Flat Formation Research Articles

Nonlinear-Coupled Electric-Thermal Modeling of Underground Cable Systems

An original nonlinear-coupled electric-thermal model of underground cables with the solid sheaths is proposed. The model deals with the numerical evaluation of losses, heating, and ampacity. The computation of the current dependent losses is undertaken by means of the filament method, where conductors and sheaths are represented by a number of smaller subconductors or filaments. Furthermore, heat-transfer phenomena through an "infinite" domain beneath the soil surface are modeled combining the finite and the mapped infinite elements, respectively. The corresponding finite-element meshes are generated by the advancing front method. The numerical results presented throughout this work suggest that the International Electrotechnical Commission relation concerning the external thermal resistance for touching cables, placed in flat formation, having appreciable sheath losses, should be re-examined.

An In Situ Carcinoma of the Pancreas Forming 2 Invasive Ductal Carcinomas

A 62-year-old man underwent distal pancreatectomy for invasive pancreatic carcinoma. Histopathologically, the main lesion that obstructed the main pancreatic duct and measured 2.0 cm in diameter was a moderately differentiated adenocarcinoma with marked neural invasion. The main pancreatic duct immediately distal to the tumor was lined with carcinoma in situ, and gradual transition from carcinoma in situ to mild atypia was observed. An accessory tumor measuring 0.8 cm in diameter was located in the pancreatic tail. The adjacent pancreatic contained carcinoma in situ and flat dysplastic cells without papillary growth. We concluded that the structure of the cells lining the ducts and the comparatively flat formation and gradual transition indicated that 2 lesions, each invading the pancreatic parenchyma, arose from the intraductal tumor (carcinoma in situ or precancerous lesion).

Obstrucción de intestino delgado por metástasis de carcinoma mamario lobulillar

Although breast cancer most frequently metastasizes to the bone, lung, pleura, liver, adrenal glands and brain, it can also affect other organs such as the small bowel and ovaries, especially if the type of cancer is infiltrating and lobular. We present a case of metastases to the small bowel and ovaries from pleomorphic type infiltrating lobular breast carcinoma presenting as intestinal obstruction. Barium transit study revealed a stenosis in the jejunum and another in the terminal ileum at the ileocecal valve area. A flat formation in the area of the ileocecal valve was observed on endoscopy but the results of biopsy were negative, a fairly frequent finding due to the absence of infiltration of the intestinal mucosa. Pathological and immunohistochemical study of the intestinal and ovarian surgical specimens confirmed the diagnosis of metastases from lobular carcinoma of the breast, which was corroborated by breast biopsy.

Enhanced Mdm2 activity inhibits pRB function via ubiquitin-dependent degradation

Retinoblastoma gene product (pRB) plays critical roles in regulation of the cell cycle and tumor suppression. It is known that downregulation of pRB can stimulate carcinogenesis via abrogation of the pRB pathway, although the mechanism has not been elucidated. In this study, we found that Mdm2, a ubiquitin ligase for p53, promoted ubiquitin-dependent degradation of pRB. pRB was efficiently ubiquitinated by wild-type Mdm2 in vivo as well as in vitro, but other RB family proteins were not. Mutant Mdm2 with a substitution in the RING finger domain showed dominant-negative stabilization of pRB. Both knockout and knockdown of Mdm2 caused accumulation of pRB. Moreover, Mdm2 inhibited pRB-mediated flat formation of Saos-2 cells. Downregulation of pRB expression was correlated with a high level of expression of Mdm2 in human lung cancers. These results suggest that Mdm2 regulates function of pRB via ubiquitin-dependent degradation of pRB.

A Study on the Wheel Skidding of JR Ltd Express EMUs (1st Report,Factors Influence upon the Wheel Skidding)

To clarify the mechanism of a wheel flat formation, it is necessary to precisely identify the site, where the wheel skidding occurs. However, it is so difficult to identify the skidding occurrence sites that many studies on the wheel skidding have not refer the site where the skidding occurs. As a result, only a few development is found on the studies to specify the factors which cause the wheel skidding. The authors developed an event recorder which can record not only the behavior of the train when the skidding occurs, but also precisely identify the site where the wheel skidding occurs. The recorder was installed on a JR limited express EMU operated on a conventional line. To specify factors which cause skiddings, they analyzed the date piled up in the event recorder. At the same time, they attempted to classify, those factors systematically.

