surface where they may be deposited in the form of sandlike structures. By analog, silt-clay dunes are known in many parts of the earth where silt-clay aggregated were transported by saltation and deposited as 'sand.' In these structures the binding forces were later destroyed, and the particles reassumed the physical properties of silt and clay, but the sandlike bedding structure within the 'dunes' was preserved. The bedding observed in drifts at the Viking landing site is suggested to result from a similar process involving silt-clay aggregates on Mars

Deformability Parameters of Varved Clays From the Iłów (Central Poland Area Based on the Selected Field Tests

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Zawrzykraj Piotr Zbigniew

2017-03-01

Full Text Available This publication presents the results of research carried out for the ice-dammed clays of the Iłów region, formed during Vistula glaciation. Pressuremeter tests, dilatometer tests and static probes were made. The tests were performed on the study site in Piskorzec near Iłów. In this region, ice-dammed clays are present almost from the land surface reaching the thickness of about 11 m. This site is the westernmost experimental site of clays of the “Warsaw Ice-Dammed Lake” among those presented in the literature. Research and their analysis showed differences in deformability due to the test procedure in connection with the structure of varved clays. Pressuremeter test, even though it is the most time consuming and challenging among the tests performed, allows the most complete characteristics of deformability of varved clays to be obtained. Vertical profile of clays being studied appears to be fairly homogeneous in terms of mechanical properties. Nevertheless, some parts of the profile clearly differ from the average values. This indicates the rate of post sedimentary changes varied in different parts of research profile. The data obtained are consistent with the values for ice-dammed clays from Radzymin and Sochaczew areas. Comparison of the engineering properties of varved clays to other experimental sites points to their similar geological history. It confirms that the experimental sites belong to one ice-dammed lake covering the areas of the Warsaw Basin.

What Makes a Natural Clay Antibacterial?

Science.gov (United States)

Williams, Lynda B.; Metge, David W.; Eberl, Dennis D.; Harvey, Ronald W.; Turner, Amanda G.; Prapaipong, Panjai; Poret-Peterson, Amisha T.

2011-01-01

Natural clays have been used in ancient and modern medicine, but the mechanism(s) that make certain clays lethal against bacterial pathogens has not been identified. We have compared the depositional environments, mineralogies, and chemistries of clays that exhibit antibacterial effects on a broad spectrum of human pathogens including antibiotic resistant strains. Natural antibacterial clays contain nanoscale (clay minerals in the bactericidal process is to buffer the aqueous pH and oxidation state to conditions that promote Fe2+ solubility. Chemical analyses of E. coli killed by aqueous leachates of an antibacterial clay show that intracellular concentrations of Fe and P are elevated relative to controls. Phosphorus uptake by the cells supports a regulatory role of polyphosphate or phospholipids in controlling Fe2+. Fenton reaction products can degrade critical cell components, but we deduce that extracellular processes do not cause cell death. Rather, Fe2+ overwhelms outer membrane regulatory proteins and is oxidized when it enters the cell, precipitating Fe3+ and producing lethal hydroxyl radicals. PMID:21413758

Electric Resistance Tests on Compacted Clay Material under Dynamic Load Coupled with Dry-Wet Cycling

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Zheng Lu

2018-01-01

Full Text Available The study of compacted clay material under dynamic load coupled with dry-wet cycling is one of the most important areas in the field of transportation. In this paper, experiments in terms of compacted clay under dynamic load coupled with dry-wet cycling are performed, and synchronous resistivity tests are also conducted. According to the test results, the influences of cumulative plastic strain, dry-wet cycles, and amplitudes on the soil resistivity are analyzed. Then a new damage factor based on resistivity is proposed to evaluate the long-term performance of compacted clay material. The result of research shows that the evolution of the soil resistivity can be divided into two stages, which has a contrary tendency with that of cumulative plastic strain. The dry-wet cycles and amplitudes have a significant effect on the damage of the compacted soil, which indicates that the dry-wet cycling of compacted soil materials should not be ignored in road engineering, especially in rainy and humid areas.

Iodide uptake by negatively charged clay interlayers?

