This paper describes the Magnetic Electron Ion Spectrometer (MagEIS) instruments aboard the RBSP spacecraft from an instrumentation and engineering point of view. There are four magnetic ...spectrometers aboard each of the two spacecraft, one low-energy unit (20–240 keV), two medium-energy units (80–1200 keV), and a high-energy unit (800–4800 keV). The high unit also contains a proton telescope (55 keV–20 MeV).
The magnetic spectrometers focus electrons within a selected energy pass band upon a focal plane of several silicon detectors where pulse-height analysis is used to determine if the energy of the incident electron is appropriate for the electron momentum selected by the magnet. Thus each event is a two-parameter analysis, an approach leading to a greatly reduced background.
The physics of these instruments are described in detail followed by the engineering implementation. The data outputs are described, and examples of the calibration results and early flight data presented.
The temperature dependency of kinetic parameters in p-PbTe and p-CdTe thin films formed on glass substrates has been investigated. The surface mobility of current carriers in PbTe films was computed ...as a function of temperature under the assumption of diffuse scattering of charge carriers. The mechanisms of intergranular current carrier transfer related with thermoelectronic emission are established. The role of surface scattering and intergranular boundaries in thin films of lead and cadmium tellurides is addressed.
We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes Magnetic Electron Ion Spectrometer (MagEIS) electron flux measurements. We provide a ...detailed description of the algorithm with illustrative examples from on‐orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X‐rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X‐rays primarily produce contamination in the lower energy MagEIS electron channels (∼30–500 keV) and in regions of geospace where multi‐MeV electrons are present. Inner zone protons produce contamination in all MagEIS energy channels at roughly L < 2.5. The background‐corrected MagEIS electron data produce a more accurate measurement of the electron radiation belts, as most earlier measurements suffer from unquantifiable and uncorrectable contamination in this harsh region of the near‐Earth space environment. These background‐corrected data will also be useful for spacecraft engineering purposes, providing ground truth for the near‐Earth electron environment and informing the next generation of spacecraft design models (e.g., AE9).
Key Points
MagEIS instrument can quantify and remove background contamination from electron measurements
Most earlier measurements suffer from unquantifiable and uncorrectable contamination
Two primary sources of contamination are found: inner zone protons and bremsstrahlung X‐rays generated by energetic electrons
A modified surface was obtained on wide-gap II-VI compounds. The methods of thermal annealing for cadmium chalcogenides and chemical etching for the first time obtained heterolayers of atypical ...hexagonal modification of α-ZnSe have been improved. AFM topograms of surface nanostructures have been investigated and comprehensive studies of optical and luminescent properties have been carried out. The emission spectra were determined in the photon energy range 1.4-3.6 eV and the important role of recombination processes in the formation of the A band in the edge region was established. The dominant role of quantum-dimensional processes in the formation of the obtained B band of intense radiation in a wide spectral region of the visible and ultraviolet ranges has been established.
The studies of In nanosystem formation on (100) surface of In
4
Se
3
were conducted applying analysis of STM data from 1 × 1µm
2
areas considering the distribution of image pixels' height depending ...on the In deposition degree and kinetics of root mean square, skewness, kurtosis parameters.
We have shown the possibility of highly-oriented 1D indium nanostructures' growth with the Volmer-Weber growth mode on In
4
Se
3
(100) surface applied as template. The optimal conditions to obtain the most oriented nano wire like nanostructures is thermal-induced Volmer-Weber growth in successive cycles of indium deposition - heating with activation of the solid state dewetting process.
Global myocardial work (GMW) is an emerging method to characterize left ventricle (LV) function with potential advantages over both ejection fraction and global longitudinal strain (GLS). We aimed to ...determine the feasibility and reproducibility for echocardiographic-derived GMW in a healthy pediatric population; establish normal reference values; and investigate the influence of age, gender, and other clinical factor on normal reference ranges. We prospectively enrolled 212 individuals (median age of 9 years; interquartile range, 6 to 12 years, 112 female). Global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE) were measured from LV pressure–strain loops. Quantification of GMW was performed using a GE Vivid E95 system and available software package (Echopac V.203, GE). The mean LV EF was 64 ± 3% with GLS of -21.3 ± 1.5%. GWI was 1688 ± 219 mmHg% with mean GWE of 96.5 ± 1.4%. The GCW was 1959 ± 207 mmHg%, and the mean GWW of 61.1 ± 30.9 mmHg%. No significant difference was found in MW indices across age group and gender (
p
> 0.05 for all). There were significant correlations between both GWI and GCW with GLS and systolic blood pressure (
p
< 0.001), but not with GWE and GWW. Linear regression model revealed that GWI and GCW were more closely correlated with systolic blood pressure than GLS. LV MW indices had good intra-observer and inter-observer reproducibility. This study establishes both the feasibility and reference ranges for non-invasive echocardiographic indices of GMW in healthy children. Myocardial work appears to be a complementary modality to assess LV performance in children.
