scholarly journals Paroxysms at Stromboli Volcano (Italy): Source, Genesis and Dynamics

2021 ◽  
Vol 9 ◽  
Author(s):  
Nicole Métrich ◽  
Antonella Bertagnini ◽  
Marco Pistolesi
Keyword(s):  
Magma Ascent ◽  
Explosive Eruptions ◽  
Physical Parameters ◽  
Chemical Profiles ◽  
Speed Up ◽  
Triggering Mechanisms ◽  
Magma Flux ◽  
Good Proxy ◽  
Physical And Chemical ◽  
Diffusion Profiles

Deciphering the triggering mechanisms of violent explosive activity is of broad interest for understanding the dynamics of basaltic open-vent volcanic systems. For nearly 1300 years Stromboli has been renowned not only for its continuous degassing activity and mild explosions at the summit craters, but also for short-lived, violent explosive events of variable scale, known as major explosions and paroxysms. Here, we focus on the 1456 and 1930 paroxysms and on the most recent events, in July and August 2019 at Stromboli. We show that shallow phenomena such as flank collapse, lava outpouring through fractures opening, or partial emptying of the shallow conduit, only speed up volatile-rich magma ascent by increasing the decompression rate, whereas pressurization of the crustal system and the deep refilling by magma and its CO2-rich gas phase play a major role in triggering paroxysms. Moreover, we present new data on the geochemistry of the 2019 bulk pumice, along with a compilation of data from the literature, chemical profiles in olivine crystals, and the physical parameters of explosive eruptions of wide ranging magnitude and intensity. For small and large paroxysms, timescales were derived from Fe–Mg diffusion profiles in olivine. In both types of explosion, the last phases of crystallization-diffusion indicate rapid magma ascent rates of two to ten days prior to eruption. Trace element concentrations (Nb, La and Ba) and ratios (Rb/Th) indicate that the 2019 pumice samples plot in the domain of magma batches erupted within the last 20 years at Stromboli. As a whole, there is no correlation between magma geochemistry and magnitude or intensity of explosive eruptions, which span a range of ∼3 orders of magnitude (from major explosions to large paroxysms) based on estimates of erupted tephra volumes. In contrast, olivine compositions are a good proxy for erupted tephra volumes and magma flux. The correlation among physical and chemical parameters, which is valid for the overall spectrum of eruptions, implies that the magmatic source ultimately controls eruptive dynamics.

scholarly journals Kajian kualitas air pada area budidaya kurungan jaring tancap (KJT) di Danau Tutud Desa Tombatu Tiga Kecamatan Tombatu Kabupaten Minahasa Tenggara

2017 ◽  
Vol 5 (1) ◽  
Author(s):  
Christian Tokah ◽  
Suzanne L. Undap ◽  
Sammy N.J. Longdong
Keyword(s):  
Water Quality ◽  
Good Condition ◽  
Laboratory Analysis ◽  
Ex Situ ◽  
Primary Data ◽  
Physical Parameters ◽  
Chemical Parameters ◽  
Research Activities ◽  
Physical And Chemical Parameters ◽  
Physical And Chemical

