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  • M. L. GHOSH
    Journal of Physics of the Earth
    1972年 20 巻 2 号 165-186
    発行日: 1972年
    公開日: 2009/04/30
    ジャーナル フリー
    The possibility of attenuation of microseismic waves due to the presence of an upward folding of the ocean bottom into the liquid is discussed in this paper. The upward folding of the ocean bottom has been idealized by means of an irregularity in the form of a rectangle intruding into the liquid and the evaluation of the displacement component at any point of the solid medium has been carried out in two stages. First, the change in the incident mode of the surface wave due to the presence of the rectangular irregularity has been determined, and second, the subsequent change of the resulting displacement components due to the termination of the liquid layer and the step change in elevation of the solid medium at the continental margin has been discovered. Finally, numerical calculation has been made to determine the attenuation of the microseismic waves of different periods due to the presence of the rectangular irregularity at the ocean bottom.
  • Misaki Kojima, Takeya Morozumi
    Journal of Health Science
    2004年 50 巻 5 号 518-529
    発行日: 2004年
    公開日: 2004/10/01
    ジャーナル フリー
    Six full-length cDNAs encoding pig cytochrome P450 (CYP) enzymes, CYP1A1, CYP2A19, CYP2
    B
    22
    , CYP2C33v
    4
    , CYP2C49, and CYP2
    E
    1, were isolated and sequenced. The cDNA sequences of pig CYP1A1, CYP2A19, CYP2
    B
    22
    , CYP2C49, and CYP2
    E
    1 showed high similarity to human CYP1A1 (85.
    4
    %), CYP2A13 (
    88
    .6%),
    CYP2B6
    (
    81
    .1%), CYP2C18 (85.
    3
    %), and
    CYP2E1
    (
    82
    .5%), respectively, and pig
    CYP2C33v4
    cDNA showed high similarity to rat CYP2C23 (79.2%). Reverse transcription-polymerase chain reaction (RT-PCR) assays revealed hepatic gene expression of all these pig CYP enzymes: the order of expression was
    CYP2C33v4
    and
    CYP2E1
    > CYP2C49 > CYP1A1 and CYP2A19 >
    CYP2B22
    . In the kidney, the
    CYP2C33v4
    gene was expressed at the same level as in the liver, but the CYP1A1, CYP2A19, and
    CYP2B22
    genes were expressed at lower levels than in the liver. Little renal gene expression of CYP2C49 and CYP2
    E
    1 was observed. We revealed for the first time the full-length cDNA sequences encoding pig CYP1A1 and five CYP enzymes belonging to the CYP2 gene family, thus making it possible to examine the gene expression levels of these CYP enzymes in pig tissues by RT-PCR.
  • 増大する資源
    E
    . F. Boswell
    紙パ技協誌
    1998年 52 巻 7 号 885-889
    発行日: 1998/07/01
    公開日: 2009/11/19
    ジャーナル フリー
    The world is in the midst of a huge fundamental shift in fibre supply, demand balances, and policy changes. Governments around the world are introducing policy changes which influence the supply demand balance as the politicians' thoughts are uttered. Government agencies and their bureaucrats are imposing changes on industry even before the legislation is passed by the government in question.
    This
    ad
    hoc change process will continue for a time to come until the countries in question show a tough-mindedness with regard to their land use policies. Policies affecting forest areas such as protection areas, Native land claims, the protection of biodiversity and a true goal of sustainable development ; which addresses the combined issues of cultural, environmental, social and economic matters.
    Eventually all of these difficult issues will reach essential closure. Then there will be great new opportunities for investment to meet the growing demand for forest products ; leading to a strengthening competitive position in the more traditional producing areas such as Canada.
  • George W. Lee
    燃料協会誌
    1973年 52 巻 3 号 171-177
    発行日: 1973/03/20
    公開日: 2010/06/28
    ジャーナル フリー
  • Cbesseredes HORTS
    Journal of Human Ergology
    1982年 11 巻 Supplement 号 429-440
    発行日: 1982/12/15
    公開日: 2011/02/23
    ジャーナル フリー
  • 布施川 雄一, 多田 博己, 小熊 利明, 椎名 豊, 玉地 寛光, 半田 俊之介
    動脈硬化
    1996年 23 巻 9 号 545-551
    発行日: 1996/04/10
    公開日: 2011/09/21
    ジャーナル フリー
    The association between apolipoprotein
    E
    (Apo-
    E
    ) polymorphism and the response of plasma cholesterol to dietary therapy (cholesterol intake of less than 300mg/day) was investigated for about
    8
    weeks in 208 nonfamilial hypercholesterolemia patients (
    E
    3
    /
    3
    161,
    E
    4
    /
    3
    47). The baseline lipoprotein concentration and the intake of energy and lipids were not significantly different between subjects with
    E
    3
    /
    3
    and those with
    E
    4
    /
    3
