Cupping therapy has been widely used for clinical treatment of soft tissue lesions. The current study investigated the effects of cupping therapy on biomechanical properties of the skin in Wistar rats. 20 rats were di...Cupping therapy has been widely used for clinical treatment of soft tissue lesions. The current study investigated the effects of cupping therapy on biomechanical properties of the skin in Wistar rats. 20 rats were divided into two groups: 10 in experimental and 10 in control group. Either the right or the left lower quadrants of the lumbar regions in the experimental group underwent 10 minutes daily cupping therapy for 12 days. The skin stiffness and ultimate tensile strength of all the rats were measured using tensiometer. The skin stiffness and ultimate tensile strength were decreased significantly in cupping side of the experimental group as compared with the non-cupping side and the control group. There were no significant differences between the non-cupping side of the experimental group and the control group. In conclusion, cupping therapy can be useful as a treatment method to reduce the skin stiffness and ultimate tensile strength.展开更多
A total of 19%of generation capacity in California is offered by PV units and over some months,more than 10%of this energy is curtailed.In this research,a novel approach to reducing renewable generation curtailment an...A total of 19%of generation capacity in California is offered by PV units and over some months,more than 10%of this energy is curtailed.In this research,a novel approach to reducing renewable generation curtailment and increasing system flexibility by means of electric vehicles'charging coordination is presented.The presented problem is a sequential decision making process,and is solved by a fitted Q-iteration algorithm which unlike other reinforcement learning methods,needs fewer episodes of learning.Three case studies are presented to validate the effectiveness of the proposed approach.These cases include aggregator load following,ramp service and utilization of non-deterministic PV generation.The results suggest that through this framework,EVs successfully learn how to adjust their charging schedule in stochastic scenarios where their trip times,as well as solar power generation are unknown beforehand.展开更多
Shock formation due to flow compressibility and its interaction with boundary layers has adverse effects on aerodynamic characteristics, such as drag increase and flow separation. The objective of this paper is to app...Shock formation due to flow compressibility and its interaction with boundary layers has adverse effects on aerodynamic characteristics, such as drag increase and flow separation. The objective of this paper is to appraise the practicability of weakening shock waves and, hence, reducing the wave drag in transonic flight regime using a two-dimensional jagged wall and thereby to gain an appropriate jagged wall shape for future empirical study. Different shapes of the jagged wall, including rectangular, circular, and triangular shapes, were employed. The numerical method was validated by experimental and numerical studies involving transonic flow over the NACA0012 airfoil, and the results presented here closely match previous experimental and numerical results. The impact of parameters, including shape and the length-to-spacing ratio of a jagged wall, was studied on aerodynamic forces and flow field. The results revealed that applying a jagged wall method on the upper surface of an airfoil changes the shock structure significantly and disintegrates it, which in turn leads to a decrease in wave drag. It was also found that the maximum drag coefficient decrease of around 17 % occurs with a triangular shape, while the maximum increase in aerodynamic efficiency(lift-to-drag ratio)of around 10 % happens with a rectangular shape at an angle of attack of 2.26?.展开更多
Developing the electricity market at the distribution level can facilitate the energy transactions in distribution networks with a high penetration level of distributed energy resources(DERs)and microgrids(MGs).Howeve...Developing the electricity market at the distribution level can facilitate the energy transactions in distribution networks with a high penetration level of distributed energy resources(DERs)and microgrids(MGs).However,the lack of comprehensive information about the marginal production cost of competitors leads to uncertainties in the optimal bidding strategy of participants.The electricity demand within the network and the price in the wholesale electricity market are two other sources of the uncertainties.In this paper,a day-ahead-market-based framework for managing the energy transactions among MGs and other participants in distribution networks is introduced.A game-theory-based method is presented to model the competition and determine the optimal bidding strategy of participants in the market.Robust optimization technique is employed to capture the uncertainties in the marginal cost of competitors.Additionally,the uncertainties in demand are modeled using a scenario-based stochastic approach.The results ob-tained from case studies reveal the merit of considering competition modeling and uncertainties.展开更多
