10 research outputs found

    Mobilność gruntów w drodze dzierżawy w gospodarstwach rodzinnych i wielkoobszarowych w latach 2000-2014

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    The aim of the study is to present the mobility of agricultural land by way of lease and the distribution of the land for the family farms enlargement and for creation of new large-scale farms. It provides a detailed analyses of the dynamics of land leasing in the period of 2000-2014 and the extent of land remaining in the lease. It pointed out the changes that were taking place in the leased areas and in numbers of concluded lease agreements. In the study were used descriptive method, descriptive-comparative method as well as statistical and tabular method

    SELECTED QUALITY SIGNS OF FOOD PRODUCTS IN POLAND, LEGAL AND ECONOMIC ASPECTS

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    The aim of the study was to identify whether and to what extent the selected quality signs guarantee food safety understood in a broader sense as a food quality and whether the legal requirements governing their functioning aff ect their use by food producers. Detailed analysis concern the selected signs encountered in the Polish food market: “Poznaj Dobrą Żywność” (Try Fine Food), “Jakość Tradycja” (Quality Tradition), “Lista Produktów Tradycyjnych” (Traditional Products List) and Protected Designation of Origin (PDO), Protected Geographical Indication (PGI) and Traditional Speciality Guaranteed (TSG). Considerable attention was paid to their legal requirements related to ensuring food safety, because, as a factor in the economic environment, they strongly infl uence the activity of entities in agribusiness. For the study dogmatic method and documentary method for the secondary data collection were used. Results were elaborated and shown by the descriptive method and graphic techniques. The least of all the quality signs in Poland are those legally protected by the EU (9 PDO, 19 PGI, 9 TSG), which is undoubtedly linked with high EU requirements of their use for producers. Among all of the analysed signs, the most popular is the Polish “Traditional Products List” (1347 registered products till the end of 2014), probably due to the lack of any institutional verifi cation ex ante and ex post of statutory requirements fulfi lment regarding the quality of the products to be put on the List. Considerations can be the basis for further research, especially in terms of proposing the creation of legal and economic instruments or improvements to existing ones in terms of helping producers to meet the high legal requirements of the discussed quality signs

    CONSUMER AWARENESS OF REGIONAL PRODUCTS – SELECTED RESEARCH RESULTS

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    The study was based on field research. The main goal of the work was to determine the level of consumer awareness of regional products and to examine the statistical relationship between the age and education level of respondents and their declaration of purchasing this type of product. Data collection was performed in Sudeten districts, because the described study was part of a research project concerning the introduction of a new regional product „Sudeten Beef” into this area. The study was conducted in 2012 using direct interviews with 219 respondents. On the basis of the investigation it could be said that the surveyed respondents had little awareness of regional products. The statistical analysis confirmed a weak correlation between age and level of education and declarations of purchasing regional products. This study is of a preliminary character and the results are not representative of the whole Polish population, but they should be regarded as a good starting point for further in-depth research

    Photopolymerization in additive manufacturing of ceramics

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    O ile technologie druku 3D dla tworzyw sztucznych i metali są powszechnie stosowane, o tyle w przemyśle ceramicznym metody te są ciągle udoskonalane, tak aby móc je stosować komercyjnie. Ze względu na szereg proponowanych rozwiązań przyrostowe techniki formowania uznawane są za potencjalnie najlepsze w otrzymywaniu elementów ceramicznych o skomplikowanych kształtach. W porównaniu z konwencjonalnymi procesami obróbki skrawanej metody te są konkurencyjne w szczególności w przypadku formowania wyrobów jednostkowo lub małoseryjnie charakteryzujących się unikalnymi kształtami i rozmiarami. W niektórych metodach druku 3D wykorzystywana jest reakcja fotopolimeryzacji rodnikowej jako mechanizm utwardzania pojedynczej wydrukowanej warstwy. W tego typu technikach istotnym etapem jest opracowanie składu i przygotowanie stabilnej w czasie, homogenicznej, fotoutwardzalnej dyspersji ceramicznej. Masy te są zazwyczaj układami organicznymi i do ich przygotowania konieczne jest stosowanie często szkodliwych dla środowiska związków organicznych. W pracy sprawdzono możliwość zastosowania wodnych, fotoutwardzalnych dyspersji ceramicznych w formowaniu elementów ceramicznych o skomplikowanym kształcie wykonanych z tlenku glinu za pomocą metody cyfrowego przetwarzania światła (DLP). Wyniki badań wykazały, że opracowane masy ceramiczne charakteryzują się odpowiednimi właściwościami reologicznymi (lepkość przy szybkości ścinania 10 s-1 nie przekracza 0,5 Pa·s) i dużymi głębokościami sieciowania (ok 0,8 mm), dzięki czemu mogą być stosowane w technikach druku 3D takich jak SLA (stereolitografia) czy DLP.While 3D printing technologies for plastics and metals are widely used, in the ceramic industry these methods are constantly being improved so that they can be used commercially. Due to the number of proposed solutions, additive manufacturing techniques are considered potentially the best in obtaining ceramic elements with complex shapes. Compared to conventional subtractive fabrication processes, these methods are competitive, in particular in the case of forming single or low-volume products characterized by unique shapes and sizes. Some 3D printing methods use a radical photopolymerization reaction as a mechanism for curing a single printed layer. In this type of techniques, an important step is to develop the composition and prepare a time-stable, homogeneous, photocurable ceramic dispersion. These slurries are usually organic systems and it is necessary to use organic compounds, often harmful to the environment. In this work, the possibility of using aqueous, photocurable ceramic dispersions in the fabrication of complex shaped ceramics from alumina using the digital light processing (DLP) method was examined. The results showed that the developed ceramic slurries are characterized by appropriate rheological properties (viscosity at a shear rate of 10 s-1 does not exceed 0.5 Pa·s) and large cure depths (ca. 0.8 mm), thus they can be used in 3D printing, such as SLA (stereolithography) or DLP

