scholarly journals Depositional Landforming Processes at the Snouts of Five Surging Glaciers in Vestspitsbergen (Abstract only)

1981 ◽  
Vol 2 ◽  
pp. 115-115 ◽  
Author(s):  
D. G. Croot
Keyword(s):  
Simple Model ◽  
Recent Work ◽  
Central Area ◽  
Morphological Features ◽  
Landscape Development ◽  
Maximum Extension ◽  
The Core ◽  
Polar Environment ◽  
Compressive Flow ◽  
Ice Leads

Recent work by Clapperton (1975) proposes that the rapid rates of advance experienced by glaciers which surge may lead to enhanced debris incorporation, increased compressive flow near the glacier snout at the point of maximum extension, and to the upward translation and vertical stacking of debris near the glacier snout and margin. Five glaciers in Spitsbergen (Battyebreen, Holmströmbreen, Lisbetbreen, Vonbreen, Elnabreen) display morphological features which are widely accepted as being diagnostic of surging glaciers.Results of detailed observations regarding the nature, distribution, melt-out, and reworking of englacial debris at Battyebreen are presented. Basally derived till is brought to the surface of the glacier in narrow lateral and terminal belts, no more than 100 m wide. Within this zone, (i.e. up-valley from the snout and towards the valley centre) the ice is debris-free with the exception of small amounts of en-glacial debris which form the core of lobate medial moraines. Differential ablation of debris-free and debris-rich ice leads to the production of a topographic basin within which melt-out and reworking processes occupy restricted locations, as follows. Immediately inside the encircling melt-out till, a zone of flow tills is found. Melt streams are located at the foot of, the flow till-mantled slope, producing narrow (150 m wide) outwash trains, which merge into deltas. The central area of the topographic basin is occupied by a supraglacial lake.Observations of the remaining four locations confirm that other glaciers in the vicinity, which display similar characteristics associated with surging, are developing a stagnant-ice zone of identical appearance. The pattern of processes observed at Battyebreen is thus repeated at each site.A simple model of depositional landscape development is proposed for surging valley glaciers in a sub-polar environment.

Composition of the genus Loricella (Mollusca: Polyplacophora: Loricidae) and the description of two new species

Zootaxa ◽  
2021 ◽  
Vol 4981 (2) ◽  
pp. 275-300
Author(s):  
BORIS SIRENKO
Keyword(s):  
Electron Microscope ◽  
New Species ◽  
Scanning Electron Microscope ◽  
Central Area ◽  
Dorsal Side ◽  
Morphological Features ◽  
Related Genus ◽  
Mouth Region ◽  
Two New Species ◽  
Scanning Electron

The genus chiton Loricella is revised. It comprises nine species. Two of these species, L. neoguinensis n. sp. and L. solomonensis n. sp., are described as new. Based on the analysis of morphological features studied using a scanning electron microscope, a revised diagnosis of the genus is provided. The characters diagnostic for this that distinguish it from the related genus Squamophora are as follows: a tubular hollow inside the dorsal scales, bristles on the dorsal side of the girdle, a wide ventral mouth region, a narrow mantle fold covered with simple longitudinally ribbed scales, smooth ventral scales, pits arranged in longitudinal rows in the central area of the tegmentum, and a bicuspid head of the major lateral teeth of the radula. 

scholarly journals The Depletion of Giants in Globular Clusters

1996 ◽  
Vol 174 ◽  
pp. 355-356 ◽  
Author(s):  
Simon F. Portegies Zwart
Keyword(s):  
Simple Model ◽  
Globular Clusters ◽  
High Density ◽  
Red Giants ◽  
The Core ◽  
Stellar Collisions ◽  
Central Regions

A significant depletion of red giants is observed in the central regions of post-collapsed globulars (Djorgovski et al., 1993) like M 15 (Stetson, 1991). A simple model shows that the depletion of red giants in the high-density cores of globular clusters can be understood in terms of mutual stellar collisions. Slightly outside the core stellar collisions are not frequent enough to explain the reduction in the observed number of red giants.

scholarly journals A Small Step on the Long Road to Understanding the R Stars: CNO Cycling in Candidate R Star Progenitors

2008 ◽  
Vol 25 (4) ◽  
pp. 155-160 ◽  
Author(s):  
G. Angelou ◽  
J. Lattanzio
Keyword(s):  
Recent Work ◽  
White Dwarf ◽  
Carbon Star ◽  
Small Step ◽  
Subsequent Evolution ◽  
The Core ◽  
Merger Event ◽  
Red Giant

AbstractRecent work has proposed that a merger event between a red-giant and a He white dwarf may be responsible for the production of R stars (Izzard, Jeffery & Lattanzio 2007). We investigate the proposed evolution and nucleosynthesis of such a model. We simulate the hypothesized late ignition of the core flash by increasing neutrino losses until ignition occurs sufficiently far from the centre that the subsequent evolution produces carbon dredge-up to the extent that the post-flash object is a carbon star. Detailed nucleosynthesis is performed within this approximation and we show that the overall properties are broadly consistent with the observations. Details will depend on the dynamics of the merger event.

scholarly journals Is It Possible to Determine Whether a Star is Rotating About a Unique Axis?

