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In the present study, entropy generation in a non-axisymmetric steady-state incompressible viscous flow over a single rotating porous disk is investigated analytically. The dimensionless form of the local and total entropy generation caused by frictional and thermal effects are derived. The effects of the injection rate and Brinkman number on the entropy generation are revealed. It is found that there exists an optimal injection rate for each Brinkman number, which minimizes the total entropy generation. [ABSTRACT FROM AUTHOR]

This numerical investigation aims to study the turbulent characteristics and thermal enhancement parameter of CuO–water nanofluids through heat exchangers enhanced with double V-cut twisted tapes. The twist ratio of the twisted tapes is 5.25, and the cut ratio (b/c) is varied from 0 (conventional twisted tape) to 1.8. The Reynolds number is in the range of 5000–15,000, and nanoparticles volume fraction is in the range of 0 < ϕ < 1.5 % . The flow is fully turbulent, and (RNG) k − ϵ turbulent model is used for the numerical analysis. The results reveal that strong turbulent kinetic energy and additional vortex flow through the cuts of the modified twisted tapes are the main reason for better fluid mixing and heat transfer enhancement. The heat transfer enhances about 14.5% for the case of ϕ = 1.5 % . Furthermore, using double V-cut twisted tapes improves the Nusselt number of the nanofluid flow inside heat exchangers about 138% compared to conventional twisted tape without cuts. The maximum value of the thermal performance η = 1.99 is achieved by using nanofluid with ϕ = 1.5 % and b/c = 1.8 at Re = 5000. [ABSTRACT FROM AUTHOR]

In this paper, the work and performance of the premixed methane-air porous axisymmetrical burner have firstly been simulated numerically using the CFD tools. For this purpose the set of governing equations has been enriched by an additional energy equation in porous solid, and the chemical species transport has been extended onto the multi-step mechanism (GRI-2-11). This numerical model has been verified on the base of available benchmark experiments. Next, we have studied the local entropy generation problem taking into account not only classical contributions like viscous and turbulent dissipation but also, the porous combustion of gases. The results showed that the greatest portion of entropy generation in the porous medium burner is related to chemical reactions, followed by heat transfer, mass diffusion (mixing) and friction (viscous dissipation), respectively. According to the results, as the excess air ratio increases, the local entropy generation rate due to heat transfer and friction increases and the local entropy generation rate due to chemical reactions is decreased. Also, by increasing the volumetric heat transfer coefficient, the local entropy generation rate due to heat transfer decreases and the local entropy generation rate due to friction and chemical reactions increases. Also, the local entropy generation rate due to mixing does not show a significant change with the changing excess air ratio and volumetric heat transfer coefficient. [ABSTRACT FROM AUTHOR]

Entropy generation analysis for the Cu–water nanofluid flow through a heat exchanger tube equipped with perforated conical rings is numerically investigated. Frictional and thermal entropy generation rates are defined as functions of velocity and temperature gradients. Governing equations are solved by using finite volume method, and Reynolds number is in the range of 5000–15,000. The effects of geometrical and physical parameters such as Reynolds number, number of holes and nanoparticles volume fraction on the thermal and viscous entropy generation rates and Bejan number are investigated. The results indicate that the thermal irreversibility is dominant in most part of the tube. But it decreases with increasing the nanoparticle volume fraction. Frictional entropy generation reduces with increasing the number of holes from 4 to 10. This is because of stronger velocity gradient near the perforated holes. Bejan number decreases with augment of Reynolds number. [ABSTRACT FROM AUTHOR]

Two-phase liquid flow in micro-/mini-channels has several thermal advantages in comparison with single-phase liquid flow, such as heat transfer rate, thermosiphon effect and isothermal heat sinks. Multiphase flows in microfluidic devices are usually used as an effective way to improve the cooling process, since phase change process can provide high heat transfer coefficient in comparison with single-phase flows. On the other hand, high surface-to-volume ratio of microheat exchangers can intensify the overall heat rejection from the system. In the current research, three models, namely (a) the formation of interior and exterior phase, (b) hydrodynamics of droplets during condensation process in a diffusive oblique fin (mini-channel) with hydrophilic walls and (c) liquid evacuation from the channel, are investigated by means of a novel perspective of pseudo-potential lattice Boltzmann model. The effects of channel slope angle on velocity profiles and outlet mass flow rate of the condensed liquid are analyzed. The results show that the slope angle plays an important role at the rate of droplet nucleation and on evacuation time. It is observed that the variation of liquid profile at the channel outlet can be neglected at angles more than 45°. Finally, it is revealed that the required time for droplets coalescence and discharging liquid from the mini-channel can be controlled by optimizing the channel angle. [ABSTRACT FROM AUTHOR]

