scholarly journals Relationship between hydrothermal fluids and microseismic activity on the south-east coast of Milos Island

2001 ◽  
Vol 34 (4) ◽  
pp. 1441
Author(s):  
Ε. ΜΠΑΛΤΑΤΖΗΣ ◽  
Ν. ΔΕΛΗΜΠΑΣΗΣ ◽  
E. VALSAMI-JONES ◽  
Μ. ΠΥΡΛΗ ◽  
Β. BAIER
Keyword(s):  
Chemical Elements ◽  
Aegean Sea ◽  
Geothermal Field ◽  
Hydrothermal Fluids ◽  
The South ◽  
High Enthalpy ◽  
Time Period ◽  
Tectonic Earthquakes ◽  
Microseismic Activity ◽  
Swarm Activity

Milos island belongs to the Greek volcanic arc and is part of a small number of hot spots in the South Aegean Sea. It is an area that stands out for the diversity in volcanic formations and chemical composition of rocks. The island is characterized by the presence of a high enthalpy geothermal field and a non continuous microseismic activity, expressed both by tectonic earthquakes and swarm activity. During the period of our study (May-December 1999), this activity, which was recorded by a small, portable, seismological network has been very small and limited in the SE part of the island. From the chemical analyses performed, no significant alterations in the composition of the hydrothermal fluids was detected, except from slight changes in the content of K, Ca and Li and even smaller changes in Mg and Fe. This fact certainly implies a possible relation between microseismic activity and alterations in the content of various chemical elements, but it still needs further verification, which means that our research should be prolonged for a time period of at least two years

Late quaternary bottom-current activity in the south Aegean Sea reflecting climate-driven dense-water production

2016 ◽  
Vol 375 ◽  
pp. 99-119 ◽  
Author(s):  
Efthymios K. Tripsanas ◽  
Ioannis P. Panagiotopoulos ◽  
Vasilios Lykousis ◽  
Ioannis Morfis ◽  
Aristomenis P. Karageorgis ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Aegean Sea ◽  
Bottom Current ◽  
Water Production ◽  
The South ◽  
Dense Water ◽  
Current Activity

scholarly journals Design and verification of additional filtration for the application of ecological transmission and hydraulic fluids in tractorc

2013 ◽  
Vol 61 (5) ◽  
pp. 1305-1311 ◽  
Author(s):  
Pavel Máchal ◽  
Radoslav Majdan ◽  
Zdenko Tkáč ◽  
Bohuslav Stančík ◽  
Rudolf Abrahám ◽  
...  
Keyword(s):  
Chemical Elements ◽  
Main Role ◽  
Additive Concentration ◽  
Test Operation ◽  
Time Period ◽  
Medium Level ◽  
Agricultural Tractors ◽  
High Level ◽  
And Function

This contribution presents the design and function verification of additional filtration. It is intended for the common transmission and hydraulic oil filling of tractors. The main role of this filtration concept is to ensure a high level of oil cleanness as a condition for the application of ecologic fluids in tractors. The next one is to decrease the wear of lubricated tractor components, the degradation of oil and eventually to extend the interval of oil change. The designed additional filtering is characterized by ease installation through the use of quick couplings and hoses to the external hydraulic circuit. Therefore, the filtration is suitable for various tractor types. Filter element has been designed with the filter ability 1micron and the ability to separate to 0.5 dm3 of water from oil. Function of additional filtration was verified during the 150 engine hours of tractor operation. During this time period the oil contamination was evaluated on the basis of chemical elements content such as Fe, Cu, Si, Al, Ni, Mo and Cr. The additive concentration was evaluated on the basis of chemical elements content such as Ca, P and Zn. During the test operation of tractor the concentration decrease of chemical elements reached the values 25.53 % (Fe), 23.53 % (Si), 25 % (Al) and 5.5 % (Cu). The decrease of additive concentration reached only medium level (6.6 %). Therefore, the designed additional filtration doesn’t remove additives from oil. Based on the evaluation of the content of chemical elements (that representing contamination and additives), we can say that the designed filtering method is suitable for use in agricultural tractors.

