scholarly journals Numerical Modelling of Radiogenic Ingrowth and Diffusion of Pb in Apatite Inclusions with Variable Shape and U-Th Zonation

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 364
Author(s):  
Daniil V. Popov ◽  
Richard A. Spikings
Keyword(s):  
Numerical Modelling ◽  
Volume Diffusion ◽  
Radiogenic Isotopes ◽  
Open Boundary ◽  
Future Research ◽  
Variable Shape ◽  
Simple Geometry ◽  
Thermal Histories ◽  
And Diffusion ◽  
Infinite Reservoir

The fundamental premise of apatite U-Th-Pb thermochronology is that radiogenic Pb is redistributed by volume diffusion. In practice, it is often additionally assumed that crystals (1) lose radiogenic Pb to an infinite reservoir, (2) have a simple geometry and (3) are chemically homogeneous. Here we explore the significance of the latter three assumptions by numerical modelling of Pb radiogenic ingrowth and diffusion in apatite inclusions within other minerals. Our results indicate that the host minerals are likely to hamper diffusive Pb loss from the apatite inclusions by limiting the Pb flux across their boundaries, and thus the thermal histories that are reconstructed assuming a fully open boundary may be significantly inaccurate, precluding a meaningful interpretation. We also find that when apatite boundaries are flux-limited, heterogeneities in U and Th concertation within apatite have subordinate effect on bulk-grain U-Th-Pb dates and can cause intra-grain U-Th-Pb dates to increase towards the boundaries. Finally, we show that it is important to correctly account for crystal geometry when modelling intra-grain U-Th-Pb dates. We suggest that the effect of surrounding minerals on diffusive Pb loss from apatite (and loss of other radiogenic isotopes from other minerals) should be examined more closely in future research.

Imaging of feeding and eating disorders

2020 ◽  
pp. 1075-1086
Author(s):  
Natalie Kurniadi ◽  
Christina E. Wierenga ◽  
Laura A. Berner ◽  
Walter H. Kaye
Keyword(s):  
Eating Disorders ◽  
Diffusion Tensor ◽  
Future Research ◽  
Neural Pathways ◽  
Eating Behaviours ◽  
Feeding And Eating Disorders ◽  
Positron Emission ◽  
Life Threatening ◽  
Magnetic Resonance Imaging Mri ◽  
And Diffusion

The conceptual framework regarding the aetiology of eating disorders (EDs) has changed dramatically in recent decades. Cutting-edge neuroimaging techniques have led to advancements in understanding the underlying neurobiology of anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). Techniques such as magnetic resonance imaging (MRI), positron emission tomography (PET), and diffusion tensor imaging (DTI) allow the opportunity to examine not only structural, but also functional, abnormalities that contribute to extreme eating behaviours characteristic of these life-threatening disorders. Furthermore, research using imaging paradigms suggests that variations in neurobiology are associated with traits that persist after recovery. This chapter will provide insights regarding neural pathways involved in the processing of appetite, reward, mood, body perception, and cognitive inhibition as they pertain to EDs. Findings relevant to feeding disorders will also be discussed. Conclusions will include considerations of treatment applications and directions for future research.

scholarly journals A Framework for Evaluating Variation in (U-Th)/He Datasets

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1111
Author(s):  
Francis J. Sousa ◽  
Kenneth A. Farley
Keyword(s):  
Thermal History ◽  
Synthetic Data ◽  
Diffusion Parameters ◽  
Modeling Software ◽  
History Of ◽  
Single Grain ◽  
Thermal Histories ◽  
The Impact ◽  
And Diffusion ◽  
New Framework

This paper presents a framework for evaluating variation in (U-Th)/He datasets. The framework is objective, repeatable, and based on compatibility of thermal histories derived from individual (U-Th)/He dates. The structure of this new method includes three fundamental steps. First, the allowable thermal history of each individual grain is quantitatively constrained with a model. Second, the thermal histories of all grains from a sample are visualized on the same axes. Third, the compatibility of the allowable thermal histories of each individual grain is evaluated. This allows a user to assess whether variation among single grain dates can plausibly be explained (referred to here as legitimate) or not (illegitimate). Additionally, this methodology allows for accurate representation of the impact that illegitimate variation has on the thermal history constraints of a sample. We demonstrate the application of this new framework using a variety of examples from the literature, as well as with synthetic data. Modeling presented here is executed using the modeling software QTQt (version 5.6.0) and the He diffusion kinetics based on the radiation damage accumulation and annealing model, but the framework is designed to be easily adaptable to any modeling software and diffusion parameters.

