Effect of Propeller Slipstream on Wing and Tail

The results of wind tunnel tests for the determination of the effect of a jet on the lift and downwash of a wing are presented in this report. In the first part, a jet without rotation and with constant velocity distribution is considered - the jet being produced by a specially designed fan. Three-component, pressure distribution, and downwash measurements were made and the results compared with existing theory. The effect of a propeller slipstream was investigated in the second part. In the two cases the jet axis coincided with the undisturbed wind direction. In the third part the effect of the inclination of the propeller axis to the wing chord was considered, the results being obtained for a model wing with running propeller

Contribution to the Problem of Airfoils Spanning a Free Jet

After a brief discussion of the work done up to now on an unwarped wing of constant chord spanning a free jet, the computation of the circulation and lift distribution for different forms of warped wings spanning rectangular and circular jets was carried out. The computed values are compared with test values and the agreement is found to be good. The effect of placing the wing eccentrically is slight and may be applied as a correction factor to the data obtained for wing placed in middle of jet

Investigation of Boundary Layers on an Airplane Wing in Free Flight

This report describes the equipment and method developed for recording the boundary layers on the surface of an airfoil in free flight. The results are in close agreement with the wind-tunnel tests of other experimenters. The intensity of the turbulent boundary layer, even at the much higher Reynolds Numbers reached, is determinable with Gruschwitz's formulas, although it was impossible to definitely establish a direct relationship between the turbulent boundary layer and the Reynolds Number within the limits of the obtained accuracy. The observations on the transition from laminar to turbulent flow check with previous wind-tunnel tests and calculations

An Airfoil Spanning an Open Jet

Proceeding from the fundamental problem on the mutual relation of a wing and free boundaries the distribution of the circulation is determined for an airfoil spanning an open jet of rectangular section at different aspect ratios, and then for an open jet of circular section. The solution is obtained by means of a Fourier series and computations have been performed for different values of the variables. The second part describes the experiments performed for the purpose of proving the theory. The results confirm the theory. In conclusion it defines the induced drag of a wing extending across an open jet and compares it with the drag of a monoplane having a span equal to the jet width at equal total lift

Reduction of lift of a wing due to its drag

This analysis computes for a predetermined airfoil and given Reynolds Number the course of the "displacement thickness," i.e., the course of the layer by which the streamlines of the potential flow are pushed away from the wing through the frictional layer. The result is, to a certain extent, a new wing contour

Study of metabolite profiles in winter wheat cultivars induced by Fusarium infection

The aim of this study was to determine the profile of fungal metabolites and antioxidant substances from plants on a representative population of wheat cultivars grown in Poland. Tests were conducted on grain of 23 wheat cultivars in three experimental variants: natural infection (control), chemical crop protection, and artificial inoculation with the fungi F. graminearum and F. culmorum. Grains were analysed in terms of infection rate, mycotoxin, ergosterol, free and bound phenolic acid content, as well as antioxidant capacity. Calculated Fusarium head blight index (FHB index) ranged from 0% to 24% in the control, from 0% to 95% after inoculation and from 0 to 3% following chemical crop protection treatments. The highest concentration of ergosterol was detected in seeds from inoculated plots, with a mean value of 26.69 mg/kg. The highest mean concentration calculated for total toxin content was recorded after inoculation (7.833 mg/kg). The mean value for ferulic acid for inoculated samples resulted 2574 mg/kg, while for chemically protected samples 1158 mg/kg was obtained. Based on of discriminant analysis genotypes can be separated for inoculation 100%, for chemical crop protection 95%, and for natural infection 90%. Amongst 12 analysed phenolic acids the highest discrimination power was found for gallic acid, 4-hydroxybenzoic acid and vanillic acid

Polyphenols: A concise overview on the chemistry, occurrence, and human health

This review gives an updated picture of each class of phenolic compounds and their properties. The most common classification implies the subdivision of phenolics in two main groups: flavonoids (e.g., anthocyanins, flavanols, flavanones, flavonols, flavonones, and isoflavones) and non-flavonoids (e.g., phenolic acids, xanthones, stilbens, lignans, and tannins) polyphenols. The great interest in polyphenols is associated with their high potential application for food preservation and for therapeutic beneficial use. The relationship between polyphenol intake and human health has been exploited with special reference to cardiovascular diseases, hypertension, diabetes, metabolic syndrome, obesity, and cancer. The use of current existing databases of bioactive compounds including polyphenols is described as key tools for human health research.info:eu-repo/semantics/publishedVersio