    3D printing of ceramics – possibilities and limitations in additive manufacturing of ceramic parts

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    Dynamiczny rozwój technik formowania przyrostowego, obserwowany na przestrzeni ostatnich lat, świadczy o istniejącej potrzebie na wytwarzanie złożonych i precyzyjnych elementów bez stosowania form odlewniczych. Konieczność dopasowania produktu do indywidualnych potrzeb wymusza powstawanie coraz to nowych technik druku 3D, a także dostosowywanie ich do wytwarzania wyrobów z różnego rodzaju materiałów, m.in. z ceramiki. W artykule przedstawiono zarys historyczny metod druku 3D i ich podział zgodnie z normą ISO/ASTM 52900, a także opisano poszczególne grupy metod oraz przykładowe techniki wchodzące w ich skład. Podczas wyboru techniki formowania dla danego produktu należy wziąć pod uwagę wiele czynników, takich jak rodzaj stosowanego materiału, wymiary produktu czy oczekiwana rozdzielczość. Drukowanie materiałów ceramicznych wciąż stanowi duże wyzwanie dla badaczy, gdyż nie można bezpośrednio przełożyć procesów zachodzących dla polimerów na ceramikę, chociażby ze względu na wysokie temperatury topnienia materiałów ceramicznych. Dodatkowo, w przypadku metod druku 3D wykorzystujących procesy fotoutwardzania (np. w technice DLP (cyfrowego przetwarzania światła), konieczne jest przygotowanie zawiesiny proszku ceramicznego z dodatkiem monomerów i fotoinicjatora. W tej metodzie selektywnie utwardza się powierzchnię zawiesiny warstwa po warstwie przy pomocy światła UV. Niestety, cząstki proszku ceramicznego rozpraszają oraz pochłaniają promieniowanie UV, co znacząco obniża głębokość sieciowania, czyli maksymalną głębokość, na jaką wnika promieniowanie, dostarczając energii niezbędnej do zainicjowania reakcji polimeryzacji. W związku z tym proszek ceramiczny powinien charakteryzować się zbliżoną wartością współczynnika załamania światła do zastosowanej żywicy. Ponadto w przypadku materiałów ceramicznych, ważnym etapem procesu ich otrzymywania, poza formowaniem, jest również spiekanie. Odpowiedni dobór poszczególnych parametrów prowadzenia procesu spiekania, takich jak temperatura spiekania i czas przetrzymania czy szybkość ogrzewania i chłodzenia, jest kluczowy, aby wydrukowane wyroby nie uległy pękaniu i były dobrze zagęszczone. W niniejszym artykule przedstawiono najważniejsze problemy związane z otrzymywaniem ceramiki metodą druku DLP oraz przykładowe ich rozwiązania.The dynamic development of additive manufacturing techniques, observed in recent years, is related to the need for the production of complex and precise elements without the use of casting moulds. Adjusting the product to individual needs forces the development of new 3D printing techniques, as well as adapting them to the production of elements from various types of materials, including ceramics. The article presents a historical outline of 3D printing methods and their division according to the ISO/ASTM 52900 standard, as well as it describes individual groups of methods and exemplary techniques included in them. There are many factors to consider when choosing an appropriate moulding technique, such as the type of material used, product dimensions, and desired resolution. Printing ceramic materials is still a big challenge for researchers because the processes used for polymers cannot be directly transferred into ceramics, for example because of the high melting points of ceramic materials. In addition, in case of 3D printing methods that use photocuring processes (e.g. in the DLP (digital light processing) technique, it is necessary to prepare a suspension of ceramic powder with the addition of monomers and a photoinitiator. In this method, the surface of the slurry is selectively cured layer by layer with UV light. Unfortunately, the ceramic powder particles scatter and absorb UV radiation which significantly reduces the cure depth, i.e. the maximum depth to which the radiation penetrates, providing enough energy to initiate the polymerization reaction. Therefore, the ceramic powder should have a refractive index similar to the used resin. In addition, in the case of ceramic materials, sintering is also an important step. Appropriate selection of individual parameters of the sintering process, such as sintering temperature and dwell time, or the rate of heating and cooling, is crucial to obtain well densified and undefected printed parts. This article presents the most important problems related to obtaining ceramics by DLP printing and exemplary solutions