International Nuclear Information System (INIS)

Miller, Andrew; Kruichak, Jessica; Mills, Melissa; Wang, Yifeng

2015-01-01

Understanding iodide interactions with clay minerals is critical to quantifying risk associated with nuclear waste disposal. Current thought assumes that iodide does not interact directly with clay minerals due to electrical repulsion between the iodide and the negatively charged clay layers. However, a growing body of work indicates a weak interaction between iodide and clays. The goal of this contribution is to report a conceptual model for iodide interaction with clays by considering clay mineral structures and emergent behaviors of chemical species in confined spaces. To approach the problem, a suite of clay minerals was used with varying degrees of isomorphic substitution, chemical composition, and mineral structure. Iodide uptake experiments were completed with each of these minerals in a range of swamping electrolyte identities (NaCl, NaBr, KCl) and concentrations. Iodide uptake behaviors form distinct trends with cation exchange capacity and mineral structure. These trends change substantially with electrolyte composition and concentration, but do not appear to be affected by solution pH. The experimental results suggest that iodide may directly interact with clays by forming ion-pairs (e.g., NaI (aq) ) which may concentrate within the interlayer space as well as the thin areas surrounding the clay particle where water behavior is more structured relative to bulk water. Ion pairing and iodide concentration in these zones is probably driven by the reduced dielectric constant of water in confined space and by the relatively high polarizability of the iodide species. - Highlights: • Iodide sorption experiments were completed with a diverse array of clay minerals. • Iodide uptake trended with CEC and swamping electrolyte identity and concentration. • Results can be explained by considering the formation of ion pairs in clay interlayers

The Ageing Effect of Mechanical Joints on the Tyre/Joint Noises Monitored by a Control Vehicle Method without Traffic Disturbance

Directory of Open Access Journals (Sweden)

C. K. Wong

2013-01-01

Full Text Available This paper studies the ageing effect of mechanical joints reflecting from the tyre/joint impacting noise by measuring the vehicle structure-borne noise change. Field data is collected applying two measurement methods suitable for newly installed and existing old expansion joints. The measurement methodology is improved by designing and applying a trailer for equipment installation. The main advantage of this method is not to disturb existing traffic by lane closure for measurement. Field measurements were conducted regularly for a study period up to 16 months after new joint replacement to monitor the variation of the structure-borne noise change inside a test vehicle while passing through mechanical joints. Empirical relationship is developed based on the field data of the roadside airborne noise change and the vehicle structure-borne noise change. The roadside tyre/joint noises could be converted using calibrated empirical formula. Key result findings include the following. (1 The vehicle structure-borne noise change is found smallest during the 3rd–6th months even lower than that measured when a new joint is installed. The structure-borne noise change then keeps increasing afterwards till the end of the study period. (2 Similar observations are found in all study cases incorporating various mechanical joint types and test vehicle types.

Stools - pale or clay-colored

Science.gov (United States)

... gov/ency/article/003129.htm Stools - pale or clay-colored To use the sharing features on this page, please enable JavaScript. Stools that are pale, clay, or putty-colored may be due to problems ...

Mars, clays and the origins of life

Science.gov (United States)

Hartman, Hyman

1989-01-01

To detect life in the Martian soil, tests were designed to look for respiration and photosynthesis. Both tests (labeled release, LR, and pyrolytic release, PR) for life in the Martian soils were positive. However, when the measurement for organic molecules in the soil of Mars was made, none were found. The interpretation given is that the inorganic constituents of the soil of Mars were responsible for these observations. The inorganic analysis of the soil was best fitted by a mixture of minerals: 60 to 80 percent clay, iron oxide, quartz, and soluble salts such as halite (NaCl). The minerals most successful in simulating the PR and LR experiments are iron-rich clays. There is a theory that considers clays as the first organisms capable of replication, mutation, and catalysis, and hence of evolving. Clays are formed when liquid water causes the weathering of rocks. The distribution of ions such as aluminum, magnesium, and iron play the role of bases in the DNA. The information was stored in the distribution of ions in the octahedral and tetrahedral molecules, but that they could, like RNA and DNA, replicate. When the clays replicated, each sheet of clay would be a template for a new sheet. The ion substitutions in one clay sheet would give rise to a complementary or similar pattern on the clay synthesized on its surface. It was theorized that it was on the surface of replicating iron-rich clays that carbon dioxide would be fixed in the light into organic acids such as formic or oxalic acid. If Mars had liquid water during a warm period in its past, clay formation would have been abundant. These clays would have replicated and evolved until the liquid water was removed due to cooling of Mars. It is entirely possible that the Viking mission detected life on Mars, but it was clay life that awaits the return of water to continue its evolution into life based on organic molecules.