This study prepares an experimental examination of thermal and hydraulic analysis of an absorber plate integrated with different arrangements of twisted turbulators, including longitudinal, transversal, and oblique orientations. These arrangements are considered for both the integral and the interrupted turbulators over Reynolds number range from 9174 to 55048. Nu ratio and f ratio range from 1.15–2.21 and 1.73–7.79, respectively. The interrupted turbulators with oblique arrangements with the attach angles of 30° and 60° come in the second and third places, respectively, and the maximum criterion value in the latter cases is 1.29 and 1.21. [ABSTRACT FROM AUTHOR]

• The effect of an external magnetic field on hemodynamics of blood flow in a bend vessel was studied. • Blood was studied as a biomagnetic fluid through the ferrohydrodynamic approach. • Effect of curvature coefficient and the susceptibility of blood were investigated. • The maximum magnetic field strength with no effect on hemodynamics was presented. Targeted delivery of therapeutic agents such as stem cells and drugs using magnetic nanoparticles with the aid of an external magnetic field is an emerging treatment modality for many diseases. To this end, understanding the effect of magnetic field on hemodynamics in human body is of great importance. In this article, the effect of external magnetic field, induced by a straight current wire, on hemodynamics of blood flow in a 90° horizontal bend vessel with circular cross section was investigated numerically using ANSYS Fluent®. The blood was considered as laminar, Newtonian, steady and incompressible. To investigate the effect of non-uniform magnetic field effects on the blood flow, the ferrohydrodynamics principles (FHD) were employed. A user-defined function (UDF) was developed to apply the magnetic field effects as source terms. The magnetic susceptibility of blood in oxygenated (in arteries) and deoxygenated (in veins) blood vessels were considered negative and positive values, respectively. The effect of magnetic number, Reynolds number, curvature coefficient and the position of the current wire on flow velocity, static pressure, and shear stress were investigated. The results showed that the Wall Shear Stress (WSS) and static pressure were enhanced with the increase of magnitude of magnetic number. In addition, it was observed that magnetic field has superior impact on the hemodynamic of venous vessel (deoxygenated blood) in comparison with the hemodynamic of artery vessel (oxygenated blood). By studying the effect of curvature coefficient and Reynolds number on WSS, it is concluded that in high curvature coefficient and low Reynolds number, the effect of magnetic field is greater than low curvature coefficient and high Reynolds number, respectively. [ABSTRACT FROM AUTHOR]

In this study, a novel method for numerical simulation of drying is proposed and the process is optimized by Taguchi method. A 2D numerical solution is performed to analyze coupled heat and mass transfer occurring during drying of a rectangular moist object. The dryer section and the moist object are conjugately simulated where the coupled heat and mass transfer equations are solved together. The lattice Boltzmann method is employed to solve hydrodynamic, heat, and mass transfer equations. This study applied the Taguchi method to determine optimum conditions for drying so as to minimize the drying time and energy consumption. The control factors included temperature, air velocity, and thickness ratio (the moist object thickness to channel width). The following optimal conditions were obtained: temperature (T = 60 °C), velocity (V = 0.1 m/s), and thickness ratio (TR =0.1). The results of numerical solution are then compared to the measured data available in the literature, presenting a reasonable agreement. [ABSTRACT FROM AUTHOR]

Numerical simulations are used to analyze the thermal performance of turbulent flow inside heat exchanger tube fitted with cross-cut twisted tape with alternate axis (CCTA). The design parameters include the Reynolds number (5000

The present work investigates the natural convection of nanofluids in Rayleigh-Benard problem. New models, particularly some enhancement factors, are presented in this research to calculate the heat transfer characteristics of nanofluids around critical Rayleigh numbers, including the criteria in which the creation of Rayleigh-Benard and transition to turbulent flow occurs. The present models are compared with available models in the literature to reveal discrepancies of theoretical models in prediction of nanofluids heat transfer characteristics. This research is conducted for SiO2, Cu,CuO and Al2O3 as nanoparticle and water as the base fluid and discussed the SiO2-water nanofluid in more detail. Results indicate that the Nusselt number and convective heat transfer ratio are reduced for SiO2-water nanofluid for almost all volume fractions and as a result using SiO2 as nanoparticle into water (the base fluid) is not desired for a natural convection in Rayleigh-Benard problem. Moreover, the onset of natural convection is delayed due to the reduction in enhancement factor. [ABSTRACT FROM AUTHOR]

