Search

The effect of pump impeller modification by a new approach, pump impeller shroud trimming (PIST), on the flow field and pump performance is examined both numerically and experimentally. The primary purpose of this study is to investigate the hydraulic performance of single-phase centrifugal pumps, which are refined by the PIST method, with low and medium specific speeds. In this type of shroud trimming, different trimming sizes are applied only to the shroud plate of the closed impeller, while the geometries (diameters) of the hub and blades remain unchanged. This modification, which increases the clearance between the impeller and casing from the shroud side, causes desirable conditions for pumping fluid containing undissolved gas. Computational fluid dynamics software (ANSYS-CFX) is used to predict the hydraulic performance of centrifugal pumps. Two well-known turbulence models, the renormalization group (RNG) k-ϵ developed model and shear stress transport (SST) k-ω, are used to predict the flow patterns. The computational results are verified through the comparison of experimental and unsteady numerical simulations with steady numerical data. After ensuring the accuracy of the flow-field simulation approach, further numerical analysis is performed for both pumps by changing the impeller shroud diameter. The effects of the geometric changes on the performance curves, efficiency, flow field, pressure distribution inside the pump components and the radial force acting on both pump types are investigated comprehensively. The results show that the shroud trimming reduces the produced head and efficiency at the design points. Examination of the radial force, which is applied on the rotating parts, shows that shroud-trimmed impellers experience higher radial forces than closed impellers in both pump types owing to the lack of a uniform pressure distribution around the impeller outlet. Accordingly, the relevant information obtained is used to modify the existing coefficients to predict the radial forces.

The application of nanomaterials for their antibacterial properties is the subject of many studies due to antibiotic resistance of pathogen bacteria and the necessity of omitting them from food and water resources. Graphene oxide (GO) is one of the most popular candidates for antibacterial application. However, the optimum condition for such an effect is not yet clear for practical purposes. To shed light on how GO and bacteria interaction depends on size, a wide range of GO flake sizes from hundreds of µm

Background and Objectives: On 12 November 2017, an earthquake with a magnitude of 7.3 on the Richter scale occurred in Kermanshah Province. Explaining the challenges and needs of the victims in such circumstances can be an important source of information for future planning and better management of such conditions. Thus, the purpose of this study was to explain the challenges and needs of the earthquake victims. Methods: This study was a qualitative study. Twenty-nine semi-structured interviews were conducted with managers, policymakers, and health and emergency relief providers in earthquake areas, and 10 focused group discussions were held with earthquake victims from December to February 2016. The data were analyzed using conventional content analysis. Results: The needs and challenges in Kermanshah earthquake were classified into three periods after the earthquake: 1. Challenges and needs in the first few days with three sub-categories including management, rescue services, and urgent care, 2- Challenges and needs in the first few weeks after the earthquake with three sub-categories including housing and emergency assistance, public health services, and access to health care; and 3. Needs and challenges in several months after the earthquake with four sub-categories including economic, social, infrastructural and health service needs. Conclusion: Lack of unity of command was the main challenge in this earthquake. Another point was the health needs of victim earthquakes over time. Therefore, dispatching of aid forces to the affected areas during natural disasters should be based on planning and needs.

One of the main causes worldwide is cancer. One of the important approaches to cancer treatment is the use of chemotherapy drugs but nowadays, the use of smart drugs by researchers is being used to treat cancer. The most important carrier of drug delivery to cells is the use of carbon nanotubes. In this research, the possibility of formation of interactions between carbon nanotube and Gemcitabine anticancer drug is investigated with M06/6-311G level. The results obtained by M06/6-311G level indicate adsorption of the drug into nanotubes is physical. The obtained interaction energy and obtained bonding energy values with standard method were corrected by basis set superposition error (BSSE) on the same level of theory. The binding energy in the solvent phase is lower than the gas phase. Hence, the stability of the studied reaction increases in solvent phase with regard to the gas phase. The NBO analysis shows which the transfer electron can occur from the lone pair of Nitrogen (donor atom) in the Gemcitabine to the $$ \sigma^{ * } $$ orbital of the carbon atoms (acceptor atoms) in single-walled carbon nanotube. As well as the data of the atoms in a molecule (AIM) theory showed which the N17–C61 bond is a partial covalent bond.

