The challenges of measuring in vivo total disc replacement (TDR) kinematics are well recognized, meaning that it is difficult to establish appropriate input conditions for wear simulation. Therefore it is desirable to ascertain the sensitivity of implant wear in vitro to perturbations of the kinematics and other testing parameters. It has previously been demonstrated in other metal-on-polyethylene joint replacements that cross-shear strongly influences wear rate. This study investigates this phenomenon by altering the phasing of the inputs by making the lag in the flexion-extension and lateral bend displacements zero. Further, the effect of an additional anterior-posterior shear, which has been reported in vivo, was investigated for two different TDR designs using an extra load or displacement input in addition to those prescribed by the standard ISO 18192-1. Altering the standard ISO 18192-1 waveform phasing significantly reduced the mean wear rate of the constrained polyethylene disc. The addition of an anterior-posterior input showed no significant change in the rate of wear for the constrained TDR but was increased for the unconstrained device. These data demonstrate the strong dependency of the wear in these types of joints to the input conditions as well as the devices design parameters. Hence, these factors should be given prime consideration when designing both the device itself and the assessment regime in which the construct is to be tested.
{"title":"Wear Simulation of Total Disc Arthroplasties: Sensitivity to Device Design and Test Parameters","authors":"P. Hyde, R. Vicars, J. Fisher, R. Hall","doi":"10.1520/JAI103497","DOIUrl":"https://doi.org/10.1520/JAI103497","url":null,"abstract":"The challenges of measuring in vivo total disc replacement (TDR) kinematics are well recognized, meaning that it is difficult to establish appropriate input conditions for wear simulation. Therefore it is desirable to ascertain the sensitivity of implant wear in vitro to perturbations of the kinematics and other testing parameters. It has previously been demonstrated in other metal-on-polyethylene joint replacements that cross-shear strongly influences wear rate. This study investigates this phenomenon by altering the phasing of the inputs by making the lag in the flexion-extension and lateral bend displacements zero. Further, the effect of an additional anterior-posterior shear, which has been reported in vivo, was investigated for two different TDR designs using an extra load or displacement input in addition to those prescribed by the standard ISO 18192-1. Altering the standard ISO 18192-1 waveform phasing significantly reduced the mean wear rate of the constrained polyethylene disc. The addition of an anterior-posterior input showed no significant change in the rate of wear for the constrained TDR but was increased for the unconstrained device. These data demonstrate the strong dependency of the wear in these types of joints to the input conditions as well as the devices design parameters. Hence, these factors should be given prime consideration when designing both the device itself and the assessment regime in which the construct is to be tested.","PeriodicalId":15057,"journal":{"name":"Journal of Astm International","volume":"19 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84246053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The steady boundary layer flow resulting from the stretching of a flat surface with a velocity proportional to the distance from a fixed point in a nanofluid under uniform heat and mass flux has been investigated numerically and using the nanofluid model proposed by Buongiorno (“Convective Transport in Nanofluids, ASME J. Heat Transfer, Vol. 128, 2006, pp. 240–250). The effects of Brownian motion and thermophoresis are incorporated in the model in order to obtain similarity solutions of the governing equations in terms of different parameters. The variation of the reduced Nusselt and reduced Sherwood numbers with the Prandtl number (Pr) and the Lewis number (Le) for various values of the Brownian motion parameter (Nb) and the thermophoresis parameter (Nt) is presented in tabular and graphical forms. It was found that the reduced Nusselt number is a decreasing function of each parameter (Pr, Le, Nb, and Nt), whereas the reduced Sherwood number is an increasing function of Nb and a decreasing function of Nt for each Le and Pr number.
