Some Studies on Preparation of Large Spray Deposited Aluminium Alloy Tube Preform

In this paper, preparation of large spray deposited aluminum alloy tube was investigated. The shape and particle size distribution of over-sprayed powders together with structure of deposits were analyzed. The results show that the over-sprayed powders resulted from particles missing, spurting and rebounding. The particle size distribution was non-standard normal distribution, the particle size of the great majority was within 150μm and the average size was 50μm. The residual pores in deposits came into being when inter-particle space could not be filled with enough liquid during spray deposition. The as-deposited preform with rough surface was a coalesced bulk of deposited particles. The rotate speed of substrate and scan speed of atomizer together with spray stripe width should satisfy any certain relationship to obtain a qualified tube preform. Substrate preheating and surface treatment and residual stress control were very important for preparing a large preform.

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Effect of Particle Size Distribution on Laser Powder Bed Fusion Manufacturability of Copper

BHM Berg- und Hüttenmännische Monatshefte ◽

10.1007/s00501-021-01107-0 ◽

2021 ◽

Author(s):

Massimiliano Bonesso ◽

Pietro Rebesan ◽

Claudio Gennari ◽

Simone Mancin ◽

Razvan Dima ◽

...

Keyword(s):

Mechanical Properties ◽

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Physical And Mechanical Properties ◽

Powder Bed Fusion ◽

Laser Powder Bed Fusion ◽

Powder Bed ◽

Cooling Channels ◽

Scan Speed

AbstractOne of the major benefits of the Laser Powder Bed Fusion (LPBF) technology is the possibility of fabrication of complex geometries and features in only one-step of production. In the case of heat exchangers in particular, this is very convenient for the fabrication of conformal cooling channels which can improve the performance of the heat transfer capability. Yet, obtaining dense copper parts printed via LPBF presents two major problems: the high reflectivity of 1 μm (the wavelength of commonly used laser sources) and the high thermal conductivity of copper that limits the maximum local temperature that can be attained. This leads to the formation of porous parts.In this contribution, the influence of the particle size distribution of the powder on the physical and mechanical properties of parts produced via LPBF is studied. Three copper powders lots with different particle size distributions are used in this study. The effect on densification from two laser scan parameters (scan speed and hatching distance) and the influence of contours scans on the lateral surface roughness is reported. Subsequently, samples manufactured with the optimal process parameters are tested for thermal and mechanical properties evaluation.

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Effects of Particle Size Distribution on Compacted Density of Lithium Iron Phosphate 18650 Battery

Journal of Electrochemical Energy Conversion and Storage ◽

10.1115/1.4040825 ◽

2018 ◽

Vol 15 (4) ◽

Cited By ~ 3

Author(s):

Lei Chen ◽

Zhenyu Chen ◽

Shuaishuai Liu ◽

Biaofeng Gao ◽

Junwei Wang

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

High Performance ◽

Lithium Iron Phosphate ◽

Iron Phosphate ◽

Specific Discharge ◽

Average Size ◽

Discharge Capacities ◽

Selection Of

The effects of particle size distribution on compacted density of as-prepared spherical lithium iron phosphate (LFP) LFP-1 and LFP-2 materials electrode for high-performance 18650 Li-ion batteries are investigated systemically, while the selection of two commercial materials LFP-3 and LFP-4 as a comparison. The morphology study and physical characterization results show that the LFP materials are composed of numerous particles with an average size of 300–500 nm, and have well-developed interconnected pore structure and a specific surface area of 13–15 m2/g. For CR2032 coin-type cell, the specific discharge capacities of the LFP-1 and LFP-2 are about 165 mAh/g at 0.2 C. For 18650 batteries, results indicate that the LFP-3 material has the highest compacted density of 2.52 g/cm3 at a concentrated particle size distribution such as D10 = 0.56 μm, D50 = 1.46 μm, and D90 = 6.53 μm. By mixing two different particle sizes of LFP-1 and LFP-2, the compaction density can be increased significantly from 1.90 g/cm3 to 2.25 g/cm3.

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UKURAN PARTIKEL DAN KONFORMASI KRISTAL ZEOLIT-A HASIL SINTESIS DENGAN PENAMBAHAN TETRAPROPILAMMONIUM HIDROKSIDA (TPAOH)

REAKTOR ◽

10.14710/reaktor.15.2.132-138 ◽

2014 ◽

Vol 15 (2) ◽

pp. 132 ◽

Cited By ~ 1

Author(s):

Nurul - Widiastuti ◽

Farhanah Thalib ◽

Didik Prasetyoko ◽

Hamzah Fansuri

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Electrostatic Interactions ◽