In this research, a 3D (three dimensional) modified in-pipe hydro Savonius turbine with a deflector is studied experimentally and numerically. The new Savonius turbine has two blades, consisting of a large number of semicircles with different diameters and its axis is perpendicular to the flow direction. The turbine and a deflector are constructed 3D printing, and then tested in a laboratory rig in several operating conditions. The same conditions as in the experiments are simulated numerically. The validity of numerical results is proved by comparison with experimental results. Hence, numerical simulation is developed to investigate the effects of deflector and turbine geometry. Moreover, a theoretical consideration to evaluate output power is provided. In this study, the deflector geometry is defined by two parameters: blockage coefficient, and angle, which with turbine aspect ratio are considered as three variable parameters. The effect of changing these three parameters on the flow rate, output torque, and turbine efficiency is determined and described graphically using 3D streamlines and pressure contours. The results indicate a positive effect of increasing turbine height. However, the increase in deflector parameters is positive only up to a certain amount and beyond it that has an adverse effect on turbine performance.

An air-core vortex can be formed wherever water drains or discharges from a container. In some cases, detached bubbles or a complete air core can develop and subsequently enter the downstream equipment causing performance loss or even damage. In the present study, a numerical study and a physical discussion are done on the water draining out of a tank in order to determine why air-core vortex generates and on which factors it depends. The same condition as in the existing experiment was simulated numerically and validated by comparing against it. Subsequently, the numerical simulations are developed to alter physical and geometrical factors, i.e., wall rotation and surface tension both for laminar and turbulent flow regimes. It is realized that the generation of the air core depends on the action of drain and not to the environmental elements such as the effect of the surrounding walls. In fact, these elements can produce or destruct the angular momentum which plays a vital role in process of air-core vortex generation. Meanwhile, the fluid particle moves toward the drain port, and its angular velocity increases that it makes a narrow zone in the water having larger axial velocity and angular velocity with a lower pressure compared to the surrounding water. This narrow zone is the key factor, and when it develops, the free surface deforms and the air core generates.

Level of utilization of clean energy has grown dramatically in recent years due to increased pollution and environmental issues. For instance, the extra potential energy in water supply system is usually wasted, due to its low capacity. Design of a proper turbine has recently been given more attention by researchers to apply this clean energy. In the present paper, a modified Savonius turbine, suitable for use in a 4-inch pipe, is designed. Turbine with two blades is tested in a laboratory rig and also simulated with the FLUENT software. By matching numerical and laboratory results, simulations are expanded and the blades number effect on turbine performance is studied under determined hydraulic conditions. The flow field around the modified Savonius turbine is interpreted by the 3D streamlines and pressure contours. The obtained results indicate that increasing the turbine blade numbers up to 5 and more causes the turbine efficiency first to rise and then to fall, respectively.

Water scarcity and environmental impacts of blowdown within steam power plants are among the important growing concerns. In order to solve these problems, applying a zero liquid discharge (ZLD) system for treating the brine of the power plants and reusing this water is crucial. In this study, the process of a ZLD system is evaluated by using energy and exergy analyses. The ZLD system was designed to recover brines to demineralize water, which consists of four main parts including vacuum evaporator, roots pump, heat exchanger, and circulation pump. The effects of the dimensional and operating parameters on the freshwater flow rate, exergy efficiency, and the consumption power are investigated. When volume of the evaporator is 7 m3, with increase in total evaporation time from 1 to 3 h, total power consumption decreased from 106.16 to 99.52 kW h and freshwater production reduced from 5914.62 to 2048.52 L h−1. The amount of produced freshwater flow rate is independent of the recirculating flow rate and is a function of the evaporator’s volume. Therefore, in volumes of 3, 5, and 7 m3, the produced freshwater flow rate is constant at about 1300, 2200, and 3070, respectively. Also, the results showed that when increasing the concentration of the brine in the range of 2000–30,000 ppm, the flow rate of the produced freshwater decreases from 3377 to 2911 L h−1 and the total power consumption reduced from 113.28 to 96.42 kW h. Moreover, by increasing the volume of vacuum evaporator, freshwater flow rate rises. Increasing the freshwater flow rate has a dramatic influence on the early working cycles. Since the evaporation is a cyclic process, the exergy efficiency of the roots pump and heat exchanger improves, while the exergy efficiency of the vacuum evaporator decreases versus increasing working cycles.

