Chronic effects of stretching on range of motion with consideration of potential moderating variables:A systematic review with meta-analysis

Background:It is well known that stretch training can induce prolonged increases in joint range of motion(ROM).However,to date more information is needed regarding which training variables might have greater influence on improvements in flexibility.Thus,the purpose of this metaanalysis was to investigate the effects of stretch training on ROM in healthy participants by considering potential moderating variables,such as stretching technique,intensity,duration,frequency,and muscles stretched,as well as sex-specific,age-specific,and/or trained state-specific adaptations to stretch training.Methods:We searched through PubMed,Scopus,Web of Science,and SportDiscus to find eligible studies and,finally,assessed the results from 77 studies and 186 effect sizes by applying a random-effect meta-analysis.Moreover,by applying a mixed-effect model,we performed the respective subgroup analyses.To find potential relationships between stretch duration or age and effect sizes,we performed a meta-regression.Results:We found a significant overall effect,indicating that stretch training can increase ROM with a moderate effect compared to the controls(effect size=-1.002;Z=-12.074;95%confidence interval:-1.165 to-0.840;p<0.001;I^(2)=74.97).Subgroup analysis showed a significant difference between the stretching techniques(p=0.01)indicating that proprioceptive neuromuscular facilitation and static stretching produced greater ROM than did ballistic/dynamic stretching.Moreover,there was a significant effect between the sexes(p=0.04),indicating that females showed higher gains in ROM compared to males.However,further moderating analysis showed no significant relation or difference.Conclusion:When the goal is to maximize ROM in the long term,proprioceptive neuromuscular facilitation or static stretching,rather than ballistic/dynamic stretching,should be applied.Something to consider in future research as well as sports practice is that neither volume,intensity,nor frequency of stretching were found to play a significant role in ROM yields.

Kinematic analysis of flexible bipedal robotic systems

In spite of its intrinsic complexities,the passive gait of bipedal robots on a sloping ramp is a subject of interest for numerous researchers.What distinguishes the present research from similar works is the consideration of flexibility in the constituent links of this type of robotic systems.This is not a far-fetched assumption because in the transient(impact)phase,due to the impulsive forces which are applied to the system,the likelihood of exciting the vibration modes increases considerably.Moreover,the human leg bones that are involved in walking are supported by viscoelastic muscles and ligaments.Therefore,for achieving more exact results,it is essential to model the robot links with viscoelastic properties.To this end,the Gibbs-Appell formulation and Newton's kinematic impact law are used to derive the most general form of the system's dynamic equations in the swing and transient phases of motion.The most important issue in the passive walking motion of bipedal robots is the determination of the initial robot configuration with which the system could accomplish a periodic and stable gait solely under the effect of gravitational force.The extremely unstable nature of the system studied in this paper and the vibrations caused by the impulsive forces induced by the impact of robot feet with the inclined surface are some of the very serious challenges encountered for achieving the above-mentioned goal.To overcome such challenges,an innovative method that uses a combination of the linearized equations of motion in the swing phase and the algebraic motion equations in the transition phase is presented in this paper to obtain an eigenvalue problem.By solving this problem,the suitable initial conditions that are necessary for the passive gait of this bipedal robot on a sloping surface are determined.The effects of the characteristic parameters of elastic links including the modulus of elasticity and the Kelvin-Voigt coefficient on the walking stability of this type of robotic systems are also studied.The findings of this parametric study reveal that the increase in the Kelvin-Voigt coefficient enhances the stability of the robotic system,while the increase in the modulus of elasticity has an opposite effect.

Spatial analysis of animal bites in Iran(2015-2020):A cross-sectional study

Objective:To investigate the distribution pattern of animal bites in Mirjaveh,Iran from 2015 to 2020.Methods:The data on animal bites were collected from the Department of Infectious Diseases,the provincial health center.Monthly climatic data on precipitation and temperature during the study period were also collected.The correlation between incidence and temperature,precipitation rate,land type,and altitude was also analyzed.Results:The results showed that men were more affected by animal bites than women(76.4%,P<0.001),and the highest incidence rate occurred in the age group of 5-19 years.The incidence rate of animal bites was found to be correlated with temperature and altitude.An increase in temperature was associated with a rise in the incidence rate of animal bites.The number of animal bites increased until 2019,possibly due to an increase in the number of dogs in the area.Conclusions:Targeted interventions should be implemented to reduce the incidence of animal bites,particularly among children,housewives,and students.Improving access to appropriate treatments,increasing public awareness of the hazards of animal bites,and increasing the number of vaccinated dogs in the area are essential strategies to be considered.

