The impact of growth rate on trace-element and Li-isotope composition of inorganically precipitated calcium carbonates

2006 ◽  
Vol 70 (18) ◽  
pp. A398
Author(s):  
A.J. Mason ◽  
G.M. Henderson
Keyword(s):  
Growth Rate ◽  
Trace Element ◽  
Isotope Composition ◽  
Calcium Carbonates ◽  
Li Isotope ◽  
The Impact

scholarly journals Technical note: Lithium isotopes in dolostone as a palaeo-environmental proxy – an experimental approach

2019 ◽  
Vol 15 (2) ◽  
pp. 635-646 ◽  
Author(s):  
Holly L. Taylor ◽  
Isaac J. Kell Duivestein ◽  
Juraj Farkas ◽  
Martin Dietzel ◽  
Anthony Dosseto
Keyword(s):  
Isotope Fractionation ◽  
Isotope Composition ◽  
Relative Proportion ◽  
Significant Proportion ◽  
Technical Note ◽  
Fractionation Factor ◽  
Calcium Carbonates ◽  
Marine Carbonates ◽  
Li Isotope ◽  
Environmental Proxy

Abstract. Lithium (Li) isotopes in marine carbonates have considerable potential as a proxy to constrain past changes in silicate weathering fluxes and improve our understanding of Earth's climate. To date the majority of Li isotope studies on marine carbonates have focussed on calcium carbonates. The determination of the Li isotope fractionation between dolomite and a dolomitizing fluid would allow us to extend investigations to deep times (i.e. Precambrian) when dolostones were the most abundant marine carbonate archives. Dolostones often contain a significant proportion of detrital silicate material, which dominates the Li budget; thus, pretreatment needs to be designed so that only the isotope composition of the carbonate-associated Li is measured. This study aims to serve two main goals: (1) to determine the Li isotope fractionation between Ca–Mg carbonates and solution, and (2) to develop a method for leaching the carbonate-associated Li out of dolostone while not affecting the Li contained within the detrital portion of the rock. We synthesized Ca–Mg carbonates at high temperatures (150 to 220 ∘C) and measured the Li isotope composition (δ7Li) of the precipitated solids and their respective reactive solutions. The relationship of the Li isotope fractionation factor with temperature was obtained: 103ln⁡αprec-sol=-(2.56±0.27)106(1)/T2+(5.8±1.3) Competitive nucleation and growth between dolomite and magnesite were observed during the experiments; however, there was no notable effect of their relative proportion on the apparent Li isotope fractionation. We found that Li isotope fractionation between the precipitated solid and solution is higher for Ca–Mg carbonates than for Ca carbonates. If the temperature of a precipitating solution is known or can be estimated independently, the above equation could be used in conjunction with the Li isotope composition of dolostones to derive the composition of the solution and hence make inferences about the past Li cycle. In addition, we also conducted leaching experiments on a Neoproterozoic dolostone and a Holocene coral. Results show that leaching with 0.05 M hydrochloric acid (HCl) or 0.5 % acetic acid (HAc) at room temperature for 60 min releases Li from the carbonate fraction without a significant contribution of Li from the siliciclastic detrital component. These experimental and analytical developments provide a basis for the use of Li isotopes in dolostones as a palaeo-environmental proxy, which will contribute to further advance our understanding of the evolution of Earth's surface environments.

International trade: Research of the reasons for the fall

2019 ◽  
pp. 79-91 ◽  
Author(s):  
V. S. Nazarov ◽  
S. S. Lazaryan ◽  
I. V. Nikonov ◽  
A. I. Votinov
Keyword(s):  
Growth Rate ◽  
International Trade ◽  
Exchange Rate ◽  
Global Economy ◽  
Structural Changes ◽  
Global Value Chains ◽  
Value Chains ◽  
Negative Contribution ◽  
Basic Commodity ◽  
The Impact

The article assesses the impact of various factors on the growth rate of international trade. Many experts interpreted the cross-border flows of goods decline against the backdrop of a growing global economy as an alarming sign that indicates a slowdown in the processes of globalization. To determine the reasons for the dynamics of international trade, the decompositions of its growth rate were carried out and allowed to single out the effect of the dollar exchange rate, the commodities prices and global value chains on the change in the volume of trade. As a result, it was discovered that the most part of the dynamics of international trade is due to fluctuations in the exchange rate of the dollar and prices for basic commodity groups. The negative contribution of trade within global value chains in 2014 was also revealed. During the investigated period (2000—2014), such a picture was observed only in the crisis periods, which may indicate the beginning of structural changes in the world trade.

scholarly journals The impact of non-pharmaceutical interventions on COVID-19 epidemic growth in the 37 OECD member states

2021 ◽  
Author(s):  
Francisco Pozo-Martin ◽  
Heide Weishaar ◽  
Florin Cristea ◽  
Johanna Hanefeld ◽  
Thurid Bahr ◽  
...  
Keyword(s):  
Growth Rate ◽  
Early Phase ◽  
Policy Decision ◽  
Multilevel Modelling ◽  
Daily Growth ◽  
Public Places ◽  
Member States ◽  
Unit Increase ◽  
Policy Decision Making ◽  
The Impact

