scholarly journals A new frontier in laboratory physics: magnetized electron–positron plasmas

2020 ◽  
Vol 86 (6) ◽  
Author(s):  
M. R. Stoneking ◽  
T. Sunn Pedersen ◽  
P. Helander ◽  
H. Chen ◽  
U. Hergenhahn ◽  
...  
Keyword(s):  
Debye Length ◽  
Experimental Studies ◽  
Large Degree ◽  
Intense Laser ◽  
Positron Source ◽  
Planning Stage ◽  
Electron Positron ◽  
New Frontier ◽  
The Difference ◽  
Under Construction

We describe here efforts to create and study magnetized electron–positron pair plasmas, the existence of which in astrophysical environments is well-established. Laboratory incarnations of such systems are becoming ever more possible due to novel approaches and techniques in plasma, beam and laser physics. Traditional magnetized plasmas studied to date, both in nature and in the laboratory, exhibit a host of different wave types, many of which are generically unstable and evolve into turbulence or violent instabilities. This complexity and the instability of these waves stem to a large degree from the difference in mass between the positively and the negatively charged species: the ions and the electrons. The mass symmetry of pair plasmas, on the other hand, results in unique behaviour, a topic that has been intensively studied theoretically and numerically for decades, but experimental studies are still in the early stages of development. A levitated dipole device is now under construction to study magnetized low-energy, short-Debye-length electron–positron plasmas; this experiment, as well as a stellarator device that is in the planning stage, will be fuelled by a reactor-based positron source and make use of state-of-the-art positron cooling and storage techniques. Relativistic pair plasmas with very different parameters will be created using pair production resulting from intense laser–matter interactions and will be confined in a high-field mirror configuration. We highlight the differences between and similarities among these approaches, and discuss the unique physics insights that can be gained by these studies.

scholarly journals Advances in Plant Disease Detection and Monitoring: From Traditional Assays to In-Field Diagnostics

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2129 ◽  
Author(s):  
Ilaria Buja ◽  
Erika Sabella ◽  
Anna Grazia Monteduro ◽  
Maria Serena Chiriacò ◽  
Luigi De Bellis ◽  
...  
Keyword(s):  
Emerging Diseases ◽  
Diagnostic Methods ◽  
Preventive Actions ◽  
Initial Symptoms ◽  
New Frontier ◽  
Information And Communication ◽  
Instruments And Techniques ◽  
The Difference ◽  
Asymptomatic Individuals

Human activities significantly contribute to worldwide spread of phytopathological adversities. Pathogen-related food losses are today responsible for a reduction in quantity and quality of yield and decrease value and financial returns. As a result, “early detection” in combination with “fast, accurate, and cheap” diagnostics have also become the new mantra in plant pathology, especially for emerging diseases or challenging pathogens that spread thanks to asymptomatic individuals with subtle initial symptoms but are then difficult to face. Furthermore, in a globalized market sensitive to epidemics, innovative tools suitable for field-use represent the new frontier with respect to diagnostic laboratories, ensuring that the instruments and techniques used are suitable for the operational contexts. In this framework, portable systems and interconnection with Internet of Things (IoT) play a pivotal role. Here we review innovative diagnostic methods based on nanotechnologies and new perspectives concerning information and communication technology (ICT) in agriculture, resulting in an improvement in agricultural and rural development and in the ability to revolutionize the concept of “preventive actions”, making the difference in fighting against phytopathogens, all over the world.

Two important bridges protected from earthquake by extremely big sliding pendulum isolators

2021 ◽  
Author(s):  
Agostino Marioni ◽  
Roberto Dalpedri ◽  
Marco Banfi ◽  
Carla Cai
Keyword(s):  
Load Capacity ◽  
Special Focus ◽  
South East Asia ◽  
Vertical Load ◽  
Test Results ◽  
Surface Type ◽  
Total Length ◽  
Padma River ◽  
The Difference ◽  
Under Construction