利用Buongiorno提出的纳米流体模型(“纳米流体中的对流传输，ASME J. heat Transfer, Vol. 128, 2006, pp. 240-250”)，对均匀热量和质量通量下由平面表面拉伸产生的稳定边界层流动进行了数值研究。为了得到控制方程在不同参数下的相似解，在模型中考虑了布朗运动和热泳运动的影响。在不同的布朗运动参数(Nb)和热泳参数(Nt)值下，约简Nusselt数和约简Sherwood数随普朗特数(Pr)和路易斯数(Le)的变化以表格和图形形式给出。研究发现，约简Nusselt数是每个参数(Pr、Le、Nb和Nt)的递减函数，而约简Sherwood数是每个Le和Pr数的Nb递增函数和Nt递减函数。
{"title":"Boundary-Layer Flow of a Nanofluid past a Stretching Sheet under Uniform Heat and Mass Flux","authors":"W. Khan, I. Pop","doi":"10.1520/JAI104363","DOIUrl":"https://doi.org/10.1520/JAI104363","url":null,"abstract":"The steady boundary layer flow resulting from the stretching of a flat surface with a velocity proportional to the distance from a fixed point in a nanofluid under uniform heat and mass flux has been investigated numerically and using the nanofluid model proposed by Buongiorno (“Convective Transport in Nanofluids, ASME J. Heat Transfer, Vol. 128, 2006, pp. 240–250). The effects of Brownian motion and thermophoresis are incorporated in the model in order to obtain similarity solutions of the governing equations in terms of different parameters. The variation of the reduced Nusselt and reduced Sherwood numbers with the Prandtl number (Pr) and the Lewis number (Le) for various values of the Brownian motion parameter (Nb) and the thermophoresis parameter (Nt) is presented in tabular and graphical forms. It was found that the reduced Nusselt number is a decreasing function of each parameter (Pr, Le, Nb, and Nt), whereas the reduced Sherwood number is an increasing function of Nb and a decreasing function of Nt for each Le and Pr number.","PeriodicalId":15057,"journal":{"name":"Journal of Astm International","volume":"78 1","pages":"104363"},"PeriodicalIF":0.0,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88333724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The use of the oxygen storing capacity (OSC) of CeO2 to enhance the conditioning of engine exhaust is being explored as a means to reduce the harmful products of emission. A doping agent, Zr, is used to further improve ceria’s OSC and thermal stability. In this study, a high OSC endowed cerium-zirconium mixed-oxide (Ce0.6Zr0.4O2) three-way catalyst (TWC) was synthesized using a surfactant assisted co-precipitation method, and a stable suspension of the mixed oxide in diesel was prepared. The characterization of the mixed oxide and nanofuel was done using different analytical techniques, and the formation of a solid solution of the mixed oxide was confirmed. A stable dispersion of mixed oxide nanoparticles in diesel was achieved with the use of a mixed alkyl chain length surfactant. The thermal conductivity of the nanofuel did not show any significant increase with an increase in TWC concentration, and the calorific value of the nanofuel decreased. It is concluded that the cerium-zirconium mixed-oxide has a much higher OSC than pure ceria and could be potentially be used for better combustion of fuel in engines.
{"title":"Preparation and Characterization of Surfactant Coated Ce-Zr Nanoparticles and Nanofuel","authors":"R. Sharma, S. Kanagaraj","doi":"10.1520/JAI104429","DOIUrl":"https://doi.org/10.1520/JAI104429","url":null,"abstract":"The use of the oxygen storing capacity (OSC) of CeO2 to enhance the conditioning of engine exhaust is being explored as a means to reduce the harmful products of emission. A doping agent, Zr, is used to further improve ceria’s OSC and thermal stability. In this study, a high OSC endowed cerium-zirconium mixed-oxide (Ce0.6Zr0.4O2) three-way catalyst (TWC) was synthesized using a surfactant assisted co-precipitation method, and a stable suspension of the mixed oxide in diesel was prepared. The characterization of the mixed oxide and nanofuel was done using different analytical techniques, and the formation of a solid solution of the mixed oxide was confirmed. A stable dispersion of mixed oxide nanoparticles in diesel was achieved with the use of a mixed alkyl chain length surfactant. The thermal conductivity of the nanofuel did not show any significant increase with an increase in TWC concentration, and the calorific value of the nanofuel decreased. It is concluded that the cerium-zirconium mixed-oxide has a much higher OSC than pure ceria and could be potentially be used for better combustion of fuel in engines.","PeriodicalId":15057,"journal":{"name":"Journal of Astm International","volume":"1 1","pages":"104429"},"PeriodicalIF":0.0,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80460347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reactor dosimetry (RD) is a tool that provides data for neutron fluence accumulated over the reactor pressure vessel (RPV) during the reactor operation. This information, however, is not sufficient for RPV lifetime assessment. The life management of RPV is a multidisciplinary task. To assess whether the RPV steel properties at the current stage (for actual accumulated neutron fluence) of reactor operation are still 'safe enough,' the dependence of material properties on the fluence must be known; this is a task for material science (MS). Moreover, the mechanical loading over the RPV during normal operation and accidence have to be known, as well, for evaluation, if the RPV material integrity in this loading condition and existing cracks is provided. The crack loading path in terms of stress intensity factor is carried out by structural analyses (SA). Pressure and temperature distribution over RPV used in these analyses are obtained from a thermal hydraulic (TH) calculation. The conjunction of RD and other disciplines in RPV integrity assessment is analyzed in accordance with the FFP (fitness for purpose) approach. It could help to improve the efficiency in multi-disciplinary tasks solutions. (authors)
