• Title/Summary/Keyword: pure state

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False-Positive Mycobacterium tuberculosis Detection: Ways to Prevent Cross-Contamination

  • Asgharzadeh, Mohammad;Ozma, Mahdi Asghari;Rashedi, Jalil;Poor, Behroz Mahdavi;Agharzadeh, Vahid;Vegari, Ali;Shokouhi, Behrooz;Ganbarov, Khudaverdi;Ghalehlou, Nima Najafi;Leylabadlo, Hamed Ebrahmzadeh;Kafil, Hossein Samadi
    • Tuberculosis and Respiratory Diseases
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    • v.83 no.3
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    • pp.211-217
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    • 2020
  • The gold standard method for diagnosis of tuberculosis is the isolation of Mycobacterium tuberculosis through culture, but there is a probability of cross-contamination in simultaneous cultures of samples causing false-positives. This can result in delayed treatment of the underlying disease and drug side effects. In this paper, we reviewed studies on false-positive cultures of M. tuberculosis. Rate of occurrence, effective factors, and extent of false-positives were analyzed. Ways to identify and reduce the false-positives and management of them are critical for all laboratories. In most cases, false-positive is occurring in cases with only one positive culture but negative direct smear. The three most crucial factors in this regard are inappropriate technician function, contamination of reagents, and aerosol production. Thus, to reduce false-positives, good laboratory practice, as well as use of whole-genome sequencing or genotyping of all positive culture samples with a robust, extra pure method and rapid response, are essential for minimizing the rate of false-positives. Indeed, molecular approaches and epidemiological surveillance can provide a valuable tool besides culture to identify possible false positives.

The effect of initial Pd catalyst oxidation stale on CH$_4$sensitivity of SnO$_2$thin film sensor (Pd 촉매의 부분 산화 조절을 이용한 SnO$_2$박막 센서의 CH$_4$감도 변화 연구)

  • Choi, W. K.;Cho, J.;Cho, J. S.;Song, J. H.;Jung, H. J.;Koh, S. K.
    • Journal of the Microelectronics and Packaging Society
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    • v.6 no.2
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    • pp.45-49
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    • 1999
  • A flammable gas sensor based on the $SnO_2$thin film deposited by the reactive ion assisted deposition was fabricated and ultra-thin Pd layer as catalyst was adsorbed at surface by ion beam sputtering. The initial oxidation states of Pd catalyst were controlled to investigate the role of Pd in the sensing process of inflammale gas sensor through annealing in air and vacuum respectively. The Pd catalyst existing in pure metallic state showed the sensitivity higher than that of PdO. The result might be closely related to the fact that PdO as a surface acceptor would receive electrons via Pd sub-channel from $SnO_2$, and thus which reduces the sensitivity and delay the response time.

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Structural, Dielectric and Field-Induced Strain Properties of La-Modified Bi1/2Na1/2TiO3-BaTiO3-SrZrO3 Ceramics

  • Hussain, Ali;Maqbool, Adnan;Malik, Rizwan Ahmed;Zaman, Arif;Lee, Jae Hong;Song, Tae Kwon;Lee, Jae Hyun;Kim, Won Jeong;Kim, Myong Ho
    • Korean Journal of Materials Research
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    • v.25 no.10
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    • pp.566-570
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    • 2015
  • $Bi_{0.5}Na_{0.5}TiO_3$ (BNT) based ceramics are considered potential lead-free alternatives for $Pb(Zr,Ti)O_3$(PZT) based ceramics in various applications such as sensors, actuators and transducers. However, BNT-based ceramics have lower electromechanical performance as compared with PZT based ceramics. Therefore, in this work, lead-free bulk $0.99[(Bi_{0.5}Na_{0.5})_{0.935}Ba_{0.065}]_{(1-x)}La_xTiO_3-0.01SrZO_3$ (BNBTLax-SZ, with x = 0, 0.01, 0.02) ceramics were synthesized by a conventional solid state reaction The crystal structure, dielectric response, degree of diffuseness and electric-field-induced strain properties were investigated as a function of different La concentrations. All samples were crystallized into a single phase perovskite structure. The temperature dependent dielectric response of La-modified BNBT-SZ ceramics showed lower dielectric response and improved field-induced strain response. The field induced strain increased from 0.17%_for pure BNBT-SZ to 0.38 % for 1 mol.% La-modified BNBT-SZ ceramics at an applied electric field of 6 kV/mm. These results show that La-modified BNBT-SZ ceramic system is expected to be a new candidate material for lead-free electronic devices.

