Wyniki wyszukiwania - Biblioteka Nauki

1

Adhesion, growth and differentiation of human osteoblast-like cells on thermally oxidized Ti and TiNb substrates

100%

Bacakova L. , Vandrovcova M. , Jirka I. , Novotna K. , Stary V.

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tom Vol. 16, no. 122-123 spec. iss.

75--76

EN

Metallic materials are essential for construction of load-bearing bone implants, such as replacements of hip, knee and other joints. For these applications, modern materials used in advanced tissue engineering, e.g. resorbable porous or fibrous polymeric and ceramic scaffolds are mechanically insufficient, even if these materials enable the ingrowth of bone cells and bone tissue formation. Therefore, searching for new metallic materials and their surface modifications improving their biocompatibility and osseointegration is still desirable. As first metallic materials for bone implantation, AISI 316L stainless steel and Co-Cr alloys were used. In the 1950’s, the Ti-6Al-4V alloy was developed. These materials are still frequently used for construction of implants because of their relatively low price [1]. However, these materials are biomechanically incompatible with the bone tissue, because their Young’s modulus is markedly higher (110-220 GPa) than that of the bone (10-40 GPa). Implants with high stiffness take over a considerable part of load from the bone. This phenomenon, referred as “stress-shielding effect”, can then cause the bone resorption and loosening of the implant [1]. Also chemical compositions of the mentioned metallic materials limit their biocompatibility, because they contain harmful elements as V, Al, Co and Cr, which can act as cytotoxic, catabolic, immunogenic or even carcinogenic agents [2,3], and can also cause serious neurological problems [4]. Due to these adverse reactions, new types of Ti-alloys have been developed, namely low-rigidity β-type Ti alloys, containing non-toxic and non-allergenic elements (Nb, Ta, Zr etc.) and having good mechanical properties and workability [4,5]. The goal of this study was to evaluate the adhesion, growth and differentiation of osteoblast-like MG-63 and Saos-2 cells on titanium-niobium alloys after their surface modification by thermal oxidation at two different temperatures (165°C and 600°C). Pure titanium (treated at 165°C and 600°C) and polystyrene culture dishes (PS) were used as control materials. Possible immune activation of the cells was tested by the levels of TNF-alpha secreted to the cell culture media by murine macrophage-like RAW 264.7 cells cultured on the tested materials. On samples treated at 165°C, the number of initially adhered MG-63 and Saos-2 cells was on an average higher on TiNb than on Ti or PS. On day 3 after seeding, the trend of the cell numbers remained similar, with the highest cell density found on TiNb. Similar results were obtained on samples treated at 600°C, where the difference in cell number between TiNb and Ti samples became more apparent. This cell behavior could be attributed to a less negative zeta potential on TiNb samples. In samples treated at 165°C, the zeta potential of TiNb surfaces was on the average less negative than on Ti surfaces, but this difference was not significant. However, in samples treated at 600°C, this difference became much more pronounced, which was probably due to the formation of T-Nb2O5 phase on the surface of the TiNb samples. This phase was of a crystalline structure, while at 165°C, the structure of Nb2O5 was amorphous. In addition, both Ti and TiNb samples treated at 600°C contained rutile, while the samples treated at 165°C contained anatase in their surface layer. It has been shown that rutile films deposited on PEEK enhanced the adhesion and growth of osteoblasts more than anatase films [6]. This phenomenon was explained by an increase in the material surface wettability, and particularly to the presence of –OH- groups on the rutile films. The expression of collagen I and osteocalcin, i.e. an early and late marker of osteogenic cell differentiation, respectively, was higher on Ti than on TiNb samples, and this difference was more apparent in samples treated at 165°C. At the same time, no considerable immune activation of the cells on all tested samples was found. The production of TNF-α by RAW 264.7 cells was very low in comparison with cells grown in the presence of bacterial lipopolysaccharide, and also significantly lower than on untreated samples. These results indicate that TiNb substrates increased the proliferation of human bone cells, while pure Ti rather supported the cell differentiation. The effect on cell proliferation was more apparent in samples treated at the higher temperature (600°C), while the effect on cell differentiation was more pronounced at the lower temperature (165°C). None of the tested samples induce significant cell proinflammatory activation. Thus, all tested samples are suitable as carriers for bone cells; only an appropriate application (i.e., requiring either proliferation or quick differentiation of osteogenic cells) should be selected.

2

The impact of unmodified graphene - based substrates on basic properties of human umbilical cord-derived mesenchymal stem cells in vitro

100%

Noga S. , Moździerz A. , Sekuła M. , Karnas E. , Jagiełło J. , Madeja Z. , Lipińska L. , Zuba-Surma E.