{"title":"Reactor Dosimetry and RPV Life Management","authors":"S. Belousov, Krassimira Ilieva, M. Mitev","doi":"10.1520/JAI104140","DOIUrl":"https://doi.org/10.1520/JAI104140","url":null,"abstract":"Reactor dosimetry (RD) is a tool that provides data for neutron fluence accumulated over the reactor pressure vessel (RPV) during the reactor operation. This information, however, is not sufficient for RPV lifetime assessment. The life management of RPV is a multidisciplinary task. To assess whether the RPV steel properties at the current stage (for actual accumulated neutron fluence) of reactor operation are still 'safe enough,' the dependence of material properties on the fluence must be known; this is a task for material science (MS). Moreover, the mechanical loading over the RPV during normal operation and accidence have to be known, as well, for evaluation, if the RPV material integrity in this loading condition and existing cracks is provided. The crack loading path in terms of stress intensity factor is carried out by structural analyses (SA). Pressure and temperature distribution over RPV used in these analyses are obtained from a thermal hydraulic (TH) calculation. The conjunction of RD and other disciplines in RPV integrity assessment is analyzed in accordance with the FFP (fitness for purpose) approach. It could help to improve the efficiency in multi-disciplinary tasks solutions. (authors)","PeriodicalId":15057,"journal":{"name":"Journal of Astm International","volume":"26 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85134600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ethanolysis of four different vegetable oils (sunflower, soybean, cotton seed, and used frying oil) was studied using sodium ethoxide as a catalyst. The ester preparation involved a two-step transesterification reaction, followed by purification. The effects of the mass ratio of catalyst to oil, the molar ratio of ethanol to oil, and the reaction temperature were studied on conversion of sunflower oil to optimize the reaction conditions in both stages. The rest of the vegetable oils were converted to ethyl esters under optimum reaction parameters. Ethyl esters of four different types of vegetable oils were blended with the diesel fuel at 2 %, 5 %, 10 %, and 20 %, on a volume basis. The experimental results showed that the densities and viscosities of the blends increased with the increase of biodiesel concentration in the fuel blend. Cold flow properties were negatively affected as ethyl ester content was increasing. Distillation characteristics and cetane indexes were not significantly altered. These results are promising, and ethyl esters can be seen as a viable fully renewable alternative to petroleum diesel.
{"title":"Fuel quality assessment of ethyl esters produced from vegetable oils and their blends with petroleum diesel.","authors":"G. Anastopoulos, S. Kalligeros, F. Zannikos","doi":"10.1520/JAI104528","DOIUrl":"https://doi.org/10.1520/JAI104528","url":null,"abstract":"Ethanolysis of four different vegetable oils (sunflower, soybean, cotton seed, and used frying oil) was studied using sodium ethoxide as a catalyst. The ester preparation involved a two-step transesterification reaction, followed by purification. The effects of the mass ratio of catalyst to oil, the molar ratio of ethanol to oil, and the reaction temperature were studied on conversion of sunflower oil to optimize the reaction conditions in both stages. The rest of the vegetable oils were converted to ethyl esters under optimum reaction parameters. Ethyl esters of four different types of vegetable oils were blended with the diesel fuel at 2 %, 5 %, 10 %, and 20 %, on a volume basis. The experimental results showed that the densities and viscosities of the blends increased with the increase of biodiesel concentration in the fuel blend. Cold flow properties were negatively affected as ethyl ester content was increasing. Distillation characteristics and cetane indexes were not significantly altered. These results are promising, and ethyl esters can be seen as a viable fully renewable alternative to petroleum diesel.","PeriodicalId":15057,"journal":{"name":"Journal of Astm International","volume":"1 1","pages":"104528"},"PeriodicalIF":0.0,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83111423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fusionless scoliosis growth rod systems pose many challenges to benchtop biomechanical testing. This study was conducted in order to develop a vertebrectomy model capable of evaluating shear/corrective reduction forces, anterior/posterior load sharing, and long term fatigue properties of these systems. Portions of ASTM F1717 and ISO 12189 were used to develop a custom dynamic construct. Results from the corrective/shear reduction force test demonstrate an expected reduced shear/corrective force at the completion of fatigue testing. Additionally, a bimodal force–displacement curve was demonstrated during confined static compression testing, indicating an anterior/posterior load sharing function of the system. Fatigue testing of the dynamic construct demonstrated the potential to develop a fatigue curve and endurance limit of a growth rod system. Moreover, fatigue testing replicated common in vivo failures. The complexities of scoliosis treatment make the definition of a standardized construct difficult. However, application of the current model can serve as a tool to understand the basic mechanical interactions in these complex systems.