In this paper, towing tank experiments are conducted to study the behavior of flow on a model of the underwater vehicle with various shapes of bows, i.e. tango and standard bows in free surface motion tests. The total...In this paper, towing tank experiments are conducted to study the behavior of flow on a model of the underwater vehicle with various shapes of bows, i.e. tango and standard bows in free surface motion tests. The total resistances for different Froude numbers are considered experimentally. The towing tank is equipped with a trolley that can operate in through 0.05-6 m/s speed with ±0.02 m/s accuracy. Furthermore, the study is done on hydrodynamic coefficients i.e. total, residual and friction resistance coefficients, and the results are compared. Finally, the study on flow of wave fields around bows is done and wave filed around two bows are compared. The Froude number interval is between 0.099 and 0.349. Blockage fraction for the model is fixed to 0.005 3. The results showed that the residual resistance of the standard bow in 0.19 to 0.3 Froude number is more than the tango bow in surface motion which causes more total resistance for the submarine. Finally, details of wave generated by the bow are depicted and the effects of flow pattern on resistance drag are discussed.展开更多
This paper presents an approach to determine the vulnerable components in the electricity and natural gas networks of an islanded microgrid that is exposed to deliberate disruptions. The vulnerable components in the m...This paper presents an approach to determine the vulnerable components in the electricity and natural gas networks of an islanded microgrid that is exposed to deliberate disruptions. The vulnerable components in the microgrid are identified by solving a bi-level optimization problem. The objective of the upper-level problem(the attacker's objective) is to maximize the expected operation cost of microgrid by capturing the penalties associated with the curtailed electricity and heat demands as a result of the disruption. In the lower-level problem, the adverse effects of disruptions and outages in the electricity and natural gas networks are mitigated by leveraging the available resources in the microgrid(the defender's objective). The uncertainties in the electricity and heat demand profiles were captured by introducing scenarios with certain probabilities. The formulated bi-level optimization problem provides effective guidelines for the microgrid operator to adopt the reinforcement strategies in the interdependent natural gas and electricity distribution networks and improve the resilience of energy supply. The presented case study shows that as more components are reinforced in the interdependent energy networks, the reinforcement cost is increased and the expected operation cost as a result of disruption is decreased.展开更多
Noise reduction of different airfoils is important because these sections are used in wind turbines,propellers,and aircraft wings.Several methods are used for passive noise reduction of sections.One of these methods i...Noise reduction of different airfoils is important because these sections are used in wind turbines,propellers,and aircraft wings.Several methods are used for passive noise reduction of sections.One of these methods is the use of surface treatment.In this research,the effect of the typical surface treatment element(finlets)on the vortex structure at different frequencies in the turbulent flow created on the NACA2412 section is investigated.For this purpose,one-dimensional hot wire probe is used.The used surface treatment in this research has a special geometry and the distance between two consecutive finlets is 6 mm(S=6 mm).This study shows that this surface treatment element can be used for noise reduction in high frequencies.Another result of this research is the suggestion of the most suitable position to install this special surface treatment element to reduce vortex energy in all frequency ranges.This installation location is determined based on a dimensionless parameter(X_(aft)/h).展开更多
In this paper, the effects of turbulence on sound generation and velocity fluctuations due to pressure waves in a large subsonic wind tunnel are studied. A trip strip located at different positions in the contraction ...In this paper, the effects of turbulence on sound generation and velocity fluctuations due to pressure waves in a large subsonic wind tunnel are studied. A trip strip located at different positions in the contraction part or at one position in the diffuser of a large wind tunnel is used to investigate the aforementioned phenomenon, and the results indicate that the trip strip has significant effects on sound reduction. The lowest turbulence intensity and sound are obtained from a trip strip with a diameter of 0.91 mm located either at X/L = 0.79 or at X/L = 0.115 in the wide portion of the contraction. Furthermore, the effect of monopole, dipole and quadrupole sources of aerodynamic noise at different velocities is investigated, and it is demonstrated that the contribution of the monopole is dominant, while the shares due to the dipole and quadrupole remain less important. In addition, it is found that the sound waves have a modest impact on the measured longitudinal turbulence and are generated essentially by eddies.展开更多
