scholarly journals INNOVATIVE THREAD METHOD THROUGH CYLINDRICAL HOLES

2021 ◽  
pp. 90-96
Author(s):  
Anatoliy Ostrovsky Anatoliy Ostrovsky
Keyword(s):  
Small Diameter ◽  
Threaded Connection ◽  
Cutting Surface ◽  
Modern Engineering ◽  
Wide Range ◽  
Threaded Joints ◽  
Screw Surface ◽  
Cylindrical Holes ◽  
Conjugate Surfaces ◽  
Technical Solutions

Innovative activity in the field of engineering and technology, based on the use of best practices, contributes to scientific and technological progress in production. The latest projects in the field of technology significantly increase the technical and economic performance of enterprises. Innovative technical solutions of production nature significantly improve the structure and quality of production. Given the level of the proposed technological changes in the manufacture of threads in through holes, these innovations cover the field of combinatorial and partial. Today mechanical engineering is characterized by mechanization and automation of technological processes, a wide range of products of various parts. Among the non-detachable and detachable joints of parts, the threaded connection is the most common. Simplicity, reliability, the ability to adjust the force with which the conjugate surfaces come into contact, the possibility of repeated cycles of disassembly and assembly, etc., make this type of connection the most commonly used in mechanisms and machines of modern engineering. With the simplicity of the contact pair of threaded joints, where one of them contains the outer and the other the inner screw surface, during their manufacture there are problems that significantly inhibit production. The subject of research of this article is the solution of difficulties of manufacturing of an internal cut in through openings of small diameter by means of a tap. According to various sources, up to 80% of marriage is due to breaking taps. Studies by a group of scientists has found that more than 75% of taps break when the reverse (reverse) stroke of the tap, when the torque reaches its maximum value. The reverse scheme of production of a screw profile of a cutting surface by means of the mechanized devices and their alternative analogs, and also machines of drilling group, is offered.

scholarly journals Design of 3D Additively Manufactured Hybrid Structures for Cranioplasty

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 181
Author(s):  
Roberto De Santis ◽  
Teresa Russo ◽  
Julietta V. Rau ◽  
Ida Papallo ◽  
Massimo Martorelli ◽  
...  
Keyword(s):  
Physical Models ◽  
Cranial Bone ◽  
Head Model ◽  
Rigid Sphere ◽  
Element Analysis ◽  
Aliphatic Polyesters ◽  
Hybrid Device ◽  
Wide Range ◽  
Hybrid Devices ◽  
Technical Solutions

A wide range of materials has been considered to repair cranial defects. In the field of cranioplasty, poly(methyl methacrylate) (PMMA)-based bone cements and modifications through the inclusion of copper doped tricalcium phosphate (Cu-TCP) particles have been already investigated. On the other hand, aliphatic polyesters such as poly(ε-caprolactone) (PCL) and polylactic acid (PLA) have been frequently investigated to make scaffolds for cranial bone regeneration. Accordingly, the aim of the current research was to design and fabricate customized hybrid devices for the repair of large cranial defects integrating the reverse engineering approach with additive manufacturing, The hybrid device consisted of a 3D additive manufactured polyester porous structures infiltrated with PMMA/Cu-TCP (97.5/2.5 w/w) bone cement. Temperature profiles were first evaluated for 3D hybrid devices (PCL/PMMA, PLA/PMMA, PCL/PMMA/Cu-TCP and PLA/PMMA/Cu-TCP). Peak temperatures recorded for hybrid PCL/PMMA and PCL/PMMA/Cu-TCP were significantly lower than those found for the PLA-based ones. Virtual and physical models of customized devices for large cranial defect were developed to assess the feasibility of the proposed technical solutions. A theoretical analysis was preliminarily performed on the entire head model trying to simulate severe impact conditions for people with the customized hybrid device (PCL/PMMA/Cu-TCP) (i.e., a rigid sphere impacting the implant region of the head). Results from finite element analysis (FEA) provided information on the different components of the model.