Preparation of organophilic clays and polypropylene nano composites

International Nuclear Information System (INIS)

Lima, Martha Fogliato S.; Nascimento, Vinicius G. do; Lenz, Denise M.; Schenato, Flavia

2011-01-01

Polypropylene/montmorillonite nano composites were prepared by the melt intercalation technique. The clay was organically modified with different quaternary ammonium salts to obtain the organo clay. The modified clays with the quaternary ammonium salts were introduced in a polypropylene matrix with 3 wt. % of clay. The interlayer distance (d001) of the clay particles were obtained by X- ray diffraction and the thermal stability of the systems were investigated by thermogravimetry. The organo clay presence in the polymer matrix increased the degradation temperature in relation to the pure polymer. (author)

application of used engine oil on of used engine oil in soil on of ...

African Journals Online (AJOL)

eobe

Keywords: soil stabilization, used engine oil, s. 1. INTRODUCTION ... cement, lime, fly ash and a combination of ot additives is meant to ... California bearing ratio (CBR) of the soil. This p of the soil. ... range of silty-clay and sandy. CBR of ...

Implementation of geomechanical models for engineered clay barriers in multi-physic partial differential equation solvers

International Nuclear Information System (INIS)

Navarro, V.; Alonso, J.; Asensio, L.; Yustres, A.; Pintado, X.

2012-01-01

when using the mixed method. The constitutive formulation is implemented as a balance equation. This way, the user can freely implement models involving implicit relationships between variables. To illustrate the application of this method, we have analysed the implementation of a modified formulation of the Barcelona Expansive Model, a critical state model (CSM) of reference for expansive clays, as it is the case for bentonite clays for engineered barriers for radioactive nuclear spent fuel confinement. The tool developed was used to satisfactorily model the coupled hydro-mechanical problem of the free-swelling of a MX-80 bentonite disc. The bentonite sample had an initial dry density of 1600 kg/m 3 and a water content of 10% in mass. The initial dimensions of the disk were a height of 15.85 mm and a diameter of 100 mm. The hydration with deionised water applied on the top face of the sample was modelled with a saturation boundary condition. Figure 1 illustrates the case modelled and results obtained on pore water pressure and swelling of the sample at an intermediate time in the simulation. In addition, the modelling results have been compared with the experimental results obtained in the laboratory test carried out by B+TECH, as shown in Figure 2. In conclusion, the present proposal means a useful approach for the introduction of advanced Soil Mechanics models to the modelling of bentonite clays in multi-physics partial differential solvers. The use of it enables to overcome the limitations of some MPDES to integrate state functions defined implicitly. This makes it possible to combine the versatility of MPDES with powerful constitutive grounds. (authors)

Hydrogen isotope ratios of clay minerals constituting clay veins found in granitic rocks in Hiroshima Prefecture

International Nuclear Information System (INIS)

Kitagawa, Ryuji; Kakitani, Satoru; Kuroda, Yoshimatsu; Matsuo, Sadao; Suzuoki, Tetsuro.