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tom Vol. 21, no. 148

83

3

Controlling rate of delivery of applicators at the harvest of substrates biogasworks : preliminary issues

100%

Borowski B.

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tom Vol. 7, no 3

17-22

EN

At the paper preliminary issues concerning applications of preparations preserving to silages were introduced. Such silages can be used as forage of animals and substrates of the biogasworks. During the harvest of green fodder to silages getting an end product of the better quality is one of more important problems.It is possible to obtain it using additions facilitating ensilage. Using them allows also for the improvement of the quality of the long preserved silage. One should aspire to it to get regular distributing preparation in the entire capacity of the silo. In the course of the application losses of preparation should be minimal.

4

Effectiveness of electron beam irradiation in the control of Rhizoctonia solani

88%

Orlikowski L. B. , Gryczka U. , Ptaszek M. , Migdał W.

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tom Vol. 57, No. 4

551-554

EN

Effectiveness of electron beam irradiation was evaluated against Rhizoctonia solani, which is one of the most dangerous soil-borne pathogen, causing stem base and root rot of many horticultural plants. Treatment of in vitro cultures with 0.5 kGy significantly inhibited the pathogen's growth and the spread of necrosis on chrysanthemum leaf blades inoculated with the irradiated cultures. Application of e-beam irradiation for peat disinfection resulted in a two-fold decrease rot development in chrysanthemum stem at a dose of 5 kGy and complete inhibition at 10 kGy. For the elimination of R. solani from composted pine bark and its mixture with peat, irradiation of both substrates with 15 kGy was necessary.

5

The concept of a proconsumer hydro power plant with a special bearing for the main shaft

88%

Mikuła J. , Mikuła S. , Strzelecki S.

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2022

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tom No. 1

15--18

EN

This paper presents the idea of economical, proconsumer hydro power unit. The described hydro power unit allows the generating of electric energy for own needs. However, the overproduction of power can be supplied to the state energy system. The hydropower units of small output that use the local rivers and creeks should additionally support the operation of wind power units. The design of such units should consider such restriction as, among others, cyclic operation that is characterized by often starts and stops. Proconsumer hydropower units have to assure a fast start, respective energy efficiency and a very high durability. These features can be obtained by means of proper design of the journal bearing of turbine main shaft. Hybrid bearing system connecting the journal bearing with the rolling bearing assures the decrease in the start power losses, good durability and reliability of proposed system of hydropower unit. Very important feature of this system is the application of the rolling bearing during the operation. Such bearing allows the decrease in the start time and protects against an insufficient load capacity of lubricating oil film. It is possible to apply the emulsions oil-water as well as clean water as lubricant, too.

PL

Artykuł przedstawia koncepcję ekonomicznej, prosumenckiej siłowni wodnej. Omówiona energetykę prosumencka pozwala użytkownikom na wytwarzanie energii elektrycznej na własne potrzeby. Przewidziano możliwość przekazywania nadmiaru energii do krajowej sieci energetycznej. Uzupełnieniem wiatrowej energetyki prosumenckiej może być wykorzystanie małych siłowni wodnych wykorzystujących lokalne zasoby rzek i strumieni. Konstrukcja siłowni wodnych dla indywidualnych potrzeb uwzględnia szereg ograniczeń w tym okresową pracę charakteryzującą się częstymi rozruchami i zatrzymaniami. Prosumenckie siłownie wodne muszą zapewniać szybki rozruch, odpowiednią sprawność energetyczną oraz wysoką niezawodność. Cechy te może zapewnić odpowiednie rozwiązanie łożyska ślizgowego wału głównego. Hybrydowy układ łożyskowania łączący łożyskowanie ślizgowe z tocznym zapewnia zmniejszenie oporów rozruchowych, trwałość i niezawodność proponowanego układu siłowni wodnej. Ważną cechą proponowanego rozwiązania konstrukcyjnego jest zastosowanie wspomagającego łożyska tocznego, które automatycznie włączane jest do pracy podczas wybiegu. Łożysko toczne zapewnia zmniejszenie czasu rozruchu i zabezpiecza przed pracą w warunkach niedostatecznej nośności filmu smarowego. Możliwe jest również zastosowanie emulsji olejowo-wodnych i czystej wody.

6

Role of Substrates Used for Green Roofs in Limiting Rainwater Runoff

88%

Baryła A. , Karczmarczyk A. , Bus A.

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tom Vol. 19, nr 5

86--92

EN

The retention of rainwater is one of the main functions of green roofs in urban areas. One of the elements influencing the variability of rainwater retention on green roofs is the configuration of the roof, i.e. the combination of drainage and vegetation layers and plants. In the article, laboratory studies regarding the influence of the vegetation layer of the green roof on the retention of rainwater were carried out, and the influence of changes in the initial moisture content in extensive and intensive substrates on retention were compared. The analysis of seven randomly selected substrates showed that the runoff coefficients range from 0.59 to 0.71. In the case of the retention, statistically significant differences were observed in terms of the rainfall volume as well as the initial moisture content.

