Metallic rough surface retrieval from the specular intensity of scattered optical waves

2000 ◽  
Vol 78 (11) ◽  
pp. 1023-1033
Author(s):  
Z D Genchev ◽  
H Y Stoyanov
Keyword(s):  
Rough Surface ◽  
Direct Determination ◽  
Single Scattering ◽  
Metallic Surface ◽  
Optical Intensity ◽  
Statistical Parameters ◽  
Optical Waves ◽  
The Mean ◽  
Analytical Expressions

We present a solution to the direct determination of the statistical parameters (root mean square deviation and correlation length), characterizing the profile of a random rough metallic surface with small slopes and heights, thus producing single scattering as well as a slight multiple scattering. This is done from the specular, coherent, component of the mean intensity of the optical waves scattered from the surface. In the frame of second-order perturbation theory, analytical expressions are derived for the specular component of the scattered radiation, and a retrieval of the rough surface parameters from the measured optical intensity is described. PACS Nos.: 02.25Fx, 03.40Kf, 41.20jb, 84.40

A Rapid Method of Determining Ammonium in Water With a Univalent Cation Glass Electrode

1971 ◽  
Vol 28 (5) ◽  
pp. 759-764 ◽  
Author(s):  
Jan Barica
Keyword(s):  
Rapid Method ◽  
Direct Determination ◽  
Glass Electrode ◽  
Ammonium Ion ◽  
Mean Error ◽  
Univalent Cation ◽  
The Mean

The use of a univalent cation glass electrode for determining ammonium in water is described. The method enables direct determination of ammonium ion in concentrations above 0.5 mg/liter without any dilution or pretreatment of sample. A constant background of Na+ and K+ in samples is required, with concentration of potassium being lower than that of ammonium. For several types of natural and enriched waters with ammonium content up to 40 mg/liter NH4-N, the mean error by the method was ±4.9%.

scholarly journals Note on the scattering of α-particles

1912 ◽  
Vol 86 (586) ◽  
pp. 235-240 ◽  
Keyword(s):  
Thin Film ◽  
Direct Determination ◽  
Single Scattering ◽  
Zinc Sulphide ◽  
Single Collision ◽  
Α Particles

In a previous paper on the scattering of the α -particles by matter the author has described experiments which allowed a direct determination of the most probable angle through which an α -particle is defected when passing through a thin film of matter.* In these experiments an intense, narrow and parallel pencil of α -particles was allowed to fall on a zinc sulphide screen, and the distribution of the scintillations over that screen was determined when tire pencil was intercepted by sheets of metal of various thickness and material. Measurements were also made for α -particles of varying speed, From this distribution the most probable defection suffered by the α -particle in each particular case was easily deduced. These deductions were based on the assumption that the scattering of the pencil is the result of a multitude of small defections suffered by the α -particles in their encounters with the atoms of the scattering foil. This type of scattering has recently been termed by Rutherford "compound scattering" in order to distinguish it from another type, denoted as "single scattering," which concerns the defections through large angles of an α -particle in a single collision. The first section of this paper deals with the distribution of the scattered α -particles on the screen; the second discusses the connection between the thickness of foils and the most probable angle of scattering which they produce. It will not be necessary to made any special assumptions as to the laws of action and reaction between the atom and the α -particle; it suffices only to suppose that the defection in each single collision is small compared with the final defection after passing through the scattering foil. This paper, therefore, does not deal with the large scattering observed by Geiger and Marsden which has been ascribed by Rutherford to single collisions. Such large defections are rare, and can be neglected in the consideration of the defections through small angles.

scholarly journals Application of ion pair complexes to design novel potentiometric membrane sensors for direct determination of frusemide in pharmaceuticals

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Nagaraju Rajendraprasad ◽  
Kanakapura Basavaiah
Keyword(s):  
Limit Of Detection ◽  
Direct Determination ◽  
Standard Addition ◽  
Ion Pair ◽  
Bromocresol Green ◽  
Bromophenol Blue ◽  
Experimental Parameters ◽  
The Mean

