Fume Formation from Oxidation of Liquid SiMn Alloy

Thermally generated fumes from the production of manganese ferroalloys are mostly composed of metallic oxides generated due to reaction between high-temperature molten metal and ambient oxygen in the air. In the current study, the fume characteristics (particle morphology, compositions and particle size distribution) from the exposure of a SiMn alloy under an impinging air jet, in the temperature range 1400–1700 °C, were experimentally investigated. Combinations of manganese- and manganese/silicon oxide particles were found in the system, displaying both crystalline and amorphous structures. The governing generation mechanisms of fume from both a thermodynamic and a kinetic perspective are discussed.     

Improving Conviviality in Public Places： The Case of Naples, Italy

Under the umbrella concept of conviviality in public spaces, a research project on the rehabilitation of urban areas for commercial and retail uses---as engine of a complex process of production of places for social and cultural mixit6--has been defined. The aim of this research has been to produce useful tools for coping with the abandonment of public spaces in former commercial urban areas, without generating anonymous and globalized commercial districts. Through involving local stakeholders in a participatory process, the first phase of the research here presented needs to demonstrate the possible effectiveness of a pilot action plan in dealing with both isolation and gentrification processes of historical centres. The main hypothesis is that traditional retailers should be considered an essential element to ensure effective public use of urban public spaces. The research methodology is based on a qualitative approach. Focussing on the process of impoverishment within local commercial districts, the research group started working with local stakeholders in order to identify priorities and criticisms for enhancing a regeneration process. The case study to be carried out in Naples is the historical market place of Piazza Mercato in the Citth Bassa of Naples （Italy）.     

Surface and Interaction Characteristics of Liquid Crystal Polymers and their Miscibility with Thermoplastic Hosts

Inverse gas chromatographic measurements have shown that the surface of thermo-tropic liquid crystal polymers, (TLCP), are capable of mainly dispersion force (L/W) interactions, with only slight contributions from non-dispersion (acid-base) forces. Structural moieties capable of non-dispersive interactions are primarily oriented into the TLCP bulk, perhaps accounting for the self-assembly effects in these polymers. Moreover, nondispersive surface forces were found to be thermolabile, so that above characteristic temperatures only L/W forces remain. Blends of TLCP with polycarbonate and polyetherimide hosts prepared below the characteristic temperatures displayed morphology typical of immiscible blends. When prepared at, and quenched from, temperatures above the pertinent characteristic value, electron micrographs showed evidence of adhesion at matrix/TLCP contacts, simulating the behavior of more miscible systems.     

A high-resolution digital time-interval measurement instrument

A new method for time-interval measurements is described and the results of measurements on a prototype are given. This method uses a virtually periodic exponential signal as the reference clock and consists of measuring both the phase deviation and the number of cycles of this clock signal between the beginning and the end of the unknown time-interval. The use of two auxiliary sinusoidal signals in order to measure the phase of the corresponding periodic exponential signal is discussed, also considering the main causes of error. The functional block diagram of the prototype is described in detail and the measurement results show that a resolution improvement of two orders of magnitude with respect to the period of the clock signal can easily be obtained.     

Enantioselective hydrolysis of some 2-aryloxyalkanoic acid methyl esters and isosteric analogues using a penicillin G acylase-based HPLC monolithic silica column

A technique based on liquid chromatography has been developed to facilitate studies of enantioselectivity in penicillin G acylase (PGA)-catalyzed hydrolysis of some 2-aryloxyalkanoic acid methyl esters and isosteric analogues. PGA was covalently immobilized on an aminopropyl monolithic silica support to create an immobilized HPLC-enzyme reactor. Two sets of experimental data were drawn to calculate the enantioselectivity (E) of the kinetically controlled enantiomer-differentiating reaction, the degree of substrate conversion and the enantiomeric excess of the product. The developed enzymatic reactor was coupled through a switching valve to an achiral analytical column for separation and quantitation of the hydrolysis products. The enantiomeric excess was determined off-line on a PGA-chiral stationary phase. In this way, highly precise E values were determined. A computational study related to the hydrolysis of the considered racemic esters was also carried out in order to unambiguously clarify both the substrate specificity and the enantioselectivity displayed by PGA.     

Programming Delayed Dissolution Into Sacrificial Bioinks For Dynamic Temporal Control of Architecture within 3D-Bioprinted Constructs

Sacrificial printing allows introduction of architectural cues within engineered tissue constructs. This strategy adopts the use of a 3D-printed sacrificial ink that is embedded within a bulk hydrogel which is subsequently dissolved to leave open-channels. However, current conventional sacrificial inks do not recapitulate the dynamic nature of tissue development, such as the temporal presentation of architectural cues matching cellular requirements during different stages of maturation. To address this limitation, a new class of sacrificial inks is developed that exhibits tailorable and programmable delayed dissolution profiles (1–17 days), by exploiting the unique ability of the ruthenium complex and sodium persulfate initiating system to crosslink native tyrosine groups present in non-chemically modified gelatin. These novel sacrificial inks are also shown to be compatible with a range of biofabrication technologies, including extrusion-based printing, digital-light processing, and volumetric bioprinting. Further embedding these sacrificial templates within cell-laden bulk hydrogels displays precise control over the spatial and temporal introduction of architectural features into cell-laden hydrogel constructs. This approach demonstrates the unique capacity of delaying dissolution of sacrificial inks to modulate cell behavior, improving the deposition of mineralized matrix and capillary-like network formation in osteogenic and vasculogenic culture, respectively.