7

Signalling: basics and evolution.

75%

Robert J.P Williams

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2004

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tom 51

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nr 2

281-298

EN

Signalling concerns the transfer of information from one body, a source, to another, a receiver in order to stimulate activity. The problem arises with the word information. It is defined as what is transferred in a sequence of things, say between people, e.g. words or signs. The idea of signalling between people is then obvious but it is not clear in cell biology. Information transfer, signalling, is required for the organisation of all cellular activity but we must ask what is transferred and how is it transmitted and received? Sometimes it is assumed that all information, i.e. organisation in a cell, is represented in the DNA sequence. This is incorrect. We shall show that the environment is a second source of information concerning material and energy. The receiving party from both DNA and the environment is general metabolism. The metabolism then signals back and sends information to both DNA and uptake from the environment. Even then energy is needed with machinery to send out all signals. This paper examines the way signalling evolved from prokaryotes through to man. In this process the environmental information received increased to the extent that finally the brain is a phenotypic as much as a genotypic organ within a whole organism. By phenotypic we mean it is organised by and interactive with information from the environment.

8

Projektowanie warstw ochronnych i podłoży kolejowych budowli ziemnych wzmocnionych geotekstyliami

63%

Zelek Z.

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tom Z. 149

37-52

PL

Artykuł przedstawia metody projektowania warstw ochronnych i podłoży dróg kolejowych wzmocnionych geotekstyliami. Charakteryzuje rolę geotekstyliów we wzmocnieniu konstrukcji oraz zwiększeniu trwałości i niezawodności drogi kolejowej, dzięki odpowiedniemu rozłożeniu naprężeń od taboru i zapewnieniu właściwej filtracji wód opadowych. Przytacza podstawowe wymagania, którym powinny odpowiadać geotekstylia oraz metody projektowania wykorzystujące moduł odkształcenia gruntów jako kryterium nośności. Podaje przykłady nomogramów, ułatwiających prace projektowe. W podsumowaniu podkreśla potrzeby odpowiedniego projektowania wzmocnionych podłoży w zależności od rodzaju gruntów, materiałów i warunków eksploatacyjnych.

EN

The paper presents methods for the design of sub layers and geotextiles reinforced track beds of railway lines. It describes the part of geotextiles in the reinforcement of a structure and improvement in durability and reliability of a railway line due to right distribution of rolling stock generated stress as well as proper filtration of precipitation water. Basic requirement for geotextile materials are given as well as design methods using the modulus of soil compression as carrying capacity criterion. Examples of nomograms for easier design work are given. In the Summary, the need for correct design of reinforced track beds depending on the type of soil, materials used and operating conditions is emphasized.

9

Role of drainage layer on green roofs in limiting the runoff of rainwater from urbanized areas

63%

Baryła A. M.

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tom no. 41

12--18

EN

Green roofs play a significant role in sustainable drainage systems. They form absorbent surfaces for rainwater, which they retain with the aid of profile and plants. Such roofs therefore take an active part in improving the climatic conditions of a city and, more broadly, the water balance of urbanized areas. One of the factors influencing the hydrological efficiency of green roofs is the drainage layer. In the article, column studies were carried out under field conditions involving the comparison of the retention abilities of two aggregates serving as the drainage layer of green roofs, i.e. Leca® and quartzite grit. The average retention of the substrate was 48%; for a 5 cm drainage layer of Leca® retention was 57%, for a 10 cm layer of Leca average retention was 61%. For a 5 cm layer of quartzite grit average retention was 50%, for 10 cm layer of quartzite grit 53%. The highest retention was obtained for the column with the substrate and 10-centimeter layer of Leca®. At the same time, it was shown that Leca® is a better retention material than quartzite grit. The initial state of substrate moisture content from a green roof appears to be a significant factor in reducing rainfall runoff from a green roof; the obtained values of initial moisture content made for a higher correlation than the antecedent dry weather period.