Due to limitation of energy resources, a large body of research activities has been turned to investigate potential alternative avenues to supply energy. In this regard, the renewable sources, which can provide the sustainable and cleaner energy production, have increasingly become attractive. Hydropower has the highest proportion of the renewable energy sources. Availability and high efficiency are the undeniable advantages of the hydro potentials. In this paper, hydro-energy extraction from pipelines by a new designed vertical axis turbine is studied experimentally and numerically. The turbine scheme is inspired by the Savonius rotor turbine, which includes two semicircular blades that is built by the 3D printer and installed vertically in a 100 mm transparent pipe. A sloped block is used just before the turbine blades to concentrate the flow and enhance the efficiency. In experiments, flow rate ranges from 2.7 × 10−3 m3/s to 7.3 × 10−3 m3/s and pressure drop that occurs through the turbine is less than 10.5 kPa. Numerical results show an acceptable agreement with experiments and assure that numerical method is reliable. Following successful validation, numerical studies are expanded, in order to study more details on the new turbine performance. According to the numerical results, the characteristic curves of the new turbine are depicted and described. In numerical simulation, for different turbine rotational speeds, the flow rate and the pressure difference examined are up to 12 × 10−3 m3/s and 30 kPa, respectively. Using the obtained results, investigations and studies are performed to describe turbine behavior under the effects of changing the clearance and flow field conditions. Finally, cyclic variations of turbine flow rate, torque and minimum pressure on the turbine blade are described by velocities streamlines. This approach might preform design improving for such a turbine.

The present study introduces distance based change detection (CD) algorithms in polarimetric synthetic aperture radar (PolSAR) data. PolSAR images, due to interactions between electromagnetic waves...

Water scarcity and environmental impacts of the steam power plants blow down, is one of the growing concerns. During the evaporation of water in the steam cycle of the power plant, most of the impurities of water and vapor do not evaporate and remain in the boiler. By increasing the concentration of these impurities, boiler tubes are corroded. To adjust the concentration of these impurities, some of the water in the cycle is drained, which is called blowdown. Blowdown water has a high exergy content that is going to be wasted. In this study, by recovering a great amount of contained water and heat of power plant blow down, the entering wastewater to the environment is decreased and the total power of power plant is increased. This recovery system includes Evaporator and Vacuum pump. In this system a vacuum is created in the vaccum tank by vacuum pump which causes the water to evaporate and is injected into the steam cycle. The results show that by adding the recovery system, the amount of drained wastewater from the plant to the surrounding environment decreases from 3.118 kg/s to 1.799 kg/s. After Energy and Exergy analysis, it is shown that the output power increases by 0.53%, and the exergy returns from 20.73% to 20.84%. Also, the effect of the Evaporator vacuum on the output power and the amount of recovered water indicates that with the reduction of the Evaporator vaccum pressure, the amount of the output power is reduced, but instead due to further evaporation of the water, the amount of recovered water in the Evaporator will increase. After Energy and Exergy analysis, the results are optimized by the Genetic Algorithm. The inlet temperature of HPT1, inlet pressure of HPT1, outlet pressure from each turbine, and pinch point for the first heat exchanger are considered as decision variables. Optimization results show that by obtaining suitable decisions variable amounts, output power is increased from 34.01 MW to 34.92 MW. For evaluating the results on the power plant operation, SEGS VI power plant in the US (California) is used.