    phenotypes. After the dietary therapy plasma total cholesterol and low density lipoprotein cholesterol were significantly decreased in both phenotype groups (p<
    0
    .05). The patients with
    E
    4
    /
    3
    had significantly smaller reductions of LDL-C than the patients with
    E
    3
    /
    3
    . The changes of LDL-C showed a significant difference between the patients with
    E
    3
    /
    3
    and
    E
    4
    /
    3
    by the Kruskal Wallis test (p=
    0
    .041). The presence of
    E
    4
    /
    3
    predicted the degree of cholesterol reduction following dietary therapy.
  • CHINGCHUAN HUANG, LILING HONG
    地盤工学会論文報告集
    2000年 40 巻 5 号 65-73
    発行日: 2000/10/15
    公開日: 2008/02/29
    ジャーナル フリー
    The applicability of a method for predicting 'bearing capacity increase'in reinforced sandy ground was examined using tests performed under various test conditions. It was found that the present method predicted, with reasonable accuracy, the bearing capacity increase in sandy ground, reinforced with stiff reinforcement. This method may not be applicable for sandy ground reinforced with extensible reinforcement due to the unsuccessful formation of a semirigid zone under the footing. An investigation into the settlement of a footing on reinforced sandy ground, at ultimate footing load condition, suggested that the settlement of footing for reaching peak footing load may be correlated to the 'deep-footing'and the 'wide-slab'mechanisms. That is, the ultimate settlement ratio between reinforced and unreinforced model sandy ground, SRf, may be linearly correlated to 'BCRD'and 'BCRs', which represent 'deep-footing' and 'wide-slab'effects, respectively, on the ultimate bearing capacity increase in reinforced sandy ground.
  • R. I.・Ittrich-Fluorometry
    田中 啓幹
    日本泌尿器科學會雑誌
    1969年 60 巻 12 号 1125-1142
    発行日: 1969年
    公開日: 2010/07/23
    ジャーナル フリー
    Urinary estrogens have been assayed chiefly with the Kober hydroquinone colorimetry or sulfuric acid fluorimetry. However, it is difficult to determine accurately small amounts of estrogens such as in urines from males, oophorectomized women or menopausal women. In this study, male urinary estrogens were determined by a modification of the method reported by Kambegawa and some experimental studies were made on male urines. 200ml aliquot of 24-hour urine is hydrolyzed by the
    3
    -step hydrolysis, added with estrone-6, 73H, 17β-estradiol-6, 73H and estriol-6, 73H, and extracted with ether, followed by alkaline washes, methylation by a supersonic wave mixer, thin layer and column chromatography, liquid scintillation spectrometry and the Ittrich fluorometry. Results of experimental studies and estimation of urinary estrogens in males are as follows: 1) After the
    3
    -step hydrolysis, 54.5% of the urinary estrogens were collected as the glucuronide, 30% in the solvolyzed fraction and 15.5% as the hot acid hydrolyzate. 2) The methylation of estrogens was achieved 10-20% better by the use of the supersonic wave mixer than by a magnetic stirrer.
    3
    ) Calculating efficiency of the Packard Tri-carb liquid scintillation spectrometer was tested in varieties of the estrogen concentrations using the dilution and the external standardization methods. There was noted no influence of the estrogen concentrations on the counting efficiency in the determination ranges.
    4
    ) In the range of 2×10-
    3
    -
    1.0μg
    , a linear relationship on the standard curve was obtained applying the Allen's correction, when fluorometry was conditioned with the excitation light wave length of 510mμ and the fluorescence wave lengths of 530, 550 and 570mμ for each of the three estrogen-methyl ethers. 5) Urinary estrogens were determined in 15 normal males. In 5 subjects (2-13 years old) the values were:
    E1
    : 1.06±1.09;
    E2
    :
    0
    .64±
    0
    .54;
    E3
    :
    0
    .76±
    0
    .68 and the total
    E
    : 2.46±1.99μg/24hr. In 5 men (
    22
    -38 years old),
    E1
    : 5.02±1.57;
    E2
    : 2.58±
    0
    .21;
    E3
    :
    4
    .11±1.
    82
    and the total
    E
    : 11.72±
    2.97μg
    /24hr. In 5 men (46-72 years old),
    E1
    :
    3
    .
    81
    ±
    0
    .31;
    E1
    : 1.71±
    0
    .48;
    E3
    :
    3
    .51±
    0
    .
    94
    and the total
    E
    : 9.03±1.33μg/24hr. 6) Urinary estrogens were also determined in patients with a variety of clinical syndromes.
  • Daria Kurguzova, Svetlana Serebrova, Alexey Prokofiev, Ludmila Krasnykh, Galina Vasilenko, Marina Zhuravleva, Elena Smolyarchuk, Anton Barkov
    日本薬理学会年会要旨集
    2018年 WCP2018 巻 WCP2018_PO3-5-27
    発行日: 2018年
    公開日: 2020/09/10
    会議録・要旨集 オープンアクセス