A flow field around a streamlined body at an intermediate angle of incidence is dominated by cross-flow separation and vortical flow fields. The separated flow leads to a pair of vortices on the leeside of the body; t...A flow field around a streamlined body at an intermediate angle of incidence is dominated by cross-flow separation and vortical flow fields. The separated flow leads to a pair of vortices on the leeside of the body; therefore, it is essential to accurately determine this pair and estimate its size and location. This study utilizes the element-based finite volume method based on RANS equations to compute a 3D axisymmetric flow around a SUBOFF bare submarined hull. Cross-flow vortex structures are then numerically simulated and compared for a submarine with SUBOFF and DRDC STR bows. Computed results of pressure and shear stress distribution on the hull surface and the strength and locations of the vortex structures are presented at an intermediate incidence angle of 20°. A wind tunnel experiment is also conducted to experimentally visualize the vortex structures and measure their core locations. These experimental results are compared with the numerical data, and a good agreement is found.展开更多
A solution to the power flow problem is imperative for many power system applications and several iterative approaches are employed to achieve this objective.However,the chance of finding a solution is dependent on th...A solution to the power flow problem is imperative for many power system applications and several iterative approaches are employed to achieve this objective.However,the chance of finding a solution is dependent on the choice of the initial point because of the nonconvex feasibility region of this problem.In this paper,a non-iterative approach that leverages a convexified relaxed power flow problem is employed to verify the existence of a feasible solution.To ensure the scalability of the proposed convex relaxation,the problem is formulated as a sparse semi-definite programming problem.The variables associated with each maximal clique within the network form several positive semidefinite matrices.Perturbation and network reconfiguration schemes are employed to improve the tightness of the proposed convex relaxation in order to validate the existence of a feasible solution for the original non-convex problem.Multiple case studies including an ill-conditioned power flow problem are examined to show the effectiveness of the proposed approach to find a feasible solution.展开更多
Objective: Depression affects people living with HIV(PLWH) compliance leading to poor control infection.Previous observational studies showed an anti-depression effect of green tea extract(GTE). The therapeutic effect...Objective: Depression affects people living with HIV(PLWH) compliance leading to poor control infection.Previous observational studies showed an anti-depression effect of green tea extract(GTE). The therapeutic effect of GTE on depression were investigated in PLWH receiving antiretroviral therapy(ART).Methods: Fifty PLWH on ART with diagnose of mild to moderate of depression, participated in a doubleblind, placebo-controlled trial and underwent 12 weeks of treatment with either 400 mg GTE capsules or placebo twice daily. The Hamilton depression scale of patients was measured before, 6 weeks and 12 weeks after treatment in two groups. The primary outcome measure was performed to evaluate the efficacy of GTE in improving depressive symptoms.Results: The mean of Hamilton score showed a significant difference between the two groups after 12 weeks(P = 0.035). Repeated measures ANOVA test showed a significant effect for time ? treatment interaction on the Hamilton mean score between the two groups(P = 0.000).Conclusion: It seems the use of GTE capsules in PLWH on ART is safe and could lead to greater and more rapid improvement in depressive symptoms than placebo. Thus it can be considered as an alternative therapy for mild to moderate depression. Further studies with higher sample size and longer followup and comparisons with other antidepressive drugs are warranted.展开更多
The flow fields over a generic cranked double delta wing were investigated. Pressure and velocity distributions were obtained using a Pitot tube and a hot wire anemometer. Two different leading edge shapes, namely "s...The flow fields over a generic cranked double delta wing were investigated. Pressure and velocity distributions were obtained using a Pitot tube and a hot wire anemometer. Two different leading edge shapes, namely "sharp" and "round", were applied to the wing. The wing had two sweep angles of 55° and 30°. The experiments were conducted in a closed circuit wind tunnel at velocity 20 m/s and angles of attack of 5°- 20° with the step of 5°. The Reynolds number of the model was about 2 - 105 according to the root chord. A dual vortex structure was formed above the wing surface. A pressure drop occurred at the vortex core and the root mean square of the measured velocity increased at the core of the vortices, reflecting the instability of the flow in that region. The magnitude of power spectral density increased strongly in spanwise direction and had the maximum value at the vortex core. By increasing the angle of attack, the pressure drop increased and the vortices became wider; the vortices moved inboard along the wing, and away from the surface; the flow separation was initiated from the outer portion of the wing and developed to its inner part. The vortices of the wing of the sharp leading edge were stronger than those of the round one.展开更多
