Surface‐modified carbon black derived from used car tires as alternative,reusable, and regenerable catalysts for H2 release studies from sodium borohydride methanolysis

Carbon black (CB) obtained from used car tire rubbers were treated with concentrated sulfuric and nitric acids. The oxidized CB (CB‐COO‐Na⁺) is subsequently modified with epichlorohydrin (ECH) and amines including polyethylene imine (PEI). These modified CBs such as CB‐PEI are used as metal‐free catalysts in methanolysis of sodium borohydride (NaBH₄) to produce hydrogen. The hydrogen generation rate (HGR) of 3089 ± 44.69 mL.min^‐1.g^‐1 is accomplished at room temperature with CB‐PEI‐hydrochloric acid (HCl) catalyst. The resulting activation energy of 34.7 kJ/mol for the temperature range of ?20°C to +30°C compares favorably to most of alternative catalysts reported in literature while reaction catalyzing capabilities of CB‐PEI‐HCl particles extend to the subzero temperature range (?20°C‐0°C). The reuse and regeneration studies conducted for the CB‐PEI‐HCl catalyst showed that these catalysts do provide complete conversion at every use up to five consecutive runs and retain 50 ± 2.5% of the original hydrogen generation rate at the fifth consecutive reuse. The CBs‐based catalysts are fully regenerated with HCl treatment.     

Monovalent cation transporters at the plasma membrane in yeasts

Maintenance of proper intracellular concentrations of monovalent cations, mainly sodium and potassium, is a requirement for survival of any cell. In the budding yeast Saccharomyces cerevisiae, monovalent cation homeostasis is determined by the active extrusion of protons through the Pma1 H⁺-ATPase (reviewed in another chapter of this issue), the influx and efflux of these cations through the plasma membrane transporters (reviewed in this chapter), and the sequestration of toxic cations into the vacuoles. Here, we will describe the structure, function, and regulation of the plasma membrane transporters Trk1, Trk2, Tok1, Nha1, and Ena1, which play a key role in maintaining physiological intracellular concentrations of Na⁺, K⁺, and H⁺, both under normal growth conditions and in response to stress.     

Combined innovation and export strategies of KIBS in different regional settings

This paper examines how KIBS establishments combine innovation and exports, and which factors are associated with these combinations. In particular, we hypothesize that KIBS establishments which both export and innovate will be over-represented in metropolitan regions, and under-represented in peripheral regions. Our analysis draws upon a sample of 429 innovative KIBS establishments in the province of Quebec (Canada). We show that strategies differ across space (but not as expected – metropolitan and peripheral strategies are similar), that T-KIBS’ strategies are associated with non-market information sources, and that P-KIBS' strategies are associated with information purchasing. P-KIBS’ and T-KIBS’ strategies vary with the performance of in-house R&D. Taken together, these results suggest that whereas KIBS’ choice of export and innovation strategies do not reflect their ‘hard’ or ‘soft’ nature, the factors associated with this choice do. The similarity between metropolitan and peripheral regions reflects the fact that Quebec’s resource-based peripheral economy is international and innovative.     

Ordered domain characterization in α-Cu-Al alloys from dissolution kinetics studies

Through microcalorimetric experiments, disperse order (DO) dissolution kinetics in preannealedα-Cu-Al alloys containing 19, 13 and 6.5 at % aluminium were adequately described by the integrated kinetic model function arising from the steady-state part of the diffusion field:f(y)=1 − (1−y) 2/3. Domain sizes after the annealing treatment, and also critical radii, were determined from differential scanning calorimetry data analysis at different heating rates. The existence of critical radii indicates that the disperse-order dissolution process is a first-order transition. Nevertheless, it was inferred that for very dilute alloys, only short-range order is present. After pre-annealing the alloys at different temperatures, volume fractions and domain concentrations were computed by employing the above kinetic model under high heating-rate conditions. On the basis of appropriate time constant and diffusion time calculations, the range of such temperatures compatible with equilibrium attainment was established. Prolonged pre-anneals alter the particle distribution, but do not influence either volume fractions or domain sizes. A semi-quantitative particle radius-particle concentration-temperature diagram was proposed forα-Cu-Al alloys.     

Retroperitoneal cystic mass. Giant exophytic gastric leiomyosarcoma

Infantile myofibromatosis is a rare disease characterized by myofibroblastic proliferation, and typically occurs in early infancy. There is a wide spectrum of clinical presentation, which may involve various kinds of tissues in the body. Skin and subcutaneous lesions were the types of tissue most often seen. Although a multicentric form may behave aggressively, a solitary form of the tumor is benign with the possibility of spontaneous regression. Conservative management is justified after proper pathological diagnosis if the tumor involves an aesthetically important area. A case of solitary infantile myofibromatosis involving the upper lip is presented. Partial excision for biopsy was performed and long-term observation was undertaken. The tumor disappeared 3 years postoperatively.     

Plastic analysis of concrete containment structure

Overpressure capacity of a box type concrete containment structure is evaluated. Plastic analysis of the finite element model is performed using a quadrilateral plate element of homogeneous material. A special approach is used to represent nonlinear properties of reinforced concrete, such as concrete cracking and crushing and steel yielding. Those properties are represented by a set of idealized stress-strain curves of equivalent homogeneous sections.The analysis allows for a better estimate of the overpressure capacity of the containment structure while keeping the computer cost low by avoiding the use of the more expensive reinforced concrete brick element.     

Object-oriented specification of user interfaces

This paper presents an object-oriented approach for the specification of graphical user interfaces. Specification starts with the analysis of the end user's operations. The user interface is then designed on the basis of this analysis. Operation analysis is followed by structure and component specification which presents the dialogue structure of the application and the contents of each dialogue. Visualization produces the final screen layouts, and task specification documents the usage of the user interface for the purpose of creating user's guides. The method presented in this paper makes it easier for a designer to take the end user's needs into account. Still, it does not automatically guarantee good quality user interfaces. The top-down nature of the method allows the designer to concentrate on the most important aspects of the user interface and split the design procedure into manageable pieces. Also, the visibility of the process allows the designer to communicate with other people while specifying the user interface. This paper connects the method with the object-oriented specification of entire applications. It briefly explains the connections with object-oriented analysis and design, and demonstrates how to implement the specified user interface in an object oriented fashion. The approach presented in this paper is being applied in the development of a large network management system with about two million lines of C++ code running in the XII environment. Still, the method does not require the specification being implemented with any specific windowing system. The only requirement is that the user interface is based on graphical elements, such as dialogues, push-buttons and text fields.     

Tissue-factor antigen and activity in human coronary atherosclerotic plaques

BACKGROUND: Coronary atherosclerotic-plaque thrombosis is a key event in the pathogenesis of unstable angina and myocardial infarction. Although plaque rupture or fissuring frequently occurs in atherosclerosis, only a small proportion of ruptured plaques develop thromboses. METHODS: Tissue-factor antigen and activity were measured in atherectomy samples from 50 consecutive patients with coronary artery disease (stable angina n = 19, unstable angina n = 24, and myocardial infarction n = 7). FINDINGS: Median tissue-factor antigen and activity concentrations were significantly higher in plaques from patients with unstable angina and myocardial infarction than in those from patients with stable angina (antigen: 66.1 pg/mg [interquartile range 43.8-82.5] vs 32.4 pg/mg [9.8-43.4], p = 0.0001; activity: 0.22 mU/mg [0.17-0.41] vs 0.13 mU/mg [0.05-0.16], p = 0.0004). INTERPRETATION: Tissue-factor, an initiator of the coagulation cascade, may account for the different thrombotic responses to the rupture of human coronary atherosclerotic plaques.