• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.2053-2065
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• 2003

The current trend in automotive finishing industry is to use more electrostatic rotating bell (ESRB) need space to their higher transfer efficiency. The flow physics related with the transfer efficiency is strongly influenced by operating parameters. In order to improve their high transfer efficiency without compromising the coating quality, a better understanding is necessary to the ESRB application of metallic basecoat painting for the automobile exterior. This paper presents the results from experimental investigation of the ESRB spray to apply water-borne painting. The visualization, the droplet size, and velocity measurements of the spray flow were conducted under the operating conditions such as liquid flow rate, shaping airflow rate, bell rotational speed, and electrostatic voltage setting. The optical techniques used in here were a microscopic and light sheet visualization by a copper vapor laser, and a phase Doppler particle analyzer (PDPA) system. Water was used as paint surrogate for simplicity. The results show that the bell rotating speed is the most important influencing parameter for atomization processes. Liquid flow rate and shaping airflow rate significantly influence the spray structure. Based on the microscopic visualization, the atomization process occurs in ligament breakup mode, which is one of three atomization modes in rotating atomizer. In the spray transport zone, droplets tend to distribute according to size with the larger drops on the outer periphery of spray. In addition, the results of present study provide detailed information on the paint spray structure and transfer processes.

• Korean Institute of Interior Design Journal
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• v.20 no.4
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• pp.37-45
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• 2011

This thesis sets out to study the immanent mechanism of architecture which had classified as external spaces in general. As human controls a space, it controls or manages human's behavior, too. This study is depended on the humanities to analyze a various operation of power in the architectural space. It makes a comparative study of a space-power in a dwelling space through a discourse of Michel Foucault and Jacques Lacan, in particular everyday's microscopic scope. According to analytical results, the space-power of dwelling falls under the influence of a spacial arrangement and subject's desire. It has shown a noticeable characteristics in aspects production & consumption, using behavior, and use value. As it is seen through the aspects of production & consumption, owns of the space-power in a dwelling could not be its subject. We have also understood about a physicalistic furniture at the using behavior, it has a special power unconsciously to control a human's action and lifestyle. And then in the aspects of use value, the centric theme is a television. It lies on the core of space-power in dwelling, because is profoundly related to an innate respect of a dwelling value. In conclusion, so this study has the important meaning in the side to offer some interpretative possibility about the architectural space-power through a microscopic structure.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.11
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• pp.3655-3665
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• 1996

An analytical solution is presented for the conduction-dominated solidification of a binary mixture in a semi-infinite medium. The present approach differs from that of other solution by these four characteristics. (1) Solid fraction is determined from the phase diagram, (2) thermophysical properties in mushy zone are weighted according to the local solid fraction, (3) non-equilibrium solidification can be simulated and (4) the cooling condition of under-eutectic temperature can be simulated. Up to now, almost all analyses are based on the assumption of constant properties in mushy zone and solid fraction linearly with temperature or length. The validation for these assumptions, however, shows that serious error is found except some special cases. The influence of microscopic model on the macroscopic temperature profile is very small and can be ignored. But the solid fraction and average solid concentration which directly influence the quality of materials are drastically changed by the microscopic models. An approximate solution using the method of weighted residuals is also introduced and shows good agreement with the analytical solution. All calculations are performed for NH$_{4}$Cl-H$_{2}$O and Al-Cu system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.225-226
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• 2006

As the technique of high-speed end-milling is widely adopted to machining field. The investigation for microscopic precision of workpiece is necessary for machinability evolution. The environmental pollution has become a big problem in industry and many researcher have investigated in order to preserve the environment. The environmentally conscious machining and technology have more important position in machining process. In the milling process, the cutting fluid has greatly bad influence on the environment. The damaged layer affect mold life and machine parts in machining. In this study, the cutting force, the surface roughness, micro hardness and residual stress is evaluated according to machining environment. Finally, it is obtained that the characteristics of damaged layer in environmentally conscious machining is better than that in conventional machining using cutting fluid.

• Applied Microscopy
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• v.15 no.1
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• pp.1-12
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• 1985

In this study, the pathway and date of migrating Primordial germ cells (PGCs) were observed light microscopically and ultrastructural changes of them during migration were observed by electron microscopic examination. For these purpose, alkaline phosphatase reactions were used for identifying the PGCs and acid phosphatase reactions were used for observing their degenerating activities. Also, effects of actinomycin D on the migration of PGCs were examined. According to these results, at the 9th gestation day, PGCs were observed in the endodermal cells of yolk sac, at the 11th gestation day, they were seen in the hindgut and then entered into the dorsal mesentery by the 13th gestation day. At the 14th gestation day, they were located in the genital ridges. When PGCs were located in the hindgut and genital ridges, the positive reactions of alkaline phosphatase were dominated, but acid phosphatase reactions were limited in all stage except they were in dorsal mesentery. However, these reactions were lessened in case of actinomycin D treatment. By electron microscopic examination, PGCs had pseudopodia, tail process, trailing cytoplasm and nuage as the ultrastructural characteristics. In addition, these morphological features were damaged by actinomycin D treatment.

