• Progress in Medical Physics
• /
• v.9 no.4
• /
• pp.195-200
• /
• 1998

Purpose: When an elongated x-ray field is used for treating a patient, the equivalent- field method is commonly used for the output calculation. This study is intended for investigating potential factors such as, beam quality, field elongation ratio, and depth of measurement, which might effect on the applicability of the equivalent square technique for output calculation. The derivation of a 'rule of thumb' for the application criteria of the equivalent-field method is also aimed. Materials and Methods: Three x-ray beams, 4-, 6- and 10-MV, were employed for this study. Width of the rectangular field was ranged from 5-40 cm and the elongation ratio (length/width) 1:0 to 10:0. An elongation effect was measured in a water phantom at three different depths, dmax, 5-cm, and 10-cm. For an elongated field and its equivalent square field, the output factor was measured and the difference in the output factor were examined between two fields. Results and Discussions: As the elongation ratio increases, a larger discrepancy in outputs is observed between the elongated rectangular field and its corresponding equivalent square field. Output was measured larger for an elongated field than for its corresponding equivalent square field and the maximal difference over 10 % was found. The difference was found larger for the smaller field with the same elongation ratio. The effect of the beam quality and the depth of measurement on the output difference was minimal. Conclusion: Based on the study, there is criteria for the application of the method for output calculation. For the combination of long axis and elongation ratio whose relationship satisfies Elongation ratio < (0.48) (Long axis) - 0.5, the equivalent-field method is valid for output calculation within 2 % for the field whose long axis < 25-cm. For other combinations, instead of using the equivalent-field method, direct output measurement is recommended. This criteria can be applied for 4-10 MV x-ray beams up to 10-cm depth.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.23 no.7
• /
• pp.1064-1072
• /
• 1999

Nylon fabric was grafted for the purpose of the development of detergency against the hemoglobin as a protein soil. By free-radical producing chemical initiator systems the graft using acrylic acid(AA) as a hydrophilic vinyl monomer was performed to change surface energies in the presence of ammonium persulfate(APS) as an initiator and then acrylic acid grafted Nylon was treated with NaOH solution. The surface morphology for Nylon-g-NaAA with changing graft rate were studied by scanning electron microscopy (SEM) The properties of the Nylon such as diameter tenacity elongation contact angle and the hemoglobin removal were also investigated. The diameter of grafted Nylon fiber increased as the graft ratio increased. The tenacity of grafted Nylon also increased with increasing graft ratio up to 15% The elongation however decreased gradually according to graft, The contact angle decreased after graft and alkaline treatment. The amount of hemoglobin on the grafted Nylon increased in proportion to the graft ratio. Hemoglobin was easily removed from grafted Nylon while it was difficult to be removed from ungrafted Nylon. The detergency of hemoglobin for grafted Nylon decreased when the graft ratio exceeded 15% The removal of hemoglobin increased markedly with increasing hemoglobin content and revolution speed. Therefore the removal of hemoglobin was improved due to graft and alkaline treatment.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.11
• /
• pp.3252-3258
• /
• 2010

In this study, the effects of the various parameters of spinning and drawing processes on the properties of polyester full drawn yarn (FDY) prepared by steam processing during high-speed spinning were investigated using several techniques. The wet shrinkage ratio of the FDY was able to be manipulated by controlling the temperature and draw ratio. The FDY made using the steam high speed spinning technique exhibited identical properties (such as tenacity, elongation, and wet shrinkage ratio) to that of regular FDY, made using the spin-draw process. FDY prepared using the steam process during high-speed spinning showed excellent dyeability. The dye pick-up of the polyester yarn spun at high-speed spinning was found to be improved when dyed under an atmospheric pressure of $100^{\circ}C$. This result was the same as regular FDY dyed under a high pressure of $130^{\circ}C$.

• Journal of Korea Spatial Information System Society
• /
• v.11 no.3
• /
• pp.1-8
• /
• 2009

In this study the concepts on the elongation, compactness and equivalent ellipse of catchment plan-forms are applied to the real basins considering their theoretical frameworks. The catchment plan-forms and corresponding equivalent ellipses, obtained from GIS, are inspected on downstream directions. As a result the catchment plan-forms seem to be the population of the basin shapes which come from the random interaction between two conjectures on Hack's law being controversial recently. The ratio of the maximum and minimum inertia moments of the catchment plan-form Ri is more sensitive to evaluate the elongation of the basin shapes than the ratio of the main channel length and diameter of circle which has the same area as the catchment plan-form E. The catchment plan-forms compactness measures show distinct aspects according to their different definitions. These results are caused by the difficulties to quantification of the shapes and the composite consideration with more than two compactness measures and the fractal analysis are therefore required to recover them.