1993 ◽  
Vol 137 ◽  
pp. 566-568 ◽  
Author(s):  
D.O. Gough ◽  
A.G. Kosovichev
Keyword(s):  
Simple Model ◽  
Angular Velocity ◽  
Rotation Axis ◽  
The Other ◽  
The Sun ◽  
Natural Question ◽  
Rotating Stars ◽  
The Core ◽  
Axis Of Rotation ◽  
Fixed Axis

Rotating stars are normally presumed to rotate about a unique axis. Would it be possible to determine whether or not that presumption is correct? This is a natural question to raise, particularly after the suggestion by T. Bai & P. Sturrock that the core of the sun rotates about an axis that is inclined to the axis of rotation of the envelope.A variation with radius of the direction of the rotation axis would modify the form of rotational splitting of oscillation eigenfrequencies. But so too does a variation with depth and latitude in the magnitude of the angular velocity. One type of variation can mimic the other, and so frequency information alone cannot differentiate between them. What is different, however, is the structure of the eigenfunctions. Therefore, in principle, one might hope to untangle the two phenomena using information about both the frequencies and the amplitudes of the oscillations.We consider a simple model of a star which is divided into two regions, each of which is rotating about a different fixed axis. We enquire whether there are any circumstances under which it might be possible to determine seismologically the separate orientations of the axes.

A new aerophilic species of the genus Diploneis (Bacillariophyta) from the Mawsmai cave of Meghalaya, Northeast India

Phytotaxa ◽  
2020 ◽  
Vol 443 (1) ◽  
pp. 67-78
Author(s):  
CHINTAN BHATT ◽  
BALASUBRAMANIAN KARTHICK
Keyword(s):  
Internal Structure ◽  
Central Area ◽  
Northeast India ◽  
Morphological Features ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

A new aerophilic species, Diploneis mawsmaii sp. nov., is here described from a speleo-environment. The species is found on mosses growing under the water dripping region of Mawsmai cave, Meghalaya state of India. It is discussed based on detailed light and scanning electron microscopic observations and compared with morphologically similar Diploneis species like D. modica Hustedt, D. modicahassiaca Lange-Bertalot & A. Fuhrmann, D. boldtiana Cleve and D. zula Kulikovskiy & Lange Bertalot. Diploneis mawsmaii possesses distinct morphological features such as a largely expanded central area bearing a prominent circular to oval central nodule and the internal structure exhibiting short striation with acute ends and the flattening of longitudinal canals at the central area. This discovery increases our understanding of cavern biodiversity in the Indo-Burma hotspot region.

The Strength of the Centre: Downtown Offices and Metropolitan Decentralization Policy in Toronto

1983 ◽  
Vol 15 (10) ◽  
pp. 1361-1380 ◽  
Author(s):  
W R Code
Keyword(s):  
Central Area ◽  
Theoretical Level ◽  
Quality Of Information ◽  
Subsequent Increase ◽  
Face To Face ◽  
The Core ◽  
Decentralization Policy ◽  
The Difference ◽  
Office Development

Within the context of recent attempts by Toronto to restrict office development in its downtown, the author examines, from several perspectives, the apparent locational conservatism of office activities in the existing core. He begins by arguing that in terms of overall systems efficiency the rationale for the decentralization strategy for Toronto was incomplete and that existing data on the frequencies of face-to-face contact indicated that a substantial increase in the difference between core and suburban rents was necessary to induce a significant removal of office activities from the central area. The subsequent increase in this difference beyond the theoretical level where out-migration should occur suggests the importance of other variables besides those traditionally measured by information linkage studies. Neglected among these factors is the quality of information, reflecting the ability to ‘shop’ among alternative information sources, which in a fundamental sense depends on accessibility. It is suggested that Toronto should not be surprised at increasing resistance to outward movement among the remaining office functions and the consequent higher differences between core and suburban rents, which are necessary to induce decentralization. Finally, through an examination of the origins of demand for suburban office-space in Metropolitan Toronto, the increasing level of resistance to removal by the office functions which remain in the core is shown to be consistent with recent migration trends.

N,N-Dialkyl-N'-Chlorosulfonyl Chloroformamidines in Heterocyclic Synthesis. Part VIII. Novel Pyrazolo-Fused Oxathiadiazines and Thiatriazoles

2010 ◽  
Vol 63 (4) ◽  
pp. 659 ◽  
Author(s):  
Craig M. Forsyth ◽  
Craig L. Francis ◽  
Saba Jahangiri ◽  
Andris J. Liepa ◽  
Michael V. Perkins ◽  
...  
Keyword(s):  
Recent Work ◽  
Major Product ◽  
Ring System ◽  
Heterocyclic Synthesis ◽  
Ring Systems ◽  
The Core ◽  
Derivatives Of

N,N-dialkyl-N′-chlorosulfonyl chloroformamidines 1 reacted with pyrazol-3-ones 2 under a variety of conditions to give pyrazolo[2,3-e][1,2,3,5]oxathiadiazine dioxides 3 and pyrazolo[3,2-b][1,4,3,5]oxathiadiazine dioxides 5, and frequently, one or both of pyrazolo[1,2-b][1,2,3,5]thiatriazole 1,1,5-trioxides 4 and 1,1,7-trioxides 6. In all reactions, the pyrazolo[3,2-b][1,4,3,5]oxathiadiazine 5 was the major product, with the pyrazolo[2,3-e][1,2,3,5]oxathiadiazine 3 being a significant product in the absence of base. Prior to our recent work, the core ring systems of compounds 3 and 5 had not been reported and compounds 4 and 6 are new derivatives of a rare ring system.

scholarly journals Relocation and Livelihood Concerns of Sariska Tiger Project, Rajasthan: A Pride or Plight?

