• Journal of the Korean Wood Science and Technology
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• v.46 no.4
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• pp.346-354
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• 2018

Kemenyan resin from Styrax sumatrana is a unique non-timber forest product (NTFP) native from Sumatera Island, Indonesia. It possesses a wide range of applications in the pharmaceutical, perfume, and cosmetics industries. In this paper, six kemenyan resin samples were investigated to evaluate their free radical scavenging activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) reagent. The kemenyan resin samples, which originated from North Tapanuli, Pakpak Bharat, and Humbang Hasundutan, showed high antioxidant activity with $IC_{50}$ < 16 mg/L. The antioxidant activity of common kemenyan resin constituents, i.e., cinnamic acid, ethyl cinnamate, gallic acid, and vanillin was also investigated as positive control, although they exhibited lower antioxidant activity ($IC_{50}$ < 1000 mg/L), except for gallic acid ($IC_{50}$ = 5,23 mg/L). The total phenolic and flavonoid contents (TPC and TFC) for all samples were 44-66 mg gallic acid equivalents (GAE)/g sample and 143-160 mg quarcetin equivalents (QE)/g sample. The results revealed that kemenyan resin has high potency as an antioxidant and could be used as a natural antioxidant resource.

• Journal of the Korean Wood Science and Technology
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• v.46 no.4
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• pp.315-322
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• 2018

Bamboo culm comprises internodes and nodes and is tapered from the bottom to the top. Anatomically, bamboo culm comprises vascular bundles and parenchymal base tissue. The gross anatomical structure of a transverse section of any culm internode is determined by the shape, size, arrangement, and number of vascular bundles. The purpose of this research was to examine the morphology of culm and the distribution and shape of vascular bundles in Ampel bamboo (Bambusa vulgaris). Bamboo culms were harvested from the base. Test samples were obtained from a central 2-cm long segment of each internode across the entire length of the culm. Results showed an uneven spread of vascular bundles in the internode cross-section. Transitioning from the outer to the inner layer of the internode, the number of vascular bundles per unit area decreased and their shape was variable. The size of vascular bundles in the middle layer of the internode was greater than that of those in the outer and inner layers. The shape of vascular bundles was circular in the outer layer, which gradually transformed into vertical oval toward the middle layer and horizontal oval toward the inner layer. Vascular bundles were of type III and IV in the bottom of the culm and type III in the middle to the top of the culm.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.67-74
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• 2001

This paper presents the Safe Shutdown Earthquake(SSE) input motion for the seismic design of the Advanced Power Reactor 1400(APR1400). The Design Ground Response Spectra(DGRS) far the SSE is based on the design spectrum specified in regulatory Guide(RG) 1.60 of U.S. Nuclear Regulatory Commission(US NRC), anchored to a Peak Ground Acceleration(PGA) of 0.3g and enriched in the high frequency range. This SSE seismic input motion is to be applied to the seismic analysis as the free-field seismic motion at the ground surface of both the rock and generic soil sites fur APRI1400. The enrichment for APR1400 seismic input motion is performed considering the current US NRC regulations, the seismic hazard studies performed by the Lawrence Livermore National Laboratory (LINL) and Electric Power Research Institute(EPRI) for the Central and Eastern United States nuclear power plant sites, and the seismic input motions used in the design certifications of the three existing U.S. advanced standard plants. It is represented by a set of DGRS and the accompanying Target Power Spectral Density(PSD) Function in both the horizontal and vertical directions.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.103.1-103.1
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• 2014

Due to their excellent optical and electrochemical properties, conjugated polymers have attracted much attention over the last two decades and employed to opto-electrical devices. In particular, conjugated polymers possess many attractive features that make them suitable for a variety of sensing task. For example, their delocalized electronic structures can be strongly modified by varying the surrounding environment, which significantly affected molecular energy level. In other word, conjugated polymers can detect and transduce the environmental information into a fluorescence signal. Conjugated polymers also display amplified quenching compared to small molecule counterparts. This amplified fluorescence quenching is attributed to the delocalization and migration of the excitons along the conjugated polymer backbones. Long backbones of conjugated polymer provide the transporting path for electron as a conduit, allowing that excitons migrate rapidly into quencher site along the backbone. This is often referred to as the molecular wire effect or antenna effect. Moreover, structures of conjugated polymers can be easily tailored to adjust solubility, absorption/emission properties, and regulation of electron/energy transfer. Based on this versatility, conjugated polymers have been utilized to many novel sensory platforms as a promising material. In this tutorial, I will highlight a variety of fluorescence sensors base on conjugated polymer and explain their sensory mechanism together with selected examples from reference literatures.