The development of the boundary layer leading to separation of the flow from the surface along with the formation of the wake regions dramatically increases the overall convective heat transfer coefficient and the exerted drag force on the body. Sustainable building designs are usually encountered with energy issues mainly related to heat loss through the facades due to convective heat transfer and aerodynamic loading problems on the structure due to severe drag forces on facades. Flow control has been demonstrated as a promising tool for reducing wake intensity and preventing flow separation in different areas of aerospace and mechanical engineering. This paper numerically investigates the feasibility and efficiency of utilizing a novel idea based on locating flow controlling blades (FCBs), designed by the Department of Building Aerodynamics of the Solar Decathlon China 2013 (SDC 2013) Team of Iran, in the periphery of the external facades of the house in order to control the external flow and make it more streamlined than the real case of wind around approximately cubic shaped houses, while the objective is to reduce the convection heat loss from the walls and drag force exerted on them. As a case study, the smart sustainable house (Shāremān) was designed by the RTEOPT (Research Team for Energy Optimization and Passive-house Technologies) and participated in the SDC 2013 held by the U.S. DOE and National Energy Administration of China is presented. A 2D incompressible steady computational fluid dynamics solver, based on the finite volume method in the available commercial software package Fluent, is employed, and wind directions varying from 0 to 330 are resolved. The numerical results show an average reduction of about 15.6% for convective heat transfer coefficient over 12 different conditions; also, a decrease of about 4.8% is observed for the pressure difference between the stagnation point and the opposing corresponding point behind the body of the house.

In this research, mesoporous magnesium oxide/poly(propylene glycol) (MgO/PPG) hybrid nanofibers were synthesized as a new adsorbent for the removal of heavy metal ions from solutions. To do this, firstly, mesoporous MgO nanofibers were prepared using an electrospinning technique. Then, a polymeric layer containing PPG was deposited onto the surface of the MgO nanofibers. The aim was to produce hybrid nanofibers with a mesoporous structure, thus, the amount of the PPG containing layer was optimized. The characteristic analyses showed a high specific surface area value (185 m2 g−1) even after the deposition of the polymeric layer. Although the mean mesopore size on the nanofiber surface was decreased, the size of the pores existing among the nanofibers increased because of the increasing nanofiber diameter. The average thickness of the polymeric layer was 7 nm. An investigation of the topography of the nanofibers revealed that the average surface roughness values increased after the deposition of the polymeric layer. The effect of operational parameters including adsorbent dosage, pH and initial metal ion concentration in the adsorption process was investigated. The results showed that the maximum adsorption capacity occurs at a pH of 7.5. The isotherm and kinetics of the adsorption process were evaluated using a non-linear regression method. To determine the best fit model for each system, three error functions were used. The results showed that the experimental data followed a Langmuir isotherm. Although the intra-particle diffusion was influenced by adsorption rate, the adsorption kinetic conformed to the pseudo-second order kinetic model. The regeneration experiment of nanofibers showed that the adsorption capacity for cadmium, copper and lead was as high as 1900.05, 1919.28 and 1922.79 mg g−1 after seven cycles, respectively.

The aim of this study was to detect the association of the cytochrome P450 (CYP) 17 T-34C and CYP19 T

Monitoring and surveillance changes around the world need powerful methods, so detection, visualization, and assessment of significant changes are essential for planning and management. Incorporating polarimetric SAR images due to interactions between electromagnetic waves and target and because of the high spatial resolution almost one meter can be used to study changes in the Earth's surface. Full polarized radar images comparing to single polarized radar images use amplitude and phase information of the surface in different available polarization (HH, HV, VH, and VV). This study is based on the decomposition of full polarized airborne UAVSAR images and integration of these features with algebra method involves Image Differencing (ID) and Image Ratio (IR) algorithms with the mathematical nature and distance-based method involves Canberra (CA) and Euclidean (ED) algorithms with measuring distance between corresponding vector and similarity-based method involves Taminoto (TA) and Kulczynski (KU) algorithms with dependence corresponding vector for change detecting purposes on two real PolSAR datasets. Assessment of incorporated methods is implemented using ground truth data and different criteria for evaluating such as overall accuracy (OA), area under ROC curve (AUC) and false alarms rate (FAR). The output results show that ID, IR, and CA have superiority to detect changes comparing to other implemented algorithms. Also, numerical results show that the highest performance in two datasets has OA more than 90%. In other assessment criteria, mention algorithms have low FAR and high AUC value indices to detect changes in PolSAR images.

