ROLLER RIG TESTING AT THE CZECH TECHNICAL UNIVERSITY

Directory of Open Access Journals (Sweden)

J. Kalivoda

2016-08-01

Full Text Available Purpose. Although the advancements in computer simulation technology have paved way to provide very reliable simulation results, track tests still play an essential role during the process of development and homologation of any railway vehicle. On the other hand, track tests depend on weather conditions, are difficult to organize and are not suitable for testing vehicles in critical situations. On a roller rig, the tested vehicle is longitudinally fixed and a track is replaced by rotating rollers. Such device offer testing of railway vehicle running dynamics in safe and stable laboratory environment. The purpose of an article is to investigate and describe roller rig testing at the Czech technical university in Prague (CTU. Methodology. In the paper it is shown the history of development of the scaled CTU roller rig from the earlier stages until the current projects for which the CTU roller rig is utilized for. The current design of the experimental bogie, roller rig, sensors instrumentation and types of experiments conducted at the CTU roller rig are described in more detail. Findings. Although the differences in vehicle behaviour on a track and a scaled model on a roller rig are not negligible, scaled roller rig experiments are found as a relatively inexpensive way for verification and demonstration of computer simulations results. They are especially useful for verification of multibody system simulations (MBS of entirely new running gear concepts. Originality. The CTU roller rig is currently used for the experiments with active controlled wheelset guidance. According to simulations results published in many papers such systems offer, in principle, better performance compared to conventional passive vehicles. However, utilization and testing of active controlled wheelset guidance on vehicles is still rare. CTU roller rig serves as a tool to verify computer simulations and demonstrate benefits of active wheelset guidance. Practical value

75 FR 53980 - Notice of Field Tours for the Pinedale Anticline Working Group

Science.gov (United States)

2010-09-02

... Project Area (PAPA) 2008 Supplemental Environmental Impact Statement (SEIS), and the Pinedale Anticline...) PAWG will conduct field tours of the Pinedale Anticline Project Area (PAPA). Tours are open to the... . SUPPLEMENTARY INFORMATION: The PAWG was established by the EIS ROD for the PAPA on July 27, 2000, and carried...

Ice-skating and roller disco injuries in Dublin.

OpenAIRE

Horner, C.; McCabe, M. J.

1984-01-01

A comparative study was carried out on a series of 72 ice-skating and 57 roller skating injuries over a sixteen month period. The average patient age was 20.5 years in the ice-skating group and 16.5 years in the roller skating group. Females predominated in both groups accounting for 72% of ice-skaters injured and 77% of roller skaters injured. Ice-skaters sustained more serious injuries than roller skaters as was evident from the significant difference in fracture numbers in the two groups. ...

Dome craters on Ganymede

International Nuclear Information System (INIS)

Moore, J.M.; Malin, M.C.

1987-01-01

Voyager observations reveal impact craters on Ganymede that are characterized by the presence of broad, high albedo, topographic domes situated within a central pit. Fifty-seven craters with central domes were identified in images covering approx. 50% of the surface. Owing to limitations in resolution, and viewing and illumination angles, the features identified are most likely a subset of dome craters. The sample appears to be sufficiently large to infer statistically meaningful trends. Dome craters appear to fall into two distinct populations on plots of the ratio of dome diameter to crater rim diameter, large-dome craters and small-dome craters. The two classes are morphologically distinct from one another. In general, large dome craters show little relief and their constituent landforms appear subdued with respect to fresh craters. The physical attributes of small-dome craters are more sharply defined, a characteristic they share with young impact craters of comparable size observed elsewhere in the solar system. Both types of dome craters exhibit central pits in which the dome is located. As it is difficult to produce domes by impact and/or erosional processes, an endogenic origin for the domes is reasonably inferred. Several hypotheses for their origin are proposed. These hypotheses are briefly reviewed

Ice-skating and roller disco injuries in Dublin.

Science.gov (United States)

Horner, C.; McCabe, M. J.