Dynamics of peat accumulation and marl flat formation in a calcareous fen, Midwestern United States

The age and sequence of peat accumulation were investigated at a calcareous fen in northeastern Illinois, USA. The purpose of this study was to identify the processes that form and sustain marl flats, which are areas of marl or tufa substrate within the fen that contain numerous rare plant species. Geomorphic, stratigraphic, and radiocarbon evidence was used to establish the processes and chronology of peat accumulation and erosion adjacent to each marl flat. The age of the base of the peat deposit varies greatly throughout the fen, ranging from 14,679 calibrated years before present (cal. years BP) to nearly modern, indicating that colonization of the sand and gravel substrate by peat occurred throughout the period from the Late Pleistocene to present. Adjacent to one marl flat, trends in basal peat age and thickness show that peat accumulation has progressed laterally inward from both sides, suggesting that the marl flat has been infilling with peat progressively by accumulation at the margins since at least 5,370 cal. years BP or longer. A second marl flat in the fen is surrounded by older, thick peat of differing ages on either edge and is bounded by fresh scarps, indicating that the marl flat currently is expanding laterally by erosion into the preexisting peat blanket. These two examples suggest a continuously repeating process, where erosion of the accumulated peat blanket forms a marl flat, which is later covered by peat accumulation. Trends in basal peat age elsewhere in the fen suggest that other marl flats may have existed in the past that have been completely infilled with peat. This study suggests that marl flat formation is a natural process that has been occurring for millennia, continuously creating habitat for the rare plant species that occupy marl flats. There is no evidence that the marl flats at this site are indicative of anthropogenic disturbance, so that management options for these areas are limited to maintaining the quality and quantity of ground-water discharge that supports both peat formation and erosion.

THE OBSERVATION METHODS USING PULSE-LASER AND THERMO-GRAPHY ON THE GEOGRAPHICAL FEATHER OF THE TIDAL FLAT

In order to observe the geographical features conveniently, as a information of the tidal flat formation, we conducted the observation using Pulse-laser and Thermo-graphy at Yuzaki-Higata tidal flat at Mizushima port, Okayama prefecture. As a result of this observation, we concluded following matters:-1) Geographical features at the area covered by the water, we could not observe the geographic featuresby Pulse-laser. However, at the other area, using Pulse-laser, we could obtain the geographical features more effectively than using the other existing methods.2) Using Thermo-graphy, we could observe the location of the tidal flat and bird's flying even in the dark.

Volcanisme triasique calco-alcalin a shoshonitique du Nevada occidental

Volcanisme triasique calco-alcalin a shoshonitique du Nevada occidental

Calculation of losses in electric power cables as the base for cable temperature analysis

Power losses refer to the heat generated in cable conducting parts (phase conductors and sheaths) and in cable insulating parts. It is necessary to know the exact data regarding heating powers for the calculation of heath transfer and cable temperatures. Heating power in phase conductors and sheaths mainly depend on current values. Exact calculation of those powers is very difficult. This paper develops a mathematical model of heating power calculation in three phase single-core cable conductors and sheaths. This model is used to determine filament currents and heating powers in phase conductors and sheaths. Geophysical features of the cable route are also considered. Three-phase single core electric power cables of 35 kV rated voltage are taken as an example. Two laying conditions (trefoil and flat formation) are considered. Sheathes are bonded and grounded at both ends. Calculation results for cables in flat configuration show that heating powers in cable sheaths do not have equal magnitude and increase with distance. The least heating power occurs in the sheath of the middle cable. Heating powers in sheaths of outer cables are of unequal magnitude too

Martensite formation and residual stresses around railway wheel flats

A finite element (FE)-based computational model is developed for the calculation of residual stresses in steel as induced by a local thermal shock. Subroutines to handle phase transformations and constitutive behaviour including volumetric expansion and transformation-induced plasticity are added to a commercial FE code. Sliding contact problems with application to railway technology are studied. Six examples of wheel flat formation are investigated in detail. In all of them rather high tensile stresses are found in the wheel rim in a domain below the top layer of phase transformations. For those combinations of train speed, wheel load and sliding duration, where the brittle martensite phase is found, surface cracks are likely. The predicted tensile stresses may propagate these cracks further into the rim material and thus cause spalling.

