Probabilistic design of ground improvement by vertical drains for soil of spatially variable coefficient of consolidation

The design of soil consolidation via prefabricated vertical drains (PVDs) has been traditionally carried out deterministically and thus can be misleading due to the ignorance of the uncertainty associated with the inherent variability of soil properties. To treat such uncertainty in the course of design of soil improvement by PVDs, more rational probabilistic methods are necessary. In this paper, a simplified probabilistic method is proposed in which the inherent variability of the coefficient of consolidation, which is the most significant uncertain soil parameter that affects the consolidation process, is considered. An easy-to-use design procedure and charts are provided for routine use by practitioners.     

Validation of a Method for Analysis of Aroma Compounds in Red Wine using Liquid–Liquid Extraction and GC–MS

An analytical method for determination of volatile composition of wines using sample preparation by liquid–liquid extraction and gas chromatography coupled to mass spectrometry for separation and detection has been developed and validated. Extraction of volatile compounds was performed in dichloromethane, and 1-octanol was added as an internal standard. Kékfrankos red wine produced in Villány wine region in Hungary was used as a model wine for testing and validation of the method. The developed method allowed satisfactory determination of 33 volatile compounds in the wines. Compounds analyzed include alcohols, esters, lactones, fatty acids, furans, and nitrogen compounds. The calibration curves of the four reference compounds used (2-phenyl ethanol, ethyl nonanoate, butyrolactone, and tyrosol) were linear in all cases with correlation coefficients (R ²) ranging from 0.9951 to 0.9992. The accuracy of the method was checked with a standard addition method (recovery 92.2–103 %), showing good repeatability and reproducibility (RSD?<?10 %).     

Biohybrid Bovine Bone Matrix for Controlled Release of Mesenchymal Stem/Stromal Cell Lyosecretome: A Device for Bone Regeneration

SmartBone^® (SB) is a biohybrid bone substitute advantageously proposed as a class III medical device for bone regeneration in reconstructive surgeries (oral, maxillofacial, orthopedic, and oncology). In the present study, a new strategy to improve SB osteoinductivity was developed. SB scaffolds were loaded with lyosecretome, a freeze-dried formulation of mesenchymal stem cell (MSC)-secretome, containing proteins and extracellular vesicles (EVs). Lyosecretome-loaded SB scaffolds (SBlyo) were prepared using an absorption method. A burst release of proteins and EVs (38% and 50% after 30 min, respectively) was observed, and then proteins were released more slowly with respect to EVs, most likely because they more strongly adsorbed onto the SB surface. In vitro tests were conducted using adipose tissue-derived stromal vascular fraction (SVF) plated on SB or SBlyo. After 14 days, significant cell proliferation improvement was observed on SBlyo with respect to SB, where cells filled the cavities between the native trabeculae. On SB, on the other hand, the process was still present, but tissue formation was less organized at 60 days. On both scaffolds, cells differentiated into osteoblasts and were able to mineralize after 60 days. Nonetheless, SBlyo showed a higher expression of osteoblast markers and a higher quantity of newly formed trabeculae than SB alone. The quantification analysis of the newly formed mineralized tissue and the immunohistochemical studies demonstrated that SBlyo induces bone formation more effectively. This osteoinductive effect is likely due to the osteogenic factors present in the lyosecretome, such as fibronectin, alpha-2-macroglobulin, apolipoprotein A, and TGF-β.     

Effect of Oxide Fluxes on Depth of Penetration in Flux Bounded Tungsten Inert Gas Welding of AISI 304L Stainless Steel

Flux Bounded Tungsten Inert Gas (FBTIG) welding is a modified TIG welding process in which increased depth of penetration (DoP) can be achieved by laying thin flux coatings on either side of the weld centerline. The effect of three single component fluxes viz., SiO₂, TiO₂ and Cr₂O₃ on bead geometry of autogenous melt runs in AISI 304L stainless steel for the gap between the flux layers varying from 2 to 7 mm, is studied. Results show that DoP can be improved significantly in FBTIG process using single component fluxes. Nature of the flux and the gap between the flux layers influence the weld bead geometry. Among the three fluxes used, SiO₂ is more efficient in improving the DoP. Arc constriction is the predominant mechanism operative in improving the DoP in FBTIG welding. Possibility of change in solidification mode in FBTIG weld metals of stainless steels is highlighted.     

