Comparative analysis of roller drill bit performance

Currently, roller bits are widely used in rock drilling, which are devices with rotating rollers armed with teeth. There are various approaches in assessing the effectiveness of rock destruction by a roller drilling tool, which can be conditionally divided into structural and technological ones. In addition, all the efficiency factors of the roller bit are related to the correspondence of its characteristics and the drilling process to the properties of the rock it destroys. The article analyzes the operating conditions of the roller bit during drilling of rocks of various hardness. On the example of operation of a two-screw drill bit, the process of power interaction of the toothed weapon with rock is considered depending on various factors, such as the shape and pitch of the teeth, angle of inclination, sharpness of the tooth and others. It is shown that kinematic characteristics of interaction of toothed armament with drilled rock have a significant influence on efficiency of process of face destruction. Keywords: drill bit; drilling tool; destruction; drilling; roller cutter; rock.

role and importance of the digital economy in the development of innovative

The research reveals that theoretical foundations, stages, driving forces, efficiency factors of modern digitalization are considered as digital economy. The key components of the term “digital economy” are presented: digital technologies, ecosystems and transformations, taking into account their interconnection and interdependence, as well as continuity with the previously developed conceptual series - informatization, intellectualization and robotization. Also, the article presents a clear understanding of the object and subject of research, the importance of the essence of the digital economy phenomenon and the stages of its development. The purpose of this study is to study the relationship between digital technologies, innovative and economic development, describe the advantages and disadvantages of digitalization for countries with different levels of economic development. It is noted that the digital economy is an integral part of the information (digital) environment, forming in accordance with the needs of the real sector of the economy and the needs of society, changing under the influence of technological innovations.

ECONOMIC ANALYSIS OF YAM PROCESSING INTO YAM FLOUR IN SAKI AGRO ECOLOGICAL ZONE OF OYO STATE, NIGERIA

The study examined the economic analysis of yam processing into yam flour in Saki Agro ecological Zone of Oyo State. It specifically described the profitability of yam processing; examined the technical efficiency of yam processors and determined the effect of the socio-economic characteristics on technical efficiency. Data were collected with the aid of structured questionnaire and analyzed using descriptive statistics, profitability and budgetary analysis as well as stochastic frontier model and Garrett scale. The study reveals that majority of the respondents were female (88%) with a mean age of 47. The result shows that the rate of return on investment was 12 percent. The mean technical efficiency of the processors was 85% indicating that the yam processors were relatively efficient in allocating their limited resources. Some observable variables relating to socioeconomic characteristics such as processing experience and sex of the respondents significantly explains the variation in technical efficiency. Factors such as high cost of yam tubers, poor weather condition and inadequate processing facilities are the major factors that hinder the processing activities in the study area. The study therefore recommends that government policies should be made to improve the provision of inputs such as yam tubers and capital equipment at affordable price.

Cluster Analysis of Existing Technoparks in Developed Countries

This article provides a cluster analysis of existing technoparks, the sample of which was built according to the completeness of the data presented on the official websites of the Ministry of Industry and Trade of the Russian Federation and the terms of operation. The analysis is carried out in order to determine the best components of the effectiveness of the development of the technopark movement in Russia. According to the analysis of this article, we can talk about a weak relationship between the three sub-indices: the activities of the management company, the activities of residents, the activities of regional authorities. The obtained data can serve as a starting base for further construction of an econometric model of the efficiency factors of technoparks.

Algorithms for Delivery of Data by Drones in an Isolated Area Divided into Squares

Drones are frequently used for the delivery of materials or other goods, and to facilitate the capture and transmission of data. Moreover, drone networks have gained significant interest in a number of scenarios, such as in quarantined or isolated areas, following technical damage due to a disaster, or in non-urbanized areas without communication infrastructure. In this context, we propose a network of drones that are able to fly on a map covered by regular polygons, with a well-established mobility schedule, to carry and transfer data. Two means exist to equidistantly cover an area with points, namely, grouping the points into equilateral triangles or squares. In this study, a network of drones that fly in an aerial area divided into squares was proposed and investigated. This network was compared with the case in which the area is divided into equilateral triangles. The cost of the square drone network was lower than that of the triangular network with the same cell length, but the efficiency factors were better for the latter. Two situations related to increasing the drone autonomy using drone charging or battery changing stations were analyzed. This study proposed a Delay Tolerant Network (DTN) to optimize the transmission of data. Multiple simulation studies based on experimental flight tests were performed using the proposed algorithm versus five traditional DTN methods. A light Wi-Fi Arduino development board was used for the data transfer between drones and stations using delivery protocols. The efficiency of data transmission using single-copy and multiple-copy algorithms was analyzed. Simulation results showed a better performance of the proposed Time-Dependent Drone (TD-Drone) Dijkstra algorithm compared with the Epidemic, Spray and Wait, PRoPHET, MaxProp, and MaxDelivery routing protocols.

