Superparamagnetic nanomagnetites modified with histidine and tyrosine

Magnetite nanoparticles coated with tyrosine and histidine were synthesized by in situ decomposition of the precursors–coordination compounds containing the aminoacids as ligands. All of the obtained compounds were characterized using infrared spectroscopy (FTIR), X-ray diffraction, Mössbauer spectroscopy, magnetic and thermal measurements. Data demonstrate the presence of the aminoacids chemisorbed on the surface of magnetite nanoparticles and their superparamagnetic character.     

Energy policy and European utilities’ strategy: Lessons from the liberalisation and privatisation of the energy sector in Romania

In the context of energy sector reforms pursued by Romanian government since 1990s, we compare and contrast the market outcomes of European utilities’ investment with the host government policy objectives. We begin with energy market reform in Romania and review governments’ efforts to attract foreign direct investment (FDI) and to gradually withdraw from the distribution and supply segments of electricity market. Subsequently, we illustrate the scope European utilities have had, market policy and design notwithstanding, for consolidating market power through regional dominance. We examine the extent to which these utilities have sought to enhance their positions through horizontal and vertical integration, counter to the EU plans for a competitive market structure. We find that the investments of European incumbents have not been resoundingly successful: although market entrance may have been justified on long-term strategic grounds, in the immediate term, segments acquired through competitive auctions have yielded modest regulated returns. Finally, we discuss the extent to which policy makers have achieved their goals. Although the short-term benefits of a competitive market structure have reached some consumers, a renewed interest in promoting ‘national champions’ reflect frustration with market mechanisms as a means of ensuring long-term strategic investments in the sector.     

An Implementation Approach of the IEEE 1149.1 for the Routing Test of a VLSI Massively Parallel Architecture

This paper presents an implementation approach for the test of routers in a fine grain massively parallel architecture. First, an ad hoc test technique which diffuses test messages router by router is analyzed. Even though the technique does not add hardware, it is shown inefficient and not applicable due to practical constraints such as the limited number of pins of the chip implementing the machine. Based on a hierarchical implementation of the IEEE 1149.1 standard, two approaches are proposed and compared in terms of the area overhead, the overall test time and the flexibility in applying tests and diagnosing the routers inside the machine. The basic idea for both approaches is to construct groups of basic cells which are driven by the same test block and compare their test results after the same test vectors are applied at each cell input. The two approaches differ in the granularity of a basic cell. The choice of an implementation approach is not trivial. It is shown that each approach presents better performance than the other, that is, the approach which allows better fault coverage and less test time requires more silicon and less diagnostic possibilities compared to the second approach.     

Silsesquioxane-based hybrid nanocomposites with methacrylate units containing titania and/or silver nanoparticles as antibacterial/antifungal coatings for monumental stones

The present paper reports on the evaluation of two silsesquioxane-based hybrid nanocomposites with methacrylate units containing titania and/or silver nanoparticles aimed as antibacterial coatings for monumental stones. Sol–gel reaction of titanium isopropoxide and/or 3-(trimethoxysilyl)propyl methacrylate, in the presence of silver nitrate and a primary amine surfactant, yielded new types of hybrid nanocomposites with high antibacterial/antifungal efficacy. Different polymer behaviours regarding a frequently used monumental stone originating from Romania were evidenced through Fourier-transform infrared (FTIR) spectroscopy and powder X-ray diffraction (PXRD) technique. Conclusions regarding the stones acid-resistant character and lower influence of salt weathering on its durability, as well as a better protective coating containing titania units were revealed.     

Network search method in the design of extreme ultraviolet lithographic objectives

The merit function space of mirror system for extreme ultraviolet (EUV) lithography is studied. Local minima situated in the multidimensional optical merit function space are connected via links that contain saddle points and form a network. We present networks for EUV lithographic objective designs and discuss how these networks change when control parameters, such as aperture and field, are varied, and constraints are used to limit the variation domain of the variables. A good solution in a network, obtained with a limited number of variables, has been locally optimized with all variables to meet practical requirements.     

