• 대한화학회지
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• 제26권2호
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• pp.88-94
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• 1982

요소공장의 굴뚝에서 방출되는 가스상 암모니아와 입자상 암모늄을 측정하여 대기중에서 암모니아가 암모늄으로 전환되는 속도를 추정하였다. 암모니아가 암모늄으로 전환되는 것은 대기중에서의 수송시간에 따라 2단계로 나누어진다. 수송 초기 15분동안의 전환속도는 3.2%ㅡmin$^{-1}$이고 그 후는 0.26%min$^{-1}$이었다. 수송 초기단계에서 전환속도가 빠른 것은 굴뚝에서 방출된 유출가스의 온도강하에 의하여 생성된 물방울에 암모니아가 용해하고, 또 이 알칼리성 물방울에서 요소가 분해반응을 일으킴으로써 암모늄의 농도가 급격히 증가하였기 때문인 것으로 추정되었다. 암모니아 가스의 반감기는 수송 초기단계에서 약 16분이고, 그 후는 192분이었다. 측정기간에 있어서 입자상 암모늄염과 대기온도, 상대습도, 이산화황, 질소산화물 및 부유분진 농도와의 사이에는 상관관계가 관찰되지 않았다.

• Applied Microscopy
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• 제26권1호
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• pp.17-31
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• 1996

검은과부거미의 독 분비장치는 두흉부에 있는 가위턱과 한쌍의 독선으로 이루어져 있다. 독선은 한겹의 얇은 장막과 횡문근 섬유의 다발에 의해 둘러싸여 있었고. 근육층을 따라서 운동신경의 축삭 돌기와 근섬유 사이에 신경근육간 연접이 형성되어 있었다. 분비상피를 이루는 단층 원주상피세포에는 복잡한 수지상의 돌기가 형성되었고, 독선 전체가 단포상선을 이루고 있음이 관찰되었다. 상피의 분비면은 기저막으로부터 선의 내강쪽으로 확장된 세포질 돌기에 의해 표면적이 현저히 증가되었고, 상피의 내강면에는 조밀한 미세융모가 형성되어 있었다. 독성 분비물은 상피세포 내에서 두 종류의 분비과립으로부터 생성되었다. 분비기동안 이들 분비과립은 과적의 형태로 변형, 농축된 후, 이출분비의 형태로 내강으로 방출되었다. 방출 후의 기저부 상피세포들은 고도의 증식과정을 거쳐 원주상의 상피세포로 재생됨이 확인되었다.

• 한국임상수의학회지
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• 제30권2호
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• pp.100-106
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• 2013

A clinical trial was performed to assess clinical efficacy and/or reduction in relapses by gold-bead implantation into acupuncture points in dogs with canine chronic recurrent otitis externa (CCROE). Forty dog-patients randomly divided into two groups were diagnosed as suffering CCROE, having intact tympanic membranes and a history of recurrences. Treatments were: control group (CG), treated with commercially available antimicrobial otic droplets, dosed twice daily for 7 days; and experimental group (GBI- gold bead implants), treated as for CG plus the insertion of 13 gold-bead implants under light anesthesia. Overall per cent assessment of composite clinical progression and progression of individual clinical signs were recorded. Bilateral chronic external otitis was diagnosed in 60% of the cases and left or right otitis in 20% of the cases each. Logistic model for repeated measures analysis showed that GBI induced a better clinical recovery as far as lesion score of some clinical signs is concerned. The overall percent cures of each group showed statistically significant difference. A McNemar analysis revealed that higher number of relapses was observed in CG patients as compared to the GBI (P < 0.05). In particular during these days, lesion on the pinna showed in odd ratios analysis a 7:1 ratio (recurrence CG:GBI) and ear wax/pus (4:1) from D42 to D365. It is concluded that gold-bead implantation into acupuncture points improves resolution of some clinical signs and greatly reduce relapses in CCROE affected dogs after 1 year follow-up (98.75%).