To optimize both the mechanical and biological properties of titanium for biomedical implants,a highly flexible powder metallurgy approach is proposed to generate porous scaffolds with graded porosities and pore sizes...To optimize both the mechanical and biological properties of titanium for biomedical implants,a highly flexible powder metallurgy approach is proposed to generate porous scaffolds with graded porosities and pore sizes.Sugar pellets acting as space holders were compacted with titanium powder and then removed by dissolution in water before sintering.The morphology,pore structure,porosity and pore interconnectivity were observed by optical microscopy and SEM.The results show that the porous titanium has porosity levels and pore size gradients consistent with their design with gradual and smooth transitions at the interfaces between regions of differing porosities and/or pore sizes.Meanwhile,the porous titanium has high interconnectivity between pores and highly spherical pore shapes.In this article we show that this powder metallurgy processing technique,employing the novel sugar pellets as space-holders,can generate porous titanium foams with well-controlled graded porosities and pore sizes.This method has excellent potential for producing porous titanium structures for hard tissue engineering applications.展开更多
文摘Cupping therapy has been widely used for clinical treatment of soft tissue lesions. The current study investigated the effects of cupping therapy on biomechanical properties of the skin in Wistar rats. 20 rats were divided into two groups: 10 in experimental and 10 in control group. Either the right or the left lower quadrants of the lumbar regions in the experimental group underwent 10 minutes daily cupping therapy for 12 days. The skin stiffness and ultimate tensile strength of all the rats were measured using tensiometer. The skin stiffness and ultimate tensile strength were decreased significantly in cupping side of the experimental group as compared with the non-cupping side and the control group. There were no significant differences between the non-cupping side of the experimental group and the control group. In conclusion, cupping therapy can be useful as a treatment method to reduce the skin stiffness and ultimate tensile strength.
基金supported by the Technology Project of State Grid Corporation of China(5100-201958522A-0-0-00).
文摘A total of 19%of generation capacity in California is offered by PV units and over some months,more than 10%of this energy is curtailed.In this research,a novel approach to reducing renewable generation curtailment and increasing system flexibility by means of electric vehicles'charging coordination is presented.The presented problem is a sequential decision making process,and is solved by a fitted Q-iteration algorithm which unlike other reinforcement learning methods,needs fewer episodes of learning.Three case studies are presented to validate the effectiveness of the proposed approach.These cases include aggregator load following,ramp service and utilization of non-deterministic PV generation.The results suggest that through this framework,EVs successfully learn how to adjust their charging schedule in stochastic scenarios where their trip times,as well as solar power generation are unknown beforehand.
文摘Shock formation due to flow compressibility and its interaction with boundary layers has adverse effects on aerodynamic characteristics, such as drag increase and flow separation. The objective of this paper is to appraise the practicability of weakening shock waves and, hence, reducing the wave drag in transonic flight regime using a two-dimensional jagged wall and thereby to gain an appropriate jagged wall shape for future empirical study. Different shapes of the jagged wall, including rectangular, circular, and triangular shapes, were employed. The numerical method was validated by experimental and numerical studies involving transonic flow over the NACA0012 airfoil, and the results presented here closely match previous experimental and numerical results. The impact of parameters, including shape and the length-to-spacing ratio of a jagged wall, was studied on aerodynamic forces and flow field. The results revealed that applying a jagged wall method on the upper surface of an airfoil changes the shock structure significantly and disintegrates it, which in turn leads to a decrease in wave drag. It was also found that the maximum drag coefficient decrease of around 17 % occurs with a triangular shape, while the maximum increase in aerodynamic efficiency(lift-to-drag ratio)of around 10 % happens with a rectangular shape at an angle of attack of 2.26?.
文摘Developing the electricity market at the distribution level can facilitate the energy transactions in distribution networks with a high penetration level of distributed energy resources(DERs)and microgrids(MGs).However,the lack of comprehensive information about the marginal production cost of competitors leads to uncertainties in the optimal bidding strategy of participants.The electricity demand within the network and the price in the wholesale electricity market are two other sources of the uncertainties.In this paper,a day-ahead-market-based framework for managing the energy transactions among MGs and other participants in distribution networks is introduced.A game-theory-based method is presented to model the competition and determine the optimal bidding strategy of participants in the market.Robust optimization technique is employed to capture the uncertainties in the marginal cost of competitors.Additionally,the uncertainties in demand are modeled using a scenario-based stochastic approach.The results ob-tained from case studies reveal the merit of considering competition modeling and uncertainties.