Abstract Background Fabrication of two membrane sensors using two acidic indicators among sulphonthalein dyes, namely bromophenol blue (BPB) and bromocresol green (BCG), and their use as indicative electrodes for the quantification of frusemide (FUR) is presented. The ion pair complexes of FUR with BPB or BCG are used to prepare the membranes in THF solvent, PVC matrix and dibutyl phthalate (DBP) as plasticizer and subsequently to fabricate FUR-BPB (Sensor I) and FUR-BCG (Sensor II) sensors. Results Sensors I and II are employable to determine 2.4 × 10-5–2.4 × 10-3 mol/L FUR at operative pH of 3.71. The calibration curve between the potentials against the concentration of FUR yielded the slopes of 58.73 ± 1 and 57.66 ± 1 mV/decade, respectively, using Sensors I and II, and this confirmed the Nernstian behaviour. Satisfactory correlation was obtained between the measured potentials and FUR concentration with the proposed sensors, and this was revealed by regression coefficient values of 0.9987 and 0.9980 for Sensors I and II, respectively. The LOD (limit of detection) values were calculated and reported for both the sensors. The experimental parameters were optimised to yield acceptable characteristics of both the sensors in the context of performance. The role of excipients of tablets and interferences were assessed by standard addition protocol. The obtained results confirmed the ineffective role of excipients of tablets and foreign species used as interferents. Conclusion The designed sensors were validated to confirm the accurate, precise, robust and rugged functioning in determining FUR. The mean of recovered FUR, close to 100%, revealed the acceptable and effective functioning of the proposed sensors. Excellent results were obtained by FUR tablets’ analysis using both the sensors.

scholarly journals Characteristic Times for the Fermi–Ulam Model

2021 ◽  
Vol 31 (02) ◽  
pp. 2130004
Author(s):  
Joelson D. Veloso Hermes ◽  
Edson D. Leonel
Keyword(s):  
Fractal Dimension ◽  
Phase Space ◽  
Lyapunov Exponent ◽  
Direct Determination ◽  
Recurrence Time ◽  
Invariant Curves ◽  
Lyapunov Time ◽  
Normal Diffusion ◽  
The Mean

The mean Poincaré recurrence time as well as the Lyapunov time are measured for the Fermi–Ulam model. It is confirmed that the mean recurrence time is dependent on the size of the window chosen in the phase space where particles are allowed to return. The fractal dimension of the region is determined by the slope of the recurrence time against the size of the window and two numerical values are measured: (i) [Formula: see text] confirming normal diffusion for chaotic regions far from periodic domains and (ii) [Formula: see text] leading to anomalous diffusion measured inside islands of stability and invariant curves corresponding to regular orbits, a signature of local trapping of an ensemble of particles. The Lyapunov time is the inverse of the Lyapunov exponent. Therefore, the Lyapunov time is measured over different domains in the phase space through a direct determination of the Lyapunov exponent.

scholarly journals A symmetrical method to obtain shear moduli from microrheology

Soft Matter ◽  
2018 ◽  
Vol 14 (19) ◽  
pp. 3716-3723 ◽  
Author(s):  
Kengo Nishi ◽  
Maria L. Kilfoil ◽  
Christoph F. Schmidt ◽  
F. C. MacKintosh
Keyword(s):  
Elastic Moduli ◽  
Direct Determination ◽  
Analysis Method ◽  
Shear Moduli ◽  
Mean Squared Displacement ◽  
The Mean ◽  
Symmetrical Method ◽  
Probe Particles

Passive microrheology deduces shear elastic moduli from thermally fluctuating motion of probe particles. We introduce and test an analysis method for direct determination of these moduli from the mean-squared displacement of a probe.

A Novel Method For The Direct Determination Of Platelet-Associated IgG (PAIgG) Employing Rocket Immunoelectrophoresis (Laurell)

1981 ◽  
Author(s):  
T J Kunicki ◽  
S M Kristopeit ◽  
R H Aster
Keyword(s):  
Direct Determination ◽  
Human Platelets ◽  
Rabbit Antibody ◽  
Human Igg ◽  
Novel Method ◽  
The Mean ◽  
Triton X ◽  
Phosphate Buffered Saline ◽  
Indirect Assay