PL

Istotną rolę w zrównoważonych systemach drenażu odgrywają zielone dachy. Są powierzchniami chłonnymi w odniesieniu do wód opadowych, które retencjonują w profilu i za pomocą roślin. Biorą zatem czynny udział w poprawie warunków klimatycznych miasta, a szerzej bilansu wodnego terenów zurbanizowanych. Jednym z czynników wpływających na wydajność hydrologiczną zielonych dachów jest warstwa drenażowa. W artykule przedstawiono wyniki badań kolumnowych przeprowadzonych w warunkach polowych, w których porównano retencyjność dwóch kruszyw wykorzystywanych jako warstwa drenażowa na zielonych dachach – keramzytu i grysu kwarcytowego. Średnia retencja substratu wyniosła wyniosła 48%, dla 5 cm warstwy drenażowej z Leca® wyniosła 57%, dla warstwy 10 cm średnia retencja wyniosła 61%. Dla grysu kwarcytowego średnia retencja wyniosła dla 5 cm warstwy drenażowej 50%, dla 10 cm warstwy drenażowej 53%. Największą retencję uzyskano w kolumnie z substratem i 10-centymetrową warstwą keramzytu. Wykazano, że keramzyt jest lepszym materiałem retencyjnym niż grys kwarcytowy. Początkowy stan wilgotności podłoża z zielonego dachu wydaje się być istotnym czynnikiem w redukcji odpływu wód opadowych z dachu zielonego. Uzyskane wyniki wilgotności początkowej dały silniejszą korelację niż czas pomiędzy opadami.

10

Energetic and economic efficiency of agricultural biogas plant working with different substrates

63%

Dach J.

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tom Vol. 61, nr 3

72--76

EN

Ensuring the profitability of working biogas plants is a key factor for the development of biogas market. Apart from the price obtained for sold electricity, the substrates are the most important factor, particularly the ratio of their acquisition cost to methane efficiency. Thus, the objective of this paper was energy and economic analysis of the typical biogas plant with a capacity of 1 MWe working in new, favorable market situation (higher prices for blue certificates and in auction system) and using different biomass and waste substrates. After biogas efficiency tests and economic calculations of 4 different agricultural and waste substrates (maize silage, beet pulp, refood and chicken manure) it has been stated that the chicken manure was the most energy effective, just after maize silage. However chicken manure is 5 times cheaper. However, refood is the most profitable substrate for biogas plant working in both variants (certificates and auctions), and slightly less favorable - chicken manure. It is related to the best price - methane efficiency ratio, since the adoption of refood for biogas plants receives payment in the amount of 20 PLN per ton. In vast majority of analyzed substrates, investment in agricultural biogas plant is now becoming a very profitable venture, because annual profit before tax fluctuated in the range of 1-4 million PLN.

PL

Najważniejszym czynnikiem dla rozwoju rynku biogazowego jest zapewnienie opłacalności pracy biogazowni. Poza ceną uzyskaną za sprzedawaną energię elektryczną, najważniejszym czynnikiem są substraty, a zwłaszcza stosunek ich kosztu pozyskania do wydajności metanowej. Stąd celem niniejszej pracy była analiza energetyczna i ekonomiczna typowej biogazowni o mocy 1 MWe pracującej w nowej, korzystnej sytuacji rynkowej (wyższe ceny za błękitne certyfikaty oraz w systemie aukcyjnym) i wykorzystujące różne substraty biomasowe i odpadowe. Po przeprowadzeniu badań i obliczeń dla 4 różnych substratów rolniczych i odpadowych (kiszonka z kukurydzy, wysłodki buraczane, refood i obornik kurzy) stwierdzono, że najbardziej efektywny energetycznie był obornik kurzy obok kiszonki z kukurydzy. Obornik kurzy jest jednak 5 razy tańszy w pozyskaniu. Z kolei najbardziej opłacalnym substratem dla biogazowni rolniczej pracującej w obu wariantach (certyfikatów jak i aukcji) jest refood, nieco mniej korzystnym obornik kurzy. Wynika to z najkorzystniejszego stosunku ceny do wydajności metanowej bowiem za przyjęcie refood do biogazowni otrzymuje się dopłatę w wysokości 20 zł za tonę. W zdecydowanej większości analizowanych substratów inwestycja w biogazownię rolniczą staje się obecnie bardzo opłacalnym przedsięwzięciem, bowiem roczny zysk przed opodatkowaniem wahał się w zakresie 1-4 mln zł.

11

New Trends in Substrates and Biogas Systems in Poland

63%

Marks S. , Dach J. , Fernandez Morales F. J. , Mazurkiewicz J. , Pochwatka P. , Gierz Ł.

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2020

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tom Vol. 21, nr 4

19--25

EN

The amendment to the Polish Renewable Energy Act creates great opportunities for the development of the biogas market in Poland. Years of experience in biogas production in Western Europe and the development of biogas installations in Poland indicate the requirement to look for alternative substrates to those produced from dedicated crop production (mainly maize silage). Feasible solutions include the use of biodegradable waste from agriculture or industry as well as municipal landfill sites. The usage of these substrates in the methane fermentation process offers low cost, high biogas production and the safe management of biowaste. The arguments for using them in biogas installations are persuasive. This article presents new approaches of biogas plant installation solutions which allows for the effective fermentation of biowaste from animal and vegetable production, from the agro-food industry and from municipal waste.