• Geomechanics and Engineering
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• v.15 no.3
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• pp.811-822
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• 2018

Chip size distribution can be used to evaluate the cutting efficiency and to characterize the cutting behavior of rock during cutting and fragmentation process. In this study, a series of linear cutting tests was performed to investigate the effect of cutting conditions (specifically cut spacing and penetration depth) on the production and size distribution of rock chips. Linyi sandstone from China was used in the linear cutting tests. After each run of linear cutting machine test, the rock chips were collected and their size distribution was analyzed using a sieving test and image processing. Image processing can rapidly and cost-effectively provide useful information of size distribution. Rosin-Rammer distribution pamameters, the coarseness index and the coefficients of uniformity and curvature were determined by image processing for different cutting conditions. The size of the rock chips was greatest at the optimum cut spacing, and the size distribution parameters were highly correlated with cutter forces and specific energy.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.704-705
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• 2006

Discrete element analysis is used to map various log-normal particle size distributions into measures of the in-sphere pore size distribution. Combinations evaluated range from monosized spheres to include bimodal mixtures and various log-normal distributions. The latter proves most useful in providing a mapping of one distribution into the other (knowing the particle size distribution we want to predict the pore size distribution). Such metrics show predictions where the presence of large pores is anticipated that need to be avoided to ensure high sintered properties.

• Journal of Industrial Technology
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• v.21 no.B
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• pp.149-153
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• 2001

A study on the particle growth in $TEOS/O_2$ plasma was performed, and particle size and its distribution was measured by the electrical aerosol analyzer (EAA), light scattering particle size analyzer and the particle size was also determined by SEM. The effects of process variables such as total gas flow rate, reactor pressure, supplied power and initial reactant concentration on the particle growth were investigated. From the EAA results, the particle size distribution is divided into three groups of the cluster size and the small and large size particles. The particle size distribution measured by the light scattering particle size analyzer becomes bimodal, because the cluster size particles smaller than 20 nm in diameter cannot be detected by the light scattering particle size analyzer. The size of particles measured by the light scattering particle size analyzer is in good agreements with those by the SEM. Also we could understand that the particle formation is very sensitive to the changes of reactor pressure and reactant concentration. As the total gas flow rate increases, the particle size decreases because of the shorter residence time. As the reactor pressure, or the reactant concentration increases, the particle concentration increases and the particles grow more quickly by the faster coagulation between particles.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.35
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• pp.39-46
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• 1995

This study is to find the optimal lot size method in the distribution system. In general, the lot size methods used in the distribution system is the same as the methods of the MRP system. The lot size methods used in this study are LFL, EoQ, LTC and POQ.. Resulting in case study, LTC is the optimal lot size method in the distribution system. In distribution system, VRP and VSP shall be investgated.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.267.2-267.2
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• 2013

In the citrate reduction method of gold nanoparticle (AuNP) synthesis, pH of the reaction mixture can have a considerable impact on the size and size distribution of AuNPs. In this work, effects of pH variation upon the size and its distribution were examined systematically. As the initial pH was change from 5.5 to 10.5, it showed an optimal pH around 7.5. At this pH, both of the size and the size distribution showed their minimum values, which was verified by transmission electron microscopy and UV-vis spectroscopy. This occurrence of optimal pH was discussed with the results of in situ monitoring pH during the reaction of AuNP synthesis.

• Textile Coloration and Finishing
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• v.15 no.5
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• pp.327-332
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• 2003

In this study, the polyurethane microcapsules for non-aqueous dyeing containing iron oxide and disperse dyes were prepared by in-situ polymerization method using hexamethylene diisocyanate(HDI) with ethylene glycol(EG). And the size, shape, and particle size distribution of microcapsules prepared were investigated. The size and shape of microcapsule were observed by optical microscope and scanning elecron microscope. The particle size distribution was analyzed by particle size analyzer. The microcapsule size and its distribution were largely effected by the existance of surface active agent in the system. When a surfactant did not exist in the system, the size distribution of microcapsules prepared was much uneven. By adding a surfactant, this phenomenon was disappeared. And the size of microcapsule was also effeced by the hydrophobicity of core material(disperse dye). It was considered due to the difference of dispersity of core materials. And the size of microcapsule prepared was inversely proportional to the stirring speed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.7 s.262
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• pp.611-619
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• 2007

