scholarly journals Compact silencers with discrete baffle elements for new-generation light small arms

2021 ◽  
Vol 2021 (4) ◽  
pp. 18-28
Author(s):  
O.V. Pylypenko ◽  
◽  
N.A. Konovalov ◽  
V.I. Kovalenko ◽  
D.V. Semenchuk ◽  
...  
Keyword(s):  
Gas Flow ◽  
High Efficiency ◽  
Operational Reliability ◽  
Discrete Elements ◽  
Expansion Chamber ◽  
Small Arms ◽  
Technical Requirements ◽  
Space Agency ◽  
External Part ◽  
New Generation

This paper presents the results of the development of silencers, whose design features discrete baffle elements. The advisability of silencers of this type is confirmed by their operational reliability and shot sound suppression efficiency in their actual service as part of light small arms of different types. To design advanced silencers, technical requirements for their design were developed. The paper describes the possibility of using discrete elements (cones, hemispheres, flat baffles, etc.) as the key component of a powder gas spreader. Differently shaped elements are used as additional elements that form a powder gas flow inside a silencer: for example, cylindrical elements, including perforated ones to provide a powder gas flow between the expansion chambers. One way to increase silencer efficiency is an additional expansion chamber that embraces the external part of the barrel and is gas-dynamically connected to a traditional muzzle silencer. In deciding on an optimum design for compact silencers, the following was redetermined: the number of expansion chambers and the dimensions thereof, the powder gas energy converter design, the baffle type, the presence of a gas flow between the chambers near the inner surface of the silencer body, and, if so, the gas flow rate. The silencer design was optimized based on simulating the processes inside the silencer using the authors’ efficiency calculation procedure for silencers with different internal components. Comparison tests of the silencers developed and foreign silencers confirmed a high efficiency of the former. The silencers with discrete baffles for light small arms developed at the Institute of Technical Mechanics of the National Academy of Ukraine and the State Space Agency of Ukraine compare well in performance with their best foreign counterparts. The designs of some of them are covered by Ukrainian patents.

Compact silencers for new-generation light small arms

2021 ◽  
Vol 2021 (2) ◽  
pp. 20-35
Author(s):  
O.V. Pylypenko ◽  
◽  
N.A. Konovalov ◽  
V.I. Kovalenko ◽  
◽  
...  
Keyword(s):  
Gas Flow ◽  
High Efficiency ◽  
Design Feature ◽  
Operational Reliability ◽  
National Academy Of Sciences ◽  
Expansion Chamber ◽  
Small Arms ◽  
Technical Requirements ◽  
Space Agency ◽  
Perforated Tube

This paper presents the results of the development of silencers, whose design feature is a central perforated tube, at the institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine (ITM of NASU and SSAU). The advisability of silencers of this type is confirmed by their operational reliability and shot sound suppression efficiency in their actual service as part of light small arms of different types. To design high-efficiency advanced silencers, technical requirements for their design were developed. The paper describes the possibility of using a central perforated tube as the key component of a powder gas spreader. Differently shaped elements or a combination thereof are used as additional elements that form a powder gas flow inside a silencer: conical and spherical axisymmetric baffles coaxial with the silencer body, cylindrical shells (including perforated ones) that provide a powder gas flow between the expansion chambers along the internal axis of the central channel, helicoidal elements, and peripheral labyrinth-vortex contours. One way to increase silencer efficiency is an additional expansion chamber that embraces the external part of the barrel and is gas-dynamically connected to a traditional muzzle silencer. In deciding on an advisable design for compact silencers, the following was redetermined: the number of expansion chambers, the powder gas energy converter design, the baffle type, the presence of a gas flow between the chambers along the inner surface of the silencer body, and, if so, the gas flow rate. The silencer design was optimized based on simulating the silencer gas dynamics using the authors’ efficiency calculation procedure for silencers with a central perforated tube and different internal components. The paper describes the procedure and presents the results calculated with its help. Comparison tests of the silencers developed and foreign silencers confirmed a high efficiency of the former. The silencers with a central perforated tube for light small arms developed at the ITM of NASU and SSAU compare well in performance with their best foreign counterparts. The designs of some of them are covered by Ukrainian patents.