1984-01-01

A comparative study was carried out on a series of 72 ice-skating and 57 roller skating injuries over a sixteen month period. The average patient age was 20.5 years in the ice-skating group and 16.5 years in the roller skating group. Females predominated in both groups accounting for 72% of ice-skaters injured and 77% of roller skaters injured. Ice-skaters sustained more serious injuries than roller skaters as was evident from the significant difference in fracture numbers in the two groups. Ice-skating fractures accounted for 40% of all injuries while roller skating fractures were only 14% of their total injuries. The majority of ice-skating fractures occurred in females. As a result of our study we recommended several preventative measures. Images p207-a p207-b PMID:6487948

21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through the...

49 CFR 215.117 - Defective roller bearing adapter.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Defective roller bearing adapter. 215.117 Section... Suspension System § 215.117 Defective roller bearing adapter. A railroad may not place or continue in service a car, if the car has a roller bearing adapter that is— (a) Cracked or broken; (b) Not in its design...

Subsurface geology of a potential waste emplacement site, Salt Valley Anticline, Grand County, Utah

International Nuclear Information System (INIS)

Hite, R.J.

1977-01-01

The Salt Valley anticline, which is located about 32 km northeast of Moab, Utah, is perhaps one of the most favorable waste emplacement sites in the Paradox basin. The site, which includes about 7.8 km 2 , is highly accessible and is adjacent to a railroad. The anticline is one of a series of northwest-trending salt antilcines lying along the northeast edge of the Paradox basin. These anticlines are cored by evaporites of the Paradox Member of the Hermosa Formation of Middle Pennsylvanian age. The central core of the Salt Valley anticline forms a ridgelike mass of evaporites that has an estimated amplitude of 3,600 m. The evaporite core consists of about 87 percent halite rock, which includes some potash deposits; the remainder is black shale, silty dolomite, and anhydrite. The latter three lithologies are referred to as ''marker beds.'' Using geophysical logs from drill holes on the anticline, it is possible to demonstrate that the marker beds are complexly folded and faulted. Available data concerning the geothermal gradient and heatflow at the site indicate that heat from emplaced wastes should be rapidly dissipated. Potentially exploitable resources of potash and petroleum are present at Salt Valley. Development of these resources may conflict with use of the site for waste emplacement

Engine testing of ceramic cam-roller followers

Energy Technology Data Exchange (ETDEWEB)

Kalish, Y. (Detroit Diesel Corp., MI (United States))

1992-04-01

For several years, DDC has been developing monolithic ceramic heat engine components. One of the components, developed for an application in our state-of-the-art on-highway, heavy-duty diesel engine, the Series 60, is a silicon nitride cam-roller follower. Prior to starting this program, each valve train component in the Series 60 was considered for conversion to a ceramic material. Many advantages and disadvantages (benefits and risks) were considered. From this effort, one component was selected, the cam-roller follower. Using a system design approach, a ceramic cam-roller follower offered functional improvement at a reasonable cost. The purpose of the project was to inspect and test 100 domestically produced silicon nitride cam-roller followers built to the requirements of the DDC series 60 engine.

Design algorithm for generatrix profile of cylindrical crowned rollers

Directory of Open Access Journals (Sweden)

Creţu Spiridon

2017-01-01

Full Text Available The cross-section of roller profile controls the pressure distribution in the contact area and radically affects the roller bearings basic dynamic load rating and rating lives. Today the most used roller profiles are the logarithmic profile and cylindrical-crowned (ZB profile. The logarithmic profile has a continuous evolution with no discontinuities till the intersection with the end fillet while ZB profile has two more discontinuities at the intersections points between the crowning circle and straight line generatrix. Using a semianalytical method, a numerical study has been carried out to find the optimum ZB profile for rollers incorporated in cylindrical rollers bearings. The basic reference rating life (L10_r has been used as optimization criterion.

49 CFR 230.103 - Tender roller bearing journal boxes.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Tender roller bearing journal boxes. 230.103... Locomotives and Tenders Running Gear § 230.103 Tender roller bearing journal boxes. Tender roller bearing journal boxes shall be maintained in a safe and suitable condition. ...

