Backscattering of Electrons from Complex Structures

The backscattering of electrons from complex targets (for example, metal layer on a semi-infinite substrate with a polymer resist film above) has been studied both theoretically and experimentally. The experimental structures were exposed with an electron beam in a spot mode . The experimental observations of developed disc radius vs. exposure time and metal layer thickness support the simple theory of scattering in such structures. The theory assumes that the backscattering causes enlarging of the exposed area by a constant value. This value is derived from the proposed scattering model based on the Archard\u27s and Kanaya and Okayama\u27s diffusion theories. The radial exposure intensity distribution introduced by the electron beam has been approximated by a Gaussian function

On temperature- and space-dimension dependent matter agglomeration in a mature growing stage

Model matter agglomerations, with temperature as leading control parameter, have been considered, and some of their characteristics have been studied. The primary interest has been focused on the grain volume fluctuations, the magnitude of which readily differentiates between two commonly encountered types of matter agglomeration/aggregation processes, observed roughly for high- and low-density matter organizations. The two distinguished types of matter arrangements have been described through the (entropic) potential driving system. The impact of the potential type on the character of matter agglomeration has been studied, preferentially for (low density) matter agglomeration for which a logarithmic measure of its speed has been proposed. A common diffusion as well as mechanical relaxation picture, emerging during the mature growing stage, has been drawn using a phenomenological line of argumentation. Applications, mostly towards obtaining soft agglomerates of so-called jammed materials, have been mentioned

Ionic liquids at electrified interfaces

Until recently, “room-temperature” (<100–150 °C) liquid-state electrochemistry was mostly electrochemistry of diluted electrolytes(1)–(4) where dissolved salt ions were surrounded by a considerable amount of solvent molecules. Highly concentrated liquid electrolytes were mostly considered in the narrow (albeit important) niche of high-temperature electrochemistry of molten inorganic salts(5-9) and in the even narrower niche of “first-generation” room temperature ionic liquids, RTILs (such as chloro-aluminates and alkylammonium nitrates).(10-14) The situation has changed dramatically in the 2000s after the discovery of new moisture- and temperature-stable RTILs.(15, 16) These days, the “later generation” RTILs attracted wide attention within the electrochemical community.(17-31) Indeed, RTILs, as a class of compounds, possess a unique combination of properties (high charge density, electrochemical stability, low/negligible volatility, tunable polarity, etc.) that make them very attractive substances from fundamental and application points of view.(32-38) Most importantly, they can mix with each other in “cocktails” of one’s choice to acquire the desired properties (e.g., wider temperature range of the liquid phase(39, 40)) and can serve as almost “universal” solvents.(37, 41, 42) It is worth noting here one of the advantages of RTILs as compared to their high-temperature molten salt (HTMS)(43) “sister-systems”.(44) In RTILs the dissolved molecules are not imbedded in a harsh high temperature environment which could be destructive for many classes of fragile (organic) molecules

Oznaczanie cholesterolu w tluszczu mlekowym metoda chromatografii gazowej

The GC-method for determination of triacylglycerol composition in milk fat was found applicable for quantitation of cholesterol in milk, cream and butter providing that dotriacontane internal standard was introduced to the sample prior the separation. The standard deviation of cholesterol content was 9.11 mg/100 g fat at the level of 200 mg/100 g fat. The average recovery of cholesterol from butter-isolated fat was 94.3% within the range of 75- 500 mg/100 g fat. Similar contents of cholesterol in milk (239.24±42.63 mg/100 g), cream (243.42±26.83 mg/100 g) and butter (245.24 ±33.73 mg/100 g) wer,: found. The highest variation in cholesterol determinations was stated for milk (1".81 %) and the least for cream (11.02%)

The content of cholesterol in butter depending on the season and production method

The seasonal variations in the cholesterol content in butter in relation to the fatty acid compositions were studied. No statistically significant differences in the cholesterol content depending on the season of the year were found. The differences in the cholesterol content in butter manufactured conventionally or continuously were also insignificant (p=0.05). The analysis of correlation showed statistically significant (p=0.05) dependence between the butter cholesterol content and iodine value (r=0.47), volatile fatty acids content (r=-0.38), and the C16:0/C18:0 ratio (r = 0.36).Przebadano sezonowe zmiany zawartości cholesterolu w maśle i ich związek ze zmianami składu tłuszczu mlekowego. Nie wykazano statystycznie istotnego zróżnicowania zawartości cholesterolu zależnie od okresu produkcji masła (tab. 1, 2). Nie wykazano też statystycznie istotnych różnic zawartości cholesterolu w maśle produkowanym metodą periodyczną i ciągłą (tab. 3). Przeprowadzona analiza korelacji (tab. 4, rys. 1, 2 i 3) wykazała statystycznie istotną zależność między zawartością cholesterolu w tłuszczu mlekowym a wartością liczby jodowej (r = 0,47), zawartością grupy lotnych kwasów tłuszczowych (r = -0,38) oraz ilorazem zawartości kwasów C16:0/C18:0 (r = 0,36)

Zaleznosc miedzy skladem kwasow tluszczowych a stopniem redukcji poziomu cholesterolu podczas frakcjonowanej krystalizacji tluszczu mlekowego

