• 제목/요약/키워드: PNS

검색결과 262건 처리시간 0.024초

Electrical properties of the Porous polycrystalline silicon Nano-Structure as a cold cathode field emitter

  • Lee, Joo-Won;Kim, Hoon;Lee, Yun-Hi;Jang, Jin;Oh, Myung-Hwan;Ju, Byung-Kwon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.1035-1038
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    • 2002
  • The electrical properties of Porous polycrystalline silicon Nano-Structure (PNS) as a cold cathode were investigated as a function of anodizing condition, the thickness of Au film as a top electrode and the substrate temperature. Non-doped 2${\mu}m$-polycrystalline silicon was electrochemically anodized in HF: ethanol (=1:1) mixture as a function of the anodizing condition including a current density and anodizing time. After anodizing, the PNS was thermally oxidized for 1 hr at 900 $^{\circ}C$. Then, 20nm, 30nm, 45nm thickness of Au films as a top electrode were deposited by E-beam evaporator. Among the PNSs fabricated under the various kinds of anodizing conditions, the PNS anodized at a current density of 10mA/$cm^2$ for 20 sec has the lowest turn-on voltage and the highest emission current than those of others. Also, the electron emission properties were investigated as functions of measuring temperature and the different thickness of Au film as a top-electrode.

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열분해 잔유를 원료로 한 분산제의 제조 및 특성 (The Preparation and Properties of Petroleum Sulfonate Dispersant)

  • 최상원;김은영;장우석;김빅토르;문장수
    • 공업화학
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    • 제18권5호
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    • pp.490-494
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    • 2007
  • 올레핀 제조를 위한 열분해공정에서의 잔유(PPRO)를 원료로 황산화 반응을 통하여, polynaphthalene sulfonate formaldehyde condensate (PNS) 반응 공정에 비하여 좀더 단순한 공정으로 2 h 이내의 반응시간에도 우수한 성능의 무기물 분산용 분산제(NPS)를 제조 하였다. 합성한 분산제의 자외선 흡수 곡선은 PNS와 비슷하여 다양한 나프탈렌 유도체의 구조임을 알 수 있었다. NPS는 시멘트, 산화철 및 탄산칼슘 등 무기입자들의 분산계에 이용할 수 있는 우수한 성능을 나타내었다.

개인 항법 시스템을 위한 센서 위치와 보폭 추정 알고리즘 (Estimation of the Sensor Location and the Step for Personal Navigation System)

  • 김태은;이호원;좌동경;홍석교
    • 전기학회논문지
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    • 제59권11호
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    • pp.2058-2065
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    • 2010
  • This paper presents the sensor location and step estimation algorithm for personal navigation system (PNS). PNS has the disadvantage in that the position of the sensor must be fixed on a human body. Three-axis acceleration sensor is used to solve the disadvantage and to consider the real situation. We simplify the measurement data by using the band pass filter, witch It has the advantage in the detection of characteristic point. Through the detected characteristic points, it is possible to setup the parameter for the pattern detection. Depending on the sensor location, the parameters have the different type of noise covariance. Particularly, when the position of the sensor is changed, the impulse noise shows up. Considering the noise, we apply the recursive least square algorithm using the variable forgetting factors, which can classify the sensor location based on the estimated parameters. We performed the experiment for the verification of the proposed algorithm in the various environments. Through the experimental results, the effectiveness of the proposed method is verified.

부비동 단순 X선 촬영으로 확인한 소아 환자의 비염(鼻炎)과 부비동염(副鼻洞炎) 비교 (Comparison Between Rhinitis and Sinusitis in Young Patients Diagnosed by PNS Plain Radiograph)

