An experimental program was conducted to explore the impact of nanosilica on the microstructure and mechanical characteristics of cemented sandy soil.Cement agent included Portland cement type II.Cement content was 6%...An experimental program was conducted to explore the impact of nanosilica on the microstructure and mechanical characteristics of cemented sandy soil.Cement agent included Portland cement type II.Cement content was 6% by weight of the sandy soil.Nanosilica was added in percentages of 0%,4%,8% and 12% by weight of cement.Cylindrical samples were prepared with relative density of 80% and optimum water content and cured for 7 d,28 d and 90 d.Microstructure characteristics of cementnanosilica-sand mixtures after 90 d of curing have been explored using atomic force microscopy(AFM),scanning electron microscopy(SEM) and X-ray diffraction(XRD) tests.Effects of curing time on microstructure properties of cemented sandy soil samples with 0% and 8% nanosilica have been investigated using SEM test.Unconfined compression test(for all curing times) and compaction test were also performed.The SEM and AFM tests results showed that nanosilica contributes to enhancement of cemented sandy soil through yielding denser,more uniform structure.The XRD test demonstrated that the inclusion of nanosilica in the cemented soil increases the intensity of the calcium silicate hydrate(CSH) peak and decreases the intensity of the calcium hydroxide(CH) peak.The results showed that adding optimum percentages of nanosilica to cement-stabilized sandy soil enhances its mechanical and microstructure properties.展开更多
The presence of heavy metals（HMs） in particulate matters（PMs） particularly fine particles such as PM2.5 poses potential risk to the health of human being. The purpose of this study was to analyze the contents of H...The presence of heavy metals（HMs） in particulate matters（PMs） particularly fine particles such as PM2.5 poses potential risk to the health of human being. The purpose of this study was to analyze the contents of HMs in PM2.5 in the atmospheric monitoring stations in Isfahan city,Iran, in different seasons between March 2014 and March 2015 and their source identification using principle component analysis（PCA）. The samples of PM2.5 were taken using a high volume sampler in 7 monitoring stations located throughout the city and industrial zones since March 2014 to March 2015. The HMs content of the samples was measured using ICP-MS.The results showed that the concentrations of As, Cd and Ni were in a range of 23–36, 1–12,and 5–76 ng/m3 at all the stations which exceeded the US-EPA standards. Furthermore,the concentrations of Cr and Cu reached to 153 and 167 ng/m3 in some stations which were also higher than the standard levels. Depending on the potential sources of HMs, their concentration in PM2.5 through the various seasons was different. PCA illustrated that the different potential sources of HMs in the atmosphere, showing that the most important sources of HMs originated from fossil fuel combustion, abrasion of vehicle tires, industrial activities（e.g., iron and steel industries） and dust storms. Management and control of air pollution of industrial plants and vehicles are suggested for decreasing the risk of the HMs in the region.展开更多
AIM:To improve hepatic differentiation of human mesenchymal stem cell(MSC)using insulin growth factor 1(IGF-Ⅰ),which has important role in liver development,hepatocyte differentiation and function.METHODS:Bone marrow...AIM:To improve hepatic differentiation of human mesenchymal stem cell(MSC)using insulin growth factor 1(IGF-Ⅰ),which has important role in liver development,hepatocyte differentiation and function.METHODS:Bone marrow of healthy donors was aspirated from the iliac crest.The adherent cells expanded rapidly and were maintained with periodic passages until a relatively homogeneous population was established.The identification of these cells was carried out by immunophenotype analysis and differentiation potential into osteocytes and adipocytes.To effectively induce hepatic differentiation,we designed a protocol based on a combination of IGF-Ⅰ and liver specificfactors(hepatocyte growth factor,oncostatin M and dexamethasone).Morphological features,hepatic functions and cytological staining were assessed to evaluate transdifferentiation of human marrow-derived MSCs.RESULTS:Flow cytometric analysis and the differentiation potential into osteoblasts and adipocytes showed that more than 90% of human MSCs which were isolated and expanded were positive by specif ic markers and functional tests.Morphological assessment and evaluation of glycogen storage,albumin and α-feto protein expression,as well as albumin and urea secretion revealed a statistically signif icant difference between the experimental groups and control.CONCLUSION:In vitro differentiated MSCs using IGF-Ⅰwere able to display advanced liver metabolic functions,supporting the possibility of developing them as potential alternatives to primary hepatocytes.展开更多
Greater complexity is involved in the transient pressure analysis of horizontal oil wells in contrast to vertical wells,as the horizontal wells are considered entirely horizontal and parallel with the top and undernea...Greater complexity is involved in the transient pressure analysis of horizontal oil wells in contrast to vertical wells,as the horizontal wells are considered entirely horizontal and parallel with the top and underneath boundaries of the oil reserve.Therefore,there is an essential need to estimate productivity of horizontal wells accurately to examine the effectiveness of a horizontal well in terms of technical and economic prospects.In this work,novel and rigorous methods based on two different types of intelligent approaches including the artificial neural network(ANN)linked to the particle swarm optimization(PSO)tool are developed to precisely forecast the productivity of horizontal wells under pseudo-steady-state conditions.It was found that there is very good match between the modeling output and the real data taken from the literature,so that a very low average absolute error percentage is attained(e.g.,<0.82%).The developed techniques can be also incorporated in the numerical reservoir simulation packages for the purpose of accuracy improvement as well as better parametric sensitivity analysis.展开更多
