Shock-produced mosaicism in plagioclase, Charlevoix structure, Quebec

1977 ◽  
Vol 14 (1) ◽  
pp. 74-81 ◽  
Author(s):  
Michael J. Walawender
Keyword(s):  
Impact Crater ◽  
Morphological Character ◽  
Shock Metamorphism ◽  
Complex Nature ◽  
Impact Event ◽  
X Ray ◽  
Shock Process ◽  
Wide Range ◽  
Differential Uplift ◽  
The Impact

The Charlevoix structure, Quebec, Canada, is generally accepted as a Paleozoic meteorite impact site. Plagioclase grains from samples in and around this structure were examined via X-ray (oscillation) techniques to determine the maximum range of angular misorientation between crystal subdomains (mosaicism) within a given sample (ηmax), and its usefulness as an index of shock metamorphism at Charlevoix. The complex morphological character of the impact crater can be divided into five concentric zones, which exhibit alternately high and low values of ηmax. This distribution appears to be the result of differential uplift and subsidence that followed the impact event, in that blocks which have undergone different shock histories during the impact event have been brought into juxtaposition. The wide range in ηmax within as well as between samples attests to the complex nature of the shock process and the hazards of using mosaicism as the sole index of shock metamorphism.

scholarly journals The Public Health Implications of Brexit: A Health Impact Assessment Approach

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
L Green
Keyword(s):  
Public Health ◽  
Impact Assessment ◽  
Health Impact Assessment ◽  
Health Impact ◽  
Complex Nature ◽  
The Public ◽  
Wide Range ◽  
The Impact ◽  
The Eu ◽  
Public Bodies

Abstract On March 29th 2019, the United Kingdom (UK) was due to exit the EU in a process known informally as ’Brexit’. This exit and entry into a 2-year transition is a period of unprecedented political and social upheaval - with many unknowns and much uncertainty attached to the outcomes and future impact. In preparation for Brexit, Public Health Wales commissioned the Wales HIA Support Unit to carry out a health impact assessment of Brexit in Wales to support and inform its and other public bodies planning and future work. This paper examines the unique HIA carried out between July and December 2018 on the impact of the UK withdrawal from the EU in Wales. It discusses the robust, participatory process undertaken, the stakeholders involved and the benefits reaped from this. It highlights the evidence gathered and analysed including the collection methods, the complex nature of the work and disseminates the main findings from the HIA including the potential determinants of health and population groups identified. Finally, it describes the challenges faced, how these were overcome, and the huge benefits, impact and influence it has had to date across a wide range of UK and Welsh organisations and public bodies. This work demonstrates continued leadership in the field of impact assessment and spearheads the requirement for public bodies to carry out HIAs as part of the forthcoming statutory requirements of the Public Health (Wales) Act 2017 an can inform practice at a global level. Key messages HIA can inform and influence action in response to important strategic decisions. The Brexit HIA is a unique example which can inform international HIA practice.

Impact of X-ray induced radiation damage on FD-MAPS of the ARCADIA project

2022 ◽  
Vol 17 (01) ◽  
pp. C01035
Author(s):  
C. Neubüser ◽  
T. Corradino ◽  
S. Mattiazzo ◽  
L. Pancheri
Keyword(s):  
Power Consumption ◽  
Radiation Damage ◽  
High Energy ◽  
Full Potential ◽  
Sensor Design ◽  
Charge Collection Efficiency ◽  
X Ray ◽  
Active Pixel ◽  
Wide Range ◽  
The Impact

Abstract Recent advancements in Monolithic Active Pixel Sensors (MAPS) demonstrated the ability to operate in high radiation environments of up to multiple kGy’s, which increased their appeal as sensors for high-energy physics detectors. The most recent example in such application is the new ALICE inner tracking system, entirely instrumented with CMOS MAPS, that covers an area of about 10 m2. However, the full potential of such devices has not yet been fully exploited, especially in respect of the size of the active area, power consumption, and timing capabilities. The ARCADIA project is developing Fully Depleted (FD) MAPS with an innovative sensor design, that uses a proprietary processing of the backside to improve the charge collection efficiency and timing over a wide range of operational and environmental conditions. The innovative sensor design targets very low power consumption, of the order of 20 mW cm−2 at 100 MHz cm−2 hit flux, to enable air-cooled operations of the sensors. Another key design parameter is the ability to further reduce the power regime of the sensor, down to 5 mW cm−2 or better, for low hit rates like e.g. expected in space experiments. In this contribution, we present a comparison between the detector characteristics predicted with Technology Computer Aided Design (TCAD) simulations and the ones measured experimentally. The comparison focuses on the current-voltage (IV) and capacitance-voltage (CV) characteristics, as well as noise estimated from in-pixel capacitances of passive/active pixel matrices. In view of the targeted applications of this technology, an emphasis is set on the modeling of X-ray induced radiation damage at the Si-SiO2 interface and the impact on the in-pixel sensor capacitance. The so-called new Perugia model has been used in the simulations to predict the sensor performance after total ionizing doses of up to 10 Mrad.