Study of Shenming Theory in ${\ulcorner}$Hwang Ti Nei Ching${\lrcorner}$ (("황제내경(黃帝內經)" 신명개념(神明槪念)의 연구)

  • Kim, Goo-Hwan;Kwon, Kang-Beom;Ryu, Do-Gon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.4
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    • pp.803-814
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    • 2007
  • Shenming(神明) exists everywhere in the universe; it affects human beings to feel and contact ideal and peaceful state of Shen(神). Shenming theory(神明思想) in ${\ulcorner}$Hwang Ti Nei Ching${\lrcorner}$ (黃帝內經) was established by ancient Northeastern Asians who were trying to apply paradigm called TianRenHeYi theory(天人合-思想), unifying man and the Great Spirit(絶對精神) of the universe. Based on present, Shenming(神明) is an idea that can estimate will of Shen(神) which has a key to the future; such concept is founded by both human's mind and action that are designed to seek for the uncertain future. Very pure and devoted mind can sympathize with Shen(神) to accept Shenming(神明). Sehnming theory(神明思想) in ${\ulcorner}$Hwang Ti Nei Ching${\lrcorner}$ (黃帝內經) has a basic concept of living balanced life as a human by accepting Shenming(神明), the Spirit of Universe. Thus, it can be summarized into a phrase, 'Shenming(神明) is a process that human conjures his ultimate destiny called the Great Spirit(絶對精神) in himself.' If a man would be guided by Shenming(神明), the Spirit of Universe, he can live peacefully. Therefore, it is essential to study Shenming theory(神明思想) in ${\ulcorner}$Hwang Ti Nei Ching${\lrcorner}$ (黃帝內經) to aid present people's mental health.

A Study on ink Saving Application Method for Domestic for Eco-Friendly Printing (국내 친환경 인쇄를 위한 Ink Saving 적용 방법에 관한 연구)

  • Koo, Chul-Whoi
    • Journal of the Korean Graphic Arts Communication Society
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    • v.30 no.2
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    • pp.35-45
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    • 2012
  • Need color separation process to appear number of minimum printing plate waterway maximum printing color at printing process. This time, printing plate is separated three primary colors of C(cyan), M(magenta), Y(yellow). Appear all colors of printing such three primary colors. But, three primary color ink appears 100% dark gray that is not clean as chroma is neared color to 0 because is not pure. As well as, the ink area rate that is whole by over print amount increase of three primary is expanded. As a result, influence in secondary printablity set-off growth by inaccurate color reproduction and ink dry badness, trapping efficiency decline etc.. Apply ink saving method that is replaced as K ink in consisted dark color constituent because three primary colors are over print each other adding one more K(black) plate by method to improve these problem. Therefore, can reduce extension of the total ink area rate, and help in correct color appearance control. As well as, eco-friendly printing process attains improving printablity at the same time curtailment of printing expense by reducing requirement of total ink. Usually, there are UCR(under color removal) and GCR(gray component replacement) to ink saving application method. But, the practical use limit is insufficient state to tribe of technological investigation or field application about these method in domestic printing field. Therefore, in this research, ink saving been bringing by one method of eco-friendly printing confirmed that is applicable in usual domestic printing environment. Also, searched result getting in printablity by ink saving application.

Effect of Crystal Form on Bioavailability (결정형이 생체이용률에 미치는 영향)

  • Sohn, Young-Taek
    • Journal of Pharmaceutical Investigation
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    • v.34 no.6
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    • pp.443-452
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    • 2004
  • Habit is the description of the outer appearance of a crystal. If the environment of a growing crystal affects its external shape without changing its internal structure, a different habit results. Crystal habit and the internal structure of a drug can affect bulk and physicochemical properties, which range from flowability to chemical stability. A polymorph is a solid crystalline phase of a given compound resulting from the possibility of at least two different arrangements of the molecules of that compound in the solid state. Chemical stability and solubility changes due to polymorphism can have an impact on a drug's bioavailability and its development program. During crystallization from a solution, crystals separating may consist of a pure component or be a molecular compound. Solvates are molecular complexes that have incorporated the crystallizing solvent molecule in their lattice. When the solvent incorporated in the solvate is water, it is called a hydrate. To distinguish solvates from polymorphs, which are not molecular compounds, the term pseudopolymorph is used. Identification of possible hydrate compounds is important since their aqueous solubilities can be significantly less than their anhydrous forms. Conversion of an anhydrous compound to a hydrate within the dosage form may reduce the dissolution rate and extent of drug absorption. An amorphous solid may be treated as a supercooled liquid in which the arrangement of molecules is random. Amorphous solids lack the three-dimensional long-range order found in crystalline solids. Since amorphous forms are usually of higher thermodynamic energy than corresponding crystalline forms, solubilities as well as dissolution rates are generally greater. A study on crystal form includes characterization of (l)crystal habit, (2)polymorphism, (3)pseudopolymorphism, (4)amorphous solid.

${\alpha}-Amylase$ production of Bacillus natto IAM 1212 in the wheat bran medium (밀기울배지를 이용한 Bacillus natto ${\alpha}-Amylase$ 생산)

  • 김광;박인호;선우양일
    • KSBB Journal
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    • v.6 no.2
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    • pp.143-146
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    • 1991
  • The liquifying $\alpha-amylase$ production from B. subtilis, A. oryzae and B. natto using wheat and rice bran as low cost culture medium was investigated. Among 3 strains, B. natto showed heights productivity of $\alpha-amylase$ in the outer wheat bran medium. And the optimum culture condition is pH 6.8 and $37^{\circ}C$ for the production of $\alpha-amylase$. The $\alpha-amylase$ activity of the crude enzyme and the purified enzyme are 256 unit/ml and 10,700 unit/ml, respectivitly. The $\alpha-amylase$ from B. natto cultrtured in outer wheat bran medium was purified into nearly a pure state(98.7%). And the molecular weight of the purified $\alpha-amylase$ was 34,000.