    Modulatory effects of osthole on lipopolysaccharides-induced inflammation in Caco-2 cell monolayer and co-cultures with THP-1 and THP-1-derived macrophages

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    Lipopolysaccharydes (LPS) are responsible for the intestinal inflammatory reaction, as they may disrupt tight junctions and induce cytokines (CKs) secretion. Osthole has a wide spectrum of pharmacological effects, thus its anti-inflammatory potential in the LPS-treated Caco-2 cell line as well as in Caco-2/THP-1 and Caco-2/macrophages co-cultures was investigated. In brief, Caco-2 cells and co-cultures were incubated with LPS to induce an inflammatory reaction, after which osthole (150–450 ng/mL) was applied to reduce this effect. After 24 h, the level of secreted CKs and changes in gene expression were examined. LPS significantly increased the levels of IL-1β,-6,-8, and TNF-α, while osthole reduced this effect in a concentration-dependent manner, with the most significant decrease when a 450 ng/mL dose was applied (p < 0.0001). A similar trend was observed in changes in gene expression, with the significant osthole efficiency at a concentration of 450 ng/µL for IL1R1 and COX-2 (p < 0.01) and 300 ng/µL for NF-κB (p < 0.001). Osthole increased Caco-2 monolayer permeability, thus if it would ever be considered as a potential drug for minimizing intestinal inflammatory symptoms, its safety should be confirmed in extended in vitro and in vivo studies

    Bioactive Compounds in Aegopodium podagraria Leaf Extracts and Their Effects against Fluoride-Modulated Oxidative Stress in the THP-1 Cell Line

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    Aegopodium podagraria L. (goutweed), a member of the Apiaceae family, is a common perennial plant found all around the world that has been used in folk medicine since antiquity. Goutweed leaves contain polyacetylenes, essential oils, mono- and sesquiterpenes, vitamins, macro- and microelements, and phenolic compounds. In spite of its many health-promoting properties, including antioxidant effects, the plant has not been thoroughly studied. The aim of this study was to investigate the antioxidant properties of different goutweed leaf extracts and their effects on the THP-1 cell line, and also to describe the chemical characteristics of goutweed. Falcarinol and falcarindiol and essential oil were determined by gas chromatography coupled with mass spectrometry. Spectrophotometry was used to measure the total content of polyphenols and antioxidant activity&ndash;by DPPH and FRAP methods. Oxidative stress in THP-1 cells was induced via sodium fluoride. Then, goutweed leaf extracts were added to evaluate their influence on antioxidant potential (ABTS) and the activity of antioxidant enzymes. Confocal microscopy was used to visualise the production of cytoplasmic and mitochondrial reactive oxygen species (ROS) and for in vitro imaging of apoptosis. The ethanol extracts have a high total content of polyphenols, polyacetylenes, and essential oil, as well as high antioxidant potential. The main volatiles represented diverse chemical groups, which are both oxygenated derivatives of sesquiterpenes and monoterpenes. We also demonstrated positive effects of the high antioxidant potential and increased activity of antioxidant enzymes on cell cultures under severe fluoride-induced oxidative stress. Extraction at 80 &#8451; and the use of ethanol as a solvent increased the antioxidant capacity of the extract. The leaves of Aegopodium podagraria may serve as a valuable source of antioxidants in the daily diet and assist in the prevention and treatment of oxidative stress-mediated conditions, e.g., inflammatory conditions, cardiovascular diseases, neurodegenerative diseases, and even obesity
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