• Journal of Navigation and Port Research
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• v.31 no.1 s.117
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• pp.107-113
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• 2007

This research addressed the problem of describing how the operating characteristics of passenger car and large vehicle differ qualitatively and quantitatively through the analysis of field survey data. A formulation that estimates passenger car equivalents used in this paper is derived by microscopic headway method. Regression analysis was used to focus on the effect of vehicle type on intervehicular spacings and the modeling technique for the statistical analysis was detailed.

• Journal of Korean Neurosurgical Society
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• v.64 no.2
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• pp.238-246
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• 2021

Objective : To retrospectively analyze the clinical characteristics and surgical experience of 10 adults with spinal extradural meningeal cysts (SEMCs) in the thoracolumbar spine which may further provide evidence for surgical decision-making. Methods : Ten adults with SEMCs in the thoracolumbar spine were surgically treated and enrolled in this study. Clinical manifestations, imaging data, intraoperative findings and postoperative outcome were recorded. Results : Clinical manifestations of SEMCs included motor and sensory dysfunction of the lower limbs and urination and defecation disturbance. The cysts presented as intraspinal occupying lesions dorsal to the spine, ranging from the T8 to L3 level. Defects of eight cases were found on preoperative magnetic resonance imaging (MRI). Selective hemilaminectomy or laminectomy were used to reveal the defect within the cyst, which was further sutured with microscopic technique. The final outcome was excellent or good in seven cases and fair in three cases. No recurrence was observed during follow-up. Conclusion : SEMCs are rare intraspinal cystic lesions. Radiography and MRI are clinically practical methods to assess defects within SEMCs. Selective hemilaminectomy or laminectomy may reduce surgical trauma. Detection and microscopic suturing of the defects are the key steps to adequately decompress the nervous tissue and prevent postoperative recurrence.

• Journal of Biomedical Engineering Research
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• v.44 no.3
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• pp.176-181
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• 2023

During cancer treatment, the patient's response to drugs appears differently at the cellular level. In this paper, an image-based cell phenotypic feature quantification and key feature selection method are presented to predict the response of patient-derived cancer cells to a specific drug. In order to analyze the viability characteristics of cancer cells, high-definition microscope images in which cell nuclei are fluorescently stained are used, and individual-level cell analysis is performed. To this end, first, image stitching is performed for analysis of the same environment in units of the well plates, and uneven brightness due to the effects of illumination is adjusted based on the histogram. In order to automatically segment only the cell nucleus region, which is the region of interest, from the improved image, a superpixel-based segmentation technique is applied using the fluorescence expression level and morphological information. After extracting 242 types of features from the image through the segmented cell region information, only the features related to cell viability are selected through the ReliefF algorithm. The proposed method can be applied to cell image-based phenotypic screening to determine a patient's response to a drug.

• Applied Microscopy
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• v.52
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• pp.6.1-6.5
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• 2022

We examined the morphology of the fertilized egg and the fine structure of fertilized egg envelopes of Poropanchax normani belonging to the family Poeciliidae, also known as Norman's lampeye using light and electron microscopes. The fertilized eggs with narrow perivitelline space were found to be spherical and demersal, additionally containing small oil droplets in the vitelline membrane. Further, a bundle of adhesive filaments was observed to be present on one side of the fertilized egg. These filaments possessed remarkably high elasticity and were approximately 1-3mm in length. The size of the fertilized egg was determined to be about 1.49 ± 0.07mm (n=30). The outer surface appeared smooth, and adhesive filaments originating at different location of the surface of the envelope were found to be distributed around the egg envelope and were joined together to form a single long bundle in scanning electron microscopic observation. A peak-like structure formed of several straight wrinkles was observed around the micropyle. However, the complete structure of the micropyle could not be studied due to the depth at which it was located. Additionally, the total thickness of the egg envelope was ascertained to be approximately12.5-14.5㎛. The egg envelope consisted of two distinct layers, an outer electron dense layer and an inner lamellar layer, further consisting of 10 sublayers of varying thicknesses. Collectively, it was observed that the morphological characteristics of the fertilized egg, fine structures surrounding the micropyle, outer surface, adhesive structure consisting adhesive filaments, and sections of fertilized egg envelope displayed species specificity.

• Journal of Mechanical Science and Technology
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• v.18 no.9
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• pp.1661-1667
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• 2004

An experimental study is performed on atomization characteristics and stable operating conditions for the injection of high viscous waste vegetable oil using an effervescent atomizer with 2 aerator tubes. Consideration is given to the effects of ALR and liquid viscosity on the velocity and mean diameter of the injected droplet. It is found that (i) as ALR increases, the axial velocity of the droplet is increased, while half-velocity width and SMD are decreased regardless of the change in liquid viscosities, (ii) the rate of fine drop distribution occupied in the total spray field is increased with an increase in ALR, and (iii) the effect of viscosity on the atomization characteristics is minor. Consequently, it is expected that the effervescent atomizer will exhibit an excellent atomization performance at the high ALR condition, regardless of liquid viscosities.