scholarly journals OPTIMIZATION OF A VIBRATING SAMPLE MAGNETOMETER FOR A LABORATORY PHYSICS COURSE

2017 ◽  
Vol 26 (2) ◽  
pp. 27 ◽  
Author(s):  
Félix L. Avilés ◽  
Elmer Monteblanco ◽  
Abel Gutarra
Keyword(s):  
Condensed Matter ◽  
Oscillation Amplitude ◽  
Real Problem ◽  
Vibrating Sample Magnetometer ◽  
Induced Voltage ◽  
Frequency Oscillation ◽  
Palabras Clave ◽  
The One ◽  
Physics Course

ABSTRACTThis paper describes the implementation and a detailed optimization of a Vibrating Sample Magnetometer (VSM) for an undergraduate physics course laboratory. The VSM operation parameters were extensively discussed using Foner and Mallison coils configuration. The influence of the involved parameters (e.g. oscillation frequency, oscillation amplitude, rate change of the external magnetic field, coils configuration, etc.) on the induced voltage in the pick-up coils were discussed. A disk of nickel of 6-mm diameter was used for the calibration of the magnetometer, comparing the hysteresis loop measured with our magnetometer with the one obtained using a commercial VSM. Magnetization curves of two different samples were obtained in order to test the sensitivity of the magnetometer. The vibrating sample magnetometer implemented in the present work is able to detect changes in the total magnetic moment down to 10-3 emu. The detailed optimization of the VSM described in the present work is an example of how to solve a real problem in condensed matter, related to the determination of the magnetization value of a magnetic sample. Keywords.- : Vibrating sample magnetometer, Magnetometry, Instrumentation. RESUMEN Este artículo describe la implementación y una optimización detallada de un magnetómetro de muestra vibrante (VSM) para un laboratorio de licenciatura en física. Los parámetros de operación de VSM se discutieron ampliamente usando la configuración de bobinas de Foner y Mallison. Se discutió la influencia de los parámetros implicados (por ejemplo, frecuencia de oscilación, amplitud de oscilación, cambio de velocidad del campo magnético externo, configuración de bobinas, etc.) sobre la tensión inducida en las bobinas de captación. Se utilizó un disco de níquel de 6 mm de diámetro para la calibración del magnetómetro, comparando el bucle de histéresis medido con nuestro magnetómetro con el obtenido utilizando un VSM comercial. Se obtuvieron curvas de magnetización de dos muestras diferentes para probar la sensibilidad del magnetómetro. El magnetómetro de muestra vibrante implementado en el presente trabajo es capaz de detectar cambios en el momento magnético total hasta 10-3 emu. La optimización detallada del VSM descrita en el presente trabajo es un ejemplo de cómo resolver un problema real en materia condensada, relacionado con la determinación del valor de magnetización de una muestra magnética. Palabras clave.-Magnetómetro de muestra vibrante, Magnetometría, Instrumentación,

scholarly journals Fusiones internacionales, libertad de establecimiento y derechos de los acreedores. Cuestiones abiertas por la STJ (Sala Tercera) de 7 de abril de 2016 (as. C-483/14, KA Finanz AG y Sparkassen Versicherung AG Vienna Insurance Group) = International mergers, freedom of establishment and creditor’s rights. Open questions in the judgment of the court of justice (third chamber) of 7th april 2016 (as. C-483/14, KA Finanz AG and Sparkassen Versicherung AG Vienna Insurance Group)

2017 ◽  
Vol 9 (2) ◽  
pp. 570
Author(s):  
Rafael Arenas García
Keyword(s):  
Company Law ◽  
Freedom Of Establishment ◽  
Open Questions ◽  
Insurance Group ◽  
Palabras Clave ◽  
International Mergers ◽  
The One ◽  
Special Rights ◽  
The Relationship

Resumen: La sentencia KA Finanz ofrece al Tribunal de Luxemburgo la oportunidad de pronunciarse sobre varias cuestiones relevantes en materia de fusiones internacionales. En concreto sobre las relaciones entre el Derecho rector de las obligaciones de las que son parte las sociedades que intervienen en la fusión y la que se aplica a este operación; la determinación del Derecho rector de la fusión y ciertos límites en las posibilidades de regular las garantías de los acreedores en las fusiones internacionales. Además, interpreta qué ha de entenderse por titulares de títulos a los que correspondan derechos especiales (art. 15 de la Directiva 78/855/CEE).Palabras clave: Derecho de sociedades, libertad de establecimiento, fusiones internacionales, protección de los acreedores.Abstract: The KA Finanz judgment allows the Luxembourg Court to deal with some relevant issues connected to international mergers. Specifically, on the relationship between the laws governing the obligations of which the companies involved in the merger are parties, and the one that applies to the merger; the determination of the law governing the merger and also on certain limits of the national legislators in the regulation of the creditor’s guarantees in international mergers. Furthermore, it interprets what is to be understood by holders of securities to which special rights are attached (article 15 of Directive 78/855 / EEC).Keywords: Company law, freedom of establishment, international mergers, protection of the interest of creditors.