In this paper, an optimization procedure is presented by response surface method to optimize the temperature and velocity of drying air and thickness of the moist object inside the dryer. The optimization procedure is performed to determine the minimum drying time and energy consumption as responses. A two-dimensional (2D) numerical solution is accomplished to analyze coupled heat and mass transfer occurring during drying of an apple slice. The air flow and the moist object are solved conjugate, while the heat and mass transfer equations are solved coupled together using lattice Boltzmann method (LBM). Beside this, a sensitivity analysis is executed to calculate the sensitivity of the responses (drying time and energy consumption) to the control factors. Results reveal that the real optimized parameters for the minimum drying time and energy consumption are temperature (T = 80 °C), velocity (V = 0.10404 m/s), and thickness ratio (TR = 0.1). The results of numerical solution are compared to the experimental results, presenting a reasonable agreement. This analysis could be useful in food drying. [ABSTRACT FROM AUTHOR]

In the present work the effect of catalytic surface reaction on non-reactive bulk flow in micro-channel is investigated. The reaction surface is analyzed with assumption of constant wall temperature. To solve this problem, the energy, mole fraction and catalytic reaction equations are solved by trial and error process. The analysis show that most sensitive parameter is fuel conversion and the sensitivity of hydraulic diameter is more than longitude coordinates. [ABSTRACT FROM AUTHOR]

In flapping underwater vehicles the propulsive performance of harmonically sinusoidal heaving and pitching foil will be degraded by some awkward changes in effective angle of attack profile, as the Strouhal number increases. This paper surveys different angle of attack profiles (Sinusoidal, Square, Sawtooth and Cosine) and considers their thrust production ability. In the wide range of Strouhal numbers, thrust production of Square profile is considerable but it has a discontinuity in heave velocity profile, in which an infinite acceleration exists. This problem poses a significant defect in control of flapping foil. A novel profile function is proposed to omit sharp changes in heave velocity and acceleration. Furthermore, an optimum profile is found for different Strouhal numbers with respect to Square angle of attack profile. [ABSTRACT FROM AUTHOR]

The objective of this work is to estimate the accuracy of a predicted velocity profile which can be gained from experimental results, in comparison with the exact ones by the methodology of entropy generation. The analysis is concerned with the entropy generation rate in hydrodynamic, steady, laminar, and incompressible flow for Newtonian fluids in the insulated channels of arbitrary cross section. The entropy generation can be calculated from two local and overall techniques. Adaptation of the results of these techniques depends on the used velocity profile. Results express that in experimental works, whatever the values of local and overall entropy generation rates are close to each other, the results are more accuracy. In order to extent the subject, different geometries have been investigated. Also, the influence of geometry on the entropy generation rate is studied, and the distribution of volumetric local entropy generation rate for the selected geometries is drawn. [ABSTRACT FROM AUTHOR]

The effect of catalytic surface reaction on non-reactive flow in micro-channels is investigated. The hydraulic diameter of the channel is considered within the range of 0.2-1.2 mm, and the channel length is considered to be 5 mm. The whole length of the channel wall is coated with a catalyst. The sensitivity analysis shows that the effect of normalized hydraulic diameter is more than the normalized longitude coordinates in accordance with the existence of the large ratio of surface area to volume in the micro-channel. For validation of this model, the variation of fuel conversion is compared with the published experimental data and shows an acceptable agreement. [ABSTRACT FROM AUTHOR]

The transformation group theoretic approach is applied to perform an analysis of unsteady free convection flow over a vertical flat plate immersed in a power law fluid. The thermal boundary layer induced within a vertical semi-infinite layer of Boussinseq fluid. The system of governing partial differential equations with boundary conditions reduces to a system of ordinary differential equations with appropriate boundary conditions via two-parameter group theory. The obtained ordinary differential equations are solved numerically for velocity and temperature using the fourth order Runge-Kutta and shooting method. The effect of Prandtl number and viscosity index (n) on the thermal boundary-layer, velocity boundary-layer, local Nusselt number, and local skin-friction were studied. [ABSTRACT FROM AUTHOR]