1980-01-01

The deuterium content of the constitutional and interlayer water extracted from the clay minerals (illite, montmorillonite, interstratified illite-montmorillonite mineral, kaolinite, halloysite) constituting the clay veins found in the granitic rocks in Hiroshima Prefecture was measured. The clay minerals were heated at 270 deg C to extract the interlayer water, then heated to 1,400 or 1,500 deg C to extract the constitutional water. The deuterium content of the local surface water collected from sampling points was measured. In the clay veins formed along perpendicular joints, the constituent clay minerals change from lower to upper part: illite → montmorillonite → kaolinite → halloysite. The deuterium content values of the constitutional water for illite and montmorillonite were estimated to be -67 to -69% and -86 to -89%, respectively. The deuterium content values of the constitutional water for halloysite range from -68 to -80% and for kaolinite from -63 to -67%. (J.P.N.)

STABILISATION OF SILTY CLAY SOIL USING CHLORIDE

Directory of Open Access Journals (Sweden)

TAMADHER T. ABOOD

2007-04-01

Full Text Available The object of this paper is to investigate the effect of adding different chloride compounds including (NaCl, MgCl2, CaCl2 on the engineering properties of silty clay soil. Various amounts of salts (2%, 4%, and 8% were added to the soil to study the effect of salts on the compaction characteristics, consistency limits and compressive strength. The main findings of this study were that the increase in the percentage of each of the chloride compounds increased the maximum dry density and decrease the optimum moisture content. The liquid limit, plastic limit and plasticity index decreased with the increase in salt content. The unconfinedcompressive strength increased as the salt content increased.

Pedological ~cterization, Clay Mine:at~ and .~cation of,

African Journals Online (AJOL)

namely, very deep, well drained, dark reddish brown to dark brown, sandy clay loams and sandy clays on the steep convex slopes; very deep, well drained, dark brown to dark red, sandy clay loams and; sandy clays on the linear slopes; and very ...

Preparation and characterization of bentonite organo clay

International Nuclear Information System (INIS)

Bertagnolli, C.; Almeida Neto, A.F.; Silva, M.G.C.

2009-01-01

Bentonite clays organically modified have great potential use for environmental remediation, especially in the separation of organic compounds from the water. The aim of this work was the preparation of organophilic clays from 'Verde-Lodo' bentonite clay with the quaternary ammonium salts cetyl-pyridinium chloride and benzalkonium chloride. The materials obtained were characterized by XRD, thermogravimetric analyses, Helium picnometry, SEM and energy dispersive X-ray techniques. The results show consistently successful synthesis of the organoclay through the increase in the basal spacing, as well as salt elimination picks and presence of carbon and chlorine in the modified clays; they are inexistent elements in the natural clay. (author)

Treatment for cracked and permeable Houston clay

International Nuclear Information System (INIS)

Vipulanandan, C.; Leung, M.

1991-01-01

In this study, the treatability of a field clay (obtained from Houston, Texas) and a clay-sand mixture to reduce their hydraulic conductivity was evaluated. Remolded field clay and clay-sand mixture with and without methanol contamination were treated to reduce their hydraulic conductivity by permeating very dilute grout solutions. The concentration of sodium silicate in the grout solution was 8%, while the solid content in the cement grout was 0.3%. The hydraulic conductivity of permeable Houston clay (hydraulic conductivity >10 -5 cm/sec) could be reduced to less than 10 -7 cm/sec (U.S. EPA limit for soil barriers) by permeating with a selected combination of grout solutions

Stabilisation of Clay Soil with Lime and Melon Husk Ash for use in Farm Structures

Directory of Open Access Journals (Sweden)

