Search

Introduction: Ginseng is a medicinal herb. Cyclophosphamide is also an anti-cancer drug with side effects on the ovaries. The purpose of this study is to investigate the effect of the hydroalcoholic extract of ginseng on detoxifying cyclophosphamide in the ovary tissue of adult female rats. Materials & Methods: The present experimental study was conducted on 56 adult female rats. The rats were randomly divided into 7 groups of 8 each, including the negative control group, the sham control group and the experimental groups 1, 2, 3, 4 and 5. The negative control group received no drugs, while the sham control group was given solvent. Experimental groups 1, 2 and 3 received a daily dose of 5 mg/kg/bw cyclophosphamide and an additional dose of 0.5, 1 and 2 g/kg/bw ginseng extract. Experimental group 4 received a daily dose of 5 mg/kg/bw cyclophosphamide and experimental group 5 received a daily dose of 2 g/kg/bw ginseng extract. Their ovary tissue sections were then prepared and examined. Results: In experimental group 1, follicular atresia occurred to a great extent; however, in experimental group 2, the extent of follicular atresia and tissue destruction was observed to be lower than in experimental group 1. In experimental group 3, follicular atresia reduced compared to in experimental groups 1 and 2, but in experimental group 4, follicular atresia occurred to a much greater extent. In experimental group 5, the number of graafian, primary and secondary follicles increased compared to the negative control group. Conclusions: Cyclophosphamide increases the extent of follicular atresia, while the hydroalcoholic extract of ginseng prevents the side effects of cyclophosphamide from setting in and thereby reduces the extent of follicular atresiafollicles. [ABSTRACT FROM AUTHOR]

Background & Objectives: Lead as a naturally-occurring element has different effects on hematopoitic system, nervous system, kidney, reproductive system and bone. In this investigation, was determined the effect of garlic alcoholic-water extract in kidney poisoning treatment induced by lead in neonatal rat. Materials & Methods: Rats were divided into 7 groups of 8. The First group was the control group, which had received no materials. The second group had received 0/1 ml distilled water, the third group had received the lead with a dose of 0/6 gram per liter. The forth group had just received 0/4 g/kg garlic alcoholic -- water extract. The fifth, sixth, and seventh group had first received 0/6 g lead perliter and then received doses of 0/1, 0/2, 0/4 g/kg garlic. Then, injections was performed orally in 10 consecutive days. The data were analysed then using T. Results: Based on the obtained results, there is a significant increase in the body weight and the kidney of the third, fifth, sixth and seventh groups compared with the control group. However, the body weight and kidney of rats in the fourth group showed a meaningful decrease comparing with the lead group. Regarding the third group, there was a meaningful increase in Urea, uric acid, creatinine and potassium compared with the control group but a significant decrease in the sodium. Conclusion: Protective effects of garlic on kidney are related to antioxidant properties, since different types of oxidation reactions have negative effects on glomerular filtration rate. Garlic is eliminating the poisoning effect of lead on the kidney because of having properties such as antioxidant and protective effect. [ABSTRACT FROM AUTHOR]

The flowfield around a model MC-4 ram-air personnel parachute canopy was examined using the steady, incompressible Navier-Stokes equations together with the one-equation Spalart-AIImaras turbulence model. A finite volume flow solver was used to compute the flowfield, forces, and moments on the canopy in steady glide and at sideslip. The canopy surfaces were assumed to be impermeable and rigid. The oncoming flow barely penetrates the canopy opening, and creates a large separation bubble below the lower lip of each half-cell. The flow does not reattach, and a thick boundary layer is present on the lower surface of the canopy. The flow over the upper surface of the canopy remains attached until the separation point near the trailing edge. The lift increases linearly with the angle of attack up to about 12 deg, whereas the quarter-chord pitching moment decreases nearly linearly between 2 and 12 deg angle of attack. For sideslip angles up to 20 deg, the side force increases linearly with the sideslip angle even as the lift remains nearly constant. The yawing moment also increases linearly with the sideslip angle, whereas the rolling moment varies quadratically. The fidelity of the lifting-line theory in predicting the forces on the canopy during steady glide was assessed. [ABSTRACT FROM AUTHOR]