The present work investigates an analytical study on the problem of laminar film condensation on a nanosphere. Due to the microscale interaction, the problem is analyzed by taking into account the effects of slip in velocity and Jump in temperature. A relation is derived for the liquid film thickness in the form of a nonlinear differential equation which is solved numerically using the fourth order Runge-Kutta method. Finally, the effect of velocity slip and temperature jump on different condensation parameters including the liquid film thickness, velocity and temperature profiles, Nusselt number, and liquid mass flow rate is discussed. It is found that the increase in the velocity slip and temperature jump results in a thinner liquid film and therefore increases the heat transfer coefficient. [ABSTRACT FROM AUTHOR]

A large portion of world's final energy consumption is employed in thermal form. The proper techniques can be used to improve the efficiencies of thermal energy systems and decrease the energy consumption. Phase change material (PCM) storage modules can be coupled with different thermal systems to improve their thermal efficiency. This paper reviews the real potentials of coupling PCM storage modules to heat pipes and heat pumps in terms of energy saving and thermal energy management. The different systems suggested by researchers are described, and the main findings of the studies are provided. The advantages and disadvantages of these combined systems are discussed, and some suggestions for future studies are provided. The results show that heat pipes show great heat transfer ability and have good efficiency in improving heat transfer within PCMs. Moreover, heat pipes can be incorporated into PCMs to decrease the thermal resistance. The purpose of PCM coupled with heat pipe is to incorporate the large thermal conductivity of heat pipe with the large latent heat capacity of PCM. PCMs have ability to balance the unconformity between supply and demand in heat pumps and decrease the size of storage tank used in a heat pump module. [ABSTRACT FROM AUTHOR]

In this paper, a novel study on the heat transfer characteristics in a shell and tube heat exchanger with wavy cosine corrugated wall in structure of tube bundle is investigated experimentally. The optimization procedure is performed by means of response surface methodology in different wavy starting lengths (0 mm ≤ b ≤ 120 mm), hot water flow rates (7 L min−1 ≤ Qh ≤ 11 L min−1), cold water flow rates (11 L min−1 ≤ Qc ≤ 19 L min−1) and wavy wavelengths (0 mm ≤ λ ≤ 80 mm) to obtain maximum effectiveness and the overall heat transfer coefficient. An exergetic sustainability analysis has been done to show how exergy efficiency affects sustainability. The results show that the effectiveness and the overall heat transfer coefficient increase with the cold water flow rates. Additionally, enhancement of the wavy starting lengths decreases the heat exchanger effectiveness and the overall heat transfer coefficient. From sustainability point of view, the corrugated tube is more sustainable than smooth tube. [ABSTRACT FROM AUTHOR]

In this paper, the magnetic nanofluids and magnetic field are used to provide a coating around the wall of a channel. The magnetic field is induced by the direct current wire. Iron oxide is used as magnetic nanoparticles. A finite volume method is used to solve the Navier–Stokes equations, and the Eulerian–Lagrangian approach is employed to track the magnetic nanoparticles. The effects of magnetic strength, the position of current wire, and the diameter of magnetic nanoparticles on the trajectory of magnetic nanoparticles and coating efficiency are investigated by providing contours and diagrams. The results show that the length of coating decreases by about 55% with the increase in the particle diameter in the range of 500 nm to 1 μm. Further, the coating efficiency, defined as the ratio of the number of trapped particles on the wall to the number of injected particles at the inlet of the channel, improves by increasing the magnetic strength and decreasing the vertical position of the current wire. [ABSTRACT FROM AUTHOR]

This paper presents numerically an appropriate position of a porous insert to get a better thermohydraulic performance from a porous heat exchanger. The simulation is based on the Darcy-Brinkman-Forchheimer model in the porous field. Two-dimensional continuity, momentum, and energy equations with incompressible, laminar, steady assumptions have been solved using a finite volume approach. The analysis is performed for different values of porous layer thickness, length, and porosity at a fixed value of Reynolds number (Re = 100) and thermal conductivity ratio (Rc = 5). The results showed that there is about a 48% and 13% reduction in pressure drop and Nusselt number, respectively, by decreasing horizontal porous substrate thickness from 1 to 1/2 for δv = 1/3 at ε = 0.7. As a result, the pressure drop reduces considerably with a reasonable reduction in heat transfer rate by decreasing horizontal porous substrate thickness from 1 to 1/2. [ABSTRACT FROM AUTHOR]