BSN:Photometric Light Curve Analysis of Two Contact Binary Systems LS Del and V997 Cyg

The light curve analyses and orbital period variations for two contact binary stars,LS Del and V997 Cyg,are presented in this work which was conducted in the frame of the Binary Systems of South and North project Ground-based photometric observations were performed at two observatories in France.We used the Transiting Exoplanet Survey Satellite(TESS)data for extracting times of minima and light curve analysis of the targe systems.The O-C diagram for both systems displays a parabolic trend.LS Del and V997 Cyg’s orbital periods are increasing at rates of dP/dt=7.20×10^(-08)days yr^(-1)and dP/dt=2.54×10^(-08)days yr^(-1),respectively Therefore,it can be concluded that mass is being transferred from the less massive star to the more massive component with a rate of dM/dt=-1.96×10^(-7)M_(⊙)yr^(-1)for the LS Del system,and dM/dt=-3.83×10^(-7)M_(⊙)yr-1for V997 Cyg.The parameters of a third possible object in the system are also considered.The PHysics Of Eclipsing BinariEs Python code was used to analyze the light curves.The light curve solutions needed a cold starspot due to the asymmetry in the LS Del system’s light curve maxima.The mass ratio fill-out factor,and star temperature all indicate that both systems are contact binary types in this investigation.Two methods were applied to estimate the absolute parameters of the systems:one method relied on the parallax of Gaia DR3,and the other used a P-M relationship.The positions of the systems are also depicted on the M-L,M-R q-L_(ratio),and logM_(tot)-logJ_(0)diagrams.We recommend that further observations and investigations be done on the existence of a fourth body in this system.

Mechanical properties and microstructural evolution of rheocast A356 semi-solid slurry prepared by annular electromagnetic stirring

Nowadays,having an effective technique in preparing semi-solid slurries for rheocasting process seems to be an essential requirement.In this study,semi-solid slurry of A356 aluminum alloy was prepared by three-phase annular electromagnetic stirring(A-EMS)technique under different conditions.The effects of stirring current,pouring temperature and stirring time on microstructural evolution,mean particle size,shape factor and solid fraction were investigated.The rheocasting process was carried out by using a drop weight setup and to inject the prepared semi-solid slurry in optimal conditions into the step-die cavity.The filling behavior and mechanical properties of parts were studied.Microstructural evolution showed that the best semi-solid slurry which had fine spherical particles with the average size of~27μm and a shape factor of~0.8 was achieved at the stirring current of 70 A,melt pouring temperature of 670℃,and stirring time of 30 s.Under these conditions,the step-die cavity was completely filled at die preheating temperature of 470℃.The hardness increases by decreasing step thickness as well as die preheating temperature.Moreover,the tensile properties are improved at lower die preheating temperatures.The fracture surface,which consists of a complex topography,indicates a typical ductile fracture.

Tectonic paleostress field and its impact on the geodynamic evolution of Central Iran, case study: the Shotori Mountain