<p>The Padma Bridge is a multipurpose road-rail bridge across the Padma River currently under construction in Bangladesh and is one of the most important projects in the whole south east Asia with a total length of 6150 m. The maximum design vertical load reaches 98725 kN.</p><p>The Holtekamp Bridge is a steel road bridge with 2 main spans of 150 m and 2 lateral spans of 75 for a total length of 450 m. The bridge is isolated by use of sliding pendulum isolators having a maximum vertical load capacity at ULS of 54915 kN.</p><p>In both cases the isolators are double sliding surface type but with a different approach about the central articulation. The paper aims to put in evidence the difference in behaviour of the 2 types of pendulum, analysing both the theoretical approach and the test results with a special focus over the adopted solution for perform the test on a device which exceed the capacity of aby existing laboratory.</p>

Investigation of Regression-Based Effect Size Methods Developed in Single-Subject Studies

2021 ◽  
pp. 014544552110540
Author(s):  
Nihal Sen
Keyword(s):  
Effect Size ◽  
Experimental Studies ◽  
Single Subject ◽  
Single Subject Design ◽  
Data Set ◽  
Design Studies ◽  
Sample Data ◽  
The Difference ◽  
D Values ◽  
Effect Size Calculation

The purpose of this study is to provide a brief introduction to effect size calculation in single-subject design studies, including a description of nonparametric and regression-based effect sizes. We then focus the rest of the tutorial on common regression-based methods used to calculate effect size in single-subject experimental studies. We start by first describing the difference between five regression-based methods (Gorsuch, White et al., Center et al., Allison and Gorman, Huitema and McKean). This is followed by an example using the five regression-based effect size methods and a demonstration how these methods can be applied using a sample data set. In this way, the question of how the values obtained from different effect size methods differ was answered. The specific regression models used in these five regression-based methods and how these models can be obtained from the SPSS program were shown. R2 values obtained from these five methods were converted to Cohen’s d value and compared in this study. The d values obtained from the same data set were estimated as 0.003, 0.357, 2.180, 3.470, and 2.108 for the Allison and Gorman, Gorsuch, White et al., Center et al., as well as for Huitema and McKean methods, respectively. A brief description of selected statistical programs available to conduct regression-based methods was given.

scholarly journals Design And Experimental Studies Of Flexible Trailing Edge For Variable Camber Morphing Wing

2021 ◽  
Author(s):  
Ahmad T. Kalaji
Keyword(s):  
Experimental Data ◽  
Carbon Fiber ◽  
Deflection Angle ◽  
Experimental Studies ◽  
Morphing Wing ◽  
Trailing Edge ◽  
Wing Section ◽  
Rigid Constraint ◽  
The Difference

This thesis presents a flexible trailing edge mechanism capable of undergoing a change in camber for a wing section. The mechanism takes advantage of a rigid constraint between the ends of two flexible carbon fiber panels, which produces a deflection when there is a difference in length between the two panels. A prototype was designed and built and experimental data was collected for the deformation of the panels for different values of lengths and analyzed to find a function to describe the coefficients which form the polynomials describing the shape for each of the panels, based on the difference in length value. Deflection and deflection angle results were used to develop a controller which will calculate the required change in length based on a deflection or angle and a bottom panel length input.

scholarly journals The Influence of Water and Mineral Oil On Volumetric Losses in a Hydraulic Motor

2017 ◽  
Vol 24 (s1) ◽  
pp. 213-223 ◽  
Author(s):  
Pawel Śliwiński
Keyword(s):  
Mathematical Model ◽  
Rotational Speed ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Mineral Oil ◽  
Hydraulic Motor ◽  
Small Constant ◽  
Influence Of Water ◽  
The Difference ◽  
Lubricating Properties

Abstract In this paper volumetric losses in hydraulic motor supplied with water and mineral oil (two liquids having significantly different viscosity and lubricating properties) are described and compared. The experimental tests were conducted using an innovative hydraulic satellite motor, that is dedicated to work with different liquids, including water. The sources of leaks in this motor are also characterized and described. On this basis, a mathematical model of volumetric losses and model of effective rotational speed have been developed and presented. The results of calculation of volumetric losses according to the model are compared with the results of experiment. It was found that the difference is not more than 20%. Furthermore, it has been demonstrated that this model well describes in both the volumetric losses in the motor supplied with water and oil. Experimental studies have shown that the volumetric losses in the motor supplied with water are even three times greater than the volumetric losses in the motor supplied with oil. It has been shown, that in a small constant stream of water the speed of the motor is reduced even by half in comparison of speed of motor supplied with the same stream of oil.