{"title":"Vertebrectomy Model for the Mechanical Assessment of Fusionless Scoliosis Growth Rods","authors":"J. Shorez","doi":"10.1520/JAI103493","DOIUrl":"https://doi.org/10.1520/JAI103493","url":null,"abstract":"Fusionless scoliosis growth rod systems pose many challenges to benchtop biomechanical testing. This study was conducted in order to develop a vertebrectomy model capable of evaluating shear/corrective reduction forces, anterior/posterior load sharing, and long term fatigue properties of these systems. Portions of ASTM F1717 and ISO 12189 were used to develop a custom dynamic construct. Results from the corrective/shear reduction force test demonstrate an expected reduced shear/corrective force at the completion of fatigue testing. Additionally, a bimodal force–displacement curve was demonstrated during confined static compression testing, indicating an anterior/posterior load sharing function of the system. Fatigue testing of the dynamic construct demonstrated the potential to develop a fatigue curve and endurance limit of a growth rod system. Moreover, fatigue testing replicated common in vivo failures. The complexities of scoliosis treatment make the definition of a standardized construct difficult. However, application of the current model can serve as a tool to understand the basic mechanical interactions in these complex systems.","PeriodicalId":15057,"journal":{"name":"Journal of Astm International","volume":"102 1","pages":"103493"},"PeriodicalIF":0.0,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74428005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ASTM F2624-07 prescribes applying flexion/extension (FE), lateral bending (LB), and axial rotation (AR) moments to test and evaluate extra discal motion preserving implants (EDMPI), but parameters such as fixture design and load parameters are left to the user to define. A set of fixtures to conduct FE, LB, and AR testing rotation of EDMPI devices about a fixed center of rotation were developed by Aesculap Implant Systems. Their design was shared, and a set of these fixtures were manufactured and evaluated independently at Empirical Testing Corp. Testing was conducted to quantify the loads applied to an EDMPI in the FE and LB fixtures, determine whether results are frequency dependent, and evaluate whether EDMPI of different stiffnesses can be differentiated when using the fixtures. Miniature load cells were mounted to FE and LB fixtures to quantify load applied to an EDMPI during testing at several different applied loads and at two testing frequencies (2 Hz and 5 Hz). The load cells were replaced with cylindrical test specimens made of stainless steel, titanium, polyether ether ketone (PEEK), or a polyethylene cable slipped inside a polyurethane tube and the testing repeated. Results indicated that loads measured during FE testing were similar in magnitude to those recorded during LB testing but 90 degrees out of phase. No frequency effects were observed. Differences in displacement amplitude when testing the stainless steel, titanium, and PEEK specimens in FE and LB testing at both 2 Hz and 5 Hz were not discernable. The displacement amplitude of the polyethylene (PE) cord specimen was different than the other specimens, but no frequency effect was noted. The fixtures developed by Aesculap are a reasonable attempt to conduct EDMPI testing in FE, LB, and AR motions. Potential users of these fixtures should conduct further studies to determine whether their use is appropriate to test their specific EDMPI device.