Review of the literature related to the mixture of shredded tire and sand shows that,despite of the increase in shear strength due to addition of tire chips,granulated rubber causes reduction in shear strength of sand...Review of the literature related to the mixture of shredded tire and sand shows that,despite of the increase in shear strength due to addition of tire chips,granulated rubber causes reduction in shear strength of sand.In this study,the shear behavior of mixtures of fine-grained sand and 1-5 mm granulated rubber is investigated.Sixty direct shear tests were conducted on sandegranulated rubber mixtures with various rubber contents(0%,5%,10%,20% and 30%) at different relative densities(50%,70% and 90%) and different normal stresses(34.5 kPa,54.5 kPa,74.5 kPa and 104.5 kPa).The obtained results show that the granulated rubber improves the shear strength of fine-grained sand at medium relative density and low normal stress.The degree of improvement in shear strength is a function of rubber content,relative density and normal stress.The results show that at relative density of 50%,by adding 5% granulated rubber,the internal friction angle of sand increases from 35.1° to 39.2°.However,at relative densities of 70% and 90%,addition of granulated rubber to sand decreases its internal friction angle.The results also indicate that the behavior of sand becomes more ductile with increasing granulated rubber content.Adding granulated rubber leads to greater yielding strain and less tangent stiffness of sand.The maximum dilation angle decreases with the decrease in granulated rubber content.The stress ratio of sample at critical state(ψ= 0°) decreases with increasing granulated rubber content.展开更多
Nowadays artificial neural networkS （ANNs） with strong ability have been applied widely for prediction of non- linear phenomenon. In this work an optimized ANN with 7 inputs that consist of temperature, pressure, cr...Nowadays artificial neural networkS （ANNs） with strong ability have been applied widely for prediction of non- linear phenomenon. In this work an optimized ANN with 7 inputs that consist of temperature, pressure, critical temperature, critical pressure, density, molecular weight and acentric factor has been used for solubility predic- tion of three disperse dyes in supercritical carbon dioxide （SC-C02） and ethanol as co-solvent. It was shown how a multi-layer perceptron network can be trained to represent the solubility of disperse dyes in SC-C02. Numeric Sensitivity Analysis and Garson equation were utilized to find out the degree of effectiveness of different input variables on the efficiency of the proposed model. Results showed that our proposed ANN model has correlation coefficient, Nash-Sutcliffe model efficiency coefficient and discrepancy ratio about 0.998, 0.992, and 1.053 respectively.展开更多
Activated carbon has been proven to be an effective adsorbent for the recovery of a wide variety of metal ions from aqueous solutions. In this research, the activated hard shell of Iranian apricot stones was used for ...Activated carbon has been proven to be an effective adsorbent for the recovery of a wide variety of metal ions from aqueous solutions. In this research, the activated hard shell of Iranian apricot stones was used for gold recovery from electro-plating wastewater. The effect of parameters such as dose and particle size of adsorbent,pH, agitation speed of mixing on the gold recovery was investigated. The results showed that under the optimum operating conditions more than 98% of gold ions were adsorbed onto activated carbon after just 3 h. In addition, the adsorbed gold could be eluted from this adsorbent by improved striping method. The process involves contact of gold-laden adsorbent with a strong base at ambient temperatures followed by elution with an aqueous solution containing an organic solvent. It was found that activated hard shell of apricot stones has the potential to replace im ported commercial activated carbons in gold adsorption processes.展开更多
AIM： To evaluate demographic variables and visual outcomes, among patients with ocular injuries involving the posterior segment, managed with pars plana vitrectomy.· METHODS： The records of patients were studie...AIM： To evaluate demographic variables and visual outcomes, among patients with ocular injuries involving the posterior segment, managed with pars plana vitrectomy.· METHODS： The records of patients were studied retrospectively from March to September 2010, to determine the age, gender, place of occurrence of trauma, visual acuity, anatomical site, nature of injury,wound length, the presence of an afferent pupillary defect, and the timing of vitrectomy. The Ocular Trauma Score was measured. The minimum follow-up from presentation was 6mo.·RESULTS： Ninety patients（77 males, 13 females）, with a mean age of 32.7 ±15.8y were included over the 6-month period. The majority of cases occurred in the workplace（47 patients）, followed by home（14 patients）.The mean visual acuity（log MAR） of patients significantly improved from 2.36 ±0.72 preoperatively to 1.50 ±1.14 postoperatively. Twenty-three patients had preoperative vision better than 2.0 log MAR, the postoperative visual acuity was significantly better among these patients than patients with worse than 2.0 log MAR（P 〈0.001）. Visual improvement between groups with early vitrectomy（〉7d）and delayed vitrectomy（〉7d） was not significantly different（P =0.66）. Postoperative visual acuity was not significantly different between patients with injury in Zone I and II（P =0.64）, but patients with injury in Zone III had significantly poorer visual acuity（P =0.02）. Patients with relative afferent pupillary defect had significantly poorer postoperative visual acuity（P =0.02）. Preoperative visual acuity, the difference of preoperative and postoperative visual acuity, and postoperative visualacuity were significantly different between groups with different ocular trauma scores（P〈 0.001）.·CONCLUSION： Trauma is more likely to occur in men under 40 y of age and in the workplace. The favorable final visual outcome is associated with the absence of afferent pupillary defect, ocular trauma score and presenting visual acuity展开更多
