Cytotoxicity versus antibacterial activity of some antiseptics in vitro

The relationship between endometriosis and infertility is observed frequently. Patients with both conditions require a conservative approach to their management. Since hormonal therapy is one of those approaches, we sought to compare the efficacy of Danazol and Gestrinone in 80 infertile patients (48 and 32, respectively). Therapy lasted 6 months in both treatment groups, and all patients studied had laboratory tests performed and were clinically evaluated and classified through laparoscopy before and after therapy. The improvement of symptoms and favorable follow-up were similar with both treatments. The reestablishment of menstrual patterns and fertility were also nearly alike in both groups. However, Gestrinone was associated with fewer secondary effects and is easier to administer than Danazol. We conclude that Gestrinone is a useful medication in the management of the infertile patient with endometriosis.     

Modelling computational requirements of mobile robotic systems using zones and processing windows

Mobile robotic systems must sense constraints imposed by a dynamically changing environment and predictably react to those changes in real-time. Complexity arises in mobile robotic systems because the computing platform travels through the environment with which the system is interacting. These systems have spatio-temporal requirements in the sense that correct behavior is defined in terms of both space and time. The focus of this paper is mobile robotic platforms that must sense their environment and avoid obstacles as they navigate from one point to another. We present a design and analysis methodology for these platforms that integrates spatio-temporal attributes with fixed priority real-time scheduling through the use of zone and processing window abstractions.     

Adding transverse normal stresses to layered shell finite elements for the analysis of composite structures

This work presents a formulation developed to add capabilities for representing the through thickness distribution of the transverse normal stresses, σ_z, in first and higher order shear deformable shell elements within a finite element (FE) scheme. The formulation is developed within a displacement based shear deformation shell theory. Using the differential equilibrium equations for two-dimensional elasticity and the interlayer stress and strain continuity requirements, special treatment is developed for the transverse normal stresses, which are thus represented by a continuous piecewise cubic function. The implementation of this formulation requires only C⁰ continuity of the displacement functions regardless of whether it is added to a first or a higher order shell element. This makes the transverse normal stress treatment applicable to the most popular bilinear isoparametric 4-noded quadrilateral shell elements.

To assess the performance of the present approach it is included in the formulation of a recently developed third order shear deformable shell finite element. The element is added to the element library of the general nonlinear explicit dynamic FE code DYNA3D. Some illustrative problems are solved and results are presented and compared to other theoretical and numerical results.     

Development and testing of a pressure probe for centerline static pressure measurement in supersonic nozzles and ejectors

This work describes the development and testing of a system for measuring static pressure along the axis of supersonic flow devices such as convergent–divergent nozzles or ejectors. The pressure probe consists of a capillary tube positioned at the ejector centerline. A hole is perforated perpendicularly on the wall of the thin tube to capture and deport the static pressure measurement to a piezoelectric sensor located at one extremity of the tube outside the ejector. The measurements obtained are compared with numerical results from computational fluid dynamics simulations and wall pressure measurements. The first tests demonstrate the good capability of the pressure probe to detect shocks occurring in the flow and to provide continuous axial distributions of the static pressure.     

A combined low temperature water heating system consisting of radiators and floor heating

Space heating load is decreasing in modern Finnish apartments due to lower U-values of the construction, tight envelopes and heat recovery from exhaust ventilation air. This makes it possible to develop a new combined low temperature water heating system with nominal supply/return water temperatures of 45 °C/35 °C. Such a system includes radiators in rooms and floor heating in bathrooms.In this study, the performance of an apartment building is determined by using dynamic simulation. The simulation results for the combined low temperature water heating system are compared with those for three conventional radiator and floor heating systems. The results show that the combined low temperature water heating system performs well and is able to maintain the zones within the required temperature levels. The thermal comfort analysis indicates that the drifts and ramps in operative temperature using the four studied heating systems are within the limits of Ashrae Standard 55-2004.Temperature measurements in a test room are carried out to find the vertical difference of air temperature using two methods: radiator heating and floor heating. These measurements indicate that there is only a small vertical temperature difference that would not produce any significant thermal discomfort.     