scholarly journals Human sweat monitoring using polymer-based fiber

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Taekyung Lim ◽  
Youngseok Kim ◽  
Sang-Mi Jeong ◽  
Chi-Hyeong Kim ◽  
Seong-Min Kim ◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Human Body ◽  
Pure Water ◽  
Body Movement ◽  
Wearable Sensors ◽  
Chloride Concentration ◽  
Chloride Ions ◽  
Coagulation Bath ◽  
Future Research ◽  
Simple Geometry

AbstractLightweight nano/microscale wearable devices that are directly attached to or worn on the human body require enhanced flexibility so that they can facilitate body movement and overall improved wearability. In the present study, a flexible poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) fiber-based sensor is proposed, which can accurately measure the amount of salt (i.e., sodium chloride) ions in sweat released from the human body or in specific solutions. This can be performed using one single strand of hair-like conducting polymer fiber. The fabrication process involves the introduction of an aqueous PEDOT:PSS solution into a sulfuric acid coagulation bath. This is a repeatable and inexpensive process for producing monolithic fibers, with a simple geometry and tunable electrical characteristics, easily woven into clothing fabrics or wristbands. The conductivity of the PEDOT:PSS fiber increases in pure water, whereas it decreases in sweat. In particular, the conductivity of a PEDOT:PSS fiber changes linearly according to the concentration of sodium chloride in liquid. The results of our study suggest the possibility of PEDOT:PSS fiber-based wearable sensors serving as the foundation of future research and development in skin-attachable next-generation healthcare devices, which can reproducibly determine the physiological condition of a human subject by measuring the sodium chloride concentration in sweat.

scholarly journals Physical and Numerical Modelling of Post-Pumping Seawater Intrusion

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Leonard Stoeckl ◽  
Marc Walther ◽  
Leanne K. Morgan
Keyword(s):  
Flow Field ◽  
Numerical Modelling ◽  
Seawater Intrusion ◽  
Future Research ◽  
Hydrogeological Parameters ◽  
Well Location ◽  
Physical Experiments ◽  
Parameters Extraction ◽  
Coastal Boundary ◽  
First Time

This paper explores post-pumping seawater intrusion (PP-SWI), which is the phenomenon of seawater intruding further inland than the location of a well, after pumping has ceased. Despite numerous papers on the topic of seawater intrusion and pumping, this is the first time that PP-SWI has been described in the literature, to our knowledge. This paper describes a laboratory-scale investigation of the phenomenon and we demonstrate that PP-SWI can be reproduced within physical experiments. We also show, using numerical modelling, that PP-SWI is caused by disequilibrium in the flow field following the cessation of pumping. Specifically, in our simulations, the cone of depression persisted after the cessation of pumping (first moving inland and then retreating toward the coastal boundary) which caused a lag in the reestablishment of fresh water flow toward the coast, after pumping had stopped. It was during this period of flow-field disequilibrium that PP-SWI occurred. We expect systems with larger postextraction disequilibrium to be most susceptible to PP-SWI and recommend future research to improve understanding of the relationship between hydrogeological parameters, extraction rates, well location, and incidence of PP-SWI. In those systems where PP-SWI is most likely, quantitative analysis of groundwater extraction and SWI will need to employ transient approaches to ensure that SWI is not underestimated.

