Chloride and bromide in carbonate rocks in relation to the chemical history of ocean water

1970 ◽  
Vol 7 (6) ◽  
pp. 1539-1551 ◽  
Author(s):  
Harold H. Williams ◽  
Robert C. Harriss
Keyword(s):  
Carbonate Rocks ◽  
Sea Water ◽  
Sedimentary Rocks ◽  
Progressive Increase ◽  
Water Soluble ◽  
Ocean Water ◽  
Crustal Recycling ◽  
The Past ◽  
History Of ◽  
Chemical History

The acid soluble chloride/bromide ratios of 66 limestones and 74 dolomites and the water soluble chloride/bromide ratios of 65 limestones and 42 dolomites were determined for samples from Recent to Precambrian age (2 b.y.). A progressive increase occurs in the chloride/bromide ratio from the Precambrian to Recent and is interpreted as representing an increase in the chloride/bromide ratio of sea water over the past 2 × 109 years. It is postulated that removal of bromine from sea water by sedimentation of bromine-enriched organic matter and crustal recycling of sedimentary rocks is responsible for the increase in the chloride/bromide ratio of sea water.

scholarly journals New measurements of D/H on Mars using EXES aboard SOFIA

2018 ◽  
Vol 612 ◽  
pp. A112 ◽  
Author(s):  
T. Encrenaz ◽  
C. DeWitt ◽  
M. J. Richter ◽  
T. K. Greathouse ◽  
T. Fouchet ◽  
...  
Keyword(s):  
Water Vapor ◽  
Past History ◽  
Ocean Water ◽  
Echelle Spectrograph ◽  
Sources And Sinks ◽  
The Past ◽  
Northern Summer ◽  
History Of ◽  
Water On Mars ◽  
Important Measurement

The global D/H ratio on Mars is an important measurement for understanding the past history of water on Mars; locally, through condensation and sublimation processes, it is a possible tracer of the sources and sinks of water vapor on Mars. Measuring D/H as a function of longitude, latitude and season is necessary for determining the present averaged value of D/H on Mars. Following an earlier measurement in April 2014, we used the Echelon Cross Echelle Spectrograph (EXES) instrument on board the Stratospheric Observatory for Infrared Astronomy (SOFIA) facility to map D/H on Mars on two occasions, on March 24, 2016 (Ls = 127°), and January 24, 2017 (Ls = 304°), by measuring simultaneously the abundances of H2O and HDO in the 1383–1391 cm−1 range (7.2 μm). The D/H disk-integrated values are 4.0 (+0.8, −0.6) × Vienna Standard Mean Ocean Water (VSMOW) and 4.5 (+0.7, −0.6) × VSMOW, respectively, in agreement with our earlier result. The main result of this study is that there is no evidence of strong local variations in the D/H ratio nor for seasonal variations in the global D/H ratio between northern summer and southern summer.

scholarly journals “Palaeoentomology”: A modern journal for a science dealing with the past

2018 ◽  
Vol 1 (1) ◽  
pp. 1 ◽  
Author(s):  
DANY AZAR ◽  
JACEK SZWEDO ◽  
EDMUND JARZEMBOWSKI ◽  
NEAL EVENHUIS ◽  
DIYING HUANG
Keyword(s):  
Sedimentary Rocks ◽  
Fossil Insects ◽  
The Past ◽  
Terrestrial Arthropods ◽  
Invertebrate Paleontology ◽  
Xxist Century ◽  
History Of ◽  
Geological Sciences ◽  
Fossil Resins ◽  
Biological Literature

Palaeoentomology started in the late XVIIIth century, shortly after the 10th edition of Linnaeus’ Systema Naturae (the foundation of modern taxonomy), when papers on the curiosities of insects entombed in fossil resins were published. The beginning of XIXth century (with the growing interest in geological sciences and prehistoric life) witnessed the first attempts to study and describe insects from sedimentary rocks. This discipline then developed during the XIXth and beginning of the XXth centuries; and resulted in some major works and reviews (summarizing the knowledge on fossil insects and other terrestrial arthropods) published in the geological and biological literature. The XXth century was a period of relatively slow but constant development in palaeoentomology, during which the famous “Treatise on invertebrate paleontology: Arthropoda 4. Superclass Hexapoda” (cataloguing the knowledge on fossil insects) was published (Carpenter, 1992). At the beginning of XXIst century, palaeoentomology grew significantly and exponentially; and two major manuals (“History of insects” and “Evolution of the insects”) were published (Rasnitsyn & Quicke, 2002; Grimaldi & Engel, 2005, respectively). These manuals helped to encourage more students and researchers to work on fossil insects and other terrestrial arthropods. 