The aim of this study was to measure and assess the physical and chemical parameters of water quality in the area of ​​fixnet cage cultureat Lake Tutud Tombatu TigaVillagewhich included temperature, pH, DO, TDS, NO3, NO2, NH3 and PO4 in a different time.This research was conducted from August to November 2016. The research activities consisted of direct measurements in the field (in situ) using a Horiba instrument and laboratory analysis (ex situ) at the Agency for Industrial Research and Development Research Institute of Standardization and Industrial Manado. Determination points were done by purposive sampling which refers to the physiographic location wherever possible in order to represent or describe these waters.Water quality measured at4 stations using a Horiba at a depth of 0.5 meters from the bottom of the lake.Station I represented Inlet water, Station II where the cultivation A, Station III where the cultivation B and Station IVwhere no cultivation. The data obtained and collected were primary data i.e., measurement of physical and chemical parameters of water quality as well as watching for signs of sick fish, dead fish, and the growth of farmed fish.The results showed the water temperature ranged between 28-29 ° C, TDS 0266-0412 mg/L and chemical parameters for dissolved oxygen 2-5 mg/L, pH 7-8 and for the results of laboratory analysis, N03(0.7 - 6.3 mg/L), NO2(0001-0002 mg/L), NH3 (0180-1920 mg/L), PO4(0020-0209 mg/L). In general, the existence of water quality of lake Tutud were still in good condition except for NH3 concentrationthat exceeded quality standard limitsof Government Regulation No. 82 of 2001. Basically lake Tutud can still be used for fish farming, but the addition of new cages were not recommended.   Keywords: Lake Tutud,water quality, physical parameters, chemical parameters, fix net cage

scholarly journals Rapid magma ascent recorded by water diffusion profiles in mantle olivine

Geology ◽  
2006 ◽  
Vol 34 (6) ◽  
pp. 429 ◽  
Author(s):  
Sylvie Demouchy ◽  
Steven D. Jacobsen ◽  
Fabrice Gaillard ◽  
Charles R. Stern
Keyword(s):  
Water Diffusion ◽  
Magma Ascent ◽  
Mantle Olivine ◽  
Diffusion Profiles

scholarly journals Decentralized wastewater treatment performance evaluation based on chemical and physical parameters at Bantul Regency, Yogyakarta

2019 ◽  
Vol 280 ◽  
pp. 03006
Author(s):  
Suphia Rahmawati ◽  
Andik Yulianto ◽  
Ahmad Traju Pangentas Wijayaningrat
Keyword(s):  
Wastewater Treatment ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
National Standard ◽  
Physical Parameters ◽  
Chemical Parameters ◽  
Oil And Grease ◽  
Physical And Chemical Parameters ◽  
Simple Technology ◽  
Physical And Chemical

Communal wastewater treatment plant (CWWTP) has been chosen as one system to treat domestic wastewater due to simple technology, flexible management, and cost-effectiveness. There are 376 CWWTP have been recorded by Environmental Agency of Yogyakarta (DLH DIY) that spread in five regencies. Monitoring results on CWWTP effluent showed that some physical and chemical parameters did not meet the domestic wastewater standard. Therefore, evaluation of removal efficiency in terms physical and chemical parameters are necessary. The samples were collected from nine CWWTP in Banguntapan, Bantul and Gamping sub-districts. The physical and chemicals parameters (pH, TSS, BOD, COD, Ammonia, oil, and grease) of influent and effluent from CWWTP are analyzed based on National Standard of Indonesia (SNI) for domestic wastewater. The results show that BOD (>70%) and TSS (>50%) have better removal effectiveness compare with COD, ammonia, oil, and grease (40%). Overall, CWWTP in Banguntapan subdistrict has better performance compare with CWWTP in Bantul subdistrict.

Strong Down-Conversion Emission of Sm3+ Doped Borotellurite Glass under 480 nm Excitation Wavelength

2016 ◽  
Vol 705 ◽  
pp. 204-208
Author(s):  
Siti Nasuha Rafien ◽  
Azman Kasim ◽  
Azhan Hashim ◽  
S. Akmal Syamsyir ◽  
Mardhiah Abdullah ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Emission Spectra ◽  
Ultra Violet ◽  
Luminescence Spectra ◽  
Excitation Wavelength ◽  
Physical Parameters ◽  
Tellurite Glasses ◽  
Physical And Chemical ◽  
Down Conversion ◽  
And Chemical Properties

Tellurite glasses were generally applied in rare earth optical materials due to their excellent in physical and chemical properties. In this study, tellurite glasses composed of (70-x)TeO2-20B2O3-10ZnO-xSm2O3 (x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol %) were prepared by conventional melt-quenching technique. Some basic physical parameters such as density, molar volume and oxygen packing density as well as the optical analysis by mean of their absorption and emission spectra have been carried out at room temperature using UV/Vis and photoluminescence spectrophotometer. The result of physical properties are found to vary with respect to concentration of Sm3+ ions content. Meanwhile, three strong absorption peaks are observed and are well resolved in the ultra violet and visible regions due to transitions between the ground state and various excited state of Sm3+ ions. Under 480nm laser excitation, luminescence spectra exhibit four emission bands at 562 nm, 599 nm, 645 nm and 706 nm which corresponding to the transition 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 were observed. Some other results were also been analysed and presented.