    Background

    The differences in conditions of enteric-coated acid-labile drug release and absorption between healthy subjects in bioequivalence studies and gastrointestinal patients in clinical practice can lead to significant differences in gastric stability of original PPIs and generics. Thus, pathologic duodenogastric reflux (PDGR) and the pH increasing within PPIs administration still remain unaccounted for.

    Methods

    Two-stage modified comparative dissolution testing of original omeprazole (OO) and four generics (G1;2;

    3
    ;
    4
    ) was performed. At first, we moved drugs from solution with pH 1.2 (1.2±
    0
    .05) to pH
    7
    .
    0
    (
    7
    .
    0
    ±
    0
    .05) and measure concentration of omeprazole in solution by high-performance liquid chromatography. According to our self-developed formula, pH
    7
    exposure time of resistance to PDGR for omeprazole is
    4
    minutes, i.
    e
    . the active substance should not be released within
    4
    minutes at pH
    7
    . The exposure at the second stage was conducted with pH
    4
    (
    4
    .
    0
    ±
    0
    .05), that imitated gastric pH after PPI administration. And then we also moved drugs to pH
    7
    with the subsequent measurement of omeprazole concentration.

    Results

    Omeprazole concentrations after

    4
    , 10, 15, 20, 30, 45, 60 minutes in pH
    7
    solution at the first stage were different for OO and generics. For OO, these values were
    4
    ,
    7
    ±
    0
    ,
    7
    %; 41,
    4
    ±
    3
    ,
    0
    %; 62,
    8
    ±
    4
    ,
    0
    %; 79,5±2,9%; 83,5±2,9%;
    81
    ,6±2,9%;
    80
    ,6±
    4
    ,
    4
    %; for Generic1 -
    0
    ; 49,
    3
    ±9,9%;
    88
    ,
    8
    ±2,
    8
    %; 90,
    4
    ±
    3
    ,
    7
    %;
    88
    , 2±2,2%; 87,
    3
    ±2,
    0
    %; 85,9±1,1%; for Generic2 -
    0
    ; 30,6±6,
    3
    %; 66,
    7
    ±
    8
    ,2%; 76,
    4
    ±
    7
    ,
    4
    %;
    82
    ,
    8
    ±5,
    3
    %; 86,
    0
    ±
    3
    ,
    7
    %; 84,6±
    3
    ,
    3
    %: for Generic
    3
    -
    80
    ,
    8
    ±
    3
    ,6%; 83,5±1,9%; 83,
    8
    ±
    3
    ,2%; 83,
    3
    ±2,
    7
    %;
    81
    ,9±2,1%;
    82
    ,1±2,
    0
    %;
    82
    ,
    0
    ±2,
    4
    %; for Generic
    4
    -
    82
    ,5±1,
    7
    %; 84,
    4
    ±
    0
    ,
    8
    %; 84,2±1,2%;
    82
    , 9±
    0
    ,9%;
    82
    ,9±
    0
    ,9%;
    82
    ,9±
    0
    ,9%;
    82
    ,
    8
    ±1,1%, respectively.

