scholarly journals On the Spectral and Polarimetric Signatures of a Bright Scatterer before and after Hardware Replacement

2021 ◽  
Vol 13 (5) ◽  
pp. 919
Author(s):  
Marco Gabella
Keyword(s):  
Low Noise ◽  
Low Noise Amplifiers ◽  
Doppler Velocity ◽  
Data Set ◽  
Differential Phase Shift ◽  
Spectral Signatures ◽  
Average Value ◽  
Before And After ◽  
Radar Calibration ◽  
Small Dispersion

A previous study has used the stable and peculiar echoes backscattered by a single “bright scatterer” (BS) during five winter days to characterize the hardware of C-band, the dual-polarization radar located at Monte Lema (1625 m altitude) in Southern Switzerland. The BS is the 90 m tall metallic tower on Cimetta (1633 m altitude, 18 km range). In this note, the statistics of the echoes from the BS were derived from other ten dry days with normal propagation conditions in winter 2015 and January 2019. The study confirms that spectral signatures, such as spectrum width, wideband noise and Doppler velocity, were persistently stable. Regarding the polarimetric signatures, the large values (with small dispersion) of the copolar correlation coefficient between horizontal and vertical polarization were also confirmed: the average value was 0.9961 (0.9982) in winter 2015 (January 2019); the daily standard deviations were very small, ranging from 0.0007 to 0.0030. The dispersion of the differential phase shift was also confirmed to be quite small: the daily standard deviation ranged from a minimum of 2.5° to a maximum of 5.3°. Radar reflectivities in both polarizations were typically around 80 dBz and were confirmed to be among the largest values observed in the surveillance volume of the Monte Lema radar. Finally, another recent 5-day data set from January 2020 was analyzed after the replacement of the radar calibration unit that includes low noise amplifiers: these five days show poorer characteristics of the polarimetric signatures and a few outliers affecting the spectral signatures. It was shown that the “historical” polarimetric and spectral signatures of a bright scatterer could represent a benchmark for an in-depth comparison after hardware replacements.

GESTOGENS IN CORPUS LUTEUM OF CATTLE

1960 ◽  
Vol XXXIII (III) ◽  
pp. 417-427 ◽  
Author(s):  
John Kristoffersen
Keyword(s):  
Corpus Luteum ◽  
Average Value ◽  
Spectrophotometric Methods ◽  
The Third ◽  
Quantitative Measurements ◽  
Before And After ◽  
Luteal Tissue ◽  
In Pregnancy

ABSTRACT By means of chromatographic and spectrophotometric methods progesterone and a substance closely similar to 20β-hydroxy-pregn-4-ene-3-one has been detected in luteal tissue from non-pregnant and pregnant cows. In 21 animals quantitative measurements based on a method giving an average net recovery of 56 per cent showed that in pregnancy the average progesterone content in the corpus luteum reached a maximum in the third to fifth month, with low values before and after this period. For 6 nonpregnant cows, the average value was 20.2 μg/g tissue, which is considerably higher than previous values reported in the literature. The relation between these findings and the bovine dependence on a functional corpus luteum in pregnancy is discussed, and it is pointed out that more information about the metabolism of progesterone in cattle is highly desirable.

A new method of fluxgate signal extraction

2017 ◽  
Vol 2017 (45) ◽  
pp. 83-89
Author(s):  
A.A. Marusenkov ◽  
Keyword(s):  
High Frequency ◽  
Second Harmonic ◽  
Excitation Frequency ◽  
Low Noise ◽  
Measuring System ◽  
Signal Extraction ◽  
Fluxgate Magnetometer ◽  
New Approach ◽  
Average Value ◽  
The Time Domain

Using dedicated high-frequency measuring system the distribution of the Barkhausen jumps intensity along a reversal magnetization cycle was investigated for low noise fluxgate sensors of various core shapes. It is shown that Barkhausen (reversal magnetization) noise intensity is strongly inhomogeneous during an excitation cycle. In the traditional second harmonic fluxgate magnetometers the signals are extracted in the frequency domain, as a result, some average value of reversal magnetization noises is contributed to the output signals. In order to fit better the noise shape and minimize its transfer to the magnetometer output the new approach for demodulating signals of these sensors is proposed. The new demodulating method is based on information extraction in the time domain taking into account the statistical properties of cyclic reversal magnetization noises. This approach yields considerable reduction of the fluxgate magnetometer noise in comparison with demodulation of the signal filtered at the second harmonic of the excitation frequency.