Theoretical and Experimental X-Ray Peak/Background Ratios and Implications for Energy-Dispersive Spectrometry in the Next-Generation Analytical Electron Microscope

2016 ◽  
Vol 22 (1) ◽  
pp. 230-236 ◽  
Author(s):  
Nestor J. Zaluzec
Keyword(s):  
Theoretical Calculations ◽  
Detection Sensitivity ◽  
X Ray ◽  
Background Ratio ◽  
Exit Surface ◽  
Wide Range ◽  
Analytical Electron ◽  
Solid Angles ◽  
Electron Microscopes ◽  
The Impact

AbstractModern analytical electron microscopes equipped with silicon drift detectors now allow for a wide range of geometrical configurations capable of performing quantitative X-ray spectrometry. Recent work has improved the collection solid angles of these detectors, however, the impact of increasing the solid angle on detection sensitivity as measured by the peak/background ratio has not been addressed. This work compares theoretical and experimental peak/background ratios for incident electron energies in the range of 20–200 keV, with X-ray detectors in both conventional orientations (on the electron entrance surface) as well as new geometries (the electron exit surface). The implications of these parameters on detectability limits for the next generations of “Lab-in-the-Gap” analytical microscope are also considered. It was found that theoretical calculations of the angular distribution of bremsstrahlung and their effects on the peak/background ratio match well with experimental measurements, and indicate that new geometries which can result in large solid angles provided an added benefit in addition to increased characteristic signal, namely increased sensitivity for the analyst.

scholarly journals Dynamics of cavitation zone development during sonication of suspensions of magnesium particles

2021 ◽  
pp. 75-84
Author(s):  
Надежда Юрьевна Брежнева ◽  
Вячеслав Сергеевич Минчук ◽  
Светлана Александровна Уласевич ◽  
Николай Васильевич Дежкунов ◽  
Екатерина Владимировна Скорб
Keyword(s):  
Ultrasonic Treatment ◽  
Chemical Interaction ◽  
Complex Nature ◽  
X Ray ◽  
Wide Range ◽  
Zone Development ◽  
Constant Output ◽  
Cavitation Activity ◽  
Hydride Phases ◽  
Activity Dynamics

The cavitation activity during ultrasonic treatment of magnesium particles has been investigated. The cavitation activity recorded in a continuous mode of ultrasonic treatment altered in a wide range at constant output parameters of the generator. The rate and nature of cavitation activity variation depended on the mass fraction of particles in the suspension. It has been demonstrated that during the ultrasonic treatment of magnesium aqueous suspensions it is possible to determine the following stages: growth of cavitation activity, reaching a maximum followed by a decrease and reaching a plateau (or repeated cycles of increasing or decreasing cavitation activity). The complex nature of the cavitation activity dynamics is associated with the participation of hydrogen released as a result of the chemical interaction of magnesium particles with water in the formation of the cavitation zone. The magnesium particles modified with ultrasound were characterised with the use of scanning electron microscopy, X-ray phase analysis and thermal analysis. It has been found that ultrasonic treatment of magnesium particles resulted in the formation of magnesium hydroxide and magnesium hydride phases.

scholarly journals Nikola Tesla and medicine: 160th anniversary of the birth of the genius who gave light to the world - part I

2016 ◽  
Vol 69 (9-10) ◽  
pp. 313-322
Author(s):  
Danijela Vucevic ◽  
Drago Djordjevic ◽  
Tatjana Radosavljevic
Keyword(s):  
High Frequency ◽  
X Rays ◽  
X Ray ◽  
Nikola Tesla ◽  
Wide Range ◽  
The World ◽  
Biologic Effects ◽  
History Of ◽  
The Impact ◽  
Harmful Effects