scholarly journals Average annual background quantity of chemical elements and organic matter in the streams of the "River" environment flowing into Lake Baikal reservoirs

2020 ◽  
Vol 5 (4) ◽  
pp. 433-447
Author(s):  
Olga Yu. Astrakhantseva ◽  
◽  
Oleg Yu. Palkin ◽  
Keyword(s):  
Organic Matter ◽  
Lake Baikal ◽  
Chemical Elements ◽  
The South ◽  
River Flows ◽  
Chemical Balance ◽  
Biogenic Components ◽  
Annual Amount ◽  
Natural Component

The aim of the article is to assess the average long-term background hydrochemical input of chemical elements and organic matter from the flows of the natural component of the environment "Rivers" flowing into the South, Selenginsky, Middle and North reservoirs of Lake. Baikal. The results of calculation of the average annual amount (g/year) of chemical elements and organic matter (Na+, K+, Ca2+, Mg2+, Al, Si, Mn2+, Feобщ , SO42-, HCO3-, Cl-, NO3-, PO43-, Cr, Cu, Cd, Hg, Pb, Sr, Zn, Co, U, V, Mo, Cорг, Nорг, Pорг, Sорг, CO2, Ti) in the streams of the natural component of the environment "Rivers" flowing into the South, Selenginsky, Sredniy, Severny reservoirs of Lake Baikal are presented. The scale of the river chemical input into the reservoirs and the contribution of the "River" flows to the chemical balances of these reservoirs have been determined. It has been established that only in the Selenga reservoir the rivers carry a significant amount of matter (about 3%). The contribution of river flows to the chemical balance of the reservoir is 3.54; 5.4; 17.5 and 21.5% in the South, Selenga, Middle and North reservoirs, respectively. The rivers flowing into the Selenga reservoir carry 70.6% of the total amount of matter brought by the rivers into the lake. Whereas the rivers of the Northern, Middle and Southern reservoirs carry 14.0; 11.6 and 3.8% of the matter. Only in the Selenga and Northern reservoirs, the rivers (tributaries) are the main sources of macrocomponents (K+, Na+, Ca2+, SO42-, CO3-, Cl-), a number of microcomponents (Rb, Mo, Hg, Sr, and Cu and Zn in the Selenga river-), organic matter (Corgг, Norg, Porg), and biogenic components in the Selenga reservoir (NO3-).

scholarly journals Key Environmental Factors Controlling Planktonic Foraminiferal and Pteropod Community’s Response to Late Quaternary Hydroclimate Changes in the South Aegean Sea (Eastern Mediterranean)

2020 ◽  
Vol 8 (9) ◽  
pp. 709
Author(s):  
Christina Giamali ◽  
George Kontakiotis ◽  
Efterpi Koskeridou ◽  
Chryssanthi Ioakim ◽  
Assimina Antonarakou
Keyword(s):  
Environmental Factors ◽  
Environmental Changes ◽  
Late Quaternary ◽  
Eastern Mediterranean ◽  
Planktonic Foraminifera ◽  
Explanatory Power ◽  
Principal Component ◽  
Aegean Sea ◽  
Late Glacial ◽  
The South

