scholarly journals Photographic Observation of Stellar Occultations

1988 ◽  
Vol 98 ◽  
pp. 144-145
Author(s):  
A. Tomić ◽  
N. Čabrić ◽  
V. Čelebonović

Stellar occultations are usually observed visually, but this can also be done photographically. Our method has some advantages: –the obtained moments of contacts refer to the smoothed lunar limb,–the error in the determination of contacts is calculable,–the error may be less than in visual work,–the reduction of photographs is fast, due to the application of an “on-line” computer [1].In order to achieve all this, it is necessary to make a series of photographs of the Moon and the object being occulted before the first and after the last contact. This is a crucial step in our method, because the photographs must be of high quality. This demands two things: –the images of the occulted object and the Moon must be reliably recorded and–the illuminated limb of the Moon must give optimal darkening on the film.

2011 ◽  
Vol 26 (S2) ◽  
pp. 758-758
Author(s):  
J.A. García ◽  
A.S. Raya ◽  
E.S. del Arco

The graphic papers of Pablo, 14 years, diagnosed of autism of high functioning, serve as a sign of alert when facing what underlies after the specializing professional intervention.A few letters, a few drawings, and a few words that show the powerlessness, the suffering and the absence of contextual specific adequacy.In this work we study, from the analysis of a real case, some excellent aspects in the psychosociosanitary attention, such as:-The need for compilation of pertinent information-The need for elimination of prejudices-The need for respect to the family-The need for specialized formation-The need for search of a shared communicative code-The need for search of strategies of social interaction-The need for empathy-The need for search of contextual specific adequacy-The need for rigorous rules in the physical containment.-The need of a turned over of adapted information-The need to respect the psychoevolutive situation of the patient-The need to give priority to the person on the illness.A testimony that should serve as a warning for those institutions, administrations and professionals who are thinking of having put all the resources to its scope.A testimony that should serve to contribute information and new challenges to those other professionals who do not stop their determination of conceptual and/or clinical anxious research.


Author(s):  
John J. Donovan ◽  
Mark L. Rivers

Although several commercial automation packages are available for use on the micro-probe, we at Berkeley feel that they all suffer from a number of shortcomings. A few of the most important features missing are :1.The ability to produce quantitative results of the highest accuracy over the entire analytical range of the micro-probe using the most advanced matrix correction software available.2.A simple yet versatile user interface making extensive use of multiple choice menus and defaulted experimental parameters for exceptional ease of use.3.Full support of manual and automated modes for both standard and unknown samples for a wide variety of sample configurations and analytical methods.4.Hardware independence and completely configurable program for various micro-probe stage and spectrometer arrangements for use with any micro-probe hardware.5.Capability on a PC for BOTH real-time on-line data acquisition and analysis when connected to the micro-probe, and off-line analysis of data when not connected.6.Ability to run on an inexpensive and widely available computer platform without the need for graphics hardware.


2019 ◽  
Vol 104 (6) ◽  
pp. e31.1-e31
Author(s):  
M Feickert ◽  
I Burdman ◽  
N Makowski ◽  
M Ali ◽  
S Farahani ◽  
...  

BackgroundAs the initiator of the Renin-Angiotensin-Aldosterone-system, renin plays an essential role in the vicious circle of heart failure. Therefore, renin was determined in the investigators driven ‘Labelling of Enalapril from neonates up to adolescents’ (LENA) study to evaluate its role in paediatric heart failure. Due to the often long-lasting periods of recruitment of paediatric subjects, the assay performance has to be guaranteed over the whole recruiting time. Therefore, to ensure the high quality of the determined renin study samples after successful assay validation,1 a multi-step quality approach was used to get reliable results over a period of 30 months.MethodsBased on a multi-step quality approach consisting of calibration standards (CSs), quality controls (QCs) and incurred sample reanalysis (ISR), study samples of unknown renin concentrations were determined. Results within predefined limits of CSs (6 levels) and QCs according to European Medicine Agency (EMA) guidelines were required for evaluating the study samples.2 ISR was performed for randomly selected paediatric samples to evaluate the long-term accuracy of the validated assay.Results133 analytical runs were conducted for renin from February 2016 to August 2018. In 119 (88.8%) valid runs, a total number of 1414 of CCs and 952 of QCs were determined. Thereof 99.9% of CCs and 98.3% of QCs were in the predefined limits according to EMA. 143 incurred sample pairs were reanalysed resulting in 95.8% of samples within EMA guidelines. Using this multi-step quality approach, the reliable determination of 965 LENA paediatric study samples was guaranteed.ConclusionIn addition to the assay validation, the multi-step quality approach ensured the reliability of the determined renin concentrations in the continuous bioanalysis of the paediatric study samples and guaranteed the high quality of the collected data in the LENA study.ReferencesSchaefer J, Burckhardt BB, Tins J, et al. Validated low-volume immunoassay for the reliable determination of direct renin especially valuable for pediatric investigations. J Immunoass Immunochem 2017;38:579–94. doi:10.1080/15321819.2017.1350707Guideline on bioanalytical method validation. European Medicines Agency, London, UK (2011).Disclosure(s)Martin Feickert, Ilja Burdman, Nina Makowski, Moshin Ali, Anke Bartel, and Bjoern B. Burckhardt declare that there is no conflict of interest. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n°602295 (LENA)