Determining the adsorption of shale gas on complex surfaces remains a challenge in molecular simulation studies.Difficulties essentially stem from the need to create a realistic shale structure model in terms of miner...Determining the adsorption of shale gas on complex surfaces remains a challenge in molecular simulation studies.Difficulties essentially stem from the need to create a realistic shale structure model in terms of mineral heterogeneityand multiplicity.Moreover,precise characterization of the competitive adsorption of hydrogen andmethane in shale generally requires the experimental determination of the related adsorptive capacity.In thisstudy,the adsorption of adsorbates,methane(CH_(4)),and hydrogen(H_(2))on heterogeneous shale surface modelsof Kaolinite,Orthoclase,Muscovite,Mica,C_(60),and Butane has been simulated in the frame of a moleculardynamic’s numerical technique.The results show that these behaviors are influenced by pressure and potentialenergy.On increasing the pressure from 500 to 2000 psi,the sorption effect for CH_(4)significantly increasesbut shows a decline at a certain stage(if compared to H_(2)).The research findings also indicate that raw shalehas a higher capacity to adsorb CH_(4)compared to hydrogen.However,in shale,this difference is negligible.展开更多
We study Privacy Pools,a novel smart contract-based privacy-enhancing protocol.The protocol introduces a mechanism for users to reveal certain properties of their transaction without having to reveal the transaction i...We study Privacy Pools,a novel smart contract-based privacy-enhancing protocol.The protocol introduces a mechanism for users to reveal certain properties of their transaction without having to reveal the transaction itself.The core concept involves allowing users to publish a zero-knowledge proof,demonstrating that their funds(do not)originate from known(un-)lawful sources,without publicly revealing their entire transaction history.This is achieved by proving membership in custom association sets,which are designed to demonstrate compliance with regulatory frameworks or social consensus.We illustrate how this mechanism can create a separating equilibrium between compliant and non-compliant withdrawals.Our work describes the technical underpinnings,incentives,and broader implications of this mechanism,highlighting how Privacy Pools-like protocols can create more private yet compliant blockchain transactions.展开更多
AIM:To assess the hepatic changes after induction of different periods of renal ischemia. METHODS:Rats were subjected to either sham operation or ischemia (30,45 and 60 min) followed by 60 min reperfusion. Liver and r...AIM:To assess the hepatic changes after induction of different periods of renal ischemia. METHODS:Rats were subjected to either sham operation or ischemia (30,45 and 60 min) followed by 60 min reperfusion. Liver and renal functional indices were measured. Hepatic glutathione (GSH) and ferric reducing antioxidant power levels and the concentration of interleukin (IL)-10 and tumor necrosis factor (TNF-α) were evaluated. Portions of liver and kidney tissues were fixed for histological evaluation. RESULTS:Forty-five minutes renal ischemia followed by 60 min reperfusion caused significant changes in liver structure and a significant reduction in renalfunction. These rats showed a significant decrease in liver GSH,as well as a significant increase in TNF-α and IL-10 concentrations. These results demonstrated that renal ischemia caused changes in liver histology,function,oxidative stress and inflammatory status,which led to a reduction in hepatic antioxidant capacity. With 30 min ischemia,the magnitude of these changes was less than those with 45 or 60 min ischemia.CONCLUSION:A minimum of 45 min ischemia is needed to study the effects of renal injury on the liver as a remote organ.展开更多
AIM: To improve the isolation and expansion of human marrow-derived mesenchymal stem cells (MSCs) based on rat samples. METHODS: Based on the fact that rat MSCs are relatively easy to obtain from a small aspirate, bo... AIM: To improve the isolation and expansion of human marrow-derived mesenchymal stem cells (MSCs) based on rat samples. METHODS: Based on the fact that rat MSCs are relatively easy to obtain from a small aspirate, bone marrow-derived MSCs from rat were cultured and characterized to set up the different protocols used in this study. Then, accordingly, almost the same protocols were performed on human healthy bone marrow samples, after obtaining approval of the ethics committee and gaining informed consent. We used different protocols and culture conditions, including the type of basal media and the culture composition. The MSCs were characterized by immunophenotyping and differentiation. RESULTS: There was no difference in morphology and proliferation capacity between different culture media at the first passage. During the 5-7th passages, the cells gradually lost their morphology and proliferation potential on Dulbecco’s modified Eagle’s medium (DMEM) high glucose and α modified Eagle’s medium. Although the cells expanded rapidly for up to 10 passages on DMEM low glucose containing 10% to 15% fetal calf serum (FCS), their proliferation was arrested without change in morphology and differentiation capacity at the third passage on 5% FCS. Flow cytometric analysis and functional tests confirmed that more than 90% of marrow cells which were isolated and expanded by our selective protocols were MSCs. CONCLUSION: We improved the isolation and expansion of human bone marrow derived MSCs, based on rat sample experiments, for further experimental and clinical use.展开更多
The Sarvak Formation is the second major oil-bearing reservoir in the south and south west of Iran. The Middle Cretaceous Sarvak formation in the Zagros Mountains (Zagros Basin) is mainly composed of carbonate sequenc...The Sarvak Formation is the second major oil-bearing reservoir in the south and south west of Iran. The Middle Cretaceous Sarvak formation in the Zagros Mountains (Zagros Basin) is mainly composed of carbonate sequences. Based on facies studied, thirteen microfacies were recognized in the studied area, which were categorized in the three facies groups: including inner ramp, mid ramp and outer ramp. Evidences such as the gradual changes in the facies (basin slope), the absence of extensive uninterrupted barrier reef, the lack of calciturbidite and gravity sediments as well as the high proportion of grain-supported indicated that the Sarvak Formation was deposited in the ramp like depositional system, particularly on an inner ramp setting. Inner ramp facies group is the principal setting and subdivided to tidal flat, restricted and unrestricted lagoon as well as shoal sub-environments.展开更多
