• Journal of the Korean Wood Science and Technology
• /
• 제48권1호
• /
• pp.76-85
• /
• 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 ℃.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
• /
• pp.24.2-24.2
• /
• 2009

We present the results of new CCD photometry for the contact binary BX Peg, made during three successive months beginning on September 2008. As do historical light curves, our observations display an O'Connell effect and the November data by themselves indicate clear evidence for very short-time brightness disturbance. For these variations, model spots are applied separately to the two data set of Group I (Sep.--Oct.) and Group II (Nov.). The former is described by a single cool spot on the secondary photosphere and the latter by a two-spot model with a cool spot on the cool star and a hot one on either star. These are generalized manifestations of the magnetic activity of the binary system. Twenty light-curve timings calculated from Wilson-Devinney code were used for a period study, together with all other minimum epochs. The complex period changes of BX Peg can be sorted into a secular period decrease caused dominantly by angular momentum loss due to magnetic stellar wind braking, a light-travel-time (LTT) effect due to the gravitational effect of a low-mass third companion, and a previously unknown short-term oscillation. This last period modulation could be produced either by a second LTT orbit with a period of about 16 yr due to the existence of a fourth body or by the effect of magnetic activity with a cycle length of about 12 yr.

• 한국전기전자재료학회논문지
• /
• 제32권3호
• /
• pp.196-200
• /
• 2019

In this study, photoluminescence (PL) analysis was performed to evaluate the optical properties of commercial ZnO substrates. Particular attention was paid to the bound exciton (BX) luminescence, which is usually the strongest emission intensity of commercial substrates. At 15 K, PL analysis revealed that the BX peak due to donor-type impurities (donor-bound-exciton; DX) dominated, while two-electron satellite (TES) emission, donor-accepter pair (DAP) emission, and LO-phonon replica emission were also observed. The impurity concentration of the ZnO substrate was determined to be $10^{15}$ to $10^{16}/cm^3$ by examination of the temperature variation of DAP, while the half width and intensity change of the luminescence revealed that the temperature change of BX can be interpreted almost the same as the analysis of free-exciton emission.

• 한국식품영양학회지
• /
• 제27권5호
• /
• pp.971-978
• /
• 2014

Investigation of the quality characteristics of Takju brewing mashes prepared with several different yeasts was carried out during the 42-day brewing process, including examination of titratable acidity, amino acid content, sugar contents, alcohol contents, pH, reducing sugar, yeast population, lactic acid bacteria, and sensory evaluation. Fermivin yielded the highest titratable acidity, while la parisienne had the lowest. Fermivin also had the highest value of amino acid content (14.33%), while other yeasts shows period tended to increase over exclude Instaferm and Song chun. The amount of sugars in instaferm ($11.33^{\circ}Bx$) and instaferm red ($10.53^{\circ}Bx$) were higher than those in La parisienne red and Song chun ($9.57^{\circ}Bx$). The alcohol contents of instaferm was the highest value (15.20%) while the alchol content of the other yeasts tended to increase the fementation period. Fermivin had the highest pH at $12^{th}$ day among the yeasts(4.02), Instaferm red had the lowest pH among the yeasts (3.87) while safbrew wb-06 had the highest reducing sugar content(117.60 mg/mL). Instaferm obtained the highest preference in the sensory evaluation for all items.

• Biomolecules & Therapeutics
• /
• 제31권1호
• /
• pp.68-72
• /
• 2023

Pancreatic cancer is one of the most fatal cancers with a poor prognosis. Standard chemotherapies have proven largely ineffective because of their toxicity and the development of resistance. Therefore, there is an urgent need to develop novel therapies. In this study, we investigated the antitumor activity of MS-5, a naphthalene derivative, on BxPC-3, a human pancreatic cancer cell line. We observed that MS-5 was cytotoxic to BxPC-3 cells, as well as inhibited the growth of cells in a concentration- and time- dependent manner. Flow cytometry analysis revealed that the percentage of annexin V-positive cells increased after MS-5 treatment. We also observed cleavage of caspases and poly (ADP-ribose) polymerase, and downregulation of Bcl-xL protein. Flow cytometry analysis of intracellular levels of reactive oxygen species (ROS) and mitochondrial superoxide suggested that MS-5 induced the generation of mitochondrial superoxide while lowering the overall intracellular ROS levels. Thus, MS-5 may be potential candidate for pancreatic cancer treatment.

• 한국전자통신학회논문지
• /
• 제8권11호
• /
• pp.1749-1754
• /
• 2013

주기가 $2^n-1$인 이진수열은 부호이론, CDMA와 같은 통신시스템과 암호체계 등 많은 분야에서 폭넓게응용되고 있다. 본 논문에서는 n=2m, m=4k($k{\geq}2$)이고 $d=3{\cdot}2^m-2$일 때 생성되는 비선형 이진수열의 상호상관관계의 빈도를 분석하기 위해 $GF(2^n)$ 위에서 방정식 $x^5+bx^3+b^{2^m}x^2+1=0$의 해의 유형에 대하여 분석하고 서로 다른 해의 개수를 결정하는 알고리즘을 제안한다.

