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Content available remote Historia rozwoju techniki deskowań w Polsce
Content available Niektóre aspekty rozwoju elektroniki w Krakowie
Elektronika w Krakowie rozwijała się od momentu odzyskania niepodległości. Początkowo były to badania naukowe prowadzone w Katedrze Fizyki Akademii Górniczej. W drugiej połowie lat trzydziestych XX w. pojawiły się próby uruchomienia produkcji pomiarowych przetworników wielkości nieelektrycznych na elektryczne. Rozwój produkcji na dużą skalę nastąpił po II wojnie światowej. Początkowo były to przetworniki pomiarowe oraz elektroniczne podzespoły bierne. W latach siedemdziesiątych i osiemdziesiątych XX w. asortyment ten rozszerzono o elektroniczne mikroukłady grubowarstwowe czynne i bierne, systemy akwizycji danych oraz kasety do systemów pomiarowych kolejno: Standard 70, CAMAC i EUROCARTA. Przemiany ustrojowe lat dziewięćdziesiątych XX w. spowodowały załamanie rynku elektronicznego w Polsce i wywołały głęboką restrukturyzację produkcji. Jednocześnie pojawiły się nowe inicjatywy w zakresie projektowania i produkcji nowych systemów oświetleniowych oraz automatyki i robotyki przemysłowej, a także montażu elektronicznego.
Electronics in Krakow has been developing since Poland regained independence in 1918. Originally it was scientific research done at the Faculty of Physics of the Academy of Mining and Metallurgy (AGH). In mid-1930s there were attempts to start production of transducers for measurement of non-electrical quantities, however mass production of electronic components happened only after WW2, starting with transducers and continuing with passive elements. In 1970s and 80s it was expanded to include passive and active thick-film microdevices, data acquisition systems and cassettes for acquisition systems 70, CAMAC and EUROCARD. Economic transition of the 1990s caused a breakdown in electronic market in Poland and forced a deep restructuring of manufacturing. At the same time new initiatives appeared in the area of design and manufacturing of lighting systems, industrial automation and robotics and electronic assembly.
In view of social participation in spatial planning, enthusiastic postulates and doubts about its sense and effectiveness appeared. Even among the experts on the subject, hardly anyone is aware how new and with a relatively short history is the phenomenon of public participation in spatial planning. The awareness of this must refrain from excessive optimism as well as pessimism towards this occurrence. Public participation in spatial planning should be given a time to mature. The time is needed for the further development of its methods. More sophisticated than previously, understanding the capabilities and limitations of its use in the planning processes also takes time.
Content available remote Nowoczesne materiały wybuchowe : trzecia generacja
Explosives are chemical compounds or mixtures which, under the influence of an external energetic stimulus of sufficient intensity, develop a rapid exothermic reaction generating large quantity of gas at very high pressure and temperature. Explosives are a chemical energy source of high power (quantity of energy released in a time unit) and high density (quantity of energy per unit of volume). From the application point of view, explosives are divided into blasting, propelling and initiating ones. Of these, blasting explosives are the most common and their production worldwide reaches many millions of tons a year. Detonation is the basic form of their explosive transformation. It can be started by a relatively intense energetic stimulus, for example by a disruptive or other detonator. The linear velocity of propagation of explosive's chemical decomposition during detonation (detonation velocity) reaches several thousand meters per second. During detonation of a blasting explosive, the pressure of detonation products reaches the level of several GPa for mining explosives and as much as 50 GPa for the most powerful military explosives. The detonation pressure value is the measure of an explosive's brisance. It is the brisance that is used to destroy (crush) the structure of a medium. Due to the fast development of mining industry, the demand for effective, safe and inexpensive mining explosives was growing. In the mid-fifties of the 20th century new types of blasting explo-sives appeared on the US market without typical explosive material as part of the composition. The materials were a mixture of ammonium nitrate as oxidant (base ingredient) and an organic or inorganic combustible ingredient. Within a short time, ammonium nitrate fuel oil (ANFO), a mixture of granulated ammonium nitrate and fuel oil characterized by a good flow handy in use, became the most widely used material. Nowadays, ANFO makes more than half of all explosives used in the mining industry worldwide. Simultaneously, another revolutionary innovation was introduced - substantial quantity of water, previously regarded as an ingredient that ruined the explosive properties of mixtures, was purposefully added to the explosive composition. The resulting slurry and emulsion explosives containing a saturated water solution of ammonium nitrate had a semi-liquid consistency, which made it possible to mechanise their manufacture and to load boreholes with explosives on the mining site. The author has specified new, safe varieties of explosives which do not contain typical explosive compounds, with ammonium nitrate as a predominant ingredient. They are named "third generation explosives", the first generation being black gunpowder used for a millennium as the versatile explosive and the second generation being explosive chemical compounds (mostly nitrocompounds, aromatic nitroamines and the esters of nitric acid(V) and aliphatic polyalcohols). In Poland, a research on new varieties of third generation explosives was started in the early 1970s at IPO (ammonium nitrate type) and at WAT (slurry and emulsion type). Based on the research, several modern versions of explosives were developed and brought into production to be used subsequently in the country's open and underground pits. The paper presents the basic historical developments in the field of mining explosives, from black gunpowder to modern safe materials devoid of explosive constituents. Based on the author's own research, the physical and chemical properties of third generation explosives have been characterized in depth, such as ANFO, slurries and emulsions. Particular attention has been paid to the physical structure of mixtures, which plays a key role in determining their explosive characteristics. Keywords: mining high explosives, history of development, explosive properties.
The subject of this article is to analyse the legal situation of forest associations in the Polish legal system, based on historical and contemporary legal regulations. The study presents the relationship of forest associations with non-state forestry and their role in improving the spatial structure of non-state forest land in Poland. The progressive, social and legal as well as economic and legal changes, generating increasing role of the forest associations in the development of new organizational forms in forestry were also indicated. The article widely presents de lege ferenda comments to improve the situation of forest associations in the Polish legal system. In the context of forest associations, the need for political and material changes in the Polish legal system were also indicated.
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