AbstractWe estimated the impact of a comprehensive set of non-pharmeceutical interventions on the COVID-19 epidemic growth rate across the 37 member states of the Organisation for Economic Co-operation and Development during the early phase of the COVID-19 pandemic and between October and December 2020. For this task, we conducted a data-driven, longitudinal analysis using a multilevel modelling approach with both maximum likelihood and Bayesian estimation. We found that during the early phase of the epidemic: implementing restrictions on gatherings of more than 100 people, between 11 and 100 people, and 10 people or less was associated with a respective average reduction of 2.58%, 2.78% and 2.81% in the daily growth rate in weekly confirmed cases; requiring closing for some sectors or for all but essential workplaces with an average reduction of 1.51% and 1.78%; requiring closing of some school levels or all school levels with an average reduction of 1.12% or 1.65%; recommending mask wearing with an average reduction of 0.45%, requiring mask wearing country-wide in specific public spaces or in specific geographical areas within the country with an average reduction of 0.44%, requiring mask-wearing country-wide in all public places or all public places where social distancing is not possible with an average reduction of 0.96%; and number of tests per thousand population with an average reduction of 0.02% per unit increase. Between October and December 2020 work closing requirements and testing policy were significant predictors of the epidemic growth rate. These findings provide evidence to support policy decision-making regarding which NPIs to implement to control the spread of the COVID-19 pandemic.

scholarly journals The Impact of Policy Measures on Human Mobility, COVID-19 Cases, and Mortality in the US: A Spatiotemporal Perspective

2021 ◽  
Vol 18 (3) ◽  
pp. 996
Author(s):  
Yun Li ◽  
Moming Li ◽  
Megan Rice ◽  
Haoyuan Zhang ◽  
Dexuan Sha ◽  
...  
Keyword(s):  
Growth Rate ◽  
Human Mobility ◽  
Public Information ◽  
Key Factors ◽  
Information Campaigns ◽  
Rapid Spread ◽  
The Us ◽  
Policy Measures ◽  
The Impact ◽  
At Home

Social distancing policies have been regarded as effective in containing the rapid spread of COVID-19. However, there is a limited understanding of policy effectiveness from a spatiotemporal perspective. This study integrates geographical, demographical, and other key factors into a regression-based event study framework, to assess the effectiveness of seven major policies on human mobility and COVID-19 case growth rates, with a spatiotemporal emphasis. Our results demonstrate that stay-at-home orders, workplace closures, and public information campaigns were effective in decreasing the confirmed case growth rate. For stay-at-home orders and workplace closures, these changes were associated with significant decreases (p < 0.05) in mobility. Public information campaigns did not see these same mobility trends, but the growth rate still decreased significantly in all analysis periods (p < 0.01). Stay-at-home orders and international/national travel controls had limited mitigation effects on the death case growth rate (p < 0.1). The relationships between policies, mobility, and epidemiological metrics allowed us to evaluate the effectiveness of each policy and gave us insight into the spatiotemporal patterns and mechanisms by which these measures work. Our analysis will provide policymakers with better knowledge regarding the effectiveness of measures in space–time disaggregation.

Ratcheting assessment of corroded elbow pipes subjected to internal pressure and cyclic bending moment

2021 ◽  
pp. 030932472198989
Author(s):  
Ali Salehi ◽  
Armin Rahmatfam ◽  
Mohammad Zehsaz
Keyword(s):  
Growth Rate ◽  
Stainless Steel ◽  
Internal Pressure ◽  
Bending Moment ◽  
Axial Direction ◽  
Hoop Strain ◽  
Cyclic Bending ◽  
High Fatigue ◽  
The Impact ◽  
Cyclic Bending Moment

The present study aimed to study ratcheting strains of corroded stainless steel 304LN elbow pipes subjected to internal pressure and cyclic bending moment. To this aim, spherical and cubical shapes corrosion are applied at two depths of 1 mm and 2 mm in the critical points of elbow pipe such as symmetry sites at intrados, extrados, and crown positions. Then, a Duplex 2205 stainless steel elbow pipe is considered as an alternative to studying the impact of the pipe materials, due to its high corrosion resistance and strength, toughness, and most importantly, the high fatigue strength and other mechanical properties than stainless steel 304LN. In order to perform numerical analyzes, the hardening coefficients of the materials were calculated. The results highlight a significant relationship between the destructive effects of corrosion and the depth and shape of corrosion, so that as corrosion increases, the resulting destructive effects increases as well, also, the ratcheting strains in cubic corrosions have a higher growth rate than spherical corrosions. In addition, the growth rate of the ratcheting strains in the hoop direction is much higher across the studied sample than the axial direction. The highest growth rate of hoop strain was observed at crown and the highest growth rate of axial strains occurred at intrados position. Altogether, Duplex 2205 material has a better performance than SS 304LN.

