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Journal articles on the topic 'Constante optique'

Author: Grafiati

Published: 4 June 2021

Last updated: 17 February 2022

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1

Guinet, M., C. Daussy, S. Briaudeau, A. Amy-Klein, Y. Hermier, Ch J. Bordé, and C. Chardonnet. "Premiers résultats de mesure optique de la constante de Boltzmann par métrologie des fréquences." Journal de Physique IV (Proceedings) 135, no. 1 (October 2006): 181–82. http://dx.doi.org/10.1051/jp4:2006135048.

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2

Quintas Ripoll, Valentín. "Diseño óptimo de pórticos formados por perfiles laminados rectos de sección constante." Informes de la Construcción 39, no. 392 (December 30, 1987): 53–64. http://dx.doi.org/10.3989/ic.1987.v39.i392.1615.

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3

Hissel, J., and P. Salengros. "Nouveau mode de représentation graphique de l'équilibre calco-carbonique Application au traitement des eaux." Revue des sciences de l'eau 15, no. 2 (April 12, 2005): 435–58. http://dx.doi.org/10.7202/705464ar.

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Cet article traite des problèmes liés à l'étude des équilibres calco-carboniques en limitant leur présentation à l'aspect purement graphique. Dans cette optique, on a développé un nouvel abaque original en choisissant comme coordonnées pH et [CO3 total]. La construction d'un tel abaque ne fait appel qu'à 2 lois fondamentales, à savoir : a) la relation du produit de solubilité du carbonate calcique : Ks=Y22[Ca2+[CO2-3] Cette dernière peut, moyenant l'introduction d'une variable auxiliaire : ∆=[Ca2+]-[CO3 total] se transformer en une relation équivalente plus commode pour le calcul des courbes constitutives de l'abaque. b) une deuxième relation, prenant en compte les ions H+ soit libres, soit engagés dans des combinaisons avec le groupe carbonate ou avec le solvant H2 O. Dans ce but, on introduit une concentration totale appelée acidité potentielle totale (en abrégé APT) définie de la sorte : APT=2[H2CO3]+[HCO-3]+[H2O]+[H+] En outre, on utilise une variable dérivée de APT à laquelle on a donné le nom d'acidité potentielle carbonatée et le symbole. Sa définition est la suivante : δ=2[H2CO3]+[HCO-3] Les 2 variables et APT jouissent en commun de la propriété intéressante de rester invariantes lors de la mise en équilibre de l'eau selon l'équation : CaCO3+H+⇌Ca2++HCO-3 La variable peut également être considérée comme pratiquement invariante dans le domaine des eaux naturelles. Cette propriété est mise à profit pour construire 2 réseaux de courbes constitutives de l'abaque, à savoir : a) celles satisfaisant à la condition : APT=constante. Ces dernières seront appelées "courbes d'iso-acidité b) celles répondant à la condition : ∆=constante. On les désignera sous le nom de "courbes d'iso-équilibre" L'article s'attache à décrire le mode d'utilisation de cet abaque tout en mettant en valeur sa facilité d'emploi pour l'évaluation, tant qualitative que quantitative du comportement d'une eau à l'égard du carbonate calcique. En particulier, la technique permet de visualiser les caractéristiques essentielles de l'eau telles que pH équilibrant, pH stabilisant et indice de stabilisation, caractéristiques dont la signification est précisée dans l'article. L'abaque en question, en parallèle avec un logiciel qui peut lui être associé, constitue ainsi un outil précieux tant pour caractériser une eau que pour procéder ensuite aux traitements chimiques les plus connus. Le cas du mélange d'eaux peut également être avantageusement traité par le biais de cet abaque. De nombreux exemples d'application aux traitements de l'eau sont également largement développés dans la publication. Ceux-ci devraient aider grandement ceux qui sont confrontés aux divers problèmes de l'industrie de l'eau. L'analyse graphique constitue par ailleurs une excellente introduction à la gestion informatisée plus complète de ces problèmes et dont le traitement ne pouvait trouver place dans le cadre limité de cette publication. Le lecteur désireux de poursuivre ces développements ou d'avoir accès au programme informatique complémentaire à cette étude, trouvera les indications nécessaires dans les références bibliographiques figurant en fin de l'article.

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4

ROYER, D., and V. KMETIK. "MESURE OPTIQUE DE CONSTANTES PIÉZOÉLECTRIQUES À L'AIDE D'UNE SONDE INTERFÉROMÉTRIQUE HÉTÉRODYNE." Le Journal de Physique IV 02, no. C1 (April 1992): C1–785—C1–788. http://dx.doi.org/10.1051/jp4:19921171.

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5

Guang-Bin Yang. "Optimum constant-stress accelerated life-test plans." IEEE Transactions on Reliability 43, no. 4 (1994): 575–81. http://dx.doi.org/10.1109/24.370223.

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6

Liu, Chao, Yuan Fang Qu, Feng Long Han, Yuan Liang Li, and Xiao Yan Li. "Dielectric Properties of (Bi_1/2Na_1/2)TiO₃-SrTiO₃ Ferroelectric Ceramics." Key Engineering Materials 336-338 (April 2007): 49–50. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.49.

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Ferroelectric properties of (Bi1/2Na1/2) TiO3-SrTiO3 were studied. The dielectric properties were measured at 1KHz. It was found that the dielectric constants are improved with the increase of additive amount of BNT. If the amount continues increasing, the properties become worse, the optimum dielectric constant of the samples can reach 4300. When the proportion of (Bi1/2Na1/2)TiO3: SrTiO3 is 65:35, with the increase of additive amount of MnCO3, the Curie temperature descends obviously. The dielectric constant increased at beginning and dropped sharply when the amount of MnCO3 exceeds 1.1wt%.