1946 ◽  
Vol 50 (432) ◽  
pp. 974-985 ◽  
Author(s):  
E. K. Frankl

The photo-elastic method can be used for either of two main purposes:a)As a qualitative design tool to obtain indications of possibly unsuspected sources of stress concentration.(b)As a means of obtaining a complete analysis of a two-dimensional stress problem, i.e., the determination of the separate magnitudes of the principal stresses at any point, as well as the direction of the principal planes relative to some axis of reference.All that is required for (a) is the stress pattern which becomes visible and can be photographed when a loaded model cut from a sheet of suitable material is placed in a field of circularly polarised light.


1990 ◽  
Vol 141 ◽  
pp. 482-482 ◽  
Author(s):  
V. V. Nesterov ◽  
V. S. Kisliuk ◽  
H. I. Potter

The goal of the present study is (1)Completion of a general reduction of the Carte du Ciel astrophotographic catalogs, measurement of the positions in them on modern astronegatives, derivation of proper motions and compilation of a catalog of stars to magnitude 12.5.(2)Copying the data of all 272 volumes of astrophotographic catalogues onto magnetic tapes (all together 8.5 million measurements).(3)Measurement of modern astronegatives on FON-OBZOR-S and FOKAT-Y programs.(4)Studies of the magnitude equation of the AGK3 catalog and other catalogs which will be presumably used as reference catalogs.(5)Development and comparative studies of several methods of determination of equatorial coordinates on the basis of full information on astronegative measurements. Application of these methods to compilation of the catalog of 4 million stars.


1961 ◽  
Vol 5 ◽  
pp. 1-12
Author(s):  
Andre Guinier

AbstractAlthough no revolutionary advance has been achieved in the last two decades, X-ray diffraction is not to be considered as a quiescent field of physics. Actually many improvements, in theory as well as in experiment, slight by themselves but very numerous, have considerably increased the efficiency of techniques such as the determination of crystal structures, the analysis of crystalline phases, and the applications of X-rays to various problems of the physics of solids. Only the two last points will be dealt with here:1.Crystalline phase analysis. The development of a satisfactory atlas of powder patterns has been too slow, and the data are not yet complete and precise enough to permit a rational utilization of the modern diffractometers. A very interesting new approach is the systematic indexing of the powder patterns which would be possible with computers. In the near future, anyone should be able to analyze a powder at any temperature as an easy routine experiment.2.The study of lattice defects. X-ray techniques are now in competition with electron microscopy, the development of which has been very successful in recent years. Now we have a better understanding of the possibilities of both techniques. X-rays give better results to determine the statistics of an extended disorder even if it is slight (e.g., degrees of order in a solid solution), and the microscope is more powerful for the detection of large but rare defects (e.g., dislocations).


1978 ◽  
Vol 80 ◽  
pp. 433-436
Author(s):  
H.E. Jørgensen

Today we know accurate masses, radii, surface gravities and luminosities or effective temperatures of a very small number of stars. There are several reasons for deriving accurate parameters of stars. I shall mention only four problems:(i)checking stellar evolution calculations, particularly calculations of isochrones, using binaries,(ii)derivation of helium content in stars of different age,(iii)checking log g derived from photometry and stellar atmosphere calculations,(iv)determination of accurate positions in the HR diagram to get an independent check on calibrations of photometric systems.