The velocity field of isolated turbulent puffs was measured using the particle image velocimetry technique and was compared with the steady jet flow field. Puffs were generated by injecting air through a 5 mm diameter nozzle into a flow chamber with a weak coflow. Isolated puffs with a Reynolds number of 5000 were examined in the range of 40-75 diameters downstream of the nozzle. The injection time was varied in order to assess the effects of injection volume and equivalent stroke ratio on the puff structure. The results from phase-locked measurements indicate that as the injection volume increased, puffs elongated in the axial direction and became similar to starting jets in the range considered. The largest scaled fluctuating velocities and turbulent shear stress within the puffs were twice the steady jet values. Inspection of the vorticity field revealed the presence of vorticity throughout the puff volume. Entrainment takes place on the portion of the puff closest to the nozzle and the entrainment rate is greater for the puffs with the smaller injection volume. This is consistent with the observations of rapid mixing and combustion of puffs in previous studies. [ABSTRACT FROM AUTHOR]

The development of a buoyant vortex ring in the near field was examined experimentally, and the findings were compared with those of a non-buoyant ring with a similar Reynolds number. The experiments were performed in a water tank, and the vortices were produced by a cylindrical tube of aspect ratio 2. Laser sheet flow visualization and PIV measurements were carried out. In the near field, the initial column of the buoyant fluid breaks down due to the presence of Rayleigh–Taylor instability at the buoyant fluid interface. Subsequently, a large diameter vortex ring with a large spreading rate, compared with the non-buoyant ring, emerges. The celerity of buoyant vortex continued to decrease throughout the range examined, in contrast to the constant celerity of the non-buoyant ring. The vorticity in the core of buoyant and non-buoyant vortex rings is symmetric and has a Gaussian distribution. However, the buoyant vortex ring evolves into a thin core ring, whereas the non-buoyant ring becomes a thick core ring shortly after the ring formation. This difference is brought on by the rapid entrainment and the significant growth of the buoyant ring following the breakup of the initial formation. [ABSTRACT FROM AUTHOR]

Abstract: The interaction of a rectilinear vortex with an inflated round parachute canopy model was studied experimentally in a water tunnel where the vortex core was aligned with the axis of the canopy. Three different canopy diameters were used, and the canopy model was attached to a streamlined forebody. Dye flow visualization indicated that vortex breakdown was present when the core trajectory was within the canopy opening. Vortex breakdown occurred about one to two canopy diameters upstream of the canopy opening. The vortex core completely disintegrated when it interacted with the forebody near the canopy centerline. The vortex breakdown and disintegration caused unsteady, asymmetric deformations on the canopy surface. A reduction in the time-averaged drag and an increase in the fluctuating drag was observed when the vortex core was within the canopy opening. The disintegration of the vortex core near the canopy centerline lessened the drag reduction brought on by the presence of the core. [Copyright &y& Elsevier]

Abstract: The effects of buoyancy in pulsed turbulent jet diffusion flames were investigated by conducting experiments in both microgravity and normal gravity. In all cases the flames were fully modulated; that is, the fuel flow was completely shut off between pulses. Unheated ethylene fuel was injected using a 2-mm-diameter nozzle into a combustor with an oxidizer coflow at ambient pressure. Microgravity conditions () were achieved for 2.2 s in drop tower tests. Flames with short injection times and high duty cycle exhibit a marked increase in the ensemble-averaged flame length due to the removal of buoyancy. For other injection conditions, including steady state injection, the flame length is not strongly impacted by buoyancy. The significant increases in flame length with injection duty cycle are consistent with the duty cycle near the flame tip of microgravity flames exceeding that of normal gravity flames. The celerity of isolated compact flame puffs is approximately 40% less in microgravity than in normal gravity. An analytical argument indicates that duty cycle near the flame tip can significantly exceed that at injection due to the combination of a puff growth and the decrease in the celerity of the flame puffs with downstream distance. This effect is predicted to be significantly greater in the absence of buoyancy and for shorter injection times, in qualitative agreement with the experiments. The cycle-averaged centerline temperatures were generally higher in the microgravity flames than in normal gravity, especially at the flame tip where the difference was as much as 200 K. [Copyright &y& Elsevier]

