scholarly journals STATISTICS OF VARIATION RANGE OF F2- LAYER MAXIMUM HEIGHT OF THE IONOSPHERE

Author(s):  
Arthur Fedorovich Yakovets ◽  
◽  
Arezu Jahanshir ◽  
Galina Ivanovna Gordienko ◽  
Beybit Tenelovich Zhumabayev ◽  
...  
2015 ◽  
Vol 55 (5) ◽  
pp. 609-622 ◽  
Author(s):  
V. N. Shubin ◽  
A. T. Karpachev ◽  
V. A. Telegin ◽  
K. G. Tsybulya

2011 ◽  
Vol 28 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Oto Hanuš ◽  
Václava Genčurová ◽  
Yunhai Zhang ◽  
Pavel Hering ◽  
Jaroslav Kopecký ◽  
...  

Milk acetone determination by the photometrical method after microdiffusion and via FT infra-red spectroscopyMilk acetone (AC) and betahydroxybutyrate (BHB) are important indicators of the energy metabolism of cows (ketosis occurrence) and an effective method for their determination, with reliable results, is of great importance. The goal of this work was to investigate the infrared method MIR-FT in terms of its calibration for milk AC and to develop a usable procedure. The microdiffusion photometric (485 nm; Spekol 11) method was used with salicylaldehyde as a reference (Re) and mid infrared spectroscopy FT (MIR-FT: Lactoscope FT-IR, Delta; MilkoScan FT 6000, M-Sc) as an indirect method. The acetone addition to milk had no recovery using MIR-FT (Delta). The reference AC set must have acceptable statistics for good MIR-FT calibration (M-Sc) and they were: 10.1 ± 9.74 at a geometric mean of 7.26 mg l-1, and a variation range from 1.98 to 33.66 mg l-1. The AC correlation between Re and MIR-FT (Delta) was low at 0.32 (P>0.05 but the Log AC relationship between Re and MIR-FT (M-Sc) was markedly better at 0.80 (P<0.01). The conversion of >10 mg l-1 as an AC subclinical ketosis limit could be > -0.80 (feedback 0.158 mmol l-1 = 9.25 mg l-1) and > -1.66. This could be important for ketosis monitoring (using M-Sc).


Author(s):  
Frank S. Levin

Surfing the Quantum World bridges the gap between in-depth textbooks and typical popular science books on quantum ideas and phenomena. Among its significant features is the description of a host of mind-bending phenomena, such as a quantum object being in two places at once or a certain minus sign being the most consequential in the universe. Much of its first part is historical, starting with the ancient Greeks and their concepts of light, and ending with the creation of quantum mechanics. The second part begins by applying quantum mechanics and its probability nature to a pedagogical system, the one-dimensional box, an analog of which is a musical-instrument string. This is followed by a gentle introduction to the fundamental principles of quantum theory, whose core concepts and symbolic representations are the foundation for most of the subsequent chapters. For instance, it is shown how quantum theory explains the properties of the hydrogen atom and, via quantum spin and Pauli’s Exclusion Principle, how it accounts for the structure of the periodic table. White dwarf and neutron stars are seen to be gigantic quantum objects, while the maximum height of mountains is shown to have a quantum basis. Among the many other topics considered are a variety of interference phenomena, those that display the wave properties of particles like electrons and photons, and even of large molecules. The book concludes with a wide-ranging discussion of interpretational and philosophic issues, introduced in Chapters 14 by entanglement and 15 by Schrödinger’s cat.


Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 204
Author(s):  
Shao-En Chen ◽  
Ray-Yeng Yang ◽  
Guang-Kai Wu ◽  
Chia-Che Wu

In this paper, a piezoelectric wave-energy converter (PWEC), consisting of a buoy, a frequency up-conversion mechanism, and a piezoelectric power-generator component, is developed. The frequency up-conversion mechanism consists of a gear train and geared-linkage mechanism, which converted lower frequencies of wave motion into higher frequencies of mechanical motion. The slider had a six-period displacement compared to the wave motion and was used to excite the piezoelectric power-generation component. Therefore, the operating frequency of the piezoelectric power-generation component was six times the frequency of the wave motion. The developed, flexible piezoelectric composite films of the generator component were used to generate electrical voltage. The piezoelectric film was composed of a copper/nickel foil as the substrate, lead–zirconium–titanium (PZT) material as the piezoelectric layer, and silver material as an upper-electrode layer. The sol-gel process was used to fabricate the PZT layer. The developed PWEC was tested in the wave flume at the Tainan Hydraulics Laboratory, Taiwan (THL). The maximum height and the minimum period were set to 100 mm and 1 s, respectively. The maximum voltage of the measured value was 2.8 V. The root-mean-square (RMS) voltage was 824 mV, which was measured through connection to an external 495 kΩ resistive load. The average electric power was 1.37 μW.


2021 ◽  
pp. 112067212110237
Author(s):  
Ilkay Kilic Muftuoglu ◽  
Ecem Onder Tokuc ◽  
V Levent Karabas

Purpose: To report outcomes of pars plana vitrectomy (PPV) combined with internal limiting membrane (ILM) stuffing technique in patients with optic disc pit associated maculopathy (ODP-M). Methods: Data including best-corrected visual acuity (BCVA), central macular thickness (CMT), foveal center point thickness (FCP), and maximum height of fluid (max_fluid) (intraretinal or subretinal) were collected from the medical records of the patients. Results: Six eyes of six patients with a mean age of 28.0 ± 17.68 years (range: 9–53 year) underwent PPV + ILM plug surgery. The mean follow-up duration was 25.62 ± 26.11 months (range: 11.80–78.00 month) duration. The mean BCVA increased from 1.25 ± 1.04 logMAR (20/355, Snellen equivalent) to 0.86 ± 1.09 logMAR (20/144, Snellen equivalent) at last follow-up ( p = 0.043). Compared to baseline, CMT, FCP, and max_fluid significantly decreased at all visits after the surgery ( p < 0.05 for all visits). At last follow-up, 66.6% of the eyes (four eyes) showed complete resolution of fluid at a mean of 5.25 ± 4.99 months (range: 1–12 months) after the surgery. Conclusion: PPV with ILM plug seemed to be an effective surgical technique in ODP-M. Studies with longer follow-up and higher number of patients are needed to confirm our results.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jian Zhang ◽  
Anil Can ◽  
Pui Man Rosalind Lai ◽  
Srinivasan Mukundan ◽  
Victor M. Castro ◽  
...  

AbstractMorphological factors of intracranial aneurysms and the surrounding vasculature could affect aneurysm rupture risk in a location specific manner. Our goal was to identify image-based morphological parameters that correlated with ruptured basilar tip aneurysms. Three-dimensional morphological parameters obtained from CT-angiography (CTA) or digital subtraction angiography (DSA) from 200 patients with basilar tip aneurysms diagnosed at the Brigham and Women’s Hospital and Massachusetts General Hospital between 1990 and 2016 were evaluated. We examined aneurysm wall irregularity, the presence of daughter domes, hypoplastic, aplastic or fetal PCoAs, vertebral dominance, maximum height, perpendicular height, width, neck diameter, aspect and size ratio, height/width ratio, and diameters and angles of surrounding parent and daughter vessels. Univariable and multivariable statistical analyses were performed to determine statistical significance. In multivariable analysis, presence of a daughter dome, aspect ratio, and larger flow angle were significantly associated with rupture status. We also introduced two new variables, diameter size ratio and parent-daughter angle ratio, which were both significantly inversely associated with ruptured basilar tip aneurysms. Notably, multivariable analyses also showed that larger diameter size ratio was associated with higher Hunt-Hess score while smaller flow angle was associated with higher Fisher grade. These easily measurable parameters, including a new parameter that is unlikely to be affected by the formation of the aneurysm, could aid in screening strategies in high-risk patients with basilar tip aneurysms. One should note, however, that the changes in parameters related to aneurysm morphology may be secondary to aneurysm rupture rather than causal.