Dynamic Relationship between Crude Oil and Stock Prices in India: Before And After the Subprime Financial Crisis 2008

GIS Business ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. 96-104
Author(s):  
P. Sakthivel ◽  
S. Rajaswaminathan ◽  
R. Renuka ◽  
N. R.Vembu
Keyword(s):  
Financial Crisis ◽  
Crude Oil ◽  
Stock Prices ◽  
Oil Prices ◽  
Energy Index ◽  
Data Set ◽  
Dynamic Relationship ◽  
Crude Oil Prices ◽  
Long Run ◽  
Before And After

This paper empirically discovered the inter-linkages between stock and crude oil prices before and after the subprime financial crisis 2008 by using Johansan co-integration and Granger causality techniques to explore both long and short- run relationships.  The whole data set of Nifty index, Nifty energy index, BSE Sensex, BSE energy index and oil prices are divided into two periods; before crisis (from February 15, 2005 to December31, 2007) and after crisis (from January 1, 2008 to December 31, 2018) are collected and analyzed. The results discovered that there is one-way causal relationship from crude oil prices to Nifty index, Nifty energy index, BSE Sensex and BSE energy index but not other way around in both periods. However, a bidirectional causality relationship between BSE Energy index and crude oil prices during post subprime financial crisis 2008. The co-integration results suggested that the absence of long run relationship between crude oil prices and market indices of BSE Sensex, BSE energy index, Nifty index and Nifty energy index before and after subprime financial crisis 2008.

ИССЛЕДОВАНИЕ НИТРИД-ГАЛЛИЕВЫХ МАЛОШУМЯЩИХ УСИЛИТЕЛЕЙ ПРИ КРИОГЕННЫХ ТЕМПЕРАТУРАХ

2020 ◽  
Vol 96 (3s) ◽  
pp. 347-352
Author(s):  
Д.Г. Алипа ◽  
В.В. Краснов ◽  
В.М. Минненбаев ◽  
А.В. Редька ◽  
Ю.В. Федоров
Keyword(s):  
Remote Sensing ◽  
Gallium Nitride ◽  
Millimeter Wave ◽  
Low Noise ◽  
Low Noise Amplifiers ◽  
Cryogenic Temperatures ◽  
Space Systems ◽  
Earth Remote Sensing ◽  
Hydrogen Level

В статье представлены результаты исследования возможности применения при криогенных температурах водородного уровня дискретных приборов и монолитных схем на основе нитрида галлия в составе малошумящих усилителей сантиметрового и миллиметрового диапазона длин волн для приемных устройств систем дистанционного зондирования Земли из космоса и в составе криогенных комплексов наблюдения космического пространства. The article presents the results of the research on the possibility of using discrete devices and gallium nitride monolithic circuits at the cryogenic temperatures of hydrogen level as part of low-noise amplifiers of centimeter and millimeter-wave bands used in receivers of Earth remote sensing space systems and in cryogenic systems for space observation.

scholarly journals Visual Analysis of Biomarkers Reveals Differences in Lipid Profiles and Liver Enzymes before and after Gastric Sleeve and Bypass

Obesity Facts ◽  
2021 ◽  
pp. 1-11
Author(s):  
Marijn Marthe Georgine van Berckel ◽  
Saskia L.M. van Loon ◽  
Arjen-Kars Boer ◽  
Volkher Scharnhorst ◽  
Simon W. Nienhuijs
Keyword(s):  
Bariatric Surgery ◽  
Visual Analytics ◽  
Biochemical Markers ◽  
Visual Analysis ◽  
Large Population ◽  
High Volume ◽  
Cholesterol Concentration ◽  
Health State ◽  
Data Set ◽  
Before And After