  • 김진명;김윤범;남혜정
    • 한방안이비인후피부과학회지
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    • 제21권3호
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    • pp.140-149
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    • 2008
  • Objective : This study was performed to find out the difference of symptoms between rhinitis and sinusitis in young patients who were diagnosed by PNS plain radiograph( PNS series), Methods: We did statistical analysis about 147 new outpatients under 12 year-old who had visited the department of ophthalmology, otolaryngology, dermatology in Kyung Hee Oriental Medicine Center from March 2, 2006 to February 29, 2008. All of the patients were diagnosed by PNS series and we divided the patients with two groups; rhinitis group and sinusitis group. We checked the OPD records and explore the distribution on sex, experience of past western therapy, age and duration. Then we divided symptoms into nine; 'nasal obstruction', 'purulent rhinorrhea', 'cough & sneezing', 'watery rhinorrhea', postnasal drip', 'sputum', 'head problem', 'snoring & throat discomfort' and 'epistaxis'. We also divided age into 2 groups: $0\sim7$ years old and $8{\sim}12$ years old. We carried out chi-square test as a statistical method. Results : The results were as follows. 1. Sinusitis group were 102(69.5%); 62 have only sinusitis. 40 have both sinusitis and adenoidal hypertrophy. Rhinitis group were 45(30.5%); 13 have adenoidal hypertrophy and 32 were negative. 2. Male were 98(sinusitis 65, rhinitis 33), female were 49(sinusitis 37, rhinitis 12). 3. Patients who had experienced past western therapy were 120(sinusitis 81, rhinitis 39), no experienced patients were 27(sinusitis 21, rhinitis 6). 4. Distribution on age of sinusitis was 1(1 yr), 2(2 yrs), 3(3 yrs), 15(4 yrs), 15(5 yrs), 23(6 yrs), 13(7 yrs), 12(8 yrs), 8(9 yrs), 5(10 yrs), 1(11 yrs), 4(12 yrs). Distribution on age of rhinitis was 1(1 yr), 0(2 yrs), 1(3 yrs), 1(4 yrs), 9(5 yrs), 5(6 yrs), 3(7 yrs), 5(8 yrs), 1(9 yrs), 8(10 yrs), 6(11 yrs), 5(12 yrs), 5. Duration of sinusitis was 20(<2 months), 6($2{\sim}3$ months), 11($3\sim6$ months), 34($6\sim12$ months), 31(>12 months) and of Rhinitis was 11(<2 months), 0($2\sim3$ months), 5($3\sim6$ months), 18($6\sim12$ months), 11(>12 months) 6. Distribution on symptoms, sinusitis patients were 86(nasal obstruction), 52(purulent rhinorrhea), 46(cough & sneezing), 38(watery rhinorrhea), 41(postnasal drip), 23(sputum), 18(head problem), 15(snoring & throat discomfort), 6(epistaxis). The each symptom and sinusitis have no relation by chi-square test. 7. The number of patients who were 0 $\sim$ 7 years old was 92: sinusitis 72(49%), non-sinusitis 20(13.6%). The number of patients who were 8 $\sim$ 12 years old was 58: sinusitis 30(20.4%), non-sinusitis 25(l7%). By chi-square test(confidence level 95%), sinusitis and age under 7 have a significant relation(p=0.003). Conclusions : There is no relation between rhinologic symptoms and sinusitis. Patients under 7 years old with rhinologic symptoms tend to have sinusitis.

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폐콘크리트 미분말을 활용한 콘크리트의 감수제 함유량에 따른 강도특성(PNS계 혼화제) (Strength Characteristics of Concrete Using Superplasticizer content of Waste Concrete Powder)

  • 박신우;정의인;김봉주
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 추계 학술논문 발표대회
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    • pp.103-104
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    • 2015
  • This study is an experiment about what affects the compressive strength by using a reducing agent (PNS based admixtures) to play cement using the cement paste based Waste Concrete Powder of waste concrete, which accounts for more than 60% of construction waste around the latest domestic and international It was. Securing the replacement of cement with Waste Concrete Powder and, by varying the admixture was to compensate for the low absorption of liquidity and obtain a fine powder. And the experiment was conducted with a constant water cement ratio and aggregate usage for the purpose of lowering the water cement ratio promoting strength development. When substituted with the experimental results of 0.3% based on 3 ~ 28 days as strength 36Mpa exhibited the highest strength.

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혼화제 종류에 따른 메타카올린 콘크리트의 특성 (Properties of Metakaolin Concrete containing Various Superplasticizers)

  • 안태호;김용태;강범구;김병기
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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    • pp.539-544
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    • 2002
  • The properties of mortar and concrete including metakaolin as a partial cement replacement were investigated in terms of fluidity and compressive strength. The results show that mortar and concrete in which 10 % of cement is replaced with metakaolin exhibit much higher compressive strength after 3 days of hydration than ordinary Portland cement, indicating that metakaolin can be used in the production of high strength concrete replacing silica fume. The type of superplasticizer largely affected on the fluidity and compressive strength of mortar and concrete including metakaolin. It was concluded that when metakaolin is used for the purpose of manufacturing high strength concrete, it is desirable to use PNS based blends rather than PNS, PMS and polycarboxylate based superplasticizer.

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폴리나이트로젠 에너지물질 (Polynigrogen Energetic Materials)

  • 이준웅
    • 한국군사과학기술학회지
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    • 제19권3호
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    • pp.319-329
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    • 2016
  • Current research trends of prediction of possible structures, synthesis and explosive characteristics of polynitrogen molecules(PNs) are reviewed. Theoretically PNs are composed only of nitrogen atoms, in which N-N bonds are either single or double bonds, and thus when these molecules decompose, release of enormous energy is accompanied. From the middle of 20th century energetic material chemists have been seeking possible structures and the methods of synthesis of these new materials. As a results, from $N_4$ to $N_{60}$ together with their ions are predicted, and experimental chemists have been trying to synthesize these materials with a few success, including the famous ${N_5}^+$ ion in 1999. Although experimental successes are very rare beyond $N_5$ until today, the author believes that renovative ideas together with sincere efforts will bring someday next generation of high energy materials such as nitrogen fullerene($N_{60}$) in reality.