In this paper, a new application is presented for a helical screw tape insert in a 3D tube. In this application, an eccentricity is created between the centrelines of helical screw tape and tube. Accordingly, the effects of this eccentricity on thermal-hydraulic performance and entropy generation are investigated numerically. A three-dimensional SSTk − ω turbulence model is applied to simulate this problem. All simulations are made for eight values of the eccentricity in the range of 0 to 3.5 and Reynolds numbers in the range of 5000 to 12,000. The calculated results showed that incorporating the helical screw tape near the tube wall (by increasing the eccentricity value) diverts the swirling flow from the core region towards the tube surface where high velocity flow impinges over the tube wall, hence extracting higher amount of thermal energy. Moreover, 42% and 237% increments are observed in the frictional and thermal entropy generations, respectively for an eccentricity in the range of 0 to 3.5. [ABSTRACT FROM AUTHOR]

This study investigates the effect of the addition of nanoclay (Cloisite 20A) on some mechanical properties, % relative brightness (ΔLrel) and total colour change (ΔEab) of high density polyethylene (HDPE)/pistachio shell flour (PSF) composites when exposed to accelerated weathering conditions. X-ray diffraction (XRD) patterns of samples containing 3 and 6 per hundred composite (phc) of nanoclay indicated partial exfoliation and intercalation. The tensile modulus and tensile strength of HDPE/PSF composites (without nanoclay) decreased when the exposure time increased to 1500 h, while the tensile modulus and tensile strength increased. For samples with nanoclay, ΔLrel and ΔEab increased upon accelerated weathering conditions up to 500 h, and thereafter remained constant. But results show that ΔLrel and ΔEab increased significantly upon accelerated weathering exposure in HDPE/PSF samples up to 1500 h. Scanning electron microscopy (SEM) results after 1500 h exposure to weathering condition showed signs of the presence of cracks in samples without nanoclay, unlike the samples with nanoclay. [ABSTRACT FROM AUTHOR]

In this paper, an optimization procedure is performed by response surface methodology to optimize the position and size of the partition inside a single slope solar still. The partition is installed separately at bottom surface and glass cover of the still to improve the performance. The optimization procedure is performed to determine the maximum Nusselt number as a response. Two-dimensional steady equations with laminar assumption have been solved using a finite volume approach. Analysis is performed for a fixed value of Rayleigh number. Beside this, a sensitivity analysis is performed to calculate the sensitivity of the response (Nusselt number) to the position and size of the partition. Results show that the real optimized parameters for the maximum normalized Nusselt number of bottom installed partition are X′ = 0.23 and Y′ = 0.18. These parameters for the the maximum normalized Nusselt number of top installed partition are X′ = 0.53 and Y′ = 0.56162. Also, the installation of partition leads to an increase in vortices number with smaller sizes. Smaller vortices provide sufficient pathways to heat exchange and increase the still efficiency. [ABSTRACT FROM AUTHOR]

This paper applies the particle image velocimetry (PIV) to measure the laminar boundary layer thickness of TiO 2 –water nanofluid free convection over the vertical and horizontal flat plates with constant heat flux. The results are presented for two values of heat flux strength equal to 3000 and 7000 w/m 2 . The effects of nanoparticles and heat flux strength on the boundary layer thickness and velocity profiles are investigated in details. Finally, a comparison is performed between the experimental, theoretical and numerical results for different conditions. The obtained results revealed that the velocity boundary layer decreases by adding the nanoparticles to the base fluid. These reductions, at ϕ = 0.1%, are in the vicinity of 7.5% and 5.2% for q ″ = 3000 and 7000 wm - 2 , respectively. Also, the maximum reductions in the vertical velocity component by adding the nanoparticles at ϕ = 0.1% are in the vicinity of 4% and 3.3% for q ″ = 3000 and 7000 wm - 2 , respectively. [ABSTRACT FROM AUTHOR]

Convective heat transfer of Al 2 O 3 –water nanofluid over an equilateral triangular obstacle with an optimization analysis is carried out to determine the optimum conditions for the maximum heat transfer rate and the minimum drag coefficient. Orientations of the obstacle, values of the solid volume fraction, and Reynolds number are selected as the input parameters. The analysis is performed according to the Response Surface Methodology. The response surface equation is obtained using the design of the experiments features. Two-dimensional unsteady equations with the relevant boundary conditions have been solved using finite volume method. Three different orientations of the triangular obstacle are defined for the optimization procedure. The computational simulations are done for different Reynolds numbers ( 1 ≤ Re ≤ 180 ), solid volume fractions ( 0 ≤ φ ≤ 0.05 ) and orientations of the triangular obstacle ( 0 ° ≤ θ ≤ 60 ° ). Also, a comparison is performed between the results of CFD analysis and Response Surface Methodology. It is found that the minimum drag coefficient is occurred at θ = 35.13°, Re = 97.6 and φ = 0.01 and the maximum Nusselt number is found at θ = 8.49°, Re = 180 and φ = 0.05. [ABSTRACT FROM AUTHOR]