• 한국식품과학회지
• /
• 제49권2호
• /
• pp.222-227
• /
• 2017

본 연구에서는 금 나노입자 용액을 생장하는 6년근 인삼에 직접 시비해서 금 나노입자가 전이된 황금인삼을 열수 추출하여 총페놀 함량, 총플라보노이드 함량, 산화방지능 및 신경세포 보호능을 평가하였다. $1^{\circ}Bx$의 황금홍삼 추출물은 총페놀과 총플라보노이드 함량이 각각 212.2 mg GAE와 3.5 mg CE였다. ABTS, DPPH 및 ORAC 법으로 측정시, 황금홍삼 추출물의 산화방지능은 각각 272.3, 141.2, $868.4mg\;VCE/^{\circ}Bx$였다. 황금홍삼 추출물은 과산화수소로부터 유래한 세포 내 산화스트레스를 감소시켜 PC-12 신경세포의 생존율을 농도 의존적으로 증가시켰다. 또한, 황금홍삼 추출물은 신경전달물질인 아세틸콜린을 가수분해하는 AChE 및 BChE 활성을 억제하였다. 이러한 결과는 금 나노입자를 처리한 홍삼을 이용한 산화방지 및 신경손상억제 소재로 활용할 가능성을 제시하였다.

• 산업식품공학
• /
• 제23권4호
• /
• pp.290-296
• /
• 2019

우리나라에서 쌀(Rice, Orzya sativa L.)은 주식일 뿐만 아니라 다양한 가공식품원료로서 그의 가치가 높은 식품자원이다. 본 연구는 쌀맥주 제조 시 당화가 잘되는 쌀의 전처리 방법에 대해 탐색하고자 수행되었다. 쌀을 미세분쇄, 수침처리, 볶음처리, 호화처리, 팽화처리 후 맥아와 함께 당화를 한 결과, 팽화미를 함유한 맥즙이 가장 높은 당도(°Bx)를 나타내었다. 또한 액화 및 당화효소를 첨가하지 않고, 맥즙을 제조 시 쌀 30% 첨가했을 때 당도가 가장 높은 결과를 나타내었다. 볶은쌀과 팽화미를 이용하여 10, 20, 30% 첨가한 맥주를 제조한 결과 팽화미를 30% 첨가한 맥즙의 가용성고형분이 15.4 °Bx로 가장 높고 당화도 잘되었으며, 맥주의 알코올함량이 5.0-5.4%로 볶은쌀 첨가 맥주에 비해 높았으며, 탁도가 없었고 쓴맛도 적은 결과를 보였다. 팽화처리는 쌀의 당화를 개선 할 수 있는 좋은 가공방법이라고 생각되며, 팽화미를 첨가한 쌀맥주 제조방법은 편리하고, 좋은 품질의 맥주를 생산 할 수 있는 방법 중의 하나라고 기대된다.

• 대한방사선기술학회지:방사선기술과학
• /
• 제15권1호
• /
• pp.65-78
• /
• 1992

Routine chest radiography is generally imaged by high voltage technique but some radiological technologists use low voltage for imaging. High voltage is usually said between $120\;kV{\sim}140\;kV$. Some RTs like using heavy filtration but others seldom like using it. However which is better for use calcium tungustate film screen system or ortho system and high contrast film or wide latitude c-type film for the exculusive use of chest radiography. We could not make a decision which is ideal method for use. In my opinion any method is not always exellent for chest radiography. In my experiments that I had at Kaken hospital in Japan last year I expect to keep the balance between image quality and diagnostic range and to reduce radiation dose for patients. My experiments are as follows. 1. We have looked into system characteristics(speed and contrast) in accordance with kVp($80{\sim}140$) and added filter($no{\sim}1/16\;VL$) in three screen film systems(BX3+CRONEX4, SRO750+MGH, SRO750+MGL). 2. We have looked into skin dose and film dose with same D=1.8 lung field density in accordance with kVp($80{\sim}140$) and added filter($no{\sim}1/16\;VL$) in three screen film systems. 3. We have compared with the evaluation between correlation of physical image quality(MTF) and optical diagnostic capability. Result are follows. 1. Speed of BX3+CRONEX4 became higher in accodance with kVp and thickness of filter but speed of ortho system was not as like regular system. Thicker filter diminished the speed over 100 kV range in SRO750+MGL. In case of SRO750+MGH speed of 1/16VL filter was looked into lower than speed of 1/4VL filter. Sensitivity of ortho system depends on tube voltage and added filter. 2. Skin dose has been detected $225\;{\mu}Gy{\sim}66\;{\mu}Gy$ in BX3+CRONEX4 from 80 kV, no filter to 140 kV, 1/16VL filter. SRO750+MGH could reduce the patient dose $1/2{\sim}1/3$ level in comparison to that of BX3+CRONEX4. 3. The higher kV was the worse MTF became the thicker filter was the worse MTF became too. MTF of BX3+CRONEX4 was detected better than MTF of SRO750+MGH but SRO750+MGH's optical detectability of small lesion in lung field came out better than that of BX3+CRONEX4. Conclusion Recently routine chest radiography is generally imaged by high voltage but it seems to be there are some questions in using of film screen combination. In high voltage chest radiography the subject contrast will come down that means latitude become wider. In this case if we select the low contrast film screen system(C or L type) the film contrast will fall down extremly and detectability of small lesion will be deteriorated. Wide latitude C, L type film has a merit of high detectability on mediastinum. Furthermore high contrast film screen system has the advantage to keep the high contrast in low density region as like mediastinum and heart shadow. Therefore in low subject contrast high voltage chest radiography we would rather choose the high contrast film screen system(H type) I think. From a view point of patient dose detectability of mediastinum and lung field. The optimum technical facter was found out 120 kV, 1/16VL filter : BX3+CRONEX4, 140 kV, 1/4VL filter : SRO750+MGH, 100 kV, 1/4VL filter : SRO750+MGL.

• 정보과학회지
• /
• 제33권6호
• /
• pp.17-22
• /
• 2015