scholarly journals Evidence of high Sr/Ca in a Middle Jurassic murolith coccolith species

2020 ◽  
Author(s):  
Baptiste Suchéras-Marx ◽  
Fabienne Giraud ◽  
Alexandre Simionovici ◽  
Rémi Tucoulou ◽  
Isabelle Daniel
Keyword(s):  
Fluorescence Spectroscopy ◽  
Middle Jurassic ◽  
Photic Zone ◽  
X Ray ◽  
Continuous Record ◽  
The Common ◽  
Geochemical Analyses ◽  
Set Up ◽  
The Impact ◽  
Very High

Paleoceanographical reconstructions are often based on microfossil geochemical analyses. Coccoliths are the most ancient, abundant and continuous record of pelagic photic zone calcite producer organisms. Hence, they could be valuable substrates for geochemically based paleoenvironmental reconstructions but only Sr/Ca is exploited even if it remains poorly understood. For example, some murolith coccoliths species have very high Sr/Ca compared to the common 1-4 mmol/mol recorded in placolith coccoliths. In this study, we analyzed the elemental composition of the Middle Jurassic murolith Crepidolithus crassus by synchrotron-based nanoXRF (X-ray Fluorescence Spectroscopy) mapping focusing on Sr/Ca and compared the record to two placolith species, namely Watznaueria contracta and Discorhabdus striatus. In C. crassus, Sr/Ca is more than ten times higher than in both placoliths and seems higher in the proximal cycle. By comparison with the placoliths analyzed in the same analytical set-up and from the same sample, we exclude the impact of the diagenesis and seawater Sr/Ca to explain the high Sr/Ca in C. crassus. Based on comparisons to Pontosphaera discopora and Scyphosphaera apsteinii which also have high Sr/Ca, it seems more likely that high Sr/Ca in C. crassus is either due to the vertical elongation of the R-units of the proximal cycle or related to the action of the special polysaccharide controlling the growth of those vertically elongated R-units that may have affinities to Sr2+. In order to apply the Sr/Ca proxy to muroliths, further investigations are needed on cultured coccoliths.

scholarly journals Influence of Fluorine on Clinker burnability and mechanical properties of CPA Moroccan cement

2018 ◽  
Vol 149 ◽  
pp. 01075 ◽  
Author(s):  
A. Bouregba ◽  
A. Diouri ◽  
B. Elghattas ◽  
A. Boukhari ◽  
T. Guedira
Keyword(s):  
Mechanical Properties ◽  
Fluorescence Spectroscopy ◽  
Calcium Fluoride ◽  
X Ray Diffraction ◽  
Free Lime ◽  
X Ray ◽  
The Subject ◽  
Lower Temperature ◽  
The Impact ◽  
Cement Raw Mix

It has been found that the addition of certain components, despite their low concentration in raw mix, may accelerate and enhance the reactivity of the cement raw mix. The utilization of mineralizers to facilitate and quicken the process of clinkerization backpedals numerous years, the concept of using such mineralizers to burn normal raw mixes at a much lower temperature with the end goal of decreasing the fuel necessities of the furnace and to enhance the cement proprieties has become to be seriously considered over the most recent couple of years. The subject of this paper is to investigate the impact of calcium fluoride as mineralizer on addition during the clinkerization process of industrial raw mixtures and its effect on chemical, mineralogical, and mechanical properties of CPA Moroccan cement. Five different raw meals were utilized and were burned with 2% of calcium fluoride. The resulting clinker was analyzed by X-ray diffraction (XRD) and fluorescence spectroscopy to determine the chemical phases of the obtained clinker, and the mechanical properties of resulting CPA cement were determined. The results show that the addition of 2% of CaF2 to the clinker raw meal induced a decrease in the burning temperature and free lime, while improving the clinker phase formation and the mechanical properties of obtained cement.

scholarly journals Robertsonian translocation in the house mouse: a tale of chromosomal speciation

2015 ◽  
Author(s):  
Silvia Garagna ◽  
Maurizio Zuccotti ◽  
Ernesto Capanna ◽  
Carloalberto Redi
Keyword(s):  
Mus Musculus Domesticus ◽  
Mouse Population ◽  
Chromosomal Races ◽  
Chromosomal Speciation ◽  
Different Populations ◽  
The Common ◽  
Molecular Bases ◽  
The Impact ◽  
Very High ◽  
Alfred Gropp

