57 research outputs found
Investigating of the Knocking Out Properties of Moulding Sands with New Inorganic Binders Used for Castings of Non-ferrous Metal Alloys in Comparison with the Previously Used
The article presents the results of investigations, which make a fragment of the broad-scale studies carried out as a part of the projectPOIG.01.01.02-00-015/09 “Advanced materials and technologies”.One of the objectives of the introduction of new inorganic binders is to provide a good knocking out properties of moulding sands, whilemaintaining an appropriate level of strength properties.Therefore, a logical continuation of the previous studies were carried out the tests knocking out properties of moulding sands with newinorganic binders, including making moulds, pouring them by the chosen of non-ferrous metal alloys, knoking-out, and determining theknocking out work.The results of the study were related to the research results obtained by applying the moulding sand performed by existing technology
Evaluation of Reclamability of Molding Sands with New Inorganic Binders
One of the purposes of the application of chemically modified inorganic binders is to improve knocking out properties and the related reclamability with previously used in foundry inorganic binder (water glass), which allowing the use of ecological binders for casting non- ferrous metals. Good knocking out properties of the sands is directly related to the waste sands reclamability, which is a necessary condition of effective waste management. Reclamation of moulding and core sands is a fundamental and effective way to manage waste on site at the foundry, in accordance with the Environmental Guidelines. Therefore, studies of reclamation of waste moulding and core sands with new types of inorganic binders (developed within the framework of the project) were carried out. These studies allowed to determine the degree of recovery of useful, material, what the reclaimed sand is, and the degree of its use in the production process. The article presents these results of investigation. They are a part of broader research programme executed under the project POIG.01.01.02-00- 015/09 "Advanced materials and technologies"
Moulding Sands with New InorganicBinders - Ecology Assessment in the Aspect of Work Environment
The development of economy and industry introducing new technologies and materials often means the increased threat of occurrenceof factors harmful to humans and environment. Workers employed in foundries as mould pourers are the group of high professional risk.Foundry moulding sands when poured with liquid metal are a source of the emission of harmful, toxic and carcinogenic (benzene,PAHs) compounds.The paper presents the results of studies on the concentration of chemical compounds emitted in the process of casting aluminiumalloy and brass using moulding sands with the new inorganic binders. The specific values of the exposure indices were compared with thelimit values. This enabled an assessment of the impact of moulding sands on work environment. The obtained results were compared withthe values of contaminants emitted when pouring foundry moulds made from furan sands and bentonite sands with an addition of coaldust.Studies were carried out under the project POIG.01.01.02-00-015/09 "Advanced materials and technologies.
Studies of copper trafficking in a mouse model of Alzheimer's disease by positron emission tomography: comparison of Cu-64 acetate and (64)CuGTSM
Alzheimer's disease can involve brain copper dyshomeostasis. We aimed to determine the effect of AD-like pathology on 64Cu trafficking in mice, using positron emission tomography (PET imaging), during 24 hours after intravenous administration of ionic 64Cu (Cu(II) acetate) and 64Cu-GTSM (GTSMH2 = glyoxalbis(thiosemicarbazone)). Copper trafficking was evaluated in 6–8-month-old and 13–15 month-old TASTPM transgenic and wild-type mice, by imaging 0–30 min and 24–25 h after intravenous administration of 64Cu tracer. Regional 64Cu distribution in brains was compared by ex vivo autoradiography to that of amyloid-β plaque. 64Cu-acetate showed uptake in, and excretion through, liver and kidneys. There was minimal uptake in other tissues by 30 minutes, and little further change after 24 h. Radioactivity within brain was focussed in and around the ventricles and was significantly greater in younger mice. 64CuGTSM was taken up in all tissues by 30 min, remaining high in brain but clearing substantially from other tissues by 24 h. Distribution in brain was not localised to specific regions. TASTPM mice showed no major changes in global or regional 64Cu brain uptake compared to wildtype after administration of 64Cu acetate (unlike 64Cu-GTSM) but efflux of 64Cu from brain by 24 h was slightly greater in 6–8 month-old TASTPM mice than in wildtype controls. Changes in copper trafficking associated with Alzheimer's-like pathology after administration of ionic 64Cu are minor compared to those observed after administration of 64Cu-GTSM. PET imaging with 64Cu could help understand changes in brain copper dynamics in AD and underpin new clinical diagnostic imaging methods
The Mitochondrial Ca(2+) Uniporter: Structure, Function, and Pharmacology.
Mitochondrial Ca(2+) uptake is crucial for an array of cellular functions while an imbalance can elicit cell death. In this chapter, we briefly reviewed the various modes of mitochondrial Ca(2+) uptake and our current understanding of mitochondrial Ca(2+) homeostasis in regards to cell physiology and pathophysiology. Further, this chapter focuses on the molecular identities, intracellular regulators as well as the pharmacology of mitochondrial Ca(2+) uniporter complex
The Effect of OPA1 on Mitochondrial Ca2+ Signaling
The dynamin-related GTPase protein OPA1, localized in the intermembrane space and tethered to the inner membrane of mitochondria, participates in the fusion of these organelles. Its mutation is the most prevalent cause of Autosomal Dominant Optic Atrophy. OPA1 controls the diameter of the junctions between the boundary part of the inner membrane and the membrane of cristae and reduces the diffusibility of cytochrome c through these junctions. We postulated that if significant Ca2+ uptake into the matrix occurs from the lumen of the cristae, reduced expression of OPA1 would increase the access of Ca2+ to the transporters in the crista membrane and thus would enhance Ca2+ uptake. In intact H295R adrenocortical and HeLa cells cytosolic Ca2+ signals evoked with K+ and histamine, respectively, were transferred into the mitochondria. The rate and amplitude of mitochondrial [Ca2+] rise (followed with confocal laser scanning microscopy and FRET measurements with fluorescent wide-field microscopy) were increased after knockdown of OPA1, as compared with cells transfected with control RNA or mitofusin1 siRNA. Ca2+ uptake was enhanced despite reduced mitochondrial membrane potential. In permeabilized cells the rate of Ca2+ uptake by depolarized mitochondria was also increased in OPA1-silenced cells. The participation of Na+/Ca2+ and Ca2+/H+ antiporters in this transport process is indicated by pharmacological data. Altogether, our observations reveal the significance of OPA1 in the control of mitochondrial Ca2+ metabolism
Investigations of a correlation between the type and amount of modifier, high-temperature transformations and residual strength of sands with modified sodium silicates
W artykule przedstawiono wyniki badań wysokotemperaturowych modyfikowanych próbek uwodnionego krzemianu sodu i mas z jego udziałem. Określony został wpływ dodatków morfoaktywnych jako modyfikatorów uwodnionego krzemianu sodu, na właściwości (kohezyjno-adhezyjne) technologiczne mas formierskich wykonanych z udziałem tego spoiwa, określone w podwyższonych temperaturach, w aspekcie poprawy wybijalności tych mas z odlewu. W wyniku badań wytypowany został najkorzystniejszy pod tym względem dodatek morfoaktywny.The article presents the results of high-temperature investigations of the modified samples of hydrated sodium silicate and of the sand mixtures with an addition of this compound. To improve the knocking out properties of these sands when poured with molten metal, the effect of morphoactive additives used as modifiers of the hydrated sodium silicate on the high-temperature technological (cohesive-adhesive) properties of moulding sands prepared with an addition of this binder was determined. As a result of the investigations, an optimum addition of the morphoactive agent was selected
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