A multidisciplinary study was conducted in order to investigate the environmental factors affecting the planktonic foraminiferal and pteropod communities of the south Aegean Sea. Aspects of the Late Quaternary paleoceanographic evolution were revealed by means of quantitative analyses of planktonic foraminiferal and pteropod assemblages (including multivariate statistical approach; principal component analysis (PCA)), the oxygen (δ18O) and carbon (δ13C) isotopic composition of planktonic foraminifera and related paleoceanographic (planktonic paleoclimatic curve (PPC), productivity (E-index), stratification (S-index), seasonality) indices, extracted by the gravity core KIM-2A derived from the submarine area between Kimolos and Sifnos islands. Focusing on the last ~21 calibrated thousands of years before present (ka BP), cold and eutrophicated conditions were identified during the Late Glacial period (21.1–15.7 ka BP) and were followed by warmer and wetter conditions during the deglaciation phase. The beginning of the Holocene was marked by a climatic amelioration and increased seasonality. The more pronounced environmental changes were identified during the deposition of the sapropel sublayers S1a (9.4–7.7 ka BP) and S1b (6.9–6.4 ka BP), with extremely warm and stratified conditions. Pteropod fauna during the sapropel deposition were recorded for the first time in the south Aegean Sea, suggesting arid conditions towards the end of S1a. Besides sea surface temperature (SST), which shows the highest explanatory power for the distribution of the analyzed fauna, water column stratification, primary productivity, and seasonality also control their communities during the Late Quaternary.

scholarly journals TRENDS IN PEDIATRIC ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: A REVIEW OF SURGEON FELLOWSHIP, GEOGRAPHY, AND MENISCUS SURGERY IN THE ABOS PART 2 DATABASE

2019 ◽  
Vol 7 (3_suppl) ◽  
pp. 2325967119S0007
Author(s):  
Henry B. Ellis ◽  
Curtis VandenBerg ◽  
Jennifer Beck ◽  
Andrew Pennock ◽  
Aristides I. Cruz ◽  
...  
Keyword(s):  
Geographic Variation ◽  
Acl Reconstruction ◽  
Sports Medicine ◽  
Cruciate Ligament ◽  
Young Patients ◽  
Meniscal Repair ◽  
Fellowship Training ◽  
Geographic Region ◽  
The South ◽  
Time Period

INTRODUCTION: An increased rate of pediatric and adolescent patients undergoing ACL reconstruction has clearly been established, and now considered one of the most common arthroscopic procedures performed in youth patients. Little knowledge exists on whether these trends truly represent an increase in ACL injury, identification, or surgical management. Trends, including surgeon training, meniscus treatment, or geographic differences, have not been reported. The purpose of this study was to review data from ACL reconstructions performed in patients under the age of 17 years, that were submitted to the American Board of Orthopaedic Surgeons (ABOS) Part 2 examination, with a goal of evaluating national treatment trends over a 16-year period. METHODS: A query to the ABOS SCRIBE database was submitted for all ACL reconstructions performed in patients less than 17 years old between 2002 and 2016. The query was designed to search for CPT procedure codes submitted by each applicant. Query data included geographic region, fellowship training of the applicant, age and sex of the patients, and associated procedures. Each case had an associated applicant number, and thus, the total number of ACL reconstructions performed by each surgeon during board collection was provided. Trends were reviewed for the aggregate data and a Mann-Whitney test was used for comparison of data between 2002 – 2009 (Early-ACL) and 2010-2016 (Recent-ACL) groups. RESULTS: Since 2002, there has been a 2.6% increase in pediatric ACL reconstructions performed by candidates applying for Part 2 of the ABOS examination. Additionally, a 193% increase in dual pediatric and sports medicine fellowship trained candidates performing pediatric ACL reconstruction since 2010 was seen. A majority of pediatric ACL procedures were performed by sports medicine trained surgeons (75.9%). During this time period, a total of 362 (or 8.3%) of pediatric ACL procedures were performed by surgeons with neither sports medicine nor pediatric orthopaedic fellowship training. Following 2009, a 44% increase in pediatric ACL reconstructions performed was noted (Figure 1A). Additionally, an increase in reconstructions performed in female patients compared to males was noted (Figure 1B). A majority of pediatric ACL reconstructions did not require additional meniscal treatment, however, meniscus repair was more likely to be performed after 2009 (p=0.0012). The number of meniscal repair procedures reported in the setting of ACL reconstruction generally increased over the study period. In 2002, 24% of ACL reconstructions required a meniscal repair compared to 41% in 2016 (Figure 1C). A majority of these repairs were performed by surgeons with sports medicine fellowship training. Geographic trends reported are based on patients <16 per available census records (Figure 1D). Geographic variation exists with of the highest rates of pediatric ACL reconstructions occurring in the South (4.62 per million) and Midwest (4.07 per million) in comparison to the Southeast (1.85 per million). When adjusting for population size per year, each region saw a significant increase in reported ACL surgeries from the Early-ACL to the Recent-ACL timeframe (p=0.005). The largest increases in surgeries reported between Early-ACL and Recent-ACL were seen in the Southeast (68% increase), Midwest (50% increase) and Southwest (47% increase). Of all the providers who performed surgery, 74% submitted only 1-2 cases from 2002-2016, with 26% of providers performing more than 55% of all of the pediatric ACL reconstruction cases. More than 75% of all cases were performed by sports medicine fellowship trained surgeons However, a large change was seen in dual sports and pediatric trained surgeon case volumes over this time period, with these surgeons performing 7.5 times more surgeries from 2010 to 2016 (Recent-ACL) when compared to 2002-2009 (Early-ACL). CONCLUSION: Since 2009, pediatric ACL reconstructions are more likely to be female and are more likely to undergo a meniscal repair. Geographic variation is noticeable, with more surgeries reported to be performed in the South. Dual pediatric and sports medicine fellowship trained candidates performing ACL reconstruction have significantly increased over time, although those surgeons who are only sports medicine fellowship trained continue to perform the bulk of ACL reconstructions in young patients.