The Shotori mountain range is located along the northern terminus of the Nayband fault on the eastern and western domains of the Tabas and Lut blocks,respectively.This range with NNW-SSE trending and approximately 120 km long includes a series of thrust faults approaching the right-lateral strike-slip Nayband fault.Since the Shotori range has experienced various geological events since the Triassic,our investigations suggest that the basement of the Central Iranian subcontinent of the Shotori range contains the early Triassic deep sedimentary with normal faults which confirms Triassic tensional tectonic stress regime in the region.After the middle Triassic,the mountain range has experienced thrust and strike-slip regimes.Therefore,in this study,we reconstruct the stress regimes for different geological periods using fault-slip data.The inversion of faultslip data reveals drastic temporal changes in the maximum stress regime(σ1)over the Triassic,Jurassic,Cretaceous,Paleogene,Neogen,and Quaternary.The reconstruction of the stress field based on the age and direction of fault movement reveals that the direction of the maximum horizontal stress axis(σ1)under a tensional stress regime was approximately N129°in the Early Triassic.This stress regime is the cause of thinning and subsidence of the Shotori sedimentary basin.During the middle Triassic,theσ1 direction was about N81°and the upper Triassic,theσ1 direction was almost N115°.The middle Triassic and upper Triassic stress states exhibited two distinct strike-slip and compressive stress regimes.This stress regime led to the uplift of the Shotori sedimentary basin.During the Jurassic,the direction of the maximum horizontal stress axis(σ1)was~NW-SE under a compressive stress regime.During the Triassic,theσ1 direction was~N-S.This stress regime led to the formation of the high topography of the Shotori Mountain Range.In the Late Cretaceous,the direction of the maximum horizontal stress axis(σ1)under the extensional stress regime was~NE-SW.This stress regime led to the uplift of the Paleogen Dacite in eastern Iran.During the Neogene,theσ1 direction was~N60°.The Quaternary tectonic regime is strike-slip and theσ1 direction is~N50°,consistent with the current convergence direction of the Arabia–Eurasia plates.Our paleostress analysis reveals four recognized stress in this area,which includes compressional,transtensional,transpressional,and strike-slip regimes.Our findings indicated that the crustal diversity of the tectonic regimes was responsible for the formation of various geological structures,such as folds,faults by different mechanisms,and the present-day configuration of the Shotori sedimentary basin.

氯离子存在条件下嗜热酸性生物浸出硫化铜精矿

本文研究了在生物浸出Midouk Shahrr-e-Babak铜矿复合体系中,氯离子对用极端嗜热菌Sulfolobus acidocalarius生物浸出硫化铜精矿的影响。细菌在pH=1.5时逐渐适应氯离子,说明溶液中氯离子的存在只是降低了细菌的繁殖和生长速度,但并没有阻止细菌的生长。当pH从2.0降低到1.5时,在前几天铜的浸出率逐步提高,9 d后铜的浸出率接近100%。随着溶液中固体含量从1%增加到3%,铜浸出时间延长了6 d。在pH=1.5、固体含量为1%、Na Cl浓度为0.5 mol/L和1.0 mol/L的条件下,9 d后的浸出率分别为98%和80%;21 d后,浸出率分别达到近100%和90%。在无微生物但其他条件相同的情况下,铜的浸出率仅为62%。

Light Curve Analysis of the AP Dor Binary System using Ground-based and TESS Observations

The short-period eclipsing binary AP Dor’s first in-depth and multiband photometric solutions are presented.We made use of our eight nights of ground-based opportunity at a southern hemisphere observatory,and twelve sectors of TESS observations.We extracted eight and 1322 minima from our observations and TESS,respectively.We suggest a new linear ephemeris based on the trend of orbital period variations using the Markov chain Monte Carlo(MCMC)approach.The PHysics Of Eclipsing BinariEs(PHOEBE)Python code and the MCMC approach were utilized for the light curve analysis.This system did not require a starspot for the light curve solutions.We calculated the absolute parameters of the system by applying the Gaia DR3 parallax method.The orbital angular momentum(J_(0))of AP Dor indicates that this system is located in a region corresponding to contact binaries.According to our results,this system is an overcontact binary system with a mass ratio of 0.584,a fillout factor of 48%,and an inclination of 53°.The positions of component stars in the AP Dor system on the Hertzsprung–Russell diagram are found.