The subspecies Mus musculus domesticus has a very high chromosome number variability for the presence, in different populations, of different numbers of metacentric chromosomes. These metacentrics are derived by Robertsonian fusion, i.e. the joining of two acro/telocentrics at the centromeres. Since the discovery in 1969 by Alfred Gropp of the first chromosomal variant in an isolated mouse population of the Swiss Poschiavo Valley, more than 100 geographically distinct chromosomal races with metacentrics fixed in homozygosity have been described. The friendship and the common scientific interests among Alfred Gropp, Ernesto Capanna and Maria Gabriella Manfredi Romanini have primed a wealth of studies on the “Robertsonian phenomenon” in this species. These studies have contributed to elucidate i) the molecular bases of metacentric chromosomes formation, ii) the establishment of metacentric races and iii) the impact that chromosome heterozygosities exert on reproductive isolation and speciation.

scholarly journals The Influence of Organizational Culture on Planning as Perceived by Employees in The Hospital

2019 ◽  
Vol 7 (1) ◽  
pp. 1030-1043
Author(s):  
Evangelis Pardede ◽  
WILLIAMS KWASI PEPRAH ◽  
Patience Boatemaa Antwi-Yamoah
Keyword(s):  
Organizational Culture ◽  
Quantitative Research ◽  
Cultural Practices ◽  
Pearson Correlation ◽  
The Philippines ◽  
Significant Difference ◽  
Set Up ◽  
Strongly Agree ◽  
The Impact ◽  
Very High

Introduction: Planning is essential to healthcare institutions.  The first important factor that indicates the effectiveness and efficiency of an organization is planning and the realization of how the vision and mission that have been set up are implemented. However, organizational culture plays a key role in setting a plan for hospitals. It is upon this premises that this study seeks to find the impact of organizational culture on planning as professed by employees in the hospital and the significant difference between sex and age when planning was considered.    Method: This was quantitative research which was designed as descriptive-correlational. The self-constructed instrument was conveniently administered to 108 hospital employees within Laguna in the Philippines to measure their hospital organizational culture and planning. The statistical study treatment was based on SPSS version 23, where Mean and Standard Deviation and Pearson Correlation and t-test were used to analyze the data.    Result: The results revealed that hospital planning was very high, and they strongly agree with the influence of their organizational culture. Furthermore, the study resulted that there is a high correlation between organizational culture and planning. There was a significant difference in sex, however, there was no significant difference in age. The implication is that hospitals must make sure that their firms’ culture supports planning so that they can meet their objectives.  Discussion: The study recommends that hospitals must make sure that their cultural practices support planning. This is among the various ways to achieve hospitals success and make them effective and efficient. 

scholarly journals Reliable Signals Based on Fisher Transform for Algorithmic Trading

2018 ◽  
Vol 11 (1) ◽  
pp. 87-102
Author(s):  
Cristian Păuna
Keyword(s):  
Financial Markets ◽  
Price Volatility ◽  
Trading Strategies ◽  
Algorithmic Trading ◽  
Market Participant ◽  
Trading Systems ◽  
Functional Parameters ◽  
The Common ◽  
Set Up ◽  
Very High

Abstract Trading and investment on financial markets are common activities today. A very high number of investors, companies, public or private funds are buying and selling every day with a single purpose: the profit. The common questions for any market participant are: when to buy, when to sell and when is better to stay away from the market risk. In order to answer all these questions, many trading strategies are used to establish the best moments to entry or to exit the trades. Due to the large price volatility, a significant part of the trades is set up automatically today by computers using algorithmic trading procedures. For this particular field, special aspects must be met in order to automate the trading process. This paper presents one of these mathematical models used in automated trading systems, a method based on the Fisher transform. A general form of this method will be presented, the functional parameters and the way to optimize them in order to reduce the risk. It will be also suggested a method to build reliable trading signals with the Fisher function in order to be automated. Three different trading signal types will be explained together with the significance of the functional parameters in the price field. A code sample will be included in this paper to prove the simplicity of this method. Real results obtained with the Fisher trading signals will be also presented, compared and analyzed in order to show how this method can be implemented in algorithmic trading.