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7

Mouchart, J., G. Lagier, and B. Pointu. "Détermination des constantes optiques n et k de materiaux faiblement absorbants." Applied Optics 24, no. 12 (June 15, 1985): 1808. http://dx.doi.org/10.1364/ao.24.001808.

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8

Sakurai, K., T. Hanawa, N. Kikuchi, K. Nishio, K. Tonooka, R. Wang, H. Bando, and H. Takashima. "Epitaxial Growth of (Na,K)NbO3 Films by Pulsed Laser Deposition." MRS Proceedings 1494 (2013): 227–32. http://dx.doi.org/10.1557/opl.2013.410.

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ABSTRACT(Na,K)NbO3 is a promising candidate for lead-free piezoelectric materials. (Na1-xKx)NbO3 films (x = 0.3–0.7) were epitaxially grown on a (100)SrTiO3 substrate via pulsed laser deposition. The effects of substrate temperature and oxygen pressure during deposition on the crystallinity of the films were examined: both parameters affected the mosaic spread of the crystallites and the formation of an impurity phase. In this study, the optimum conditions for the preparation of highly crystalline films were a substrate temperature of 800 °C and oxygen pressure of ∼60 Pa. The lattice constants parallel and perpendicular to the substrate surface responded differently to changes in x: the constant parallel to the surface increased with increasing x, while the constant perpendicular to the surface was maximized at x = 0.5. The difference in the dependence of the lattice constants could be explained by the elastic distortion of the lattice.

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9

Suzuki, Kenta, Yutaka Arimitsu, Yuji Sogabe, and Zhiqiang Wu. "Optimum topologies of micropolar materials depending on elastic constants." Proceedings of The Computational Mechanics Conference 2017.30 (2017): 066. http://dx.doi.org/10.1299/jsmecmd.2017.30.066.

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10

Coelho, Alan Anthony. "Optimum Levenberg–Marquardt constant determination for nonlinear least-squares." Journal of Applied Crystallography 51, no. 2 (March 20, 2018): 428–35. http://dx.doi.org/10.1107/s1600576718001784.

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A new method for determining an approximate optimum value for the Levenberg–Marquardt constant has been shown to improve the convergence rate of nonlinear least-squares problems including complex X-ray powder diffraction and single-crystal structural refinements. In the Gauss–Newton method of nonlinear least squares, a lower value for the objective function is occasionally not realized after solving the matrix equationAΔp=b. This situation occurs when either the objective function is at a minimum or theAmatrix is ill conditioned. Invariably the Levenberg–Marquardt method is used, where the matrix equation is reformulated to (A+ λI)Δp=band λ is the Levenberg–Marquardt constant. The values chosen for λ depend on whether the objective function increases or decreases. This paper describes a new method for setting the Levenberg–Marquardt constant, as implemented in the computer programTOPAS-AcademicVersion 7, which in general results in an increased rate of convergence and additionally a lowering of the objective function as a function of starting parameter values. The reduction in computation is problem dependent and ranges from 10% for typical crystallographic refinements to 50% for large refinements. In addition, the method can be applied to general functions including cases where the objective function comprises both the sum of squares and penalties including functions with discontinuities. Of significance is the trivial extra computational effort required in determining λ as well as the simplicity in carrying out the calculation; the latter should allow for easy implementation in refinement programs.

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11

Camacho-Velazquez, Rodolfo, Fernando Rodriguez, Agustin Galindo-Nava, and Michael Prats. "Optimum Position for Wells Producing at Constant Wellbore Pressure." SPE Journal 1, no. 02 (June 1, 1996): 155–68. http://dx.doi.org/10.2118/28715-pa.

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12

Racheva, Petya Vassileva, Kiril Blazhev Gavazov, Vanya Dimitrova Lekova, and Atanas Nikolov Dimitrov. "Complex Formation in a Liquid-Liquid Extraction System Containing Cobalt(II), 4-(2-Pyridylazo)resorcinol, and Nitron." Journal of Materials 2013 (March 21, 2013): 1–7. http://dx.doi.org/10.1155/2013/897343.

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Complex formation and liquid-liquid extraction were studied in a system containing cobalt(II), 4-(2-pyridylazo)resorcinol (PAR), 1,4-diphenyl-3-(phenylamino)-1H-1,2,4-triazole (Nitron, Nt), water, and chloroform. The effect of some experimental parameters (pH, shaking time, concentration of PAR, and concentration of Nt) was systematically investigated, and the optimum conditions for cobalt extraction as an ion-association complex, (NtH+)[Co3+(PAR)2], were found. The following key equilibrium constants were calculated: constant of association (Log β=4.77±0.06), constant of distribution (LogKD=1.34±0.01), and constant of extraction (LogKex=6.11±0.07). Beer’s law was obeyed for Co concentrations up to 1.7 μg mL−1 with a molar absorptivity of 6.0×104 L mol−1 cm−1 at λmax=520 nm. Some additional characteristics, such as limit of detection, limit of quantification, and Sandell’s sensitivity, were estimated as well.

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13

Logofatu, P. C., D. Apostol, V. Damian, and R. Tumbar. "Optimum angles for determining the optical constants from reflectivity measurements." Measurement Science and Technology 7, no. 1 (January 1, 1996): 52–57. http://dx.doi.org/10.1088/0957-0233/7/1/007.

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14

Blum, Rick S., and Saleem A. Kassam. "Optimum distributed constant false alarm rate detection of weak signals." Journal of the Acoustical Society of America 98, no. 1 (July 1995): 221–29. http://dx.doi.org/10.1121/1.413759.