In this research, for the first time, the effects were investigated of nanoclay as a secondary reinforcement, titanium dioxide (TiO2) and hindered amine light stabilizer (HALS) as UV stabilizers on some properties of high density polyethylene (HDPE)/pistachio shell flour (PSF) composite as the new wood plastic composite (WPC). WPCs of HDPE/PSF with different levels of nanoclay (Cloisite 20A), TiO2 and HALS were prepared. Some properties were investigated before exposure to weathering conditions. Design of experiments (DOE) was carried out to find the best formulation and decrease the number of tests. WPC granules were prepared by melt-mixing method using a twin screw extruder, and then moulded using an injection moulding machine to prepare samples. The results of X-ray diffractometry (XRD) indicated partial exfoliation and intercalation of samples containing 3 and 6 per hundred composite (phc) of nanoclay. The tensile strength and modulus of HDPE/PSF samples containing 3 and 6 phc nanoclay showed 20% increase compared to samples without nanoclay. The presence of TiO2 and HALS in the formulation did not have a significant effect on tensile properties. The nanoclay presence in HDPE/ PSF formulation improved the water absorption resistance. [ABSTRACT FROM AUTHOR]

In this article we intend to find the optimal shape of a nozzle respecting to some given target flow fields including viscosity effect. Via an approach based on measure theory which is not an iterative method and need not to any initial guess, each shape optimization problems are solved and consequently each geometry of the nozzle corresponding to prescribed flow fields is determined. Analyzing several case studies make us to confident on the use of the presented approach, because the obtained results give entirely the same as what we expect physically. [ABSTRACT FROM AUTHOR]

In this study, a fluid-structure interaction (FSI) simulation of the blood flow in the femoral artery with a small occlusion is presented. For a more accurate simulation of the real conditions, computerized tomography (CT) scan was used to obtain a 3-D model of leg blood vessels, while the vessel was modeled as an isotropic elastic wall. By assuming a heartbeat period of 0.5 s, the inlet condition was considered as a time-dependent pulse using a non-Newtonian flow model. Blood flow was assumed nonlinear and incompressible, and Carreau model was used for blood rheological model. By considering unstable blood flow at the inlet, the involved hemodynamic parameters are velocity profile, vortices shapes, pressure drop, and streamlines. Furthermore, to determine the relationship between flow geometry and the vascular wall, wall shear stress (WSS) was calculated. By taking the real geometry of the vessel and fluidity of blood into account, comparison of computational results indicated a significant difference in velocity distribution and shear stress depending on whether the fluid-structure interaction is considered Newtonian or non-Newtonian. The results showed that employing Newtonian models for the blood flow does not lead to promising results at occluded areas and beyond them. [ABSTRACT FROM AUTHOR]

In this paper is introduced a new type of generalization of metric spaces called Sb metric space. For this new kind of spaces it has been proved a common fixed point theorem for four mappings which satisfy generalized contractive condition. We also present example to confirm our theorem. [ABSTRACT FROM AUTHOR]

The activity and toxicity of oral etoposide in women with recurrent ovarian cancer are described from a case series of women who had measurable disease. All patients had had previous platinum-based chemotherapy. Etoposide was given as 50 mg/day for 21 days every 4 weeks until there was progression of the disease or prohibitive toxicity. Twelve patients were enrolled into this study. Ten patients received a total of 48 cycles of etoposide; the median number of cycles was 4 (range 1 - 11). There were two partial responses (20%; 95% CI, 0 - 45%). The responses lasted 3.5 and 6 months. Median progression-free interval (PFI) was 7.5 months (range 5.5 - 11), and median survival time was 8.5 months (range 1.2 - 21.5). The main haematological toxicity was leukopenia and no treatment-related death occurred. Although etoposide appears to exhibit activity in recurrent ovarian cancer, response and survival durations are short, with a high rate of complications. [ABSTRACT FROM AUTHOR]