On The Possibility of an Autonomous History of Modern Southeast Asia

1961 ◽  
Vol 2 (2) ◽  
pp. 73-105 ◽  
Author(s):  
John R. W. Small
Keyword(s):  
Southeast Asia ◽  
Contemporary History ◽  
The Past ◽  
History Of

It is generally accepted that history is an element of culture and the historian a member of society, thus, in Croce's aphorism, that the only true history is contemporary history. It follows from this that when there occur great changes in the contemporary scene, there must also be great changes in historiography, that the vision not merely of the present but also of the past must change.

Stellar Evolution

1962 ◽  
Vol 11 (02) ◽  
pp. 137-143
Author(s):  
M. Schwarzschild
Keyword(s):  
Solar System ◽  
Stellar Evolution ◽  
Space Craft ◽  
New Techniques ◽  
Substantial Body ◽  
Individual Stars ◽  
The Past ◽  
Evolution Of Galaxies ◽  
History Of ◽  
Fast Flow

It is perhaps one of the most important characteristics of the past decade in astronomy that the evolution of some major classes of astronomical objects has become accessible to detailed research. The theory of the evolution of individual stars has developed into a substantial body of quantitative investigations. The evolution of galaxies, particularly of our own, has clearly become a subject for serious research. Even the history of the solar system, this close-by intriguing puzzle, may soon make the transition from being a subject of speculation to being a subject of detailed study in view of the fast flow of new data obtained with new techniques, including space-craft.

A 200-Year History of the Study of Childhood Language Disorders of Unknown Origin: Changes in Terminology

2020 ◽  
Vol 5 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Laurence B. Leonard
Keyword(s):  
Language Impairment ◽  
Specific Language Impairment ◽  
Scientific Literature ◽  
Language Disorder ◽  
Language Disorders ◽  
Unknown Origin ◽  
Developmental Language Disorder ◽  
The Past ◽  
History Of ◽  
The Many

Purpose The current “specific language impairment” and “developmental language disorder” discussion might lead to important changes in how we refer to children with language disorders of unknown origin. The field has seen other changes in terminology. This article reviews many of these changes. Method A literature review of previous clinical labels was conducted, and possible reasons for the changes in labels were identified. Results References to children with significant yet unexplained deficits in language ability have been part of the scientific literature since, at least, the early 1800s. Terms have changed from those with a neurological emphasis to those that do not imply a cause for the language disorder. Diagnostic criteria have become more explicit but have become, at certain points, too narrow to represent the wider range of children with language disorders of unknown origin. Conclusions The field was not well served by the many changes in terminology that have transpired in the past. A new label at this point must be accompanied by strong efforts to recruit its adoption by clinical speech-language pathologists and the general public.

Suicidal Ideation Among Medical Students in Dammam, Saudi Arabia

Crisis ◽  
2020 ◽  
pp. 1-6
Author(s):  
Mohammed Madadin ◽  
Ritesh G. Menezes ◽  
Maha A. Alassaf ◽  
Abdulaziz M. Almulhim ◽  
Mahdi S. Abumadini ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Medical Students ◽  
Suicidal Ideation ◽  
General Health Questionnaire ◽  
Cross Sectional Study ◽  
Eastern Province ◽  
Cross Sectional ◽  
The Past ◽  
Depression Subscale ◽  
History Of

Abstract. Background: Medical students are at high risk of suicidal ideation. Aim: We aimed to obtain information on suicidal ideation among medical students in Dammam located in the Eastern Province of Saudi Arabia. Method: This cross-sectional study was conducted at the College of Medicine affiliated with Imam Abdulrahman Bin Faisal University in the Eastern Province of Saudi Arabia. Suicidal ideation in the past 12 months was assessed based on responses to four questions in the depression subscale of the General Health Questionnaire 28 (GHQ-28). In addition, data were collected to examine the association of suicidal ideation with various factors. Results: We found that 1 in 3 medical students in the study had suicidal ideation in the past 12 months, while around 40% had lifetime suicidal ideation. Suicidal ideation was associated with feelings of parental neglect, history of physical abuse, and dissatisfaction with academic performance. Limitations: The cross-sectional nature of this study limits its ability to determine causality regarding suicidal ideation. Conclusion: These rates are considerably high when compared with rates from studies in other countries around the world. This study provides a reference in the field of suicidology for this region of Saudi Arabia.

Post-Soviet economy development: From the past to the future

2017 ◽  
pp. 5-21 ◽  
Author(s):  
E. Yasin
Keyword(s):  
Present Situation ◽  
Soviet Economy ◽  
Market Reforms ◽  
Democratic Development ◽  
The Past ◽  
Current Period ◽  
The Future ◽  
History Of ◽  
Working Out ◽  
A Current

The article is devoted to major events in the history of the post-Soviet economy, their influence on forming and development of modern Russia. The author considers stages of restructuring, market reforms, transformational crisis, and recovery growth (1999-2011), as well as a current period which started in2011 and is experiencing serious problems. The present situation is analyzed, four possible scenarios are put forward for Russia: “inertia”, “mobilization”, “decisive leap”, “gradual democratic development”. More than 30 experts were questioned in the process of working out the scenarios.

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