Explore the vast range of titles available.

\"Orogenesis, the process of mountain building, occurs when two tectonic plates collide--either forcing material upwards to form mountain belts such as the Alps or Himalayas or causing one plate to be subducted below the other, resulting in volcanic mountain chains such as the Andes. Integrating the approaches of structural geology and metamorphism, this book provides an up-to-date overview of orogenic research, and an introduction to the physico-chemical properties of mountain belts. Global examples are explored, the interactioning roles of temperature and deformation in the orogenic process are reviewed, and important new concepts such as channel flow are explained. This book provides a valuable introduction to this fast-moving field for advanced undergraduate and graduate students of structural geology, plate tectonics and geodynamics, and will also provide a vital overview of research for academics and researchers working in related fields including petrology, geochemistry and sedimentology.\"-- Provided by publisher.

Deep penetration of outer radiation belt electrons to low L (<3.5) has long been recognized as an energy‐dependent phenomenon but with limited understanding. The Van Allen Probes measurements have clearly shown energy‐dependent electron penetration during geomagnetically active times, with lower energy electrons penetrating to lower L. This study aims to improve our ability to model this phenomenon by quantitatively considering radial transport due to large‐scale azimuthal electric fields (E‐fields) as an energy‐dependent convection term added to a radial diffusion Fokker‐Planck equation. We use a modified Volland‐Stern model to represent the enhanced convection field at lower L to match the observations of storm time values of E‐field. We model 10–400 MeV/G electron phase space density with an energy‐dependent radial diffusion coefficient and this convection term and show that the model reproduces the observed deep penetrations well, suggesting that time‐variant azimuthal E‐fields contribute preferentially to the deep penetration of lower‐energy electrons. Plain Language Summary Electrons trapped by the Earth's magnetic field gather in two regions known as the Van Allen radiation belts. It is well reported that electrons can be transported radially inward from the outer radiation belt during geomagnetically active times. More specifically, low energy (100 s of keV) electrons can be moved radially deeper than higher energy (∼1 MeV) electrons. Previous studies suggested that enhanced convection electric fields could contribute to the earthward transport of low energy (<200 keV) electrons. However, the mechanism which leads to different efficiencies of electron transport at different energies has not been quantified. This study expands the traditional radial diffusion model with an empirically determined convection term and shows that the net convection velocity increases for lower energy electrons. For the first time, we quantitatively modeled the energy‐dependent penetration of radiation belt electrons in a wide energy range (10 s of keV to 2 MeV) in the presence of enhanced large‐scale electric fields, during two geomagnetic storm events observed by the Van Allen Probes mission. Key Points Convective radial transport of storm‐time enhanced large‐scale E‐fields is an efficient inward transport mechanism of 10–100 s keV electrons The energy‐dependent electron penetration can be explained by the relation between the timescales of electron drift and large‐scale E‐fields A radial diffusion‐convection model is developed to reproduce the storm‐time penetration of lower energy electrons to lower L

Abrasive belt condition (BC) monitoring is significant for achieving profile finishing precision and quality in grinding of difficult-to-machine materials like Inconel 718. While indirect signal-based BC monitoring methods are ineffective when varying grinding parameters, existing image-based direct monitoring methods currently suffer from a lack of: (i) a unified and quantitative definition of the belt condition; (ii) in situ tool-surface image capture and relevant feature extraction; and (iii) continuous monitoring of the entire belt conditions. This paper proposes a partitioned BC monitoring method that is adaptable to ever-changing grinding conditions. Based on the belt surface analysis, a unified BC coefficient is quantitatively defined by using two critical BC-dependent features, the average area and number of worn flats of abrasive grains per unit area. The belt surface image is in-situ captured from moving belts and is preprocessed to eliminate image defects in a unified form, then the entire belt is partitioned, and finally the image features are extracted by Gabor filter and K-means clustering. The proposed robust method which has a maximum relative repeatability error of 9.33%, and less computation was validated by the experimental results. This study provides an adaptable and efficient way for continuously monitoring the conditions of the entire belt and the grinding area.