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15

Jevtić, D. B. "Optimum Disjoint Constant-Weight Codebooks for Multiple-Access OR Channels." SIAM Review 34, no. 3 (September 1992): 497–98. http://dx.doi.org/10.1137/1034093.

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16

Kristanto, Yosua Hendra, Welina Ratnayanti Kawitana, and Tri Anggono Prijo. "Arm Cycle Ergometer Electro-Mechanical System Design For Post-Stroke Medical Rehabilitation." Indonesian Applied Physics Letters 2, no. 1 (July 14, 2021): 10. http://dx.doi.org/10.20473/iapl.v2i1.28298.

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This study was done to make the electro-mechanical arm ergometer cycle system used as post-stroke patient physiotherapy. The management system was expected to set the rotary frequency according to the therapeutic needs. To set the frequency of the rotation, the PID control with rotation sensor was used as feedback. The rotating sensor used consisted of the optocoupler and a rotary encoder. Based on the research that has been done, obtained constants of Kp = 0055, Ki and Kd = 2545 = 0.00005. Constants were selected because they were the most optimum constant trial and error method. The system is made to have a more significant percentage of error of 5%. In this study, the response time values obtained for each additional mass of the load at each frequency setting result are increased.

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17

de Oliveira, L. L. A., and M. V. Travaglia. "Optimizing the spring constants of forced, damped and circular spring-mass systems—characterization of the discrete and periodic bi-Laplacian operator." IMA Journal of Applied Mathematics 86, no. 4 (July 26, 2021): 785–807. http://dx.doi.org/10.1093/imamat/hxab021.

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Abstract We optimize the spring constants $k^{i,j}$ (stiffness) of circular spring-mass systems with nearest-neighbour (NN) and next-nearest-neighbour (NNN) springs only. In this optimization problem, such systems are also subjected to damping and periodic external forces. The function to be minimized is the average ratio of the square norm of the on-site internal forces (response) to the square norm of the external on-site forces (input). Under the average of this response/input ratio is meant the average over time and over all configurations of external forces. As main result, it is established that the optimum stiffness matrix converges to the discrete and periodic bi-Laplacian operator as the size $n$ of the system increases. Such a result is obtained under the following assumptions: (a) the system has the natural mode shape (eigenvector) of alternating $1$s and $-1$s; and (b) the (external) forcing frequency is at least $1.095$ times higher than the highest natural frequency. It is remarkable that this optimum stiffness matrix exhibits negative stiffness for the springs linking NNN point masses. More specifically, as $n$ increases, $0> k^{i,i+2} \, \, = \, \, - \tfrac{1}{4} \, k^{i,i+1}$ is the relation between the optimum NNN spring constant and the optimum NN spring constant. Such systems illustrate that the introduction of negative stiffness springs in some specific positions does in fact reduce the average response/input ratio. Numerical tables illustrating the main result are given.

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18

HIRAYAMA, Daisuke, Mutsuhiro FUZITA, and Makoto NAKATSUGAWA. "The Identification Method of Optimum Radar Constants by Using Dischrge Information." PROCEEDINGS OF HYDRAULIC ENGINEERING 39 (1995): 261–66. http://dx.doi.org/10.2208/prohe.39.261.

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19

Byoungjo Choi and L. Hanzo. "Optimum mode-switching-assisted constant-power single- and multicarrier adaptive modulation." IEEE Transactions on Vehicular Technology 52, no. 3 (May 2003): 536–60. http://dx.doi.org/10.1109/tvt.2003.810970.

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20

Martin, Hector, Fey Mohammed, Kevin Lal, and Shannon Ramoutar. "Maintenance strategy selection for optimum efficiency – application of AHP constant sum." Facilities 38, no. 5/6 (December 16, 2019): 421–44. http://dx.doi.org/10.1108/f-05-2018-0060.

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Purpose There are limited studies addressing how choosing a maintenance strategy can contribute towards maximising outputs from given inputs, thereby minimising costs and improving a company’s competitiveness. The analytic hierarchy constant sum method (AHCSM) is used to access the appropriateness of maintenance strategies for improving the overall efficiency of a structural steel fabrication construction company. Design/methodology/approach A semi-structured interview was formulated with the stakeholders of the quality department to understand the company’s maintenance portfolio and its current functional capability. The information from this case study was then dissected to represent the factors that the company deemed appropriate for evaluating their maintenance strategy. The AHCSM approach provided a framework, which ranked the importance of factors that are sensitive to the construction industry and rank the suitability of maintenance strategies. Findings Factors affecting the selection of maintenance strategies to improve business efficiency are productivity, quality, reliability, cost, safety and work environment, morale, inventory and flexibility. Total productive maintenance strategy produces the most desirable outcome; however, the predictive or condition-based maintenance strategy provides an optimum solution for the case study company while considering the equipment usage, frequency of production and the current economic climate. Originality/value The approach presented allows practitioners to consider ways to increase the level of production and improve the efficiency of construction businesses without a high increase in investment. The findings can inform gaps in existing maintenance approaches in achieving business objectives.

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21

MIYATA, Kenichi, Jiro ODA, Yoichiro KOIKE, Yojiro ISHINO, and Norio OHIWA. "311 An Optimum Configuration of Fan-Stirred Constant Volume Premixed Combustor." Proceedings of Autumn Conference of Tohoku Branch 2008.44 (2008): 95–96. http://dx.doi.org/10.1299/jsmetohoku.2008.44.95.