    An analysis of the omeprazole concentration in pH

    7
    solution at the second stage revealed the following parameters after the same time: for OO -
    4
    ,
    4
    ±
    0
    ,6%; 40, 5±
    3
    ,
    0
    %; 62,
    8
    ±2,
    0
    %;
    80
    ,
    0
    ±
    3
    ,1%; 85,
    4
    ±2,9%;
    82
    ,
    8
    ±
    3
    ,
    4
    %;
    80
    ,9±
    3
    ,5%; for Generic1 -
    0
    ; 67,
    0
    ±
    7
    ,
    8
    %; 89,
    7
    ±2,
    3
    %; 91, 9±
    4
    ,
    3
    %; 89,1±1,6%;
    88
    ,
    3
    ±1,
    4
    %; 87,
    8
    ±1,2%; for Generic2 -
    0
    ; 42,2±5,6%; 75,1±
    7
    ,
    3
    %;
    81
    ,
    0
    ±6,
    0
    %;
    88
    ,
    4
    ±
    3
    ,2%;
    88
    , 6±1,
    3
    %; 87,9±1,
    0
    %; for Generic
    4
    - 85,5±
    0
    ,5%; 85,6±
    0
    ,5%; 84,
    7
    ±
    0
    ,9%;
    82
    ,
    7
    ±
    3
    ,
    0
    %; 84,
    4
    ±
    0
    ,
    3
    %; 84,
    4
    ±
    0
    ,
    3
    %; 84,
    3
    ±
    0
    ,
    4
    %, respectively. Generic
    3
    release and degradation were completely realized at pH
    4
    .

    Conclusion

    Decreased gastric stability of Generic

    3
    and Generic
    4
    makes PDGR and inhibited gastric acid secretion due to PPIs administration the potential causes of decreased enteric-coated acid-labile drugs stability.

  • 川又 紀彦, 渡部 良平
    臨床血液
    2019年 60 巻 7 号 767-772
    発行日: 2019年
    公開日: 2019/08/06
    ジャーナル 認証あり

    BCR-ABL1 International Scale(IS)測定はチロシンキナーゼ阻害剤で治療されている慢性骨髄性白血病(CML)患者の治療効果をモニターする上で重要な検査法である。稀ではあるが,BCR-ABL1 IS測定ができないCMLが存在することが知られている。本研究において,我々は,そのようなBCR-ABL1 IS測定のできないCML患者を経験し,分子生物学的な方法で,その原因を解明した。本例ではABL1遺伝子における切断点がa2エクソン内にあることが分かり,そのことがABL1のa2エクソンを欠いた

    e
    14a
    3
    b
    3
    a
    3
    )キメラ遺伝子のmRNAのみの発現を誘導していた。a2エクソンは本邦における検査部でのIS測定において重要な要素であり,これが欠損することが測定不能の原因であった。このようなIS測定ができない稀なCML症例をさらに集積して,その分子構造を解明することが待たれる。