scholarly journals Sobre la peligrosa idea de un “libre” mercado

2019 ◽  
pp. 46-55
Author(s):  
Rodrigo Maruy Van Den Broek
Keyword(s):  
Government Regulation ◽  
Free Market ◽  
Supply And Demand ◽  
Government Policies ◽  
Palabras Clave ◽  
The One ◽  
Definition Of

ResumenEl presente texto consiste en una problematización del uso corriente del concepto de “libre” mercado. Por un lado, exploraremos hasta qué punto la definición del libre mercado como la ausencia de regulación gubernamental que permite las fluctuaciones de la oferta y la demanda es, o no, históricamente precisa. Por otro lado, se pondrá en tela de juicio la posibilidad de interpretar al libre mercado como un ideal normativo hacia el cual la sociedad debería tender. A modo de conclusión, enfatizaremos la necesidad y la importancia de explicitar el contenido de conceptos económicos cuyo uso se encuentra estrechamente vinculado con la determinación de políticas y modelos gubernamentales. Palabras clave: libre mercado, oferta y demanda, racionalidad liberal, ideología, patologías sociales. Abstract:This paper consists of a discussion about the current use of the concept of “free” market. On the one hand, we will explore to what extent is historically accurate the definition of free market as the absence of government regulation that allows variations in supply and demand. In addition, the possibility of interpreting the free market as a normative ideal towards which society should tend will be questioned. In conclusion, we will emphasize the need and importance of making explicit the content of economic concepts whose use is closely linked to the determination of government policies and models. Keywords: Free market, supply and demand, liberal rationality, ideology, social pathologies

Two-Stage Procedure for the Quantitative Determination of Autoprothrombin III Concentration and Some Applications

1967 ◽  
Vol 18 (01/02) ◽  
pp. 198-210 ◽  
Author(s):  
Ronald S Reno ◽  
Walter H Seegers
Keyword(s):  
Prothrombin Time ◽  
Factor Vii ◽  
Two Stage ◽  
Pronounced Increase ◽  
One Stage ◽  
Assay Procedure ◽  
Bovine Plasma ◽  
The One ◽  
Autoprothrombin C

SummaryA two-stage assay procedure was developed for the determination of the autoprothrombin C titre which can be developed from prothrombin or autoprothrombin III containing solutions. The proenzyme is activated by Russell’s viper venom and the autoprothrombin C activity that appears is measured by its ability to shorten the partial thromboplastin time of bovine plasma.Using the assay, the autoprothrombin C titre was determined in the plasma of several species, as well as the percentage of it remaining in the serum from blood clotted in glass test tubes. Much autoprothrombin III remains in human serum. With sufficient thromboplastin it was completely utilized. Plasma from selected patients with coagulation disorders was assayed and only Stuart plasma was abnormal. In so-called factor VII, IX, and P.T.A. deficiency the autoprothrombin C titre and thrombin titre that could be developed was normal. In one case (prethrombin irregularity) practically no thrombin titre developed but the amount of autoprothrombin C which generated was in the normal range.Dogs were treated with Dicumarol and the autoprothrombin C titre that could be developed from their plasmas decreased until only traces could be detected. This coincided with a lowering of the thrombin titre that could be developed and a prolongation of the one-stage prothrombin time. While the Dicumarol was acting, the dogs were given an infusion of purified bovine prothrombin and the levels of autoprothrombin C, thrombin and one-stage prothrombin time were followed for several hours. The tests became normal immediately after the infusion and then went back to preinfusion levels over a period of 24 hrs.In other dogs the effect of Dicumarol was reversed by giving vitamin K1 intravenously. The effect of the vitamin was noticed as early as 20 min after administration.In response to vitamin K the most pronounced increase was with that portion of the prothrombin molecule which yields thrombin. The proportion of that protein with respect to the precursor of autoprothrombin C increased during the first hour and then started to go down and after 3 hrs was equal to the proportion normally found in plasma.