Mass-velocity correlation in impact induced fragmentation of heterogeneous solids

We study the impact fragmentation of disordered solids by means of a discrete element model focusing on the velocity and mass-velocity correlation of fragments. Simulations are performed with plate-like objects varying the plate thickness and the impact velocity in broad ranges. Depending on the impact velocity the breakup process has two different outcomes: at low velocities the sample gets only damaged, to achieve fragmentation, where no large residues survive, the impact velocity has to surpass a critical value. In the fragmented phase the velocity components of fragments are power law distributed with a stretched exponential cutoff, where the impact velocity and plate thickness mainly control the standard deviation of the distributions. Mass velocity correlation is only pointed out for thin plates, while it disappears for three-dimensional bulk samples. In the damage phase of thin plates the mass and velocity of fragments proved to be strongly correlated, however, in the fragmented phase correlation occurs in the vicinity of the critical velocity and it is limited to the large fragments only. The correlation function decays as a power law with different exponents for small and large fragments in good agreement with recent experimental findings. We show that the mass-velocity correlation originates from the spatial dependence of the mass and velocity of pieces inside the fragmenting body.     

The Un(f)told Story of General Anesthesia

Inhalational anesthetics are routinely employed in clinical practice to accomplish general anesthesia. Concerns have recently emerged regarding the deleterious impact of these volatile agents on cognitive performance, immune functions, and tumor recurrence and metastasis. These agents have been shown to modify the gene‐expression pattern as well as cell signaling in tumor cells, but the underlying molecular mechanisms remain a matter of conjecture. Regulatory/signaling proteins either of cytosolic or membrane origin abundantly contain intrinsically disordered sequences, the conformational pliability of which is pivotal in their biological functions. It is well known that chloroform (an anesthetic itself), trifluoroethanol, hexafluoroisopropanol, and related haloalcohols markedly affect the structure of disordered proteins and protein regions by inducing folding, misfolding, or even aggregation. Taking into consideration the physicochemical similarities and protein interaction modes of these volatile solvents and inhaled anesthetics, it is postulated that administration of these drugs can also modify the secondary structure of disordered protein segments. Accordingly, pharmacological effects of anesthetics may, at least in part, be mediated by conformational perturbations of intrinsic disorder‐based regulatory protein networks of cells.     

Influence of the coupling agent and graphene oxide on the thermal and mechanical behavior of tea dust–polypropylene composites

In this study, the effects of a coupling agent and additive on the physicomechanical (morphological, mechanical, thermal, and swelling) properties of tea dust (TD)–polypropylene (PP) composites were studied. TD–PP composites were prepared with untreated tea dust (UTD) and tetraethylsilane (TES)‐treated TD or silanated tea dust (STD) particles at ratios of 0:100, 10:90, 20:80, 30:70, and 40:60 w/w. Initially, TD particles were grafted by TES as a coupling agent, and these STD particles were then modified with graphene oxide (GO) as an additive to study their effects on the STD–PP composites; these were compared to the STD–PP and UTD–PP composites in accordance with a study of improvements in the mechanical properties. All of the TD–PP composites were analyzed with Fourier transform infrared spectroscopy, scanning electron microscopy, and mechanical, thermal, and physical tests. The thermal and mechanical properties of both the STD–PP and GO‐modified STD–PP composites were found to be improved as compared to those of the UTD–PP composites. So, the recycling of a large amount of TD as a waste material could be useful in the preparation of TD–PP composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42927.     

Ultra-trace Analysis of Enantiomeric Impurities in Proteinogenic N-Fmoc-Amino-acid Samples on Cinchona Alkaloid-based Chiral Stationary Phases

The enantiomeric purity of N_α-Fmoc-protected amino acids is crucial from the viewpoint of peptide synthesis; therefore, a sensitive high-performance liquid chromatographic protocol was developed for the identification and quantification of enantiomeric impurities of commercially available N_α-Fmoc-protected amino acids on Cinchona alkaloid quinine- and quinidine-based weak anion exchanger-type chiral stationary phases. In the course of the evaluation of the chiral chromatographic method, the effect of the mobile phase composition, nature, and concentration of different additives were optimized. The specific phenomenon that quinine- and quinidine-based chiral stationary phases behave as pseudo-enantiomers permits that the sequence of elution of the enantiomers might be reversed by simple column switching. This is quite advantageous as regards the separation of the minor component in the presence of the major one. The method developed permits detection of less than 0.01 % enantiomeric impurity in the presence of the major enantiomer.