Ultrasonic wave propagation in rare-earth monochalcogenides

Open Physics ◽  
2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Devraj Singh ◽  
Dharmendra Pandey ◽  
Pramod Yadawa
Keyword(s):  
Elastic Constants ◽  
Ultrasonic Attenuation ◽  
Mixed Valence ◽  
Thermal Relaxation ◽  
Coupling Constants ◽  
Physical Parameters ◽  
Acoustic Coupling ◽  
Third Order Elastic Constants ◽  
Ultrasonic Parameters ◽  
Physical And Chemical

AbstractThe ultrasonic attenuation in thulium monochalcogenides TmX (X=S, Se and Te) has been studied theoretically with a modified Mason’s approach in the temperature and range 100 K to 300 K along 〈100〉, 〈110〉 〈111〉 crystallographic directions. The thulium monochalcogenides have attracted a lot of interest due to their complex physical and chemical characteristics. TmS, TmSe and TmTe are trivalent metal, mixed valence state, and divalent semiconductor, respectively. Coulomb and Born-Mayer potential is applied to evaluate the second- and third-order elastic constants. These elastic constants are used to compute ultrasonic parameters such as ultrasonic velocities, thermal relaxation time, and acoustic coupling constants that, in turn, are used to evaluate ultrasonic attenuation. A comparison of calculated ultrasonic parameters with available theoretical/experimental physical parameters gives information about classification of these materials.

scholarly journals ANALISIS PENGEMBANGAN BUDIDAYA RUMPUT LAUT Gracillaria sp DI KECAMATAN SINJAI TIMUR KABUPATEN SINJAI

2021 ◽  
Vol 3 (2) ◽  
pp. 30-33
Author(s):  
Irmawati Malkab ◽  
Hadijah Hadijah ◽  
Sri Mulyani
Keyword(s):  
Water Environment ◽  
Pond Water ◽  
Limiting Factor ◽  
Physical Parameters ◽  
Chemical Physics ◽  
Seaweed Farming ◽  
East Village ◽  
Suitable Site ◽  
Physical And Chemical ◽  
The Village

Kondisi lingkungan perairan tambak terutama dari aspek kualitas fisika dan kimia perairan sangat menentukan keberhasilan budidaya rumput laut gracilaria sp.  Tujuan  penelitian ini adalah menganalisis parameter fisika dan kimia air tambak yang mendukung pengembangan budidaya rumput laut dan penentuan lokasi yang sesuai untuk pengembangan budidaya rumput laut ditinjau dari aspek fisika dan kimia air di empat desa/Kelurahan  Kecamatan Sinjai Timur Kabupaten Sinjai.  Dilaksanakan pada bulan Januari sampai Februari 2016. Teknik analisis dilakukan dengan menentukan beberapa parameter fisika kimia air sebagai faktor pembatas yang terdiri dari: kecerahan, suhu, kedalaman, salinitas, pH, DO,CO2, fosfat, dan nitrat.  Parameter pembatas  dalam empat  kelas kategori, yaitu kelas sangat sesuai, sesuai, kurang sesuai , dan tidak sesuai.  Hasil Penelitian menunjukkan tambak di Kelurahan Samataring, Desa Tongke-tongke, Desa Panaikang, dan Desa Pasimarannu sesuai untuk pengembangan budidaya rumput laut gracillaria sp. Condition pond water environment, especially from the aspect of water quality chemical physics determine the success of seaweed farming gracilaria sp. The purpose of this study was to analyze the physical and chemical parameters of water ponds, which supports the development of seaweed farming and determining a suitable site for the development of seaweed cultivation from the aspect of chemical physics of water in four villages / East Village Sinjai Sinjai district. Conducted in January and February 2016. Technical analysis is done by determining several physical parameters of water chemistry as a limiting factor consisting of: brightness, temperature, depth, salinity, pH, DO, CO2, phosphate, and nitrate. Parameters delimiter in four grade categories, namely class is suitable, appropriate, less appropriate and not appropriate. Research shows ponds in the village of Samataring, Tongke-tongke, Panaikang and pasimarannu appropriate for the cultivation of seaweed gracillaria sp.