Numerically Analysed Thermal Condition of Hearth Rollers with the Water-Cooled Shaft

Directory of Open Access Journals (Sweden)

A. V. Ivanov

2016-01-01

Full Text Available Continuous furnaces with roller hearth have wide application in the steel industry. Typically, furnaces with roller hearth belong to the class of medium-temperature heat treatment furnaces, but can be used to heat the billets for rolling. In this case, the furnaces belong to the class of high temperature heating furnaces, and their efficiency depends significantly on the reliability of the roller hearth furnace. In the high temperature heating furnaces are used three types of watercooled shaft rollers, namely rollers without insulation, rollers with insulating screens placed between the barrel and the shaft, and rollers with bulk insulation. The definition of the operating conditions of rollers with water-cooled shaft greatly facilitates the choice of their design parameters when designing. In this regard, at the design stage of the furnace with roller hearth, it is important to have information about the temperature distribution in the body of the rollers at various operating conditions. The article presents the research results of the temperature field of the hearth rollers of metallurgical heating furnaces. Modeling of stationary heat exchange between the oven atmosphere and a surface of rollers, and between the cooling water and shaft was executed by finite elements method. Temperature fields in the water-cooled shaft rollers of various designs are explored. The water-cooled shaft rollers without isolation, rollers with screen and rollers with bulk insulation, placed between the barrel and the water-cooled shaft were investigated. Determined the change of the thermo-physic parameters of the coolant, the temperature change of water when flowing in a pipe and shaft, as well as the desired pressure to supply water with a specified flow rate. Heat transfer coefficients between the cooling water and the shaft were determined directly during the solution based on the specified boundary conditions. Found that the greatest heat losses occur in the

Reassessing the roles of PIN proteins and anticlinal microtubules during pavement cell morphogenesis

Energy Technology Data Exchange (ETDEWEB)

Belteton, Samuel; Sawchuk, Megan G.; Donohoe, Bryon S.; Scarpella, Enrico; Szymanski, Daniel B.

2017-11-30

The leaf epidermis is a biomechanical shell that influences the size and shape of the organ. Its morphogenesis is a multiscale process in which nanometer-scale cytoskeletal protein complexes, individual cells, and groups of cells pattern growth and define macroscopic leaf traits. Interdigitated growth of neighboring cells is an evolutionarily conserved developmental strategy. Understanding how signaling pathways and cytoskeletal proteins pattern cell walls during this form of tissue morphogenesis is an important research challenge. The cellular and molecular control of a lobed cell morphology is currently thought to involve PIN-FORMED (PIN)-type plasma membrane efflux carriers that generate subcellular auxin gradients. Auxin gradients were proposed to function across cell boundaries to encode stable offset patterns of cortical microtubules and actin filaments between adjacent cells. Many models suggest that long-lived microtubules along the anticlinal cell wall generate local cell wall heterogeneities that restrict local growth and specify the timing and location of lobe formation. Here we used Arabidopsis reverse genetics and multivariate long-term time-lapse imaging to test current cell shape control models. We found that neither PIN proteins nor microtubules along the anticlinal wall predict the patterns of lobe formation. In fields of lobing cells, anticlinal microtubules are not correlated with cell shape and are unstable at the time scales of cell expansion. Our analyses indicate that anticlinal microtubules have multiple functions in pavement cells, and that lobe initiation is likely controlled by complex interactions among cell geometry, cell wall stress patterns, and transient microtubule networks that span the anticlinal and periclinal walls.

Photolineations, folding and breaking tectonics in the Vest main anticline in the northern Ruhr Carboniferous

Energy Technology Data Exchange (ETDEWEB)

Adler, R E

1978-10-01

Discusses the use of photolineaments and other structural features obtained from ERTS-1 and LANDSAT satellites for determining the transition zone between the 'Vest' main anticline and the Liffe Syncline, the core area of the Auguste-Victoria anticline, and the Ludinghausen syncline.

Intra-Continental Deformation by Mid-Crustal Shearing and Doming in a Cenozoic Compressive Setting Along the Ailao Shan-Red River Shear Zone

Science.gov (United States)

Zhang, B.

2016-12-01

-continental deformation. They record pre-strike-slip shearing events, i.e., regional horizontal shearing flow in the mid-crust and the exhumation and uplift via anticlinal doming, in the intra-continental shortening setting in the Eastern Himalayan Syntaxis region.