文摘In this paper, towing tank experiments are conducted to study the behavior of flow on a model of the underwater vehicle with various shapes of bows, i.e. tango and standard bows in free surface motion tests. The total resistances for different Froude numbers are considered experimentally. The towing tank is equipped with a trolley that can operate in through 0.05-6 m/s speed with ±0.02 m/s accuracy. Furthermore, the study is done on hydrodynamic coefficients i.e. total, residual and friction resistance coefficients, and the results are compared. Finally, the study on flow of wave fields around bows is done and wave filed around two bows are compared. The Froude number interval is between 0.099 and 0.349. Blockage fraction for the model is fixed to 0.005 3. The results showed that the residual resistance of the standard bow in 0.19 to 0.3 Froude number is more than the tango bow in surface motion which causes more total resistance for the submarine. Finally, details of wave generated by the bow are depicted and the effects of flow pattern on resistance drag are discussed.
文摘This paper presents an approach to determine the vulnerable components in the electricity and natural gas networks of an islanded microgrid that is exposed to deliberate disruptions. The vulnerable components in the microgrid are identified by solving a bi-level optimization problem. The objective of the upper-level problem(the attacker's objective) is to maximize the expected operation cost of microgrid by capturing the penalties associated with the curtailed electricity and heat demands as a result of the disruption. In the lower-level problem, the adverse effects of disruptions and outages in the electricity and natural gas networks are mitigated by leveraging the available resources in the microgrid(the defender's objective). The uncertainties in the electricity and heat demand profiles were captured by introducing scenarios with certain probabilities. The formulated bi-level optimization problem provides effective guidelines for the microgrid operator to adopt the reinforcement strategies in the interdependent natural gas and electricity distribution networks and improve the resilience of energy supply. The presented case study shows that as more components are reinforced in the interdependent energy networks, the reinforcement cost is increased and the expected operation cost as a result of disruption is decreased.
文摘Noise reduction of different airfoils is important because these sections are used in wind turbines,propellers,and aircraft wings.Several methods are used for passive noise reduction of sections.One of these methods is the use of surface treatment.In this research,the effect of the typical surface treatment element(finlets)on the vortex structure at different frequencies in the turbulent flow created on the NACA2412 section is investigated.For this purpose,one-dimensional hot wire probe is used.The used surface treatment in this research has a special geometry and the distance between two consecutive finlets is 6 mm(S=6 mm).This study shows that this surface treatment element can be used for noise reduction in high frequencies.Another result of this research is the suggestion of the most suitable position to install this special surface treatment element to reduce vortex energy in all frequency ranges.This installation location is determined based on a dimensionless parameter(X_(aft)/h).
基金supported by the Iranian Aircraft Manufacturing (HESA) company,Bureau of Aircraft Design
文摘In this paper, the effects of turbulence on sound generation and velocity fluctuations due to pressure waves in a large subsonic wind tunnel are studied. A trip strip located at different positions in the contraction part or at one position in the diffuser of a large wind tunnel is used to investigate the aforementioned phenomenon, and the results indicate that the trip strip has significant effects on sound reduction. The lowest turbulence intensity and sound are obtained from a trip strip with a diameter of 0.91 mm located either at X/L = 0.79 or at X/L = 0.115 in the wide portion of the contraction. Furthermore, the effect of monopole, dipole and quadrupole sources of aerodynamic noise at different velocities is investigated, and it is demonstrated that the contribution of the monopole is dominant, while the shares due to the dipole and quadrupole remain less important. In addition, it is found that the sound waves have a modest impact on the measured longitudinal turbulence and are generated essentially by eddies.
文摘A flow field around a streamlined body at an intermediate angle of incidence is dominated by cross-flow separation and vortical flow fields. The separated flow leads to a pair of vortices on the leeside of the body; therefore, it is essential to accurately determine this pair and estimate its size and location. This study utilizes the element-based finite volume method based on RANS equations to compute a 3D axisymmetric flow around a SUBOFF bare submarined hull. Cross-flow vortex structures are then numerically simulated and compared for a submarine with SUBOFF and DRDC STR bows. Computed results of pressure and shear stress distribution on the hull surface and the strength and locations of the vortex structures are presented at an intermediate incidence angle of 20°. A wind tunnel experiment is also conducted to experimentally visualize the vortex structures and measure their core locations. These experimental results are compared with the numerical data, and a good agreement is found.
