Effects of block shape and inclination on the stability of melange bimrocks

A wide range of heterogeneous geological units composed of strong rock blocks enclosed in a bonded matrix of fine texture exists worldwide. Such geomaterials belong to geotechnically complex formations and are often referred to as bimrocks (block-in-matrix rocks) or bimsoils (block-in-matrix soils), as a function of their matrix characteristics and the interface strength between the matrix and blocks. Stability problems occurring in such complex geomaterials have been analysed almost exclusively by means of deterministic approaches and with the aim of investigating the effects of variable block contents on their mechanical behaviour. However, bimrocks and bimsoils can present very different internal block-in-matrix arrangements and properties according to their forming process and, consequently, significantly dissimilar mechanical behaviours. Therefore, the aim of this paper was to statistically investigate and compare the stability of theoretical slopes in the most widespread bimrock formations, i.e. sedimentary and tectonic melanges. These formations are characterised by substantial differences in their rock inclusion geometry. To this aim, a great number of 2D slope models were generated to enclose blocks with variable shapes, dimensions, arrangements, inclinations and contents. To obtain statistically based results, fifteen configurations were analysed for each block content and geometrical configuration considered. The results obtained indicate that block shapes and orientations significantly affect the stability of slopes in bimrocks only when the block contents are greater than 40%. Moreover, it is demonstrated that blocks inclined 0° to the horizontal provide the most tortuous and irregular failure surfaces and, consequently, the highest safety factors.

Egg Case Protein 3: A Constituent of Black Widow Spider Tubuliform Silk

Spider silk has outstanding mechanical properties, rivaling some of the best materials on the planet. Biochemical analyses of tubuliform silk have led to the identification of TuSp1, egg case protein 1, and egg case protein 2. TuSp1 belongs to the spidroin superfamily, containing a non-repetitive N- and C-terminal domain and internal block repeats. ECP1 and ECP2, which lack internal block repeats and sequence similarities to the highly conserved N- and C-terminal domains of spidroins, have cysteine-rich N-terminal domains. In this study, we performed an in-depth proteomic analysis of tubuliform glands, spinning dope, and egg sacs, which led to the identification of a novel molecular constituent of black widow tubuliform silk, referred to as egg case protein 3 or ECP3. Analysis of the translated ECP3 cDNA predicts a low molecular weight protein of 11.8 kDa. Real-time reverse transcription–quantitative PCR analysis performed with different silk-producing glands revealed ECP3 mRNA is predominantly expressed within tubuliform glands of spiders. Taken together, these findings reveal a novel protein that is secreted into black widow spider tubuliform silk.

Improved Meet-in-the-Middle Attacks on Reduced-Round Deoxys-BC-256

In ASIACRYPT 2014, Jean et al. proposed the authentication encryption scheme Deoxys, which is one of the third-round candidates in CAESAR competition. Its internal block cipher is called Deoxys-BC that adopts the tweakey frame. Deoxys-BC has two versions of the tweakey size that are 256 bits and 384 bits, denoted by Deoxys-BC-256 and Deoxys-BC-384, respectively. In this paper, we revaluate the security of Deoxys-BC-256 against the meet-in-the-middle attack to obtain some new results. First, we append one round at the top and two rounds at the bottom of a 6-round distinguisher to form a 9-round truncated differential path with the probability of $2^{-144}$. Based on it, the adversary can attack 9-round Deoxys-BC-256 with $2^{108}$ chosen plaintext-tweaks, $2^{113.6}$ encryptions and $2^{102}$ blocks. Second, we construct a new 6.5-round distinguisher to form 10-round attacking path with the probability of $2^{-152}$. On the basis of it, the adversary could attack 10-round Deoxys-BC-256 with $2^{115}$ chosen plaintext-tweaks, $2^{171}$ encryptions and $2^{152}$ blocks. These two attacks improve the previous cryptanalytic results on reduced-round Deoxys-BC-256 against the meet-in-the-middle attack.

Interaction of Cyclooxygenase-2 with Helicobacter pylori Induces Gastric Chronic Nonresolving Inflammation and the Formation of Syndrome of Internal Block of Static Blood in Helicobacter pylori-Related Gastric Diseases

Cyclooxygenase-2 (COX-2) is an inducible enzyme stimulated by various inflammatory factors (IFs). Chronic gastritis is a classic model of “inflammation-cancer transformation” and Helicobacter pylori-related gastric diseases (HPGD) are specific ones of this model. Traditional Chinese Medicine (TCM) syndromes could play a predictive role in gastric histopathological evolution. To search for early warning evidence about “inflammation-cancer transformation,” this study is about to explore interaction of COX-2 with Helicobacter pylori (Hp) in HPGD with different TCM syndromes. All included subjects underwent endoscopy and biopsy. Hp infection was detected by rapid urease test and methylene blue staining. Histopathological characteristics and COX-2 expression in gastric mucosa (GM) were, respectively, observed by hematoxylin-eosin and Elivision™ plus. SPSS 18.0 and Stata 11.0 statistical software packages were used for statistical analysis. Results of immunohistochemical staining in this study showed COX-2 expression in Hp-positive patients was stronger than that in Hp-negative ones. Spearman’ analysis indicated that degrees of both Hp infection and COX-2 expression were positively correlated with those of gastric inflammation and inflammatory activity. Compared with the relative normal group, both severe dysplasia group and gastric carcinoma group had more severe Hp infection and COX-2 expression. Compared with the nonsyndrome, syndrome of internal block of static blood (IBSB) had higher scores in semiquantitative analysis of COX-2 protein expression among TCM groups. Moreover, multivariate logistics regression analysis suggested that patients with Hp infection could increase the risk of IBSB. These results indicated that COX-2 interacting with Hp could play an important role in transforming gastric chronic nonresolving inflammation into carcinoma in subjects with HPGD, as well as inducing the formation of IBSB. HPGD together with IBSB could be an early warning evidence for GM with histopathological evolution from benign to malignant.