The impact of temperature on the degree of structurization of water of different isotope composition

2017 ◽  
Vol 39 (4) ◽  
pp. 185-190
Author(s):  
V. V. Goncharuk ◽  
I. Yu. Romanyukina ◽  
M. D. Skil’skaya ◽  
A. I. Marynin ◽  
A. V. Syroeshkin ◽  
...  
Keyword(s):  
Isotope Composition ◽  
The Impact

scholarly journals Diet-Induced Obesity Disrupts Trace Element Homeostasis and Gene Expression in the Olfactory Bulb

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3909
Author(s):  
Melissa S. Totten ◽  
Derek M. Pierce ◽  
Keith M. Erikson
Keyword(s):  
Gene Expression ◽  
Olfactory Bulb ◽  
Trace Element ◽  
Alpha Synuclein ◽  
Divalent Metal Transporter 1 ◽  
Diet Induced Obesity ◽  
Mrna Gene ◽  
The Impact ◽  
Mrna Gene Expression ◽  
Obese Male

The aim of this study was to determine the impact of diet-induced obesity (DIO) on trace element homeostasis and gene expression in the olfactory bulb and to identify potential interaction effects between diet, sex, and strain. Our study is based on evidence that obesity and olfactory bulb impairments are linked to neurodegenerative processes. Briefly, C57BL/6J (B6J) and DBA/2J (D2J) male and female mice were fed either a low-fat diet or a high-fat diet for 16 weeks. Brain tissue was then evaluated for iron, manganese, copper, and zinc concentrations and mRNA gene expression. There was a statistically significant diet-by-sex interaction for iron and a three-way interaction between diet, sex, and strain for zinc in the olfactory bulb. Obese male B6J mice had a striking 75% increase in iron and a 50% increase in manganese compared with the control. There was an increase in zinc due to DIO in B6J males and D2J females, but a decrease in zinc in B6J females and D2J males. Obese male D2J mice had significantly upregulated mRNA gene expression for divalent metal transporter 1, alpha-synuclein, amyloid precursor protein, dopamine receptor D2, and tyrosine hydroxylase. B6J females with DIO had significantly upregulated brain-derived neurotrophic factor expression. Our results demonstrate that DIO has the potential to disrupt trace element homeostasis and mRNA gene expression in the olfactory bulb, with effects that depend on sex and genetics. We found that DIO led to alterations in iron and manganese predominantly in male B6J mice, and gene expression dysregulation mainly in male D2J mice. These results have important implications for health outcomes related to obesity with possible connections to neurodegenerative disease.

The effect of intangible assets on sustainable growth and firm value – Evidence on intellectual capital investment in companies listed on Bucharest Stock Exchange

Kybernetes ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Catalin Ionita ◽  
Elena Dinu
Keyword(s):  
Growth Rate ◽  
Intellectual Capital ◽  
Firm Value ◽  
Intangible Assets ◽  
Stock Exchange ◽  
Listed Companies ◽  
Sustainable Growth ◽  
Content Type ◽  
Sustainable Growth Rate ◽  
The Impact

PurposeThe present study investigates the connection between company investments in intellectual capital (IC) and how they translate into financial value. The aim is to test the impact of intangible assets on the firm value and its sustainable growth.Design/methodology/approachThe research employs computation models to determine the sustainable growth rate (SGR) and the firm value (FV), and by using the ordinary least squares (OLS) model through a linear regression assesses the relationship between the dependent variables and expenditures on intangibles like R&D, IT programs and patents. A sample of 42 companies has been selected out of the 78 listed at Bucharest Stock Exchange (BSE), based on the appropriateness of the information disclosed in the financial reports for the period 2016–2019.FindingsThe results show that intangibles classified as innovative competences (R&D and Patents) do not have a positive impact on SGR and FV in listed companies from Romania. Moreover, R&D has a negative and significant effect on FV, while IT Programs have a positive and significant impact on FV, but not on the SGR. Variables categorised as economic competencies (Brands, Shares held in associates and jointly controlled entities) and firm structure-specific variables (Leverage, Firm Performance) seem to have a significant effect on SGR and FV. Shares held in associates and jointly controlled entities is the variable that can have the biggest impact when it comes to FV for companies listed at BSE.Research limitations/implicationsDue to non-disclosure of specific information by some companies, or lack of investments in intangibles the sample had to be reduced and does not cover all listed companies.Practical implicationsCompanies listed on the Regulated Market from the Bucharest Stock Exchange should maintain their scale of liabilities at a reasonable level when financing intangible assets in order to ensure corporate long-term and sustainable development. Also, these companies should maintain awareness about the importance of intangible assets and invest more in specific sub-components, in order to sustain competitive advantage. Recognizing the roles of intangibles, managers need to develop strategies to invest in profitable intangibles by reasonably allocating their limited resources, in order to achieve sustainable growth and increase company success.Originality/valueStudies concerning the relation between investments in intangibles and sustainable growth rate and firm value of listed Romanian companies are very scarce. This paper reveals new research, never before undertaken, concerning expenditures on intangibles by Romanian companies and the valuation of such investments on Bucharest Stock Exchange.

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