Key Factors for Implementing Magnetic NDT Method on Thin UHPFRC Bridge Elements

This paper provides an overview of the use of the magnetic NDT method for estimating the fibre content, and fibre orientation and efficiency factors in thin UHPFRC elements/layers, along any two orthogonal directions. These parameters are of utmost importance for predicting the post-cracking tensile strength in the directions of interest. After establishing meaningful correlations at the lab-specimen scale, this NDT method can be effectively implemented into quality control protocols at the industrial production scale. The current study critically addresses the influence of key factors associated with using this NDT method in practice and provides recommendations for its efficient implementation.

Precooling of table grapes on a commercial scale as function of packaging

ABSTRACT Although precooling by forced air is widely used to remove field heat from fresh table grapes, there is no knowledge about its use and efficiency. Factors influencing the process include temperature and relative air humidity, amount and initial temperature of the fruits, air velocity, and packaging. The objective of this study was to evaluate the cooling effect and efficiency of forced air cooling on table grapes in two types of packages. The experimental method used randomized blocks, in a 2 × 3 factorials, corresponding to two package types (polystyrene and cardboard) and three heights on the pallet - lower, middle, and upper - with four replicates. The temperature gradient in the direction of the airflow was evaluated. There was heterogeneity in cooling, both vertically and horizontally, on the pallets with a central heat zone for both the directions. None of the packages was suitable for fast cooling as both types of packages showed a cooling time of 15.5 h; moreover, relative humidity values were far below the ideal value for table grapes.

Analysis of the efficiency factors of electrotransformation of Bacillus subtilis to inactivate the aroK gene by the method of homologous recombination

A hyper-osmotic electrotransformation method was developed for strain Bacillus subtilis. Sorbitol and mannitol are included in the hyper-osmotic electroporation medium and recovery medium. In this study, the hyper-osmotic electroporation method was optimised to increase the transformation efficiency of B. subtilis strain 5434 (non-transformable by chemical methods) by 430 fold, with a maximum value of 8.6 ⋅ 105 CFU/µg of integrative plasmid DNA. With the electroporation setted 25 µF, 23 kV/cm, 200 Ω, the method was optimised as follows: a) the OD600 value of the bacterial culture solution was increased to about 1.2, which significantly enhanced survival of bacteria and quantity of viable B.subtilis strain 5434 cells after electroporation; b) the elution frequency of washing solution (hyper-osmotic electroporation medium) for complement cells was increased from 3 to 5 times, resulted in significantly reducing the conductivity of the hyper-osmotic electoporation medium with competent cells (electrocompetent cultue), and effectively extending the pulse time under the same electric field strength; c) quantity of integrative plasmid DNA added to hyper-osmotic electrocompetent culture was optimised. These results indicate that increasing the number of viable B. subtilis strain 5434 cells and reducing the number of metal ions in the electroporation solution mix (integrative plasmid DNA, competent cells of B. subtilis strain 5434, electroporation medium) are useful approach to improve transfomation efficiency of B. subtilis strain 5434. Concentration of shikimic acid in the fermentation medium was quantified by high performance liquid chromatography. Quantification of shikimic acid revealed that B. subtilis strain 5434p4SA produced 403.98 ± 9.1 µg/mL of shikimic acid.

Urban Infrastructure Resilience Assessment During Mega Sport Events Using a Multi-Criteria Approach

Critical infrastructures share the same space and mutual dependencies, and consequently contribute to city's overall resilience. However, each has different assessment methods and metrics, which prevents the integration of the performance results for different infrastructures into a single holistic evaluation index that can reflect the city's overall resilience and expected performance. To address this challenge, we propose the development of a multi-criteria-based integration approach that can allow the combination of different evaluation results from different assessment methods through partial factors. The proposed equation incorporates several factors, which can be divided into four groups: (1) method-efficiency factors, (2) infrastructure importance factors, (3) infrastructures' interdependency factors, and (4) strict limits that ensure that the infrastructures are suitable for hosting mega sports events. Using this approach, we hope to open the way for future research into suitable factors and facilitate resilience-based design in sustainable development and municipal planning.