SIMPLIFIED DEXAMETHASONE SUPPRESSION TEST

1969 ◽  
Vol 61 (2) ◽  
pp. 219-231 ◽  
Author(s):  
V. H. Asfeldt
Keyword(s):  
Cushing’S Syndrome ◽  
Normal Subjects ◽  
Cushing's Syndrome ◽  
Dexamethasone Suppression Test ◽  
Clinical Value ◽  
Suppression Test ◽  
The One ◽  
Steroid Excretion ◽  
Dexamethasone Suppression

ABSTRACT This is an investigation of the practical clinical value of the one mg dexamethasone suppression test of Nugent et al. (1963). The results, evaluated from the decrease in fluorimetrically determined plasma corticosteroids in normal subjects, as well as in cases of exogenous obesity, hirsutism and in Cushing's syndrome, confirm the findings reported in previous studies. Plasma corticosteroid reduction after one mg of dexamethasone in cases of stable diabetes was not significantly different from that observed in control subjects, but in one third of the insulin-treated diabetics only a partial response was observed, indicating a slight hypercorticism in these patients. An insufficient decrease in plasma corticosteroids was observed in certain other conditions (anorexia nervosa, pituitary adenoma, patients receiving contraceptive or anticonvulsive treatment) with no hypercorticism. The physiological significance of these findings is discussed. It is concluded that the test, together with a determination of the basal urinary 17-ketogenic steroid excretion, is suitable as the first diagnostic test in patients in whom Cushing's syndrome is suspected. In cases of insufficient suppression of plasma corticosteroids, further studies, including the suppression test of Liddle (1960), must be carried out.

A Validated 2D-LC-UV Method for Simultaneous Determination of Imatinib and N-demethylimatinib in Plasma and Its Clinical Application for Therapeutic Drug Monitoring with GIST Patients

2020 ◽  
Vol 17 ◽  
Author(s):  
Houli Li ◽  
Di Zhang ◽  
Xiaoliang Cheng ◽  
Qiaowei Zheng ◽  
Kai Cheng ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
One Dimension ◽  
Therapeutic Drug ◽  
Plasma Samples ◽  
Column Temperature ◽  
Injection Volume ◽  
Target Analytes ◽  
The One ◽  
Middle Column

Background: The trough concentration (Cmin) of Imatinib (IM) is closely related to the treatment outcomes and adverse reactions of patients with gastrointestinal stromal tumors (GIST). However, the drug plasma level has great interand intra-individual variability, and therapeutic drug monitoring (TDM) is highly recommended. Objective: To develop a novel, simple, and economical two-dimensional liquid chromatography method with ultraviolet detector (2D-LC-UV) for simultaneous determination of IM and its major active metabolite, N-demethyl imatinib (NDIM) in human plasma, and then apply the method for TDM of the drug. Method: Sample was processed by simple protein precipitation. Two target analytes were separated on the one-dimension column, captured on the middle column, and then transferred to the two-dimension column for further analysis. The detection was performed at 264 nm. The column temperature was maintained at 40˚C and the injection volume was 500 μL. Totally 32 plasma samples were obtained from patients with GIST who were receiving IM. Method: Sample was processed by simple protein precipitation. Two target analytes were separated on the one-dimension column, captured on the middle column, and then transferred to the two-dimension column for further analysis. The detection was performed at 264 nm. The column temperature was maintained at 40˚C and the injection volume was 500 μL. Totally 32 plasma samples were obtained from patients with GIST who were receiving IM. Conclusion: The novel 2D-LC-UV method is simple, stable, highly automated and independent of specialized technicians, which greatly increases the real-time capability of routine TDM for IM in hospital.

scholarly journals The Concept of Accuracy Analysis of the Vertical Displacements Gained from the Hydrostatic Levelling Systems’ Measurements

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4842
Author(s):  
Waldemar Kamiński
Keyword(s):  
Accuracy Assessment ◽  
Theoretical Models ◽  
Vertical Displacement ◽  
Serial Connection ◽  
Vertical Displacements ◽  
Comprehensive Determination ◽  
The One ◽  
The Individual ◽  
Reference Sensor

