CASTING OF Al-Si ALLOYS IN THE FULL-MOULD TECHNOLOGY. PROCESS CONDITIONS

A review of various technologies using expendable casting patterns made of expanded polystyrene is given in the paper. The results of our own investigations on implementing this technology at the pilot-plant scale – for the art castings series – were presented. The results of tests of materials and moulds applied in the full-mould technology were shown. Gas evolution tendencies of expanded polystyrenes and protective coatings were estimated. Gas evolutions were described as functions of the polystyrene heating temperature. The tests of protective coatings used in this technology were performed and strength (Rm), permeability (P), and gas evolution tendency of these coatings assessed. New solutions developed by the team of researchers were applied in testing coating strength, permeability, and the gas evolution tendency of expanded polystyrene. A good correlation between the results of coating properties and the obtained casting quality was found. Coatings, which were characterised by higher strengths and better permeability, allowedus to produce castings without surface or inner faults

When you hear hooves, you should look for... zebras

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Epic battles in endocrinology — malignant pheochromocytoma: a case report

The rarity of malignant pheochromocytoma coupled with the lack of definitive predictors of malignancy and the variability of clinical course, poses a significant diagnostic and therapeutic challenge. Since data on treatment is so scarce, case reports are a valuable source of knowledge for clinicians. This case report describes the medical history of a woman, aged 51 at the time of initial diagnosis and adrenalectomy. Within over 5 years she presented with recurrent relapse of tumour in adrenal gland bed and multiple distant metastases to descending colon, abdominal wall, postoperative scars, and the peritoneum. Neither before diagnosis nor during the whole follow-up were symptoms associated with pheochromocytoma present. The treatment administered to our patient consisted of numerous debulking surgeries along with administration of both hot and cold somatostatin analogues. We believe that debulking surgeries played a substantial role in enabling the patient to survive nearly 6 years despite aggressive clinical course of pheochromocytoma. She passed away in 2012 as a result of postlaparotomy complications. We stress the role of debulking surgery in the treatment of malignant pheochromocytoma and summarise currentliterature

Machine learning on the road to unlocking microbiota's potential for boosting immune checkpoint therapy

The intestinal microbiota is a complex and diverse ecological community that fulfills multiple functions and substantially impacts human health. Despite its plasticity, unfavorable conditions can cause perturbations leading to so-called dysbiosis, which have been connected to multiple diseases. Unfortunately, understanding the mechanisms underlying the crosstalk between those microorganisms and their host is proving to be difficult. Traditionally used bioinformatic tools have difficulties to fully exploit big data generated for this purpose by modern high throughput screens. Machine Learning (ML) may be a potential means of solving such problems, but it requires diligent application to allow for drawing valid conclusions. This is especially crucial as gaining insight into the mechanistic basis of microbial impact on human health is highly anticipated in numerous fields of study. This includes oncology, where growing amounts of studies implicate the gut ecosystems in both cancerogenesis and antineoplastic treatment outcomes. Based on these reports and first signs of clinical benefits related to microbiota modulation in human trials, hopes are rising for the development of microbiome-derived diagnostics and therapeutics. In this mini-review, we're inspecting analytical approaches used to uncover the role of gut microbiome in immune checkpoint therapy (ICT) with the use of shotgun metagenomic sequencing (SMS) data

The Importance of TDA Thermal Analysis in an Automated Metallurgical Process

The article presents the results of research and work related to the implementation of the research and development project POIR.01.01.01-00-0120/17 co-financed by the EU, through the NCBR, entitled: Innovative technology using thermal analysis, TDA, of self-feeding manufacturing of high-quality cast iron to produce new generation, enhanced performance casts. In many foundries, thermal derivative analysis (TDA) is used in addition to chemical analysis to evaluate the physical and chemical properties of an alloy while it is still in the melting furnace or ladle and before it is poured into the mold. This fact makes it possible to improve the metallurgical quality of the alloy by introducing alloying additives, carburizers or modifiers into the furnace as part of the pre-modification or primary or secondary modification in the ladle or when pouring into molds. Foundry machinery (modifier dosing systems and spheroidizing station) is very important in these operations. Only the full synergy of modern equipment with modern technology ensures high quality and repeatability of the casting process. The article mainly discusses the obtained parameters of TDA analysis (with the use of the ITACA system) at different stages of melting and how to improve them by using modern and fully automated dosing systems (Itaca OptiDose, ItacaWire and ItacaStream). Special attention was paid to the minimum temperature of the eutectoid. The change of its value after the modification process, its influence on the quality of the melted metal, a very strong correlation with the number of nuclei and the number of graphite precipitations in the casts were shown

Evaluation of pulsed laser deposited thin films properties on the basis of the nanoindentation test

The overall goal of the research, is development of the numerical model capable of replicating local heterogenous material behavior of thin film materials under loading conditions. This particular work is focused on determination of flow stress characteristics of investigated TiN thin film based on the nanoindentation test. To properly recalculate measured load-displacement values into the required stress-strain curve an inverse analysis techniques are used. Subsequent stages including deposition process of TiN layer, room temperature nanoindentation tests and development of direct problem numerical model for the inverse analysis are described. Capabilities of the approach are also discussed within the work