Drilling and Production Platforms for Arctic Offshore Development

1984 ◽  
Vol 21 (02) ◽  
pp. 182-185
Author(s):  
Ben C. Gerwick
Keyword(s):  
Oil And Gas ◽  
Lightweight Concrete ◽  
The Arctic ◽  
Arctic Seas ◽  
Planning Stage ◽  
Small Areas ◽  
Wide Range ◽  
Under Construction ◽  
Offshore Development ◽  
Sand And Gravel

Rapidly expanding development is taking place in the Arctic and sub-Arctic seas of Alaska and Canada, driven by the discovery of immense resources of oil and gas and favorable geophysical conditions in adjoining areas. The Arctic regions are dominated by sea ice, from the central polar pack to the pressure ridges and rubble piles that form in the shear zone along the periphery. In the east, adjoining Labrador and Newfoundland, icebergs are encountered. Storm waves and surges during the summer, strong seismicity in certain areas, and weak and construction-difficult soils in many areas combine to make the design and construction of platforms abnormally difficult. Existing platforms for offshore exploration include sand and gravel islands in shallow-water areas, floating drillships accompanied by icebreakers, a concrete-caisson-retained island in the Canadian Beaufort Sea, and a converted VLCC, grounded on a prepared embankment and given additional protection by artificially constructed ice rubble. At the present time, two steel caissons, designed to be filled with sand after founding, and one floating drilling structure are under construction. In the design and planning stage are a number of new concepts for caissons, mostly constructed of prestressed lightweight concrete, designed to resist global forces in the range of 150 000 kips or more and local concentrated forces of 800 to 1000 psi over small areas. Prestressed lightweight concrete appears well suited to the demands of Arctic service. The towing, deployment, founding, and subsequent removal of exploratory platforms demands consideration of a wide variety of naval architectural aspects. One of the more critical areas facing designers is how to determine the forces and displacements caused by impact from a large ice floe or berg. The compliance of the structure and the hydrodynamic dissipation of kinetic energy need to be considered, as well as the crushing of the ice. The successful development of the Arctic demands consideration not only of a wide range of engineering and naval architectural aspects but also their integration with ecological, social, political and economic considerations.

Diesel engine performance at the intake of the hydrogen&air mixture

2021 ◽  
pp. 119-126
Author(s):  
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Internal Combustion Engines ◽  
Fuel Efficiency ◽  
Experimental Studies ◽  
Motor Fuel ◽  
Engine Performance ◽  
Calorific Value ◽  
Hydrocarbon Emissions ◽  
The Difference

The prospects of using hydrogen as a motor fuel are noted. The problems that arise when converting a diesel engine to run on hydrogen are considered. The features of the organization of the working process of enginesrunning on hydrogen are analyzed. A method of supplying a hydrogenair mixture to a diesel engine is investigated. To supply hydrogen to the engine cylinders, it is proposed to use the Leader4M installation developed by TechnoHill Club LLC (Moscow). Experimental studies of a stationary diesel engine of the D245.12 S type with the supply of hydrogen at the inlet obtained at this installation are carried out. At the maximum power mode, the supply of hydrogen from this installation to the inlet of the diesel engine under study was 0.9 % by weight (taking into account the difference in the calorific value of oil diesel fuel and hydrogen). Such a supply of hydrogen in the specified mode made it possible to increase the fuel efficiency of the diesel engine and reduce the smoke content of exhaust gases, carbon monoxide and unburned hydrocarbon emissions. Keywords internal combustion engines; diesel engine; diesel fuel; hydrogen; hydrogenair mixture; fuel efficiency; exhaust gas toxicity indicators