Kinematics and Dynamics of Roller Chain Drives

DEFF Research Database (Denmark)

Fuglede, Niels

There are two main subjects of this work: Kinematic and dynamic modeling and analysis of roller chain drives. In the kinematic analysis we contribute first with a complete treatment of the roller chain drive modeled as a four-bar mechanism. This includes a general, exact and approximate analysis...... which is useful for predicting the characteristic loading of the roller chain drive. As a completely novel contribution, a kinematic model and analysis is presented which includes both spans and sprockets in a simple chain drive system. A general procedure for determination of the total wrapping length...... is presented, which also allows for exact sprocket center positions for a chain with a given number of links. Results show that the total chain wrapping length varies periodically with the tooth frequency. These results are of practical importance to both the design, installation and operation of roller chain...

Reassessing the Roles of PIN Proteins and Anticlinal Microtubules during Pavement Cell Morphogenesis.

Science.gov (United States)

Belteton, Samuel A; Sawchuk, Megan G; Donohoe, Bryon S; Scarpella, Enrico; Szymanski, Daniel B

2018-01-01

The leaf epidermis is a biomechanical shell that influences the size and shape of the organ. Its morphogenesis is a multiscale process in which nanometer-scale cytoskeletal protein complexes, individual cells, and groups of cells pattern growth and define macroscopic leaf traits. Interdigitated growth of neighboring cells is an evolutionarily conserved developmental strategy. Understanding how signaling pathways and cytoskeletal proteins pattern cell walls during this form of tissue morphogenesis is an important research challenge. The cellular and molecular control of a lobed cell morphology is currently thought to involve PIN-FORMED (PIN)-type plasma membrane efflux carriers that generate subcellular auxin gradients. Auxin gradients were proposed to function across cell boundaries to encode stable offset patterns of cortical microtubules and actin filaments between adjacent cells. Many models suggest that long-lived microtubules along the anticlinal cell wall generate local cell wall heterogeneities that restrict local growth and specify the timing and location of lobe formation. Here, we used Arabidopsis ( Arabidopsis thaliana ) reverse genetics and multivariate long-term time-lapse imaging to test current cell shape control models. We found that neither PIN proteins nor long-lived microtubules along the anticlinal wall predict the patterns of lobe formation. In fields of lobing cells, anticlinal microtubules are not correlated with cell shape and are unstable at the time scales of cell expansion. Our analyses indicate that anticlinal microtubules have multiple functions in pavement cells and that lobe initiation is likely controlled by complex interactions among cell geometry, cell wall stress patterns, and transient microtubule networks that span the anticlinal and periclinal walls. © 2018 American Society of Plant Biologists. All Rights Reserved.

Citronelle Dome: A giant opportunity for multizone carbon storage and enhanced oil recovery in the Mississippi Interior Salt Basin of Alabama

Science.gov (United States)

Esposito, R.A.; Pashin, J.C.; Walsh, P.M.

2008-01-01

The Citronelle Dome is a giant, salt-cored anticline in the eastern Mississippi Interior Salt Basin of southern Alabama that is located near several large-scale, stationary, carbon-emitting sources in the greater Mobile area. The dome forms an elliptical, four-way structural closure containing opportunities for CO2-enhanced oil recovery (CO2-EOR) and large-capacity saline reservoir CO2 sequestration. The Citronelle oil field, located on the crest of the dome, has produced more than 169 million bbl of 42-46?? API gravity oil from sandstone bodies in the Lower Cretaceous Rodessa Formation. The top seal for the oil accumulation is a thick succession of shale and anhydrite, and the reservoir is underfilled such that oil-water contacts are typically elevated 30-60 m (100-200 ft) above the structural spill point. Approximately 31-34% of the original oil in place has been recovered by primary and secondary methods, and CO2-EOR has the potential to increase reserves by up to 20%. Structural contour maps of the dome demonstrate that the area of structural closure increases upward in section. Sandstone units providing prospective carbon sinks include the Massive and Pilot sands of the lower Tuscaloosa Group, as well as several sandstone units in the upper Tuscaloosa Group and the Eutaw Formation. Many of these sandstone units are characterized by high porosity and permeability with low heterogeneity. The Tuscaloosa-Eutaw interval is capped by up to 610 m (2000 ft) of chalk and marine shale that are proven reservoir seals in nearby oil fields. Therefore, the Citronelle Dome can be considered a major geologic sink where CO2 can be safely stored while realizing the economic benefits associated with CO2-EOR. Copyright ?? 2008. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