HREM of artificial grain boundaries in Bi- and Tri-crystals obtained by the solid-phase intergrowth process

Results of a HREM investigation of artificial grain boundaries (AGBs) in crystalline composites, obtained by solid-phase intergrowth of garnet crystals, are described. In bi-crystals with similarly oriented parts AGB is not revealed. Small misalignment results in pseudo-periodic, flat defect formation inclined relative to the intergrowth interface. If parts are in different orientations, the AGB is even and flat. Triple joints are characterized by rotation of the crystal parts and changing of the junction geometry. The AGB in a bi-crystal formed from different types of garnets is wavy. AGB deformation in this case as well as in the case of tri-crystals could be explained by the different elastic properties of its parts. [Russian Text Ignored].

The solar corona: Flat formation

During the greater part of the 11-year sunspot cycle the solar corona represents largely a similar flat formation as in the minimum (looking like a galaxy), The observed variety of coronal forms is mainly due to variations of the corona's orientation as seen from the Earth. Two limiting cases of coronal orientation are discussed: perpendicular to the plane of the sky (‘edgewise’ towards the observer) and parallel with the plane of the sky. The first case is illustrated with the coronal observations of 11 July, 1991. The second case provides an opportunity to observe the corona from above the solar magnetic poles.

Some Aspects of the Micro-Elastohydrodynamic Lubrication of Rough Cylinders Finished with a Circumferential Lay

Earlier work has shown that sinusoidal asperities with a circumferential lay give rise to transverse pressure ripples within the nominally smooth elastohydrodynamic pressure distribution. The ripples can become sufficiently large to cause elastic deformation of the generating asperities. This paper assumes that the deformed shape can be described using the Westergaard ‘dry contact’ analysis with the load (that, fraction of the total load contained within the pressure ripple) being unknown a priori. Solution of the Reynolds equation leads to the production of non-dimensional plots which give the extent of asperity deformation and the micro-elastohydrodynamic lubrication film thickness underneath the asperities as functions of the operating variables. It is shown that sensible lubricant films can exist between rough surfaces even as the nominal ratio of undeformed roughness/macro film thickness approaches 10. Different non-dimensional plots exist for different ‘sharpness’ asperities, defined as the ratio of amplitude/wavelength. For low values of the ratio, appropriate to roller bearings for example, Westergaard-type flat formation is appropriate over the total range of operating conditions considered. With sharper asperities, such as occur with W-N gears, the Westergaard flat is appropriate for relatively small deformations but, with increasing deformation, side lobes must form within the predicted ‘flat’. It is argued that this analysis will remain appropriate while the system is capable of producing high pressure in the valleys of the sinusoid but will become inappropriate as asperity deformation approaches the value it would have when bearing the total load.

Tail-Anisotropy Instability during Plasma Current Rise by Lower-Hybrid Waves in a Tokamak

The instability due to anisotropy of the electron tail temperatures during lower-hybrid current rise is investigated. Tail formation by lower-hybrid waves is studied by using a Fokker-Planck equation combined with the return field and the rf-associated terms. Quasi-linear relaxation of the electron tail distibution under the influence of the plasma waves excited by the instability is examined. It is found that the instability condition is related to the diffusion coefficient due to lower-hybrid waves, and that the decrease in the toroidal magnetic field can lead to the instability. The time scale between the instability spikes can be explained by that for the flat tail formation by lower-hybrid waves. The suppression of the instability by electron cyclotron heating is also studied. It is confirmed that the mechanism of the suppression is the enhancement of the perpendicular electron temperature.