The diagnosis and management of immune thrombocytopenia requires an effective method for the quantitation of platelet- associated IgG (PAIgG). Although several methods have been recently devised for this purpose, the search continues for a method which will prove to be accurate and reproducible, and yet simple enough to be utilized by the general clinical hemostasis laboratory. We now describe the development of an assay for PAIgG which we believe satisfies these criteria.Human platelets were isolated by differential centrifugation, washed five times in Tris-HCl pH 7.4 or phosphate buffered saline pH 7.4, both containing 5mM EDTA, and disrupted in 0.1M sodium acetate buffer pH 5.0 containing 1% (v/v) Triton X-100. Rabbit antibody specific for γ chains of human IgG (purified IgG fraction from DAKO) was carbamylated such that its isoelectric point was decreased to roughly 5.0. Total PAIgG was measured by electrophoresis at pH 5.0 of Triton X-100 disrupted washed platelets against the carbamylated rabbit anti-human IgG (γ) in 1% agarose gels containing 0.5% Triton X-100.The mean total PAIgG for 8 normals, was 5.7 fg/platelet (range 4.9 to 7.0). This technique is applicable to the quantitation of alloantibodies bound to normal platelets (indirect assay) as well as the quantitation of PAIgG on platelets of individuals with immune thrombocytopenic states, such as ITP.

scholarly journals Asteroid Masses and Densities

1971 ◽  
Vol 12 ◽  
pp. 33-39 ◽  
Author(s):  
Joachim Schubart
Keyword(s):  
Total Mass ◽  
Direct Determination ◽  
Absolute Magnitude ◽  
Strong Increase ◽  
Minor Planets ◽  
Solar Mass ◽  
A Value ◽  
The Mean ◽  
The Masses

Before 1966, when Hertz (1966) published his first direct determination of the mass of Vesta, all our knowledge on asteroid masses was based on estimates. The masses of the first four minor planets resulted from the measured diameters by Barnard (1900) (see the paper by Dollfus in this volume) and from estimated mean densities. The diameters of the smaller objects were derived from their brightness and an estimate of their reflectivity (usually the reflectivity of the Moon was adopted). In 1901, Bauschinger and Neugebauer (1901) derived a value for the total mass of the first 458 asteroids. All the diameters were computed from the brightness with an assumed value for the reflectivity. The diameter of Ceres found in this way is very close to Barnard’s (1900) value. The mean density of the 458 asteroids was put equal to that of Earth, and their total mass resulted as 3 X 10-9 solar mass. Stracke (1942) used the same method with an increased material, but the addition of more than 1000 faint asteroids did not bring a significant change in the estimate of the total mass. The report on the McDonald asteroid survey (Kuiper et al., 1958) does not contain another estimate of the total mass of the asteroid ring, but it points to the possibility of a very rapid increase in the number of asteroids with decreasing absolute brightness. If this increase is strong enough, each interval of 1 mag in absolute magnitude can contribute the same amount to the total mass. In the range of magnitudes covered by the Palomar-Leiden survey (PLS) (van Houten et al., 1970), there are no indications for such a strong increase.

scholarly journals Objective determination of northeast monsoon onset dates over coastal Tamil Nadu for the period 1901-90

MAUSAM ◽  
2021 ◽  
Vol 43 (3) ◽  
pp. 273-282
Author(s):  
Y. E. A. RAJ
Keyword(s):  
Tamil Nadu ◽  
Daily Rainfall ◽  
Onset Date ◽  
Northeast Monsoon ◽  
Objective Method ◽  
Abrupt Increase ◽  
Statistical Parameters ◽  
The Mean ◽  
Objective Determination

The onset dates of northeast monsoon over coastal Tamil Nadu have been determined by adopting an objective method for the years 1901-90. The various statistical parameters associated with onset dates have been computed and interpreted. Relation between onset dates of easterlies and northeast monsoon over Tamil Nadu has been examined. The normal date obtained has been shown to be by and large consistent with the characteristics of normal daily rainfall of coastal Tamil Nadu. The superposed epoch method has been, used to compute the mean rainfall with reference to onset date and the abrupt increase in rainfall at onset has been clearly brought out The spatial distribution and intensity of rainfall at the time of onset have also been discussed. Daily rainfall has been graphically presented for some years with spectacular onset as well as for some years with subdued onset.

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