• Textile Coloration and Finishing
• /
• v.9 no.4
• /
• pp.7-19
• /
• 1997

The purpose of the study was to investigate the shrinkage and creep behavior of PET filaments which were prepared at various spinning speeds(3,300, 4,000, 5,000, 6,000, and 7,000m/min) and anneal($120^{\circ}$, 30min & $150^{\circ}$, 40min). In order to determine the shrinkage and creep behavior with the crystallinity change, PET filaments were treated with low(12$0^{\circ}C$, 30min) and high($150^{\circ}$, 40min) temperature conditions with hot air dryer under the constant tension. The results of the study were as follows: as the spinning speed increased, the degree of shrinkage and elongation of the sample treated by wet condition decreased. The sample with 0.01g/d of load under various spinning speeds showed shrinkage behavior and highest shrinkage ratio at $76^{\circ}$ which was Tg of PET. The degree of shrinkage and elongation of the treated sample was less than those of the untreated sample by wet treatment. Especially, there was less degree of shrinkage and elongation of the sample treated by higher temperature condition. In 3,300m/min of spinning speed the draw ratio of undrawn yarn of a mixture of a-axis orientation and c-axis orientation was 2.0, which is similar to the value of the traditional drawn yarn. Finally, there was a big range of shrinkage and elongation by wet treatment in 3,300 m/min of spinning speed.

• Elastomers and Composites
• /
• v.3 no.1
• /
• pp.32-38
• /
• 1968

The physical properties of NR-SBR and NR-BR blends were studied. 1. In blending, tensile strength decreased with increase in synthetic rubber contents. It was most effective when the ratio of NR/Syn. R is 75/25. 2. Tensile strength decreased with order of NR, SBR and BR and modulus after aging is proportional of synthetic rubber contents. 3. Elongation is less influenced by synthetic rubber ratio that on the other hand, the decrease of elongation is proportional to synthetic rubber contents after aging. 4. Hardness decreased with increase in the synthetic rubber contents and on the other hand, the hardness increased after aging.

• Journal of the Korean Applied Science and Technology
• /
• v.17 no.3
• /
• pp.198-202
• /
• 2000

PVA blend films were prepared by solution blending method for the purpose of useful antibiotic polymers. Characteristics properties of blending films such as elongation and tensile strength were determined. Tensile strength and elongation were rapidly reduced as increasing the blending ratio of natural polymer. Blend films were found that phase separation was occured as more than 25wt% increasing the blend ratio of chitosan. Also, The antibiotics of blend films were examined against gram(+) and gram(-) by disk susceptibility test. As a result, kind of blending films to show the highest antibiotics was chitosan 20wt% and the selectivity of mold strain was observed.

• Fashion & Textile Research Journal
• /
• v.6 no.4
• /
• pp.511-514
• /
• 2004

We studied on the bleaching properties of silk fabric by vapor type ozone processing using ozone's strong oxidation instead of 28% $H_2O_2$ chemical treatment. When vapor type ozone processing was directly treated to fabrics retaining water to 50~70% pick up ratio, high concentration ozone was generated 14,000ppm(168 mg/h) approximately and finally its bleaching improved. The fabric's bleaching effect was improved because vapor type ozone generated the highest decomposition to oxidation of surface and inter molecules. The experiment revealed that fabric's bleaching was improved by change of the pick-up ratio of vapor type ozone processing. However, tensile strength and elongation were reduced by increase of time, and the time that was assumed as the most optimized time to minimize the reduction of fabric's tensile strength and elongation as well as maximizing the fabric's bleaching was 30 minutes.

• Horticultural Science & Technology
• /
• v.34 no.1
• /
• pp.55-66
• /
• 2016

This study was carried out to investigate the effect of artificial light sources with different light qualities on the growth and flowering characteristics of a herbaceous long-day plant, Petunia ${\times}$ hybrida Hort. Seedlings of petunia cultivar 'Madness Rose' were potted, acclimated for one week, and grown in a phytotron equipped with tube- and bulb-type fluorescent lamps (FL tube and bulb), tube-type white light-emitting diodes (LED tube), halogen lamps (HL), metal halide lamps (MH), and high pressure sodium lamps (HPS) for 10 weeks. The temperature, photoperiod, and photosynthetic photon flux density (PPFD) in the phytotron were $22{\pm}2^{\circ}C$, 16 h, and $25{\pm}2{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. Light sources combined with HL promoted stem elongation, and plant height and internode length decreased with increasing red to far-red (R:FR) ratio. FL tube + LED tube, HPS, and FL tube promoted branching, whereas plants grown under light sources combined with HL did not have any branches. Days to flowering (from longest to shortest) occurred as follows: FL tube + HL > FL tube + HL > MH > HPS = FL tube + FL bulb > FL tube + LED tube > LED tube > FL tube, indicating that reducing the R:FR ratio of the light sources promoted flowering. Only 20% of plants grown under an FL tube flowered, whereas under all other treatments, 100% of plants flowered. At 10 weeks after treatment, plants grown under HPS and MH had (cumulatively) 12 open flowers, and those grown under FL tube + FL bulb, LED tube, FL tube + LED tube, and HPS treatment had approximately seven flower buds. These results suggest that light sources with low R:FR ratios promote flowering and stem elongation in petunia, but they reduce its ornamental value due to overgrowth and poor branching.

• Journal of the Korea Furniture Society
• /
• v.18 no.4
• /
• pp.268-274
• /
• 2007

Environmentally-friendly polymer composite films were manufactured from cellulose acetate (CA) and polyethylene (PE). To investigate the optimum manufacturing conditions for the composite, various tests such as thermal analysis, surface observation, IR spectra analysis, and elongation ratio of polymer composite films were carried out. The mixing ratio of each element and manufacture condition was found to be very important for the best goods.