1975 ◽  
Vol 26 ◽  
pp. 93-114
Author(s):  
R. S. Mather

AbstractThe requirements for systems of reference in geodesy and ocean dynamics should be framed against the background of the distinct possibility of achieving in the foreseeable future measurements with a resolution of 1 part in 108. The current techniques promising this precision, with one exception, are based on observations to extraterrestrial sources/responders. The principal geodetic goals calling for such precision are, broadly stated, the determination of:1. Positions of stations in global tracking networks.2. Crustal motion.3. Polar motion.4. The radial component of instantaneous sea surface position from satellite altimetry for the estimation of phenomena related to ocean circulation.5. Earth model improvement.These goals cannot be achieved without the definition of adequate models for relating measurements from observing stations on Earth to extraterrestrial objects, possibly in an iterative manner in the first instance.While the specific choice of a system of geodetic reference is not critical for determinations of position in three dimensions, the maintenance of the continuity of geodetic concepts at the highest level of resolution in terms of four-dimensional considerations narrows the possible alternatives available.Criteria desirable in such a system of reference for observations of the highest precision made from the surface of a non-rigid Earth undergoing secular crustal motion are the following:1. These observations should be capable of direct relation to the system of reference in four dimensions.2. The crustal motion vector at a point should be defined in terms of the variations of the coordinatesof that pointwith time.3. Near-Earth orbital positions should have unambiguous relationships to the origin of ocean geoid determinations in four dimensions.4. Coordinates on the adopted system of reference should have relevance over an epoch of practical significance (e.g., one year).5. The scale for the space as obtained from the observations should not be influenced by factors other than the velocity of light and the adopted definition for the second.An important corollary is that only one point should be treated as “fixed” at the surface of the nonrigid Earth. Positional variations which have a periodic character, effective over an epoch of observation or less, are best treated as effects to be removed from observations by appropriate modeling. Reported secular changes in mean sea level require that the geoid be defined in relation to mean sea level in four dimensions for any determination of sea surface topography, thereby completing a unified system of reference which, would meet all the requirements of high-precision geodesy and ocean dynamics.


Radiocarbon ◽  
1963 ◽  
Vol 5 ◽  
pp. 254-272 ◽  
Author(s):  
Carl L. Hubbs ◽  
George S. Bien ◽  
Hans E. Suess

During 1962 the La Jolla Radiocarbon Laboratory continued to follow essentially the same technique as in previous years. Three counters were used: 1.The “Bern Counter,” an Oeschger-Houtermans instrument manufactured at the Physical Institute of the University of Bern; described in La Jolla I (p. 197).2.The “Brussels Counter,” another Oeschger-Houtermans instrument, manufactured in Brussels by Manufacture Belge de Campes et de Matériel Électronique, S. A.; characterized in La Jolla II (p. 204).3.The “400-cc La Jolla Counter,” recently constructed at the University of California, San Diego to facilitate the age determination of samples containing less than 1 g of carbon. Because the first model, now in use, was constructed of brass—not the optimal material—the background count is relatively high (ca. 5.0 counts/min). Advantages lie in its high stability. For samples that yield 0.5 L or more of acetylene, this counter can be used quite satisfactorily. Check runs, using the same sample in this counter and in the Bern and Brussels counters, agree closely.


2018 ◽  
Author(s):  
Leonardo Claudino ◽  
Sara J Hussain ◽  
Ethan R Buch ◽  
Leonardo G Cohen

AbstractOBJECTIVETranscranial magnetic stimulation (TMS) is extensively used in basic and clinical neuroscience. Previous work has shown substantial residual variability in TMS effects even despite use of on-line visual feedback monitoring of coil position. Here, we aimed to evaluate if off-line denoising of variability induced by neuronavigated coil position and orientation deviations can enhance detection of TMS effects.METHODSRetrospective modeling was used to denoise the impact of common neuronavigated coil position and rotation deviations during TMS experimental sessions on motor evoked potentials (MEP) to single pulse TMS.RESULTSNeuronavigated coil deviations explained approximately 44% of total MEP amplitude variability. Offline denoising led to a 136.71% improvement in the signal to noise ratio (SNR) of corticospinal excitability measurements. CONCLUSIONS: Offline modeling enhanced detection of TMS effects by removing variability introduced by neuronavigated coil deviations.SIGNIFICANCEThis approach could allow more accurate determination of TMS effects in cognitive and interventional neuroscience.HIGHLIGHTSCoil deviations impact TMS effects despite use of on-line neuronavigation feedback.Offline denoising of coil deviation impacts on TMS effects significantly reduced variability at trial level.Offline denoising also significantly improved overall SNR of TMS effects.


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