Cassava Processing in Sub-Saharan Africa: the Implications for Expanding Cassava Production

1994 ◽  
Vol 23 (3) ◽  
pp. 197-205 ◽  
Author(s):  
Felix Izu Nweke
Keyword(s):  
Food Security ◽  
Water Supply ◽  
Sub Saharan Africa ◽  
Wide Range ◽  
Intensive Use ◽  
Cassava Production ◽  
Sub Saharan ◽  
Processing Techniques ◽  
Technical Solutions ◽  
Poor Soil

Cassava makes an important contribution to improving food security and rural incomes in sub-Saharan Africa, as it is tolerant of drought and poor soil and its cultivation does not require much labour. However, the fresh roots are bulky and perishable and need to be processed before they can be marketed; processing also removes the cyanogens which make many varieties poisonous in their raw form. Cassava roots are turned into granules, flours, pastes and chips, with a wide range of flavours and appearances for different areas and markets. Many different processing techniques are used, some of which make intensive use of fuelwood while others require a plentiful water supply. These requirements, as well as the need for a good transport and marketing infrastructure, limit the expansion of cassava production in sub-Saharan Africa, but technical solutions are being found.

scholarly journals Development trends of outboard launchers for unmanned underwater vehicles and marine underwater weapons from underwater carriers (based on materials from open publications)

2020 ◽  
Author(s):  
В.О. Боярчик ◽  
В.Г. Михлин ◽  
А.А. Румянцев ◽  
Р.А. Урусов
Keyword(s):  
Rapid Development ◽  
Underwater Vehicles ◽  
Technical Condition ◽  
Mineral Deposits ◽  
Development Trends ◽  
Unmanned Underwater Vehicles ◽  
Mining Sites ◽  
Special Place ◽  
Wide Range ◽  
Technical Solutions

Принимая во внимание бурное развитие морской подводной техники для разведки и добычи полезных ископаемых со дна Мирового океана, которое невозможны без широкого использования необитаемых подводных аппаратов (НПА), вопросы, связанные с их отделением от носителя, становятся, несомненно, актуальными. Среди широкой номенклатуры подводных аппаратов, используемых для этих целей, особое место занимают НПА торпедообразной формы. К основной их миссии относят вопросы разведки мест залегания полезных ископаемых, освещения подводной обстановки при проведении работ, а также вопросы контроля технического состояния оборудования, оснащения мест добычи ископаемых, а также охраны района. В статье анализируются тенденции развития забортных пусковых установок, на основе открытых зарубежных и отечественных публикаций (статей, патентов, рекламных буклетов). Рассмотрены известные технические решения забортных пусковых установок и намечены наиболее перспективные направления развития пусковых установок. Taking into account the rapid development of marine underwater equipment for exploration and mining from the bottom of the oceans, which is impossible without the widespread use of unmanned underwater vehicles (UUV), issues related to their separation from the carrier are undoubtedly relevant. Among the wide range of underwater vehicles used for these purposes, a special place is occupied by torpedo-shaped UUV. Their main mission includes issues of exploration of mineral deposits, an overview of the underwater situation during work, as well as issues of monitoring the technical condition of equipment, equipping mining sites, as well as protecting the area. The article analyzes the development trends of overboard launchers based on open foreign and domestic publications (articles, patents, advertising booklets). The well-known technical solutions of overboard launchers are considered and the most promising directions for the development of launchers are outlined.

Capsaicin attenuates bombesin-induced suppression of food intake

1991 ◽  
Vol 260 (2) ◽  
pp. R263-R266 ◽  
Author(s):  
E. E. Ladenheim ◽  
R. C. Ritter
Keyword(s):  
Food Intake ◽  
Sensory Neurons ◽  
Intraperitoneal Administration ◽  
Small Diameter ◽  
Neural Substrates ◽  
Wide Range

This study was conducted to evaluate the extent to which bombesin (BBS)-induced suppression of food intake relies on small, unmyelinated sensory neurons. Rats were pretreated intraperitoneally with capsaicin, a neurotoxin that destroys a subpopulation of small-diameter sensory neurons, and tested for suppression of food intake after intraperitoneal administration of 2, 4, 8, 16, and 32 micrograms/kg BBS. Capsaicin pretreatment attenuated suppression of food intake by BBS over a wide range of doses. The site of capsaicin action was not determined in this study. However, work by others indicates that vagal and nonvagal neural substrates participate in suppression of food intake by BBS. Afferents of both of these substrates are predominantly small and unmyelinated. Therefore, the deficits in BBS-induced suppression of food intake that we observed may reflect damage to both vagal and/or nonvagal neurons that participate in BBS-induced suppression of food intake.

scholarly journals Endoscopic Optical Imaging Technologies and Devices for Medical Purposes: State of the Art