Experimental Study on Controlled Impact Effect in Plastic Deformation Processes

2013 ◽  
Vol 772 ◽  
pp. 3-8
Author(s):  
Todor Penchev ◽  
Dimitar Karastojanov ◽  
Ivan Altaparmakov
Keyword(s):  
Experimental Study ◽  
Plastic Deformation ◽  
Rocket Engine ◽  
Free Fall ◽  
Impact Deformation ◽  
Deformation Processes ◽  
The Common ◽  
Set Up ◽  
The Impact ◽  
Impact Experiments

Controlled impact may be done if the source of additional force is placed on one of the impact bodies and this force is acting during the impact time. The use of Industrial Rocket Engine (IRE), produced in Bulgaria, enables the controlled impact technology. A laboratory set up was created in order to explore the controlled impact. Experiments on plastic deformation of lead specimens were conducted on this devise using controlled impact. An increase of the specimen deformation was obtained compared to the common free-fall impact deformation as well as a decrease of the rebound to zero (we called that a sticking impact). The results obtained make clear that the use of IRE propelled production machines for plastic deformation technologies improve those processes and decrease the production drain.

scholarly journals A fully automated crystallization apparatus for small protein quantities

2021 ◽  
Vol 77 (1) ◽  
Author(s):  
Ryuichi Kato ◽  
Masahiko Hiraki ◽  
Yusuke Yamada ◽  
Mikio Tanabe ◽  
Toshiya Senda
Keyword(s):  
Protein Crystallization ◽  
Diffusion Method ◽  
Cubic Phase ◽  
Web Browser ◽  
X Ray ◽  
X Ray Crystallography ◽  
Membrane Protein Crystallization ◽  
Crystallization Conditions ◽  
Set Up ◽  
Very High

In 2003, a fully automated protein crystallization and monitoring system (PXS) was developed to support the structural genomics projects that were initiated in the early 2000s. In PXS, crystallization plates were automatically set up using the vapor-diffusion method, transferred to incubators and automatically observed according to a pre-set schedule. The captured images of each crystallization drop could be monitored through the internet using a web browser. While the screening throughput of PXS was very high, the demands of users have gradually changed over the ensuing years. To study difficult proteins, it has become important to screen crystallization conditions using small amounts of proteins. Moreover, membrane proteins have become one of the main targets for X-ray crystallography. Therefore, to meet the evolving demands of users, PXS was upgraded to PXS2. In PXS2, the minimum volume of the dispenser is reduced to 0.1 µl to minimize the amount of sample, and the resolution of the captured images is increased to five million pixels in order to observe small crystallization drops in detail. In addition to the 20°C incubators, a 4°C incubator was installed in PXS2 because crystallization results may vary with temperature. To support membrane-protein crystallization, PXS2 includes a procedure for the bicelle method. In addition, the system supports a lipidic cubic phase (LCP) method that uses a film sandwich plate and that was specifically designed for PXS2. These improvements expand the applicability of PXS2, reducing the bottleneck of X-ray protein crystallography.

scholarly journals Investigation of The Distribution and Fe Content of Iron Sand at Wari Ino Beach Tobelo Using Resistivity Method with Werner-Schlumberger Configuration

2020 ◽  
Vol 9 (1) ◽  
pp. 141-160
Author(s):  
Bayu Achil Sadjab ◽  
I Putu Tedy Indrayana ◽  
Steven Iwamony ◽  
Rofiqul Umam
Keyword(s):  
Fluorescence Spectroscopy ◽  
Data Acquisition ◽  
Cross Section ◽  
Distribution Volume ◽  
Geological Data ◽  
X Ray ◽  
Resistivity Method ◽  
Fe Content ◽  
Set Up ◽  
Free Element

This research aimed to investigate the distribution, volume, and concentration of iron sand at Wari Ino Beach Tobelo. The resistivity method with Werner-Schlumberger configuration was applied to investigate the iron sand distribution. The measurements were set-up on 3 lines that run parallel along the coast of Wari Ino Village. The length of each trajectory was 150 meters with a spacing of 10 meters for each electrode. Data acquisition was carried out by using geoelectric instruments to obtain current injection (I) and voltage (V). The analysis was carried out by using RES2DINV and ROCKWORK software to obtain 2-D and 3-D cross-section models for interpreting the distribution and volume of the iron sand. The analysis and interpretation were supported by geological data of the location. Furthermore, the Fe content was characterized by using X-Ray Fluorescence Spectroscopy (XRF). There results show that the volume of the iron sand in each trajectory was 109,355 m3; 180,254 m3; and 120,556 m3. The total volume of iron sand along the three trajectories was up to 405,335 m3. The Fe content in the form of a free element is 67.41%, 57.12%, and 73.40%. The Fe content in the form of hematite mineral (Fe2O3) was 57.92%, 45.82%, and 65.47%.