In this study, the droplet size distribution of a slit injector at different surrounding conditions, such as air flow and fuel temperature, were investigated. Phase Doppler anemometry (PDA) was utilized to investigate the initial droplet size distribution and the effect of fuel temperature and air flow on droplet size distribution. The entrained air motion was also evaluated by the temporal velocity profile of droplets. When the air flow velocity increased, the small droplets were more entrained to the upper and central parts of the spray and this tendency was confirmed by plotting the temporal velocity profile of droplets. This entrainment of small droplets at high airflow velocities caused relatively small mean droplet size at upper and central parts of the spray and the large mean droplet size at downstream and edge of the spray, compared to that of low airflow velocities. The total mean droplet size, obtained by averaging the size of all droplets measured at all test locations, decreased when the high airflow velocities were applied. The increased fuel temperature, with an airflow velocity of 10m/s, caused reduced droplet size at all test locations. However, the decreased value of mean droplet size at high fuel temperatures was relatively higher at upper parts of the spray, compared to downstream, as a result of enhanced entrainment of small droplets to upper parts of the spray.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.104-109
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• 2001

The time to measure the size distribution using Condensation Nuclei Counter(CNC) and Differential Mobility Analyzer(DMA) can be shortened by classifying particles ramping the DMA voltage exponentially and continuously. In measurement, particles sampled at different time are mixed together going through sampling tube and CNC. Because the size distribution is inversed by using detector responses to sampling time intervals in this accelerated method, the mixing effects give inversion errors to the size distribution. The mixing effects can be considered by appling the transfer function with mixing effects to the data inversion. The inversion considering this effects gives birth to the size distribution shifted to the opposite direction of the size scanning.

• Polymer(Korea)
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• v.25 no.5
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• pp.744-753
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• 2001

One of the most important factors which affect the impact strength of high impact polystyrene (HIPS) is the rubber-phase particle size and size distribution. In this study, HIPS was prepared from a batch reactor to observe the influence of reaction conditions such as rubber content, agitation speed and prepolymerization time on the particle size and size distribution. Measurements concerning the particle size distribution were conducted using a particle size analyzer. Due to swelling, the particle suspended in toluene increases in size with lower heat-treatment temperature and shorter heat-treatment time, while the particle in methyl ethyl ketone shows quite reasonable size without any effort of heat-treatment. As rubber content increases, the average particle size increases substantially, but the increase in agitation speed at lower rubber contents does not have much influence on the size. However, the polystyrene-phase particles occluded in rubber-phase become more uniform as agitation speed increases. Longer prepolymerization time produces rubber-phase particles with narrower particle size distribution.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.6
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• pp.923-934
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• 2021

Most apparel products have national standards for sizing; however, for gloves, national sizing standards have not yet been established. This study aims to analyze children's hand dimensions and propose a size specification for children's gloves that shows children's hand-related size information. Among the 3D measurements of sixth Size Korea Project, the measurement data of 19 dimensions related to the hands of 1,057 boys and girls aged 7-13 years old were analyzed. The distribution and growth trend of hand measurements for boys and girls demonstrated considerable mean differences and distribution trends by gender and age as per hand dimensions, which leads to the conclusion that it is necessary to show these results in the children's glove design. Based on these results, the cross-distribution maps of children's hand length and hand circumference were drafted; furthermore, the distribution relationship with an adult hand size was identified. Based on the distribution of hand sizes, the distribution of adult hand sizes overlapped with children's hand sizes was verified, and children's glove size specifications were presented. The results can be used as useful data such as measures for setting the size range and sizing system for children's gloves.