A detection method of subrecent to recent tectonic activity in the anticlinal system of the northern Negev, Israel

International Nuclear Information System (INIS)

Zilberman, E.; Wachs, D.

1988-01-01

Geomorphological and geophysical methods combined with borehole information were employed to search for possible subrecent small-scale vertical movement along the anticlinal fold belt of the central Negev, Israel. Such tectonic deformation might indicate displacement on the buried reverse faults underneath the anticlines. Variations in the thickness of the alluvial fill in the study area, which are in accordance with the fold structures, could be an indication of recent folding activity along the anticlinal system. In order to detect these thickness variations in the alluvial fill, seismic refraction and electrical resistivity measurements were carries out along the valley of Nahal Besor, which crosses the anticlinal belt. The thickness variations of the alluvial fill along the valley were not found to indicate any significant tectonic movement along the anticlines during the Pleistocene. The thickest alluvium was found overlying a karst bedrock, hence karst relief is suggested to be responsible for these variations

Roller-chain Drives Mechanics using Multibody Dynamics Tools

DEFF Research Database (Denmark)

Ambrosio, Jorge A. C.; Hansen, John Michael

1999-01-01

An integrated model for the simulation of roller-chain drives based on a multibody dynamics methodology is presented here in order to describeits complex dynamic behavior. The chain is modeled by masses lumped at the roller locations and connected by translational spring-damper elements in order ...... engagement on the sprockets responsible for the polygonal effect is thoroughly analyzed and the induced impulsive forces developed during that action are treated by a strategy where kinematic constraints between sprockets and rollers are added and deleted....

A FILTRATION METHOD AND APPARATUS INCLUDING A ROLLER WITH PORES

DEFF Research Database (Denmark)

2008-01-01

The present invention offers a method for separating dry matter from a medium. A separation chamber is at least partly defined by a plurality of rollers (2,7) and is capable of being pressure regulated. At least one of the rollers is a pore roller (7) having a surface with pores allowing permeabi...

Crestal graben fluid evolution during growth of the Puig-reig anticline (South Pyrenean fold and thrust belt)

Science.gov (United States)

Cruset, David; Cantarero, Irene; Travé, Anna; Vergés, Jaume; John, Cedric M.

2016-11-01

The Puig-reig anticline, located in the South Pyrenean fold and thrust belt, developed during the Alpine compression, which affected the upper Eocene-lower Oligocene sediments of the Solsona and Berga Formations. In this study, we highlight the controls on formation of joints and reverse, strike-slip and normal faults developed in the crest domain of the Puig-reig anticline as well as the relationships between fluids and these fractures. We integrated structural, petrographic and geochemical studies, using for the first time in the SE Pyrenees the clumped isotopes thermometry to obtain reliable temperatures of calcite precipitation. Structural and microstructural analysis demonstrate that at outcrop scale fracturing was controlled by rigidity contrasts between layers, diagenesis and structural position within the anticline, whereas grain size, cementation and porosity controlled deformation at the microscopic scale. Petrographic and geochemical studies of calcite precipitated in host rock porosity and fault planes reveal the presence of two migrating fluids, which represents two different stages of evolution of the Puig-reig anticline. During the layer-parallel shortening, hydrothermal fluids with temperatures between 92 and 130 °C circulated through the main thrusts to the permeable host rocks, reverse and most of strike-slip faults precipitating as cement Cc1. During the fold growth, meteoric waters circulated downwards through normal and some strike-slip faults and mixed at depth with the previous hydrothermal fluid, precipitating as cement Cc2 at temperatures between 77 and 93 °C. Integration of the results from the Puig-reig anticline in this work and the El Guix anticline indicates that hydrothermal fluids did not reach the El Guix anticline, in which only meteoric and evolved meteoric waters circulated along the fold.

