Effect of gamma irradiation on photoconductivity and photosensitivity of Si<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Sn<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> solid solutions

The results of studies of the structural feature and the effect of low-dose gamma irradiation (up to 105 rad) on the photoconductivity relaxation and the spectral photosensitivity of pSi-nSi_{1 − x} Sn _x (0 ≤ x ≤ 0.04) structures are described. It is shown that exposure to radiation leads to an increase in the relaxation time constant from 55 to 83 μs and an enhancement in the sensitivity of the structures in the short-wavelength emission spectrum, which is attributed to the radiation-stimulated gettering of crystal lattice defects localized in the near-boundaries regions between Si_{1 −x} Sn _x subcrystallites and Si_{1 − x} Sn _x -Sn and Si_{1 − x} Sn _x -SiO₂ phases.     

Fabrication and investigation of ultravialet Au-Zn<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Cd<Subscript>1–<Emphasis Type="Italic">x</Emphasis></Subscript>S-Mo-structures

For the first time fabricated and investigated the photovoltaic characteristics of Au-Zn _x Cd_1–x S-Mofilm structural injection photo detectors sensitive to narrow the ultraviolet region of the electromagnetic spectrum, based on polycrystalline Zn _x Cd_1–x S layers. It was found by adjusting the flow of ZnS and CdS coming to the surface Mo substrate can control the shape of the spectral sensitivity of the Au-Zn _x Cd_1–x S-Mo-film structural injection photo detectors. The results will allow to optimize the structure of photo detectors and solar cells based on polycrystalline thin film solar cells.     

Influence of gamma radiation on spectral photosensitivity of (Si<Subscript>2</Subscript>)<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript> (ZnSe)<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> solid solution

Increase of the photosensitivity of the pSi-n(Si₂)_{1 ? x} (ZnSe) _x (0 ≤ x ≤ 0.01) structure exposed to gamma radiation with photon energy E _ph ≥ 2.3 eV has been demonstrated. It is shown that irradiation with dose up to 10⁴ rad raises and radiation with dose up to 10⁵ rad reduces the forward current of the pSi-n(Si₂)_{1 ? x} (ZnSe) _x structure.     

The composition dependence of the effective thickness of the base layer in Al<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Ga<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>P/GaP heterophotoconverters

The dependence between the composition of Al _x Ga_{1 − x} P heterophotoconverters and the effective thickness of their base layers was established. An empirical formula to estimate the effective thickness of a base layer as a function of the composition of solid-state solution (0 ≤ x ≤ 0.8) was proposed.     

Output Feedback Robust <Emphasis Type="Italic">H</Emphasis>∞ Control with <Emphasis Type="Italic">D</Emphasis>-Stability and Variance Constraints: Parametrization Approach

In this paper, we study the problem of robust H controller design for uncertain continuous-time systems with variance and D-stability constraints. The parameter uncertainties are allowed to be unstructured but norm-bounded. The aim of this problem is the design of an output feedback controller such that, for all admissible uncertainties, the closed-loop poles be placed within a specified disk, the H norm bound constraint on the disturbance rejection attenuation be guaranteed, and the steady-state variance for each state of the closed-loop system be no more than the prescribed individual upper bound, simultaneously. A parametric design method is exploited to solve the problem addressed. Sufficient conditions for the existence of the desired controllers are derived by using the generalized inverse theory. The analytical expression of the set of desired controllers is also presented. It is shown that the obtained results can be readily extended to the dynamic output feedback case and the discrete-time case.2000 Mathematics Subject Classification. 93E15, 93B36, 93B55.This work was partially supported by the EPSRC under Grant GR/S27658/01, the Nuffield Foundation under Grant NAL/00630/G, and the Alexander von Humboldt Foundation of Germany.     

On Symmetries in Time Optimal Control,Sub-Riemannian Geometries,and the <Emphasis Type="Italic">K</Emphasis>−<Emphasis Type="Italic">P</Emphasis> Problem

The goal of this paper is to describe a method to solve a class of time optimal control problems which are equivalent to finding the sub-Riemannian minimizing geodesics on a manifold M. In particular, we assume that the manifold M is acted upon by a group G which is a symmetry group for the dynamics. The action of G on M is proper but not necessarily free. As a consequence, the orbit space M/G is not necessarily a manifold but it presents the more general structure of a stratified space. The main ingredients of the method are a reduction of the problem to the orbit space M/G and an analysis of the reachable sets on this space. We give general results relating the stratified structure of the orbit space, and its decomposition into orbit types, with the optimal synthesis. We consider in more detail the case of the so-called K?P problem where the manifold M is itself a Lie group and the group G is determined by a Cartan decomposition of M. In this case, the geodesics can be explicitly calculated and are analytic. As an illustration, we apply our method and results to the complete optimal synthesis on S O(3).     

On the possibility of applying <Emphasis Type="Italic">n</Emphasis>/(3C-SiC)–<Emphasis Type="Italic">p</Emphasis>/C<Subscript>DIAMOND</Subscript> white glow heterostructures with improved parameters in illumination systems with power consumption from solar radiation

The voltage-current characteristics and electroluminescence of a light-emitting-diode (LED) n/(3C-SiC)–p/ C_DIAMOND heterostructure with white glow without phosphor created on the basis of diamond film grown by the CVD method on n/(3C-SiC) substrates with a doped level of (5–8) × 10¹⁷ cm^–3 are considered It is shown the possibility to improve the characteristics of created LED structures by their irradiation with a flux of high-energy (5 MeV) electrons of a certain dose and heat treatment.     