scholarly journals Chemical and isotopic characterization of the thermal fluids emerging along the North–Northeastern Greece

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
E. Dotsika ◽  
P. Dalampakis ◽  
E. Spyridonos ◽  
G. Diamantopoulos ◽  
P. Karalis ◽  
...  
Keyword(s):  
Geothermal Field ◽  
Chemical Compositions ◽  
Geothermal Systems ◽  
High Enthalpy ◽  
Thermal Fluids ◽  
The North ◽  
Geothermal Fields ◽  
West Part ◽  
Distinct Source ◽  
Isotopic Characterization

AbstractHydrochemical and isotopic characteristics of fluids from major geothermal fields of middle/low temperature in N/NE Greece are examined [basins: Strymon River (SR), Nestos River Delta (ND), Xanthi–Komotini (XK), Loutros–Feres–Soufli (LFS) and Rhodope Massif]. The geodynamic context is reflected to isotopic/chemical composition of fluids, heat flow values and elevated CO2 concentrations in emitted fluids. B and Li are derived from leaching of the geothermal systems hosting rocks. δ18OH2O, δ18OSO4, δ13CCO2 values and chemical compositions of Cl, B and Li of geothermal discharges suggest two distinct source fluids. Fluids in SR exhibit high B/Cl and Li/Cl ratios, suggesting these constituents are derived from associated magmas of intermediate composition (andesitic rocks). Geothermal discharges in LFS exhibit low B/Cl and Li/Cl ratios, implying acid (rhyolitic) magmatism. δ13CCO2 and CO2/(CO2 + 105He) ratios in the west part, suggest fluids affected by addition of volatiles released from subducted marine sediments. For the eastern systems, these ratios suggest gas encountered in systems issued from mixing of crustal and mantle-derived volatiles. Isotopic geothermometers reflect, for the same direction, equilibrium processes more (LFS, XK) or less (SR) pronounced and discriminate the geothermal field from low to middle [SR, ND (Erasmio)] and middle to high enthalpy [ND (Eratino), LFS, XK].