We are employed in the present study of single-walled carbon nanotubes (SWCNTs), carboxylate group functionalized single-walled carbon nanotubes (SWCNT-COOH), graphene (G) and graphene oxide (GO) as alternative adsorbents for the removal of cationic dye Basic Red 46 (BR 46), from aqueous solution. Various physico-chemical parameters were studied such as electrical conductivity behaviors, contact time, solution pH, and dye concentration. The experimental results show that SWCNTs, SWCNT-COOH, G and GO are promising adsorbents for removing BR 46. The adsorption equilibrium data were analyzed using various adsorption isotherms, and the results have shown that adsorption behavior of BR 46 could be described reasonably well by the Langmuir isotherm. Results showed that the removal of BR 46 increased with increasing initial dye concentration, contact time and pH. Adsorption kinetics data were modeled using the pseudo-first and pseudo-second order, and intra-particle diffusion models. Results show that the pseudo-first order kinetic model for SWCNTs, SWCNT-COOH and the pseudo-second order for G and GO were found to correlate the experimental data well.

Two proteins, i.e. bovine serum albumin and egg white lysozyme are used as model adsorbents for the food industry (dairy) wastewater and multi-walled carbon nanotubes (MWCNT) and amine functionalized multi-walled carbon nanotubes (MWCNT-NH2) surfaces were used as adsorbents. Various effective parameters such as contact time, the initial concentration of proteins, initial pH levels, and temperature were well investigated and optimized using batch adsorption study. Upon optimization, it was observed that the on increasing the initial concentration the adsorption of both the proteins also increases. The equilibrium adsorption data of Lysozyme using MWCNTs and MWCNT-NH2as adsorbents were well fitted and in good agreement with the type (II) Langmuir isotherm model and Freundlich isotherm model, respectively, while on the other hand, for serum albumin adsorption using MWCNTs and MWCNT-NH2 as adsorbents were described was well fitted and in good agreement with type (II) Langmuir isotherm model.

In this paper a nonlinear investigation is presented for impact response of functionally graded material (FGM) doubly curved panels which are resting on Winkler–Pasternak elastic foundation with simply supported end condition. The governing equations of the doubly curved panels are based on a Reddy’s higher order shear deformation theory with the von Karman-type of kinematic nonlinearity. Moreover, the effect of heat conduction is considered and material properties of panels are assumed to be temperature dependent and vary along the thickness according to Mori–Tanaka micromechanical model. In addition, by using a modified Hertz’s contact law, the influence of material properties of the substrate layers on impact response is taken into account. The equations of motion are solved via an analytical procedure and a parametric polynomial solution is extracted. The influences of materials property gradient, initial velocity of the impactor, curvatures ratio, aspect ratio and the effect of elastic foundations on impact response of panels are discussed.

In this paper, hydroxylated α-Fe 2 O 3 nanofiber was synthesized by the combination of electrospinning method and in-situ polymerization and its potential for the adsorption of cationic dyes was investigated. The vinyl acetate monomer was polymerized onto the surface of α-Fe 2 O 3 nanofiber and subsequently it was hydrolyzed in an alkaline solution to convert the acetate group to hydroxyl group. The optimized condition of polymerization was reported. The characteristics of nanofiber were investigated by Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscope (FE-SEM), energy-dispersive X-ray (EDX) and Brunauer–Emmett–Teller (BET). The FTIR result confirmed successful polymerization of vinyl acetate and generation of hydroxyl group on the surface. Microscopic analyses revealed that the modified nanofiber has a long continuous structure because of attaching the adjacent silanol group of nanofibers. Also, decreasing in the total surface area of nanofiber was detected by BET analysis. Furthermore, the influence of parameters affecting on dye removal such as adsorbent dosage, initial dye concentration and pH was investigated. The mechanism and rate of adsorption were evaluated by different adsorption isotherm and kinetic models. Non-linear regression was used to determine the best fit model for each system. To do this, three error functions were applied to predict the optimum model. It was found that the adsorption of dyes onto hydroxylated nanofiber is based on Langmuir isotherm and pseudo-second-order kinetic model.

In this paper a nonlinear investigation is presented for impact response of functionally graded material plates which are resting on a nonlinear three-parameter elastic foundation with simply supported end condition. In foundation, the influence of linear Winkler and Pasternak parameter is taken into account. The governing equations of the plate are derived based on a Reddy's higher order shear deformation theory with the von Karman-type of kinematic nonlinearity. The effect of thermal field is considered and material properties of the plates are assumed to be temperature dependent, as well and vary along the thickness according to Voigt model. In addition, by using a modified Hertz's contact law, the influence of material properties of the substrate layers on impact response is considered. The equations of motion are solved via an analytical procedure. The effects of deformation theories as well as thermal field, foundation parameters and impactor's parameters are discussed in results and discussion section.