基金supported by Technology Project of State Grid Corporation of China(No.SGRIJSKJ(2016)800).
文摘A solution to the power flow problem is imperative for many power system applications and several iterative approaches are employed to achieve this objective.However,the chance of finding a solution is dependent on the choice of the initial point because of the nonconvex feasibility region of this problem.In this paper,a non-iterative approach that leverages a convexified relaxed power flow problem is employed to verify the existence of a feasible solution.To ensure the scalability of the proposed convex relaxation,the problem is formulated as a sparse semi-definite programming problem.The variables associated with each maximal clique within the network form several positive semidefinite matrices.Perturbation and network reconfiguration schemes are employed to improve the tightness of the proposed convex relaxation in order to validate the existence of a feasible solution for the original non-convex problem.Multiple case studies including an ill-conditioned power flow problem are examined to show the effectiveness of the proposed approach to find a feasible solution.
基金financial support of the Vice-Chancellor of Research in Tehran University of Medical Sciences (TUMS)。
文摘Objective: Depression affects people living with HIV(PLWH) compliance leading to poor control infection.Previous observational studies showed an anti-depression effect of green tea extract(GTE). The therapeutic effect of GTE on depression were investigated in PLWH receiving antiretroviral therapy(ART).Methods: Fifty PLWH on ART with diagnose of mild to moderate of depression, participated in a doubleblind, placebo-controlled trial and underwent 12 weeks of treatment with either 400 mg GTE capsules or placebo twice daily. The Hamilton depression scale of patients was measured before, 6 weeks and 12 weeks after treatment in two groups. The primary outcome measure was performed to evaluate the efficacy of GTE in improving depressive symptoms.Results: The mean of Hamilton score showed a significant difference between the two groups after 12 weeks(P = 0.035). Repeated measures ANOVA test showed a significant effect for time ? treatment interaction on the Hamilton mean score between the two groups(P = 0.000).Conclusion: It seems the use of GTE capsules in PLWH on ART is safe and could lead to greater and more rapid improvement in depressive symptoms than placebo. Thus it can be considered as an alternative therapy for mild to moderate depression. Further studies with higher sample size and longer followup and comparisons with other antidepressive drugs are warranted.
文摘The flow fields over a generic cranked double delta wing were investigated. Pressure and velocity distributions were obtained using a Pitot tube and a hot wire anemometer. Two different leading edge shapes, namely "sharp" and "round", were applied to the wing. The wing had two sweep angles of 55° and 30°. The experiments were conducted in a closed circuit wind tunnel at velocity 20 m/s and angles of attack of 5°- 20° with the step of 5°. The Reynolds number of the model was about 2 - 105 according to the root chord. A dual vortex structure was formed above the wing surface. A pressure drop occurred at the vortex core and the root mean square of the measured velocity increased at the core of the vortices, reflecting the instability of the flow in that region. The magnitude of power spectral density increased strongly in spanwise direction and had the maximum value at the vortex core. By increasing the angle of attack, the pressure drop increased and the vortices became wider; the vortices moved inboard along the wing, and away from the surface; the flow separation was initiated from the outer portion of the wing and developed to its inner part. The vortices of the wing of the sharp leading edge were stronger than those of the round one.
基金the support of the ARC Research Hub for Advanced Manufacturing of Medical Devices(IH150100024)M.J.Bermingham acknowledges the support of the ARC Discovery Early Career Researcher Awards(DE160100260).
文摘To optimize both the mechanical and biological properties of titanium for biomedical implants,a highly flexible powder metallurgy approach is proposed to generate porous scaffolds with graded porosities and pore sizes.Sugar pellets acting as space holders were compacted with titanium powder and then removed by dissolution in water before sintering.The morphology,pore structure,porosity and pore interconnectivity were observed by optical microscopy and SEM.The results show that the porous titanium has porosity levels and pore size gradients consistent with their design with gradual and smooth transitions at the interfaces between regions of differing porosities and/or pore sizes.Meanwhile,the porous titanium has high interconnectivity between pores and highly spherical pore shapes.In this article we show that this powder metallurgy processing technique,employing the novel sugar pellets as space-holders,can generate porous titanium foams with well-controlled graded porosities and pore sizes.This method has excellent potential for producing porous titanium structures for hard tissue engineering applications.