• Membrane and Water Treatment
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• 제9권5호
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• pp.293-300
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• 2018

The removal of volatile organic compounds (VOCs) from water using KOH-activated pine tree needle leaves biochar is considered a cost effective and efficient process. In this study, pine tree needle leaves were mixed with 0, 50, 100 and 200% (KOH weight/feedstock weight) of KOH, respectively. Then, the mixture was pyrolyzed at $500^{\circ}C$ for 6 hrs. The adsorption characteristics of 10 VOCs to the biochar were tested. The results indicated that the removal efficiency of the KOH activated biochar was highest in 100% KOH-biochar. The VOC removal efficiencies of 50% and 200% KOH activated biochar were similar and the 0% KOH activated biochar showed the lowest VOC removal. The FTIR results showed that increasing the amount of KOH seemed to enhance the formation of various functional groups, such as -OH, -C=C, -O. The adsorption strength of 10 VOCs to the KOH activated biochar seemed to be increasing by the increase of the solubility of VOCs. This may suggest that the adsorption is taking place in hydrophilic sites of the biochar surface. The KOH activated pine tree needle leaves biochar can be an effective sorbent for VOCs removal in water and 100% KOH mixing seemed to provide better sorption capacity.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.339-340
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• 2006

AC spark discharge voltage of SF6/CO2and SF6/N2 containing various mixed rate in volume percent (1, 5 and 10%) of SF6 in non-uniform fields are investigated. The needle to plane electrode gap spacing was 5 and 10 mm, and the gas pressure was varied within the range of 0.1~0.7 MPa. We have observed a N-characteristic typical for the electronegative gases even in gas mixtures of 1% SF6 with CO2 and N2 as buffer gases. Especially, the materials of the needle electrode affect the insulation properties of the gas mixtures drastically. On the contrary to the case of needle electrodes made by mild steel or high carbon steel, the N-characteristics are hardly perceived in the case of stainless steel needle in this experiment.

• Journal of Gastric Cancer
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• 제22권3호
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• pp.248-259
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• 2022

Purpose: To overcome the technical difficulties of single-incision laparoscopic distal gastrectomy (SILDG), needle grasper (Endo Relief^TM)-assisted SILDG (NASILDG) was developed. Here, we compared the operative convenience and postoperative outcomes between SILDG and NASILDG. Materials and Methods: A needle grasper was inserted into the right upper abdomen and used in the NASILDG. We retrospectively reviewed patients who underwent D1 + dissection and delta-shaped Billroth I anastomosis with SILDG or NASILDG performed by a single surgeon between September 2015 and August 2018. Results: The SILDG (male, 50.0%) and NASILDG (male, 60.0%) groups included 10 and 15 patients, respectively. The operative time without combined operation and anastomosis was significantly shorter in the NASILDG group. Early complications and scar characteristics were not significantly different between the two groups. Conclusions: By adding a needle grasper, SILDG became more convenient without decreasing cosmetic results. NASILDG could be a recommended method to reduce the technical difficulty of SILDG.

• 조명전기설비학회논문지
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• 제22권2호
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• pp.128-133
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• 2008

이 논문은 반구형 수조에 설치되어 있는 침전극과 구형전극에 표준뇌임펄스전압을 인가하였을 때 나타나는 수중 방전현상과 절연파괴특성을 나타낸다. 이 논문의 목적은 뇌서지에 대한 과도접지임피던스와 관련된 기본적인 특성을 파악하는데 있다. 인가전압의 극성과 물의 저항률에 따른 방전광을 촬영하였고 절연파괴전압의 의존성을 측정하였다. 침전극과 구형전극의 끝단에서 스트리머코로나가 발생하였고 접지된 수조를 향하여 단계적으로 진전하였다. 저항률에 따른 절연파괴전압은 V자 형태를 나타내며, 구형전극의 절연파괴전압-시간곡선이침전극보다 높게 나타났다.

• Preventive Nutrition and Food Science
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• 제20권2호
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• pp.148-152
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• 2015

To develop functionally and nutritionally improved whole soybean curd (WSC), the effects of partial (0~4%) replacement with pine needle powder (PNP) on the quality characteristics of WSC were investigated. The moisture content and pH ranged from 76.96~77.80% (wet basis) and 6.69~6.74, respectively, with no considerable differences. Lightness significantly decreased with higher PNP content in the formulation (P<0.05), as indicated by visual observation that the color of WSC became darker. Redness and yellowness also significantly decreased (P<0.05). The texture profile analysis indicated that WSC containing PNP was softer and less cohesive than control WSC. 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical scavenging activities significantly increased (P<0.05) with higher substitution of PNP, and they were well correlated. Results from the consumer test revealed that WSC with 1% PLP received the most favorable acceptance scores for sensory attributes, including overall acceptability. The present study indicated that the characteristics of PNP may play a role in improving WSC quality in terms of physicochemical, sensorial, and antioxidant characteristics.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.59-62
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• 1999

Inception and propagation of electrical tree and properties of Partial discharge(PD) pulses accompanying with tree as a function of needle tip radius in low density polyethylene were discussed. To study on these characteristics in different tip radius, we used specimens with needle-plane electrode system made of LDPE, observed inception and propagation of electrical tree by optical microscope with computer and investigated the characteristics of the phase resolved PD pulses accompanying with propagation of electrical tree. The PD quantities detected and analysed were PD magnitude, mean phase angle, average discharge, and the statistical characteristics of the PD pulses. As the tip radius ${\gamma}$ increases, tree inception stress E$\sub$i/ converges to constance value. This result suggests that tree inception stress E$\sub$i/ increases due to stress relaxation when the tip radius is small. Branch-type electrical tree was formed When E$\sub$i/ is 640-750[kV/mm]. bush-type electrical tree when E$\sub$i/ is 370∼400[kV/mm], branch-like electrical tree when E$\sub$i/ is 370-400[kV/mm].

