scholarly journals Atmospheric Radiocarbon: Implications for the Geomagnetic Dipole Moment

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 239-248 ◽  
Author(s):  
R S Sternberg ◽  
P E Damon
Keyword(s):  
Dipole Moment ◽  
Secular Variation ◽  
Fluid Motion ◽  
Outer Core ◽  
The Past ◽  
Geochemical Cycle ◽  
Difference Form ◽  
Physical Fields ◽  
Geomagnetic Dipole ◽  
Insight Into

The geomagnetic field is one of the major physical fields of the earth. Because its source is fluid motion in the outer core, it exhibits temporal changes, called secular variation, which are quite rapid compared to most geologic phenomena. The prehistoric secular variation is usually inferred from paleomagnetic data. We will discuss here how changes in the atmospheric 14C content can be used to gain additional insight into the behavior of the dipole moment over the past 8500 years. By rewriting the differential equations representing the 14C geochemical cycle in finite-difference form, we are able to convert the atmospheric 14C activity record into an equivalent radiocarbon dipole moment.

Tree-rings, absolute chronology and climatic change

1995 ◽  
Vol 3 (4) ◽  
pp. 303-308 ◽  
Author(s):  
Bernd Kromer ◽  
Bernd Becker
Keyword(s):  
Dipole Moment ◽  
Tree Ring ◽  
Tree Rings ◽  
Time Scale ◽  
Vegetation History ◽  
Cosmogenic Nuclides ◽  
The Past ◽  
Geochemical Constraints ◽  
Geomagnetic Dipole ◽  
Insight Into

In the Hohenheim tree-ring laboratory, two long tree-ring chronologies have been built, spanning the past 11 600 years. This is the world's longest continuous tree-ring calendar. It has become the backbone of the calibration of the radiocarbon time scale, offering absolute and accurate dates for archaeology, vegetation history and paleoclimate studies. 14C analyses of the tree-ring chronologies provide insight into the process controlling the production of cosmogenic nuclides, i.e. mainly the geomagnetic dipole moment and solar variability. They also set geochemical constraints to variations in the carbon cycle during a major climatic excursion.

scholarly journals Implications of Dipole Moment Secular Variation from 50,000–10,000 Years for the Radiocarbon Record

Radiocarbon ◽  
1992 ◽  
Vol 34 (2) ◽  
pp. 189-198 ◽  
Author(s):  
R. S. Sternberg ◽  
P. E. Damon
Keyword(s):  
Dipole Moment ◽  
Production Function ◽  
Secular Variation ◽  
Good Match ◽  
Average Value ◽  
The Past ◽  
Dc Gain ◽  
Ramp Function ◽  
Holocene Record ◽  
Linear Ramp

Sparse paleointensity data from 10–50 ka suggest that the average dipole moment (DM) was 50–75% of the average of 8.67 μ 1022 A m2 for the past 5 Ma, and 8.75 μ 1022 for the past 12 ka. A linear ramp function, increasing the DM from 4 to 8.75 μ 1022 A m2 between 50–10 ka BP, generates a total 14C inventory of 126 dpm/cme2, agreeing very well with an inventory assay of 128 dpm/cme2, which includes 14C in sediments. With the Lingenfelter and Ramaty (1970) production function and a model DC gain of about 100, this DM function would give a Δ14C of 500‰ at 20 ka BP, consistent with the Barbados coral record, and also gives a good match to the Holocene record. A Laschamp geomagnetic event at about 45 ka BP, with a DM of 25% of its average value and lasting 5 ka, would only increase the present inventory by 0.3–1.2 dpm/cme2, and would probably have only a small effect on Δ14C at 20 ka BP, but could produce a short-lived 14C spike of over 500‰.

scholarly journals Secular variation of the geomagnetic dipole during the past 2000 years

2008 ◽  
Vol 9 (1) ◽  
pp. n/a-n/a ◽  
Author(s):  
Jean-Pierre Valet ◽  
Emilio Herrero-Bervera ◽  
Jean-Louis LeMouël ◽  
Guillaume Plenier
Keyword(s):  
Secular Variation ◽  
The Past ◽  
Past 2000 Years ◽  
Geomagnetic Dipole

scholarly journals ORBITAL NOISE OF THE EARTH CAUSES INTENSITY FLUCTUATION IN THE GEOMAGNETIC FIELD

2003 ◽  
Vol 03 (01) ◽  
pp. L63-L72 ◽  
Author(s):  
H. S. LIU ◽  
R. KOLENKIEWLCZ ◽  
C. WADE
Keyword(s):  
Geomagnetic Field ◽  
Noise Spectrum ◽  
Outer Core ◽  
The Past ◽  
The Earth ◽  
Spectral Peaks ◽  
Relative Paleointensity ◽  
Intensity Fluctuations ◽  
Composite Curve ◽  
Insight Into

Orbital noise of Earth's obliquity can provide an insight into the core of the Earth that causes intensity fluctuations in the geomagnetie field. Here we show that noise spectrum of the obliquity frequency have revealed a series of frequency periods centered at 250-, 100-, 50-, 41-, 30-, and 26-kyr which are almost identical with the observed spectral peaks from the composite curve of 33 records of relative paleointensity spanning the past 800 kyr (Sint–800 data). A continuous record for the past two million years also reveals the presence of the major 100 kyr periodicity in obliquity noise and geomagnetic intensity fluctuations. These results of correlation suggest that obliquity noise may power the dynamo, located in the liquid outer core of the Earth, which generates the geomagnetic field.