Лексическая неоднозначность в экспериментальных исследованиях: метаанализ

2020 ◽  
pp. 43-51
Author(s):  
Анжелика Дубасова
Keyword(s):  
Language Processing ◽  
Ambiguity Resolution ◽  
Experimental Studies ◽  
Lexical Ambiguity ◽  
Point Of View ◽  
Lexical Ambiguity Resolution ◽  
Ambiguous Words ◽  
Main Factors ◽  
The Difference ◽  
The Right

The article analyses experimental studies of lexical ambiguity (polysemy and homonymy). In total, 42 papers published between 1981 and 2017 were selected for analysis. Selected works were analyzed from the point of view of a) interaction of the main factors of lexical ambiguity resolution (meaning dominance and context), b) modularity/interactivity of language systems. The choice of these issues was caused by the fact that, despite a significant number of papers addressing them, a common theoretical model of lexical ambiguity resolution is still missing. The analysis concluded that none of the existing models could be chosen as the only true one. I believe that it is more promising to combine all models into one; in this case, we should not talk about “models” but about “algorithms” or “strategies”. This merge is compatible with the results of studies of hemispheric asymmetry, which showed that the right and left hemispheres differently process ambiguous words. This difference is projected on the difference between the two main points of view on language processing, interactive and modular. Also, as a result of the analysis, the properties of meaning dominance and context as the main factors influencing the perception of ambiguity are summarized, and the ways and possibilities of their interaction are determined. These factors can participate in the process of resolving ambiguity autonomously or together, with different functions, speed, and levels of perception.

CEPC Linac design

2019 ◽  
Vol 34 (13n14) ◽  
pp. 1940005 ◽  
Author(s):  
Cai Meng ◽  
Jingru Zhang ◽  
Xiaoping Li ◽  
Guoxi Pei ◽  
Dou Wang ◽  
...  
Keyword(s):  
Dynamic Simulation ◽  
Repetition Frequency ◽  
Positron Source ◽  
Electron Positron ◽  
Transport Line ◽  
Simulation Results ◽  
Positron Beams

The Circular Electron–Positron Collider (CEPC) is a 100-km ring [Formula: see text] collider for a Higgs factory. The injector of CEPC is composed of Linac and Booster. The Linac is a normal conducting S-band Linac with a frequency of 2860 MHz; it provides electron and positron beams at an energy of up to 10 GeV with 100 Hz repetition frequency of 100 Hz. The Linac design and dynamic simulation results are discussed in detail in this paper, including electron bunching system, positron source, electron bypass transport line, damping ring and main Linacs.

scholarly journals AMADEUS Experiment: Studies on Antikaon Interactions with Nucleons and Nuclei

2018 ◽  
Vol 46 ◽  
pp. 1860071
Author(s):  
J. Marton ◽  
K. Piscicchia
Keyword(s):  
Bound States ◽  
Experimental Studies ◽  
Drift Chamber ◽  
Kaonic Hydrogen ◽  
Nucleon Interaction ◽  
S Wave ◽  
Data Set ◽  
Electron Positron ◽  
Low Energies ◽  
Kloe Collaboration

The understanding of the low-energy strong interaction involving strangeness is a challenging topic due to resonances and predicted kaonic nuclear bound states. The K- nucleon interaction is strongly attractive at low energies verified in kaonic hydrogen studied in the SIDDHARTA experiment at the DA[Formula: see text]NE electron-positron collider of LNF-INFN (Frascati/Italy). Hyperon resonances like the elusive [Formula: see text] in the s-wave impose questions about its nature. According to theoretical studies it can be described as a dynamically generated resonance with two poles or a quasi-bound [Formula: see text]N state, which could lead to kaonic nuclear bound states (e.g. K-pp). An insight in many open facets of the antikaon interactions can be provided by the AMADEUS experiment at DA[Formula: see text]NE based on the analysis of the data collected in 2004/2005 by the KLOE collaboration, and of the dedicated data set collected in 2012 by AMADEUS in collaboration with KLOE. As a first step data from antikaon-induced reactions in the drift chamber of KLOE were analyzed and yielded new results on antikaon absorption on nuclei. Recent results of the experimental studies and an outlook to the future possibilities within AMADEUS are presented.

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