{"title":"ASTM F2624—Evaluating Alternate Fixtures for Flexion/Extention, Lateral Bending, and Axial Rotation Testing of Extra Discal Motion Preserving Implants","authors":"M. Anderson, D. Lissy","doi":"10.1520/JAI103510","DOIUrl":"https://doi.org/10.1520/JAI103510","url":null,"abstract":"ASTM F2624-07 prescribes applying flexion/extension (FE), lateral bending (LB), and axial rotation (AR) moments to test and evaluate extra discal motion preserving implants (EDMPI), but parameters such as fixture design and load parameters are left to the user to define. A set of fixtures to conduct FE, LB, and AR testing rotation of EDMPI devices about a fixed center of rotation were developed by Aesculap Implant Systems. Their design was shared, and a set of these fixtures were manufactured and evaluated independently at Empirical Testing Corp. Testing was conducted to quantify the loads applied to an EDMPI in the FE and LB fixtures, determine whether results are frequency dependent, and evaluate whether EDMPI of different stiffnesses can be differentiated when using the fixtures. Miniature load cells were mounted to FE and LB fixtures to quantify load applied to an EDMPI during testing at several different applied loads and at two testing frequencies (2 Hz and 5 Hz). The load cells were replaced with cylindrical test specimens made of stainless steel, titanium, polyether ether ketone (PEEK), or a polyethylene cable slipped inside a polyurethane tube and the testing repeated. Results indicated that loads measured during FE testing were similar in magnitude to those recorded during LB testing but 90 degrees out of phase. No frequency effects were observed. Differences in displacement amplitude when testing the stainless steel, titanium, and PEEK specimens in FE and LB testing at both 2 Hz and 5 Hz were not discernable. The displacement amplitude of the polyethylene (PE) cord specimen was different than the other specimens, but no frequency effect was noted. The fixtures developed by Aesculap are a reasonable attempt to conduct EDMPI testing in FE, LB, and AR motions. Potential users of these fixtures should conduct further studies to determine whether their use is appropriate to test their specific EDMPI device.","PeriodicalId":15057,"journal":{"name":"Journal of Astm International","volume":"29 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82665345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper is a continuation of the authors’ previous work on the nucleate pool boiling heat transfer of nanofluids [Suriyawong, A. and Wongwises, S., “Nucleate pool boiling heat transfer characteristics of TiO2-water nanofluids at very low concentrations,” Exp. Therm. Fluid Sci., Vol. 34, No. 8, 2010, pp. 992–999.] This study presents new correlation for predicting heat transfer coefficient for nucleate pool boiling of TiO2-water nanofluids at several low concentrations. Unlike most previous studies, the proposed correlation consists of various relevant factors. Two horizontal circular plates made from copper and aluminum with different surface roughness values are used as heating surfaces. Because the calculation concerns with properties of nanofluids, this research uses various correlations from previous studies to find the properties of nanofluids and the best one is selected for the presentation. Compared with measured data of nucleate pool boiling of water and nanofluids from present and previous studies, it was found that the developed correlation could be used for prediction at a certain level.
本文是作者对纳米流体的核池沸腾传热研究的延续[Suriyawong, a .和Wongwises, S.， " tio2 -水纳米流体在极低浓度下的核池沸腾传热特性，" Exp. Therm。流体科学。，第34卷第8期，2010年，第992-999页。该研究为预测几种低浓度tio2 -水纳米流体的核池沸腾传热系数提供了新的相关性。与以往大多数研究不同的是，本文提出的相关性包含了各种相关因素。两个由不同表面粗糙度值的铜和铝制成的水平圆形板用作加热表面。由于计算涉及到纳米流体的性质，本研究使用了前人研究中的各种相关性来寻找纳米流体的性质，并选择了最好的一个进行展示。通过与现有研究和前人研究的水和纳米流体的核池沸腾的实测数据进行比较，发现所建立的相关性在一定程度上可以用于预测。
{"title":"Nucleate Pool Boiling Heat Transfer Correlation for TiO2-Water Nanofluids","authors":"A. Suriyawong, A. S. Dalkılıç, S. Wongwises","doi":"10.1520/JAI104409","DOIUrl":"https://doi.org/10.1520/JAI104409","url":null,"abstract":"This paper is a continuation of the authors’ previous work on the nucleate pool boiling heat transfer of nanofluids [Suriyawong, A. and Wongwises, S., “Nucleate pool boiling heat transfer characteristics of TiO2-water nanofluids at very low concentrations,” Exp. Therm. Fluid Sci., Vol. 34, No. 8, 2010, pp. 992–999.] This study presents new correlation for predicting heat transfer coefficient for nucleate pool boiling of TiO2-water nanofluids at several low concentrations. Unlike most previous studies, the proposed correlation consists of various relevant factors. Two horizontal circular plates made from copper and aluminum with different surface roughness values are used as heating surfaces. Because the calculation concerns with properties of nanofluids, this research uses various correlations from previous studies to find the properties of nanofluids and the best one is selected for the presentation. Compared with measured data of nucleate pool boiling of water and nanofluids from present and previous studies, it was found that the developed correlation could be used for prediction at a certain level.","PeriodicalId":15057,"journal":{"name":"Journal of Astm International","volume":"60 1","pages":"104409"},"PeriodicalIF":0.0,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88369767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reports the results of experiments aiming to identify the properties of ferrochromium slag when it is used as an artificial aggregate for preparation of granular layers of flexible pavements. The experimental program consisted of three stages: (1) study of the physical and chemical properties of slag, (2) leaching of heavy elements of slag in terms of environmental impact, (3) study of the mechanical properties of specimens made with ferrochromium slag and limestone as aggregate. In the laboratory, cylindrically prepared specimens were tested in a repeated load triaxial (RLT) test apparatus. In addition, particle size analysis, abrasion, frost resistance, compaction, CA bearing ratio, and leaching tests were performed on the materials prior to RLT testing. The results indicate that the physical and mechanical properties of air-cooled ferrochromium slag are as good as those of natural aggregates. It can be used as a base or sub-base material in highway pavements and as an embankment material. Furthermore, the use of the slag as aggregate in pavement layers reduces the requirement for natural aggregates and saves the existing natural resources.