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22

Dellimore, Kiran H. J., Garth Cloete, and Cornie Scheffer. "Towards optimum chest compression performance during constant peak displacement cardiopulmonary resuscitation." Medical & Biological Engineering & Computing 49, no. 9 (July 23, 2011): 1057–65. http://dx.doi.org/10.1007/s11517-011-0812-5.

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23

Khazieva, Regina, and Maksim Ivanov. "Selection of the optimum device parameters for constant magnetic field generation." E3S Web of Conferences 288 (2021): 01004. http://dx.doi.org/10.1051/e3sconf/202128801004.

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The aim of the work is to develop a device design for creating constant magnetic fields and select its parameters, select an electrical circuit for powering the device and determine how the energy efficiency of the device changes with an increase in its overall dimensions. When solving the problem, the KOMPAS-3D three-dimensional modeling system was used, the magnetic field induction was calculated using the Pascal ABC programming system, the optimal device parameters were selected using the Microsoft Excel program. Calculations have shown that the coefficient taking into account the inhomogeneous distribution of the magnetic field in the device is 0.883. The optimum ratio between the height and the radius of the cylinder, along which the emulsion flows, is h = r √ 20 hr. Using the KOMPAS-3D three-dimensional modeling system, a model of the device under development was built taking into account the obtained relationships. When using a circuit with an uncontrolled rectifier and autotransformer, the power consumed by the device is 2.67 times lower than the power consumed by the device when using a circuit with a controlled rectifier and a transformer. Energy efficiency increases significantly with the increase in device performance.

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24

Saeed, Muhammad Mufazzal, Munir Ahmed, and Abdul Ghaffar. "Adsorption Behaviour of Hg(II) from Acetate Medium onto PAR-Imbedded Polyurethane Foam." Adsorption Science & Technology 21, no. 1 (February 2003): 67–80. http://dx.doi.org/10.1260/02636170360699822.

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The sorption behaviour of a 2.46 • 10−5 M solution of Hg(II) on 4-(2-pyridylazo)resorcinol (PAR)-loaded polyurethane foam (PUF) was investigated. Optimum sorption was observed from acetate medium at pH 6 with the maximum equilibration time being 30 min. The kinetic data indicated an intraparticle diffusion process with sorption being first order. The rate constant k was 0.053 min−1. The classical Freundlich and Langmuir adsorption isotherms were tested. The Freundlich constants 1/n and Kf were determined as 0.40 and 1.07 • 10−3 mol/g, respectively, and the Langmuir constants ‘M’ and ‘b’ were 3.84 • 10−5 mol/g and 3.5 • 104 dm3/mol, respectively. A sorption free energy (E) of 12.9 kJ/mol indicated chemisorption. The numerical values of the thermodynamic parameters ΔH, ΔS and ΔG indicated that sorption was spontaneous and exothermic in nature. The Scatchard equation was tested as a means of evaluating the binding sites of PUF with Hg(II). The stability constants for sorption were determined and the sorption mechanism was discussed.

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Vaupel, Thomas, and Claudius Löcker. "Design of leaky-wave antennas with transverse slots for end-fire radiation with optimized radiation efficiency." Advances in Radio Science 17 (September 19, 2019): 71–75. http://dx.doi.org/10.5194/ars-17-71-2019.

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Abstract. A substrate integrated waveguide (SIW) with transverse slots on the top plane can be used to design an effective leaky-wave antenna with good frequency beam-scanning and platform integration capability. For a main beam near end-fire, the phase constant of the radiating wave must be near to the free space wavenumber or slightly larger. In this context, the modified Hansen-Woodyard condition gives an optimum phase constant to maximize the directivity at end-fire. For the analysis of the wave propagation we have implemented a modal analysis for rectangular waveguides with transverse slots. Near end-fire, three types of modal solutions exists, a leaky improper mode, a surface wave mode and a proper waveguide mode. The leaky mode can reach phase constants larger than the free space wavenumber to fulfill the Hansen-Woodyard condition, but loses strongly its physical significance in this slow wave region, thus the excitation of the leaky-wave becomes negligible there, whereas the proper waveguide mode is dominant but exhibits only a negligible radiation loss leading to a strong drop of the antenna efficiency. Therefore, the optimum efficiency of 86 % for maximizing the gain as proposed in the literature cannot be reached with this kind of leaky wave antenna. But it will be shown in this contribution by analyzing antenna structures with finite aperture lengths, that the efficiency can reach nearly 100 % if the phase constant of the leaky-wave meets exactly the free space wavenumber (ordinary end-fire condition) and the aperture length is adjusted with regard to the attenuation constant of the leaky-wave from the modal analysis. For a given aperture length, a procedure is outlined to adjust the attenuation constant in several steps at the desired ordinary end-fire frequency to reach maximum gain and efficiency.

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26

Rajamohan, N., and M. Rajasimman. "Parametric, equilibrium and kinetic studies on the removal of mercury using ion exchange resin." Water Practice and Technology 12, no. 2 (June 1, 2017): 305–13. http://dx.doi.org/10.2166/wpt.2017.037.

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This experimental research was an investigation into removal of mercury by using a strong acid cation resin, 001 × 7. Parametric experiments were conducted to determine the optimum pH, resin dosage, agitation speed and the effect of change in concentration in the range of 50–200 mg/L. High resin dosages favoured better removal efficiency but resulted in lower uptakes. Equilibrium experiments were performed and fitted to Langmuir and Freundlich isotherm models. Langmuir model suited well to this study confirming the homogeneity of the resin surface. The Langmuir constants were estimated as qmax = 110.619 mg/g and KL = 0.070 L/g at 308 K. Kinetic experiments were modeled using Pseudo second order model and higher values of R2 (>0.97) were obtained. The Pseudo second order kinetic constants, namely, equilibrium uptake (qe) and rate constant (k2), were evaluated as 59.17 mg/g and 40.2 × 10−4 g mg−1 min−1 at an initial mercury concentration of 100 mg/L and temperature of 308 K.