I. S. Mohammed

2014-08-01

Full Text Available The rising cost of traditional stabilising agents and the need for economical utilisation of industrial and agricultural waste for beneficial engineering purposes has encouraged an investigation into the stabilization of clay soil with lime and melon husk ash. The chemical composition of the melon husk ash that was used in stabilising clay soil was determined. The clay soil was divided into two parts, one part was used to determine the index properties while the other part was treated at British Standard Light (BSL compaction energy with 0 %, 2 %, 4 %, 6 % and 8 % melon husk ash by dry weight of the soil and each was admixed with 2 %, 4 %, 6 % and 8 % lime. The stabilised clay soil was cured for 7, 14 and 28 days before the unconfined compressive strength were determined while the coefficients of permeability of the stabilised clay soil were also determined at 28 days of curing. The data obtained from the experiment was subjected to analysis of variance to examine the significance at 5% level. Results showed that the natural clay soil belong to A-7-6 or CH (clay of high plasticity in the American Association of State Highway Transportation Official (AASHTO and Unified Soil Classification System (1986. The chemical composition of the ash had aluminum oxide, iron oxide and silicon dioxide values of 18.5%, 2.82% and 51.24% respectively. The unconfined compressive strength and coefficient of permeability of the natural clay soil was determined to be 285 kN/m2 and 1.45 x 10-5 cm/s, respectively. Increase in melon husk ash and lime percent increases the unconfined compressive strength (UCS of the stabilised clay soil significantly (p < 0.05 and decrease the coefficient of permeability when compared with the natural clay soil. The peak values of unconfined compressive strength for 7, 14 and 28 days of curing are 1200 kN/m2, 1598 kN/m2 and 1695 kN/m2 respectively at 6% MHA and 8% lime content while the lowest value for coefficient of permeability was 0

Characterization of clay used for red ceramic fabrication

International Nuclear Information System (INIS)

Pereira, P.S.; Morais, A.S.C.; Caldas, T.C.C.; Monteiro, S.N.; Vieira, C.M.F.

2011-01-01

The objective of this work is to characterize a clay used in the red ceramics fabrication, from Campos dos Goytacazes north of the State of Rio de Janeiro. The clay was submitted for physical, chemical and mineralogical tests. The results showed that the clay has a high content of clay minerals with kaolinitic predominance, high loss on ignition and low flux oxides. It is recommended that this clay is mixed with non-plastic materials. (author)

Recovery of value-added products from the catalytic pyrolysis of waste tyre

Energy Technology Data Exchange (ETDEWEB)

Shah, J.; Jan, M.R.; Mabood, F. [Institute of Chemical Sciences, University of Peshawar, N.W.F.P., Peshawar 25120 (Pakistan)

2009-04-15

The influence of an acidic (SiO{sub 2}), basic (Al{sub 2}O{sub 3}) and mixture of acidic and basic (Al{sub 2}O{sub 3}: SiO{sub 2}) catalyst on the pyrolysis of used tyre rubber has been investigated. The yield of the derived gas, liquid and solid has been studied in term of the temperature, time and amount of catalyst. Oil fractions were analyzed by FTIR spectroscopy and gas chromatography with FID. Oil derived with Al{sub 2}O{sub 3} containing higher concentration of polar hydrocarbons (40%) and lower concentration of aliphatic hydrocarbons while 40% aliphatic hydrocarbons and 30% polar hydrocarbons were found in oil derived with SiO{sub 2}. A mixture of catalyst (Al{sub 2}O{sub 3}: SiO{sub 2}) gave equal concentration of aliphatic (35%) and polar (35%) hydrocarbons in oil. (author)

Encapsulation of Clay Platelets inside Latex Particles

NARCIS (Netherlands)

Voorn, D.J.; Ming, W.; Herk, van A.M.; Fernando, R.H.; Sung, Li-Piin

2009-01-01

We present our recent attempts in encapsulating clay platelets inside latex particles by emulsion polymerization. Face modification of clay platelets by cationic exchange has been shown to be insufficient for clay encapsulation, leading to armored latex particles. Successful encapsulation of

Sorption of Pu onto some kinds of clay

International Nuclear Information System (INIS)

Jia Haihong; Si Gaohua; Liu Wei; Yu Jing

2010-01-01

There are rich clay mines holding in one area, so it's necessary to know about these clays' sorption capacity to Pu, for building radioactive waste repository in the area. Distribution coefficients of Pu onto different clays were acquired in static method, with the result about 104. The size of clay is different, but the result of Kds is near. In addition, it's estimated how far Pu moves in the most rapid speed in the clay based on these Kids', disregarding the influence of Pu-colloid. In a word, as a kind of backfilling material clays in the area can effectively prevent Pu from moving to environment, and when designing the backfilling layer, it's not necessary to catch clays through NO.200 sieve, if only considering the influence of Kd. (authors)

Rheological characterization of nanocomposites Nylon 6/bentonite clay