2015 ◽  
Vol 3 (2) ◽  
pp. 72
Author(s):  
Muraree Lal Meena
Keyword(s):  
Task Force ◽  
Central Area ◽  
Panthera Tigris ◽  
Illegal Hunting ◽  
The Core ◽  
The People ◽  
Tiger Reserve ◽  
Peripheral Areas ◽  
The Government

It is well known that Sariska Tiger Reserve is a home to the India’s national animal - the Bengal Tiger (Panthera tigris tigris). The crux of this research is to examine the role of local peoples in the conservation of Sariska Tiger project, which was declared a wildlife reserve way back in 1955 and then further raised to a status of a Tiger Reserve in 1978, and a National Park in 1982. According to the Government officials, the people around the reserve are not only responsible for degrading the reserve, it has also emerged as a safe haven for the poachers involved in illegal hunting of the tigers. One of the reasons identified to be the cause of tiger extinction is the human habitation in the core and in the peripheral areas surrounding the tiger reserves. Despite efforts being made to protect, the Sariska Tiger Reserve, located in Alwar (Rajasthan) is seriously facing the problem of tiger extinction. It is estimated that there are around 12 thousand people residing inside the tiger reserve, with 11 villages in the Core Zone-1 area and about 170 villages situated along the peripheries of the reserve. Among the prime measures undertaken are diversions of traffic, relocation of the villages located inside the forest. The Tiger Task Force (2005) has recommended relocation of three key villages surrounding the central area of the Sariska Tiger Reserve. However, this relocation of villages is quite contrary to the life style of the people residing within these villages. Their social and cultural attributes, needs and aspirations have not been given due consideration and the villagers are strongly resenting this move by the government. These displaced villagers have been living in perfect harmony with their environment from time immemorial and it is hard to understand how these villagers can be held responsible for degrading their natural environment, which is their lifeline. The government has failed to take into consideration the role of the neighbouring urban centres that are more responsible for the degradation of the habitat as compared to these simple villagers. In the light of these arguments, this research is an attempt to study and highlight the issues and problems related to the displacement of villages in the core area of the reserve and suggest suitable measures.

scholarly journals LOWER MIOCENE RESERVOIRS STRUCTURE AND DEPOSITIONAL ENVIRONMENTS OF THE CENTRAL PART OF DRAGON OILFIELD (VIETNAM)

2015 ◽  
pp. 40-45
Author(s):  
E. V. Frolova
Keyword(s):  
Oil Recovery ◽  
Central Area ◽  
Seismic Interpretation ◽  
Depositional Environments ◽  
Core Analysis ◽  
Geological Model ◽  
Lower Miocene ◽  
Oil Reserves ◽  
The Core ◽  
Wireline Logs

The paper presents the results of the study of the structure and depositional environments formation in the lower Miocene reservoirs in the Central area of Dragon field (Cuu Long basin, Vietnam offshore) based on litho-facial, electro-facial, seismic-facial analyses, and biostratigraphy data and the deposits thickness analysis. The geological model refining had been done through the core analysis, seismic interpretation, wireline logs integration and via defi-nition of the depositional environments. The results received permit to predict the depositional environments distribu-tion in the areas that were not identified by drilling, to make more exact the area oil reserves evaluation, to enhance the oil recovery.

scholarly journals The Nutations of Neutron Stars and Core-Crust Coupling

1987 ◽  
Vol 125 ◽  
pp. 454-454
Author(s):  
C. R. Gwinn
Keyword(s):  
Simple Model ◽  
Neutron Stars ◽  
Ideal Fluid ◽  
Density Stratification ◽  
Uniform Density ◽  
Rotating Fluid ◽  
The Core ◽  
Inertial Coupling ◽  
The Earth

Neutron stars, like the earth, are rotating fluid-filled ellipsoids. Poincaré (Bull. Astron. 27, 321, 1910), Hough (Phil. Trans. R. Soc. A186, 469, 1895) and others have discussed the nutations of such objects through a simple model, which treats the crust as rigid and the core as an ideal fluid of uniform density and vorticity. The core and crust are coupled by inertial coupling: the forces which constrain the fluid to its cavity within the crust can produce a net torque, since the cavity is ellipsoidal. Additional torques, and the effects of the elasticity in the crust and density stratification in the core, may be accomodated in such models as well (Sasao et al., Proc. IAU Symposium 78, p. 165, 1980, and references therein).

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