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27

Montazerozohori, M., S. Nezami, and S. Mojahedi. "Kinetic Study of Photocatalytic Degradation of Tolonium Chloride Under High Pressure Irradiation in Aquatic Buffer Systems." E-Journal of Chemistry 8, s1 (2011): S19—S26. http://dx.doi.org/10.1155/2011/961843.

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Anatase titanium dioxide catalyzed photodegradation of tolonium chloride at various bufferic pH of 2, 7, 9 and 12 in aqueous solution is presented. The effect of some physicochemical parameters such as initial concentration of dye, catalyst amount and reaction time on photocatalytic degradation has been investigated in a photo-reactor cell containing high pressure mercury lamp to obtain the optimum conditions in each bufferic pH at constant temperature. A complete spectrophotometric kinetic study of tolonium chloride under high pressure irradiation at buffer media was performed. The photocatalytic degradation observed rate constants (kobs) were found to be 2.90×10-3, 3.30×10-3, 3.20×10-3and 5.20×10-3min-1for buffer pH of 2-12 respectively. It was found that a pseudo-first-order kinetic model based on Langmuir-Hinshelwood one is usable to photodegradation of this compound at all considered buffer pH. In addition to these, the Langmuir-Hinshelwood rate constants, krfor the titled compound at various pH are reported.

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28

Jensen, Frank. "The optimum contraction of basis sets for calculating spin–spin coupling constants." Theoretical Chemistry Accounts 126, no. 5-6 (November 28, 2009): 371–82. http://dx.doi.org/10.1007/s00214-009-0699-5.

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29

Dat, Nguyen Tien. "The optimum of wave forces acting on axisymmetric, paraboloidal bodies." Vietnam Journal of Mechanics 19, no. 3 (September 30, 1997): 19–24. http://dx.doi.org/10.15625/0866-7136/10056.

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In this paper, wave forces acting on axisymmetric paraboloidal bodies are considered by using numerical model presented in [1]. The optimum of wave forces is obtained in the case of constant Volume and constant wetted surface of the bodies.

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30

Yamauchi, Jun, and Yasuo Deguchi. "1H and 14N ENDOR spectra of tert-butylphenylnitroxide." Canadian Journal of Chemistry 66, no. 8 (August 1, 1988): 1862–66. http://dx.doi.org/10.1139/v88-301.

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1H and 14N ENDOR spectra of tert-butylphenylnitroxide were observed in ethylbenzene solution. The experimental conditions for detecting optimum 1H and 14N ENDOR lines were quite different. The 1H hyperfine coupling constants and their signs are discussed from the viewpoints of molecular orbital calculations, general triple resonance, CRISP (cross relaxation intensity sequence pattern) method, and steric hindrance. In view of the large anisotropic hyperfine interaction between the nitrogen and the unpaired electron, detection of 14N ENDOR in nitroxide radicals is rather difficult, so that a TM110 mode cavity was utilized in this experiment. The observed 14N hyperfine coupling constant 11.86 G at −80 °C is one of the smallest values observed to date for nitroxide radicals.

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31

Kusumoto, Mitsuru, Yuichi Yoshida, and Hiro Ito. "Constant-Time Approximation Algorithms for the Optimum Branching Problem on Sparse Graphs." International Journal of Networking and Computing 3, no. 2 (2013): 205–16. http://dx.doi.org/10.15803/ijnc.3.2_205.

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32

HU, ZHONG-KUN, JUN LUO, and WEN-MIN WANG. "OPTIMUM CONFIGURATION OF DETERMINING THE GRAVITATIONAL CONSTANT G WITH FOUR ATTRACTING MASSES." International Journal of Modern Physics D 11, no. 06 (July 2002): 913–20. http://dx.doi.org/10.1142/s0218271802002104.

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A configuration with four attracting masses in the determination of Newtonian gravitational constant G by the time-of-swing method is proposed. One couple of attracting masses is put in the outer space of the two attracted masses and another couple one is put in the inner space. Because the signals of the two couples of attracted masses will be superposed while the noises due to the uncertainty of the attracted masses separation will be compensated. There exists an optimum separation between the attracted masses, in which the requirement of measuring this separation can be reduced by a factor of about 400.

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33

Shaw, A., and A. Alexopoulos. "Optimum number of faces for phased array radar in constant dwell surveillance." Electronics Letters 41, no. 3 (2005): 154. http://dx.doi.org/10.1049/el:20057139.

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34

Ghiasi, Hossein, Damiano Pasini, and Larry Lessard. "Optimum stacking sequence design of composite materials Part I: Constant stiffness design." Composite Structures 90, no. 1 (September 2009): 1–11. http://dx.doi.org/10.1016/j.compstruct.2009.01.006.

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Damircheli, Mehrnoosh, and Babak Eslami. "Design of V-shaped cantilevers for enhanced multifrequency AFM measurements." Beilstein Journal of Nanotechnology 11 (October 6, 2020): 1525–41. http://dx.doi.org/10.3762/bjnano.11.135.