Materials for bullet core

2020 ◽  
Vol 2020 (10) ◽  
pp. 8-21
Author(s):  
A. G. Kolmakov ◽  
◽  
I. O. Bannykh ◽  
V. I. Antipov ◽  
L. V. Vinogradov ◽  
...  
Keyword(s):  
High Speed ◽  
Bending Strength ◽  
Low Alloy Steels ◽  
Hard Alloys ◽  
Small Arms ◽  
Alloy Steels ◽  
Materials Used ◽  
Basic Ideas ◽  
New Generation ◽  
Natural Composite

he basic ideas about the process of introducing cores into protective barriers and the most common core patterns and their location in conventional and sub-caliber small arms bullets are discussed. The materials used for manufacture of cores are analyzed. It is concluded that for mass bullets of increased armor penetration the most rational choice can be considered the use of high-carbon low-alloy steels of a new generation with a natural composite structure and hardness of up to 70 HRC. For specialized armor-piercing bullets, cores made from promising economically-alloyed high-speed steels characterized by a high complex of «hardness—bending strength» are better alternative than ones made of hard alloys or tungsten alloys.

scholarly journals Recent Advancements in Polythiophene-Based Materials and Their Biomedical, Geno Sensor and DNA Detection

2021 ◽  
Vol 22 (13) ◽  
pp. 6850
Author(s):  
Seyyed Mojtaba Mousavi ◽  
Seyyed Alireza Hashemi ◽  
Sonia Bahrani ◽  
Khadije Yousefi ◽  
Gity Behbudi ◽  
...  
Keyword(s):  
Biomedical Engineering ◽  
High Efficiency ◽  
Polymeric Materials ◽  
The Novel ◽  
Electrode Coating ◽  
Effective Response ◽  
Hiv Drugs ◽  
New Generation ◽  
New Compounds ◽  
Anti Hiv

In this review, the unique properties of intrinsically conducting polymer (ICP) in biomedical engineering fields are summarized. Polythiophene and its valuable derivatives are known as potent materials that can broadly be applied in biosensors, DNA, and gene delivery applications. Moreover, this material plays a basic role in curing and promoting anti-HIV drugs. Some of the thiophene’s derivatives were chosen for different experiments and investigations to study their behavior and effects while binding with different materials and establishing new compounds. Many methods were considered for electrode coating and the conversion of thiophene to different monomers to improve their functions and to use them for a new generation of novel medical usages. It is believed that polythiophenes and their derivatives can be used in the future as a substitute for many old-fashioned ways of creating chemical biosensors polymeric materials and also drugs with lower side effects yet having a more effective response. It can be noted that syncing biochemistry with biomedical engineering will lead to a new generation of science, especially one that involves high-efficiency polymers. Therefore, since polythiophene can be customized with many derivatives, some of the novel combinations are covered in this review.

scholarly journals The Bacterial Enzyme Cas13 Interferes with Neurite Outgrowth from Cultured Cortical Neurons

Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 262
Author(s):  
Qin-Wei Wu ◽  
Josef P. Kapfhammer
Keyword(s):  
Rna Editing ◽  
Cortical Neurons ◽  
High Efficiency ◽  
Primary Cultures ◽  
Cultured Neurons ◽  
Therapeutic Tool ◽  
Bacterial Enzyme ◽  
Rna Targeting ◽  
Cultured Cortical Neurons ◽  
New Generation

The CRISPR-Cas13 system based on a bacterial enzyme has been explored as a powerful new method for RNA manipulation. Due to the high efficiency and specificity of RNA editing/interference achieved by this system, it is currently being developed as a new therapeutic tool for the treatment of neurological and other diseases. However, the safety of this new generation of RNA therapies is still unclear. In this study, we constructed a vector expressing CRISPR-Cas13 under a constitutive neuron-specific promoter. CRISPR-Cas13 from Leptotrichia wadei was expressed in primary cultures of mouse cortical neurons. We found that the presence of CRISPR-Cas13 impedes the development of cultured neurons. These results show a neurotoxic action of Cas13 and call for more studies to test for and possibly mitigate the toxic effects of Cas13 enzymes in order to improve CRISPR-Cas13-based tools for RNA targeting.

