scholarly journals Avalanche danger forecast in little study territories using GIS

2021 ◽  
Author(s):  
N.V. Kondratyeva ◽  
I.Z. Shidugov
Keyword(s):  
Maximum Height ◽  
Snow Melting ◽  
Avalanche Danger

Methods for determining the zone of avalanche initiation using tools are proposed ArcGis 10.4.1. The process of creating a raster of the slope of heights and later on the territory itself for dividing them into existing gradations is described. Demonstrated the process of determining the area of avalanche foci and determining the boundaries of the avalanche collection. The areas of avalanche origination within the avalanche collection have been corrected. The method of creating a map of the exposure of slopes in order to identify the area of accumulation and drift of snow, its dynamics and characteristics of snow melting is shown. Based on this, it becomes possible to determine the maximum height of avalanche initiation and the range of the avalanche ejection.

Preliminary Results of Research on Snow and Avalanches in Czechoslovakia

1957 ◽  
Vol 3 (21) ◽  
pp. 72-77
Author(s):  
Miloš Vrba ◽  
Bedřich Urbánek
Keyword(s):  
Thermal Properties ◽  
Snow Cover ◽  
Penetration Resistance ◽  
Preliminary Results ◽  
Avalanche Danger

AbstractThis paper gives a brief account of the results so far obtained in research in Czechoslovakia on the crystallographic, stratigraphical and thermal properties of snow cover, and the use of these data in avalanche investigations. Avalanche danger is predicted by comparing the penetration resistance of snow layers, measured with a rammsonde, with resistance graphs of typical avalanche situations.

Surfing the Quantum World

2017 ◽  
Author(s):  
Frank S. Levin
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Musical Instrument ◽  
Popular Science ◽  
Quantum Spin ◽  
Exclusion Principle ◽  
Maximum Height ◽  
Core Concepts ◽  
The Many ◽  
The One

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.

scholarly journals A Piezoelectric Wave-Energy Converter Equipped with a Geared-Linkage-Based Frequency Up-Conversion Mechanism

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 204
Author(s):  
Shao-En Chen ◽  
Ray-Yeng Yang ◽  
Guang-Kai Wu ◽  
Chia-Che Wu
Keyword(s):  
Power Generation ◽  
Wave Energy ◽  
Wave Motion ◽  
Wave Energy Converter ◽  
Gear Train ◽  
Piezoelectric Composite ◽  
Maximum Height ◽  
Resistive Load ◽  
Linkage Mechanism ◽  
Energy Converter

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.

Management of optic disc pit-associated maculopathy: A case series from a tertiary referral center

2021 ◽  
pp. 112067212110237
Author(s):  
Ilkay Kilic Muftuoglu ◽  
Ecem Onder Tokuc ◽  
V Levent Karabas
Keyword(s):  
Optic Disc ◽  
Case Series ◽  
Internal Limiting Membrane ◽  
Maximum Height ◽  
Optic Disc Pit ◽  
Tertiary Referral Center ◽  
Number Of Patients ◽  
The Mean ◽  
Foveal Center

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.

scholarly journals Ionic Runoff as a Way to Determine the Degree of Karst Denudation (Case Study Jasov Plateau, Slovak Karst, Slovakia)

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1449
Author(s):  
Alena Gessert ◽  
Imrich Sládek ◽  
Veronika Straková ◽  
Mihály Braun ◽  
Enikő Heim ◽  
...  
Keyword(s):  
Heavy Rain ◽  
Similar Amount ◽  
Karst Water ◽  
Karst Spring ◽  
Snow Melting ◽  
Flow Rates ◽  
Karst Springs ◽  
Degree Of Protection ◽  
Episodic Events

Estimation of the catchment area of a karst spring is not possible in all areas for various reasons. The Slovak Karst is protected by the highest degree of protection and karst springs are used as a source of drinking water for the second largest city in Slovakia, Košice. From this reason, no results on ionic runoff or chemical denudation have been published from this area and the most appropriate way to obtain information about the denudation rate is to determine the ionic runoff. This paper provides an overview of ionic runoff results based on sampling and analysis of karst water from six springs in the period November 2013–October 2016 (three hydrological years) and periodic measurements. Springs have significantly fluctuated flow rates from 0 L/s in summer and autumn up to 192 L/s, and episodic events during the snow melting and heavy rain in the spring of 2013 are also known (more than 380 L/s). The total value of ionic runoff for the area of 40,847 m3/y.km2 is comparable with the Vracanska Plateau in Bulgaria, which lies at a similar altitude and with a similar amount of precipitation.

scholarly journals Carbon Nanomaterials for Enhancing the Thermal, Physical and Rheological Properties of Asphalt Binders

