scholarly journals Preparation Method of Spherical and Monocrystalline Aluminum Powder

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 375 ◽  
Author(s):  
Mateusz Skalon ◽  
Marek Hebda ◽  
Ricardo Buzolin ◽  
Gernot Pottlacher ◽  
Stefan Mitsche ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Aluminum Powder ◽  
Electron Backscatter Diffraction ◽  
High Surface ◽  
Spherical Shape ◽  
Production Method ◽  
Processing Temperature ◽  
Powder Preparation ◽  
New Production ◽  
Aluminum Particles

This paper presents a new production method for a spherical and monocrystalline aluminum powder. Aluminum powder of irregular particle shapes was mixed with silica nanoparticles and heated to a temperature above the melting point of aluminum. Due to its molten state, high surface tension, and poor wettability, the aluminum particles were transformed into liquid and spherical droplets separated by silica nanoparticles. The spherical shape was then retained when the aluminum particles solidified. The influence of the processing temperature on the particle shape, phase composition, and microstructure was investigated. Moreover, calorimetric, X-ray diffraction, grain size, and scanning electron microscopy with electron backscatter diffraction (SEM-EBSD) measurements of the particles’ microstructure are presented. It is proven that, by this means, a spherical and monocrystalline aluminum powder can be efficiently created directly from an air-atomized irregular powder. The observed phenomenon of particles becoming round is of great importance, especially when considering powder preparation for powder-based additive manufacturing processes.

Recent Advances in Application of Azobenzenes Grafted on Mesoporous Silica Nanoparticles in Controlled Drug Delivery Systems Using Light as External Stimulus

2020 ◽  
Vol 20 (11) ◽  
pp. 1001-1016
Author(s):  
Sandra Ramírez-Rave ◽  
María Josefa Bernad-Bernad ◽  
Jesús Gracia-Mora ◽  
Anatoly K. Yatsimirsky
Keyword(s):  
Drug Delivery ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Drug Delivery Systems ◽  
Mesoporous Silica Nanoparticles ◽  
High Surface ◽  
Delivery Systems ◽  
Surface Reactivity ◽  
External Stimulus ◽  
Recent Advances

Hybrid materials based on Mesoporous Silica Nanoparticles (MSN) have attracted plentiful attention due to the versatility of their chemistry, and the field of Drug Delivery Systems (DDS) is not an exception. MSN present desirable biocompatibility, high surface area values, and a well-studied surface reactivity for tailoring a vast diversity of chemical moieties. Particularly important for DDS applications is the use of external stimuli for drug release. In this context, light is an exceptional alternative due to its high degree of spatiotemporal precision and non-invasive character, and a large number of promising DDS based on photoswitchable properties of azobenzenes have been recently reported. This review covers the recent advances in design of DDS using light as an external stimulus mostly based on literature published within last years with an emphasis on usually overlooked underlying chemistry, photophysical properties, and supramolecular complexation of azobenzenes.

scholarly journals Production organization capacity of ethnic minorities in northwestern region of Vietnam

2020 ◽  
Vol 210 ◽  
pp. 16004
Author(s):  
Thu Trang Vu ◽  
Dung Vu ◽  
Thi Mai Lan Nguyen
Keyword(s):  
Ethnic Minorities ◽  
Shifting Cultivation ◽  
Production Capacity ◽  
Production Method ◽  
Small Scale ◽  
New Production ◽  
Organization Capacity ◽  
Northwestern Region ◽  
Traditional Production ◽  
Production Organization

Survey results of 1,452 people representing families of 6 ethnic minorities in 11 communes of 7 districts in 7 provinces in the Northwest region shows that the production organization capacity of the ethnic minorities surveyed has changed, but still remains many limitations. The change in production capacity of ethnic minorities is reflected in the fact that the majority of families have produced in a new way (know how to use some machines, use new plant varieties and breeds, apply chemical fertilizers, use pesticides, and some agricultural products produced for sale). The limitations of the production organization capacity of ethnic minority families are shifting cultivation, dibbling, rudimentary production tools, low labor productivity, production by small-scale, autarky, shifting cultivation of wandering hilltribes). If comparing between traditional production method and new production method, the traditional production method is still more prevalent. One of the main causes of this situation is that ethnic minorities live in mountainous areas with difficult transportation, so the main cultivation method is shifting cultivation. The application of machines in production faces many difficulties.

