FORMATION OF CRUSHING ZONE AT THE LEVEL OF TAMPING IN THE CONDITIONS OF MASS EXPLOSIONS

The purpose of the work is to study the sequence of formation of the fracture zone in the area of the array above the ends of the system of adjacent charges in connection with the technological parameters of their mutual location. The task of works is the analytically substantiate the dependence of the value of the undamaged area of the array at the level of the bottomhole on the parameters of the system of downhole charges, taking into account the phenomenon of the edge effect. Research results. Data on the dimentions of the part of the massif in the lborewhole that does not participate in the mass deformation motion of the rock during the formation of adjacent downhole funnels are obtained. It is assumed that this area between adjacent charges is the source of the oversized fraction. Originality. The process of formation of the destroyed zone in space above the end of the boreholeis considered step by step: generation of the shock wave front, the symmetry of which is close to spherical, formation of the loosenning funnel system in the second stage, which does not adjacent charges of the total front of the stress wave from the explosion of downhole charges detonated from their bottom. Behind him moves the deformation front of a complex structure. It is assumed that this front in the system of two adjacent charges acquires a shape similar to a vertical wedge inverted by the base towards the free surface. The expected result of such a step-by-step deformation process is the desired degree of crushing of the rock mass at the level of the tamping. Conclusions and practical implications. Theoretically and calculatedly obtained and recommended rational parameters of the location of the system of well charges of limited length to reduce the size of the non-destructive region of the rock mass at the level of the tamping, which improves the design of mass explosions in mountain slopes.

A Review on IEEE-754 Standard Floating Point Multiplier using Vedic Mathematics

The fundamental and the core of all the Digital Signal Processors (DSPs) are its multipliers and the speed of the DSPs is mainly determined by the speed of its multiplier. IEEE floating point format is a standard format used in all processing elements since Binary floating point numbers multiplication is one of the basic functions used in digital signal processing (DSP) application. In this work VHDL implementation of Floating Point Multiplier using Vedic mathematics is carried out. The Urdhva Tiryakbhyam sutra (method) was selected for implementation since it is applicable to all cases of multiplication. Multiplication of two no’s using Urdhva Tiryakbhyam sutra is performed by vertically and crosswise. The feature is any multi-bit multiplication can be reduced down to single bit multiplication and addition using this method. On account of these formulas, the carry propagation from LSB to MSB is reduces due to one step generation of partial product.

One-Step Generation of Multiple Gene-Edited Pigs by Electroporation of the CRISPR/Cas9 System into Zygotes to Reduce Xenoantigen Biosynthesis

Xenoantigens cause hyperacute rejection and limit the success of interspecific xenografts. Therefore, genes involved in xenoantigen biosynthesis, such as GGTA1, CMAH, and B4GALNT2, are key targets to improve the outcomes of xenotransplantation. In this study, we introduced a CRISPR/Cas9 system simultaneously targeting GGTA1, CMAH, and B4GALNT2 into in vitro-fertilized zygotes using electroporation for the one-step generation of multiple gene-edited pigs without xenoantigens. First, we optimized the combination of guide RNAs (gRNAs) targeting GGTA1 and CMAH with respect to gene editing efficiency in zygotes, and transferred electroporated embryos with the optimized gRNAs and Cas9 into recipient gilts. Next, we optimized the Cas9 protein concentration with respect to the gene editing efficiency when GGTA1, CMAH, and B4GALNT2 were targeted simultaneously, and generated gene-edited pigs using the optimized conditions. We achieved the one-step generation of GGTA1/CMAH double-edited pigs and GGTA1/CMAH/B4GALNT2 triple-edited pigs. Immunohistological analyses demonstrated the downregulation of xenoantigens; however, these multiple gene-edited pigs were genetic mosaics that failed to knock out some xenoantigens. Although mosaicism should be resolved, the electroporation technique could become a primary method for the one-step generation of multiple gene modifications in pigs aimed at improving pig-to-human xenotransplantation.

Home-made enzymatic premix and Illumina sequencing allow for one-step Gibson assembly and verification of virus infectious clones

An unprecedented number of viruses have been discovered by leveraging advances in high-throughput sequencing. Infectious clone technology is a universal approach that facilitates the study of biology and role in disease of viruses. In recent years homology-based cloning methods such as Gibson assembly have been used to generate virus infectious clones. We detail herein the preparation of home-made cloning materials for Gibson assembly. The home-made materials were used in one-step generation of the infectious cDNA clone of a plant RNA virus into a T-DNA binary vector. The clone was verified by a single Illumina reaction and a de novo read assembly approach that required no primer walking, custom primers or reference sequences. Clone infectivity was finally confirmed by Agrobacterium-mediated delivery to host plants. We anticipate that the convenient home-made materials, one-step cloning and Illumina verification strategies described herein will accelerate characterization of viruses and their role in disease development.