<b><i>Introduction:</i></b> Bariatric surgery results in both intentional and unintentional metabolic changes. In a high-volume bariatric center, extensive laboratory panels are used to monitor these changes pre- and postoperatively. Consecutive measurements of relevant biochemical markers allow exploration of the health state of bariatric patients and comparison of different patient groups. <b><i>Objective:</i></b> The objective of this study is to compare biomarker distributions over time between 2 common bariatric procedures, i.e., sleeve gastrectomy (SG) and gastric bypass (RYGB), using visual analytics. <b><i>Methods:</i></b> Both pre- and postsurgical (6, 12, and 24 months) data of all patients who underwent primary bariatric surgery were collected retrospectively. The distribution and evolution of different biochemical markers were compared before and after surgery using asymmetric beanplots in order to evaluate the effect of primary SG and RYGB. A beanplot is an alternative to the boxplot that allows an easy and thorough visual comparison of univariate data. <b><i>Results:</i></b> In total, 1,237 patients (659 SG and 578 RYGB) were included. The sleeve and bypass groups were comparable in terms of age and the prevalence of comorbidities. The mean presurgical BMI and the percentage of males were higher in the sleeve group. The effect of surgery on lowering of glycated hemoglobin was similar for both surgery types. After RYGB surgery, the decrease in the cholesterol concentration was larger than after SG. The enzymatic activity of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphate in sleeve patients was higher presurgically but lower postsurgically compared to bypass values. <b><i>Conclusions:</i></b> Beanplots allow intuitive visualization of population distributions. Analysis of this large population-based data set using beanplots suggests comparable efficacies of both types of surgery in reducing diabetes. RYGB surgery reduced dyslipidemia more effectively than SG. The trend toward a larger decrease in liver enzyme activities following SG is a subject for further investigation.

352 Feasibility of Hypnosis as Adjunctive Treatment for Subjective Sleep Disturbance: A Pilot Study and Proof of Concept

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A140-A141
Author(s):  
Emma Zhao ◽  
Afik Faerman ◽  
David Spiegel
Keyword(s):  
Sleep Quality ◽  
Sleep Disturbances ◽  
Positive Impact ◽  
Self Report ◽  
Adjunctive Treatment ◽  
Current Evidence ◽  
Data Set ◽  
Sleep Complaints ◽  
Subjective Sleep ◽  
Before And After

Abstract Introduction Hypnosis-based interventions have been shown to have a positive impact on several dimensions of sleep health. However, current evidence is limited as only a paucity of studies included populations with sleep complaints. Here we present a pilot data set to demonstrate the feasibility of developing a hypnosis-based adjunctive treatment for subjective sleep complaints. Methods Eleven adults (42% female; mean age 45±16.87 years) who sought treatment at the Stanford Sleep Medicine Center or Center for Integrative Medicine for subjective sleep complaints received hypnosis as adjunctive treatment. Self-report questionnaires were used to assess the weekly frequency of subjective sleep disturbances experienced before and after treatment, as well as 5-point Likert scale ratings of perceived qualitative improvement in symptom severity and overall sleep quality. Results Five participants (45%) reported a reduction in symptom frequency and severity after hypnosis treatment. All five participants attributed at least some of the improvement to hypnosis treatment. Most participants (63%) observed post-treatment improvements in their overall sleep quality. No participants reported adverse effects of hypnosis. Conclusion Results suggest hypnosis-based adjunctive treatment may be effective for alleviating subjective sleep disturbances. The findings serve as preliminary support for further randomly controlled trials in larger samples. Support (if any):

III-V HEMTs for Cryogenic Low Noise Amplifiers

2020 ◽  
Author(s):  
J. Grahn ◽  
E. Cha ◽  
A. Pourkabirian ◽  
J. Stenarson ◽  
N. Wadefalk
Keyword(s):  
Low Noise ◽  
Low Noise Amplifiers

scholarly journals Measuring ice- and liquid-water properties in mixed-phase cloud layers at the Leipzig Cloudnet station

2016 ◽  
Vol 16 (16) ◽  
pp. 10609-10620 ◽  
Author(s):  
Johannes Bühl ◽  
Patric Seifert ◽  
Alexander Myagkov ◽  
Albert Ansmann
Keyword(s):  
Water Content ◽  
Liquid Water ◽  
Mass Flux ◽  
Mixed Phase ◽  
Cloud Base ◽  
Doppler Velocity ◽  
Special Focus ◽  
Data Set ◽  
Ice Water Content ◽  
Ice Water

Abstract. An analysis of the Cloudnet data set collected at Leipzig, Germany, with special focus on mixed-phase layered clouds is presented. We derive liquid- and ice-water content together with vertical motions of ice particles falling through cloud base. The ice mass flux is calculated by combining measurements of ice-water content and particle Doppler velocity. The efficiency of heterogeneous ice formation and its impact on cloud lifetime is estimated for different cloud-top temperatures by relating the ice mass flux and the liquid-water content at cloud top. Cloud radar measurements of polarization and Doppler velocity indicate that ice crystals formed in mixed-phase cloud layers with a geometrical thickness of less than 350 m are mostly pristine when they fall out of the cloud.

Sign in / Sign up

Export Citation Format

Share Document