Introduction. The interest in Nikola Tesla, a scientist, physicist, engineer and inventor, is constantly growing. In the millennia-long history of human civilization, it is almost impossible to find another person whose life and work has been under so much scrutiny of such a wide range of researchers, medical professionals included. Although Tesla was not primarily dedicated to biomedical research, his work significantly contributed to the development of radiology, and high frequency electrotherapy. This paper deals with the impact of Tesla?s work on the development of a new medical branch - radiology. Nikola Tesla and the Discovery of X-ray radiation. Tesla pioneered the use of X-rays for medical purposes, practically laying the foundations of radiology. Namely, since 1887, Tesla periodically experimented with X-rays, at that time still unknown and unnamed, which he called "shadowgraphs". Moreover, at the end of 1894, he conducted extensive research focusing on X-rays, but unfortunately it was interrupted after the fire burning down his laboratory in 1895. In 1896 and 1897, Tesla published ten papers on the biologic effects of X-ray radiation. All his studies on X-rays were experimental. During 1896 and 1897, Tesla continued improving X-ray devices. Apart from this, Tesla was the first to point out the harmful effects of exposure to X-ray radiation on human body. Conclusion. Nikola Tesla was a visionary genius of the future. Tesla?s pioneer steps, made more than a century ago in the domain of radiology, are still being used today.

scholarly journals Properties of Impact-Related Pseudotachylite and Associated Shocked Zircon and Monazite in the Upper Levels of a Large Impact Basin: a Case Study From the Vredefort Impact Structure

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1053
Author(s):  
Elizaveta Kovaleva ◽  
Roger Dixon
Keyword(s):  
Impact Crater ◽  
Shock Pressure ◽  
Initial Structure ◽  
Impact Structure ◽  
Near Surface ◽  
X Ray ◽  
Host Rocks ◽  
The Impact

The Vredefort impact structure in South Africa is deeply eroded to its lowermost levels. However, granophyre (impact melt) dykes in such structures preserve clasts of supracrustal rocks, transported down from the uppermost levels of the initial structure. Studying these clasts is the only way to understand the properties of already eroded impactites. One such lithic clast from the Vredefort impact structure contains a thin pseudotachylite vein and is shown to be derived from the near-surface environment of the impact crater. Traditionally, impact pseudotachylites are referred to as in situ melt rocks with the same chemical and isotopic composition as their host rocks. The composition of the sampled pseudotachylite vein is not identical to its host rock, as shown by the micro-X-ray fluorescence (µXRF) and energy-dispersive X-ray (EDX) spectrometry mapping. Mapping shows that the melt transfer and material mixing within pseudotachylites may have commonly occurred at the upper levels of the structure. The vein is spatially related to shocked zircon and monazite crystals in the sample. Granular zircons with small granules are concentrated within and around the vein (not farther than 6–7 mm from the vein). Zircons with planar fractures and shock microtwins occur farther from the vein (6–12 mm). Zircons with microtwins (65°/{112}) are also found inside the vein, and twinned monazite (180°/[101]) is found very close to the vein. These spatial relationships point to elevated shock pressure and shear stress, concentrated along the vein’s plane during impact.

Nanostructure Fabrication: Dry Etching Damage

1991 ◽  
Vol 236 ◽  
Author(s):  
G.F. Doughty ◽  
R. Cheung ◽  
M.A. Foad ◽  
M. Rahman ◽  
N.I. Cameron ◽  
...  
Keyword(s):  
Chemical Reactivity ◽  
Compound Semiconductors ◽  
Dry Etching ◽  
Schottky Junction ◽  
Nanostructure Fabrication ◽  
X Ray ◽  
Wide Range ◽  
Directed Energy ◽  
The Impact ◽  
Surface Changes

AbstractAlthough the directed energy and chemical reactivity of dry etching permits the fabrication of nanostructures with precise geometries, it also causes unwanted electrical and optical changes to the surface, changes generally referred to as “damage”.This paper discusses the extent and the impact of dry-etching damage on rI-V and I[-VI compound semiconductors as assessed by a very wide range of techniques: the performance of devices such as MESFETs, and measurements of other properties - surface uniformly and precisely, Schottky junction characteristics, cut-off of epitaxial wire conductance, integrated photoluminescence, X-ray reflectivity, DLTS, TEM imaging and Raman scattering.We distinguish an important difference between the nature of damage on sidewalls and on surfaces normal to the directed ions, and report on progress towards establishing a model of the nature of dry etching damage. This model is applied to indicate what kinds of processes are likely to give etching with low damage.