CFD simulation of an industrial hydrocyclone with Eulerian-Eulerian approach: A case study

In the present study, a three-dimensional computational fluid dynamics simulation together with experimental field measurements was applied to optimize the performance of an industrial hydrocyclone at Sarcheshmeh copper complex. In the simulation, the Eulerian–Eulerian approach was used for solid and liquid phases, the latter being water. In this approach, nine continuous phases were considered for the solid particles with different sizes and one continuous phase for water. The continuity and momentum equations with inclusion of buoyancy and drag forces were solved by the finite volume method. The k–e RNG turbulence model was used for modeling of turbulency. There was a good agreement between the simulation results and the experimental data. After validation of the model accuracy, the effect of inlet solid percentage, pulp inlet velocity, rod inserting in the middle of the hydrocyclone and apex diameter on hydrocyclone performance was investigated. The results showed that by decreasing the inlet solid percentage and increasing the pulp inlet velocity, the efficiency of hydrocyclone increased. Decreasing the apex diameter caused an increase in the hydrocyclone efficiency.

Prediction of rock mass rating using fuzzy logic and multi-variable RMR regression model

Rock mass rating system(RMR) is based on the six parameters which was defined by Bieniawski(1989)[1]. Experts frequently relate joint and discontinuities and ground water conditions in linguistic terms with rough calculation. As a result, there is a sharp transition between two modules which create doubts.So, in this paper the proposed weights technique was applied for linguistic criteria. Then by using the fuzzy inference system and the multi-variable regression analysis, the accurate RMR is predicted. Before the performing of regression analysis, sensitivity analysis was applied for each of Bieniawski parameters.In this process, the best function was selected among linear, logarithmic, exponential and inverse functions and finally it was applied in the regression analysis for construction of a predictive equation. From the constructed regression equation the relative importance of the input parameters can also be observed. It should be noted that joint condition was identified as the most important effective parameter upon RMR. Finally, fuzzy and regression models were validated with the test datasets and it was found that the fuzzy model predicts more accurately RMR than regression models.

Simulation of a semi-industrial pilot plant thickener using CFD approach

Thickeners are important units for water recovery in various industries. In this study, a semi-industrial pilot plant thickener similar to the tailing thickener of the Sarcheshmeh Copper Mine was simulated by CFD modeling. The population balance was used to describe the particle aggregation and breakup. In this population balance, 15 particle sizes categories were considered. The Eulerian-Eulerian approach with standard k-e turbulence model was applied to describe two phases of slurry flow in the thickener under steady-state condition. The simulation results have been compared with the experimental measurements to validate the accuracy of the CFD modeling. After checking the numerical results, the effect of important parameters such as, feed flow rate, solid percentage in the feed, and solid particle size on the thickener performance was studied. The thickener residence time distribution were obtained by the modeling and also compared with the experimental data. Finally, the effects of feedwell feeding on the average diameter of aggregate and turbulent intensity were evaluated.

Simultaneous investigation of blast induced ground vibration and airblast effects on safety level of structures and human in surface blasting

The significance of studying, monitoring and predicting blast induced vibration and noise level in mining and civil activities is justified in the capability of imposing damages, sense of uncertainty due to negative psychological impacts on involved personnel and also judicial complaints of local inhabitants in the nearby area. This paper presents achieved results during an investigation carried out at Sungun Copper Mine, Iran. Besides, the research also studied the significance of blast induced ground vibration and airblast on safety aspects of nearby structures, potential risks, frequency analysis, and human response.According to the United States Bureau of Mines(USBM) standard, the attenuation equations were developed using field records. A general frequency analysis and risk evaluation revealed that: 94% of generated frequencies are less than 14 Hz which is within the natural frequency of structures that increases risk of damage. At the end, studies of human response showed destructive effects of the phenomena by ranging between 2.54 and 25.40 mm/s for ground vibrations and by the average value of 110 dB for noise levels which could increase sense of uncertainty among involved employees.

Assessment of pH-responsive nanoparticles performance on laboratory column flotation cell applying a real ore feed

Nanoparticles(NPs)can promote the column flotation process in mining industry.Nanoparticles'effects on column flotation process(copper recovery,grade and flotation rate constant)are assessed in Sarcheshmeh Copper Complex,Iran,through response surface methodology(RSM)optimization technique.The c-Al2O3,a-Fe2O3,SiO2,and TiO2 nanoparticles are selected for these experiments.A flotation rate constant is chosen as a response to assess the effect of nanoparticles on flotation in its kinetic sense.The process p H and nanoparticle dosage are selected as the influential parameters.Results obtained from RSM indicated that the maximum percentage of Cu recovery and grade is obtained at p H of 12 and nanoparticle dosage of 6 kg/t,through a-Fe2O3 and c-Al2O3 nanoparticles,respectively.Applying nanoparticles in particular c-Al2O3 and a-Fe2O3 increases the Cu recovery by 8–10%together with the grade by 3–6%in a significant manner.It is revealed that nanoparticles could effectively be applied in enhancing the flotation performance.

