scholarly journals Chronology and complex volcanic processes during the 2002-2003 flank eruption at Stromboli volcano (Italy) reconstructed from direct observations and surveys with a handheld thermal camera

2005 ◽  
Vol 110 (B2) ◽  
Author(s):  
Sonia Calvari ◽  
Letizia Spampinato ◽  
Luigi Lodato ◽  
Andrew J. L. Harris ◽  
Matthew R. Patrick ◽  
...  
Keyword(s):  
Flank Eruption ◽  
Stromboli Volcano ◽  
Thermal Camera ◽  
Direct Observations ◽  
Volcanic Processes

Newly discovered submarine flank eruption at Stromboli volcano (Aeolian Islands, Italy)

2008 ◽  
Vol 35 (16) ◽  
Author(s):  
A. Di Roberto ◽  
A. Bertagnini ◽  
M. Pompilio ◽  
F. Gamberi ◽  
M. P. Marani ◽  
...  
Keyword(s):  
Flank Eruption ◽  
Stromboli Volcano ◽  
Aeolian Islands

Interpretation of data from the monitoring thermal camera of Stromboli volcano (Aeolian Islands, Italy)

2009 ◽  
Vol 146 (4) ◽  
pp. 591-601 ◽  
Author(s):  
V. ZANON ◽  
M. NERI ◽  
E. PECORA
Keyword(s):  
Low Temperatures ◽  
Explosive Activity ◽  
Stromboli Volcano ◽  
Thermal Camera ◽  
Thermal Monitoring ◽  
Rock Falls ◽  
Hot Gas ◽  
Summit Area ◽  
Monitoring Camera ◽  
Possible Cause

AbstractTwenty eruptive events from the Northeast Crater of Stromboli volcano recorded by a thermal monitoring camera in early 2004 were analysed in order to understand the eruptive dynamics. Selected events were chosen to be typical of explosions that characterize the steady activity of Stromboli in terms of jet height and duration. Most of the explosions consisted of clast-rich single bursts, originating from the same vent inside the Northeast Crater. Conspicuous ash emission was scarce. Eruptions were preceded by the flashing of a perturbation wave characterized by low temperatures and an average propagation velocity of about 35–100 m s−1. This perturbation was thought to be caused by the bursting of the gas slug at the bottom of the crater and is interpreted as an air wave. This was immediately followed by the expansion of a jet of ‘hot’ gas and particles, at a velocity of 35–75 m s−1. Ejecta coarser than 138 cm appeared ~1.6–2 s after the onset of the explosion, moving at a variable velocity (30–60 m s−1). Eruptive events were either vertical or inclined 7–13° towards the NNW. This inclination is thought to be a consequence either of the morphology of the conduit, following modest rock falls that partially obstructed the uppermost part of the crater, or of the displacement of the internal conduit due to the explosive activity of the volcano. The instability of the summit area is a further possible cause of the deformation of the conduit.

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

Metallurgical Effects of Grain Boundary Ledges

1977 ◽  
Vol 35 ◽  
pp. 126-129
Author(s):  
L.E. Murr
Keyword(s):  
Grain Boundary ◽  
Quantitative Data ◽  
Mechanical Treatment ◽  
Unit Length ◽  
Physical And Mechanical Properties ◽  
Direct Observations ◽  
Transmission Electron ◽  
Properties Of Materials ◽  
Thermo Mechanical Treatment ◽  
Ledge Density

Ledges in grain boundaries can be identified by their characteristic contrast features (straight, black-white lines) distinct from those of lattice dislocations, for example1,2 [see Fig. 1(a) and (b)]. Simple contrast rules as pointed out by Murr and Venkatesh2, can be established so that ledges may be recognized with come confidence, and the number of ledges per unit length of grain boundary (referred to as the ledge density, m) measured by direct observations in the transmission electron microscope. Such measurements can then give rise to quantitative data which can be used to provide evidence for the influence of ledges on the physical and mechanical properties of materials.It has been shown that ledge density can be systematically altered in some metals by thermo-mechanical treatment3,4.

Direct Observations of the Epitaxial Growth of Sputtered Ag on Si

1973 ◽  
Vol 31 ◽  
pp. 122-123
Author(s):  
J. S. Maa ◽  
Thos. E. Hutchinson
Keyword(s):  
Epitaxial Growth ◽  
Film Growth ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Microscopy Technique ◽  
Direct Observations ◽  
In Situ Electron Microscopy ◽  
Beam Sputtering ◽  
The Subject

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.

Void-Lattice Formation in Natural Fluorite by Electron Irradiation

1976 ◽  
Vol 34 ◽  
pp. 614-615 ◽  
Author(s):  
L.E. Murr
Keyword(s):  
Electron Microscope ◽  
Electron Irradiation ◽  
Heavy Ion ◽  
High Energy ◽  
Stoichiometric Ratio ◽  
Direct Observations ◽  
Transmission Electron ◽  
Anion Vacancies ◽  
Cation And Anion Vacancies ◽  
Lattice Formation

The production of void lattices in metals as a result of displacement damage associated with high energy and heavy ion bombardment is now well documented. More recently, Murr has shown that a void lattice can be developed in natural (colored) fluorites observed in the transmission electron microscope. These were the first observations of a void lattice in an irradiated nonmetal, and the first, direct observations of color-center aggregates. Clinard, et al. have also recently observed a void lattice (described as a high density of aligned "pores") in neutron irradiated Al2O3 and Y2O3. In this latter work, itwas pointed out that in order that a cavity be formed,a near-stoichiometric ratio of cation and anion vacancies must aggregate. It was reasoned that two other alternatives to explain the pores were cation metal colloids and highpressure anion gas bubbles.Evans has proposed that void lattices result from the presence of a pre-existing impurity lattice, and predicted that the formation of a void lattice should restrict swelling in irradiated materials because it represents a state of saturation.