Substantial interest exists in understanding the role of low-disturbance construction methods in mitigating industrial impacts to native grassland soils and vegetation. We assessed soil and vegetation responses to conventional high-disturbance sod-stripping and revegetation on sandy soils, and the alternative practice of low-disturbance access matting to provide a temporary work surface on sandy and loamy soils. Treatments were associated with high-voltage transmission tower construction during 2014 within the Mixedgrass Prairie. High-disturbance sites were hydroseeded in May of 2015, while low-disturbance sites recovered naturally. We assessed soil physical (bulk density, water infiltration) and chemical properties (organic matter, pH, and electrical conductivity) after construction and herbage biomass for three growing seasons. Sod-stripping led to 53% greater soil bulk density and 51% less organic matter than nondisturbed controls, while water infiltration increased by 32% in these high-sand (>80%) soils. In contrast, access matting led to minimal soil property changes regardless of the texture. While total herbage biomass was unaffected by all construction treatments, sod-stripping reduced grass biomass by 80% during the first growing season, which coincided with a 119% increase in forb mass. Root biomass (0–15 cm) also declined 77% with sod-stripping. Vegetation biomass on sites with access matting remained largely unaffected by the disturbance. Overall, low-disturbance construction methods using access matting were more effective than sod-stripping in mitigating the negative impacts of industrial development on Mixedgrass soil properties, as well as vegetation biomass, and are recommended as a best management practice during industrial disturbance.

Hydropower systems can provide a considerable proportion of sustainable and clean energy. In the present study, the performance of a drag-based vertical axis in-pipe turbine is optimized to harvest the existing excessive potential energy from small diameter (100 mm) pipelines more effectively. The enhancement of the efficiency and output power of the turbine in this research makes it as a more promising and sustainable device for distributed power generation. To achieve a comprehensive solution all the factors affecting in-turbine performance has been taken into account simultaneously. Due to the complicated relation between turbine design parameters and its performance, artificial neural networks (ANN), which is a popular tool for modeling devices, has been deployed to generate a predictor model for turbine performance. The predictor model is formed on a dataset provided by 3D transient numerical simulations, which are validated by previous experiments. The optimization analysis is based on the in-pipe turbine non-dimensional variables, which are introduced to provide more simplification. For the particular water head loss less than 5 m and the flow rate bounded to the typical range, the proposed in-pipe turbine produces a power of 200 W with an efficiency over 33%, which shows a considerable improvement compared to the previously developed drag-based in-pipe turbines.

In this research, the superposition of shifted Laguerre–Gaussian (LG) beams and their intensity distribution are studied in cylindrical coordinates. By complex transverse shifting of conventional LG beams, the symmetry of intensity structure is lost and deformed to the crescent. Increasing the amount of beam pure imaginary shift causes the beam is focused on a smaller crescent. The obtained results from applying changes on the real transverse shift, topological charge, and radial index parameters of superposed LG beams depict the possibility of these beams to apply in optical trapping. As the radial index increases, in addition to the radial variation of the intensity distribution, the position and shape of the crescents are changed. Besides, analytical formulate for the angular spectrum of the superposed beams is derived and the relation of their orbital angular momentum (OAM) obtained. It is observed, by increasing the OAM, the radius of intensity distribution is increased. By the combination of these difference adjustable parameters, the localized intensity distribution has been prepared, which could be used for the production of controllable optical traps. The obtained experimental results confirm the simulation results.

The remaining torque of disengaged wet clutches is a major source of energy loss and, therefore, an objective of current research. The present contribution describes the necessary simplifications to obtain an analytical solution of the governing equations by means of an order-of-magnitude analysis. The obtained results are brought to a dimensionless frame of reference, where formerly unknown simple dependencies of the drag torque and the aeration onset have been uncovered. The dimensionless description serves as promising a means to achieve a quantitative comparison of experimental data. Additionally, a new modelling concept for grooves is introduced, which is based on the hydraulic-diameter concept. The combination of either approach offers a robust prediction method for drag torque and aeration onset.