  • Grover Loening
    日本航空学会誌
    1963年 11 巻 119 号 373-380
    発行日: 1963年
    公開日: 2009/05/25
    ジャーナル フリー
  • Keishi Hata, Fuyuki Sugawara, Naganori Ohisa, Saori Takahashi, Kazuyuki Hori
    Biological and Pharmaceutical Bulletin
    2002年 25 巻 8 号 1040-1044
    発行日: 2002年
    公開日: 2002/08/01
    ジャーナル フリー
    We screened the differentiation-inducing activities of 39 mushroom extracts from Akita prefecture, Japan, on the mouse osteoblastic cell line, MC
    3
    T
    3
    -
    E
    1. Sixteen phosphate buffered saline (PBS),
    8
    boiled PBS, 14 ethanol and 12 methanol extracts induced alkaline phosphatase (ALP) activities, an indicator of MC
    3
    T
    3
    -
    E
    1 cell differentiation. The enzyme activities were markedly induced by extracts of Tricholoma auratum, and we isolated the active compound from methanol extracts of this mushroom. Physical data for the isolated active compound were identical to those for (
    22E
    ,24R)-ergosta-
    7
    ,
    22
    -diene-
    ,5α,6β-triol (1). 1 induced ALP activities of MC
    3
    T
    3
    -
    E
    1 cells and promoted cell proliferation. To investigate the relationships between the chemical structure and differentiation-inducing activity of the compound, ALP-inducing activities of MC
    3
    T
    3
    -
    E
    1 cells by 1, ergosterol (2), ergocalciferol (
    3
    ), cholesta-
    ,5α,6β-triol (
    4
    ),
    7
    -dehydrocholesterol (5) and cholecalciferol (6) were tested. The enzyme activities of MC
    3
    T
    3
    -
    E
    1 cells were increased
    3
    .
    0
    -fold by 10 μM 1 and 2.
    4
    -fold by 10 μM
    4
    . However, 2,
    3
    , 5 and 6 did not induce MC
    3
    T
    3
    -
    E
    1 cell ALP activity at
    0
    .1—10 μM. These results suggested that the OH groups at C-5 and/or C-6 of 1 and
    4
    played an important role in their differentiation-inducing activities on MC
    3
    T
    3
    -
    E
    1 cells. Furthermore, 1 suppressed induction of MC
    3
    T
    3
    -
    E
    1 cell apoptosis by serum starvation.
  • 浅岡 顕, 小高 猛司
    土質工学会論文報告集
    1992年 32 巻 3 号 117-129
    発行日: 1992/09/15
    公開日: 2008/02/29
    ジャーナル フリー
    Failure problems of saturated soils are classified in the present study into the following four types : Type I : The failure of loose and/or normally consolidated soils under fully drained loading conditions. Type II : The same soils but under perfectly undrained conditions. Type III : The failure of dense and/or overconsolidated soils under fully drained conditions. Type IV : The same soils but under perfectly undrained conditions. The soil-water coupling limiting equilibrium analysis on the basis of the critical state concept is shown possible to draw a distinction between type I, II and IV problems, and the limitations of the analysis procedure happen in solving the type problem in the above. This is demonstrated experimentally, in which seepage failure experiments in laboratory with the use of a saturated silty sand are employed to make distinctions clearly between the four types of failure problems. The definite distinctions both in failure load and failure mode appeared in the four types of experiments are summarized as follows : (1) the smallest failure load in loose sand in the undrained condition, (2) the largest failure load with the largest failure region in dense sand under undrained loading, (
    3
    ) the observation of no global deformation before failure within the soil under the fully drained condition that suggests the development of very localized shear deformation in the sand. Three out of four experiments are described well by the limit analysis computation mentioned above as far as the failure load and the shape and the size of the failure region after boiling failure are concerned, and thus the type III problem is identified to be the problem that should be solved by any other means in near future.
  • 榎 明潔, 八木 則男, 矢田部 龍一, 一本 英三郎
    土質工学会論文報告集
    1991年 31 巻 2 号 1-13
    発行日: 1991/06/15
    公開日: 2008/02/29
    ジャーナル フリー
    It has been shown after mathematical and mechanical investigation that Limit Equilibrium Method (LEM) can be considered as a method to obtain the necessary condition of Slip Line Method (SLM), and that the solution can be obtained under the condition that Fs=1 and ∂Fs/∂θ=O, where Fs is the safety factor and θ is the inclination of the plane on which the safety factor is defined. Next, the generalized LEM (GLEM) is proposed, dealing with the following points : (1) Triangular or quadrangular blocks can be treated; (2) Safety factors are defined also on interblock planes; and (
    3
