The identification of pyrolysis products of the alphaset binder with gas chromatography/mass spectrometry

Pyrolysis-gas chromatography-mass spectrometry (PyGC/MS) was used to identify the major organic products created by pyrolysis of the ALPHASET binder components: hardener/catalyst, resin and cured resin. During the casting process, the cores and moulds are subjected to intense heat from the molten metal. As a result the organic components undergo thermal decomposition and produce a number of complex organic compounds. In this study, the organics were tentatively identified by GC/MS after pyrolysis of the components at 700, 900 and 1100°C

Thermal decomposition of foundry resins: A determination of organic products by thermogravimetry–gas chromatography–mass spectrometry (TG–GC–MS)

AbstractThe article presents the results of research on thermal decomposition of Ester-Cured Alkaline Phenolic No-Bake (ALPHASET) binders used in molding technology. In the ALPHASET system phenol-formaldehyde resin of resole type is cured with a liquid mixture of esters. Under the influence of the molten metal the thermal decomposition of the binder follows, resulting in the evolution of gases, often harmful, e.g. from benzene, toluene, ethylbenzene and xylenes (BTEX) or Polycyclic Aromatic Hydrocarbon (PAH) groups. The identification of gases evolved during the pyrolysis of the binders was carried out and their decomposition temperatures were determined using the Thermogravimetry–Gas Chromatography–Mass Spectrometry (TG–GC–MS) technique. The tests were subjected to two types of binders from different manufacturers. Among the products of pyrolysis there have been identified mainly benzene and its derivatives, and phenol and its derivatives. Compounds identified in pyrolytic gas are largely considered to be harmful to humans and the environment (some of the compounds are carcinogenic and mutagenic). The presented results of the TG–GC–MS measurements show that the applied analytic methods are feasible to perform a qualitative and also quantitative characterization of the binder samples

"Self-regulation," a new facet of Hox genes' function

PMCID: PMC4482672[Background]: Precise temporal and spatial expression of the clustered Hox genes is essential for patterning the developing embryo. Temporal activation of Hox genes was shown to be cluster-autonomous. However, gene clustering appears dispensable for spatial colinear expression. Generally, a set of Hox genes expressed in a group of cells instructs these cells about their fate such that the differential expression of Hox genes results in morphological diversity. The spatial colinearity is considered to rely both on local and long-range cis regulation. [Results]: Here, we report on the global deregulation of HoxA and HoxD expression patterns upon inactivation of a subset of HOXA and HOXD proteins. [Conclusions]: Our data suggest the existence of a >self-regulation> mechanism, a process by which HOX proteins establish and/or maintain the spatial domains of the Hox gene family and we propose that the functionally dominant HOX proteins could contribute to generating the spatial parameters of Hox expression in a given tissue, i.e., HOX controlling the establishment of the ultimate HOX code.Grant sponsor: the Spanish Government; Grant number: BFU2011-24972; Grant sponsor: the Canadian Institutes for Health Research; Grant number: MOP-82880; Grant number: 126110. This work was supported by the Spanish Government to M.R. and by the Canadian Institutes for Health Research as well as the Canada Research Chair program to M.K. R.S was supported by a Formación Profesorado Universitario fellowship from the Spanish Ministry of Science and Innovation and currently supported by the Angelo Pizzagalli postdoctoral fellowship.Peer Reviewe

Zinc ferrite nanoparticles as perspective functional materials for applications in casting technologies

In this article it discuss on possible application of magnetic oxide nanoparticles, namely non-stoichiometric zinc ferrite nanoparticles as a functionalizing agent in foundry processes. Thermal analysis showed a weight loss of the sample at 1 273 K in an amount of 7,7 %, which is a result of the following processes taking place in different temperature ranges. Upon its thermal treatment Zn0,4Fe2,6O4 decomposes to zinc oxide and iron (III) oxide (first stage) and next to iron (II,III) oxide and oxygen (second stage). The degree of decomposition was expressed as Fe2+ / Fetotal. Mössbauer spectroscopy showed that the over 30 % of Fe3+ present in starting material was reduced to Fe2+

FTIR spectroscopy of water glass - the binder moulding modified by ZnO nanoparticles

The subject of the paper is the determination of the infl uence of the colloidal nanoparticles of zinc oxide on the structure of sodium water glass. Nanoparticles of zinc oxide in ethanol solvent were introduced into the water glass. The modification and structural changes were determined by means of the FT-IR absorption spectra. In order to determine the kind of infl uence: binder-modifier the spectroscopic FTIR analysis of samples of a fresh binder and of a binder hardened for 24 h in the air was performed by means of the spectrometer Digilab Excalibur with a standard DTGS detector