• 대한기계학회논문집A
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• 제29권1호
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• pp.67-73
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• 2005

The paper presents a single-heater microfluid injector, whose ejected droplet volume is adjusted by digital current path control for a single microheater. The previous droplet volume adjustable methods have used the digital current control for multiple heaters or the analog current control for a single heater, while the present method uses the digital current control for a single microheater. Two different microinjectors, having a rectangular heater and a circular hearter, are designed and fabricated in the chip area of $7.64\;mm{\times}5.26\;mm$. The fabricated microinjectors have been tested and characterized for the number, size, shape and lifetime of the generated bubbles as well as for the volume and velocity of the ejected droplets. The input power for the rectangular heater and the circular heater has been varied in the ranges of $8.7{\sim}24.9{\mu}W\;and\;8.1{\sim}43.8{\mu}W$, respectively. The projected area of the generated bubble has been changed in the ranges of $440{\sim}l,3600{\mu}m^2\;and\;800{\sim}3,300{\mu}m^2$ for the rectangular heater and the circular heater, respectively. The microinjector with the rectangular heater ejects three discrete levels of the droplet in the volume range of $9.4{\sim}20.7pl$ with the velocity range of $0.8{\sim}1.7m/s$, while the microinjector with the circular heater achieves five discrete levels of the droplet in the volume range of $7.4{\sim}27.4pl$ with the velocity range of $0.5{\sim}2.8m/s$.

• 한국자원식물학회지
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• 제31권6호
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• pp.675-683
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• 2018

This study describes an efficient and widely applicable droplet-vitrification following cryopreservation for shoot tips of Chrysanthemum morifolium (Ramat.) cvs. 'Borami' and 'Yes morning'. The shoot tips of Chrysanthemum were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.7 M). Precultured explants were treated with loading solution (LS, C6) containing glycerol 20% and sucrose 20% for 30 min and exposed to dehydration solution (B5) containing 40% of glycerol and 40% of sucrose for 60 min at $25^{\circ}C$, and then transferred onto droplets containing $2.5{\mu}l$ PVS3 on sterilized aluminum foils ($4cm{\times}0.5cm$) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regeneration rate (%) was obtained when shoot tips were precultured with treatment-2 (exposing of shoot tips to MS + 0.3M sucrose for 30 h and then treated with MS+0.5 M sucrose for 16 h) at $25^{\circ}C$ in both the cultivars. The viability of cooled samples, followed by culturing on $NH_4NO_3$-free MS medium for first 5 days was increased to two-fold (80.7%) regrowth rate over those cultured on normal MS medium or MS medium containing plant growth regulators. This result shows droplet-vitrification would be a promising method for cryobanking chrysanthemum germplasm.

• Tribology and Lubricants
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• 제37권2호
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• pp.71-76
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• 2021

As opposed to using fossil fuels, we need to use eco-friendly resources such as sunlight, raindrops and wind to produce electricity and combat environmental pollution. A triboelectric nanogenerator (TENG) is a device that converts mechanical energy into electricity by inducing repetitive contact and separation of two dissimilar materials. During the contact and separation processes, electron flow occurs owing to a change in electric potential of the contacting surface caused by contact electrification and electrostatic induction mechanisms. A solid-solid contact TENG is widely known, but it is possible to generate electricity via liquid-solid contact. Therefore, by designing a hydrophobic TENG, we can gather electricity from raindrop energy in a feasible manner. To fabricate the superhydrophobic surface of TENGs, we employ a dip coating technique to synthesize an octadecylamine (ODA)- and polydimethylsiloxane (PDMS)-based coating on polyethylene terephthalate (PET). The synthesized coating exhibits superhydrophobicity with a contact angle greater than 150° and generates a current of 2.2 ㎂/L while water droplets fall onto it continuously. Hence, we prepare a box-type TENG, with the ODA/PDMS coating deposited on the inside, and place a 1.5 mL water droplet into it. Resultantly, we confirm that the induced vibration causes continuous impacts between the ODA/PDMS coating and the water, generating approximately 100 pA for each impact.

• Mycobiology
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• 제48권6호
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• pp.450-463
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• 2020

The strains 17E-042, 17E-039, and NC13-171 belong to Ascomycota and were isolated from soil collected from Sancheong-gun and Yeongam-gun, Korea. The strain 17E-042 produced white mycelial colonies that developed a sienna color with a round margin on potato dextrose agar (PDA), and the reverse side developed a light sienna color. Morphologically, this strain was similar to the strains of Arthrinium phragmites and A. hydei, but the shorter conidial size of the newly identified strain (17E-042) was distinct. The strain 17E-039 produced macroconidia that were pale yellow to orange-brown, elongated-ellipsoid to oblong, round at both ends, primarily straight but sometimes slightly curved, 0-septate, thin-walled, and filled with numerous droplets, having diameters of 20.4-34.3 × 8.0-12.0 ㎛. And the strain NC13-171 formed hyaline to light brown chlamydospores, solitary or in a chain. Multigene phylogenetic analyses were conducted using sequence data obtained from internal transcribed spacer (ITS) regions, 28S rDNA large subunit (LSU), β-tubulin (TUB2), translation elongation factor 1-alpha (TEF1-α), and RNA polymerase II large subunit (RPB2) genes. The results of molecular phylogeny, the detailed descriptions and illustrations of each species strongly support our proposal that these strains from soil in Korea be designated as Arthrinium minutisporum sp. nov. and two new records of Pezicula neosporulosa and Acrocalymma pterocarpi.