Implications and Future Trends

2008 ◽  
pp. 296-303
Author(s):  
Yogesk K. Dwivedi
Keyword(s):  
Service Providers ◽  
Research Trends ◽  
Future Research ◽  
Future Trends ◽  
Internet Service ◽  
Policy Makers ◽  
Broadband Service ◽  
Adoption And Diffusion ◽  
The Government ◽  
And Diffusion

This chapter presents the implications of the research discussed in this book and outlines future research trends in the area of consumer adoption and usage of broadband. The findings of the studies detailed in this book generate a number of implications that may be relevant to policy makers, Internet service providers (ISPs), and other relevant stakeholders for increasing consumers’ adoption of broadband. The chapter begins by a discussion concerning the implications of this research for the government, followed by the implications for the Internet/broadband service providers and, ultimately, the implications for content providers and emerging electronic services. Finally, a discussion on the future trends in the area of broadband adoption and diffusion is provided.

Consumer Acceptance of the Mobile Internet

2015 ◽  
pp. 151-161
Author(s):  
Joerg Koenigstorfer
Keyword(s):  
Technology Acceptance ◽  
Diffusion Of Innovation ◽  
Empirical Studies ◽  
Mobile Internet ◽  
Consumer Acceptance ◽  
Future Research ◽  
Use Of Technology ◽  
Acceptance Model ◽  
Acceptance Research ◽  
And Diffusion

Today, the majority of the world's population owns mobile devices that allow individuals to access the Internet at any time and at any place. However, owning an Internet-enabling mobile device does not necessarily mean that an individual uses the mobile Internet. This article reviews the state of the art on the theory-guided drivers and barriers of consumer acceptance of the mobile Internet. The author describes models that help explain and predict consumer acceptance, including the Technology Acceptance Model, Motivational models, Perceived Value models, The Unified Theory of Acceptance and Use of Technology, and Diffusion of Innovation theories. The article also presents empirical research that applies and extends these models in the context of mobile Internet usage, and summarizes the most important findings of these empirical studies. Finally, this article also discusses challenges in acceptance research, as well as implications for future research.

Health Misinformation

2021 ◽  
Author(s):  
Xiaoli Nan ◽  
Yuan Wang ◽  
Kathryn Thier
Keyword(s):  
Scientific Information ◽  
Conclusive Evidence ◽  
Future Research ◽  
Health Issues ◽  
The Many ◽  
Many Sources ◽  
Feature Negative ◽  
The Impact ◽  
And Diffusion ◽  
Harmful Effects

Research on health misinformation has grown rapidly as concerns about the potential harmful effects of health misinformation on individuals and society intensify amid a “post-truth” era. In this chapter, we provide a broad overview of current research and evidence concerning the many facets of health misinformation, including its sources, prevalence, characteristics (both content and diffusion features), impact, and mitigation. We conclude that health misinformation originates from many sources, most notably mass and social media; is fairly prevalent, both in interpersonal and mediated settings; and tends to feature negative sentiments, anecdotal evidence, and anti-science narratives. Although there is no conclusive evidence that health misinformation spreads more broadly than scientific information, health misinformation reliably leads to misperceptions on health issues. Efforts to mitigate the impact of health misinformation show early promise in correcting misperceptions. We offer several directions for future research.

What are we dating, volume diffusion or recrystallisation? Isotopic modelling and trace-element analysis as tools to interpret the high-temperature U-Pb thermochronometer in apatite and rutile

2020 ◽  
Author(s):  
Chris Mark ◽  
J. Stephen Daly ◽  
David Chew ◽  
Nathan Cogné
Keyword(s):  
High Temperature ◽  
Trace Element ◽  
Thermal History ◽  
Volume Diffusion ◽  
Trace Element Analysis ◽  
Granulite Facies ◽  
Forward Modelling ◽  
Earth Planet ◽  
Element Analysis ◽  
Thermal Histories