2020 ◽  
Vol 10 (19) ◽  
pp. 6865 ◽  
Author(s):  
Mandeep Kaur ◽  
Pierre M. Lane ◽  
Carlo Menon
Keyword(s):  
Growth And Development ◽  
State Of The Art ◽  
Precancerous Lesion ◽  
Small Diameter ◽  
Optical Components ◽  
Micro Electro Mechanical Systems ◽  
Optical Scanners ◽  
Additional Risk ◽  
Wide Range ◽  
The Subject

The growth and development of optical components and, in particular, the miniaturization of micro-electro-mechanical systems (MEMSs), has motivated and enabled researchers to design smaller and smaller endoscopes. The overarching goal of this work has been to image smaller previously inaccessible luminal organs in real time, at high resolution, in a minimally invasive manner that does not compromise the comfort of the subject, nor introduce additional risk. Thus, an initial diagnosis can be made, or a small precancerous lesion may be detected, in a small-diameter luminal organ that would not have otherwise been possible. Continuous advancement in the field has enabled a wide range of optical scanners. Different scanning techniques, working principles, and the applications of endoscopic scanners are summarized in this review.

CFD Simulation of PWR Subchannel Void Distribution Benchmark

2010 ◽  
Author(s):  
Wang-Kee In ◽  
Chang-Hwan Shin ◽  
Tae-Hyun Chun
Keyword(s):  
Void Fraction ◽  
Cfd Simulation ◽  
Fluid Model ◽  
Small Diameter ◽  
Operating Conditions ◽  
Heated Wall ◽  
Bubble Generation ◽  
Void Distribution ◽  
Wide Range ◽  
Two Fluid Model

A CFD study was performed to simulate the steady-state void distribution benchmark based on the NUPEC PWR Subchannel and Bundle Tests (PSBT). The void distribution benchmark provides measured void fraction data over a wide range of geometrical and operating conditions in a single subchannel and fuel bundle. This CFD study simulated the boiling flow in a single subchannel. A CFD code was used to predict the void distribution inside the single subchannel. The multiphase flow model used in this CFD analysis was a two-fluid model in which liquid (water) and vapor (steam) were considered as continuous and dispersed fluids, respectively. A wall boiling model was also employed to simulate bubble generation on a heated wall surface. The CFD prediction with a small diameter of vapor bubble shows a higher void fraction near the heated wall and a migration of void in the subchannel gap region. A measured CT image of void distribution indicated a locally higher void fraction near the heated wall for the test conditions of a subchannel averaged void fraction of less than about 20%. The CFD simulation predicted a subchannel averaged void fraction and fluid density which agree well with the measured ones for a low void condition.

Thermal and Cold Spray: Recent Developments

2008 ◽  
Vol 384 ◽  
pp. 1-59 ◽  
Author(s):  
Pierre Fauchais ◽  
Ghislain Montavon
Keyword(s):  
Thermal Spray ◽  
High Reliability ◽  
Small Diameter ◽  
Thermal Spraying ◽  
Melting Behavior ◽  
Decomposition Temperature ◽  
The Past ◽  
Wide Range ◽  
Powder Particles ◽  
Average Size

Thermal spraying consists in a technology aiming at producing coatings whose thicknesses range from 10 μm to a few millimeters onto mechanical components to confer them specific and unique functional properties, such as wear and corrosion resistances, friction coefficient adaptation, thermal and electrical insulation, biocompatibility, repair, etc., among the principals. Thermal spraying consists in injecting in a viscous enthalpic jet (animated by a momentum) powder with particles which average size ranges from 0.01 to 100 μm. These particles are melted and simultaneously accelerated towards the surface of the part to be covered. They form, after impact, spreading and solidification, near-circular lamellae the stacking of which form the coating. Due to the versatility of the available processes exhibiting a wide range of enthalpic and momentum contents, virtually any kind of material exhibiting congruent melting behavior can be processed, from alloys and ceramics to polymers, ever since its melting temperature differs from its vaporization or decomposition temperature by at least 300 K and that it can be processed previously under the form of powder particles or wires. Thermal spray techniques offer the unique capability to manufacture a large variety of coatings on components of a large variety and geometry. However, thermal spraying constitutes a special process for which the coating service properties derive mostly from the structure and indirectly from the selection of the operating parameters. Very significant improvements over the past years permitted to diagnose the in-flight particle characteristics, mostly in terms of velocity and temperature. Recently, these new capabilities have made possible the development of on-line process controls. This should participate to a drastic increase in coating reliability. In convetntional thermal spraying processes, a pulverulent feedstock (i.e., powder particles) is injected within the plasma jet via a carrier gas. This approach does not permit to process small diameter particles; i.e., nano-sized particles, which could permit to form finely grained coatings. Replacing gas by liquid to carry particles offer the unique possibility to process nano-sized particles. Cold gas spraying may appear as an alternative process to reach the same goal. Indeed, thermal spray processes experienced very significant developments over the past years, opening new doors to manufacture coatings with a high reliability and superior properties. This papepr indend at presenting some of those developments.