    ) All types of plastic problems, slope stability, bearing capacity, and earth pressure are identically formulated. Two situations regarding treatment of the moment equilibrium condition are discussed. GLEM is applied to well-known problems. The results agree well with those obtained by theoretical methods. GLEM can be used to obtain the distribution of earth pressure or bearing capacity. GLEM, Iike ordinary LEM, is very effective for the practical problems, but GLEM is more theoretical and it can result in more accurate solutions.
  • S. Datta, J. Sil, M. K. Banerjee
    ISIJ International
    1999年 39 巻 10 号 986-990
    発行日: 1999/10/15
    公開日: 2007/05/31
    ジャーナル フリー
    The effect of composition and controlled thermomechanical process parameters on the mechanical properties of HSLA steels is modelled using the Widrow-Hoff's concept of training a neural net with feed-forward topology by applying Rumelhart's back propagation type algorithm for supervised learning, using a Petri like net structure. The data used are from laboratory experiments as well as from the published literature. The results from the neural network are found to be consistent and in good agreement with the experimented results.
  • 山口 昭彦
    日本中東学会年報
    1994年 9 巻 37-65
    発行日: 1994/03/31
    公開日: 2018/03/30
    ジャーナル フリー
    L'entree en Iran des armees britannique et sovietique s'est produite en aout 1941. Elle ebranla du coup le regime de la dynastie pahlavi qui etait au pouvoir depuis 16 ans, et mena le pays vers l'instabilite politique et le chaos social. La defaite de l'arme gouvernementale, qui etait le pivot du regime de Reza Shah, reduisit considerablement le controle du gouvernement central dans le pays. Cette situation politico-sociale confuse permit le developpement de differents mouvements politiques en Iran. C'est ainsi que le 16 aout 1942 le parti clandestin Komeley Jiyanewey Kurdistan (J-K) est ne a Mehabad, une ville au nord-ouest de l' Iran. Des sa formation, ce parti a su etendre sa sphere d'activite et, en une courte periode de temps, a fini par mettre sous son influence la ville et ses alentours. A la fin de la Seconde Guerre mondiale, en ete 1945, le J-K etait devenu une organisation representant le mouvement nationaliste kurde en Iran. C'est a ce moment-la qu'un autre parti politique, le Hizbi Dimokratiki Kurdistan (HDK), fonde par Qazi Mihemed a Mehabad aussi, devait remplacer le J-K. Des le
    22
    janvier 1946, le HDK proclama l'instauration de la≪Republique de Kurdistan≫. Cependant, les troupes sovietiques qui avaient pris sous leur protection la Republique evacuerent les terres iraniennes, en mai 1946. Six mois plus tard, sous la pression militaire du gouvernement central iranien, la republique s'ecroula. Deux theories tentent d'expliquer le passage du J-K au HDK. William Eagleton Jr., par exemple, affirme dans The Kurdish Republic of 1946 que le HDK a ete cree sur le conseil des autorites sovietiques. L'ex-secretaire general du Parti Democratique du Kurdistan d'Iran, 'Ebd el-Rehman Qasimlu maintient par contre que Qazi Mihemed a etabli le nouveau parti de sa propre initiative, eu regard a la situation politique de cette epoque-la. Il considere que la passage du J-K au HDK comme etant l'evolution d'un parti nationaliste clandestin en un parti democratique. En analysant ces deux theories et en se basant sur les autobiographies des personages qui se sont engages dans cet evenement, cette etude tentera d'examiner le principe directeur et les activites du J-K et de mieux comprendre les raisons pour lesquelles le J-K devait etre remplace par le HDK. La conclusion generale portera sur les differents objectifs politiques du J-K et du HDK. Le J-K visait l'elevation du niveau culturel du peuple tout en luttant contre le tribalisme, qui etait, selon lui, le probleme majeur de≪la nation kurde≫, et cela en ecartant toute idee de revolte militaire. Le J-K a aussi exclu de son cadre les elites sociales telles que les leaders des tribus et dirigeants religieux de peur qu'ils n'excercent une influence sur les membres du parti. L'automne de 1944 fut le debut d'une nouvelle ere pour le mouvement kurde. Alors que l'espoir de l'autodetermination augmentait parmi le peuple a mesure que s'approchait la fin de la guerre, la necessite de la force militaire a commence a se faire sentir dans le J-K. C'est pour cela que s'est produite au sein du parti une tendance a compter sur l'aide militaire des sovietiques et a recourir au leadership de Qazi Mihemed, qui avait une certaine influence meme sur les leaders tribaux. Mais cette tendance etait essentiellement incompatible avec la ligne fondamentale du J-K et, graduellement, a prive ce parti de sa raison d'etre. Ainsi, le HDK se substitua au J-K en tant que≪parti democratique≫visant a rallier d'abord les elites sociales sous sa banniere, en s'appuyant sur l'autorite personnelle de Qazi Mihemed.
  • Tariq F. Alghazzawi
    Journal of Prosthodontic Research
    2017年 61 巻 3 号 305-314
    発行日: 2017年
    公開日: 2017/09/12
    ジャーナル オープンアクセス