Prediction of face advance rate and determination of the operation efficiency in retreat longwall mining panel using rock engineering system

A new approach for prediction of face advance rete (FAR) prior to mining operation and determination of the operation efficiency after mining operation in retreat longwall mining panel is presented based upon the concepts of rock engineering system (RES). For this purpose, six longwall panels considered in Parvadeh-I coal mine. Seven major effective parameters on FAR was selected including coal mine roof rating, gas propagation, safety factor of longwall face, ratio of joint spacing to cutting depth at longwall face, longwall face inclination, panel width, floor rock mass rating. To performance evaluation of the presented model, the relationship between the average vulnerability indexes of advance operation with FAR was determined in considered panels with coefficient of determination (R2) equal to 0.884 that indicate relatively acceptable correlation and compatibility. Investigations of the research indicated that it is possible to determine the actual operation efficiency under fair conditions by a RES-based model. The inevitable reduction of FAR for each longwall panel was determined by presented model that the difference amount between the maximum possible practical face advance rate (FARmpp) and recorded actual face advance rate (FARa) indicate the operation efficiency. Applied approach in this paper can be used to prediction of FAR in retreat longwall mining panel for same conditions that can have many benefits, including better and more accurate planning for the sales market and mine operation. Also, presented method in this paper can be applied as a useful tool to determination of actual operation efficiency for other sections and extraction methods in coal mines.

Ag recovery from copper anode slime by acid leaching at atmospheric pressure to synthesize silver nanoparticles

In this paper, recovery of silver from anode slime of Sarcheshmeh copper complex in Iran and subsequent synthesis of silver nanoparticles from leaching solution is investigated. Sarcheshmeh anode slime is mainly consisted of Cu, Ag, Pb and Se. Amount of Ag in the considered anode slime was 5.4%(by weight).The goal was to recover as much as possible Ag from anode slime at atmospheric pressure to synthesize Ag nanoparticles. Therefore, acid leaching was used for this purpose. The anode slime was leached with sulfuric and nitric acid from room to 90 °C at different acid concentrations and the run which yielded the most recovery of Ag was selected for Ag nanoparticles synthesis. At this condition, Cu, Pb and Se are leached as well as Ag. To separate Ag from leach solution HCl was added and silver was precipitated as AgCl which were then dissolved by ammonia solution. The Ag nanoparticles are synthesized from this solution by chemical reduction method by aid of sodium borohydride in the presence of PVP and PEG as stabilizers. The synthesized Ag nanoparticles showed a peak of 394 nm in UV–vis spectrum and TEM images showed a rather uniform Ag nanoparticles of 12 nm.

Modeling industrial thickener using computational fluid dynamics(CFD),a case study:Tailing thickener in the Sarcheshmeh copper mine

Separation of particles from liquid in the large gravitational tanks is widely used in mining and industrial wastewater treatment process.Thickener is key unit in the operational processes of hydrometallurgy and is used to separate solid from liquid.In this study,population balance models were combined with computational fluid dynamics(CFD)for modeling the tailing thickener.Parameters such as feed flow rate,flocculant dosage,inlet solid percent and feedwell were investigated.CFD was used to simulate the industrial tailing thickener with settled bed of 120 m diameter which is located in the Sarcheshmeh copper mine.Important factor of drag force that defines the rake torque of rotating paddles on the bed was also determined.Two phases turbulence model of Eulerian/Eulerian in accordance with turbulence model ofκ-ε.was used in the steady-state.Also population balance model consists of 15 groups of particle sizes with Luo and Lehr kernel was used for aggregation/breakage kernel.The simulation results showed good agreement with the operational data.