Dynamical implications of seasonal and spatial variations in Titan's stratospheric composition

2008 ◽  
Vol 367 (1889) ◽  
pp. 697-711 ◽  
Author(s):  
Nicholas A Teanby ◽  
Patrick G.J Irwin ◽  
Remco de Kok ◽  
Conor A Nixon
Keyword(s):  
Polar Vortex ◽  
Spatial Variations ◽  
The South ◽  
Trace Species ◽  
Time Period ◽  
Circulation Cell ◽  
Seasonal And Spatial Variations ◽  
Infrared Spectrometer ◽  
Stratospheric Circulation ◽  
Stratospheric Composition

Titan's diverse inventory of photochemically produced gases can be used as tracers to probe atmospheric circulation. Since the arrival of the Cassini–Huygens mission in July 2004 it has been possible to map the seasonal and spatial variations of these compounds in great detail. Here, we use 3.5 years of data measured by the Cassini Composite InfraRed Spectrometer instrument to determine spatial and seasonal composition trends, thus providing clues to underlying atmospheric motions. Titan's North Pole (currently in winter) displays enrichment of trace species, implying subsidence is occurring there. This is consistent with the descending branch of a single south-to-north stratospheric circulation cell and a polar vortex. Lack of enrichment in the south over most of the observed time period argues against the presence of any secondary circulation cell in the Southern Polar stratosphere. However, a residual cap of enriched gas was observed over the South Pole early in the mission, which has since completely dissipated. This cap was most probably due to residual build-up from southern winter. These observations provide new and important constraints for models of atmospheric photochemistry and circulation.

A synthesis of the circulation and hydrography of the South Aegean Sea and the Straits of the Cretan Arc (March 1994–January 1995)

1999 ◽  
Vol 44 (4) ◽  
pp. 469-509 ◽  
Author(s):  
Alexander Theocharis ◽  
Efstathios Balopoulos ◽  
Soterios Kioroglou ◽  
Harilaos Kontoyiannis ◽  
Athanassia Iona
Keyword(s):  
Aegean Sea ◽  
The South

Emplacement of the Miocene west Naxos pluton (Aegean Sea, Greece): a structural study

2003 ◽  
Vol 140 (1) ◽  
pp. 45-61 ◽  
Author(s):  
IOANNIS K. KOUKOUVELAS ◽  
SOTIRIOS KOKKALAS
Keyword(s):  
Aegean Sea ◽  
Biotite Granite ◽  
Distribution Analysis ◽  
Block Rotation ◽  
The South ◽  
Mafic Enclaves ◽  
The North ◽  
Divergent Flow ◽  
Regional Deformation ◽  
Fry Method

Synmagmatic and solid-state structures within the Naxos pluton and its rim may provide insight into the interplay between plutonism and regional deformation at upper-crustal level. Within the hornblende–biotite granite of western Naxos, synmagmatic foliations display two distinct patterns, onion-skin in the north and tangential to the rim in the south. The two areas are separated by the NE-trending Glinadon fault. Deformed mafic enclaves in the pluton are prolate, with their long axes parallel to the synmagmatic lineation. In contrast, phenocryst distribution analysis, using the Fry method, defines an apparent oblate strain with a horizontal stretching lineation. Planar markers within the pluton progressively steepen through the vertical at the east pluton border. Several lines of evidence, such as dykes intruding axial areas of rim-parallel folds, foliated or folded aplite veins, folds and spaced cleavage in the mollase, and inverted stratigraphy, suggest pluton emplacement and deformation during transpressional deformation. A northward divergent flow regime with magma spreading out mainly from the Naxos fault, and the deflection of both the synmagmatic foliation pattern and the flow lines at the Glinadon fault, suggest that the NE–SW- and N–S-trending faults were active during pluton formation. In the south the pluton has grown by the expansion of dykes occupying P-shear positions with respect with the Naxos fault; in the north a piecemeal block down-drop complements this process and favours voluminous magma concentration. During the late evolutionary stages of pluton construction, the magma chamber was compartmentalized into NE-trending sectors affected by block rotation in an anticlockwise manner. Understanding the role of faults in the emplacement of the Naxos pluton is important for understanding emplacement of other plutons in the Aegean Sea region, since most of them are controlled by N–S- (Ikaria pluton) or NE- (Tinos, Serifos and Delos plutons) trending faults.

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