The evolution of a pulsed vortex generator jet embedded in a turbulent boundary layer was examined experimentally. The jet, which was pitched 45 deg and skewed 90 deg, had a velocity three times greater than the freestream. The velocity field in planes normal to the freestream was measured by the particle-image-velocimetry method at four stations downstream of the jet exit. The pulsed jet created a starting vortex ring followed by a pair of counter-rotating streamwise vortices, one of them being markedly stronger. Phase-averaged data indicate that the maximum circulation and peak vorticity of the stronger vortex are approximately 30% greater than the average values for a steady jet with the same velocity. However, circulation averaged over the entire pulse was less than that for a steady jet at the same location. The core of the primary streamwise vortex penetrates approximately 50% farther into the boundary layer than a steady jet with the same velocity. The larger penetration takes place during the initial portion of the pulse and is caused by the jet starting vortex ring. [ABSTRACT FROM AUTHOR]

Presents a study that investigated the parameters that affect the inflation of solid-cloth, flat circular parachute canopies. Dimensional analysis of the parameters in relevance to the performance of the entire parachute system; Comparison of the parameters for full and small-scale solid-cloth, flat circular canopies in air and water; Correlation of the filling and opening times applicable to very small-scale models and full-scale parachutes; Role of permeability in the production of canopy proportionality factors.

The near wake of an impulsively started disk was studied computationally by a finite element code with a Smagorinsky turbulence model. The shear layer separating from the disk lip rolled up into a symmetric starting vortex ring at first. As time evolved, the vortex stretched in the downstream direction and flow instabilities caused the vortex ring to become wavy eventually leading to the breakup of the ring. The complete breakup and shedding of the starting vortex ring took a time of approximately 14D/U, where D is the disk diameter and U is the freestream velocity. The starting vortex ring circulation attained a plateau of ≈2.6UD at a time of about 4D/U, in good agreement with the experimental findings by Balligand (2000). The radial circulation profiles are Gaussian during the symmetric phase and collapse together at a time of 4D/U. Beyond this time, the vortex ring celerity is constant and vorticity extends to the symmetry axis. The base pressure coefficient becomes positive as the vortex ring moves away from the disk and remains positive until the ring is completely shed. The breakup of the starting vortex ring is concurrent with the appearance of an azimuthal pressure gradient and core flow. Following the breakup of the starting vortex ring, the flow became three-dimensional and settled into an open wake. The mean drag and base pressure coefficients were nearly constant after a time of approximately 30D/U and matched very well against experimental data. [ABSTRACT FROM AUTHOR]

Provides information on a study which examined the temporal evolution of the flowfield in the near wake of a parachute canopy. Methods used in the computation of flowfields; Use of finite element formulation in the computation of the flowfield; Phases of the development of the starting flow around a rigid parachute canopy.

Presents a study of fully modulated turbulent transverse jets in a water tunnel over a range of pulsing frequencies and duty cycles and at two jet-to-crossflow velocity ratios. Experimental setup; Use of a planar laser-induced fluorescence technique; Summary and conclusions.

Presents information on a study which examined the variation of the delta-wing primary vortices using ultrasound techniques. Experimental details; Results and discussion; Conclusions.

Investigates laminar vortex rings propagating horizontally in linearly stratified media in a water tank using the laser-induced fluorescence flow visualization technique. Vortex rings' development of an asymmetry where the upper part of the ring became larger in the cross-sectional area than the lower part; Instability of the interface on the upper portion of the ring.

Investigates the effects of acceleration on turbulent jets in a series of flow visualization experiments. Use of linear, quadratic and exponential schemes of acceleration; Model based on the scaling of centerline velocity in steady jets; Nozzle exit velocity.

Investigates the minimum mixing rate of turbulent vortex rings in water tank by employing an aqueous acid-base reaction. Generation of vortex rings by a simple apparatus with a cylindrical geometry; Released fluid surrounding the vortex core; Fluid in the toroidal core.

Studies the starting vortex of an impulsively generated jet diffusion flame. Stationary jet flame length; Starting vortex penetration; Lateral spreading; Dependence of penetration on nozzle diameter.

Discusses the structure and mixing of impulsively started jets in a water tank utilizing an acid-base reaction. Separation of the starting vortex from the rest of the jet in the near field; Celerity of the jet tip; Mixing of the fluid in the vicinity of the jet tip with the ambient fluid; Enlargement of the region near the jet tip with improved mixing.

Presents information on a study which compared the vortex circulation measured by ultrasound model against other data to assess the applicability of the ultrasound technique. Description of the ultrasound method; Experimental setup; Findings and summary.