In this paper,two smoothed particle hydrodynamics(SPH)models,namely SPH-W and SPH-C were used to evaluate the motion response of a point absorber wave energy converter(WEC).In the SPH-W model,a long wave flume was con...In this paper,two smoothed particle hydrodynamics(SPH)models,namely SPH-W and SPH-C were used to evaluate the motion response of a point absorber wave energy converter(WEC).In the SPH-W model,a long wave flume was constructed and a long simulation was performed to obtain the motion response of the WEC.In the SPH-C model,the SPH method is only used to find the hydrodynamic coefficients of the device by analysing a few seconds of free-decaying motion of WEC in calm water in a much smaller numerical flume.Then,these coefficients were inserted in the equation of motion of a heaving WEC that was solved using a 4th order Runge-Kutta(ODE45)solver in MATLAB.First,the energy conservation property of the WCSPH model was examined through a standing wave benchmark test.Then,the wavepoint absorber interaction was simulated.While the simulation time for SPH-C model is much smaller than that of SPH-W,it gave almost similar results for the motion response of WEC.These two models were used to evaluate the effects of the control force and the draft of a cone-cylinder point absorber on its hydrodynamic responses.The results showed that compared to the effect of the supplementary inertia,changes in the draft of the WEC have a small influence on its hydrodynamic responses.The buoy draft has an inverse relationship with both added mass and damping coefficients.However,increasing the supplementary mass increases the added mass and decreases the hydrodynamic damping coefficients.展开更多
The appropriate production of liquefied natural gas(LNG)with least consuming energy and maximum efficiency is quite important.In this paper,LNG production cycle by means of APCI Process has been studied.Energy equilib...The appropriate production of liquefied natural gas(LNG)with least consuming energy and maximum efficiency is quite important.In this paper,LNG production cycle by means of APCI Process has been studied.Energy equilibrium equations and exergy equilibrium equations of each equipment in the APCI cycle were established.The equipments are described using rigorous thermodynamics and no significant simplification is assumed.Taken some operating parameters as key parameters,influences of these parameters on coefficient of performance(COP)and exergy efficiency of the cascading cycle were analyzed.The results indicate that COP and exergy efficiency will be improved with the increasing of the inlet pressure of MR(mixed refrigerant)compressors,the decreasing of the NG and MR after precooling process,outlet pressure of turbine,inlet temperature of MR compressor and NG temperature after cooling in main cryogenic heat exchanger(MCHE).The COP and exergy efficiency of the APCI cycle will be above 2% and 40%,respectively,after optimizing the key parameters.展开更多
AIM: To study the distribution of ocular higher-order aberrations(HOAs) and mesopic pupil size in individuals screened for refractive surgery. · METHODS: Ocular HOAs and mesopic pupil size were studied in 2 458 e...AIM: To study the distribution of ocular higher-order aberrations(HOAs) and mesopic pupil size in individuals screened for refractive surgery. · METHODS: Ocular HOAs and mesopic pupil size were studied in 2 458 eyes of 1 240 patients with myopia, myopic astigmatism and compound myopic astigmatism and 215 eyes of 110 patients with hyperopia, hyperopic astigmatism and compound hyperopic astigmatism using the Zywave aberrometer (Busch& Lomb). All patients had correctable refractive errors without a history of refractive surgery or underlying diseases. Root-mean-square values of HOAs, total spherical aberration, total coma and mesopic pupil size were analyzed. Ocular HOAs were measured across a ≥ 6.0 mm pupil, and pupil size measurements were performed under the mesopic condition. · RESULTS: The mean values of HOAs, total spherical aberration and total coma in the myopic group were 0.369 μm, ±0.233, 0.133±0.112μm and 0.330±0.188μm, respectively. In the hyperopic group the mean values of HOAs, total spherical aberration and total coma were 0.418μm±0.214, 0.202±0.209μm and 0.343±0.201μm, respectively. Hyperopes showed greater total HOAs (P <0.01) and total spherical aberration (P <0.01) compared to myopes. In age-matched analysis, only the amount of total spherical aberration was higher in the hyperopic group (P =0.05). Mesopic pupil size in the myopic group was larger (P ≤0.05). · CONCLUSION: The results suggested that significant levels of HOAs were found in both groups which are important for planning refractive surgeries on Iranians. There were significantly higher levels of total spherical aberration in hyperopes compared to myopes. Mesopic pupil size was larger in myopic group.展开更多
Retaining walls have been used in many construction projects such as for road and inclined surfaces protection. The damage caused by an earthquake depends on the fundamental frequency, amplitude and the duration of th...Retaining walls have been used in many construction projects such as for road and inclined surfaces protection. The damage caused by an earthquake depends on the fundamental frequency, amplitude and the duration of the seismic motion. These parameters strongly depend on the seismic properties of the layers that are near the surface. In the study of retaining walls, in addition to the infl uence of soil, the infl uence of topography is also important. In the present study, site response analysis is performed by using fi nite element software PLAXIS to obtain the eff ect of various factors such as embedded length of the sheet pile, underground water table, length and angle of the nail, shear wave velocity of soil on site eff ect and dynamic response. Moreover, for better understanding of the eff ect of the above parameters, the stability analysis was performed by using shear reduction method. The results show that an increase in the embedded length of the sheet pile and the length of nailing causes an increase in the amplifi cation factor. Moreover, for shear-wave velocity in the range of 200- 600 m/s, the amplifi cation factor increases with increase of the shear-wave velocity due to the decrease of nonlinear behavior.展开更多