Evolution of reefs and islands, northern Great Barrier Reef: synthesis and interpretation

This paper brings together the evidence from shallow coring, surface geomorphology, lithology of exposed rocks, superficial sediment accumulations, vegetation patterns, and the historical record derived from radiometric dating to suggest a sequence of reef and island development on the northern Great Barrier Reef in Holocene time. Reefs initially grew vertically as the sea rose rapidly from glacial low levels. This continued until vertical growth was limited by the air/sea interface as the rate of sea level rise slowed. Vertical growth was then replaced by reef flat formation at low intertidal levels, and by the lateral extension of reefs, especially to leeward. Superficial sediment accumulations on the reef flat define a series of changing habitats for further organic growth, and also record the sequence of Holocene events. Controls of the transition from vertical to horizontal reef growth will be discussed and some comments offered on latitudinal variation in reef form along the Great Barrier Reef.

New Mississippian Formations and Faunal Zones in Chesterfield Range, Portneuf Quadrangle, Southeast Idaho

Mississippian rocks in the Chesterfield Range, southeast Idaho, consist of the Lodgepole Limestone overlain by a 1,900-foot limestone-sandstone sequence here designated the Chesterfield Range Group. The lower terrigenous part, about 965 feet thick, is the Little Flat Formation; it has a basal siltstone member, a middle sandstone member, and an upper sandy limestone member. The upper carbonate part of the Chesterfield Range Group, here named the Monroe Canyon Limestone, is about 925 feet thick and contains a lower massive member, a medial medium-bedded member, and an upper cherty member. The Chesterfield Range Group is of Late Mississippian age. Three coral zones and four brachiopod zones are recognized. The coral sequence is composed of a lower Eksvasophyllum Zone succeeded by the Faberophyllum Zone and, at the top, the Caninia Zone. The lowest brachiopod zone of Quadratia hirsutiformis is succeeded by the Echinoconchus cf. E. alternatus Zone, the Striatifera brazeriana Zone, and the Spirifer brazerianus Zone. Correlations with Mississippian sequences elsewhere in the northern Rocky Mountains emphasize relationships with the Dry Lake and Old Laketown Canyon sections in northern Utah and with the Deep Creek Mountains section in southeastern Idaho. Relationships with the faunal zones recently established for the Mississippian in western Canada are indicated.

Permian Stratigraphy at Carlin Canyon, Nevada

Three new formation names are defined for a hitherto undescribed section of Permian marine sedimentary rocks exposed north of Carlin Canyon, Elko County, northeastern Nevada. The name of Buckskin Mountain formation is proposed for a 1,200-foot uniform sequence of yellow-tan quartzose calcisiltites and minor gray calcarenite beds of Wolfcampian age conformably overlying the Pennsylvanian-Permian Strathearn formation and conformably overlain by the Permian Beacon Flat formation. The name of Beacon Flat formation is proposed for a three-member unit 2,800 feet thick. The 550-foot lower member of gray, silty calcarenites and chert beds contains the Wolfcampian-Leonardian boundary. Alluvium covers the undescribed middle member. Cherty, fossiliferous, gray calcarenites make up the 1,150-foot-thick upper member, conformably overlain by the Permian Carlin Canyon formation. The name of Carlin Canyon formation is proposed for a 1,225-foot sequence of tan quartzose calcisiltites and massive brown cherts of Leonardian and possibly Guadalupian age, unconformably overlain by the Miocene-Pliocene Humboldt formation. The Buckskin Mountain formation is probably correlative with parts of the Carbon Ridge and Arcturus formations. Carlin Canyon formation sediments reflect orogeny and volcanism taking place in western Nevada, as well as local uplift, during Leonardian and possibly Guadalupian time.

South Flat Formation, New Upper Cretaceous Formation of Central Utah

The South Flat formation is a new medical (?) Montanan unit recognized in the Laramide orogenic belt of central Utah. It consists of 2,850 feet of flood plain and piedmont deposits that are exposed in the northern part of the Gunnison Plateau. The new formation is tentatively correlated with the Blackhawk formation in the Wasatch Plateau on the east. Although the distribution of the South Flat formation appears to be restricted, it is important from a tectonic standpoint. Angular unconformities that separate it from the underlying Indianola group and the overlying Price River formation demonstrate that the early Laramide orogenic movement consisted of two distinct impulses in central Utah.