Going below the wet-bulb temperature by indirect evaporative cooling: Analysis using a modified ε-NTU method

The objective of this paper is to study a method to achieve sub-wet bulb temperature by indirect evaporative cooling of air (without using a vapor compression machine). For this purpose, an analytical model is developed based on the effectiveness-NTU method (ε-NTU). The main idea for achieving a sub-wet bulb temperature by indirect evaporative cooling of air is by indirectly pre-cooling the working air before it enters the wet passage. It is shown that a modified analytical model for indirect evaporative coolers could be based on the ε-NTU method for sensible heat exchangers when proper adjustments are made by redefining the potential gradients, transfer coefficient, heat capacity rate parameters and assuming a linear saturation temperature-enthalpy relation of air. This modified model is used to find the performance of a regenerative indirect evaporative cooler. The model results show very good agreement with results from experimental measurements and a numerical model.     

Three-dimensional computational micro-mechanical model for woven fabric composites

This work presents a computational material model for plain-woven fabric composite for use in finite element analysis. The material model utilizes the micro-mechanical approach and the homogenization technique. The micro-mechanical model consists of four sub-cells, however, because of the existing anti-symmetry only two sub-cells have to be homogenized for prediction of the elastic material properties. This makes the model computationally very efficient and suitable for large-scale finite element analysis. The model allows the warp and fill yarns not to be orthogonal in the plane of the composite ply. This gives the opportunity to model complex-shaped composite structures with different braid angles. General homogenization procedure is employed with two levels of property homogenization. The model is programmed in MATLAB software and the predicted material properties of different composite materials are compared and presented. The material model shows good capability to predict elastic material properties of composites and very good computational efficiency.     

Sandwich shell finite element for dynamic explicit analysis

The contribution of this paper consists of new development of transverse shear stresses through the thickness and finding an expression for the critical time step for explicit time integration of layered shells. This work presents the finite element (FE) formulation and implementation of a higher‐order shear deformable shell element for dynamic explicit analysis of composite and sandwich shells. The formulation is developed using a displacement‐based third‐order shear deformation shell theory. Using the differential equilibrium equations and the interlayer requirements, special treatment is developed for the transverse shear, resulting in a continuous, piecewise quartic distribution of the transverse shear stresses through the shell thickness. Expressions are developed for the critical time step of the explicit time integration for orthotropic homogeneous and layered shells based on the developed third‐order formulation. To assess the performance of the present shell element, it is implemented in the general non‐linear explicit dynamic FE code DYNA3D. Several problems are solved and results are presented and compared to other theoretical and numerical results. Copyright © 2002 John Wiley & Sons, Ltd.     

Photodegradation of phenol red in the presence of oxyhydroxide of Fe(III) (Goethite) under artificial and a natural light

The (α‐FeOOH) Goethite composite is a stable and an efficient catalyst in aqueous suspension under irradiation at 365 nm and by solar light. The photocatalytic activities of this composite were evaluated using Phenol Red (PR) dye (phenolsulfonphthalein class). In the dark, controlling factors, such as the pH and the adsorption of PR on Goethite surface were evaluated (before starting the photochemical experiments). It was found that the system PR‐Goethite present a small decrease in the main band of the dye (435 nm) which was explained by the low rate of adsorption of this dye on the Goethite. Also, we note that 40% of PR decolourisation was obtained after 200 min by the system PR‐Goethite‐hydrogen peroxide (H₂O₂) in dark due to the formation of ^?OH by thermal decomposition of H₂O₂ on the surface of Goethite. The effects of various experimental parameters, such as initial dye concentration, pH, photocatalyst amount, tert‐Butyl alcohol effect and H₂O₂ addition were investigated in the study of photodegradation of the dye. The results showed that the photodegradation of PR under UV‐A (365 nm) irradiation could be enhanced greatly in the presence of H₂O₂. Natural radiation tests (under sunlight) showed that degradation was faster comparing with that obtained using the artificial one at 365 nm. Studies of the mineralization using total organic carbon method under naturel light certify that this method, compatible with the environment, may be considered in the treatment of wastewater and generally in the process of removal of this kind of pollutant.