Specifics of Microstructure and Phase Composition of High-Speed Steel R6M5

2013 ◽  
Vol 404 ◽  
pp. 20-24 ◽  
Author(s):  
Маzhyn Skakov ◽  
Bauyrzhan Rakhadilov ◽  
Gaukhar Karipbayeva
Keyword(s):  
Phase Composition ◽  
High Speed ◽  
Volume Fraction ◽  
Electron Backscatter Diffraction ◽  
High Speed Steel ◽  
Spherical Shape ◽  
Xrd Analysis ◽  
Steel R6m5 ◽  
Solid Carbide ◽  
Backscatter Diffraction

In this paper microstructure, morphology, elemental composition, phase composition and crystal structure of the sample steel R6M5 were investigate by using the methods of scanning electron microscopy, electron backscatter diffraction (EBSD) analysis and X-ray diffraction (XRD) analysis. Determined that the microstructure of steel R6M5 after hardening and three-time tempering consists of tempered martensite and solid carbide M6C and MC-type with spherical shape and a diameter of less than 3 μm. Detected that the volume fraction of each carbide amounted to 10.4±0.6% and 2.3±0.4% - for grey and bright carbides, respectively, and that the sizes of bright carbides particles in the microstructure of steel R6M5 are 0.4-4,5 μm, and the sizes of grey carbides particles are 0.5-1.1 μm. XRD analysis showed that the main carbides in the studied steel are carbides М6С and MC, which have complicated the FCC crystal lattice and the Fd3m spatial group. Determined that carbides are uniform and monocrystalline. ESBD analysis with the support of the XRD analysis showed that carbides spherical shape М6С fit to Fe3W3C composition.

HORIZONTAL DRILLING, A NEW PRODUCTION METHOD

1988 ◽  
Vol 28 (1) ◽  
pp. 41
Author(s):  
Jacques Bosio
Keyword(s):  
World Wide ◽  
Horizontal Wells ◽  
Production Method ◽  
New Production ◽  
Horizontal Drilling ◽  
New Approach ◽  
Flow Geometry ◽  
The Future ◽  
Deviated Wells

Vertical or deviated wells cross a production formation for only short distances. Horizontal wells, however, are capable of remaining within a reservoir for distances up to several hundred metres in an effort to enhance production possibilities.A world-wide coverage of the method will be presented, with the latest information on drilling, logging, completion and costs.Application of horizontal wells will be described with an emphasis on the production results recently obtained and, more particularly, on the Rospo Mare field, offshore, in the Adriatic Sea.Horizontal wells are providing a new approach to the flow geometry within a production formation. There is no doubt that they will be used more and more in the future to optimise the drainage of most reservoirs.

scholarly journals Impact Toughness of FRTP Composites Produced by 3D Printing

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5654
Author(s):  
Milan Vaško ◽  
Milan Sága ◽  
Jaroslav Majko ◽  
Alan Vaško ◽  
Marián Handrik
Keyword(s):  
3D Printing ◽  
Mechanical Testing ◽  
Impact Load ◽  
Production Method ◽  
Research Area ◽  
New Production ◽  
Manufacturing Method ◽  
Continuous Fibre ◽  
Research Activities ◽  
The Impact

The additive manufacturing represents a new production method of composites reinforced with a continuous fibre. In recent times, the material produced by this new manufacturing method constituted a replacement for conventional materials—e.g., steel in many technical areas. As the research on FRTP composites is currently under way, the purpose of this article is to add information to the mosaic of studies in this research area. The scientific articles published until now have focused especially on mechanical testing, such as tensile and bending mechanical testing and their assessment. Therefore, the authors decided to carry out and assess the impact test of the FRTP composites produced by 3D printing because this area offers a large extent of research activities. We observed the influence of the reinforcement in the form of the micro-fibre carbon in the thermoplastic (Onyx) or a continuous reinforcement fibre in the lamina on the specimen’s behaviour during the impact load processes. The results of the experimental measurements show that the presence of a continuous fibre in the structure significantly affects the strength of the printed specimens; however, the design process of the printed object has to take into account the importance of selecting a suitable fibre type. The selection of a suitable strategy for arranging the fibre in the lamina and the direction of the impact load against the position of the fibre seem to be very important parameters.

scholarly journals Manufacture of face gearing – a new production method by means of determined material pre-distribution

2018 ◽  
Vol 15 ◽  
pp. 511-518 ◽  
Author(s):  
André Weiß ◽  
Mathias Liewald ◽  
Alexander Weiß ◽  
Nadja Missal
Keyword(s):  
Production Method ◽  
New Production

Synthesis and Characterization of Thiol- and Carboxyl-Functionalized Mesoporous Silica Nanoparticles

2017 ◽  
Vol 1142 ◽  
pp. 220-224 ◽  
Author(s):  
Wan Xia Wang ◽  
Yu Wang ◽  
Hua Meng Gong ◽  
Hong Hao Sun ◽  
Ming Xing Liu
Keyword(s):  
Electron Microscopy ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Spherical Shape ◽  
Synthesis And Characterization ◽  
Functionalized Mesoporous Silica ◽  
Transmission Electron ◽  
Ft Ir

The purpose of this article is to synthesize the thiol-and carboxyl-bifunctionalized mesoporous silica nanoparticles (CMS-SH-COOH). CMS-SH-COOH was successfully synthesized by co-condensation and post-grafting methods. Moreover, the particle size and structural properties of CMS-SH-COOH were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR). The obtained results indicated that the CMS-SH-COOH presented a uniform spherical shape with a wormhole arrangement of the mesopores and a relatively narrow paticle distribition. Therefore, the CMS-SH-COOH might be a great potential carrier for the drug delivery system in the future.

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