Effect Of Equivalent Ratio (ER) On the Flow and Combustion Characteristics in A Typical Underground Coal Gasification (UCG) Cavity

2021 ◽  
Vol 86 (2) ◽  
pp. 28-38
Author(s):  
Arup Kumar Biswas ◽  
Wasu Suksuwan ◽  
Khamphe Phoungthong ◽  
Makatar Wae-hayee
Keyword(s):  
Mass Flow ◽  
Flow Rate ◽  
Gas Flow ◽  
Coal Gasification ◽  
High Efficiency ◽  
Combustion Characteristics ◽  
Raw Material ◽  
Underground Coal Gasification ◽  
Equivalent Ratio ◽  
Rubble Pile

Underground Coal Gasification (UCG) is thought to be the most favourable clean coal technology option from geological-engineering-environmental viewpoint (less polluting and high efficiency) for extracting energy from coal without digging it out or burning it on the surface. UCG process requires only injecting oxidizing agent (O2 or air with steam) as raw material, into the buried coal seam, at an effective ratio which regulates the performance of gasification. This study aims to evaluate the influence of equivalent ratio (ER) on the flow and combustion characteristics in a typical half tear-drop shape of UCG cavity which is generally formed during the UCG process. A flow modeling software, Ansys FLUENT is used to construct a 3-D model and to solve problems in the cavity. The boundary conditions are- (i) a mass-flow-inlet passing oxidizer (in this case, air) into the cavity, (ii) a fuel-inlet where the coal volatiles are originated and (iii) a pressure-outlet for flowing the product Syngas out of the cavity. A steady-state simulation has been run using k-? turbulence model. The mass flow rate of air varied according to an equivalent ratio (ER) of 0.16, 0.33, 0.49 and 0.82, while the fuel flow rate was fixed. The optimal condition of ER has been identified through observing flow and combustion characteristics, which looked apparently stable at ER 0.33. In general, the flow circulation mainly takes place around the ash-rubble pile. A high temperature zone is found at the air-releasing point of the injection pipe into the ash-rubble pile. This study could practically be useful to identify one of the vital controlling factors of gasification performance (i.e., ER impact on product gas flow characteristics) which might become a cost-effective solution in advance of commencement of any physical operation.

Increasing of Energy-Power Indicators of Mechanical Processing in a Planetary Mill by the Use of a Working Chamber with a Square Shape of the Internal Cavity

2020 ◽  
Vol 299 ◽  
pp. 447-451 ◽  
Author(s):  
V.G. Gusev ◽  
A.V. Sobolkov ◽  
A.V. Aborkin
Keyword(s):  
High Efficiency ◽  
Computational Study ◽  
High Energy ◽  
Planetary Mill ◽  
Internal Cavity ◽  
Cylindrical Shape ◽  
Mechanical Processing ◽  
Discrete Elements ◽  
Working Chamber ◽  
Processing Regimes

The paper presents the results of a computational study of the influence of the geometry of the working chamber on the energy-force interaction of grinding bodies in the process of the mixture processing in a planetary mill. The method of computer simulation, using the software system, based on the ideology of discrete elements, shows the high efficiency of processing in a planetary mill, using a working chamber with a square-shaped cavity. The values of the factors that have a dominant influence on the mechanical processing of the charge are determined. A comparison with the process of processing in the working chamber of the traditional cylindrical shape is made. The research results will be used in the appointment of large-size charge processing regimes that provide a high-energy grinding process.

scholarly journals Challenges and Approaches to Scaling the Global Commons

2021 ◽  
Vol 4 ◽  
Author(s):  
Felix Fritsch ◽  
Jeff Emmett ◽  
Emaline Friedman ◽  
Rok Kranjc ◽  
Sarah Manski ◽  
...  
Keyword(s):  
Large Scale ◽  
Sharing Economy ◽  
Natural Habitats ◽  
Common Value ◽  
Exchange Value ◽  
Space Agency ◽  
The Commons ◽  
Common Goals ◽  
Distribution Of Power ◽  
New Generation

The re-emergence of commoning over the last decades is not incidental, but rather indicative of a large-scale transition to a more “generative” organization of society that is oriented toward the planet’s global carrying capacity. Digital commons governance frameworks are of particular importance for a new global paradigm of cooperation, one that can scale the organization of communities around common goals and resources to unprecedented levels of size, complexity and granularity. Distributed Ledger Technologies (DLTs) such as blockchain have lately given new impetus to the emergence of a new generation of authentic “sharing economy,” protected from capture by thorough distribution of power over infrastructure, that spans not only digital but also physical production of common value. The exploration of the frontiers of DLT-based commoning at the heart of this article considers three exemplary cases for this new generation of commons-oriented community frameworks: the Commons Stack, Holochain and the Commons Engine, and the Economic Space Agency. While these projects differ in their scope as well as in their relation to physical common-pool resources (CPRs), they all share the task of redefining markets so as to be more conducive to the production and sustainment of common value(s). After introducing each of them with regards to their specificities and commonalities, we analyze their capacity to foster commons-oriented economies and “money for the commons” that limit speculation, emphasize use-value over exchange-value, favor equity in human relations, and promote responsibility for the preservation of natural habitats. Our findings highlight the strengths of DLTs for a federated scaling of CPR governance frameworks that accommodates rather than obliterates cultural differences and creates webs of fractal belonging among nested communities.