scholarly journals Experimental investigation of size broadening of a Kα x-ray source produced by high intensity laser pulses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Gambari ◽  
R. Clady ◽  
L. Videau ◽  
O. Utéza ◽  
A. Ferré ◽  
...  
Keyword(s):  
High Intensity ◽  
Laser Intensity ◽  
Contrast Ratio ◽  
Spot Size ◽  
Source Size ◽  
Hot Electron ◽  
Temporal Contrast ◽  
X Ray ◽  
Wide Range ◽  
The Impact

AbstractThe size of a hard Kα x-ray source ($${\mathrm{E}}_{{\rm{K}}_{\rm{\alpha }}}$$ E K α = 17.48 keV) produced by a high intensity femtosecond laser interacting with a solid molybdenum target is experimentally investigated for a wide range of laser intensity (I ~ 1017–2.8 × 1019 W/cm2) and for four values of the temporal contrast ratio (6.7 × 107 < CR < 3.3 × 1010). Results point out the size enlargement of the x-ray source with the increase of laser intensity and with the deterioration of temporal contrast. It amounts up to sixteen times the laser spot size at the highest laser intensity and for the lowest temporal contrast ratio. Using hydrodynamic simulations, we evaluate the density scale length of the pre-plasma L/λ just before the main pulse peak. This allows us to show that a direct correlation with the laser absorption mechanisms is not relevant to explain the large size broadening. By varying the thickness of the molybdenum target down to 4 µm, the impact of hot electron scattering inside the solid is also proved irrelevant to explain the evolution of both the x-ray source size and the Kα photon number. We deduce that the most probable mechanism yielding to the broadening of the source size is linked to the creation of surface electromagnetic fields which confine the hot electrons at the solid surface. This assumption is supported by dedicated experiments where the evolution of the size enlargement of the x-ray source is carefully studied as a function of the laser focal spot size for the highest contrast ratio.

THE IMPACT OF LEADERSHIP PRACTICES TO TEAM MEMBERS’ SATISFACTION

2009 ◽  
Vol 8 (1) ◽  
Author(s):  
Chalimah .
Keyword(s):  
Conflict Resolution ◽  
Leadership Practices ◽  
Hotel Industry ◽  
Leader Behavior ◽  
Team Leader ◽  
Shop Floor ◽  
Team Members ◽  
Top Executives ◽  
Wide Range ◽  
The Impact

eamwork is becoming increasingly important to wide range of operations. It applies to all levels of the company. It is just as important for top executives as it is to middle management, supervisors and shop floor workers. Poor teamwork at any level or between levels can seriously damage organizational effectiveness. The focus of this paper was therefore to examine whether leadership practices consist of team leader behavior, conflict resolution style and openness in communication significantly influenced the team member’s satisfaction in hotel industry. Result indicates that team leader behavior and the conflict resolution style significantly influenced team member satisfaction. It was surprising that openness in communication did not affect significantly to the team members’ satisfaction.

Stress, anxiety, depression and burnout in frontline health care workers during COVID-19 pandemic: a brief systematic review and new data from Russia

2021 ◽  
Author(s):  
Ekaterina Mosolova ◽  
Dmitry Sosin ◽  
Sergey Mosolov
Keyword(s):  
Risk Factors ◽  
Systematic Review ◽  
Female Gender ◽  
Assessment Tools ◽  
Care Workers ◽  
Younger Age ◽  
Wide Range ◽  
Associated Risk Factors ◽  
Anxiety Depression ◽  
The Impact

During the COVID-19 pandemic, healthcare workers (HCWs) have been subject to increased workload while also exposed to many psychosocial stressors. In a systematic review we analyze the impact that the pandemic has had on HCWs mental state and associated risk factors. Most studies reported high levels of depression and anxiety among HCWs worldwide, however, due to a wide range of assessment tools, cut-off scores, and number of frontline participants in the studies, results were difficult to compare. Our study is based on two online surveys of 2195 HCWs from different regions of Russia during spring and autumn epidemic outbreaks revealed the rates of anxiety, stress, depression, emotional exhaustion and depersonalization and perceived stress as 32.3%, 31.1%, 45.5%, 74.2%, 37.7% ,67.8%, respectively. Moreover, 2.4% of HCWs reported suicidal thoughts. The most common risk factors include: female gender, nurse as an occupation, younger age, working for over 6 months, chronic diseases, smoking, high working demands, lack of personal protective equipment, low salary, lack of social support, isolation from families, the fear of relatives getting infected. These results demonstrate the need for urgent supportive programs for HCWs fighting COVID-19 that fall into higher risk factors groups.

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