Duration of food evacuation in herring, Clupea harengus L., and sprat, Sprattus sprattus (L.)

The fish, which had fed under natural conditions, were kept in tanks and changes in stomach filling with time were observed. Linear relationships between filling and time at various temperatures and different initial filling are described. The relationships serve as a basis for multiple regression equations describing the relationship between food evacuation time and the two factors mentioned above. In the case of herring, separate equations were calculated for mesoplanktonic and makroplanktonic-benthic food

Evolution of vegetable cell size in bioreactor

W pracy badano efekty działania naprężeń burzliwych na agregaty komórek roślinnych w kulturze zawiesinowej prowadzonej w reaktorze okresowym typu Rushtona. Przedstawiono wyniki doświadczalne oraz wyniki modelowania historii populacji agregatów komórek roślinnych w bioreaktorze. Niehomogeniczność burzliwości w skali makro modelowano przy użyciu modeli wielostrefowych, zaś niehomogeniczność w skali mikro modelowano wykorzystując model multifraktalny. Ponieważ niemożliwe jest obecnie bezpośrednie powiązanie złożonej kinetyki wzrostu i rozpadu agregatów komórek roślinnych z modelem CFD ze względu na konieczny, bardzo długi czas obliczeń, dlatego w pracy wykorzystano modelowanie wielostrefowe, a pakiet CFD (Fluent) użyto jedynie do określenia pola przepływów oraz własności burzliwości. Wyniki CFD weryfikowano za pomocą pomiarów LDA. Zaproponowane modele dobrze opisywały ewolucję rozmiaru agregatów komórek roślinnych.The work included investigations on the effects of turbulent stresses on the aggregates of vegetable cells in suspension culture carried out in a Rushton periodic reactor. The findings of experimental investigations and the results of modeling the population history of vegetable cell aggregates in a bioreactor were presented. The turbulence non-homogeneity on a macro-scale was modelled using multi-zone models, whereas the non-homogeneity on a micro-scale was modelled using a multi-fraction model. Due to the necessary long course of calculation it is now impossible to combine directly the complex kinetics of growth and disintegration of vegetable cell aggregates with the CFD model, therefore, the multi-zone modeling was used for the purposes of this experiment, and the CFD (fluent) packet was merely used to determine the flow field and the properties of turbulence. The CFD results were verified by LDA measurements. The proposed models well represented the evolution of vegetable-cell aggregate size

Technology for manufacturing large-size steel castings for applications under extreme operating conditions

Rosnący popyt na odlewy staliwne przeznaczone do zastosowań w temperaturach do minus 40oC skłonił Odlewnię Pioma Sp. z o.o. do podjęcia próby produkcji takich odlewów w oparciu o niskonakładową modyfi kację technologii wytapiania, odlewania oraz obróbki cieplnej odlewów. W pracy na podstawie wyników badań odlewów wytwarzanych ze staliwa w gatunku G18NiMoCr3-6 według stosowanej obecnie technologii, opracowano wytyczne do modyfi kacji technologii w zakresie zmiany składu chemicznego staliwa, sposobu wytapiania staliwa i obróbki cieplnej odlewów. Główne zmiany obejmowały wyeliminowanie ze składu staliwa dodatku tytanu oraz podwyższenie zawartości węgla i pierwiastków stopowych, zmianę sposobu odtleniania staliwa, wprowadzenie modyfikacji wtrąceń niemetalicznych za pomocą drutu rdzeniowego Ca-Si oraz zmieniono wybrane parametry obróbki cieplnej odlewów. Wykonana seria doświadczalnych wytopów staliwa w oparciu o zmodyfikowaną technologię wykazała, że w obecnych warunkach technicznych Odlewni możliwe jest spełnienie wymagań odbiorców, co do właściwości mechanicznych odlewów o grubości do 75 mm, w szczególności udarności równej co najmniej 42 J, dla próbki KV, w temperaturze minus 40°C. W celu spełnienia wymagań odbiorców dla odlewów o większych przekrojach, w oparciu o uzyskane wyniki badań czystości staliwa i właściwości mechanicznych opracowano zalecenia do innowacyjnej technologii rafinacji pozapiecowej ciekłego staliwa.The growing demand for steel castings intended for applications at up to minus 40°C induced the Odlewnia Pioma Sp. z o.o. foundry to make an attempt to manufacture such castings based on a low-cost modification of technology for melting, casting and heat treatment of castings. In this paper, the guidelines for technology modifications with regard to the change in cast steel chemical composition, cast steel melting method and heat treatment of castings were developed based on results of investigations for castings manufactured from G18NiMoCr3-6 cast steel in accordance with the current technology. The main changes included the elimination of titanium additive from the cast steel composition and increase in the contents of carbon and alloying elements, a change in the cast steel deoxidation method, introduction of modifications to non-metallic inclusions by means of Ca-Si fl ux-cored wire, and selected casting heat treatment parameters were changed. The series of experimental cast steel melts manufactured using the modified technology have revealed that it is possible to meet the buyers’ requirements for mechanical properties of castings with thickness of up to 75 mm, in particular impact strength of at least 42 J, for KV sample at minus 40°C under the present technical conditions of the Foundry. To meet the buyers’ requirements for castings with higher cross-sections, the recommendations on innovative technology for secondary refining of liquid cast steel were developed based on obtained results of investigations of cast steel purity and mechanical properties