• 대한본초학회지
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• 제37권5호
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• pp.17-26
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• 2022

Objective : The aim of the present study is to examine hepatic lipid-lowering and anti-inflammatory effects of silymarin combined with Jakyakgamcho-tang on non-alcoholic fatty liver disease in a high fat diet-induced obese mice model. Methods : C57BL/6 mice were divided into four dietary groups: (1) Normal, (2) Control (60% high-fat diet), (3) Control + silymarin 50 mg/kg/day (Silymarin), (4) Control + Silymarin 50 mg/kg/day + Jakyakgamcho-tang 100 mg/kg/day (SPG). After 12 weeks administration, mice were sacrificed and lipids and inflammation-related biomarkers were analyzed liver and plasma. Results : Silymarin and SPG treatments significantly lowered body and liver weights compared to the Control. Serumlipids (triglyceride (TG), total cholesterol) and pro-inflammatory cytokines (tumor necrosis factor alpha, interleukin 1𝛽, and IL-6) concentrations were significantly lowered in the Silymarin and SPG groups than the Control group. Silymarin and SPG treatments suppressed hepatic TG level and hepatic lipid droplets compared to the Control. Theses two treatments significantly increased hepatic kinase B1 and AMP-activated protein kinase protein levels, and significantly decreased hepatic key lipogenic enzymes (acetyl-CoA carboxylase, fatty acid synthase and stearyl coenzyme A desaturase 1) protein levels than the Control. SPG also significantly increased hepatic fatty acid oxidation-related protein (peroxisome proliferator-activated receptor alpha and uncoupling protein 2) levels than the Control. Conclusions: Silymarin and SPG suppressed hepatic lipid accumulation by regulating hepatic protein expression, and lowered blood pro-inflammatory cytokines concentrations though the synergic effect of silymarin and Jakyakgamchotang was not clear.

• Advances in nano research
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• 제16권6호
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• pp.593-600
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• 2024

The nanoemulgel was prepared to induce a synergistic effect along with higher efficacy. Nine sets of macroemulsion were made in which liquid paraffin was stabilized by the two non-ionic surfactants, Tween® 80 and Span® 80. Comparative stability analysis of the macroemulsions was used to determine the effective surfactant concentrations that gave the most stable systems (NE 2, NE3, NE4, NE5). High-speed homogenization was then applied. The final formulation was evaluated for globule size and polydispersablity index, physical properties (color, homogeneity, consistency, syneresis), pH, viscosity, spreadability with 200 g and 500 g weight, conductivity, drug content, stability, skin irritation, antifungal efficacy. Zeta size analysis confirmed the nanosize of the droplets in NE2 (284.8 nm), NE3 (79.89 nm), NE4 (194 nm) but not NE5 (632.8 nm), which was outside the nanoemulsion range. The antifungal assay exhibited zone of inhibition for NE3 (43±1.0 mm) and NE4 (42±1.7 mm), a marketed cream (33±1 mm), fluconazole alone (35±1 mm) and terbinafine alone (35.0±1.7 mm). The zone of inhibition of nanoemulgels increased compared with the drugs when used individually and when compared a placebo.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권6호
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• pp.1478-1499
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• 2024

Coronavirus disease (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. COVID-19 become an active epidemic disease due to its spread around the globe. The main causes of the spread are through interaction and transmission of the droplets through coughing and sneezing. The spread can be minimized by isolating the susceptible patients. However, it necessitates remote monitoring to check the breathing issues of the patient remotely to minimize the interactions for spread minimization. Thus, in this article, we offer a wearable-IoTs-centered framework for remote monitoring and recognition of the breathing pattern and abnormal breath detection for timely providing the proper oxygen level required. We propose wearable sensors accelerometer and gyroscope-based breathing time-series data acquisition, temporal features extraction, and machine learning algorithms for pattern detection and abnormality identification. The sensors provide the data through Bluetooth and receive it at the server for further processing and recognition. We collect the six breathing patterns from the twenty subjects and each pattern is recorded for about five minutes. We match prediction accuracies of all machine learning models under study (i.e. Random forest, Gradient boosting tree, Decision tree, and K-nearest neighbor. Our results show that normal breathing and Bradypnea are the most correctly recognized breathing patterns. However, in some cases, algorithm recognizes kussmaul well also. Collectively, the classification outcomes of Random Forest and Gradient Boost Trees are better than the other two algorithms.