The influence of the shape of wax pattern on the kinetics of drying of ceramic moulds

Multi-layer ceramic moulds are built of slurry and a refractory material forming their matrices. From the moment when the European Union introduced regulations concerning the environment protection requiring substitution of alcoholic binders by aqueous binders, several difficulties in making moulds occurred. The influence of selected factors on drying ceramic moulds applied in the investment casting technology was determined by the gravimetric method. It was found that each successive layer, of a similar thickness, is drying longer than the previous one. The drying time of layers forming a deep cavities is several times longer as compared with drying open surfaces (external). Extension scale of the drying time is a function of the slenderness of cavities

Adult "care", children's "needs", social ways of managing child sexuality

W przeważającej większości społeczeństw seks to praktyka przypisywana osobom dorosłym, jednak za stały obiekt społecznego niepokoju uznaje się płciowość dzieci. Analizy odnoszące się do dziecięcej seksualności wymagają czegoś więcej niż stwierdzenia obecności zróżnicowanych sposobów rozumienia tego, co służy najlepiej pojętemu interesowi dzieci. Przyjęłam za M. Stainton Rogers, że niezbędne jest tu eksplorowanie dyskursu, które pozwoli dociec, skąd się wzięły wartości fundujące konstrukcje dziecięcej płciowości. Punktem odniesienia dla tych eksploracji stał się kształtujący zachodnią politykę i praktykę społeczną dyskurs potrzeb. W jego ramach pojawiają się dążenia do identyfikacji podstawowych "potrzeb" dzieci i odnalezienia rozwiązań "problemów" wiążących się z realizacją tych "potrzeb". W niniejszym tekście dyskurs potrzeb służy jako punkt wyjścia dla interpretacji historycznych oraz współczesnych sposobów "tworzenia" dziecięcej płciowości. W swoich rozważaniach zidentyfikowałam elementy dyskursu "potrzeb" i "problemów" dzieci wiążących się z płciowością. Nie pominęłam dyskursu nowych zagrożeń generowanych szczególnie w przestrzeni publicznej, w której funkcjonują dzieci. Następnie przyjrzałam się działaniom łączącym się z rozwiązaniem "problemów" dziecięcej seksualności (w tym praktykom ich normalizacji). Rozważaniom tym towarzyszyła analiza konstrukcji dzieci i ich seksualności, które znajdują się w centrum konkretnych "zagrożeń". Odnosząc się do "potrzeb" i "problemów" dziecięcej płciowości, znaczenie nadałam również generowanym w odniesieniu do nich napięciom.In the majority of societies, sex is a practice attributed to adults, however, the sexuality of children is considered a permanent object of social anxiety. Analyzes related to child sexuality require more than the presence of diverse ways of understanding what serves the best interests of children. Following M. Stainton Rogers, I assumed that it is necessary to explore the discourse which will allow to find out where the values found in the construction of child sexuality came from. The point of reference for these explorations has become the discourse shaping the western policy and social practice. Within it, there are strivings to identify the basic "needs" of children and find solutions to the "problems" associated with the implementation of these "needs". In this text, the discourse of needs serves as a starting point for historical interpretations and contemporary ways of "creating" childlike sexuality. In my deliberations, I identified the elements of the discourse of "needs" and "problems" of children associated with sexuality. I have not omitted the discourse of new threats generated especially in the public space in which children function. Next, I looked at the activities connected with solving the "problems" of child sexuality (including the practices of their normalization). These considerations were accompanied by an analysis of the structure of children and their sexuality, which are at the center of specific "threats". Referring to the "needs" and "problems" of childhood sexuality, I also paid attention to the tensions generated in relation to them

O podręcznikowej (homo)seksualności w kontekście polskim – od paniki moralnej do wojny kulturowej

In this article, the new regulation of intimacy and a cultural war became the context of analysis for homosexuality, which is present in textbooks for upbringing to life in the family. Over the last dozen or so years, homosexuality issues have occurred in this group of textbooks in a diverse context and form. Homosexuality was called, among others, sexual atypicalness, a disorder located alongside fragments about persuading minors to sexual contact, a “direction” setting a road from which young people can turn back or – only in the last versions of the textbook – sexual orientation. The context for introducing changes became in the text of the clash between the entities guarding the “old” order and supporters of its change, opposing the normative and obligatory character of heterosexual behaviour.W niniejszym opracowaniu nowy sposób regulowania intymności oraz wojna kulturowa stały się kontekstem analiz dla obecnej w podręcznikach do zajęć z zakresu wychowania do życia w rodzinie homoseksualności. Na przestrzeni ostatnich kilkunastu lat kwestie dotyczące homoseksualizmu występowały w tej grupie podręczników w zróżnicowanym kontekście i postaci. Homoseksualizm nazywano m.in. nietypowością seksualną, zaburzeniem, „kierunkiem” wyznaczającym drogę, z której młodzi ludzie mogą zawrócić czy – dopiero w ostatnich wersjach podręcznika – orientacją seksualną. Kontekstem dla wprowadzania zmian stały się opisane w pracy starcia pomiędzy podmiotami strzegącymi „starego” porządku a zwolennikami jego zmiany, sprzeciwiającymi się normatywnemu i obowiązkowemu charakterowi zachowań heteroseksualnych

Density Distribution and Resin Migration Investigations in Samples of Sand Core Made by Blowing Method

Resin migration in a core can occur during the core production process performed by blowing methods in which the core sand is transported into the core box as a two-phase sand-air flux characterized by various working parameters (working pressure, shooting time, volumetric concentration). This migration is the result of the resin being blown off from the matrix grain surfaces by compressed air. The methodology of the investigation of this effect developed at AGH University of Science and Technology is presented in this paper. The results of the resin migration tests obtained for cores made with cold-box technology at various working parameters of the shooting process are also shown

The drying kinetics of protective coatings used on sand molds

Investigation results of the drying rate of the selected protective coatings (water and alcohol) are presented in the article. Coating drying rate was determined for the first and second layers. The coating was applied to moulding sand cores. The rate of drying coatings were tested for three coating apparent viscosities estimated by means of the Ford 4 mm cup. Drying rates of the protective coating were examined by using the gravimetric technique and ultrasonic technique. Measurements were carried out in a continuous way under controlled conditions: constant ambient temperature and air humidity. Research shows that the drying time of the second coating layer is longer by 20 – 30 % than the first layer

Influence of refining treatments on the properties of Al-Si alloys

The article focused on researching the influence of Ti, B, Sr and Na as a modifying treatment elements for Al-Si alloys. The influence of alloying additives such as Cu and Cr was studied. Tensile strength Rm, elongation A5 and HB hardness was analysed, as well as the influence of the above-mentioned elements on the microstructure and solidification of alloys containing a varied content of Si, within the 7 ÷ 16 % range. The influence of heat treatment on the alloy properties was also researched

Copper alloys in investment casting technology

This paper presents research results in the field of casting technology of copper and copper alloys using the investment casting technology, both from historical as well as modern technology perspective. The analysis of exemplary elements of the old casting moulds is included, as well as the Bronze Age casts. The chemical content of various copper alloys was determined and the application of lost wax method was confirmed in the Bronze Age workshop. At present, investment casting method is used for manufacturing high-quality casts, especially products for power engineering that is why it demands respecting very rigorous technological requirements. The casts were characterised based on microstructure research, chemical composition and conductivity in relation to oxygen content