Industrial Sewing Machine Design and Development of Digital Design and Simulation Platform

2013 ◽  
Vol 365-366 ◽  
pp. 917-920
Author(s):  
De Fa Zhang ◽  
Yi Cong Gao
Keyword(s):  
Energy Saving ◽  
High Performance ◽  
High Efficiency ◽  
Machine Intelligence ◽  
Digital Design ◽  
Machine Design ◽  
Design And Development ◽  
Sewing Machine ◽  
Great Leap Forward ◽  
New Generation

In recent years, industrial sewing machine intelligence can be increased. Compared with the traditional equipment, the new generation of domestic equipment in the "high efficiency, energy saving, special" has realized great-leap-forward development. In the performance, will towards high precision, high efficiency, high performance, intelligent direction; in function, to the miniaturization, multi-function direction; in the program, to the systematic, integrated direction. The design and development of industrial sewing machine digitization design packaging platform are discussed.

scholarly journals Efficiency Evaluation of the Ejector Cooling Cycle using a New Generation of HFO/HCFO Refrigerant as a R134a Replacement

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2136 ◽  
Author(s):  
Bartosz Gil ◽  
Jacek Kasperski
Keyword(s):  
High Efficiency ◽  
Coefficient Of Performance ◽  
Condensation Temperature ◽  
Evaporation And Condensation ◽  
Wide Range ◽  
Theoretical Investigations ◽  
Maximum Coefficient ◽  
C 30 ◽  
New Generation ◽  
And Control

Theoretical investigations of the ejector refrigeration system using hydrofluoroolefins (HFOs) and hydrochlorofluoroolefin (HCFO) refrigerants are presented and discussed. A comparative study for eight olefins and R134a as the reference fluid was made on the basis of a one-dimensional model. To facilitate and extend the possibility of comparing our results, three different levels of evaporation and condensation temperature were adopted. The generator temperature for each refrigerant was changed in the range from 60 °C to the critical temperature for a given substance. The performed analysis shown that hydrofluoroolefins obtain a high efficiency of the ejector system at low primary vapor temperatures. For the three analyzed sets of evaporation and condensation temperatures (te and tc equal to 0 °C/25 °C, 6 °C/30 °C, and 9 °C/40 °C) the maximum Coefficient of Performance (COP) was 0.35, 0.365, and 0.22, respectively. The best performance was received for HFO-1243zf and HFO-1234ze(E). However, they do not allow operation in a wide range of generator temperatures, and, therefore, it is necessary to correctly select and control the operating parameters of the ejector.

scholarly journals MEs in Nano-Medicine

2012 ◽  
Vol 134 (06) ◽  
pp. 36-41
Author(s):  
Guy M. Genin ◽  
Ram V. Devireddy
Keyword(s):  
Tissue Engineering ◽  
Regenerative Medicine ◽  
Osteogenesis Imperfecta ◽  
High Efficiency ◽  
Medical Diagnostics ◽  
Imperial College ◽  
Current Generation ◽  
The Core ◽  
Nano Medicine ◽  
New Generation

This article reviews the use of mechanical engineering techniques in the field of nano-engineered medicines. Nano-engineered solutions now exist for a range of medical diagnostics, therapeutics, and imaging, and are at the core of many of the current generation of regenerative medicine and tissue engineering strategies. Nanoparticles can be developed to absorb energy with high efficiency from photons of certain frequency ranges. The ability to understand specific diseases such as osteogenesis imperfecta based upon such fundamental analyses has been demonstrated by ASME member Sandra Shefelbine of Imperial College London in collaboration with the Buehler group. The tools of nanotechnology have enabled mechanical engineers to engineer the beginnings of an entirely new generation of cures and therapies, and this article has discussed just a sample. In order to serve as a forum for discussion of these advances ASME is recommissioning the Journal of Nanotechnology in Engineering and Medicine.

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