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As the application of atomic force microscopy (AFM) in soft matter characterization has expanded, the use of different types of cantilevers for these studies have also increased. One of the most common types of cantilevers used in soft matter imaging is V-shaped cantilevers due to their low normal spring constant. These types of cantilevers are also suitable for nanomanipulation due to their high lateral spring constants. The combination of low normal spring constant and high lateral spring constants makes V-shaped cantilevers promising candidates for imaging soft matter. Although these cantilevers are widely used in the field, there are no studies on the static and dynamic behavior of V-shaped cantilevers in multifrequency AFM due to their complex geometry. In this work, the static and dynamic properties of V-shaped cantilevers are studied while investigating their performance in multifrequency AFM (specifically bimodal AFM). By modeling the cantilevers based on Timoshenko beam theory, the geometrical dimensions such as length, base width, leg width and thickness are studied. By finding the static properties (mass, spring constants) and dynamic properties (resonance frequencies and quality factors) for different geometrical dimensions, the optimum V-shaped cantilever that can provide the maximum phase contrast in bimodal AFM between gold (Au) and polystyrene (PS) is found. Based on this study, it is found that as the length of the cantilever increases the 2nd eigenmode phase contrast decreases. However, the base width exhibits the opposite relationship. It is also found that the leg width does not have a monotone relationship similar to length and base width. The phase contrast increases for the range of 14 to 32 µm but decreases afterwards. The thickness of a V-shaped cantilever does not play a major role in defining the dynamics of the cantilever compared to other parameters. This work shows that in order to maximize the phase contrast, the ratio of second to first eigenmode frequencies should be minimized and be close to a whole number. Additionally, since V-shaped cantilevers are mostly used for soft matter imaging, lower frequency ratios dictate lower spring constant ratios, which can be advantageous due to lower forces applied to the surface by the tip given a sufficiently high first eigenmode frequency. Finally, two commercially available V-shaped cantilevers are theoretically and experimentally benchmarked with an optimum rectangular cantilever. Two sets of bimodal AFM experiments are carried out on Au-PS and PS-LDPE (polystyrene and low-density polyethylene) samples to verify the simulation results.

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Whalley, R., and M. Ebrahimi. "Optimum Ship Steering-Stabilization Control." Journal of Ship Research 47, no. 03 (September 1, 2003): 237–46. http://dx.doi.org/10.5957/jsr.2003.47.3.237.

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The problem of ship steering-stabilization control is outlined. A constant-speed, openwater, warship model relating the yaw and roll angle to input changes on the rudder and stabilizer fins is presented. The coupled nature of the model is demonstrated and simple open-loop precompensation is proposed. Analysis, followed by closed-loop design procedures, which induce desired dynamic characteristic s, are invoked. Optimum minimum control effort regulation is achieved via regenerative feedback. The penalty costs incurred when operating under suboptimum conditions are commented upon.

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Krishna, R. Hema, and A. V. V. S. Swamy. "Studies on Removal of Cr (VI) from Aqueous Solutions Using Powder of Mosambi Fruit Peelings (PMFP) As a Low Cost Sorbent." E-Journal of Chemistry 9, no. 3 (2012): 1389–99. http://dx.doi.org/10.1155/2012/769674.

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The powder of mosambi fruit peelings (PMFP) was used as an adsorbent for the removal of heavy metal like Cr (VI) from aqueous solutions was studied using batch tests. The influence of physico-chemical key parameters such as the initial metal ion concentration, pH, agitation time, adsorbent dosage, and the particle size of adsorbent has been considered in batch tests. Sorbent ability to adsorb Cr (VI) ions was examined and the mechanism involved in the process investigated. The optimum results were determined at an initial metal ion concentration was 10 mg/lit, pH=2, agitation time – 60 min, an adsorbent dose (150 mg/50 ml) and the particle size (0.6 mm). The % adsorption, Langmuir constants [Q0=7.51(mg/g) and b=1.69(mg/lit)] Freundlich constant(Kf=2.94), Lagergren rate constants (Kad(min-1)=5.75 x 10-2) for [Cr(VI)] 10 mg/lit were determined for the adsorption system as a function of sorbate concentration. The equilibrium data obtained were tested using Langmuir, Freundlich adsorption isotherm models, and the kinetic data obtained were fitted to pseudo first order model.

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38

Yang, Sheng Yao, and Judith Bower Carberry. "Enhancement of PCB congener biodegradation by pre-oxidation with Fenton's reagent." Water Science and Technology 30, no. 7 (October 1, 1994): 105–13. http://dx.doi.org/10.2166/wst.1994.0319.

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Polychlorinated biphenyls (PCBs) were widely used in a number of industrial applications for about 60 years and became distributed extensively in the environment due to their insolubility and persistence. Biodegradability of some PCB congeners has been confirmed by previous work, indicating degradation mechanisms involving dechlorination and cometabolism. Slow microbial conversions can be enhanced by pre-oxidation with Fenton's reagent (FR) to assist microbial decomposition of PCB congeners. In this study two model PCB congeners, 4,4′-dichlorobiphenyl (DCB) and 2,2′,4,4′,6,6′-hexachlorobiphenyl (HCB) were used as model PCBs. Bioremediation of artificially PCB-contaminated soil was measured by gas chromotography using an electron capture detector. Soil samples, both treated with FR and untreated, were subjected to constant temperature degradation tests using a selected microbial consortium for PCBs. Statistically different biodegradation rate constants were obtained for the two model PCB congeners when FR pre-oxidation was carried out at an optimum pH of 3, compared with an unpretreated comparable system. The rate constant for HCB was 5 times greater for the pretreated system, and up to 3 times greater for DCB.

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McDonald, C. K. "Germination response to temperature in tropical and subtropical pasture legumes. 1. Constant temperature." Australian Journal of Experimental Agriculture 42, no. 4 (2002): 407. http://dx.doi.org/10.1071/ea00188.