金刚石砂轮双端面磨削氧化铝陶瓷

本研究涉及双端面磨削技术应用于用两片陶瓷结合剂金刚石砂轮同时磨削圆柱形氧化铝陶瓷工件两个端面的技术评价。精细陶瓷(advanced ceramics),例如氧化铝(Al2O3),由于具有高的硬度、抗压强度、耐腐蚀性、导电性、磁导率和脆性而应用广泛。本试验为四因子试验,评价被磨工件的表面粗糙度Ra,采用重量法测定材料去除率,采用激光折射技术测定的平均比例系数来评价被磨工件平面度。本文的研究结果表明,双端面磨削可以在很短的加工时间内获得极高的表面光洁度、高的精度和高的磨除率。     

Materials Based on Quaternized Polysulfones with Potential Applications in Biomedical Field: Structure–Properties Relationship

Starting from the bactericidal properties of functionalized polysulfone (PSFQ) and due to its excellent biocompatibility, biodegradability, and performance in various field, cellulose acetate phthalate (CAP) and polyvinyl alcohol (PVA), as well as their blends (PSFQ/CAP and PSFQ/PVA), have been tested to evaluate their applicative potential in the biomedical field. In this context, because the polymer processing starts from the solution phase, in the first step, the rheological properties were followed in order to assess and control the structural parameters. The surface chemistry analysis, surface properties, and antimicrobial activity of the obtained materials were investigated in order to understand the relationship between the polymers’ structure–surface properties and organization form of materials (fibers and/or films), as important indicators for their future applications. Using the appropriate organization form of the polymers, the surface morphology and performance, including wettability and water permeation, were improved and controlled—these being the desired and needed properties for applications in the biomedical field. Additionally, after antimicrobial activity testing against different bacteria strains, the control of the inhibition mechanism for the analyzed microorganisms was highlighted, making it possible to choose the most efficient polymers/blends and, consequently, the efficiency as biomaterials in targeted applications.     

Tartarate precursors to CoxZn1−xGa2O4 spinel oxides

The Co_xZn_1−xGa₂O₄ spinels (x = 0.25, 0.5, 0.75, 1) were synthesized by a wet chemistry method–the precursor route via tartarate decomposition. The complex precursors have been characterized by IR, UV–Vis, magnetic measurements and luminescence spectroscopy. XRD, SEM, IR, UV–Vis and luminescence spectroscopy were used for the structural and morphological investigation of Co_xZn_1−xGa₂O₄ spinels; magnetic susceptibilities of the spinel were also measured. The X-ray diffraction patterns confirmed the formation of gallate spinel phase, Co_xZn_1−xGa₂O₄.     

Green Blends Based on Ionic Liquids with Improved Performance for Membrane Technology: Perspectives for Environmental Applications

Present research was directed towards the development of new high-performance and cost-effective polysulfone membranes (PSFQ) by introducing ionic liquids (ILs—Cyphos 101 IL and Aliquat 336) into their matrix. Variation of ILs was performed with the aim to find the one that brings new properties and improves the functionality and selectivity of PSFQ membranes in ultrafiltration processes. Based on the obtained results of the rheological study, we established the compatibility of compounds and optimal content of the used ILs, namely 3 wt% and 15 wt% Cyphos 101 IL and compositions varying between 3 and 15 wt % Aliquat 336. Results indicated that the ILs acted as plasticizers when they were added to the system, a helpful aspect in processing membranes used in water decontamination. The efficiency and performance of the membranes were evaluated by their use in the treatment of diclofenac (DCF)-containing waters. Membranes obtained from PSFQ/Aliquat 336 solution containing 15 wt% IL exhibited a 97% removal degree of DCF in the treatment process of 50 mL solution containing 3 mg/L DCF. The separation efficiency was kept constant for four filtration/cleaning cycles. The results indicated an improvement in membrane performance as the amount of IL in their structure increased, which confirms the potential for application in water treatment processes.     

Logical inference of Horn clauses in Petri net models

Petri net models for the Horn clause form of propositional logic and of first-order predicate logic are studied. A net model for logical inconsistency check is proposed. Algorithms for computing T-invariants of Petri net models of logical inference systems are investigated. The algorithms are based on the idea of resolution and exploit the presence of one-literal, pure-literal, and splitting clauses to lead to faster computation. Algorithms for computing T-invariants of high-level Petri net (HLPN) models of predicate logic are presented