Thermal decomposition of foundry resins: A determination of organic products by thermogravimetry–gas chromatography–mass spectrometry (TG–GC–MS)

AbstractThe article presents the results of research on thermal decomposition of Ester-Cured Alkaline Phenolic No-Bake (ALPHASET) binders used in molding technology. In the ALPHASET system phenol-formaldehyde resin of resole type is cured with a liquid mixture of esters. Under the influence of the molten metal the thermal decomposition of the binder follows, resulting in the evolution of gases, often harmful, e.g. from benzene, toluene, ethylbenzene and xylenes (BTEX) or Polycyclic Aromatic Hydrocarbon (PAH) groups. The identification of gases evolved during the pyrolysis of the binders was carried out and their decomposition temperatures were determined using the Thermogravimetry–Gas Chromatography–Mass Spectrometry (TG–GC–MS) technique. The tests were subjected to two types of binders from different manufacturers. Among the products of pyrolysis there have been identified mainly benzene and its derivatives, and phenol and its derivatives. Compounds identified in pyrolytic gas are largely considered to be harmful to humans and the environment (some of the compounds are carcinogenic and mutagenic). The presented results of the TG–GC–MS measurements show that the applied analytic methods are feasible to perform a qualitative and also quantitative characterization of the binder samples

Emission of polycyclic aromatic hydrocarbons (PAHs) and benzene, toluene, ethylbenzene and xylene (BTEX) from the furan moulding sands with addition of the reclaim

In this paper, the results of decomposition of a moulding sand with furfuryl resin also on a quartz matrix and with additions of a reclaimed material, under industrial conditions, are presented. Investigations of the gases emission in the test foundry plant were performed according to the original method developed in the Faculty of Foundry Engineering, AGH UST. The dependence of the emitted PAHs and BTEX group substances and ignition losses on the reclaim fraction in a moulding sand are of a linear character of a very high correlation coefficient R2. On the bases of the derived equations, it is possible to determine the amount of the emitted hazardous substances from the moulding sand containing the known fraction of the reclaim

Role of Austenitization Temperature on Structure Homogeneity and Transformation Kinetics in Austempered Ductile Iron

This paper considers the important factors of the production of high-strength ADI (Austempered Ductile Iron); namely, the austenitization stage during heat treatment. The two series of ADI with different initial microstructures were taken into consideration in this work. Experiments were carried out for castings with a 25-mm-walled thickness. Variable techniques (OM, SEM, dilatometry, DSC, Variable Magnetic Field, hardness, and impact strength measurements) were used for investigations of the influence of austenitization time on austempering transformation kinetics and structure in austempered ductile iron. The outcome of this work indicates that the austenitizing temperature has a very significant impact on structure homogeneity and the resultant mechanical properties. It has been shown that the homogeneity of the metallic matrix of the ADI microstructure strongly depends on the austenitizing temperature and the initial microstructure of the spheroidal cast irons (mainly through the number of graphite nodules). In addition, this work shows the role of the austenitization temperature on the formation of Mg–Cu precipitations in ADI

Cohesion and adhesion properties of modified water glass with colloidal solutions of ZnO

The article discusses the issue of the influence of colloidal solutions of nanoparticles of ZnO obtained using original method on physical and chemical properties (cohesions, adhesion, wettability) of water glass. Adhesion and cohesion strength has been determined on the basis of own methodology of measurement using a special apparatus. The results of the above measurements have been supplemented with selected measurements of quartz wettability by the modified binder. Also, exemplary results have been presented of tests involving basic properties of moulding sans containing an addition of the aforementioned binder. In conclusions, the influence of binder modification on the properties of moulding sands have been presented

FTIR spectroscopy of water glass - the binder moulding modified by ZnO nanoparticles

The subject of the paper is the determination of the infl uence of the colloidal nanoparticles of zinc oxide on the structure of sodium water glass. Nanoparticles of zinc oxide in ethanol solvent were introduced into the water glass. The modification and structural changes were determined by means of the FT-IR absorption spectra. In order to determine the kind of infl uence: binder-modifier the spectroscopic FTIR analysis of samples of a fresh binder and of a binder hardened for 24 h in the air was performed by means of the spectrometer Digilab Excalibur with a standard DTGS detector