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The germination response of 13 promising and commonly used tropical and subtropical legumes in northern Australia was tested in the laboratory at 10 constant temperatures ranging from 8 to 447deg;C. Total percent germination for most species was high at temperatures from 16 to 36°C, with Macroptilium atropurpureum, Lablab purpureus and Glycine latifolia germinating well at 12°C. Macroptilium atropurpureum and G. latifolia had less seed death than other species at 8°C. There was no germination at 8 or 44°C for any species. Optimum temperature for rate of germination ranged from 24°C for G. latifolia up to 36°C for Macroptilium bracteatum. Leucaena leucocephala showed a 12-degree range (24-36°C) of optimum temperatures for rate of germination, but most species had a range of 4-8°C. The ability to germinate at a broad range of temperatures indicates that the species are well adapted to northern Australia. Consideration of these responses could be useful in selection of future species or cultivars. Existing linear models with base, optimum and ceiling temperatures, and coefficients of germination rate above and below optimum temperature were tested to predict germination from thermal time. Predicted germination in real time explained 73-90% of the variation in observed germination, with the closeness of fit poor at temperatures distant from optimum. Models using a series of step-wise linear equations describing each 5% interval of germination explained over 99% of the variation in cumulative germination with time, but required a large number of parameters.

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Esfandiari, Ramin S., James M. Sloss, Kazem M. Sadeghi, and Teh Fu Yen. "DETERMINATION OF OPTIMUM RATE CONSTANTS FOR AUTOCATALYTIC REACTION OF TAR SAND RECOVERV PROCESS." Fuel Science and Technology International 9, no. 5 (June 1991): 537–48. http://dx.doi.org/10.1080/08843759108942283.

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41

Melnikova, E. I., and E. V. Bogdanova. "Estimation of the kinetic parameters of whey proteins proteolysis in the UF-concentrate of cheese whey." Proceedings of the Voronezh State University of Engineering Technologies 82, no. 4 (January 20, 2021): 107–12. http://dx.doi.org/10.20914/2310-1202-2020-4-107-112.

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The purpose of the research is to substantiate the choice of enzyme preparations Promod 523MDP, Promod 439L, Flavorpro 766MDP, and Flavorpro 750MDP (Biocatalysts Limited, UK) and to determine the effective time of whey proteins hydrolysis in an ultrafiltration concentrate (UF-concentrate) of cheese whey for reducing their allergenicity based on the analysis of kinetic constants of the proteolysis reaction. Experimental studies were carried out with samples of cheese whey UF-concentrate with a total protein mass fraction at least 3.0% obtained with the use of industrial ultrafiltration unit MMS Swissflow UF with ceramic membranes under the conditions of the PSC Dairy Plant “Voronezhskii”. They were preliminarily subjected to enzymatic hydrolysis for 8 hours at a constant temperature, based on the dosage data, the optimum pH and the temperature of the used enzymes, recommended by the manufacturer. The specificity constant Vmax/Km was used to estimate the effectiveness of the enzyme preparations, which characterizes the constants of all stages of the hydrolysis reaction. The highest proteolysis rate has a mixture of Promod 439L and Flavorpro 766MDP in the ratio of 1.5 and 3.0%, respectively, of the total protein content in the substrate. Microscopy results showed an increasing in the solubility of nitrogen-containing components after hydrolysis due to a decreasing in hydrophobic areas on the surface of peptides. The resulting hydrolysate can be applied in the technology of a wide range of dairy products to reduce their residual antigenicity by partially replacing skim milk in the formulation.

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Yilmaz, Alper, and Tuncay Yilmaz. "Optimum Design of Cross-Flow In-Line Tube Banks at Constant Wall Temperature." Heat Transfer Engineering 37, no. 6 (September 25, 2015): 523–34. http://dx.doi.org/10.1080/01457632.2015.1060753.

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Koh, Chang Seop, Osama A. Mohammed, Jun‐o Kim, and Song‐yop Hahn. "Optimum design of voice coil motor with constant torque coefficients using evolution strategy." Journal of Applied Physics 75, no. 10 (May 15, 1994): 6045–47. http://dx.doi.org/10.1063/1.355503.

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Ismail, Ali A., Abdalla A. Abdel-Ghaly, and Eman H. El-Khodary. "Optimum constant-stress life test plans for Pareto distribution under type-I censoring." Journal of Statistical Computation and Simulation 81, no. 12 (December 2011): 1835–45. http://dx.doi.org/10.1080/00949655.2010.506440.

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Tsalides, Ph, and A. Thanailakis. "Direct computation of the array optimum tilt angle in constant-tilt photovoltaic systems." Solar Cells 14, no. 1 (April 1985): 83–94. http://dx.doi.org/10.1016/0379-6787(85)90008-0.

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46

Faqir, N. M., and I. M. Abu-Reesh. "Optimum temperature operation mode for glucose isomerase reactor operating at constant glucose conversion." Bioprocess Engineering 19, no. 1 (1998): 11. http://dx.doi.org/10.1007/s004490050476.

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47

Lyakhovich, L. S., P. A. Akimov, and B. A. Tukhfatullin. "Estimated closeness of optimum piecewise constant section width in I-rods with stability or first eigen-frequency limits to the predicted minimum material consumption with regard to strength requirements." Vestnik Tomskogo gosudarstvennogo arkhitekturno-stroitel'nogo universiteta. JOURNAL of Construction and Architecture 22, no. 4 (August 27, 2020): 114–25. http://dx.doi.org/10.31675/1607-1859-2020-22-4-114-125.