Distribution Analysis ◽

Zeolite A ◽

Zeolite Framework ◽

Tetrapropylammonium Hydroxide ◽

Ft Ir ◽

Average Size

Abstract PARTICLE SIZE AND CRYSTAL CONFORMATION OF SYNTHESIZED ZEOLITE-A WITH TETRAPROPYLAMMONIUM HYDROXIDE (TPAOH) ADDITION. The aims of this research is to study the effect of tetrapropylammonium hydroxide (TPAOH) concentration in the synthesis of zeolite A to its physical characteristics such as crystallinity, crystal conformation and average crystal size. The zeolite A was synthesized with composition 3.165 Na2O : 1.000 Al2O3 : 1.926 SiO2 : 128 H2O : x TPAOH where x was 0; 0.0385; 0.0577; 0.0770; 0.1540 and 4.1602. The zeolite was crystalized under hydrothermal condition in a stainless steel autoclave at 100°C for 5 hours. The resulting crystal was washed with distilled water until pH 8 and then dried in an oven at 80oC for 24 hours. FT-IR and XRD analysis results show that the synthesized zeolite A at x = 4.1602 has the lowest crystallinity. It is estimated due to the mass of TPAOH was four times higger than the mass of zeolite framework components (Si and Al). SEM and PSD (Particle Size Distribution) analysis results show that TPAOH concentration affected the crystal conformation and the average size of zeolite A particles. The formation of chained crystal conformation was caused by the electrostatic interactions between TPA+ and negatively charge of zeolite framework. In addition, the particel size of the synthesized zeolite A at x = 0.1540 was 2.024 µm which was smaller than the particel size of the synthesized zeolite A without TPAOH, which was 3.534 µm. Keywords: average size of particles; crystal conformation; TPAOH; zeolite A Abstrak Penelitian ini bertujuan untuk mempelajari pengaruh konsentrasi TPAOH (Tetrapropilamonium hidroksida) dalam sintesis zeolit A terhadap sifat fisikanya yang meliputi kekristalan, konformasi kristal dan ukuran rata-rata kristal yang terbentuk. Pada penelitian ini zeolit A disintesis dengan komposisi 3,165 Na2O : 1 Al2O3 : 1,926 SiO2 :128 H2O: x TPAOH. Konsentrasi TPAOH divariasikan dengan nilai x adalah 0; 0,0385; 0,0577; 0,0770; 0,1540 dan 4,1602. Metode hidrotermal digunakan dalam penelitian ini dengan kondisi suhu hidrotermal 100°C dan waktu kristalisasi selama 5 jam dengan pH pencucian 8. Hasil karakterisasi menggunakan FT-IR (Fourier Transform – Infrared Spectroscopy) dan XRD (X-Ray Diffraction) menunjukkan bahwa zeolit A yang disintesis dengan x = 4,1602 memiliki kekristalan terendah. Hal ini diperkirakan terjadi karena masa TPAOH yang digunakan empat kali lebih besar daripada masa penyusun zeolit (Si dan Al). Berdasarkan hasil karakterisasi menggunakan SEM (Scanning Electron Microscopy) dan PSD (Particle Size Distribution), dapat diketahui bahwa TPAOH berpengaruh terhadap konformasi kristal dan rata-rata ukuran kristalnya. Terbentuknya konformasi kristal seperti rantai disebabkan oleh adanya interaksi elektrostatik antara muatan positif pada TPA+ dan muatan negatif dari kerangka zeolit. Zeolit A yang disintesis dengan x = 0,1540 memiliki ukuran partikel rata-rata 2,024 µm yang lebih kecil dari daripada zeolit A tanpa TPAOH yaitu sebesar 3,534 µm. Kata kunci : ukuran partakel rata-rata; konformasi kristal; TPAOH; zeolite A

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Justification of parameters and technology of drilling and blasting operations to ensure the required lumpiness

Горная промышленность ◽

10.30686/1609-9192-2021-3-110-115 ◽

2021 ◽

pp. 110-115

Author(s):

V.V. Egorov ◽

A.N. Volokitin ◽

N.V. Ugolnikov ◽

A.V. Sokolovsky

Keyword(s):

Particle Size ◽

Rock Mass ◽

Particle Size Distribution ◽

Size Distribution ◽

Design Stage ◽

Production Cycle ◽

Lump Size ◽

Optimal Technology ◽

Average Size ◽

The Cost

The practice of mining and blasting operations both during the development of a mineral deposits, and at the mine design stage, often involves the question of selecting the technology options and operation parameters. Virtually all recommendations for selecting the best production option are based on minimizing the total costs for the entire technological cycle of mining activities. In most cases the optimal technology and parameters of mining and blasting operations depend on the commercial, maximum permissible and average size of the blasted rock mass, which are determined by the type and capacity of the mining haulage equipment. Therefore, the total costs will mainly depend on the commercial or average lump size and the cost of mining transport equipment. The article presents a methodology to select the best technological option for the drilling and blasting operations to obtain the optimal lumpiness (particle-size distribution) of the blasted rock. The optimal range of lumpiness is defined by the total minimum costs for the entire production cycle of mining and processing of minerals. In order to select a rational technology of drilling and blasting and to calculate their parameters it is proposed to take into account the integral criteria of lumpiness in addition to the average lump size. For this purpose, we studied the particle size distribution in the rock mass and in the muck piles.

