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51.
The paper considers the problems of numerical discovering the shock wave parameters in porous materials. The taks is solved in continuum approximation by replacing the original heterogeneous system with a model, the properties thereof are described in similarity criteria, determining the body compressibility, the shock wave velocity scale and “strength” of the disturbing acting on the substance. Given are the basic equations to calculate π(x)-dependences. The comparison with results of the calculation and with experimental data testifies in favour of the given ideas. The composition of three-dimensional (P, θ, θ0) state surfaces illustrates the active affect of porosity on dynamic compression of the dispersed materials. The analysis of typical surface state bendings permits to choose correctly the optimal means and methods of impulse loading for obtaining the needed technological effects. 相似文献
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Sylwester Mazurek Roman Szostak Agnieszka Kita Alicja Z. Kucharska Anna Sokół-Łętowska Karel Hamouz 《Food Analytical Methods》2017,10(12):3964-3971
The application of vibrational spectroscopy for the determination of total polyphenols content, antioxidant activity, colour parameters, and fat level in chips originated from yellow-, red- and purple-fleshed potato varieties is reported. Raman, infrared (IR) and near-infrared (NIR) spectra of the laboratory-prepared chips were collected. Combining spectral data with the results of reference analyses, partial least squares regression models were built. To characterise and compare the elaborated models, the relative standard errors of prediction were calculated for calibration and validation sets. In the case of total phenolics quantification by Raman/IR/NIR techniques, these errors (%) amounted to 4.0/7.0/7.1 and 6.4/8.5/8.4 for calibration and validation samples, respectively, whereas they were 4.9/7.7/4.8 and 6.6/8.3/6.8 for antioxidant activity. The obtained results demonstrate that both infrared and Raman spectroscopy can effectively replace commonly used extraction methods. It follows that Raman spectroscopy has the highest potential to be adopted for the online potato-derived product analysis. 相似文献
54.
Ozan Nazim Ciftci Roman Przybylski Magdalena Rudzinska Surya Acharya 《Journal of the American Oil Chemists' Society》2011,88(10):1603-1610
The composition and content of lipids, fatty acids, triacylglycerols, tocopherols and sterols in nine fenugreek genotypes
were analyzed. Lipid content in fenugreek seeds ranged from 5.8 to 15.2%. Major fatty acids were: linoleic acid (45.1–47.5%),
α-linolenic (18.3–22.8%), oleic (12.4–17.0%), palmitic (9.8–11.2%) and stearic (3.8–4.2%) acids. The ratios of n-6 to n-3
fatty acids were between 2.1 and 2.7. Similar fatty acid distribution was observed in all analyzed samples with some deviations.
α-Tocopherol was the predominant component found in the fenugreek lipid antioxidants, and it constituted over 84% of the total
amounts of tocopherols. It amounts ranged from 620 to 910 mg/kg lipids. β-Sitosterol was the major sterol in all samples,
varying from 14,203 to 18,833 mg/kg of lipids. Campesterol and cycloartenol were other major sterols, and these compounds
including β-sitosterol constituted 56–72% of all sterols. Fenugreek seed lipids consisted predominantly triunsaturated (56.9–66.5%)
and diunsaturated (32.2–41.6%) triacylglycerides. Among these components trilinolein (LLL; 12.9–20.5%) dominated followed
by PLL (14.0–20.4%), LnLnO (7.8–17.7%), PLO (5.7–11.6%), OLL (6.9–10.6%), LLLn (3.2–9.6%), and LnLnL (3.5–7.6%). Results of
the study show that fenugreek seed lipids may be a source of a nutraceutical ingredient for food applications. 相似文献
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In this work we discuss the finite element model using the embedded discontinuity of the strain and displacement field, for
dealing with a problem of localized failure in heterogeneous materials by using a structured finite element mesh. On the chosen
1D model problem we develop all the pertinent details of such a finite element approximation. We demonstrate the presented
model capabilities for representing not only failure states typical of a slender structure, with crack-induced failure in
an elastic structure, but also the failure state of a massive structure, with combined diffuse (process zone) and localized
cracking. A robust operator split solution procedure is developed for the present model taking into account the subtle difference
between the types of discontinuities, where the strain discontinuity iteration is handled within global loop for computing
the nodal displacement, while the displacement discontinuity iteration is carried out within a local, element-wise computation,
carried out in parallel with the Gauss-point computations of the plastic strains and hardening variables. The robust performance
of the proposed solution procedure is illustrated by a couple of numerical examples. Concluding remarks are stated regarding
the class of problems where embedded discontinuity finite element method (ED-FEM) can be used as a favorite choice with respect
to extended FEM (X-FEM). 相似文献
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59.
Roman Cichon Krystyna Elkowicz Halina Kozlowska Antoni Rutkowski Willem C. Sauer 《Journal of the science of food and agriculture》1980,31(7):677-684
The nutritive value of protein of blends consisting of meat and soya bean protein products, which replaced either 20 or 40 % of protein of meat, were determined in rat feeding experiments. Protein efficiency ratio (PER) and net protein utilisation (NPU) were significantly lower (P<0.05) in blends containing either 20% protein from soya isolate or 40% protein from soya concentrate or soya flakes than blends containing sirloin only. However, there were no significant differences in PER and NPU when model meat (consisting of 70 and 30% protein from sirloin and connective tissue, respectively) was replaced by up to 20% protein from soya isolate or up to 40% protein from soya concentrate. 相似文献
60.
Dr. Wojciech Schönemann Dr. Jonathan Cramer Tobias Mühlethaler Dr. Brigitte Fiege Marleen Silbermann Dr. Said Rabbani Dr. Philipp Dätwyler Dr. Pascal Zihlmann Dr. Roman P. Jakob Dr. Christoph P. Sager Dr. Martin Smieško Dr. Oliver Schwardt Prof. Dr. Timm Maier Prof. Dr. Beat Ernst 《ChemMedChem》2019,14(7):749-757
Antimicrobial resistance has become a serious concern for the treatment of urinary tract infections. In this context, an anti-adhesive approach targeting FimH, a bacterial lectin enabling the attachment of E. coli to host cells, has attracted considerable interest. FimH can adopt a low/medium-affinity state in the absence and a high-affinity state in the presence of shear forces. Until recently, mostly the high-affinity state has been investigated, despite the fact that a therapeutic antagonist should bind predominantly to the low-affinity state. In this communication, we demonstrate that fluorination of biphenyl α-d -mannosides leads to compounds with perfect π–π stacking interactions with the tyrosine gate of FimH, yielding low nanomolar to sub-nanomolar KD values for the low- and high-affinity states, respectively. The face-to-face alignment of the perfluorinated biphenyl group of FimH ligands and Tyr48 was confirmed by crystal structures as well as 1H,15N-HSQC NMR analysis. Finally, fluorination improves pharmacokinetic parameters predictive for oral availability. 相似文献