Sb
2
Te
3
layered chalcogenide crystal's (0001) surface was applied for self-organizing of deposited indium nanostructures' arrays while solid state dewetting procedure. Sb
2
Te
3
samples were ...characterized by XRD, XPS, LEED and STM/STS. STM shows that shape and spatial arrangement of indium induced 0 D nanostructures are consistent with the surface lattice symmetry. The fractal analysis of STM images of the (0001) Sb
2
Te
3
and (0001) InSe surfaces, which are similar in symmetry, shows that distribution in size of indium nanostructures are almost the same under commensurate experimental conditions. The STS reveals correlation between indium coverage and quantity of DOS within energy gap of Sb
2
Te
3
.
The purpose of this study was to evaluate the push-out strength of two different adhesive cements (total etch and self-adhesive) for glass fiber post (GFP) cementation using two different techniques ...(microbrush and elongation tip) of cement application. In addition, this study evaluated the effect of total-etch conditioning before the use of a self-adhesive cement. Sixty premolar specimens with a single root canal were selected, endodontically treated, and shaped for GFP cementation. The specimens were randomly placed into one of six groups according to the cement and technique used: RelyX ARC (ARC): ARC + microbrush, ARC + elongation tip; RelyX Unicem (RU): RU + microbrush, RU + elongation tip; or RelyX Unicem + 37% phosphoric acid (RUE): RUE + microbrush, RUE + elongation tip. Each specimen root was cut perpendicular to the vertical axis yielding six 1.0-mm-thick sections. Push-out strength test was performed, followed by statistical analysis using three-way analysis of variance and the Games-Howell test (p<0.05). Statistically significant differences between the groups were found (p< 0.05). The cervical third of the roots had the highest mean push-out strength values, while the apical third had the lowest mean values regardless of the technique used. The elongation technique produced higher mean push-out strength values compared to the microbrush technique. The self-etch adhesive cement had the highest mean push-out strength value in all thirds. The addition of a conditioning step before the self-etch adhesive cementation appears to be effective in enhancing push-out strength with GFPs.
Formation of indium deposited coverage on (001) surface of InTe layered semiconductor crystal due to solid state dewetting process was studied by STM/STS in UHV. The initial surface was characterized ...by XPS, LEED and AFM. InTe has tetragonal crystal structure of the TlSe type (I4/mcm space group, lattice parameters a = 8.4414(6) Å, c = 7.1333(5) Å) determined by XRD. STM/STS show that the shape and arrangement 0 D indium induced nanostructures are powered by square surface lattice symmetry. The STS reveal correlation between indium coverage kinetics and increase in the quantity of DOS within the band gap of InTe.
Mitral valve prolapse (MVP) is the most common valvar dysfunction in children. There is emerging evidence that MVP is not always a benign entity, hence identification of underlying mechanisms is ...pertinent to clinical management. Our group previously identified a ventricular contraction abnormality named end-systolic basal eversion (ESBE) in adults that contributed to MVP. The aim of this study was to evaluate regional circumferential strain in pediatric patients with MVP and ESBE compared to normal controls. Left ventricular circumferential strain was assessed in 16 pediatric patients referred for clinical echocardiographic examination with MVP and ESBE (MVP group) and compared to age-gender-matched healthy subjects. ESBE has been previously described as late systolic bileaflet mitral valve prolapse, papillary traction, and concomitant late systolic outward movement of the basal inferior myocardium. The mean age of the MVP group was 13.8 ± 4.6 year and 75% were female. All patients with MVP and controls had qualitatively normal systolic cardiac function. The MVP group had significantly lower regional strain values for 11/16 of the segments including all 6 basal segments. Importantly, the basal inferior (− 17.02 ± 8.32% vs. − 26.10 ± 3.18, p = 0.001) and basal inferolateral (− 19.53 ± 9.76 vs. − 26.10 ± 3.18, p = 0.03) had the lowest strain values compared to the average of all other segments suggesting weaker contraction in the basal inferior segments. Pediatric patients with MVP and ESBE are subject to a similar left ventricular mechanical dysfunction previously described in adults. ESBE was evident by decreased basal circumferential strain values. These findings denoted weaker contraction which is believed to propagate the late systolic outward movement of the basal ventricular myocardium.
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