Low-Energy Laser-Driven Ultrashort Pulsed Electron Beam Irradiation-Induced Immune Response in Rats

The development of new laser-driven electron linear accelerators, providing unique ultrashort pulsed electron beams (UPEBs) with low repetition rates, opens new opportunities for radiotherapy and new fronts for radiobiological research in general. Considering the growing interest in the application of UPEBs in radiation biology and medicine, the aim of this study was to reveal the changes in immune system in response to low-energy laser-driven UPEB whole-body irradiation in rodents. Forty male albino Wistar rats were exposed to laser-driven UPEB irradiation, after which different immunological parameters were studied on the 1st, 3rd, 7th, 14th, and 28th day after irradiation. According to the results, this type of irradiation induces alterations in the rat immune system, particularly by increasing the production of pro- and anti-inflammatory cytokines and elevating the DNA damage rate. Moreover, such an immune response reaches its maximal levels on the third day after laser-driven UPEB whole-body irradiation, showing partial recovery on subsequent days with a total recovery on the 28th day. The results of this study provide valuable insight into the effect of laser-driven UPEB whole-body irradiation on the immune system of the animals and support further animal experiments on the role of this novel type of irradiation.     

Nonlinear robust control and minimax team problems

The problem of robust stabilization of a linear system leads to the classical ℋ︁_∞ control problem. The same analysis applied to a nonlinear system leads to the problem of ensuring via output feedback that a nonlinear operator be Lipshitz continuous, with a prescribed Lipshitz modulus. We show that, in the same way as the ℋ︁_∞ control problem is equivalent to a minimax control problem, the Lipshitz modulus control problem can be approached via a minimax team decision problem. This motivates us to re-visit a class of the so-called ‘static’ team decision problems for nonlinear dynamical control systems. Because of the ‘static’ character, signaling plays no role in that case, which is important for the equivalence with the Lipshitz modulus control problem. We show that under some conditions, a certainty equivalence principle applies that yields a practical solution to the team problem at hand. To reach that conclusion we must first investigate a ‘partial team’ problem where one of the team members has all the information. Copyright © 1999 John Wiley & Sons, Ltd.     

Carbon-13 assignments of EPDM/PP atactic blends by DEPT and HETCOR

The structure of the elastomeric ethylene–propylene–diene terpolymer/atactic polypropylene (EPDM/PPA) blends were assigned by NMR using DEPT (distortionless enhancement by polarization transfer) and HETCOR (heteronuclear correlation) sequences. These methods were carried out to elucidate solid-state ¹³C-NMR assignments of polymeric blends. © 1996 John Wiley & Sons, Inc.     

A new way to define better improvement options of existing buildings for energy saving

This work proposes a new methodology that is based on the ISO 13790 standard and the Monte Carlo method, which helps obtain the probability density function of the energy consumption in real buildings. The energy consumption under different improvement processes for each building was modelled considering variables such as thermal inertia, number of air changes and number of occupants. Some types of modifications, which are common and basic, were found to exert a clear effect over building energy consumption but these were not exactly defined by recommendations of most of the standards. Its effect was mostly due to the two parameters – the number of occupants and the number of air changes. These results should be considered in future during development of new standards for the purpose of defining the optimal amount of building energy consumption.     

Behavior of the refractive index of lithium disilicate glass ceramic processed at high pressure and high temperature

The aim of this work was to investigate the effect of high pressure and high temperature on the refractive index of lithium disilicate glass ceramic with the stoichiometric composition Li₂O·2SiO₂ (LS₂). A first group of monolithic LS₂ glass samples were processed at 2.5 GPa, 4 GPa and 7.7 GPa at room temperature and a second group was submitted to high pressure and, simultaneously, to heat treatments for nucleation and growth of the crystalline phases. For comparison, samples submitted to the same heat treatments at 1 atm were also investigated. The refractive index of the samples was obtained by spectral ellipsometry and the results were clearly dependent on the particular pressure and temperature conditions. The crystallization of the samples was investigated by X-ray diffraction. For the samples processed under high temperature at 1 atm and at 2.5 GPa a fraction of the originally amorphous glass was transformed to a monoclinic phase of lithium disilicate. For the samples processed under high temperature and at 4 GPa, a large fraction of the originally amorphous glass transformed to an orthorhombic phase while, at 7.7 GPa, it was observed the formation of lithium metasilicate.     

Dynamic inversion for multivariable non-affine-in-control systems via time-scale separation

This paper presents a tracking design methodology applicable to multivariable non-affine-in-control systems. The main focus is on solving the tracking problem for non-linear systems whose dynamics depend non-linearly on the control input. The latter is designed to be faster than the main system dynamics. Using singular perturbation theory along with the Lyapunov stability theorems, it is shown that the proposed controller approximates an unknown dynamic inversion based solution with bounded errors, provides closed-loop stability, and solves the tracking problem with bounded errors. Simulations illustrate the theoretical results.     

Effect of high pressure and high temperature on the mechanical behavior of diamond coated WC-Co

Polycrystalline diamond films were grown on WC-Co substrates by microwave assisted chemical vapor deposition using a gas mixture of hydrogen, oxygen and methane. The diamond coated WC-Co substrates were processed at high pressure (7.7 GPa) and high temperature (1000 °C) and their mechanical behavior was investigated by hardness instrumented testing before and after the high-pressure/high-temperature (HPHT) processing. The results indicated the diamond films became less friable after the HPHT processing, probably due to the infiltration of Co from the substrate. This conclusion was corroborated by corrosion tests performed with the samples before and after the HPHT processing.     

Tenure preference and housing strategy: An exploration of Pakistani experiences

There is an increasing literature on the exclusion of and difficulties faced by minority ethnic communities in a range of areas, of which housing is one of the most important. But there is relatively little good, recent, qualitative material available, which explores the process of decision‐making—including decisions regarding housing—within minority ethnic families. A missing element, therefore, is the study of action by householders and consequently, the realisation (or otherwise) of preferences and the cumulative results of actions in facilitating or restricting choice. The present paper reports on a small‐scale research study of Pakistani housing preferences in Glasgow, whose aim was to develop a life history interviewing technique, using a semi‐structured schedule, focusing on housing preferences, housing moves and experiences. Pakistani households are shown to experience continuing difficulties in funding and organising household moves. There are areas of Glasgow where families feel unsafe and there is a continuing problem of racial harassment. Neither the local authority nor housing associations are generally able to offer appropriate housing. The life history interviewing technique used allows an exploration of how households reached decisions on their housing and on how they indulged in ‘trade‐offs’ between different houses, areas or tenures. Thus our understanding of the role of agency in the development of patterns of housing and individual housing careers is developed.