The Exploration of energization and Radiation in Geospace (ERG) project explores the acceleration, transport, and loss of relativistic electrons in the radiation belts and the dynamics for geospace storms. This project consists of three research teams for satellite observation, ground-based network observation, and integrated data analysis/simulation. This synergetic approach is essential for obtaining a comprehensive understanding of the relativistic electron generation/loss processes of the radiation belts as well as geospace storms through cross-energy/cross-regional couplings, in which different plasma/particle populations and regions are strongly coupled with each other. This paper gives an overview of the ERG project and presents the initial results from the ERG (Arase) satellite.

The article presents the potential impact of flat drive and transport belts on people’s safety during a fire. The analysis distinguished belts made of classically used fabric–rubber composite materials reinforced with cord and currently used multilayer polymer composites. Moreover, the products’ multilayers during the thermal decomposition and combustion can be a source of emissions for unpredictable and toxic substances with different concentrations and compositions. In the evaluation of the compared belts, a testing methodology was used to determine the toxicometric indicators (WLC50SM) on the basis of which it was possible to determine the toxicity of thermal decomposition and combustion products in agreement with the standards in force in several countries of the EU and Russia. The analysis was carried out on the basis of the registration of emissions of chemical compounds during the thermal decomposition and combustion of polymer materials at three different temperatures. Moreover, the degradation kinetics of the polymeric belts by using the thermogravimetric (TGA) technique was evaluated. Test results have shown that products of thermal decomposition resulting from the neoprene (NE22), leder leder (LL2), thermoplastic connection (TC), and extra high top cower (XH) belts can be characterized as moderately toxic or toxic. Their toxicity significantly increases with the increasing temperature of thermal decomposition or combustion, especially above 450 °C. The results showed that the belts made of several layers of polyamide can be considered the least toxic in fire conditions. The TGA results showed that NBR/PA/PA/NBR belt made with two layers of polyamide and the acrylonitrile–butadiene rubber has the highest thermal stability in comparison to other belts.

George Washington Carver (ca. 1864-1943) is at once one of the most familiar and misunderstood figures in American history. In My Work Is That of Conservation, Mark D. Hersey reveals the life and work of this fascinating man who is widely-and reductively-known as the African American scientist who developed a wide variety of uses for the peanut. Carver had a truly prolific career dedicated to studying the ways in which people ought to interact with the natural world, yet much of his work has been largely forgotten. Hersey rectifies this by tracing the evolution of Carver's agricultural and environmental thought starting with his childhood in Missouri and Kansas and his education at the Iowa Agricultural College. Carver's environmental vision came into focus when he moved to the Tuskegee Institute in Macon County, Alabama, where his sensibilities and training collided with the denuded agrosystems, deep poverty, and institutional racism of the Black Belt. It was there that Carver realized his most profound agricultural thinking, as his efforts to improve the lot of the area's poorest farmers forced him to adjust his conception of scientific agriculture. Hersey shows that in the hands of pioneers like Carver, Progressive Era agronomy was actually considerably \"greener\" than is often thought today. My Work Is That of Conservation uses Carver's life story to explore aspects of southern environmental history and to place this important scientist within the early conservation movement.

Electromagnetic ion cyclotron waves in the Earth's outer radiation belt drive rapid electron losses through wave‐particle interactions. The precipitating electron flux can be high in the hundreds of keV energy range, well below the typical minimum resonance energy. One of the proposed explanations relies on nonresonant scattering, which causes pitch‐angle diffusion away from the fundamental cyclotron resonance. Here we propose the fractional sub‐cyclotron resonance, a second‐order nonlinear effect that scatters particles at resonance order n = 1/2, as an alternate explanation. Using test‐particle simulations, we evaluate the precipitation ratios of sub‐MeV electrons for wave packets with various shapes, amplitudes, and wave normal angles. We show that the nonlinear sub‐cyclotron scattering produces larger ratios than the nonresonant scattering when the wave amplitude reaches sufficiently large values. The ELFIN CubeSats detected several events with precipitation ratio patterns matching our simulation, demonstrating the importance of sub‐cyclotron resonances during intense precipitation events. Plain Language Summary High‐energy electrons in the Earth's radiation belt are constantly being scattered by the ubiquitous electromagnetic plasma waves. A portion of these scattered electrons is lost to the atmosphere, where the particles deposit their energy and cause a chain of chemical reactions, possibly contributing to ozone destruction. The energy and flux of the precipitating electrons depend on the nature of the wave‐particle interactions in the radiation belt. The electromagnetic ion cyclotron wave (EMIC), known to be responsible for scattering relativistic electrons, has been observed to cause precipitation at energies much lower than expected by the standard theory. We numerically investigate two types of interactions, the nonresonant scattering and the nonlinear sub‐cyclotron scattering, and show how both influence the relative precipitating fluxes. We demonstrate that sub‐cyclotron interactions driven by intense EMIC waves can cause stronger precipitation than nonresonant scattering at sub‐MeV energies. The dual ELFIN CubeSats detected precipitation profiles that match our numerical results, confirming the importance of nonlinear sub‐cyclotron scattering in the analysis of intense precipitation events. Key Points Electrons resonate with intense quasiparallel electromagnetic ion cyclotron wave waves at fractions of the minimum resonance energy Fractional resonant scattering causes significant precipitation when the wave amplitude reaches above 1% of the ambient field Precipitating electron flux spectrum observed by the ELFIN CubeSats supports the estimated influence of fractional resonances