• The Journal of Internal Korean Medicine
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• v.25 no.4
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• pp.221-226
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• 2004

Objective : This study was designed to evaluate the effects of oriental medicine therapy on a normal pressure hydrocephalus patient Methods : The clinical data was analyzed on a patient with normal pressure hydrocephalus whose main symptoms were gait apraxia, dementia and urinary incontinence, The patient was admitted to the internal medicine department of KyungWon university In-cheon Oriental Medical Hospital, on April 19, 2004 and remained until Apri 30, 2004. He was treated with herbal medicine(Oryung-San), acupuncture and moxa therapy. Results : After treatment, improvement was seen in gait apraxia, dementia and urinary disturbance. Conclusion : The study suggests that oriental medicine therapy is significantly effective in the treatment of normal pressure hydrocephalus.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.539-550
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• 2016

The objective of this research was to evaluate physical and mechanical properties of three species of Styrax woods from North Tapanuli in Indonesia. The woods were more than 15 years old. Physical properties such as specific gravity, green moisture content, and volume shrinkage were determined by the procedures based on BS-373 standard for small clear specimen. Furthermore, mechanical properties, including modulus of rupture, modulus of elasticity, compression parallel to grain and hardness were also tested according to the standard. Along the stem direction, the edge section had better properties compared with those near the pith section. And the base section had also better properties than upper section. Based on the specific gravity, all of the Styrax woods in this research were classified into III-IV strength classes. A good dimensional stability was demonstrated by the value of the tangential and radial ratio which reached one. With the consideration of the mechanical properties, Styrax woods were suitable use for raw materials of light construction, furniture and handy craft.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.503-512
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• 2020

Using Na₂CO₃ versus NaCl as chemical activator, we compared the quality of activated carbon produced from oil palm fronds as raw material. These activators were selected for comparison because both are readily available and are environmentally friendly. In the manufacturing, we used Indonesian National Standard (SNI 06-3730-1995) parameters. For the quality comparison, we determined activated-carbon yield, moisture, ash, volatiles, and fixed-carbon contents; and adsorption capacity of iodine. The best characteristics, assessed by morphological surface analysis and Fourier transform infrared (FTIR) spectral analysis, were observed in the carbon activated by Na₂CO₃ at an activator concentration of 10% and carbonization temperature of 400 ℃. The results were as follows: activated-carbon yield, 84%; water content, 8.80%; ash content, 2.20%; volatiles content, 14.80%; fixed-carbon content, 68.60%; and adsorption capacity of iodine, 888.51 mg/g. Identification using the FTIR spectrophotometer showed the presence of the functional groups O-H, C=O, C=C, C-C, and C-H in the Na₂CO₃-activated carbon.

• The Journal of Korean Obstetrics and Gynecology
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• v.18 no.3
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• pp.250-257
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• 2005

Purpose : This study was designed to evaluate the effects of oriental medicine therapy on a patient of metrorrhagia and metrostaxis with endometrial polyp. Methods : The clinical data was analyzed on a patient of metrorrhagia and metrostaxis with endometrial polyp whose main symptoms were dysfunctional uterine bleeding. A 27-year-old female who had been treated hormone replacement therapy for dysfunctional uterine bleeding at a obstetrics and gynecology became worse, so refused any more hormone replacement therapy and visited Dongsin university oriental hospital. The patient was admitted to the obstetrics and gynecology department of Dongsin university Oriental Medical Hospital, on Febrary 23, 2004 and remained until Apri 11, 2005. we treated the patient with a herb-medication, acupunture therapy, moxa therapy and etc. Results : After treatment, improvement was seen in dysfunctional uterine bleeding, generalized weakness. Conclusion : The study suggests that oriental medicine therapy is significantly effective in the treatment of metrorrhagia and metrostaxis with endometrial polyp.

• Journal of the Korean Wood Science and Technology
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• v.48 no.1
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• pp.76-85
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• 2020

This study was conducted to analyze the application of boron compounds, methyl methacrylate (MMA), and heat treatment (HT) on changes in the density, moisture content, and flexural properties of samama (Anthocephalus macrophyllus) wood. Samama wood was impregnated with borax (BX) and boric acid (BA) using a pressure method at 5 atm for 4 h. Afterwards, the wood was impregnated with MMA at the same pressure and duration. Finally, the samama wood was given HT at 90 ℃ and 180 ℃. The results indicate that there was a weight gain of 93.4% in the wood impregnated using BA and MMA monomer and HT at 90 ℃. Consequently, the wood's density increased by 82.3%. Increased MOE and MOR percentages of 32.2% and 29.4%, respectively, were also found. HT at 180 ℃ degraded the wood components and MMA, and consequently, the density, MOE, and MOR also decreased. The wood impregnated by BX, BA, and MMA, and subjected to HT also had decreased moisture content (MC). This research recommends that the application of boron (BX, BA) should be combined with an MMA monomer and HT at 90 ℃ as an alternative method to improve samama wood quality. If darker color is preferable, HT should be conducted at 180 ℃.

• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.239-248
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• 2019

This research presents an improvement of the physical and mechanical properties of composite board (com-ply) made of Oriented Strand Board (OSB) coated with wood veneer of Pine (Pinus merkusii), Avocado (Persea Americana) and Mahogany (Swietenia mahogany). 1.5 mm thick veneers of those three wood types were adhered to the surface of OSB using two adhesive types: epoxy and isocyanate. The adhesive with the glue spread of $250g\;m^{-2}$ applied using single glue line was spread and then cold pressed with the pressure of $15kg\;cm^{-2}$ for 3 hours. The research result showed an improving dimension stability of com-ply, but not found on all parameters of physical property test. The moisture content seemed to be influenced by the com-ply type, yet not related to its thickness swelling, water absorption and linear expansion. The exception took place in the parallel linear expansion when immersed for 2 hours. The highest to the lowest increases of MOE and MOR were consecutively found on OSB coated with wood veneer of Pine, Mahogany and Avocado. However, the increases were statistically insignificant. The highest increasing screw hold power was found at the com-ply type AE (avocado veneer and epoxy adhesive) that was by 28%.