Adjoint operator approach to shape design for internal incompressible flows

The problem of determining the profile of a channel or duct that provides the maximum static pressure rise is solved. Incompressible, laminar flow governed by the steady state Navier-Stokes equations is assumed. Recent advances in computational resources and algorithms have made it possible to solve the direct problem of determining such a flow through a body of known geometry. It is possible to obtain a set of adjoint equations, the solution to which permits the calculation of the direction and relative magnitude of change in the diffuser profile that leads to a higher pressure rise. The solution to the adjoint problem can be shown to represent an artificially constructed flow. This interpretation provides a means to construct numerical solutions to the adjoint equations that do not compromise the fully viscous nature of the problem. The algorithmic and computational aspects of solving the adjoint equations are addressed. The form of these set of equations is similar but not identical to the Navier-Stokes equations. In particular some issues related to boundary conditions and stability are discussed

Clay/Biopolymer Composite and Electrorheological Properties

The combination of clays with polymers having different characteristics opens a way to new composite materials showing novel properties. Electrorheological (ER) fluids show phase transition from a liquid to a solid-like state between the electrodes of a rheometer due to the interactions of polarized particles. Composite systems comprising biodegradable chitosan (CS) and natural bentonite (BNT) are important in ER applications. In this study, BNT/CS composites were synthesized by the in situ method. The structure and morphology of the synthesized composites were characterized using X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM) techniques. Thermal stability was observed to increase with the presence of BNT clay. Conductivity of the composites was found the suitable range for ER measurements. According to ER results, BNT/CS composites were found to be sensitive to external electric field strength, exhibiting a typical shear thinning non-Newtonian viscoelastic behavior

Dual Response of Materials under Electric and Magnetic Fields

The electrorheological (ER) effect is known as the change in the rheological behaviors of ER fluids under applied electric field E. When an E is imposed, ER fluids show phase transition from a liquid to a solid-like state due to the interactions of polarized particles. This solid-like behavior of particles is due to the increasing viscosity of suspensions. ER materials belong to a family of controllable fluids. ER fluids are dispersions of solid particles in a hydrophobic insulating dispersion medium. These solid particles play a very important role in the ER activity of dispersions. As the dispersed phase, diverse materials such as polymer blends, gels, biodegradable materials, clays, graphene oxide, hybrid nanocomposites, copolymers, ionic liquids, and conducting polymers have been proposed. In the magnetorheological fluids, this control is provided with magnetic field. Various magnetic particles such as carbonyl iron and iron oxides have been suggested as MR material. The combined effect of magnetic and electric field produces intensified rheological changes in the suspensions. This synergic effect is termed as electromagnetorheological effect (EMR). The EMR effect provides a new strategy to control the rheological properties of dispersions

Capitalism, patriarchy and identity women and capitalist industrialisation in Turkey : textile workers in Manisa.

SIGLEAvailable from British Library Document Supply Centre-DSC:DX201009 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Multiple Output Battery Charging Circuit for Bikers

Bikers want to charge their devices containing batteries (such as smart phones, bicycle headlight, head cameras), which they need in their daily lives, with the energy produced by their bicycles. A device capable of storing kinetic energy of bikers contributes to environment friendly electric power generation. This paper presents a multiple output battery charging circuit design for bikers. Proposed design consists of a dynamo capable of producing 12 V and it charges 2 × 4000 mAh storage batteries with a buck converter that produces an output voltage of 1.29 A 4.2 V. Li-ion batteries are the most suitable batteries for portable storage applications due to their compact size, light weight and long-life time features. 2 × 4000 mAh Li-ion batteries charge a 5 V 2000 mAh battery with a boost converter. Proposed method is simulated using MATLAB/Simulink. The simulation results are compared with the experimental results. The simulation and experimental results are in accordance with each other. A biker using the device suggested in the study will be able to ride an average of 2 hours a day and store the energy to fully charge the smart phone or bike headlight or head camera with 1 week of use

Tree-formed Verification Data for Trusted Platforms

The establishment of trust relationships to a computing platform relies on validation processes. Validation allows an external entity to build trust in the expected behaviour of the platform based on provided evidence of the platform's configuration. In a process like remote attestation, the 'trusted' platform submits verification data created during a start up process. These data consist of hardware-protected values of platform configuration registers, containing nested measurement values, e.g., hash values, of loaded or started components. Commonly, the register values are created in linear order by a hardware-secured operation. Fine-grained diagnosis of components, based on the linear order of verification data and associated measurement logs, is not optimal. We propose a method to use tree-formed verification data to validate a platform. Component measurement values represent leaves, and protected registers represent roots of a hash tree. We describe the basic mechanism of validating a platform using tree-formed measurement logs and root registers and show an logarithmic speed-up for the search of faults. Secure creation of a tree is possible using a limited number of hardware-protected registers and a single protected operation. In this way, the security of tree-formed verification data is maintained.Comment: 15 pages, 11 figures, v3: Reference added, v4: Revised, accepted for publication in Computers and Securit

The effect of dietary inclusion of meat and bone meal on the performance of laying hens at old age

The effect of the inclusion of meat and bone meal (MBM) in the diet of old laying hens on their egg production and the quality of their eggs was investigated. Meat and bone meal containing a high concentration of ash and a low concentration of crude protein was included at levels of 2.0, 4.0 and 6.0% in the diets and fed for 20 weeks. Forced moulted 84-week old laying hens (Brown-Nick) were divided randomly into four treatment groups of 120 hens each. The inclusion of 2.0% MBM to the layer diet increased hen-day egg production significantly, whereas inclusion in excess of 2.0% MBM had no additional beneficial effect on egg production. However, the inclusion of dietary MBM at all three levels depressed egg weight. There were no significant effects of dietary treatments on egg weight, feed intake and feed conversion ratio of the hens. The specific gravity of the eggs from hens fed the control diet was significantly lower than from those receiving the diets containing 2.0 and 4.0% MBM. The Haugh Unit value of eggs in the 6.0% MBM treatment was significantly higher than the other treatments. There were no significant effects of MBM inclusion on yolk colour score, yolk height, eggshell thickness, eggshell weight and eggshell strength. However, MBM inclusion in a diet had a significant beneficial effect on eggshell quality. The eggshell ratios of the 2.0, 4.0 and 6.0% MBM treatments were significantly higher than in the control diet, while the cracked/broken egg ratio was significantly lower. In conclusion, inclusion of MBM containing a high ash and low crude protein content to conventional maize-soya bean diet improved egg production performance of laying hens. The dicalcium phosphate level in the diet could also be reduced without any adverse effects on egg production and egg quality. Key Words: Meat and bone meal, Egg production, Egg quality, Laying hens SA Jnl Animal Sci Vol.34(1) 2004: 31-3