• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.397-401
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• 2003

In this work, diamond turning process is used to produce mirror surface on a Al cone. The Al cone as used as a mirror which can reflect a laser beam without scattering and, hence, it is critical to minimize the surface roughness of a Al cone. During diamond turning, feedrate and tool nose radius are changed to investigate characteristics of the ultra precision machined surface of a Al cone. A laser beam of 633 nm is applied to examine the effect of surface roughness on the characteristics of reflectivity. It is found that surface roughness is not significantly affected by feedrate. The main factor influencing surface roughness is tool nose radius. The line patterns of reflected laser beams show that the minimum surface roughness of 0.08 $\mu\textrm{m}$ (Ra) is required to avoid scattering phenomena of reflectivity.

• Korean Journal of Crystallography
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• v.10 no.1
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• pp.1-8
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• 1999

Two conformational isomers of p-tert-butylcalix[4]arene hexanoate were prepared from the reaction of-p-tert-butylcalix[4]arene and hexanoly chloride in the presence of AlCl3 in CH2Cl2 and their structures were determined by NMR spectra and X-ray diffraction as a cone and a 1,3-alternate conformer, respectively. The crystal of cone conformer (C68H96O8·(CH3)2CO) is triclinic, P, a=15.066(1) , b=16.063(1) , c=16.365(1) , α=79.75(2)o, β=109.95(2)o, γ=80.32(0)o, V=3602.7(4) 3, Z=2. The intensity data were collected on Simens SMART diffractometer/CCD area detector. The structure was solved by direct method and refined by least-squares calculations to a final R value of 0.144 for 4638 observed reflections. The molecular conformation is distorted symmetric cone with the flattening A and D phenyl rings. The crystal of 1,3-alternate conformer (C68H96O8·2CHCl3) is orthorhombic, Pca21, a=34.586(5) , b=10.207(3) , c=20.394(4) , V=7199(3) 3, Z=4. The intensity data were collected on an Enraf-Noninus CAD-4 Diffractometer with a graphite monochromated Mo-K radiation. The structure was solved by direct method and refined by least-squares calculations to a final R value of 0.152 for 2241 observed reflections. The molecule has a pseudo mirror symmetric 1,3-alternate conformation.

• Progress in Medical Physics
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• v.3 no.2
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• pp.1-12
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• 1992

For intraoperative radiation therapy using electron beams, a cone system to deliver a large dose to the tumor during surgical operation and to save the surrounding normal tissue should be developed and dosimetry for the cone system is necessary to find proper X-ray collimator setting as well as to get useful data for clinical use. We developed a docking type of a cone system consisting of two parts made of aluminum: holder and cone. The cones which range from 4cm to 9cm with 1cm step at 100cm SSD of photon beam are 28cm long circular tubular cylinders. The system has two 26cm long holders: one for the cones larger than or equal to 7cm diamter and another for the smaller ones than 7cm. On the side of the holder is an aperture for insertion of a lamp and mirror to observe treatment field. Depth dose curve. dose profile and output factor at dept of dose maximum. and dose distribution in water for each cone size were measured with a p-type silicone detector controlled by a linear scanner for several extra opening of X-ray collimators. For a combination of electron energy and cone size, the opening of the X-ray collimator was caused to the surface dose, depths of dose maximum and 80%, dose profile and output factor. The variation of the output factor was the most remarkable. The output factors of 9MeV electron, as an example, range from 0.637 to 1.549. The opening of X-ray collimators would cause the quantity of scattered electrons coming to the IORT cone system. which in turn would change the dose distribution as well as the output factor. Dosimetry for an IORT cone system is inevitable to minimize uncertainty in the clinical use.

• Particle and aerosol research
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• v.13 no.4
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• pp.159-164
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• 2017

The detection efficiency and characteristics of an optical particle counter (OPC), with various sample nozzle outlet diameters, were experimentally investigated. The OPC system, which was built with original design, was made up of a diode laser, two photodetectors, and a variety of optics such as a beam splitter and a concave mirror. The cone-shaped sampling nozzle was designed to be changeable to alter the outlet diameter, within the range of 1 to 3 mm. For samples, sets of polystyrene latex (PSL) standard particle with various sizes of 1 to $3{\mu}m$, were used. As a result, detection efficiency of the OPC greatly decreased with larger nozzle outlet diameter. Moreover, increased nozzle outlet diameter means broader sample flow, thus caused light interference and multiple scattering which results in abnormal high peaks in scattered light signal. The ratio of abnormal peaks to regular signal of single particle increased with larger nozzle outlet diameter.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.6
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• pp.515-520
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• 2012

A daylighting system includes three parts; light collector, light transformer and light distributor. A DBLP(Double blind light pipe) daylighting system consists of a double blind light collector, a mirror duct type light transformer and a prism film light pipe distributor. The double blinds for a light collection are used to track the sun's altitude and azimuth movements throughout the day. Behind both sets of blinds is the light transformer, which is based on a rectangular cone shaped light duct. The light transformer was designed to efficiently deliver the light into the light pipe within a 30 degree radial spread for the efficient light into the distributor. In this study, DBLP system efficiency was simulated, evaluated and optimized by Tracepro as a popular ray trace light design simulation program. The results indicated that DBLP system efficiency evaluated a maximum 22.4% in case of Spring/Fall season solar noon time. While the overall average system efficiency in the morning and afternoon is evaluated about 10%.