Author(s):  
Mohamed Abdelkader Souissi ◽  
Achraf Ammar ◽  
Omar Trabelsi ◽  
Jordan M. Glenn ◽  
Omar Boukhris ◽  
...  

The purpose of the present study was to investigate which of two strategies, Video Feedback with Pedagogical Activity (VF-PA) or Video Feedback (VF), would be more beneficial for the remote error correction of the snatch weightlifting technique during the confinement period. Thirty-five school aged children with at least three months of weightlifting experience were randomized to one of three training conditions: VF-PA, VF or the Control group (CONT). Subjects underwent test sessions one week before (T0) and one day after (T1) a six-session training period and a retention test session a week later (T2). During each test session, the Kinovea version 0.8.15 software measured the kinematic parameters of the snatch performance. Following distance learning sessions (T1), the VF-PA improved various kinematic parameters (i.e., barbell horizontal displacements, maximum height, looping and symmetry) compared with T0 (p < 0.5; Cohen’s d = 0.58–1.1). Most of these improvements were maintained during the retention test (T2) (p<0.01, Cohen’s d = 1.2–1.3) when compared withT0. However, the VF group improved only twoparameters (i.e., barbell symmetry and horizontal displacement) at T1 (p < 0.05; Cohen’s d = 0.9), which were not maintained at T2. Better horizontal displacement and looping values were registered during the retention test in the VF-PA group compared with theCONT group (p < 0.05, Cohen’s d = 1.49–1.52). The present findings suggest combining video feedback with pedagogical activity during the pandemic induced online coaching or physical education to improve movement learning in school aged children.


Iraq ◽  
1996 ◽  
Vol 58 ◽  
pp. 79-87
Author(s):  
Arlette Roobaert

During the 1993 season of excavations at Tell Ahmar, three pieces of a life-size basalt statue were found in a pit dug into one of the large walls surrounding an Iron Age vaulted tomb (Fig. 1). The head, the tors o and the lower part fitted together perfectly. When correctly assembled, these three pieces formed the figure of a standing beardless man with clasped hands (Fig. 2a−b). Only the feet were missing. The maximum height of the reconstructed statue is 1.45m. It was clear from the damage to portions of its body that the statue had been deliberately broken in antiquity. Details, such as a large hole on the right side of the chest, a smaller one on the top of the head and, above all, the defacement of the head suggest that the statue may have actually been “killed”.All three pieces of the statue, which was carved out of a blue greyish basalt of medium texture, were found lying on their backs (Fig. 4). The head lay next to the lower part of the statue, but was buried in a slightly deeper position. The relative placement of these fragments seems to be a clear indication that the statue was not knocked down at this particular spot, but was brought to this location in separate pieces, perhaps with the deliberate intention of burying them.The head was cut off as if the statue had been decapitated. The torso was separated from the lower portion of the statue by an oblique cut that divided the figure just below the waist. The cut runs downwards from the back and continues underneath the clasped hands at the front, leaving the hands almost completely undamaged. The lower part of the statue seems to have been separated from the missing feet by a horizontal cut. This may indicate that the base of the statue was left in situ, probably because it was solidly set in the ground.


1932 ◽  
Vol 7 (1) ◽  
pp. 35-42 ◽  
Author(s):  
K. R. U. Todd

The purpose of this paper is to put on record the discovery of various sites, containing traces of prehistoric man, in the neighbourhood of Bombay.The area of greatest importance is that of Worli. It is a cotton milling suburb of Bombay, distant some 4 miles from the Fort, and is situated on low lying marshy ground and bounded to the West by a low steep hill having a maximum height of 100 ft. O.D., and consisting of igneous basalt overlying amygdaloidal trap with a dyke of F.W. strata between. This dyke contains fossils of marsh tortoises, frogs and plants resembling bulrushes. The basalt is capped with red earth which is decomposing trap, and contains nodules of agate and blocks of chert. West of the hill is the Arabian Sea. The northern extremity of this hill ends in a spur which juts out into the sea, and here is the fishing village of Koliwada, consisting of mud huts.


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