<p>The availability of high-temperature thermochronometers suitable for generation of continuous thermal histories at mid- to lower-crustal temperatures (i.e., ≥ 400 °C) is limited. Available thermochronometers include the recently developed apatite and rutile U-Pb thermochronometers ( ≤ 550 and 640 °C; Kooijman et al., 2010; Cochrane et al., 2014) and arguably the K-Ar system in white mica (sensitive to temperatures ≤ 500 °C. Recent work has focussed on micro-beam U-Pb analysis of apatite and rutile by sector-field and multi-collector LA-ICPMS to generate single-crystal U-Pb age profiles. Such profiles can be inverted to yield continuous thermal histories for high-temperature processes (e.g., Smye et al., 2018). However, both apatite and rutile can exhibit crystal growth and dissolution-reprecipitation reactions in the same temperature ranges at which measurable Pb diffusion occurs: neither behaves as a pure thermochronometer in all circumstances (e.g., Chambers and Kohn, 2012; Harlov et al., 2005). Thus, it is critical to develop protocols which unequivocally identify age profiles arising from volume diffusion.</p><p>Here, we present case studies from greenschist- to granulite-facies-grade metamorphic systems from the Eastern Alps and the Western Gneiss Region of Norway. We demonstrate the utility of trace-element analysis (Sr-Y-REE-Th-U) and isotopic forward modelling to discriminate age resetting arising from (re)crystallisation from diffusion. Both rutile and especially apatite routinely incorporate non-trivial amounts of common-Pb during crystallisation (as opposed to radiogenic Pb generated by <em>in-situ</em> radionuclide decay), rendering them discordant in U-Pb isotope space. This common-Pb must be corrected for during age calculation. However, common-Pb is isotopically distinct from radiogenic Pb but exhibits the same diffusion behaviour, so the predicted U-Pb isotopic distribution for a given crystal arising from a proposed thermal history can be estimated by isotopic forward modelling. Thus, common-Pb can be exploited to validate both the assumption of Pb-loss by volume diffusion, and the thermal history predicted by age profile inversion.</p><p><strong>Chambers</strong>, J.A., & Kohn, M.J., Am. Mineral., 97, 543–555 (2012); <strong>Cochrane</strong>, R., et al., Geochim. Cosmochim. Acta, 127, 39–56, (2014); <strong>Harlov</strong>, D.E., et al., Contrib. Mineral. Petrol, 150, 268–286 (2005); <strong>Kooijman</strong>, E., et al., Earth Planet. Sci. Lett, 293, 321–330, (2010); <strong>Smye</strong>, A.J., et al., Chem. Geol., 494, 1–18 (2018).</p>

Introduction

2012 ◽  
Author(s):  
Frank Trentmann
Keyword(s):  
Material Culture ◽  
Social Order ◽  
Well Being ◽  
Modern World ◽  
Future Research ◽  
Consumer Society ◽  
The Public ◽  
Global Exchange ◽  
The Relationship ◽  
And Diffusion

This volume follows several of the most exciting recent pathways into consumption and its history, re-examines old debates, and looks ahead to questions for future research. It looks at several rich traditions of material culture that existed prior to modernity with which consumer society is often conflated. The book examines the public as well as private face of consumption, in relation to public life and social order as well as the organization of households and social groups. It also discusses the movement of goods between societies, along with questions of global exchange and diffusion in the early modern world. The book then explores luxury and necessity, the luxury wars, patterns of possessions and diet in town and country, changes in the standard of living, the life cycle of consumption from the desire to consume in the future (saving), the use of energy to be comfortable and run things, and the politics of consumption. Finally, it considers the relationship between consumers and civil society, status, family life, generational identities, fashion, and well-being.

Future Research on Cloud Computing Adoption by Small and Medium-Sized Enterprises

2013 ◽  
Vol 5 (2) ◽  
pp. 1-16 ◽  
Author(s):  
Amin Saedi ◽  
Noorminshah A. Iahad
Keyword(s):  
Cloud Computing ◽  
Technology Acceptance ◽  
Diffusion Of Innovation ◽  
Actor Network Theory ◽  
Future Research ◽  
Diffusion Of Innovation Theory ◽  
Adoption Theory ◽  
Cloud Computing Adoption ◽  
Acceptance Model ◽  
And Diffusion

This paper delivers some initial insights into the range of theories that need to be integrated to provide a holistic explanation of Cloud Computing (CC) adoption by Small and Medium-Sized Enterprises (SMEs). To achieve this outcome, this paper firstly critiques the two commonly used Information Systems (IS) adoption/diffusion theories: the Technology Acceptance Model and Diffusion of Innovation Theory. It then evaluates the suitability of the Technology-Organization-Environment framework as an IS adoption theory and Actor-network Theory as an innovation translation approach for future research on developing an integrated theoretical framework for CC adoption by SMEs.

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