Correlation coefficient (r) and regression analysis were employed to determine the relationship between the cholesterol content and iodine value (IV), the C40/C36 and C54/C52 triacylglycerols (TAG) and unsaturated/saturated fatty acids (UFA/SFA) ratios in anhydrous milk fat (AMF) and its fractions after dry crystallization at 30°C and 20°C. Over a period of one year, the content of cholesterol in milk fat from ten dairies in North-East Poland varied depending on the season of the year within the range of 1.80 g/kg to 2.12 g/kg. Upon dry crystallization of AMF, cholesterol was concentrated in the UFA-rich liquid fractions in which its contents after dry crystallization at 30°C and 20°C increased on average by 3% and 7%, respectively, whereas in respective crystal fractions decreased by 18% and 22% as compared to the AMF content. At least a 2-fold increase in TBA index proved that intensive oxidations occurred during the fractionation, at 20°C particularly. The cholesterol content dependence of IV, the C40/C36 and UFA/SFA ratios was found to be statistically significant (r 0.85, 0.69 and 0.75, respectively), while C54/C52 ratio statistically insignificant (r 0.53) at α=0.05. A linear regression equation was determined for the relationship between IV and cholesterol content. Power, exponential and hyperbolic equations described the relationship between the cholesterol content and the ratios of C40/C36, C54/C52 and UFA/SFA, respectively.Współczynnikami korelacji i równaniami regresji określono zależność między liczbą jodową, stosunkiem triacylogliceroli (TAG) C40 i C36 oraz C54 i C52, i kwasów nienasyconych do nasyconych a zawartością cholesterolu w bezwodnym tłuszczu mlekowym (AMF) i jego frakcjach po frakcjonowanej krystalizacji w temp. 30 i 20°C. W okresie jednego roku, wykazano sezonowe zróżnicowanie zawartości cholesterolu (1,80-2,12 g/kg, tab. 1) w AMF, pozyskanym z próbek masła produkowanego w 10 zakładach Polski północno-wschodniej. W procesie frakcjonowanej krystalizacji AMF cholesterol akumulował się we frakcji płynnej o wysokiej zawartości nienasyconych kwasów tłuszczowych (tab. 1, rys. 1, 2, 3). Zawartość cholesterolu we frakcjach płynnych po krystalizacji AMF w temp. 30 i 20°C zwiększyła się średnio o 3% i 7%, a we frakcjach stałych zmniejszyła się o 18% i 22% w porównaniu z zawartością w AMF. Statystycznie istotną zależność (p=0,05) stwierdzono między zawartością cholesterolu a liczbą jodową, stosunkiem TAG C40 i C36 oraz kwasów nienasyconych i nasyconych (współczynniki korelacji odpowiednio: 0,85; 0,69 i 0,75, tab. 2). Statystycznie nieistotna była zależność między zawartością cholesterolu a stosunkiem TAG C54 i C52 (r 0,53). Równania regresji (tab. 2) opisujące zależność między zawartością cholesterolu a liczbą jodową, stosunkiem TAG C40 i C36 oraz C54 i C52, i kwasów nienasyconych do nasyconych miały charakter odpowiednio liniowy, potęgowy, wykładniczy i hiperboliczny

Reduction of cholesterol in butter depending on cream acidity

The differences in the butter content of cholesterol depending on the butter plasma acidity and type of lactic acid bacteria used for cream ripening were examined. Statistically significant effect of the plasma acidity on the content of cholesterol in butter was shown. Lower content of cholesterol was found in the butters with the higher plasma acidity. The butter content of cholesterol was also found to decrease when the Lactobacillus acidophilus strains, unusual in butter production, were employed for cream ripening.Przebadano zróżnicowanie zawartości cholesterolu w maśle w zależności od stopnia ukwaszenia plazmy oraz rodzaju stosowanych szczepionek bakterii fermentacji mlekowej w procesie dojrzewania biologicznego śmietanki (tab. 1). Badania wykazały istotny statystycznie wpływ stopnia ukwaszenia plazmy masła na zawartość w nim cholesterolu. Niższą zawartość cholesterolu stwierdzono w próbkach o wyższej kwasowości plazmy (tab. 2, 3, 4; rys. 1, 2). Wykazano także redukcję zawartości cholesterolu w maśle w wyniku zastosowania nietypowych przy tego typu produkcji szczepów Lactobacillus acidophilus

Iontophoresis-Assisted Corneal Collagen Cross-Linking with Epithelial Debridement: Preliminary Results

Purpose. To report the early outcomes of iontophoresis-assisted corneal collagen cross-linking procedure with epithelial debridement (I-SCXL). Methods. Twenty eyes of twenty patients with progressive keratoconus were included in this prospective clinical study. Best spectacle corrected visual acuity (BSCVA), sphere and cylinder refraction, corneal topography, Scheimpflug tomography, aberrometry, anterior segment optical coherence tomography (AS-OCT), and endothelial cell count were assessed at baseline and at 1, 3, and 6 months of follow-up. The parameters considered to establish keratoconus progression were always proven with differential maps as change in curvature in the cone area of at least 1 diopter obtained with an instantaneous map. Results. Functional parameters showed a significant improvement (p 0.05). Conclusion. The early results indicate that the I-SCXL may be able to reduce the treatment time and improve the riboflavin diffusion