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Development of Cr cold spray-coated fuel cladding with enhanced accident tolerance

  • Sevecek, Martin;Gurgen, Anil;Seshadri, Arunkumar;Che, Yifeng;Wagih, Malik;Phillips, Bren;Champagne, Victor;Shirvan, Koroush
    • Nuclear Engineering and Technology
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    • v.50 no.2
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    • pp.229-236
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    • 2018
  • Accident-tolerant fuels (ATFs) are currently of high interest to researchers in the nuclear industry and in governmental and international organizations. One widely studied accident-tolerant fuel concept is multilayer cladding (also known as coated cladding). This concept is based on a traditional Zr-based alloy (Zircaloy-4, M5, E110, ZIRLO etc.) serving as a substrate. Different protective materials are applied to the substrate surface by various techniques, thus enhancing the accident tolerance of the fuel. This study focuses on the results of testing of Zircaloy-4 coated with pure chromium metal using the cold spray (CS) technique. In comparison with other deposition methods, e.g., Physical vapor deposition (PVD), laser coating, or Chemical vapor deposition techniques (CVD), the CS technique is more cost efficient due to lower energy consumption and high deposition rates, making it more suitable for industry-scale production. The Cr-coated samples were tested at different conditions ($500^{\circ}C$ steam, $1200^{\circ}C$ steam, and Pressurized water reactor (PWR) pressurization test) and were precharacterized and postcharacterized by various techniques, such as scanning electron microscopy, Energy-dispersive X-ray spectroscopy (EDX), or nanoindentation; results are discussed. Results of the steady-state fuel performance simulations using the Bison code predicted the concept's feasibility. It is concluded that CS Cr coating has high potential benefits but requires further optimization and out-of-pile and in-pile testing.

Investigation of gamma radiation shielding capability of two clay materials

  • Olukotun, S.F.;Gbenu, S.T.;Ibitoye, F.I.;Oladejo, O.F.;Shittu, H.O.;Fasasi, M.K.;Balogun, F.A.
    • Nuclear Engineering and Technology
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    • v.50 no.6
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    • pp.957-962
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    • 2018
  • The gamma radiation shielding capability (GRSC) of two clay-materials (Ball clay and Kaolin)of Southwestern Nigeria ($7.49^{\circ}N$, $4.55^{\circ}E$) have been investigated by determine theoretically and experimentally the mass attenuation coefficient, ${\mu}/{\rho}(cm^2g^{-1})$ of the clay materials at photon energies of 609.31, 1120.29, 1173.20, 1238.11, 1332.50 and 1764.49 keV emitted from $^{214}Bi$ ore and $^{60}Co$ point source. The mass attenuation coefficients were theoretically evaluated using the elemental compositions of the clay-materials obtained by Particle-Induced X-ray Emission (PIXE) elemental analysis technique as input data for WinXCom software. While gamma ray transmission experiment using Hyper Pure Germanium (HPGe) spectrometer detector to experimentally determine the mass attenuation coefficients, ${\mu}/{\rho}(cm^2g^{-1})$ of the samples. The experimental results are in good agreement with the theoretical calculations of WinXCom software. Linear attenuation coefficient (${\mu}$), half value layer (HVL) and mean free path (MFP) were also evaluated using the obtained ${\mu}/{\rho}$ values for the investigated samples. The GRSC of the selected clay-materials have been compared with other studied shielding materials. The cognizance of various factors such as availability, thermo-chemical stability and water retaining ability by the clay-samples can be analyzed for efficacy of the material for their GRSC.

Solvent Resistance and Gas Permeation Property of PEI-PDMS Hollow Fiber Composite Membrane for Separation and Recovery of VOCs (VOCs의 분리 및 회수를 위한 PEI-PDMS 중공사 복합막의 내용매성 및 기체 투과 특성)

  • Kim, Se-Jong;Lee, Chung-Seop;Koh, Hyung-Chul;Ha, Seong-Yong;Nam, Sang-Yong;Rhim, Ji-Won;Choi, Whee-Moon
    • Membrane Journal
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    • v.22 no.1
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    • pp.54-61
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    • 2012
  • To separate and recover of VOCs, supporting membranes using PEI were prepared by phase separation method and it was coated with PDMS to prepare PEI-PDMS hollow composite membrane. To investigate characteristic of prepared membrane, pure gas permeability was measured using oxygen and nitrogen, the stage cut and permeance property with feed concentration were evaluated using xylene, ethyl benzene, toluene and cyclohexane. Also, to check solvent resistance on VOCs, stress-strain property of membrane with immersion time in solvent were measured by DMA. The permeance value of $O_2$ and $N_2$ showed 63 GPU and 30 GPU respectively. Permeated VOCs concentration was decreased with increasing stage cut. But, conversely, recovery efficiency that was increased with increasing stage cut. As a result of DMA test, the stress and strain were 11.93 MPa and 13.52%, respectively.