Autologous platelet-rich plasma (PRP) is gaining increasing use as a wound healing promoter in a variety of clinical settings, including dentistry. Fresh PRP is often used, necessitating daily draws. The present study investigates the possibility of using stored PRP without having to freeze it by storing PRP under variable conditions and assessing growth factor release as a surrogate marker of continued viability.Freshly drawn PRP was stored in oxygen permeable and non-oxygen permeable containers under conditions of constant agitation with or without added prostaglandin, intermittent agitation and no agitation, over an 8-day period. Serial platelet counts, mean platelet volume, platelet distribution width and platelet-large cell ratio, and collagen-induced aggregometry were undertaken. Once collagen-induced aggregation had gone to completion, the plasma was centrifuged to pellet platelet material and the supernatants separated and frozen for batched analysis of released platelet-derived growth factor-BB (PDGF-BB).As would be anticipated, platelet counts, percentage aggregation and PDGF-BB levels all reduced over time. Platelet parameters suggested that platelets were more stable in the non-oxygen permeable containers, possibly due to pH drift and a degree of microaggregate formation in the oxygen permeable containers.Although platelet integrity and PDGF-BB fell over time, the intermittently agitated non-oxygen permeable container appeared to retain better platelet integrity and function, and PDGF-BB release, than other storage conditions, with potential for clinical use for 5-8 days.

Fire affects the physical and chemical properties and soil biological activity of natural ecosystems. This study was conducted in the Miyan Tang region, Ilam Province in western Iran. The study site was 110 hectares, where we sampled soils in areas that were classified by fire severity: low (LS), high (HS) and medium severity (MS), and unburned (UB), which served as the control. In each severity class, 25 transect points were randomly selected for measurement. Around each transect plot center, 3 soil samples were selected randomly and soils collected from the 0 to 20 cm depth were combined into a composite sample that was used in laboratory analysis to represent conditions at that point. Plots in the UB and LS fire classes had similar soil conditions and had higher values of factors such as saturated moisture, organic carbon, carbon dioxide, and silt and clay content. In contrast, plots in the HS and MS fire severity classes were clustered in the positive direction along the first axis that represented gradients in soil acidity, electrical conductivity, cation exchange capacity, accessible phosphorus, accessible potassium, bulk density, and sand. Soil attributes were similar in areas of HS and MS fire severity classes, whereas soil conditions in the LS class and UB controls were most similar. Fire in the LS areas either did not significantly alter the physical–chemical soil properties and microbial basal respiration, or soils were able to recover quickly after being burned.

A numerical simulation of the particle-gas flow in a vertical turbulent pipe flow was conducted. The main objective of the present article is to investigate the effects of dispersed phase (particles) on continuous phase (gas). In so doing, two general forms of Eulerian-Lagrangian approaches namely, one-way (when the fluid flow is not affected by the presence of the particles) and two-way (when the particles exert a feedback force on the fluid) couplings were used to describe the equations of motion of the two-phase flow. Gas-phase velocities which are within the order of magnitude as that of particles, volume fraction, and particle Stokes number were calculated and the results were subsequently compared with the available experimental data. The simulated results show that when the particles are added, the fluid velocity is attenuated. With an increase in particle volume fraction, particle mass loading and Stokes number, velocity attenuation also increases. Moreover, the results indicate that an increase in particle Stokes number reduces the special limited particle volume fraction, according to which one-way coupling method yields plausible results. The results have also indicated that the significance of particle fluid interaction is not merely a function of volume fraction and particle Stokes number.

Fe3O4 nanoparticles were synthesized via coprecipitation method and their dispersion properties were investigated using three types of anionic poly (ethylene glycol)-graft-acrylic comb dispersants (APADs). The Fe3O4 nanoparticles have been characterized with powder X-ray diffraction, transmission electron microscopy, and dynamic laser scattering while the prepared APAD has been studied by Fourier transmission infrared and nuclear magnetic resonance spectroscopy techniques. The results revealed that Fe3O4 nanoparticles could be well dispersed using APAD that PEG 2000 was grafting to the backbone of dispersant. It was also found that temperature of synthesis procedure affects a dispersion of nanoparticles more significantly than mixing time and APADs molecular weight.