Self-nanoemulsifying systems(SNEs) have excellent ability to improve the solubility ofpoorly water-soluble drugs(PWSD). However, SNEs are likely to be degraded in gastroin-testinal(GIT) when their surface is recognize...Self-nanoemulsifying systems(SNEs) have excellent ability to improve the solubility ofpoorly water-soluble drugs(PWSD). However, SNEs are likely to be degraded in gastroin-testinal(GIT) when their surface is recognized by lipase/co-lipase enzyme complex, result-ing in rapid release and precipitation of encapsulated drugs. The precipitates are then cap-tured and removed by intestinal mucus, reducing the delivery efficacy of SNEs. Herein, theamphiphilic polymer Pluronic? F127 was incorporated into long and short-chain triglyc-erides(LCT, SCT) based SNEs to diminish the recognition and therefore minimized theirdegradation by enzymes and clearance by mucus. The SNEs were characterized in termsof particle size, zeta potential and stability. Ex vivo multiple particles tracking studies wereperformed by adding particle solution into fresh rat mucus. Cellular uptake of SNEs wereconducted by using E12 cells, the absorption and distribution in small intestine were alsostudied after oral administration in male Sprague-Dawley(SD) rats. The in vitro digestionrate of SNEs were found to be in following order SCT-SNE > SCT-F127-SNE > LCT-SNE > LCT-F127-SNE. Moreover, the LCT-F127-SNE was found to be most effective in enhancing cellularuptake, resulting in 3.5-fold, 2.1-fold and 1.7-fold higher than that of SCT-SNE, LCT-SNE andSCT-F127-SNE, respectively. After incubating the SNE with E12 cells, the LCT-F127-SNE ex-hibited the highest amount regarding both mucus penetration and cellular uptake, with anuptake amount number(via bicinchoninic acid(BCA) analysis) of 3.5-fold, 2.1-fold and 1.7-fold higher than that of SCT-SNE, LCT-SNE and SCT-F127-SNE, respectively. The in vivo results revealed that orally administered LCT-F127-SNE could significantly increase the bioavailability of Cyclosporine A(CsA), which was approximately 2.43-fold, 1.33-fold and 1.80-fold higher than that of SCT-SNE, SCT-F127-SNE and LCT-SNE, respectively. We address in this work that F127-modified SNEs have potentials to improve oral drug absorption by significan展开更多
文摘An experimental program was conducted to explore the impact of nanosilica on the microstructure and mechanical characteristics of cemented sandy soil.Cement agent included Portland cement type II.Cement content was 6% by weight of the sandy soil.Nanosilica was added in percentages of 0%,4%,8% and 12% by weight of cement.Cylindrical samples were prepared with relative density of 80% and optimum water content and cured for 7 d,28 d and 90 d.Microstructure characteristics of cementnanosilica-sand mixtures after 90 d of curing have been explored using atomic force microscopy(AFM),scanning electron microscopy(SEM) and X-ray diffraction(XRD) tests.Effects of curing time on microstructure properties of cemented sandy soil samples with 0% and 8% nanosilica have been investigated using SEM test.Unconfined compression test(for all curing times) and compaction test were also performed.The SEM and AFM tests results showed that nanosilica contributes to enhancement of cemented sandy soil through yielding denser,more uniform structure.The XRD test demonstrated that the inclusion of nanosilica in the cemented soil increases the intensity of the calcium silicate hydrate(CSH) peak and decreases the intensity of the calcium hydroxide(CH) peak.The results showed that adding optimum percentages of nanosilica to cement-stabilized sandy soil enhances its mechanical and microstructure properties.
基金financially supported by the Fundamental Research Funds for the central University,China University of Geosciences(Wuhan)(No.CUG150602)the International collaboration project funded by the China University of Geosciences(Wuhan)
文摘The presence of heavy metals（HMs） in particulate matters（PMs） particularly fine particles such as PM2.5 poses potential risk to the health of human being. The purpose of this study was to analyze the contents of HMs in PM2.5 in the atmospheric monitoring stations in Isfahan city,Iran, in different seasons between March 2014 and March 2015 and their source identification using principle component analysis（PCA）. The samples of PM2.5 were taken using a high volume sampler in 7 monitoring stations located throughout the city and industrial zones since March 2014 to March 2015. The HMs content of the samples was measured using ICP-MS.The results showed that the concentrations of As, Cd and Ni were in a range of 23–36, 1–12,and 5–76 ng/m3 at all the stations which exceeded the US-EPA standards. Furthermore,the concentrations of Cr and Cu reached to 153 and 167 ng/m3 in some stations which were also higher than the standard levels. Depending on the potential sources of HMs, their concentration in PM2.5 through the various seasons was different. PCA illustrated that the different potential sources of HMs in the atmosphere, showing that the most important sources of HMs originated from fossil fuel combustion, abrasion of vehicle tires, industrial activities（e.g., iron and steel industries） and dust storms. Management and control of air pollution of industrial plants and vehicles are suggested for decreasing the risk of the HMs in the region.
基金Supported by A grant from Stem Cell Organization:www.stem cell.ir
文摘AIM:To improve hepatic differentiation of human mesenchymal stem cell(MSC)using insulin growth factor 1(IGF-Ⅰ),which has important role in liver development,hepatocyte differentiation and function.METHODS:Bone marrow of healthy donors was aspirated from the iliac crest.The adherent cells expanded rapidly and were maintained with periodic passages until a relatively homogeneous population was established.The identification of these cells was carried out by immunophenotype analysis and differentiation potential into osteocytes and adipocytes.To effectively induce hepatic differentiation,we designed a protocol based on a combination of IGF-Ⅰ and liver specificfactors(hepatocyte growth factor,oncostatin M and dexamethasone).Morphological features,hepatic functions and cytological staining were assessed to evaluate transdifferentiation of human marrow-derived MSCs.RESULTS:Flow cytometric analysis and the differentiation potential into osteoblasts and adipocytes showed that more than 90% of human MSCs which were isolated and expanded were positive by specif ic markers and functional tests.Morphological assessment and evaluation of glycogen storage,albumin and α-feto protein expression,as well as albumin and urea secretion revealed a statistically signif icant difference between the experimental groups and control.CONCLUSION:In vitro differentiated MSCs using IGF-Ⅰwere able to display advanced liver metabolic functions,supporting the possibility of developing them as potential alternatives to primary hepatocytes.