Synthesis of clay-supported nanoscale zero-valent iron using green tea extract for the removal of phosphorus from aqueous solutions

This study addresses the synthesis of nanoscale zero-valent iron(n ZVI) in the presence of natural bentonite(B-n ZVI) using green tea extract. The natural bentonite and B-n ZVI were then applied for the removal of phosphorus from aqueous solutions at various concentrations, p H levels and contact time. The desorption of phosphorus(P) from adsorbents was done immediately after sorption at the maximum initial concentration using the successive dilution method. The characterization of FTIR, SEM, and XRD indicated that n ZVI was successfully loaded to the surface of natural bentonite. The sorption of phosphorus on B-n ZVI was observed to be p H-dependent, with maximum phosphorus removal occurring at the p H range of 2 to 5. The results demonstrate that the maximum sorption capacities of natural bentonite and B-n ZVI were 4.61 and 27.63 mg·g^(-1), respectively.Langmuir, Freundlich, and Redlich–Peterson models properly described the sorption isotherm data. For either adsorbent, desorption isotherms did not coincide with their corresponding sorption isotherms, suggesting the occurrence of irreversibility and hysteresis. The average percentages of retained phosphorus released from natural bentonite and B-n ZVI were 80% and 9%, respectively. The results indicated that sorption kinetics was best described by the pseudo-second-order model. The present study suggests that B-n ZVI could be used as a suitable adsorbent for the removal of phosphorus from aqueous solutions.

Sensitivity analysis of influencing parameters in cavern stability

In order to analyze the stability of the underground rock structures,knowing the sensitivity of geomechanical parameters is important.To investigate the priority of these geomechanical properties in the stability of cavern,a sensitivity analysis has been performed on a single cavern in various rock mass qualities according to RMR using Phase 2.The stability of cavern has been studied by investigating the side wall deformation.Results showed that most sensitive properties are coefficient of lateral stress and modulus of deformation.Also parameters of Hoek-Brown criterion and r c have no sensitivity when cavern is in a perfect elastic state.But in an elasto-plastic state,parameters of Hoek-Brown criterion and r c affect the deformability;such effect becomes more remarkable with increasing plastic area.Other parameters have different sensitivities concerning rock mass quality(RMR).Results have been used to propose the best set of parameters for study on prediction of sidewall displacement.

Application of numerical modeling and genetic programming to estimate rock mass modulus of deformation

Estimation of the rock mass modulus of deformation(Em)is one of the most important design parameters in designing many structures in and on rock.This parameter can be obtained by in situ tests,empirical relations between deformation modulus and rock mass classifcation,and estimating from laboratory tests results.In this paper,a back analysis calculation is performed to present an equation for estimation of the rock mass modulus of deformation using genetic programming(GP)and numerical modeling.A database of 40,960 datasets,including vertical stress(rz),horizontal to vertical stresses ratio(k),Poisson’s ratio(m),radius of circular tunnel(r)and wall displacement of circular tunnel on the horizontal diameter(d)for input parameters and modulus of deformation for output,was established.The selected parameters are easy to determine and rock mass modulus of deformation can be obtained from instrumentation data of any size circular galleries.The resulting RMSE of 0.86 and correlation coeffcient of97%of the proposed equation demonstrated the capability of the computer program(CP)generated by GP.

Correlation of Shear Viscosity of Nanofluids Using the Local Composition Theory

In this study,a new method is presented to correlate the shear viscosity of nanofluids by local composition theory.The Eyring theory and nonrandom two-liquid(NRTL)equation are used for this purpose.The effects of temperature and particle volume concentration on the viscosity are investigated.The adjustable parameters of NRTL equation are obtained by fitting with experimental data.The calculated shear viscosities for nanofluids of CuO/water with 29 nm particle size,Al2O3/water with two different particle diameters,36 nm and 47 nm,and CuO/(ethylene glycol,water)are compared with experimental data and the average absolute deviation(AAD)is 1.2%,while the results from some conventional models yield an AAD of 190%.The results of this study are in excellent agreement with experimental data.