Effects of spaced retrieval on memory and quality of life in older adults with probable Alzheimer\u27s disease

This study was designed to explore the effects of spaced-retrieval training on memory and quality of life in older adults with probable Alzheimer’s disease. A total nineteen older adults with probable Alzheimer’s disease (AD) participated in these experiments. Experiment one was designed to determine whether the spacing effect is contributing to the success of the spaced-retrieval intervention. Participants were trained to recall a name-face association using either the adjusted spaced-retrieval method or a fixed interval retrieval method. The results showed a more consistent performance profile for the spaced retrieval group in comparison to the fixed interval group, providing evidence that the spacing effect is contributing to the gains in memory associated with spaced retrieval. Experiment two explored the effect of supplemental training sessions, ‘booster sessions’, on long term retention of the name-face association at a six month retest after the initial spaced retrieval training. The findings show booster sessions enhanced the long term effectiveness of the intervention, particularly during the first retest session. Experiment three examined the flexibility of the spaced retrieval method for use with familiar name-face associations. Subjects were trained on a familiar name-face association using the same methodology previously used for a non-familiar name-face association. Results indicated that the intervention could be useful in training familiar name-face associations. In addition to these specific experiments, quality of life was measured for all participants in each experiment prior to and after receiving the spaced retrieval intervention. Results provide preliminary evidence of a link between performance on the spaced retrieval task and improved rankings of quality of life

Experimental study of simulated micro-gravity vapor-liquid flow regimes

Space missions in the near future will require power plants and cooling systems to operate in space. Such systems will often incorporate two-phase (vapor-liquid) heat transfer loops. Heat transfer processes such as boiling and condensation involve two-phase flow and are gravity dependent. Such unit operations would, therefore, be expected to behave differently in a micro-gravitational ( micro-g ) environment. In this study, a unique approach to study the flow patterns of vapor-liquid flow on earth is presented. Simulation of a micro-g vapor-liquid flow on earth is accomplished by the use of two immiscible liquids of equal density. This equal density two-liquid system makes the buoyancy forces approach zero which is the case for real vapor-liquid flow in micro-g conditions. Water and properly selected oils are used in the experiments. In simulating micro-g vapor-liquid flow, the oil which is more viscous and more wettable liquid represents the liquid phase and water (less viscous and less wettable with respect to waxed tube surface) corresponds to the vapor phase. The experiments are carried out in a horizontal pyrex glass tube (6.1 m long and 2.54 cm ID). Data are obtained for five different fluid systems to study the effect of viscosity ratio, interfacial tension, and wettability of two fluids on flow regime boundary lines. Comparison of the simulated versus actual micro-g vapor-liquid flow regime data indicates the validity of this simulation approach. The experimental results are also compared against Taitel-Dukler and Weisman et al. model predictions under micro-g conditions. A flow regime map for vapor-liquid flow in a micro-g environment is developed for usage in designing two-phase systems in space applications. The effect of gravity on nucleate boiling is also considered. The static and dynamic forces acting on a growing vapor bubble on heating surface are evaluated and how their interaction causes the bubble to detach from the surface is presented. By using a force balance, the bubble departure radius is calculated and compared with experimental measurements from literature under micro-g conditions

Laser diagnostics for characterization of sprays formed by a collapsing non-equilibrium bubble

In this paper, we investigate the use of laser diagnostic tools for in-plane imaging of bubble induced spray using a laser sheet and Mie scattering technique. A perspex plate of thickness 10 mm with a hole of diameter 1 mm in the center is placed in the middle of a glass tank filled with water such that the top surface of the plate coincides with the water surface. A bubble is created just below the hole using a low-voltage spark circuit such that it expands against the hole. This leads to the formation of two jets which impact leading to a spray and break-up into droplets. The spray evolution is observed using a laser sheet directed in a plane through the center of the hole. The illuminated plane is imaged using a high-speed camera based on the Mie scattering from glass beads suspended in the liquid. Results show that Mie scattering technique has potential in studying bubble-induced sprays with applications such as in fuel sprays, drug-delivery etc, and also for validation of numerical codes. We present results from our ongoing experiments in this paper