    Purpose: The purpose of this study was to determine if the optical properties of zirconia and glass–ceramic (

    e
    .max) were affected by low-temperature degradation (aging).

    Methods: Experiment samples were fabricated with seven zirconia brands (n=10): Zenostar, Zirlux, Katana, Bruxzir, DD-BioZX2, DD-cubeX2, NexxZr; and

    e
    .max were used as a control. This resulted in a total of
    80
    samples in the experiment. The L*, a* and
    b
    * were measured for each sample, and then the optical properties including translucency parameter (TP), contrast ratio (CR), and opalescence parameter (OP) were calculated. The samples were aged (20, 40, 60,
    80
    , 100h), and the optical properties were calculated after each interval.

    Results: Most zirconia brands had lower L*, higher a*, higher

    b
    * with increased aging, which visually corresponds to darker, redder, and more yellow. Aging also increased CR, lowered TP, and lowered OP.
    e
    .max was also affected by aging but still had the highest TP (23.9±2.
    8
    ), L* (
    81
    .
    7
    ±
    3
    .
    4
    ), and lowest CR (
    0
    .41±
    0
    .05) compared to any zirconia. The Zenostar had the closest TP (24.1±
    0
    .
    4
    ), and L* (90.2±
    0
    .5) values to
    e
    .max before aging. However, after 100h of aging, the DD-cubeX2 was least effected and had the highest TP (
    22
    .2±
    0
    .6) and lowest CR (
    0
    .43±
    0
    .01) compared with other zirconia samples and highest OP (11.
    3
    ±
    0
    .2) of all ceramic samples.

    Conclusions: The optical properties of zirconia and

    e
    .max materials were affected by aging with the effects increasing with time. The magnitude of change was affected by seven brands of dental zirconia.

  • S. DATTA, M. K. BANERJEE
    ISIJ International
    2005年 45 巻 1 号 121-126
    発行日: 2005年
    公開日: 2006/01/27
    ジャーナル フリー
    An unsupervised learning technique and an associative memory have been used for encoding weights by a special type of Petri network named Petri neural net for modelling the influence of alloying elements on the final property of the high strength low alloy steel. The combined effects of alloying elements for different strengthening mechanisms is predicted when weights and threshold values are chosen on the basis of metallurgical understanding. The technique is found to be effective to create an associative memory of input-output relations in unknown data sets so that the same can be subsequently be used as a predictive tool.
  • S. Datta, M. K. Banerjee
    ISIJ International
    2004年 44 巻 5 号 846-851
    発行日: 2004/05/15
    公開日: 2007/05/31
    ジャーナル フリー
    Primarily from the point of view of improvement of yield strength due to additions of niobium, titanium and boron in HSLA steels, the experimental steels are divided into five classes. The data are then supplied for learning a Self Organising Map (Kohonen network). It is found that the network with six neurons possesses better capacity of prediction with unknown data. Another effort of clustering the steels according to its major strength contributing mechanisms is also made. But the capacity of the network to cluster unknown data is found to be rather poor and has failed to follow from the metallurgical principles. To avoid this limitation, Learning Vector Quantisation method is adopted to impart a certain amount of supervision in the learning process and it is found that the training pattern of the network attains a good convergence thereby leading to a good predictive ability.
  • M. K. Banerjee, P. S. Banerjee, S. Datta
    ISIJ International
    2001年 41 巻 3 号 257-261
    発行日: 2001/03/15
    公開日: 2007/05/31
    ジャーナル フリー
    A boron treated copper bearing HSLA steel containing austenite formers like manganese and nickel, somewhat lower in amount than that in HSLA 100 variety of steel is chosen for the study. The role of thermomechanical processing on the microstructure and mechanical properties of the above steel has been investigated. Differential scanning calorimetric study is carried out for understanding the precipitation behaviour of copper in HSLA steel under the influence of boron. The microstructure of the experimental steel is found to consist of laths of martensites and bainite. MA constituents of ribbon like morphology are observed at the lath boundaries. Higher strength properties of the steel are attributed to the presence of finely distributed precipitates of copper and microalloy carbides.
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