文摘Greater complexity is involved in the transient pressure analysis of horizontal oil wells in contrast to vertical wells,as the horizontal wells are considered entirely horizontal and parallel with the top and underneath boundaries of the oil reserve.Therefore,there is an essential need to estimate productivity of horizontal wells accurately to examine the effectiveness of a horizontal well in terms of technical and economic prospects.In this work,novel and rigorous methods based on two different types of intelligent approaches including the artificial neural network(ANN)linked to the particle swarm optimization(PSO)tool are developed to precisely forecast the productivity of horizontal wells under pseudo-steady-state conditions.It was found that there is very good match between the modeling output and the real data taken from the literature,so that a very low average absolute error percentage is attained(e.g.,<0.82%).The developed techniques can be also incorporated in the numerical reservoir simulation packages for the purpose of accuracy improvement as well as better parametric sensitivity analysis.
文摘Review of the literature related to the mixture of shredded tire and sand shows that,despite of the increase in shear strength due to addition of tire chips,granulated rubber causes reduction in shear strength of sand.In this study,the shear behavior of mixtures of fine-grained sand and 1-5 mm granulated rubber is investigated.Sixty direct shear tests were conducted on sandegranulated rubber mixtures with various rubber contents(0%,5%,10%,20% and 30%) at different relative densities(50%,70% and 90%) and different normal stresses(34.5 kPa,54.5 kPa,74.5 kPa and 104.5 kPa).The obtained results show that the granulated rubber improves the shear strength of fine-grained sand at medium relative density and low normal stress.The degree of improvement in shear strength is a function of rubber content,relative density and normal stress.The results show that at relative density of 50%,by adding 5% granulated rubber,the internal friction angle of sand increases from 35.1° to 39.2°.However,at relative densities of 70% and 90%,addition of granulated rubber to sand decreases its internal friction angle.The results also indicate that the behavior of sand becomes more ductile with increasing granulated rubber content.Adding granulated rubber leads to greater yielding strain and less tangent stiffness of sand.The maximum dilation angle decreases with the decrease in granulated rubber content.The stress ratio of sample at critical state(ψ= 0°) decreases with increasing granulated rubber content.
文摘Nowadays artificial neural networkS （ANNs） with strong ability have been applied widely for prediction of non- linear phenomenon. In this work an optimized ANN with 7 inputs that consist of temperature, pressure, critical temperature, critical pressure, density, molecular weight and acentric factor has been used for solubility predic- tion of three disperse dyes in supercritical carbon dioxide （SC-C02） and ethanol as co-solvent. It was shown how a multi-layer perceptron network can be trained to represent the solubility of disperse dyes in SC-C02. Numeric Sensitivity Analysis and Garson equation were utilized to find out the degree of effectiveness of different input variables on the efficiency of the proposed model. Results showed that our proposed ANN model has correlation coefficient, Nash-Sutcliffe model efficiency coefficient and discrepancy ratio about 0.998, 0.992, and 1.053 respectively.
文摘Activated carbon has been proven to be an effective adsorbent for the recovery of a wide variety of metal ions from aqueous solutions. In this research, the activated hard shell of Iranian apricot stones was used for gold recovery from electro-plating wastewater. The effect of parameters such as dose and particle size of adsorbent,pH, agitation speed of mixing on the gold recovery was investigated. The results showed that under the optimum operating conditions more than 98% of gold ions were adsorbed onto activated carbon after just 3 h. In addition, the adsorbed gold could be eluted from this adsorbent by improved striping method. The process involves contact of gold-laden adsorbent with a strong base at ambient temperatures followed by elution with an aqueous solution containing an organic solvent. It was found that activated hard shell of apricot stones has the potential to replace im ported commercial activated carbons in gold adsorption processes.
文摘AIM： To evaluate demographic variables and visual outcomes, among patients with ocular injuries involving the posterior segment, managed with pars plana vitrectomy.· METHODS： The records of patients were studied retrospectively from March to September 2010, to determine the age, gender, place of occurrence of trauma, visual acuity, anatomical site, nature of injury,wound length, the presence of an afferent pupillary defect, and the timing of vitrectomy. The Ocular Trauma Score was measured. The minimum follow-up from presentation was 6mo.·RESULTS： Ninety patients（77 males, 13 females）, with a mean age of 32.7 ±15.8y were included over the 6-month period. The majority of cases occurred in the workplace（47 patients）, followed by home（14 patients）.The mean visual acuity（log MAR） of patients significantly improved from 2.36 ±0.72 preoperatively to 1.50 ±1.14 postoperatively. Twenty-three patients had preoperative vision better than 2.0 log MAR, the postoperative visual acuity was significantly better among these patients than patients with worse than 2.0 log MAR（P 〈0.001）. Visual improvement between groups with early vitrectomy（〉7d）and delayed vitrectomy（〉7d） was not significantly different（P =0.66）. Postoperative visual acuity was not significantly different between patients with injury in Zone I and II（P =0.64）, but patients with injury in Zone III had significantly poorer visual acuity（P =0.02）. Patients with relative afferent pupillary defect had significantly poorer postoperative visual acuity（P =0.02）. Preoperative visual acuity, the difference of preoperative and postoperative visual acuity, and postoperative visualacuity were significantly different between groups with different ocular trauma scores（P〈 0.001）.·CONCLUSION： Trauma is more likely to occur in men under 40 y of age and in the workplace. The favorable final visual outcome is associated with the absence of afferent pupillary defect, ocular trauma score and presenting visual acuity
基金PETRONAS Research fund(PRF)under PETRONAS Teknologi Transfer(PTT)Pre-Commercialization—External:YUTP-PRG Cycle 2022(015PBC-020).
文摘Determining the adsorption of shale gas on complex surfaces remains a challenge in molecular simulation studies.Difficulties essentially stem from the need to create a realistic shale structure model in terms of mineral heterogeneityand multiplicity.Moreover,precise characterization of the competitive adsorption of hydrogen andmethane in shale generally requires the experimental determination of the related adsorptive capacity.In thisstudy,the adsorption of adsorbates,methane(CH_(4)),and hydrogen(H_(2))on heterogeneous shale surface modelsof Kaolinite,Orthoclase,Muscovite,Mica,C_(60),and Butane has been simulated in the frame of a moleculardynamic’s numerical technique.The results show that these behaviors are influenced by pressure and potentialenergy.On increasing the pressure from 500 to 2000 psi,the sorption effect for CH_(4)significantly increasesbut shows a decline at a certain stage(if compared to H_(2)).The research findings also indicate that raw shalehas a higher capacity to adsorb CH_(4)compared to hydrogen.However,in shale,this difference is negligible.