Rapid adsorption process of hazardous malachite green (MG) dye from the liquid phase onto the developed adsorbent i.e. graphene oxide (GO) and reduced graphene oxide (rGO) surfaces was well studied and elucidated. The batch adsorption experiments were carried out in order to evaluate the optimized values of the influential parameters such as initial pH, contact time, and temperature. The obtained optimized values of pH, contact time and temperature was 3, 100 min and endothermic nature of the adsorption process. It was found that by increasing the pH value from 3 to 9, the removal of malachite green dye by the developed adsorbent i.e. GO and rGO was decreased. Additionally by increasing the temperature, the removal of noxious MG dye by GO and rGO adsorbents was increased, which directly indicates towards the endothermic nature of the adsorption process. The adsorption kinetic data of malachite green dye on GO and rGO surfaces was found to be well fitted and in good agreement with the pseudo-first-order kinetic model because of the low value of the chi-square statistic (χ2) and high value of the correlation coefficients (R2).

MWCNTs functionalized with the carboxylate group are used as efficient adsorbent for the rapid removal and fast adsorption of malachite green from the aqueous solutions. The optimized contact time and pH were 10 min and 9, respectively. The effect of temperature revealed that the adsorption capacity of malachite green (MG) dye increased with increasing contact time, temperature and pH of the working solution. The adsorption equilibrium and kinetic data was well fitted and found to be in good agreement with the Langmuir isotherm model and pseudo second order kinetic model respectively with high correlation coefficient.

This research is about an energy harvesting in-pipe system that generates electricity from excess pressure of the water flow in gravity-fed pipelines. These systems consist of multiple spherical lift-based turbines. The turbine configuration was modeled and fully parameterized to some design factors that can be changed in a code-based design. The physical concepts of the turbine were thoroughly analyzed to obtain a profound perception of the effect of each geometric parameter on the turbine performance. The performance improvement was investigated based on three metrics, namely the power coefficient, the probability of cavitation, and the pressure coefficient using a numerical analysis validated with some performed experiments. This validation indicates that the chosen numerical approach is reasonably reliable for turbine performance prediction with errors of less than 8%, approximately. The optimizable geometric model of the turbine, the highly accurate numerical method, and the analytical investigation developed in this study make available essential data for related studies.

Today, graphene and graphene derivatives such as graphene oxide are widely used in chemical processes such as adsorption. Also graphene oxide-based materials (GOBMs), which are hydrophilic and biocompatible, have wide potential applications in biotechnology and biomedical engineering. We in this chapter begin with a discussion of the structures of graphene and preparation of graphene, which includes some of the graphene to provide methods and then we will explain some applications of graphene such as hydrogen storage in Al subtitutionally doped graphene, wafer-scale graphene-on-Si transistors, graphene for nanoelectronics, large-scale transfer of graphene, and chemical vapor deposition graphene for macroelectronics: transparent conductive films. The devices and methods of synthesis of graphene were investigated. As part of graphene and graphene oxide as adsorbent, we investigated adsorption process at some research that they removed dyes and metals by graphene and graphene derivatives. We introduced some of the isotherm and kinetic models and thermodynamics of the adsorption process.

Adsorption capacity of Ni2 + on graphene oxide (GO) and glycine functionalized graphene oxide (GO-G) surfaces was well investigated and elucidated. Amino group was used to functionalizing agent for the surface modification of GO to GO-G. The effect of numerous influential parameters such as contact time, temperature and initial concentration of Ni2 + in the aqueous solution was well illustrated and optimized using batch adsorption study. The optimized values of adsorbent dose, initial concentration of Ni2 +, contact time, and pH were found to be 20 mg, 15 mg/L, 50 min, and 6 respectively, ongoing through the impact of temperature it was seen that, when the temperature was increased from 283 to 308 K, the removal of Ni2 + by GO surface decreased but the removal of Ni2 + by functionalized GO-G surface decreased until 298 K and after that it was increased. Adsorption isotherm study for the adsorption process was carried out using four types of the Langmuir and Freundlich isotherm models. Results clearly depict that adsorption of Ni2 + ions on to the GO adsorbent surface was well fitted and found to be in good agreement with the type (II) Langmuir isotherm model as the obtained regression constant value (R2) is found to be 0.999 while the adsorption of Ni2 + on GO-G surface was found to be in good agreement with the Freundlich isotherm model because the regression constant value (R2) is found to be 0.999.