The minimum molecular scale mixing rate of the turbulent plume was found by measurements of the plume ‘‘flame length’’ under various initial conditions. A simple derivation based on the self-similar properties of plumes provides power law relations for the mixing rate, which agree well with the experiments. [ABSTRACT FROM AUTHOR]

Introduction:Artemisia absinthium, also know as wormwood, ontains numerous ingredients including cis-chrysanthenyl acetate, cis- chrysanthenyl, cis-epoxyocimen, sabinyl acetate, Bornyl acetate, and alpha-and beta-Thujones. Alpha-and beta-Thujones are toxic ingredients of this plant. This research tended to evaluate the effect of Artemisia absinthium on male rats' spermatogenesis and its concurrent hormonal changes. Materials and Methods:After being synchronized, 40 male mature Wistar rats weighing 250±50 grams were divided into five equal groups including control group, sham group, and three experimental groups. The control group received no medicine. The sham group received physiological serum with intraperitoneal injection. The experimental groups 1, 2, and 3 received respectively 125, 250, and 500 mg/kg/bw of Artemisia absinthium hydroalcoholic extracts as intraperitoneal injections. The rats were anatomized after treatment period. The parameters involved in this study included: counting the number of spermatogenic cells, spermatoyte, spermatozoid, sperm, generative layer diameter, sperm-maker tube diameter, lumen diameter of sperm-maker tube, LH, FSH, testosterone, and body weight changes. Results:Findings showed that body weight, leydig cell, sperm- maker tube diameter, generative layer diameter, and LH hormone density reduced significantly in the three experimental groups. spermatogenic cell, sperm numbers, and lumen diameter of the spermmaker tube reduced significantly in experimental group 3. The number of spermatocyte and spermatozoid cell reduced significantly in experimental groups 2, and 3. Conclusion:Findings imply Artemisia absinthium extract probably reduces spermatozoon, male sexual cells, and also sexual hormones due to the toxic ingredients included in this extract. Therefore, it should be applied more cautiously. [ABSTRACT FROM AUTHOR]

Lift, drag, and pitching moments of airfoils with leading-edge sinusoidal protuberances were measured in a water tunnel and compared with those of a baseline 634-021 airfoil. The amplitude of the leading-edge protuberances ranged from 2.5 to 12% of the mean chord length; the spanwise wavelengths were 25 and 50% of the mean chord length. These ranges correspond to the morphology found on the leading edge of humpback whales' flippers. Flow visualization using tufts was also performed to examine the separation characteristics of the airfoils. For angles of attack less than the baseline stall angle, lift reduction and drag increase were observed for the modified foils. Above this angle, lift of the modified foils was up to 50% greater than the baseline foil with little or no drag penalty. The amplitude of the protuberances had a distinct effect on the performance of the airfoils, whereas the wavelength had little. Flow visualization indicated separated flow originating primarily from the troughs and attached flow on the peaks of the protuberances at angles beyond the stall angle of the baseline foil. [ABSTRACT FROM AUTHOR]

A series of water-tunnel experiments were conducted to determine the effect of sinusoidal leading-edge protuberances on the aerodynamic characteristics of finite span wings. The models consisted of seven rectangular planform wings, two swept-leading-edge wings, and two wings with a planform resembling humpback-whale flippers. All models had an underlying NACA 634-021 profile with protuberance amplitudes of 0.025-0.12 times the chord length. The models were examined at Reynolds numbers up to 4.5 × 105 and angles of attack up to 30 deg. The lift and drag coefficients were nearly independent of Reynolds numbers above 3.6 × 105. Specific rectangular-planform models had appreciably greater lift coefficients over a limited angle-of-attack range when compared to the baseline model. However, with the exception of the planform that resembled the humpback-whale flipper, the lift-to-drag ratio of all leading-edge modified models was comparable to or less than the equivalent baseline model. The flipper model had a slightly smaller drag coefficient than its baseline counterpart from 17 to 21 deg. The drag of all other models examined was equal to or greater than the corresponding baseline for the entire angle-of-attack range examined. The presence of leading-edge protuberances reduced the span efficiency of the rectangular-planform wings when compared to the baseline, and the primary parameter affecting the span efficiency was the protuberance amplitude. [ABSTRACT FROM AUTHOR]