文摘We study Privacy Pools,a novel smart contract-based privacy-enhancing protocol.The protocol introduces a mechanism for users to reveal certain properties of their transaction without having to reveal the transaction itself.The core concept involves allowing users to publish a zero-knowledge proof,demonstrating that their funds(do not)originate from known(un-)lawful sources,without publicly revealing their entire transaction history.This is achieved by proving membership in custom association sets,which are designed to demonstrate compliance with regulatory frameworks or social consensus.We illustrate how this mechanism can create a separating equilibrium between compliant and non-compliant withdrawals.Our work describes the technical underpinnings,incentives,and broader implications of this mechanism,highlighting how Privacy Pools-like protocols can create more private yet compliant blockchain transactions.
基金Supported by A grant from Tehran Medical Sciences University
文摘AIM:To assess the hepatic changes after induction of different periods of renal ischemia. METHODS:Rats were subjected to either sham operation or ischemia (30,45 and 60 min) followed by 60 min reperfusion. Liver and renal functional indices were measured. Hepatic glutathione (GSH) and ferric reducing antioxidant power levels and the concentration of interleukin (IL)-10 and tumor necrosis factor (TNF-α) were evaluated. Portions of liver and kidney tissues were fixed for histological evaluation. RESULTS:Forty-five minutes renal ischemia followed by 60 min reperfusion caused significant changes in liver structure and a significant reduction in renalfunction. These rats showed a significant decrease in liver GSH,as well as a significant increase in TNF-α and IL-10 concentrations. These results demonstrated that renal ischemia caused changes in liver histology,function,oxidative stress and inflammatory status,which led to a reduction in hepatic antioxidant capacity. With 30 min ischemia,the magnitude of these changes was less than those with 45 or 60 min ischemia.CONCLUSION:A minimum of 45 min ischemia is needed to study the effects of renal injury on the liver as a remote organ.
基金Supported by A grant from Stem Cell Organization: www.stem-cell.ir
文摘 AIM: To improve the isolation and expansion of human marrow-derived mesenchymal stem cells (MSCs) based on rat samples. METHODS: Based on the fact that rat MSCs are relatively easy to obtain from a small aspirate, bone marrow-derived MSCs from rat were cultured and characterized to set up the different protocols used in this study. Then, accordingly, almost the same protocols were performed on human healthy bone marrow samples, after obtaining approval of the ethics committee and gaining informed consent. We used different protocols and culture conditions, including the type of basal media and the culture composition. The MSCs were characterized by immunophenotyping and differentiation. RESULTS: There was no difference in morphology and proliferation capacity between different culture media at the first passage. During the 5-7th passages, the cells gradually lost their morphology and proliferation potential on Dulbecco’s modified Eagle’s medium (DMEM) high glucose and α modified Eagle’s medium. Although the cells expanded rapidly for up to 10 passages on DMEM low glucose containing 10% to 15% fetal calf serum (FCS), their proliferation was arrested without change in morphology and differentiation capacity at the third passage on 5% FCS. Flow cytometric analysis and functional tests confirmed that more than 90% of marrow cells which were isolated and expanded by our selective protocols were MSCs. CONCLUSION: We improved the isolation and expansion of human bone marrow derived MSCs, based on rat sample experiments, for further experimental and clinical use.
文摘The Sarvak Formation is the second major oil-bearing reservoir in the south and south west of Iran. The Middle Cretaceous Sarvak formation in the Zagros Mountains (Zagros Basin) is mainly composed of carbonate sequences. Based on facies studied, thirteen microfacies were recognized in the studied area, which were categorized in the three facies groups: including inner ramp, mid ramp and outer ramp. Evidences such as the gradual changes in the facies (basin slope), the absence of extensive uninterrupted barrier reef, the lack of calciturbidite and gravity sediments as well as the high proportion of grain-supported indicated that the Sarvak Formation was deposited in the ramp like depositional system, particularly on an inner ramp setting. Inner ramp facies group is the principal setting and subdivided to tidal flat, restricted and unrestricted lagoon as well as shoal sub-environments.
文摘In this paper,two smoothed particle hydrodynamics(SPH)models,namely SPH-W and SPH-C were used to evaluate the motion response of a point absorber wave energy converter(WEC).In the SPH-W model,a long wave flume was constructed and a long simulation was performed to obtain the motion response of the WEC.In the SPH-C model,the SPH method is only used to find the hydrodynamic coefficients of the device by analysing a few seconds of free-decaying motion of WEC in calm water in a much smaller numerical flume.Then,these coefficients were inserted in the equation of motion of a heaving WEC that was solved using a 4th order Runge-Kutta(ODE45)solver in MATLAB.First,the energy conservation property of the WCSPH model was examined through a standing wave benchmark test.Then,the wavepoint absorber interaction was simulated.While the simulation time for SPH-C model is much smaller than that of SPH-W,it gave almost similar results for the motion response of WEC.These two models were used to evaluate the effects of the control force and the draft of a cone-cylinder point absorber on its hydrodynamic responses.The results showed that compared to the effect of the supplementary inertia,changes in the draft of the WEC have a small influence on its hydrodynamic responses.The buoy draft has an inverse relationship with both added mass and damping coefficients.However,increasing the supplementary mass increases the added mass and decreases the hydrodynamic damping coefficients.