Hydrodynamic Scale-Up of Circulating Fluidized Beds

A general procedure that can be used to scale up circulating fluidized beds is presented. It consists of developing a mathematical model in conjunction with measuring 1) the radial dispersion coefficient (Dr) using gas tracers, 2) the radial solids velocity profile using a Pitot tube and 3) the radial distribution of solids density (1 - ε) using an optical probe. If the resulting information is obtained in a riser 200 mm or greater in diameter, it can be used in conjunction with the mathematical model for scale-up

Detection of Gas Bypassing due to Jet Streaming in Deep Fluidized Beds of Group A Particles

Tests were conducted in deep fluidized beds with and without gas bypassing to develop a technique to detect jet streaming. By placing differential pressure (DP) transmitters across a middle section of the fluidized bed, it was found that jet streaming can be detected by analyzing the DP fluctuations

Erosion in Second Stage Cyclones: Effects of Cyclone Length and Outlet Gas Velocity

Severe erosion in the lower cone and in the upper dipleg of second stage cyclones have been observed in commercial cyclones. The main objective of this study is to shed light on the mechanism by which this erosion takes place, and how different design and operating parameters affect the erosion. Experimental data on how parameters such as the cyclone length-to diameter ratio (L/D), inlet solids loading and gas outlet velocity affect second stage cyclone erosion are presented. The outlet gas velocity was varied by changing the size of the vortex tube diameter. The effect of a vortex stabilizer on cyclone cone erosion is also discussed

Hydrodynamics of high velocity circulating fluidized bed risers

Fluid catalytic cracking risers operate at solids fluxes of 400 to 1400 kg/s.m2 and gas velocities of 15 to 20 m/s. However, most literature studies are for low gas velocities (\u3c 10 m/s) and modest solids circulation rates (\u3c 200 kg/m2s). Circulating fluidized bed (FCC) risers were found to consist of a top dilute region and a relatively dense region near the bottom. The top region has a dilute core of rapidly upflowing solids surrounded by a descending dense annulus. The bottom zone also has a core-annular flow structure, but with little or no net downflow of solids in the annulus. This paper discusses measurements from three CFB risers 15, 22, and 24 m in height, all 0.3 m in diameter, for FCC catalyst particles at gas velocities between 12 and 16 m/s and solids fluxes of 70 to 700 kg/s.m2. The measurements were total riser pressure, axial pressure gradient profiles and local solids flux. The extraction tube technique was used the solids flux measurement. The apparent density decreased exponentially with increasing height at low solids fluxes and a dense lower region formed as the solids flux was increased. Its height reached nearly half of one of the risers’ height at the highest solids flux. Three types of radial solids flux profiles were obtained; nearly flat, parabolic with maxima in the core as well as bell shaped profiles with highest fluxes near the riser walls. The net solids flow direction at all locations was upward

Invited: High-level design methods for hardware security: Is it the right choice?

Due to the globalization of the electronics supply chain, hardware engineers are increasingly interested in modifying their chip designs to protect their intellectual property (IP) or the privacy of the final users. However, the integration of state-of-the-art solutions for hardware and hardware-assisted security is not fully automated, requiring the amendment of stable tools and industrial toolchains. This significantly limits the application in industrial designs, potentially affecting the security of the resulting chips. We discuss how existing solutions can be adapted to implement security features at higher levels of abstractions (during high-level synthesis or directly at the register-transfer level) and complement current industrial design and verification flows. Our modular framework allows designers to compose these solutions and create additional protection layers

Is There a Role for Treating Inflammation in Moyamoya Disease?: A Review of Histopathology, Genetics, and Signaling Cascades

Moyamoya disease is a slowly progressing steno-occlusive condition affecting the cerebrovasculature. Affecting the terminal internal carotid arteries (ICA) and there branches, bilaterally, a resulting in a fine vascular network in the base of the brain to allow for compensation of the stenosed vessels. While there is obvious evidence of the involvement of inflammatory proteins in the condition, this has historically not been acknowledged as a causal factor. Here we describe the fundamental histopathology, genetics, and signaling cascades involved in moyamoya and debate whether these factors can be linked as causal factor for the condition or whether they are simply a secondary result of the ischemia described in the condition. A particular focus has been placed on the multitude of signaling cascades linked to the condition as these are viewed as having the greatest therapeutic potential. As such we hope to draw some novel insight into potential diagnostic and therapeutic inflammatory targets in the condition