Adjoint Orbits of <Emphasis Type="Italic">sl</Emphasis>(2, ℝ) on Real Simple Lie Algebras and Controllability

This paper shows that for any Lie group G whose Lie algebra L is the split real form of a complex simple Lie algebra, and for any arbitrary root α, there exists a Cartan decomposition of L, related to α, which characterizes some controllability properties by using the adjoint orbits of sl(2, ?). For a class of invariant control systems evolving on G, it is proved that the necessary full rank condition for controllability is also sufficient.     

Approximate Controllability of Fractional Semilinear Stochastic System of Order <Emphasis Type="Italic">α</Emphasis>∈ (1,2]

A family of dynamical control systems described by nonlinear fractional of order (1,2] stochastic differential equations in L _p spaces is considered. We discussed the approximate controllability of stochastic semilinear fractional control system of order α∈(1,2] under the assumption that the corresponding linear system is approximately controllable. A new set of sufficient conditions for approximate controllability of system are obtained by the theory of strongly continuous α-order cosine family, fixed point theorem, and stochastic analysis techniques. At the end, an example is given to illustrate the theory.     

Properties of tandem-junction heterophotoconverters with GaAs <Emphasis Type="Italic">p–n</Emphasis> junctions under exposure by bilaterally concentrated sunlight

Properties of GaAs/Al_xGa_1–xAs heterophotoconverters fabricated on two sides of monocrystal plates from GaP and GaAs under lighting conditions by V-shaped concentrators are described. It it found that, owing to the increased transparency of the photoconverter structure with respect to thermal photons and comparatively low GaP thermal resistance, the temperature increment of the p–n junctions and relative losses of the electrical power are notably lower than for photoconverters of the same structure on the basis of GaAs.     

An <Emphasis Type="Italic">ex post</Emphasis> criticism,based on stakeholders’ preferences,of a residential sector’s energy master plan: the case study of the Sicilian region

Energy master plans are important tools for an effective and sustainable land governance. On the other hand, the stakeholder role in setting priorities for planning energy interventions is dramatically increasing, also in the light of recently issued European directives. The priorities of energy-saving measures of the Sicilian energy and environmental master plan were originally established with the application of typical economic indicators (the cost of saved energy and the cost of avoided pollutant emissions). During the prioritization process, there was a minor contribution from stakeholders who were not directly involved in the priority-setting process but were only asked to express their opinions according to the in-force regulations. Based on more active stakeholder involvement in hierarchizing a given set of actions, as required by the recently issued directives, the University of Palermo, which participated in the development of this master plan, assessed an ex post evaluation of these established economy-based priorities, by means of the application of a multi-criteria decision analysis (MCDA) tool. The resulting changed priorities, which lead to a better policy allocation of the regional budget for energy efficiency in the building sector, confirm the preeminent role played by the stakeholders in the development of energy plans, further supported by a sensitivity analysis.     

Response to: “Evaluating energy efficiency policy: understanding the ‘energy policy epistemology’ may explain the lack of demand for randomized controlled trials,” by Adam Cooper, <Emphasis Type="Italic">Energy Efficiency</Emphasis>, published online 26 January 2018

In January 2018, Adam Cooper (Energy Efficiency, 2018) published a paper that principally responds to a paper by Vine et al. (Energy Efficiency, 7, 627–640, 2014) that makes the case for promoting greater use of experimental research designs, such as randomized controlled trials (RCTs), in the evaluation of energy efficiency policy. Cooper focuses on the barriers that public policy administrators face—arguing that there are alternative, rational reasons why RCTs are not commonly used in energy policy, providing an overlapping but somewhat different “energy policy epistemology” than in Vine (2014).     

Is it possible to carry out impact ionization in the narrow energy gap of <Emphasis Type=Italic>p-p,n-n</Emphasis> heterojunctions and increase the efficiency of thin-film solar cells?

We try to justify the idea that it is possible to implement impact ionization and generate additional electron-hole pairs in the narrow energy-gap layer by accelerating the high energy-gap photoelectrons by the field of a p-p, n-n heterojunction barrier and by increasing the efficiency of thin-film solar cells. We investigate whether impact ionization in the GaSb layer of a p-CdTe-p-GaSb heterojunction is possible and whether it is possible to increase the efficiency of a CdTe solar cell up to 50%.     

Questions of Simplifying the Methods of Testing Photoconverters Based on Cu(In,Ga)Se<Subscript>2</Subscript>. Part 1: A Basis for Mathematical Modeling of the Current–Voltage Characteristics

An analysis of possible errors of laboratory studies of current–voltage (I–V) characteristics for solar cells based on Cu(In,Ga)Se₂ (CIGS) using different lamps is provided, and the possibility of simplifying the procedure of testing the cells and panels by calculations and modeling is presented. Formulas are presented to develop mathematical models of the correlation between the quantum efficiency and the spectrum of the used lamp to obtain (I–V) characteristics of solar cells based on CIGS, which simplifies the testing procedure and data collection.