Content of ergosterol in food products of cereals

Zawartość biomasy grzybowej wpływa w istotny sposób na ocenę jakości produktów spożywczych. W pracy przedstawiono zawartość biomarkera biomasy grzybowej (ergosterolu-ERG) w ziarnie zbóż, produktach śniadaniowych zawierających otręby oraz płatki zakupione w sieci sklepów detalicznych na terenie miasta Poznania w roku 2008, jak również w mąkach, a także w produktach po przemiale laboratoryjnym. Największą średnią zawartość ERG stwierdzono w otrębach owsianych - wynosiła ona 30,71 mg/kg, natomiast najmniejszą spośród analizowanych otrąb oznaczono w otrębach pszennych - 9,98 mg/kg. Spośród płatków najwięcej ERG stwierdzono w płatkach owsianych - 8,04 mg/kg, a najmniej w pszennych - 0,97 mg/kg. Produkty zawierające dodatki w postaci suszu owocowego zawierały większą ilość ERG niż analogiczne produkty bez dodatków. Przebadano również mąki żytnie, jęczmienne, owsiane oraz pszenne. Porównano zawartość ERG w mąkach w stosunku do otrąb stwierdzając, że zawartość tego metabolitu jest porównywalna we wszystkich zbożach i jest mniejsza w mące średnio o około 97 %. Zawartość tego metabolitu w otrębach była większa w stosunku do ziarna niepoddanego obróbce i wynosiła około 50 %. Obok ww. produktów przemiału badano również zawartość ERG w ziarnie pobranym także w 2008 r. z silosów zbożowych. Najwięcej ERG stwierdzono w ziarnie owsa, najmniej w ziarnie pszenicy odpowiednio 16,11 mg/kg i 4,13 mg/kg.The content of fungal biomass essentially impacts the quality assessment of food products. In this paper, the content of ergosterol (ERG) was presented, i.e. of a fungal biomass bio-indicator in cereal grain, in breakfast foodstuffs containing bran and flakes that were purchased in shops of a retail network in Poznań in 2008, as well as in flours and in the products milled in a laboratory. The highest mean content of ERG was found in oat bran: 30.71 mg/kg, whilst the lowest ERG content, among all the bran types analysed, was reported in wheat bran: 9.98 mg/kg. Among all the corn flakes tested, the oat flakes were reported to contain the highest amount of ERG: 8.04 mg/kg, and the wheat flakes - the lowest: 0.97 mg/kg. The products containing additives in form of dehydrated fruits had a higher amount of ERG than the analogous products without additives. The rye, barley, oat, and wheat flours were also investigated. The content of ERG in the flours and in the bran tested was compared; it was found that the content of this metabolite was comparable in all the cereal types, and, as for the flours, it was lower by about 97 %. The content of this metabolite in the bran tested was higher if compared with the non-processed grain, and the ERG concentration was higher by about 50 %. In addition to the above mentioned milled products, the content of ERG was also analyzed in the grain gathered in 2008 and stored in cereal storage silos. Here, the highest ERG concentration was found in the oat grain: 16.11 mg/kg, and the lowest in the wheat grain: 4.13 mg/kg

Growth dynamics of moulds and formation of mycotoxins during storage of bread

Celem niniejszych badań było badanie zmian zawartości mikotoksyn z grupy trichotecenów oraz mikoflory podczas przechowywania chleba. Analizowano 18 prób, które przechowywano w trzech różnych warunkach wilgotności względnej powietrza oraz temperatury przez 120 godzin. Próby pobierano co 6 godzin. Ilościowe oznaczenie mikoflory wykonano dwoma metodami: klasyczną metodą mikrobiologiczną oznaczania ilości JTK (jednostek tworzących kolonie grzybów mikroskopowych) oraz chemiczną analizą stężenia ergosterolu (ERG). Na podstawie uzyskanych wyników stwierdzono istotny wpływ wilgotności oraz temperatury na tworzenia mikotoksyn oraz wzrost grzybów mikroskopowych. Dynamikę wzrostu pleśni oraz tworzenia mikotoksyn opisano wielomianami trzeciego stopnia.The aim of these investigations was to determine changes in the concentration of mycotoxins from the group of trichothecenes and mycoflora during storage of bread. 18 samples of bread were analyzed. Samples were stored in three different conditions of air humidity and temperature trough 120 h. Samples were collected in 6 h. Level of mycoflora was analyzed by classic microbiologycal metod CFU (colony forming units) and ergosterol analysis. On the basis of conducted that conditions of air humidity and temperaturehas is significant growth dynamics of microscopic fungi and their formation of mycotoxins from the group of trichothecenes during storage of bread

Contamination of wheat grain with microscopic fungi and their metabolites in Poland in 2006–2009

Microscopic fungi are microorganisms commonly found in cereal products. Pathogens of cereals colonising kernels are responsible, among other things, for deterioration of the technological value of grain. However, the greatest threat is posed by mycotoxins produced by toxin-forming strains of these microorganisms. The aim of the present study was to determine the level of contamination with microscopic fungi and mycotoxins from the group of trichothecenes in wheat grain from Poland in a 4-year cycle. In the period 2006–2009, studies were conducted on the content of fungal metabolites (ergosterol [ERG] and type A and B trichothecenes) and the content of microscopic fungi expressed in colony-forming units (CFU) in wheat grain. A total of 129 grain samples were examined. Analysed wheat samples had similar contents of both the investigated fungal metabolites and levels of microscopic fungi. Contents of microscopic fungi were low. Concentration of ERG, on average, was 2.64 mg/kg, while in colony forming units this value ranged from 101 CFU/g to over 103 CFU/g. The total concentration of type A and B trichothecenes was also low and within the 4 years of the investigation did not exceed 0.062 mg/kg. Concentration of DON did not exceed 1,250 μg/kg, established as safe in grain for human consumption, in any of the tested samples. For the results collected in the years 2006–2009 and presented in this paper, correlations were calculated between the amount of mycoflora and analysed metabolites in 3 possible combinations: 0.7096 for ERG/total toxin concentration, 0.6086 for ERG/log CFU/g, and 0.4016 for the concentration of total toxins/log CFU/g. Highly significant correlations between the content of trichothecenes and the concentration of ERG indicate that the level of this metabolite is closely related to the content of mycotoxins in grain