Removal of Microbial Biofilms from Dispense Equipment: The Effect of Enzymatic Pre‐digestion and Detergent Treatment

Microbial biofilms can form in dispense outlets as a result of poor or inadequate cleaning and can be difficult to remove using conventional practices. Enzymatic cleaners might help to remove biofilms by degrading the exopolysaccharide layers in which the microbes are embedded. A multispecies biofilm comprising wild type dispense isolates of Flavimonas oryzihabitans, Lactobacillus brevis, Leuconostoc mesenteroides and Saccharomyces cerevisiae was generated on a section of tubing and fitted into a pilot dispense system, which was left uncleaned for 12 weeks. After cleaning approximately 10⁴ viable aerobes and 10³ viable anaerobes were still present. Stainless steel coupons and pieces of dispense line contaminated with biofilm were incubated in the laboratory with an enzyme mix containing varying proportions of α‐amylase, β‐glucuronidase, glucose oxidase, dextranase, protease and pectinase. Cultures grown on stainless steel had significantly (F pr. > 0.05) less viable cells than non‐enzyme treated biofilms, but this was dependent on the microbial species. Typically Lactobacillus brevis was most susceptible to the enzyme treatment. Cultures grown on dispense line were much more resistant to enzymatic digestion. Pre‐digestion with protease was most effective for removal of Lactobacillus brevis and Leuconostoc mesenteroides but not for Saccharomyces cerevisiae and Flavimonas oryzihabitans. In the simulated bar, pre‐digestion with protease reduced the viable cell count by 0.64 log units for the aerobes and 1.9 log units for the anaerobes. This study demonstrates that pre‐digestion with enzyme solutions before line cleaning is useful for treating heavily contaminated lines in trade.     

Effect of way of cooking on content of essential polyunsaturated fatty acids in muscle tissue of humpback salmon (Oncorhynchus gorbuscha)

Contents of fatty acids in filets of unfrozen (control), boiled, fried, roasted and boiled in a small amount of water humpback salmon, collected from a wholesale market in Krasnoyarsk city (Siberia, Russia) were analyzed. Special attention was paid to essential polyunsaturated fatty acids of ω3 family: eicosapentaenoic, 20:5ω3 (EPA) and docosahexaenoic, 22:6ω3 (DHA). Heat treatment in general did not decrease content of EPA and DHA in humpback, except a modest reduction during frying. Cooked humpback appeared to be the valuable source of essential ω3 PUFAs, namely EPA and DHA. It was hypothesized that the absence of significant reduction of PUFAs’ contents in red flesh of fishes of Salmonidae family during heat treatment may be due to a high level of natural antioxidants which formed in the course of evolution as adaptation to their ecological niche.     

Über die Berechnung der instationären Erwärmung von supraleitenden Bauelementen

Zusammenfassung Mit Hilfe der Laplace-Transformation wird die nichtstation?re Erw?rmung berechnet, die beim Schalten von Bauelementen mit einem überzug aus supraleitendem Stoff auf einer festen Unterlage in elektronischen Rechenmaschinen entsteht. Aus einer numerischen Auswertung verschiedener Beispiele (Zinnüberzug auf Glas, Quarz und Saphir) geht hervor, da? die Schaltimpulse bei Unterlagen aus Quarz die kleinsten Temperaturschwankungen bewirken.     

A single-step isolation of squalene from olive oil deodorizer distillates by using centrifugal partition chromatography

High added-value squalene (SQ) was purified in one step from olive oil deodorizer distillates (OODD) using preparative centrifugal partition chromatography (CPC) method, operating in the dual mode. The fractionation was performed using a non-aqueous biphasic solvent system consisting of heptane–acetonitrile–butanol (1.8:1.4:0.7, v/v/v), leading to the isolation of the target compound in 4 hours, using a preparative 1L column. Furthermore, a fast UHPLC-DAD method was developed and applied for the identification and quantification of SQ in both OODD and purified form. The content of SQ in the initial material was 23.4%, while the purity of the isolated SQ was 95.5%. The recovery of SQ was calculated at 76.3%. The productivity of the process was calculated at 234 mg/h/L.     

The interplay of online shopping motivations and experiential factors on personalized e-commerce: A complexity theory approach

The present study aims to examine purchase behavior in personalized online shopping by employing complexity theory, based on customers’ online shopping experience and online shopping motivations. To address its objectives, a conceptual model is proposed along with research propositions. The research propositions are validated through a survey on 401 customers’ experience with online shopping, by using the data analysis tool fsQCA (fuzzy-set Qualitative Comparative Analysis). The results, indicate nine configurations of online shopping experience and online shopping motivations that lead to high purchase intentions. This study takes a step further the literature of online shopping and the theoretical ground of how customers’ online shopping experience combines with their online shopping motivations in order to predict and explain increased intention to purchase. The findings offer implications for both researchers and online retailers, regarding the development of new theories in personalized e-commerce and the provision of personalized services.     

Ti3SiC2-Cu composites by mechanical milling and spark plasma sintering: Possible microstructure formation scenarios

We present several possible microstructure development scenarios in Ti₃SiC₂-Cu composites during mechanical milling and Spark Plasma Sintering (SPS). We have studied the effect of in situ consolidation during milling of Ti₃SiC₂ and Cu powders and melting of the Cu matrix during the SPS on the hardness and electrical conductivity of the sintered materials. Under low-energy milling, (3–5) vol.%Ti₃SiC₂-Cu composite particles of platelet morphology formed, which could be easily SPS-ed to 92–95% relative density. Under high-energy milling, millimeter-scale (3–5) vol.%Ti₃SiC₂-Cu granules formed as a result of in situ consolidation and presented a challenge to be sintered into a bulk fully dense sample; the corresponding SPS-ed compacts demonstrated a finer-grained Cu matrix and more significant levels of hardening compared to composites of the same composition processed by low-energy milling. The 3 vol.% Ti₃SiC₂-Cu in situ consolidated and Spark Plasma Sintered granules showed an extremely high hardness of 227 HV. High electrical conductivity of the Ti₃SiC₂-Cu composites sintered from the granules was an indication of efficient sintering of the granules to each other. Partial melting of the Cu matrix, if induced during the SPS, compromised the phase stability and uniformity of the microstructure of the Ti₃SiC₂-Cu composites and thus it is not to be suggested as a pathway to enhanced densification in this system.     

Information content of data measured with a multiple-field-of-view lidar

Lidars with multiple fields of view (MFOVs) are promising tools for gaining information on cloud particle size. We perform a study of the information content of MFOV lidar data with the use of eigenvalue analysis. The approach we have developed permits an understanding of the main features of MFOV lidars and provides a way to relate the accuracy of particle size estimation with the measurement uncertainty and the scattering geometry such as the cloud-base height and the lidar sounding depth. Second-order scattering computations are performed for an extended range of particle sizes and for a wide range of lidar fields of view (FOVs). The results obtained allow us to specify the areas of possible applications of these lidars in cloud studies. Comparison of results obtained with polarized and cross-polarized scattered components demonstrate that the cross-polarized signal should provide a more stable retrieval and is preferable when double scattering is highly dominant. Our analysis allows for the estimation of the optimal number of FOVs in the system and their angular distribution, so this work can be a useful tool for practical MFOV lidar design.