Wave-particle interactions play a fundamental role in the dynamic variability of Earth’s donut-shaped radiation belts that are highly populated by magnetically trapped energetic particles and characteristically separated by the slot devoid of high energetic electrons. Owing to the continuous accumulation of high-quality wave and particle measurements from multiple satellites in geospace, the important contribution of ground-based very-low-frequency (VLF) transmitter waves to the electron dynamics in the near-Earth space has been unprecedently advanced, in addition to those established findings of the significant effects of a variety of naturally occurring magnetospheric waves. This paper focuses on the artificial modification of Earth’s inner radiation belt and slot by artificial VLF transmitter emissions. We review the global distributions of VLF transmitter waves in geospace, their scattering effects on radiation belt electrons in terms of both theoretical and observational analyses, and diffusion simulation results of wave-particle interactions along with data-model comparisons. We start with a brief review of the radiation belt electron dynamics and an introduction of anthropogenic VLF transmitter waves. Subsequently, we review the global morphology of in situ VLF transmitter waves corresponding to different transmitter locations, including their day-night asymmetry, geographic distributions, seasonal and geomagnetic activity dependence, and wave propagation features. Existed theoretical and observational analyses of electron scattering effects by VLF transmitter waves are then reviewed to approach the underlying physics that can modulate the spatio-temporal variations of the electron radiation belts. Further Fokker-Planck electron diffusion simulations and their comparisons with realistic satellite observations clearly indicate that VLF transmitter emissions can effectively remove energetic electrons to produce a radially bifurcated electron belt, thereby quantitatively confirming the direct link between operations of VLF transmitters at ground and changes of the energetic electron environment in space. We finally discuss the unsolved problems and possible future research in this area, which has important implications for potential mitigation of the natural particle radiation environment with active means.

Belt conveyors are used for the transportation of bulk materials in a number of different branches of industry, especially in mining and power industries or in shipping ports. The main component of a belt conveyor is its belt, which serves both as a support for the transported material along the conveyor route and as an element in the drive transmission system. Being crucial to the effective and reliable operation of the conveyor, the belt is also its most expensive and the least durable element. A conveyor belt comprises a core, covers and edges. A multiply textile belt, in which the core is constructed of synthetic fibers such as polyamide, polyester or aramid, is the oldest and still the most commonly used conveyor belt type. The plies are joined with a thin layer of rubber or another material (usually the material is the same as the material used in the covers), which provides the required delamination strength to the belt and allows the plies to move relative to each other as the belt is bent. Belts are installed on the conveyors in a closed loop in order to join belt sections, whose number and length depend on the length and type of the belt conveyor. Belts are joined with each other in a splicing procedure. The cutting of the belt core causes belt splices to be prone to concentrated stresses. The discontinued core also causes the belt to be the weakest element in a conveyor belt loop. The article presents the results of strength parameter tests that were performed on laboratory and industrial splices and indicated the reasons for the reduced strength of conveyor belt splices. Splice strength is reduced mainly due to incorrect preparation of the spliced surfaces and to different mechanical parameters of the spliced belts.