scholarly journals Fully Developed Flow of a Nanofluid through a Circular Micropipe in the Presence of Electroosmotic Effects

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Muhammad D. K. Niazi ◽  
Hang Xu
Keyword(s):  
Double Layer ◽  
Electrical Double Layer ◽  
Microelectromechanical Systems ◽  
Flow Behavior ◽  
Fluid Viscosity ◽  
Buongiorno’S Model ◽  
Flow Models ◽  
Similarity Transformations ◽  
Modern Engineering ◽  
Wide Range

Microscale heat sinks based on channels or pipes are designed to restrict the temperatures of microelectromechanical systems, which have a wide range of applications in the modern engineering and mechanics. In this context, this work aims to study heat convection and entropy generation of a fully developed nanofluid flow in a circular micropipe in the presence of an electrical double layer. Buongiorno’s model is employed to exhibit the nanofluid behavior. The governing equations are reduced to a system of nonlinear ordinary differential equations through appropriate similarity transformations. Particularly, we rectify the pressure term as an unknown constant, which makes our flow model compatible with those well-known fluid flow models in macrosize. Highly accurate solutions are obtained and verified. Analysis for physical properties of electric field, velocity field, temperature, and nanoparticle distributions is discussed followed by an investigation of the entropy evolution in the flow. The results show that flow behavior and total entropy of the system depend on the electroosmosis, thermophoresis, and fluid viscosity. However, the influence of the electrical double layer on the flow and system entropy is negligible when the electroosmotic parameter exceeds a maximum value.

Reduced Boring Bar Vibrations Using Damped Composite Structures

1995 ◽  
Author(s):  
Angela Trego ◽  
Paul F. Eastman ◽  
William F. Pratt ◽  
C. G. Jensen
Keyword(s):  
Composite Structures ◽  
New Technology ◽  
Thin Plates ◽  
Complex Structures ◽  
Design Problems ◽  
Boring Bar ◽  
Cutting Surface ◽  
Wide Range ◽  
High Frequency Vibrations ◽  
Bar Diameter

Abstract A new technology, called Stress Coupling Activated Damping (SCAD©), was applied successfully to a lathe boring bar. It reduced high frequency vibrations by up to 20 db. It can be applied to a wide range of structural designs. The geometries of the damped structures are not limited to thin plates but can be applied to tubes, I-beams, and complex structures. This allows SCAD© technology to be applied to several industry design problems, including the metrology, medical, aerospace, automotive and machine tool industries. SCAD© will also allow boring bars to: 1) be optimized for stiffness, frequency and loss factor, 2) be ‘tuned’ to a specific resonant frequency, 3) have improved damping regardless of boring bar diameter, 4) lengthen the usable tool length without a significant increase in cost, and 5) decrease cutting surface vibration induced pattern.

A note on robotics and artificial intelligence in pharmacy

2021 ◽  
Vol 08 ◽  
Author(s):  
Sankha Bhattacharya
Keyword(s):  
Artificial Intelligence ◽  
Development Process ◽  
Pharmaceutical Companies ◽  
Drug Products ◽  
Drug Molecules ◽  
Wide Range ◽  
Organ Tissue ◽  
Technical Solutions ◽  
And Robotics

: Artificial intelligence and robotics are two of the hottest and most recent technologies to emerge from the world of science. There is tremendous potential for these technologies to solve a wide range of pharmaceutical problems, including the reduction of the enormous amounts of money and time invested in the drug discovery and development process, technical solutions related to the quality of drug products, and an increase in the demand for pharmaceuticals. Nanorobotics is a new subfield that has emerged from the field of robotics itself. This technique makes use of robots that are as small as nano- or micron-sized to diagnose diseases and deliver drugs to the targeted organ, tissue, or cell. These techniques, as well as their various applications in the pharmacy sector, are extensively discussed throughout this article. Internationally renowned pharmaceutical companies are collaborating with Artificial Intelligence behemoths in order to revolutionise the discovery and development process of potential drug molecules and to ensure the highest possible quality in their products.

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