scholarly journals Experience with Imaging by Using of Microfocus X-Ray Source

2010 ◽  
Vol 61 (5) ◽  
pp. 287-290 ◽  
Author(s):  
Zdenko Zápražný ◽  
Dušan Korytár ◽  
František Dubecký ◽  
Vladimír Áč ◽  
Zbigniew Stachura ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Phase Contrast ◽  
Ccd Camera ◽  
X Ray ◽  
X Ray Imaging ◽  
Radiation Sources ◽  
Set Up ◽  
High Level ◽  
Very High

Experience with Imaging by Using of Microfocus X-Ray SourceIn this paper we present the current work and experience with using microfocus x-ray generator and commercial CCD camera for x-ray imaging purpose. There is a need in laboratories for the development of imaging methods approaching synchrotron radiation sources, where the brilliance of radiation is on very high-level. Generally, there is no continuous access to synchrotron facilities. Several synchrotron radiation laboratories allocate the access via a proposal system. Thus the time for synchrotron radiation experiments seldom exceeds more than 1-2 weeks per year, which restricts its application to a few selected experiments. Even in future, the routine characterization of samples will be performed mainly at the experimenters home laboratories [10]. In this contribution we show that with the present set-up it is possible to achieve the spatial resolution down to μm and with the appropriate geometry a phase contrast images are observable.

36. Theory of Stellar Atmospheres (Theorie Des Atmospheres Stellaires)

1988 ◽  
Vol 20 (01) ◽  
pp. 493-507
Author(s):  
K. Kodaira ◽  
D.F. Gray ◽  
J.P. Cassinelli ◽  
L.E. Cram ◽  
B. Gustafsson ◽  
...  
Keyword(s):  
Stellar Evolution ◽  
Circumstellar Matter ◽  
Stellar Atmospheres ◽  
X Ray ◽  
Giant Stars ◽  
Laboratory Plasmas ◽  
Red Giant ◽  
The Impact ◽  
Chemical Peculiarity ◽  
Very High

Commission 36 acted or acts as a sponsor or a cosponsor of the following Symposia and Colloquia.(l)Symposium No. 122: “Circumstellar Matter”, Heidelberg, FRG (June 1986), (2)Symposium No. 132: “The Impact of Very High S/N Spectroscopy on Stellar Physics”, Paris, France (June 1987), (3)Colloquium No. 95: “Second Conference on Faint Blue Stars”, Tucson, AZ, USA (May 1987), (4)Colloquium No. 102: “UV and X-ray Spectroscopy of Astrophysical and Laboratory Plasmas”, Beaulieu-sur-Mer, France (September 1987), (5) Colloquium No. 106: “Evolution of Peculiar Red Giant Stars”, Bloomington, IN, USA (July 1988), (6)Colloquium No. 108: “Atmospheric Diagnostics of Stellar Evolution: Chemical Peculiarity, Mass Loss and Explosion”, Tokyo, Japan (September 1987).

Aneurysm of the common hepatic artery

2019 ◽  
Vol 22 (6) ◽  
pp. 76-81 ◽  
Author(s):  
V. N. Troyan ◽  
A. N. Riazanova ◽  
T. Yu. Aleksakhina ◽  
Ya. A. Lubashev ◽  
N. P. Morozova ◽  
...  
Keyword(s):  
Hepatic Artery ◽  
Medical Literature ◽  
Magnetic Resonance Tomography ◽  
Duplex Ultrasound ◽  
Common Hepatic Artery ◽  
Intravenous Contrast ◽  
X Ray ◽  
X Ray Computed ◽  
The Common ◽  
Very High

Common hepatic artery aneurism is a rare pathology. Today there are only isolated instances in the world medical literature. The risk of common hepatic artery and celiac arteries aneurism rupture is very high, and it reaches 50%. Mortality as a result of common hepatic artery aneurism rupture is 75%. Most visceral branches of aorta aneurisms occur asymptomatically unless there is a rupture. Diagnostics of common hepatic artery aneurism includes duplex ultrasound, X-ray computed tomography, magnetic resonance tomography with intravenous contrast and angiography. Differential diagnosis of common hepatic artery aneurism is between pancreas space-occupying lesion (pseudocysts) and paragangliomas. The article describes the clinic-diagnostic case of common hepatic artery aneurism.

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