Variations in the geomagnetic dipole moment during the Holocene and the past 50 kyr

2008 ◽  
Vol 272 (1-2) ◽  
pp. 319-329 ◽  
Author(s):  
Mads Faurschou Knudsen ◽  
Peter Riisager ◽  
Fabio Donadini ◽  
Ian Snowball ◽  
Raimund Muscheler ◽  
...  
Keyword(s):  
Dipole Moment ◽  
The Holocene ◽  
The Past ◽  
Geomagnetic Dipole

Recovery boiler sootblowers: History and technological advances

TAPPI Journal ◽  
2015 ◽  
Vol 14 (1) ◽  
pp. 51-60
Author(s):  
HONGHI TRAN ◽  
DANNY TANDRA
Keyword(s):  
Cfd Modeling ◽  
Computing Systems ◽  
The Past ◽  
Technological Advances ◽  
Recovery Boilers ◽  
Computational Fluid Dynamics Cfd ◽  
Recovery Boiler ◽  
Steam Parameters ◽  
Insight Into ◽  
Deposit Removal

Sootblowing technology used in recovery boilers originated from that used in coal-fired boilers. It started with manual cleaning with hand lancing and hand blowing, and evolved slowly into online sootblowing using retractable sootblowers. Since 1991, intensive research and development has focused on sootblowing jet fundamentals and deposit removal in recovery boilers. The results have provided much insight into sootblower jet hydrodynamics, how a sootblower jet interacts with tubes and deposits, and factors influencing its deposit removal efficiency, and have led to two important innovations: fully-expanded sootblower nozzles that are used in virtually all recovery boilers today, and the low pressure sootblowing technology that has been implemented in several new recovery boilers. The availability of powerful computing systems, superfast microprocessors and data acquisition systems, and versatile computational fluid dynamics (CFD) modeling capability in the past two decades has also contributed greatly to the advancement of sootblowing technology. High quality infrared inspection cameras have enabled mills to inspect the deposit buildup conditions in the boiler during operation, and helped identify problems with sootblower lance swinging and superheater platens and boiler bank tube vibrations. As the recovery boiler firing capacity and steam parameters have increased markedly in recent years, sootblowers have become larger and longer, and this can present a challenge in terms of both sootblower design and operation.

Upcoming Drifts In Bio-Similars

2020 ◽  
Vol 15 ◽  
Author(s):  
Geeta Aggarwal ◽  
Manju Nagpal ◽  
Ameya Sharma ◽  
Vivek Puri ◽  
Gitika Arora Dhingra
Keyword(s):  
Metabolic Diseases ◽  
Market Competition ◽  
Current Status ◽  
Medicinal Products ◽  
The Past ◽  
Biologic Activity ◽  
Emerging Trends ◽  
Regulatory Guidelines ◽  
Food Drug Administration ◽  
Insight Into

Background: Biopharmaceuticals such as Biologic medicinal products have been in clinical use over the past three decades and have benefited towards the therapy of degenerative and critical metabolic diseases. It is forecasted that market of biologics will be going to increase at a rate of 20% per year, and by 2025, more than ˃ 50% of new drug approvals may be biological products. The increasing utilization of the biologics necessitates for cost control, especially for innovators products that have enjoyed a lengthy period of exclusive use. As the first wave of biopharmaceuticals is expired or set to expire, it has led to various opportunities for the expansion of bio-similars i.e. copied versions of original biologics with same biologic activity. Development of biosimilars is expected to promote market competition, meet worldwide demand, sustain the healthcare systems and maintain the incentives for innovation. Methods: Appraisal of published articles from peer reviewed journals, PubMed literature, latest news and guidelines from European Medicine Agency, US Food Drug Administration (FDA) and India are used to identify data for review. Results: Main insight into the quality requirements concerning biologics, current status of regulation of biosimilars and upcoming challenges lying ahead for the upgrading of marketing authorization of bio-similars has been incorporated. Compiled literature on therapeutic status, regulatory guidelines and the emerging trends and opportunities of biosimilars has been thoroughly stated. Conclusion: Updates on biosimilars will support to investigate the possible impact of bio-similars on healthcare market.

LBE for Generalized Hydrodynamics

2018 ◽  
Author(s):  
Sauro Succi
Keyword(s):  
Potential Energy ◽  
Electric Fields ◽  
Chemical Reactions ◽  
Soft Matter ◽  
Fluid Motion ◽  
Life Sciences ◽  
Scientific Discipline ◽  
The Past ◽  
Generalized Hydrodynamics ◽  
Internal Forces

This chapter presents the main techniques to incorporate the effects of external and/or internal forces within the LB formalism. This is a very important task, for it permits us to access a wide body of generalized hydrodynamic applications whereby fluid motion couples to a variety of additional physical aspects, such as gravitational and electric fields, potential energy interactions, chemical reactions and many others. It should be emphasized that while hosting a broader and richer phenomenology than “plain” hydrodynamics, generalized hydrodynamics still fits the hydrodynamic picture of weak departure from suitably generalized local equilibria. This class is all but an academic curiosity; for instance, it is central to the fast-growing science of Soft Matter, a scientific discipline which has received an impressive boost in the past decades, under the drive of micro- and nanotechnological developments and major strides in biology and life sciences at large.

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