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2585
Author(s):  
Zhelun Li ◽  
Xin Yu ◽  
Yangshi Liang ◽  
Shaopeng Wu
Keyword(s):  
High Temperature ◽  
Rheological Properties ◽  
Carbon Nanomaterials ◽  
Asphalt Binders ◽  
Snow Melting ◽  
Temperature Performance ◽  
Unique Nature ◽  
Application Potential ◽  
Urban Heat ◽  
Two Parameters

Effective thermal conduction modification in asphalt binders is beneficial to reducing pavement surface temperature and relieving the urban heat island (UHI) effect in the utilization of solar harvesting and snow melting pavements. This study investigated the performance of two nanometer-sized modifiers, graphene (Gr) and carbon nanotubes (CNTs), on enhancing the thermal, physical and rheological properties of asphalt binders. Measurements depending on a transient plant source method proved that both Gr and CNTs linearly increased the thermal conductivity and thermal diffusivity of asphalt binders, and while 5% Gr by volume of matrix asphalt contributed to 300% increments, 5% CNTs increased the two parameters of asphalt binders by nearly 72% at 20 °C. Meanwhile, a series of empirical and rheological properties experiments were conducted. The results demonstrated the temperature susceptibility reduction and high-temperature properties promotion of asphalt binders by adding Gr or CNTs. The variation trends in the anti-cracking properties of asphalt binders modified by Gr and CNTs with the modifier content differed at low temperatures, which may be due to the unique nature of Gr. In conclusion, Gr, whose optimal content is 3% by volume of matrix asphalt, provides superior application potential for solar harvesting and snow melting pavements in comparison to CNTs due to its comprehensive contributions to thermal properties, construction feasibility, high-temperature performance and low-temperature performance of asphalt binders.

scholarly journals Morphological variables associated with ruptured basilar tip aneurysms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jian Zhang ◽  
Anil Can ◽  
Pui Man Rosalind Lai ◽  
Srinivasan Mukundan ◽  
Victor M. Castro ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Multivariable Analysis ◽  
Aneurysm Rupture ◽  
Size Ratio ◽  
Width Ratio ◽  
Maximum Height ◽  
Morphological Parameters ◽  
Flow Angle ◽  
Aneurysm Wall ◽  
Fisher Grade

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.

scholarly journals Distance Motor Learning during the COVID-19 Induced Confinement: Video Feedback with a Pedagogical Activity Improves the Snatch Technique in Young Athletes

2021 ◽  
Vol 18 (6) ◽  
pp. 3069
Author(s):  
Mohamed Abdelkader Souissi ◽  
Achraf Ammar ◽  
Omar Trabelsi ◽  
Jordan M. Glenn ◽  
Omar Boukhris ◽  
...  
Keyword(s):  
Retention Test ◽  
Horizontal Displacement ◽  
Test Session ◽  
Video Feedback ◽  
Control Group ◽  
Maximum Height ◽  
Kinematic Parameters ◽  
School Aged Children ◽  
Cohen’S D ◽  
Cohen's D

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.

A Neo-Assyrian statue from Til Barsib

Iraq ◽  
1996 ◽  
Vol 58 ◽  
pp. 79-87
Author(s):  
Arlette Roobaert
Keyword(s):  
Iron Age ◽  
Lower Portion ◽  
Maximum Height ◽  
Clear Indication ◽  
Large Hole ◽  
Relative Placement ◽  
The Right ◽  
As If ◽  
Medium Texture

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.

Study on the Dynamics on the Brake of Vehicle after the Effects of Deicing Salt

2010 ◽  
Vol 26-28 ◽  
pp. 862-869
Author(s):  
Tao Peng ◽  
Zhi Peng Li ◽  
Chang Shu Zhan ◽  
Xiang Luo ◽  
Qian Wang
Keyword(s):  
Simulation Model ◽  
Dynamic Model ◽  
The Other ◽  
Snow Melting ◽  
Adhesion Coefficient ◽  
Deicing Salt ◽  
Other Hand ◽  
Road Condition ◽  
Braking Distance ◽  
The Relationship

Through analyzing the process of brake, a dynamic model of automobile and a model of the relationship between braking distance and adhesion coefficient were formed; also a simulation calculating model of braking distance was established with the use of Matlab. Finally, a research was done toward the braking distance of a type of a car running on a road after using snow-melting agent. On one hand, with the application of the simulation model which has been established, calculations have been done to the braking distance of Bora vehicles running on roads after using deicing salt; on the other hand, by experiments, Bora vehicles’ braking distance and maximum braking deceleration under the same road condition were measured, meanwhile, the established simulation model was verified.

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