scholarly journals Hubungan Keanekaragaman dan Keberadaan Plankton Terhadap Faktor Fisika Kimia Sungai Batanghari

2018 ◽  
Vol 1 (2) ◽  
pp. 55
Author(s):  
Marhadi Marhadi ◽  
Ira Galih Prabasari ◽  
Ria Pratiwi
Keyword(s):  
Water Pollution ◽  
Lead Chloride ◽  
Primary Data ◽  
Physical Parameters ◽  
Strongly Correlated ◽  
Phosphate Nitrate ◽  
Pollutant Level ◽  
Physical And Chemical ◽  
The Relationship

Water pollution can not only be measured only by chemical and physical parameters, Plankton have properties that are always moving so that they can be used as indicators of water pollution. Plankton play an important role in influencing the primary productivity of river waters. The purpose of this study was to determine the relationship between the diversity and presence of plankton to the quality of the Batanghari River. The study was conducted in February 2018 in Jambi City. Primary data taken in the form of concentrations of physical and chemical parameters include turbidity, pH, TDS, BOD, COD, DO, Phosphate, Nitrate, Nitrite, Ammonia, Lead, Chloride, Sulfate and the amount of plankton abundance (ind / L) on the Batanghari River. The time of sampling was in the morning and evening on the same day.  The results showed that the relationship between the existence of plankton and the quality of the Batanghari River showed the condition of the Batanghari River in Jambi City was in phase a - Mesosaprobic (heavy pollutant level). Parameters of pH, COD, Phosphate, Nitrite, Lead and Chloride are moderately correlated to phytoplankton, while TDS, BOD, DO, Nitrate and Ammonia are weakly correlated with phytoplankton. And for temperature parameters it is strongly correlated with phytoplankton. For correlation to zooplankton, parameters of pH, TDS, BOD, COD, COD, DO, Phosphate, Nitrate, Nitrite, Lead, chloride are very weakly correlated while ammonia and turbidity correlate moderately to zooplankton.

scholarly journals PEMAKAIAN FLY-ASH SEBAGAI CEMENTITIOUS PADA BETON MUTU TINGGI DENGAN STEAM CURING (THE USE OF FLY-ASH AS CEMENTITIOUS ON HIGH-STRENGTH CONCRETE WITH STEAM CURING)

2014 ◽  
Vol 10 (2) ◽  
Author(s):  
Erwin Rommel ◽  
Yunan Rusdianto
Keyword(s):  
Fly Ash ◽  
Precast Concrete ◽  
Chemical Properties ◽  
High Strength ◽  
Steam Curing ◽  
Initial Strength ◽  
Speed Up ◽  
Physical And Chemical ◽  
And Chemical Properties