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PREPARATION OF POLYMERIC NANOPARTICLES BY FLOW ULTRASONIC EMULSIFICATION

Тонкие химические технологии ◽

10.32362/2410-6593-2016-11-6-63-67 ◽

2016 ◽

Vol 11 (6) ◽

pp. 63-67

Author(s):

Yu. M. Domnina ◽

S. A. Kedik ◽

V. V. Suslov ◽

E. A. Shnyak ◽

S. S. Kryukova

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Polymeric Nanoparticles ◽

Average Particle Size ◽

Average Diameter ◽

Flow Mode ◽

Average Particle ◽

One Step ◽

Average Size

The work is dedicated to the production of polymer suspensions using ultrasonic dispergation in a flow mode. An apparatus was designed on the basis of a Russian flow ultrasonicator. The applicability of this apparatus for obtaining aqueous dispersions of polymeric micro- and nanoparticles by means of one-step emulsification followed by solvent extraction / evaporation was demonstrated. The influence of the process parameters on the characteristics of the obtained suspensions was studied. The particle size distribution and the average size of the resulting particles were evaluated by using Delsa Nano S, Beckman Coulter laser analyzer (USA). The dependence of the average diameter of the suspension particles on the stabilizer concentration and on the change of the phases feed rate was shown. When polyvinyl alcohol was used as a stabilizer in the concentration range 0.5-2%, the average particle size was 30-400 nm. The feed rates of the aqueous and organic phases affect the nature of the particle size distribution.

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STUDYING OF THE CHEMICAL COMPOSITION OF THE POWDER FROM BROCCOLI CABBAGE AS RAW MATERIAL FOR PRODUCTION OF FUNCTIONAL FOODS

Известия вузов. Пищевая технология ◽

10.26297/0579-3009.2019.1.5 ◽

2019 ◽

Author(s):

Т.И. КРЯЧКО ◽

В.Д. МАЛКИНА ◽

В.В. МАРТИРОСЯН ◽

С.А. СМИРНОВА ◽

Н.А. ГОЛУБКИНА ◽

...

Keyword(s):

Particle Size ◽

Chemical Composition ◽

Particle Size Distribution ◽

Size Distribution ◽

Raw Materials ◽

Raw Material ◽

Size Of Particles ◽

Average Size ◽

Food Staples ◽

Physical And Chemical

Представлен сравнительный анализ гранулометрических, органолептических и физико-химических показателей качества порошков из капусты брокколи, полученных конвективным и лиофильным способами сушки из отечественного сорта Тонус и импортного гибрида Маратон F1. По показателям гранулометрического состава исследованные образцы порошков конвективной и лиофильной сушек относятся к грубодисперсным системам. Меньшие значения среднего размера частиц (0,14–0,15 мм) имеют порошки из брокколи гибрида Маратон F1 двух способов сушки. Проведен анализ морфологии частиц порошков из капусты брокколи по характеристикам распределения вытянутости, гладкости и яркости. По гранулометрическому составу и морфологии частиц из порошков капусты брокколи сорта Тонус и гибрида Маратон F1существенных различий не обнаружено. Органолептические показатели – вкус, запах, цвет порошков капусты брокколи сорта Тонус и гибрида Маратон F1соответствовали использованному сырьевому источнику. Содержание белков, жиров и углеводов в порошках, полученных конвективным и лиофильным способами сушки, практически одинаково. Установлена сохранность витамина С в порошках при переработке свежей капусты: сорта Тонус в среднем на 26%, гибрида Маратон F1на 53,5%. Сохранность полифенольных соединений в порошках из брокколи сорта Тонус и гибрида Маратон F1, выработанных двумя способами сушки, составила 57,8–67,8%. Комплексные исследования показали, что порошки из капусты брокколи, выработанные из отечественного и импортного сырья, имеют ценный химический состав, что позволяет отнести их к перспективному продовольственному сырью для использования в технологиях функциональных продуктов питания. The comparative analysis of granulometric, organoleptic and physical and chemical indicators of quality of powders of cabbage of the broccoli received convective and liofilny by ways of drying from a domestic grade the Tonus and an import hybrid Maraton F1is submitted. On indicators of particle size distribution the studied samples of powders of convective and liofilny drying belong to grubodispersny systems. Smaller values of the average size of particles of 0,14–0,15 mm have hybrid broccoli powders Maraton of F1 of two ways of drying. The analysis of morphology of particles of powders of cabbage of broccoli according to characteristics of distribution of elongation, smoothness and brightness is carried out. On particle size distribution and morphology of particles of powders of cabbage of broccoli of a grade the Tonus and a hybrid Maraton F1of essential distinctions isn’t revealed. Organoleptic indicators – taste, a smell, color of powders of cabbage of broccoli of a grade the Tonus and a hybrid Maraton of F1corresponded to the used raw source. Content of proteins, fats and carbohydrates in the powders received convective and liofilny by ways of drying were almost close. The safety of vitamin C in powders when processing fresh cabbage is established: grades the Tonus on average 26%, a hybrid Maraton F1– 53,5%. Safety of polyphenolic connections in grade powders the Tonus and a hybrid Maraton of F1developed on two ways of drying made 57,8–67,8%. Complex researches have shown that the powders of cabbage of broccoli produced from domestic and import raw materials have the valuable chemical composition that allows to carry them to perspective food staples for use in technologies of functional food.

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