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The previous research described estimated closeness of optimum piecewise constant section width in I-rods with stability or first eigen-frequency limits to the predicted minimum material consumption with regard to strength requirements in continuous change in variable rod parameters. It is however known that in construction, rods are generally designed with piecewise constant change in the section parameters. Besides, in another work, the criterion was formulated for assessment of optimum solutions of piecewise constant sections of I-rods with stability or the first eigen-frequency limits, without considering the strength requirements. This paper focuses on a more general problem of estimated closeness of optimum piecewise constant section width in I-rods with stability or first eigen-frequency limits to the predicted minimum material consumption with regard to strength requirements.

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48

Kupren, K., A. Mamcarz, and D. Kucharczyk. "Effect of variable and constant thermal conditions on embryonic and early larval development of fish from the genus Leuciscus (Cyprinidae, Teleostei)." Czech Journal of Animal Science 56, No. 2 (February 25, 2011): 70–80. http://dx.doi.org/10.17221/312/2009-cjas.

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The aim of this study was to determine the effects of variable and constant thermal conditions on embryonic development of three endangered fish species from the genus Leuciscus. Wild living spawners of dace Leuciscus leuciscus (L.), ide L. idus (L.) and chub L. cephalus (L.) were obtained from rivers belonging to the Pasleka River basin (northeastern Poland) and next transported to a hatchery for the purpose of conducting artificial reproduction. The obtained eggs were fertilized and next incubated under a variety of thermal protocols: slow gradual heating of water (M1), rapid increase in temperature at the end of incubation (M2), fluctuating temperature (M3) and two constant temperatures (optimum and sublethal). Variable thermal changes of water were also continued after hatching, up to the yolk sac resorption by larvae. During the study it was shown that relative to incubation at optimal temperatures (12.3°C for dace, 15.7°C for ide and 19.0°C for chub), thermal modifications had no clear influence on a decrease in survival rates (differences among regimes did not exceed 5%) and increase in developmental deformations (differences below 1.0%) observed among the hatched embryos. The duration of egg incubation and developmental rate increased with increasing temperature. In the systems with modified temperature the embryonic development of dace (from fertilisation to commencement of exogenous food intake) took from 9.5 to 22.5 days, for ide from 6.1 to 12 days and for chub from 5.0 to 10.5 days. The yolk sac resorption stage in the particular species occurred from 11.7 to 23 days for dace, 7.5 to 13.2 days for ide and 5.5 to 12.8 days for chub. Different time of hatching was also reflected in the level of ontogeny of hatched embryos. Among the fish hatched at modified temperatures the largest sizes, similar to those characteristic of fish incubated at optimum temperatures, were observed in individuals originating from variants where the temperature fluctuated. The developmental disproportions among the embryos of studied species originating from different thermal regimes observed at the time of leaving the egg shells were definitely larger than during the following development stages. This study also confirmed that the embryos of studied species can adapt to increasing water temperature due to global warming up to 19.0 (dace), 23.0°C (ide) and 27.5°C (chub). The obtained results are very important not only for practical purposes but also from physiological and ecological aspects.  

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Chomchai, Wilai, and Chompoonuch Warangkanagool. "Dielectric Property of NaCu₃Ti₃NbO₁₂ Ceramics Doped with Small Amount MgO Nanopowder." Key Engineering Materials 675-676 (January 2016): 93–96. http://dx.doi.org/10.4028/www.scientific.net/kem.675-676.93.

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In this study, the NaCu3Ti3NbO12 ceramics + (0-0.5 vol%)MgO nanopowder were prepared by solid state reaction. The precursors were ball milled for 24 hours and calcined at 700-1000°C. Selected the calcinations temperature with calculate pure phase from XRD results. The powders on selected temperature were various dwell time for 2-24 hours. The optimum calcination condition for NaCu3Ti3NbO12 powder is 950°C for 24 hours. The calcined powders were doped with small amounts of MgO nanopowder and pressed into a disc shape. Sinter the green body at 975-1025°C for 10 hours. Microstructure and density were examined by scanning electron microscope (SEM) and Archimedes method with distilled water as the fluid, respectively. The rectangular grain and normal grain growth are observed. The highest relative density of NaCu3Ti3NbO12 ceramics + (0-0.5 vol%)MgO nanopowder sintered at 1000°C are close to 90%. An impedance analyzer was also used to measure the dielectric constant (εr) of 1000°C sintered sample at room temperature. The doping of small amounts of MgO nanopowder to make improved NaCu3Ti3NbO12 ceramic dielectric constants and the optimum condition for doping MgO nanopowder is 0.1 vol%.

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CLEMENTI, ANDREA, and MIRIAM DI IANNI. "OPTIMUM SCHEDULE PROBLEMS IN STORE AND FORWARD NETWORKS." International Journal of Foundations of Computer Science 06, no. 02 (June 1995): 155–68. http://dx.doi.org/10.1142/s0129054195000111.

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We investigate the problem of devising an optimal time strategy to send messages from one site to another in a Store and Forward network. We consider the problem both in the cases of messages transmitted through fixed paths and through dynamically variable paths, respectively. In particular, we prove that both of versions are NP-complete even when very restrictive hypotheses are imposed on the network topology and on the required amount of time. We thus turn our attention towards the study of the approximability of this scheduling problem. In particular, we prove the following negative results: (i) In the case of fixed paths, the problem is not approximable for any constant approximation ratio unless P is equal to NP. (ii) In the case of arbitrary paths, the problem is not approximable for any constant approximation ratio (unless P is equal to NP) when an arbitrary priority function is defined on the set of messages. Finally, we present a particular network topology in which the problem can be solved in deterministic polynomial time.

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