Circadian Profile of Salivary Melatonin Secretion in Hypoxic Ischemic Encephalopathy

Purpose. In the present study, the salivary melatonin secretion in the hypoxic ischemic encephalopathy (HIE) children was measured. The logit model was fitted to the data to obtain the salivary dim light melatonin onsets (DLMOs), and the results were compared with the values estimated from the classic threshold method with a linear interpolation and those previously published for the blood measurements. Materials and Methods. 9 patients suffering from HIE aged from 65 to 80 months were included in the study. The melatonin levels were assessed by a radioimmunoassay (RIA). The diurnal melatonin secretion was estimated using a nonlinear least squares method. Student’s t-test and the Mann–Whitney U test were used for the comparisons of the obtained parameters. Results. The circadian profiles of the melatonin secretion for both calculation methods do not differ statistically. The DLMO parameters obtained in the blood and saliva samples in children with hypoxic is chemic encephalopathy were similar

How Surface Properties of Silica Nanoparticles Influence Structural, Microstructural and Biological Properties of Polymer Nanocomposites

The aim of this work was to study effect of the type of silica nanoparticles on the properties of nanocomposites for application in the guided bone regeneration (GBR). Two types of nanometric silica particles with different size, morphology and specific surface area (SSA) i.e., high specific surface silica (hss-SiO2) and low specific surface silica (lss-SiO2), were used as nano-fillers for a resorbable polymer matrix: poly(L-lactide-co-D,L-lactide), called PLDLA. It was shown that higher surface specific area and morphology (including pore size distribution) recorded for hss-SiO2 influences chemical activity of the nanoparticle; in addition, hydroxyl groups appeared on the surface. The nanoparticle with 10 times lower specific surface area (lss-SiO2) characterized lower chemical action. In addition, a lack of hydroxyl groups on the surface obstructed apatite nucleation (reduced zeta potential in comparison to hss-SiO2), where an apatite layer appeared already after 48 h of incubation in the simulated body fluid (SBF), and no significant changes in crystallinity of PLDLA/lss-SiO2 nanocomposite material in comparison to neat PLDLA foil were observed. The presence and type of inorganic particles in the PLDLA matrix influenced various physicochemical properties such as the wettability, and the roughness parameter note for PLDLA/lss-SiO2 increased. The results of biological investigation show that the bioactive nanocomposites with hss-SiO2 may stimulate osteoblast and fibroblast cells’proliferation and secretion of collagen type I. Additionally, both nanocomposites with the nanometric silica inducted differentiation of mesenchymal cells into osteoblasts at a proliferation stage in in vitro conditions. A higher concentration of alkaline phosphatase (ALP) was observed on the material modified with hss-SiO2 silica

Formowanie i spiekanie nanometrycznego proszku tlenku cyrkonu praca doktorska /

Tyt. z ekranu tytułowego.Praca doktorska. Akademia Górniczo-Hutnicza im. Stanisława Staszica (Kraków), 2006.Bibliogr.Dostępna także w wersji drukowanej.Tryb dostępu: Internet.Nanotechnologia, nanomateriały, metaliczne materiały nanokrystaliczne, otrzymywanie, kondensacja w gazie obojętnym, metody mechaniczne, własności metalicznych materiałów nanokrystalicznych, mechaniczne, magnetyczne, zastosowanie, ceramiczne materiały nanokrystaliczne, środowisko gazowe, cieczy, reakcje w stanie stałym, zastosowanie nanometrycznych proszków ceramicznych, formowanie, prasowanie na sucho, formowanie z zawiesin, spiekanie swobodne, pod ciśnieniem, przezroczystość, odkształcenie superplastyczne, opis eksperymentu, wyniki, plan, wybór tworzywa, preparatyka, charakterystyka proszku, powierzchnia właściwa, BET, dyfraktometria rentgenowska, obserwacje mikroskopowe, TEM, udział objętościowy części stałych w zawiesinie, peptyzacja zawiesiny poprzez zmianę pH, poprzez dodatek upłynniaczy, prasowanie filtracyjne zawiesin, prasa filtracyjna, przebieg procesu, zawiesina sflokulowana, speptyzowana, wybór ciśnienia prasowania, suszenie, spiekanie, charakterystyka wyjściowych próbek, próbki formowane z zawiesiny sflokulowanej, speptyzowanej, w warunkach nieizotermicznych, izotermicznych, skurcz liniowy, gęstość pozorna próbek, rozmiar krystalitów, XRD, rozkład wielkości porów w próbkach, obserwacje mikroskopowe powierzchni przełamów, SEM, spiekanie próbek formowanych z zawiesiny speptyzowanej, prasowanych jednoosiowo, badania porównawcze, wybrane właściwości otrzymanego tworzywa, wytrzymałość mechaniczna, odkształcenie plastyczne w podwyższonej temperaturze, charakterystyka proszku r.s. ZrO2, prasowanie filtracyjne, charakterystyka surowych próbek, prasowanie jednoosiowe, prasowanie filtracyjne nanoproszk