{"title":"Use of Ferrochromium Slag as an Artificial Aggregate in Pavement Layers","authors":"A. Yilmaz, M. Karasahin","doi":"10.1520/JAI103666","DOIUrl":"https://doi.org/10.1520/JAI103666","url":null,"abstract":"This paper reports the results of experiments aiming to identify the properties of ferrochromium slag when it is used as an artificial aggregate for preparation of granular layers of flexible pavements. The experimental program consisted of three stages: (1) study of the physical and chemical properties of slag, (2) leaching of heavy elements of slag in terms of environmental impact, (3) study of the mechanical properties of specimens made with ferrochromium slag and limestone as aggregate. In the laboratory, cylindrically prepared specimens were tested in a repeated load triaxial (RLT) test apparatus. In addition, particle size analysis, abrasion, frost resistance, compaction, CA bearing ratio, and leaching tests were performed on the materials prior to RLT testing. The results indicate that the physical and mechanical properties of air-cooled ferrochromium slag are as good as those of natural aggregates. It can be used as a base or sub-base material in highway pavements and as an embankment material. Furthermore, the use of the slag as aggregate in pavement layers reduces the requirement for natural aggregates and saves the existing natural resources.","PeriodicalId":15057,"journal":{"name":"Journal of Astm International","volume":"31 1","pages":"103666"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73755152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cement-based solidification/stabilization (S/S) is a widely used source-controlled treatment method for contaminated sediments. Increasingly, the technology is being used to remediate sites that contain high molecular weight organic compounds. The low level of organic content in cement-based S/S mixtures often creates a need for organic additives in the mixtures in order to improve the level of sorption in the treatment process. Very little work has been published related to the quantification of the sorption of organic contaminants to cement-based S/S mixtures and the level of improvement afforded by additives such as fly ash and organoclays. The objective of this study is to examine the sorption levels of naphthalene to several cement-treated soil mixtures with and without organic additives (i.e., fly ash and organoclay) using batch testing. It is found that the sorption values of naphthalene vary but appear to be dependent on the amount of organic carbon present in the mixture. In order to assess the potential benefit of this improved sorption for field applications, contaminant migration modeling is performed using the results obtained. It is shown that cement-based S/S remediation systems can provide long-term protection against naphthalene contaminant migration, especially cement-based S/S mixtures with organoclay additives, for the assumptions considered in the modeling.
{"title":"Naphthalene Sorption to Organic Additives in Cement-Treated Soils","authors":"C. Lake, Jill Searle, Evan Bridson-Pateman","doi":"10.1520/JAI104302","DOIUrl":"https://doi.org/10.1520/JAI104302","url":null,"abstract":"Cement-based solidification/stabilization (S/S) is a widely used source-controlled treatment method for contaminated sediments. Increasingly, the technology is being used to remediate sites that contain high molecular weight organic compounds. The low level of organic content in cement-based S/S mixtures often creates a need for organic additives in the mixtures in order to improve the level of sorption in the treatment process. Very little work has been published related to the quantification of the sorption of organic contaminants to cement-based S/S mixtures and the level of improvement afforded by additives such as fly ash and organoclays. The objective of this study is to examine the sorption levels of naphthalene to several cement-treated soil mixtures with and without organic additives (i.e., fly ash and organoclay) using batch testing. It is found that the sorption values of naphthalene vary but appear to be dependent on the amount of organic carbon present in the mixture. In order to assess the potential benefit of this improved sorption for field applications, contaminant migration modeling is performed using the results obtained. It is shown that cement-based S/S remediation systems can provide long-term protection against naphthalene contaminant migration, especially cement-based S/S mixtures with organoclay additives, for the assumptions considered in the modeling.","PeriodicalId":15057,"journal":{"name":"Journal of Astm International","volume":"66 1","pages":"104302"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76962936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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