Introduction: Humans have long noted the importance of memory in learning and have always sought the ways to improve memory and prevent its weaknesses. In the current study, the effect of Nigella sativa extract on learning and memory of adult male rats was investigated. Materials and Methods: In the current experimental study, 40 adult male rats weighing 180-220 g were divided into five groups of eight rates including experimental groups 1, 2 and 3, which were given daily doses of 100, 200 and 400 mg/kg per body weight extracts of Nigella sativa for 17 days, control group (0.1 ml normal saline gavage) and negative control group (received no substance). The extract was administered 12 days before training and continued throughout the training. On the eighteenth day of the administration of the extract, the memory test was conducted by Barnes maze and latency to reach the target and the number of errors was measured. Results: The results showed that learning and spatial memory in groups that receive Nigella sativa extract significantly increased (P<0.05) compared to the control and negative control groups. Conclusions: The results suggest that the administration of Nigella sativa extract can enhance spatial memory and learning due to oleic acid, linoleic acid and antioxidant compounds. [ABSTRACT FROM AUTHOR]

Introduction: Pumpkin seed has been used in traditional medicine as a drug for improving sexual function and vigor. We did not find sufficient scientific evidence to support it. The present study was designed to evaluate the effect of hydroalcoholic extract of pumpkin seeds on hormone-pituitary-ovarian axis and oogenesis in immature rats. Materials and Methods: In this experimental study, we used 30 immature female Wistar rats (weight range 100 to 80 g and 35-30 days old) were randomly selected and divided into five groups of six, three experimental groups, control and sham groups. The experimental group was injected 200,100,50 mg/ kg dose of pumpkin seed extract intraperitoneally for 21 consecutive days. One day after the last injection, blood was taken from the rats to investigate the sex hormones, and then their ovaries were removed for histological studies. Results: The results showed a significant increase in the mean serum FSH, estrogen and progesterone in the experimental groups compared to the sham and control (P<0.05). Secondary follicles in the experimental group compared to the sham and control groups showed a significant increase (P<0.05). Body weight and weight of the right and left ovaries in the experimental group increased (P<0.05). Amongst the other parameters, no significant differences were observed in all groups. Conclusions: Injection of hydroalcoholic extract of pumpkin seeds could significantly be effective on oogenesis and concentration of FSH, estrogen and progesterone hormones. [ABSTRACT FROM AUTHOR]

Introduction: Pumpkin seeds are used in traditional medicine as a drug for improving sexual function and vigor. The present study was designed to evaluate the effect of hydroalcoholic of pumpkin seed extract on FSHserum levels inimmature rats. Materials and Methods:In this experimental study, 30 immature female Wistar rats (weighing 80-100 grams and aging 30-35 days old) were selected and randomly divided into five groups, each containing six rats; the groups were organized into three experimental groups, one control group and one sham group. Experimental groups were injected 200, 100, 50 mg/kg doses of pumpkin seed extract intraperitoneally for 21 consecutive days. For examining sex hormones, blood samples were taken from rats one day following the last injection, and their ovaries were removed for histological studies. Results: The findings showed significant increase in the mean FSH serum in experimental groups as compared to the sham and control groups (P<0.05). Secondary follicles showed significant increase (P<0.05) in experimental groups as compared to the sham and control groups. Conclusions: Injection of hydroalcoholic of pumpkin seed extract can significantly increase oogenesis, FSH concentration, estrogen, and progesterone. [ABSTRACT FROM AUTHOR]

The flowfield and the aerodynamic forces on a two-dimensional airfoil with sinusoidal leading-edge protuberances were computed numerically and compared with the baseline NASA 634-021 airfoil. The amplitude and wavelength of the sinusoidal leading edge were 12 and 50% of the mean chord length. The sinusoidal leading-edge airfoil is dominated by the flow around and over the protuberances at all angles of attack, resulting in significant spanwise variation in all flow properties, in contrast to the baseline airfoil. The surface-pressure distribution on the modified airfoil consists of low-pressure pockets in the troughs that are symmetric and periodic at low angles of attack, and evolve into complicated patterns at higher angles. The low-pressure pockets persist to high angles of attack, resulting in the continued increase of lift. The modified airfoil has lower lift and higher drag in the prestall regime. The lift and drag characteristics at high angles of attack, as well as the dependence on Reynolds number, are addressed in this study. [ABSTRACT FROM AUTHOR]