Direct observation of Fe-Al-Zn ternary intermetallic compound and its transformation during the early stage of hot-dip galvanizing

1993 ◽  
Vol 51 ◽  
pp. 1116-1117
Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii
Keyword(s):  
Intermetallic Compound ◽  
Reaction Rate ◽  
Diffusion Rate ◽  
Early Stage ◽  
Zinc Bath ◽  
Steel Sheets ◽  
Direct Observations ◽  
Solid Iron ◽  
Iron And Zinc ◽  
Ternary Intermetallic Compound

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.

Pengaruh Modal Sosial Terhadap Perkembangan Pariwisata di Kepulauan Riau

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Nurul Nadjmi
Keyword(s):  
Social Capital ◽  
Qualitative Research ◽  
System Approach ◽  
Research Method ◽  
Analytic Approach ◽  
Community Groups ◽  
Study Strategy ◽  
Direct Observations ◽  
Descriptive Qualitative

Kepulauan Riau merupakan provinsi yang terdiri dari beberapa pulau diantaranya Pulau Batam, Pulau Bintan dan Pulau Karimun. Modal sosial merupakan serangkaian nilai dan norma informal yang dimiliki oleh kelompok masyarat dalam membagun kerjasamanya. Lingkup penelitian pada pembahasan ini adalah terfokus pada pengaruh modal sosial terhadap perkembangan pariwisata di Kepulauan Riau dalam hal ini Pulau Batam, Pulau Bintan, dan Pulau Karimun. Metode penelitian yang digunakan dalam penelitian ini adalah penelitian deskriptif kualitatif. Penelitian ini dikondisikan sebagai penelitian kualitatif melalui strategi studi kasus. Sistem pendekatan yang digunakan juga merupakan pendekatan deskriptif analitik. Melakukan pengamatan langsung, mengumpulkan data-data kemudian menghubungkannya dengan kajian teori yang digunakan. Lokus penelitian ini terdapat di Kepulauan Riau dengan melihat pengaruh modal sosial pada perkembangan pariwisata di ketiga pulau yaitu Pulau Batam, Pulau Bintan dan Pulau Karimun. Berdasarkan hasil survey yang saya lakukan di Kepulauan Riau, terutama pada ketiga pulau yaitu Pulau Batam, Pulau Bintan, dan Pulau Karimun, dari ketiga pulau tersebut ternyata pada Pulau Karimun perkembangan pariwisatanya tidak terlalu berkembang karena masyarakat yang tidak menerima adanya wisatawan terutama wisatawan mancanegara. Riau Islands is a province consisting of several islands including Batam Island, Bintan Island and Karimun Island. Social capital is a set of informal values ​​and norms that are owned by community groups in building cooperation. The scope of research in this discussion is focused on the influence of social capital on the development of tourism in the Riau Islands, in this case Batam Island, Bintan Island, and Karimun Island. The research method used in this research is descriptive qualitative research. This research is conditioned as qualitative research through a case study strategy. The system approach used is also a descriptive analytic approach. Make direct observations, collect data and then relate it to the study of the theories used. The locus of this research is in the Riau Islands by looking at the influence of social capital on the development of tourism in the three islands, namely Batam Island, Bintan Island and Karimun Island. Based on the results of a survey I conducted in the Riau Islands, especially on the three islands, namely Batam Island, Bintan Island, and Karimun Island, of the three islands, it turns out that on Karimun Island the development of tourism is not very developed because people do not accept tourists, especially foreign tourists.

Financial Management of Tires Retail and Restaurant Business in Greater Jakarta

2019 ◽  
Vol 2 (4) ◽  
pp. 267-275
Author(s):  
Sung Suk Kim ◽  
Jacob Donald Tan ◽  
Rita Juliana ◽  
John Tampil Purba
Keyword(s):  
Financial Management ◽  
Management Practices ◽  
Working Capital ◽  
Structured Interviews ◽  
Short Term ◽  
Direct Observations ◽  
Medium Enterprises ◽  
Cash Reserves ◽  
Retained Earnings ◽  
Computerized System

This study aims to explore the financial management practices ofsmall-and-medium-enterprises (SMEs) in the Greater Jakarta (Jabodetabek). We investigate into 3 SME cases by conducting the semi-structured interviews with the owner-managers and using direct observations to know the practices of financial management of SMEs. Through the research, we have found six propositions related to the practice of short-term financial management. They apply bootstraps to ensure availability of working capital. They set aside cash reserves from retained earnings and minimize loans from financial institutions. They have the computerized system to track receivables facilitating working capital needs. They keep theirinventory control efficient to manage working capital. They screen customers using transactional records and reputations to minimize the risk of bad debts.

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