Erwin Rommel1 & Yunan Rusdianto2Jurusan Teknik Sipil Fakultas Teknik Universitas Muhammadiyah MalangAlamat Korespondensi :Jalan Raya Tlogomas 246 Malang 65144email : [email protected] HP 08123314432ABSTRACTThe use of fly-ash as cementitious will be made to utilize physical and chemical properties offly-ash that has a dominan of silica and good of modulus fines. The use of steam curing will be donein this study which can speed up the cycle of making concrete. This is advantageous in the productionof precast concrete and velocity field construction.The research was conducted by making concrete cube 15x15x15 cm for 80 pieces and thentested the compressive strength and absorption of concrete. Achieve the quality of concrete madewith the provision of K600 with giving the fly-ash respectively 7.5%, 15% and 30% by weight ofcement.The results of the research obtained by the use of fly-ash as much as 7.5% as a cementitiousthat was given to the steam curing will provide the initial strength of concrete reached 47% ofcompressive strength at 28 days. While the effect of giving fly-ash in concrete has not seen absorptionsignificantly when compared to concrete without fly-ash.Key word : concrete, fly-ash, steam curing

scholarly journals Machine Learning-Based Multidomain Processing for Texture-Based Image Segmentation and Analysis

2020 ◽  
Author(s):  
Nikolay Borodinov ◽  
Wan-Yu Tsai ◽  
Vladimir V. Korolkov ◽  
Nina Balke ◽  
Sergei Kalinin ◽  
...  
Keyword(s):  
Machine Learning ◽  
Topological Defects ◽  
Physical Parameters ◽  
General Strategy ◽  
Nanoscale Systems ◽  
Force Microscopy ◽  
Atomic Force ◽  
Periodical Structure ◽  
Physical And Chemical ◽  
Selection Of

<a>Atomic and molecular resolved atomic force microscopy (AFM) images </a>offer unique insights into materials properties such as local ordering, molecular orientation and topological defects, which can be used to pinpoint physical and chemical interactions occurring at the surface. Utilizing machine learning for extracting underlying physical parameters increases the throughput of AFM data processing and eliminates inconsistencies intrinsic to manual image analysis thus enabling the creation of reliable frameworks for qualitative and quantitative evaluation of experimental data. Here, we present a robust and scalable approach to the segmentation of AFM images based on flexible pre-selected classification criteria. Usage of supervised learning and feature extraction allows to retain the consideration of specific problem-dependent features (such as types of periodical structure observed in the images and the associated numerical parameters: spacing, orientation, etc.). We highlight the applicability of this approach for segmentation of molecular resolved AFM images based on crystal orientation of observed domains, automated selection of boundaries and collection of relevant statistics. Overall, we outline a general strategy for machine learning-enabled analysis of nanoscale systems exhibiting periodic order that could be applied to any analytical imaging technique.

scholarly journals Numerical investigation of particle motion at the steel—slag interface in continuous casting using VOF method and dynamic overset grids

2022 ◽  
Author(s):  
Xiaomeng Zhang ◽  
Stefan Pirker ◽  
Mahdi Saeedipour
Keyword(s):  
Particle Motion ◽  
Particle System ◽  
Particle Density ◽  
Steel Slag ◽  
Physical Parameters ◽  
Slag Particle ◽  
Dynamic Overset Grids ◽  
Capillary Interactions ◽  
Speed Up ◽  
A Minor

AbstractThe capillary interactions are prominent for a micro-sized particle at the steel—slag interface. In this study, the dynamics of a spherical particle interacting with the steel—slag interface is numerically investigated using the volume of fluid method in combination with the overset grid technique to account for particle motion. The simulations have shown the particle’s separation process at the interface and successfully captured the formation and continuous evolution of a meniscus in the course of particle motion. A sensitivity analysis on the effect of different physical parameters in the steel—slag—particle system is also conducted. The result indicates that the wettability of particle with the slag phase is the main factor affecting particle separation behavior (trapped at the interface or fully separated into slag). Higher interfacial tension of fluid interface and smaller particle size can speed up the particle motion but have less effect on the equilibrium position for particle staying at the interface. In comparison, particle density shows a minor influence when the motion is dominated by the capillary effect. By taking account of the effect of meniscus and capillary forces on a particle, this study provides a more accurate simulation of particle motion in the vicinity of the steel—slag interface and enables further investigation of more complex situations.

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