文摘The appropriate production of liquefied natural gas(LNG)with least consuming energy and maximum efficiency is quite important.In this paper,LNG production cycle by means of APCI Process has been studied.Energy equilibrium equations and exergy equilibrium equations of each equipment in the APCI cycle were established.The equipments are described using rigorous thermodynamics and no significant simplification is assumed.Taken some operating parameters as key parameters,influences of these parameters on coefficient of performance(COP)and exergy efficiency of the cascading cycle were analyzed.The results indicate that COP and exergy efficiency will be improved with the increasing of the inlet pressure of MR(mixed refrigerant)compressors,the decreasing of the NG and MR after precooling process,outlet pressure of turbine,inlet temperature of MR compressor and NG temperature after cooling in main cryogenic heat exchanger(MCHE).The COP and exergy efficiency of the APCI cycle will be above 2% and 40%,respectively,after optimizing the key parameters.
文摘AIM: To study the distribution of ocular higher-order aberrations(HOAs) and mesopic pupil size in individuals screened for refractive surgery. · METHODS: Ocular HOAs and mesopic pupil size were studied in 2 458 eyes of 1 240 patients with myopia, myopic astigmatism and compound myopic astigmatism and 215 eyes of 110 patients with hyperopia, hyperopic astigmatism and compound hyperopic astigmatism using the Zywave aberrometer (Busch& Lomb). All patients had correctable refractive errors without a history of refractive surgery or underlying diseases. Root-mean-square values of HOAs, total spherical aberration, total coma and mesopic pupil size were analyzed. Ocular HOAs were measured across a ≥ 6.0 mm pupil, and pupil size measurements were performed under the mesopic condition. · RESULTS: The mean values of HOAs, total spherical aberration and total coma in the myopic group were 0.369 μm, ±0.233, 0.133±0.112μm and 0.330±0.188μm, respectively. In the hyperopic group the mean values of HOAs, total spherical aberration and total coma were 0.418μm±0.214, 0.202±0.209μm and 0.343±0.201μm, respectively. Hyperopes showed greater total HOAs (P <0.01) and total spherical aberration (P <0.01) compared to myopes. In age-matched analysis, only the amount of total spherical aberration was higher in the hyperopic group (P =0.05). Mesopic pupil size in the myopic group was larger (P ≤0.05). · CONCLUSION: The results suggested that significant levels of HOAs were found in both groups which are important for planning refractive surgeries on Iranians. There were significantly higher levels of total spherical aberration in hyperopes compared to myopes. Mesopic pupil size was larger in myopic group.
文摘Retaining walls have been used in many construction projects such as for road and inclined surfaces protection. The damage caused by an earthquake depends on the fundamental frequency, amplitude and the duration of the seismic motion. These parameters strongly depend on the seismic properties of the layers that are near the surface. In the study of retaining walls, in addition to the infl uence of soil, the infl uence of topography is also important. In the present study, site response analysis is performed by using fi nite element software PLAXIS to obtain the eff ect of various factors such as embedded length of the sheet pile, underground water table, length and angle of the nail, shear wave velocity of soil on site eff ect and dynamic response. Moreover, for better understanding of the eff ect of the above parameters, the stability analysis was performed by using shear reduction method. The results show that an increase in the embedded length of the sheet pile and the length of nailing causes an increase in the amplifi cation factor. Moreover, for shear-wave velocity in the range of 200- 600 m/s, the amplifi cation factor increases with increase of the shear-wave velocity due to the decrease of nonlinear behavior.
基金financial support received from the National Natural Science Foundation of China(81373356,81573378 and 81703436)the Science and Technology Innovation Action Plan for Basic Research of Shanghai 2014 (14JC1493200)CASIMM0120153020,Shanghai Sailing Program 2017(17YF1423500)
文摘Self-nanoemulsifying systems(SNEs) have excellent ability to improve the solubility ofpoorly water-soluble drugs(PWSD). However, SNEs are likely to be degraded in gastroin-testinal(GIT) when their surface is recognized by lipase/co-lipase enzyme complex, result-ing in rapid release and precipitation of encapsulated drugs. The precipitates are then cap-tured and removed by intestinal mucus, reducing the delivery efficacy of SNEs. Herein, theamphiphilic polymer Pluronic? F127 was incorporated into long and short-chain triglyc-erides(LCT, SCT) based SNEs to diminish the recognition and therefore minimized theirdegradation by enzymes and clearance by mucus. The SNEs were characterized in termsof particle size, zeta potential and stability. Ex vivo multiple particles tracking studies wereperformed by adding particle solution into fresh rat mucus. Cellular uptake of SNEs wereconducted by using E12 cells, the absorption and distribution in small intestine were alsostudied after oral administration in male Sprague-Dawley(SD) rats. The in vitro digestionrate of SNEs were found to be in following order SCT-SNE > SCT-F127-SNE > LCT-SNE > LCT-F127-SNE. Moreover, the LCT-F127-SNE was found to be most effective in enhancing cellularuptake, resulting in 3.5-fold, 2.1-fold and 1.7-fold higher than that of SCT-SNE, LCT-SNE andSCT-F127-SNE, respectively. After incubating the SNE with E12 cells, the LCT-F127-SNE ex-hibited the highest amount regarding both mucus penetration and cellular uptake, with anuptake amount number(via bicinchoninic acid(BCA) analysis) of 3.5-fold, 2.1-fold and 1.7-fold higher than that of SCT-SNE, LCT-SNE and SCT-F127-SNE, respectively. The in vivo results revealed that orally administered LCT-F127-SNE could significantly increase the bioavailability of Cyclosporine A(CsA), which was approximately 2.43-fold, 1.33-fold and 1.80-fold higher than that of SCT-SNE, SCT-F127-SNE and LCT-SNE, respectively. We address in this work that F127-modified SNEs have potentials to improve oral drug absorption by significan