Nowadays, hydrostatic levelling is a widely used method for the vertical displacements’ determinations of objects such as bridges, viaducts, wharfs, tunnels, high buildings, historical buildings, special engineering objects (e.g., synchrotron), sports and entertainment halls. The measurements’ sensors implemented in the hydrostatic levelling systems (HLSs) consist of the reference sensor (RS) and sensors located on the controlled points (CPs). The reference sensor is the one that is placed at the point that (in theoretical assumptions) is not a subject to vertical displacements and the displacements of controlled points are determined according to its height. The hydrostatic levelling rule comes from the Bernoulli’s law. While using the Bernoulli’s principle in hydrostatic levelling, the following components have to be taken into account: atmospheric pressure, force of gravity, density of liquid used in sensors places at CPs. The parameters mentioned above are determined with some mean errors that influence on the accuracy assessment of vertical displacements. In the subject’s literature, there are some works describing the individual accuracy analyses of the components mentioned above. In this paper, the author proposes the concept of comprehensive determination of mean error of vertical displacement (of each CPs), calculated from the mean errors’ values of components dedicated for specific HLS. The formulas of covariances’ matrix were derived and they enable to make the accuracy assessment of the calculations’ results. The author also presented the subject of modelling of vertical displacements’ gained values. The dependences, enabling to conduct the statistic tests of received model’s parameters, were implemented. The conducted tests make it possible to verify the correctness of used theoretical models of the examined object treated as the rigid body. The practical analyses were conducted for two simulated variants of sensors’ connections in HLS. Variant no. I is the sensors’ serial connection. Variant no. II relies on the connection of each CPs with the reference sensor. The calculations’ results show that more detailed value estimations of the vertical displacements can be obtained using variant no. II.

scholarly journals Determination of the Height of Hard X-Ray Sources in the Solar Atmosphere by Measurement of Photospheric Albedo Photons

1975 ◽  
Vol 68 ◽  
pp. 239-241
Author(s):  
John C. Brown ◽  
H. F. Van Beek
Keyword(s):  
Solar Atmosphere ◽  
The Other ◽  
X Ray ◽  
Theoretical Predictions ◽  
Source Models ◽  
The One

SummaryThe importance and difficulties of determining the height of hard X-ray sources in the solar atmosphere, in order to distinguish source models, have been discussed by Brown and McClymont (1974) and also in this Symposium (Brown, 1975; Datlowe, 1975). Theoretical predictions of this height, h, range between and 105 km above the photosphere for different models (Brown and McClymont, 1974; McClymont and Brown, 1974). Equally diverse values have been inferred from observations of synchronous chromospheric EUV bursts (Kane and Donnelly, 1971) on the one hand and from apparently behind-the-limb events (e.g. Datlowe, 1975) on the other.

Stochastic Models for Actuarial Use: The Equilibrium Modelling of Local Markets

2009 ◽  
Vol 39 (1) ◽  
pp. 339-370 ◽  
Author(s):  
Robert J. Thomson ◽  
Dmitri V. Gott
Keyword(s):  
Local Market ◽  
Market Participants ◽  
Market Portfolio ◽  
One Year ◽  
The One ◽  
Mean Variance ◽  
Annual Time ◽  
Time Subject

AbstractIn this paper, a long-term equilibrium model of a local market is developed. Subject to minor qualifications, the model is arbitrage-free. The variables modelled are the prices of risk-free zero-coupon bonds – both index-linked and conventional – and of equities, as well as the inflation rate. The model is developed in discrete (nominally annual) time, but allowance is made for processes in continuous time subject to continuous rebalancing. It is based on a model of the market portfolio comprising all the above-mentioned asset categories. The risk-free asset is taken to be the one-year index-linked bond. It is assumed that, conditionally upon information at the beginning of a year, market participants have homogeneous expectations with regard to the forthcoming year and make their decisions in mean-variance space. For the purposes of illustration, a descriptive version of the model is developed with reference to UK data. The parameters produced by that process may be used to inform the determination of those required for the use of the model as a predictive model. Illustrative results of simulations of the model are given.

The determination of the specific activity of plasma glycerol

1982 ◽  
Vol 60 (6) ◽  
pp. 856-858 ◽  
Author(s):  
Clément Gauthier ◽  
Ross Layberry
Keyword(s):  
Column Chromatography ◽  
Turnover Rate ◽  
Specific Activity ◽  
Anionic Exchange ◽  
Removal Of Contaminants ◽  
The One ◽  
Exchange Resins

A method for the determination of the specific activity of plasma glycerol is described. Anionic contaminants are first removed from deproteinized plasma by anionic exchange resins (treated plasma). Glycerol in treated plasma is then quantitatively converted to glycerol-3-phosphate (G3P), which is isolated by column chromatography and counted for 14C radioactivity. The specific activity thus calculated was 100.1 ± 2.9% of a standard of known specific activity. When the specific-activity of glycerol is determined from plasma without prior removal of anionic contaminants (untreated plasma), the calculated specific activity is 1.99 ± 0.15 times higher than the one calculated after their removal. Omission of the removal of contaminants leads to a near 100% error in the calculation of the turnover rate of glycerol.not available

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