• 조명전기설비학회논문지
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• 제29권11호
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• pp.74-81
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• 2015

In the measurement of atmospheric static electric field, it is important to know characteristics of corona discharges caused at the tip of test electrode. This paper presents the fundamental data of DC corona discharges that occurred at the tip of a needle-shaped electrode placed in the homogeneous background electric field which simulates the atmospheric static field under thundercloud. The major characteristics of interest for this purpose are the polarity effect of corona discharges and the magnitudes and time intervals of corona current pulses. The experimental set-up consists of the plate-to-plate configuration with a needle-shaped protrusion, DC power supply, and voltage and current measuring devices. As a result of experiments, the polarity dependence of corona pulses is significantly pronounced. The time intervals between successive corona pulses in the negative polarity is much longer than those in the positive polarity. The time intervals for both polarities is drastically decreased as the applied electric field is increased. Also the magnitudes of the positive corona pulses are slightly changed with an increase in applied electric field, but those of the negative corona pulses are linearly increased with increasing the applied electric fields.

• 전기학회논문지
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• 제57권4호
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• pp.635-640
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• 2008

New gas mixtures are now finding applications such as interrupting media for high-voltage circuit breakers. These mixtures consist of a high content of carbon tetrafluoride($CF_4$) added to sulfur hexafluoride($SF_6$). Nowdays $SF_6$ has been established for the use in gas insulated substations due to its high insulation withstand level and good arc quenching capability. At this paper Breakdown characteristics were investigated for $SF_6/CF_4$ mixtures when AC voltage and standard lightning impulse voltage(LI) was applied in a needle-plane electrodes. And partial discharge(PD) experiments were carried out in the test chamber which was made in needle-plane electrode. And ${\Phi}$-Q-N distribution of partial discharge signals was analyzed. The total pressure of the $SF_6/CF_4$ mixtures was varied within the range of 0.1-0.5 Mpa in the test chamber. The breakdown voltage in needle-plane electrode displayed N shape characteristics for increasing the content of $SF_6$ at positive impulse voltage and the PD inception voltage was increased slightly when pressure of $SF_6/CF_4$ Mixtures was increased. Maximum PD inception voltage is showed in 80% SF6/20%$CF_4$.

• Korean Journal of Acupuncture
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• 제27권2호
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• pp.71-78
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• 2010

Objectives : The warm needling technique is a combination of acupuncture and moxibustion. The purpose of this study was to find the physical and thermal characteristics in order to identify the effects and mechanisms of the warm needling technique. Methods : In this study, the thermal changes were observed with a testo 845 device, which is an infra-red thermometer specifically designed for measuring a combustion of corn shaped moxibustion(moxa-corn). The thermal changes at the apex of the moxa-corn placed on the top of the an acupuncture were observed at the level of 1 cm and 2 cm from the apex to understand heat conduction through acupuncture needle for combustion of moxa-corn. Results and Conclusions : The thermal conduction through acupuncture needle from the moxa-corn was relative to the weight of moxa-corn and was inversely relative to the distance of the moxa-corn and acupuncture needle length. And the value of thermal conduction to the apex of the acupuncture needle from the moxa-corn was about $3{\sim}5^{\circ}C$. The above results suggest that the present study may be useful in finding the mechanism and effects of the warming needling technique.

• 한국산림과학회지
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• 제76권4호
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• pp.410-417
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• 1987

제주도(濟州道)에 식재(植載)된 삼나무에 대(對)한 엽형(葉型)을 분류(分類)하고 생장특성(生長特性)을 조사(調査)함과 동시에 일본각지(日本各地)의 천연생(天然生) 삼나무와의 유사성(類似性)에 대(對)하여 비교검토(比較檢討)하였다. 제주도(濟州道) 삼나무의 엽형(葉型)은 총(總) 9개형(個型)으로 대별(大別)할 수 있으며, 각조사구(各調査區)에서 6개형(個型) 이상(以上)의 엽형출현(葉型出現)으로, 여러 계통(系統)이 혼재(混在)하고 있음을 알 수 있었다. 일본(日本)의 Ura(이(裏)) 계통(系統) 삼나무의 형태(形態)를 한 엽형(葉型), 즉 침엽각도(針葉角度) 중용이하(中庸以下), 만곡도(灣曲度), 침엽장(針葉長)이 작은 형(型)(각각(各各) $28^{\circ}$ 미만(未滿), 3.2~8.9, 7.3~12.8 mm)의 개체(個體)가 수고생장(樹高生長)에서 우세(優勢)함을 나타내었다. 이러한 개체(個體)를 지위(地位)가 좋은 곳에 조림육성(造林育成)할 경우 임지생산력(林地生産力)의 증대(增大)를 기대(期待)할 수 있다고 추찰(推察)되었다.