Thermal Convection of Nanoliquid in a Double-Connected Chamber

Thermogravitational convective thermal transmission, inside a square differentially-heated chamber with a nanoliquid, has been examined in the presence of internal adiabatic or a thermally-conducting solid body. A single-phase nanoliquid approach is employed, based on the experimentally-extracted relations for nanofluid heat conductivity and dynamic viscosity. The governing equations have been written using non-primitive parameters such as stream function and vorticity. Such approach allows a decrease in computational time due to a reduction of equation numbers. One of the main challenges in such a technique is a determining the stream function magnitude at the inner body walls. A solution of this problem has been described in detail in this paper. Computational scrutinizing has been performed by employing the finite difference technique. The mesh sensitivity analysis and comparison with theoretical and experimental results of other researchers have been included. An influence of the Rayleigh number, nanoparticles concentration, internal block size, heat conductivity ratio and non-dimensional time on nanofluid motion and energy transport has been studied.

DYNAMICS AND MULTIDIMENSION OF LANDSCAPE AND TECHNICAL SYSTEMS

The article analyzes the problem of dynamics and multidimensionality of landscapes on the example of landscape and technical systems. The object of the study is a landscape and technical systems, which are characterized by significant dynamics and multidimensionality of the structure. The basis for the publication of the article was the materials of long-term field observations conducted in the framework of research of the Vinnytsia school of anthropogenic landscape science under the direction of H. I. Denysyk. The authors’ contribution is to analyze the dynamics and multidimensionality of the structure and development of the valley-river landscape and technical systems of the Right Bank Ukraine, which lasted during 2007-2019. Knowledge of the dynamics of landscape and technical systems allows one to better understand the specifics of the transformation of the modern landscape sphere and to calculate possible negative trends. It is noted that the dynamics of landscape and technical systems are functional, spatial, and structural transformations, which are manifested in all components to the critical moment of transformation of a block system into a geocomponent one. Four types of dynamics are considered. Chronological dynamics characterize the spatial changes in the boundaries of the landscape and technical system. Structural dynamics involves a change in the morphological structure of the landscape and technical system and the relationships between its blocks. Temporal dynamics unites all changes in the landscape and technical system related to time. Directed dynamics presupposes stable, unilaterally directed transformations of the landscape and technical system with multiple changes of its state and structure. It is noted that each system has its own distinctive feature – multidimensionality, that is, the functioning within it of a number of separate and simultaneously interconnected paradynamic systems. The internal block system is limited by the landscape technosphere of the planet, which combines modern soils, man-made cover, and the air layer. The internal structural-morphological system considers the landscape and the technical system as a clearly defined gradation of taxa. The internal inter-block system provides interconnection in the landscape and technical system at the level of three blocks (managerial, natural and technical). The external complex system expresses the interaction of the landscape and technical system with other landscape complexes. Through the external air system, there is an entry into the landscape and technical system and the reverse radiation of solar radiation and interaction with remote landscape complexes due to the transfer of different types of air masses. In the underlying lithogenic system, the interaction of the landscape and technical system with the lithogenic base, which is represented by the earth’s crust and the upper mantle, is manifested. It is determined that the knowledge of the problems of dynamics and multidimensionality of landscape and technical systems becomes the central problem of engineering landscape science. The development of theoretical aspects of the functioning of landscape and technical systems is of great practical importance. Understanding the specifics of the structure and development of a particular landscape-technical system will increase its economic efficiency and minimize the negative impact on adjacent landscapes. Therefore, in the future, it is necessary to emphasize the research of modern geographers on the problems of multidimensionality and dynamics of different classes of anthropogenic landscapes.

Comments on “heat transfer in a square porous cavity in presence of square solid block”

Purpose The purpose of this paper is to discuss the need to attend correctly to the accuracy and the manner in which the value of the streamfunction is determined when two or more impermeable boundaries are present. This is discussed within the context of the paper by Nandalur et al. (2019), which concerns the effect of a centrally located conducting square block on convection in a square sidewall-heated porous cavity. Detailed solutions are also presented which allow the streamfunction to take the natural value on the surface of the internal block. Design/methodology/approach Steady solutions are obtained using finite difference methods. Three different ways in which insulating boundary conditions are implemented are compared. Detailed attention is paid to the iterative convergence of the numerical scheme and to its overall accuracy. Error testing and Richardson’s extrapolation have been used to obtain very precise values of the Nusselt number. Findings The assumption that the streamfunction takes a zero value on the boundaries of both the cavity and the embedded block is shown to be incorrect. Application of the continuity-of-pressure requirement shows that the block and the outer boundary take different constant values. Research limitations/implications The Darcy–Rayleigh number is restricted to values at or below 200; larger values require a finer grid. Originality/value This paper serves as a warning that one cannot assume that the streamfunction will always take a zero value on all impermeable surfaces when two or more are present. A systematic approach to accuracy is described and recommended.