Investigation of liquid steel decarburisation process in a ladle using blowing with argon and a mixture of oxygen and argon

Przedstawiono koncepcję i instalacje doświadczalne do odwęglania stali w kadzi o dużej pojemności (50 t) z przedmuchiwaniem kąpieli argonem przez hybrydową kształtkę gazoprzepuszczalną w dnie oraz w kadzi o małej pojemności (1 t) z wdmuchiwaniem do ciekłego metalu mieszaniny tlen - argon lancą od góry. Przeprowadzone na tych instalacjach próby doświadczalne wykazały dla pierwszej instalacji zmniejszenie zawartości węgla poniżej 0,02% i fosforu poniżej 0,003%, a w drugiej instalacji, możliwość elastycznego odwęglania kąpieli do zawartości węgla mniejszej niż 0,03%. Przedstawiono technologiczne scenariusze zastosowania zbadanych sposobów odwęglania stali w kadzi.The article presents the concept and experimental installations for decarburisation of steel in a large capacity ladle (50 t) with blowing the bath with argon through a gas-permeable hybrid fitting and in a small capacity ladle (1 t) with injection of an oxygen – argon mixture with a lance into liquid metal from above. For the first installation, the experimental tests showed a reduction in the carbon content below 0.02% and phosphorus below 0.003%, and in the second installation – the possibility of flexible decarburisation of the bath to a carbon content of less than 0.03%. Technological scenarios of the use of the investigated decarburisation methods of steel in a ladle are presented in the article

Huperzine alkaloids from Australasian and southeast Asian Huperzia

Context: The pharmaceutical alkaloid huperzine A (HupA), currently used in herbal supplements and medicines worldwide, is predominantly sourced from the Chinese lycopod Huperzia serrata (Thunb. ex Murray) Trev. (Lycopodiaceae), which on average contains only 0.08mg HupA g−1 dry weight, and is experiencing a rapid decline in China due to over-harvesting.\ud \ud Objective: To find a high-yielding, natural source of HupA and/or the related huperzine B (HupB) that could potentially be used as the starting material in a commercial propagation program.\ud \ud Materials and methods: We surveyed 17 Huperzia species (15 indigenous to Australia and southeast Asia) for their foliar HupA and HupB concentrations. We also studied intra-specific variation for the huperzines in four species that were available in sufficient numbers, and determined tissue-specific accumulation in larger specimens.\ud \ud Results: HupA was detected in 11 Australasian and southeast Asian species, with eight also containing HupB, albeit at much lower concentrations. A H. elmeri (Herter) Holub plant from the Philippines had one of the highest HupA concentrations recorded (1.01mg g−1 dry wt) and it also had the highest HupB content of all plants surveyed (0.34mg g−1 dry wt). Intra-specific HupA and HupB concentrations were extremely variable, and at the intra-plant level, reproductive strobili were found to accumulate the highest HupA concentrations.\ud \ud Discussion and conclusion: Select Huperzia species from Australia and southeast Asia have potential as the starting material for establishing commercial HupA plantations, but the high intra-specific variability observed suggests that detailed screening is needed to isolate high huperzine-yielding individuals

Tree Growth and Climate Relationship: Dynamics of Scots Pine (Pinus Sylvestris L.) Growing in the Near-Source Region of the Combined Heat and Power Plant During the Development of the Pro-Ecological Strategy in Poland

Since the 1990s, the emission of pollutants was reduced in a majority of Polish and developing country factories whereas the level of energy production was similar to that prior to the 1990s. The conifer investigated in this study has grown for many years under the stress of industrial pollution. Despite this, the trees are preserved, to a large extent, sensitive to the natural climatic factors. We present a complex analysis of the climatic (sunshine, temperature, precipitation, humidity, and wind circulation) and anthropogenic factors influencing the radial increment dynamics of Scots pine (Pinus sylvestris L.) growing in the vicinity of the combined heat and power station in Łaziska (Poland). We analyzed the spatiotemporal distribution of growth reductions, the depth of reduction with respect to the distance from the emitter, the relationship between tree growth and climate during the industry development period and during proecological strategy application . Samples of carbon isotopic composition in pine needles from 2012 to 2013 were additionally determined. Pines series of 3 positions indicate that they have a similar sensitivity to most climatic elements of the previous and given year, but there is also a different rhythm between the studied populations of incremental growth of pines. The causes of diversity are due to the different types of habitat (site types) and industrial pollution. The variation in carbon stable isotopic composition in pine needles was connected with an increase of CO(2)