Solar radiation on domed roofs

Energy Technology Data Exchange (ETDEWEB)

Faghih, Ahmadreza K.; Bahadori, Mehdi N. [School of Mechanical Engineering, Sharif University of Technology, Tehran (Iran)

2009-11-15

Solar radiation received and absorbed by four domed roofs was estimated and compared with that of a flat roof. The domed roofs all had the same base areas, and equal to that of the flat roof. One of the roofs considered was the dome of the St. Peter's Church in Rome. Compared with the other roofs considered, this dome had a higher aspect ratio. It was found that all domed roofs received more solar radiation than the flat roof. Considering glazed tiles to cover a selected dome in Iran and the dome of the St. Peter's Church, it was found that the solar radiation absorbed by these roofs is reduced appreciably. In the case of the dome of St. Peter's Church, the amount of radiation absorbed was roughly equal to that absorbed by the comparable flat roof in the warm months. In the case of the glazed reference dome located in Yazd, Iran (a city with very high solar radiation), the radiation absorbed was less than that of flat roof at all times. In addition to aesthetics, this may be a reason for employing glazed tiles to cover the domes of all mosques, shrines, and other large buildings in Iran. (author)

Roller compaction of moist pharmaceutical powders.

Science.gov (United States)

Wu, C-Y; Hung, W-L; Miguélez-Morán, A M; Gururajan, B; Seville, J P K

2010-05-31

The compression behaviour of powders during roller compaction is dominated by a number of factors, such as process conditions (roll speed, roll gap, feeding mechanisms and feeding speed) and powder properties (particle size, shape, moisture content). The moisture content affects the powder properties, such as the flowability and cohesion, but it is not clear how the moisture content will influence the powder compression behaviour during roller compaction. In this study, the effect of moisture contents on roller compaction behaviour of microcrystalline cellulose (MCC, Avicel PH102) was investigated experimentally. MCC samples of different moisture contents were prepared by mixing as-received MCC powder with different amount of water that was sprayed onto the powder bed being agitated in a rotary mixer. The flowability of these samples were evaluated in terms of the poured angle of repose and flow functions. The moist powders were then compacted using the instrumented roller compactor developed at the University of Birmingham. The flow and compression behaviour during roller compaction and the properties of produced ribbons were examined. It has been found that, as the moisture content increases, the flowability of moist MCC powders decreases and the powder becomes more cohesive. As a consequence of non-uniform flow of powder into the compaction zone induced by the friction between powder and side cheek plates, all produced ribbons have a higher density in the middle and lower densities at the edges. For the ribbons made of powders with high moisture contents, different hydration states across the ribbon width were also identified from SEM images. Moreover, it was interesting to find that these ribbons were split into two halves. This is attributed to the reduction in the mechanical strength of moist powder compacts with high moisture contents produced at high compression pressures. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Salmonella transfer during pilot plant scale washing and roller conveying of tomatoes.

Science.gov (United States)

Wang, Haiqiang; Ryser, Elliot T

2014-03-01

Salmonella transfer during washing and roller conveying of inoculated tomatoes was quantified using a pilot scale tomato packing line equipped with plastic, foam, or brush rollers. Red round tomatoes (2.3 kg) were dip inoculated with Salmonella enterica serovar Typhimurium LT2 (avirulent) (4 log CFU/g), air dried for 2 h, and then washed in sanitizer-free water for 2 min. Inoculated tomatoes were then passed single file over a 1.5-m conveyor equipped with plastic, foam, or brush rollers followed by 25 previously washed uninoculated tomatoes. Tomato samples were collected after 2 min of both washing and roller conveying, with all 25 uninoculated tomatoes collected individually after conveying. Roller surface samples were collected before and after conveying the uninoculated tomatoes. Both tomato and surface samples were quantitatively examined for Salmonella by direct plating or membrane filtration using xylose lysine Tergitol 4 agar. Regardless of the roller type, Salmonella populations on inoculated tomatoes did not significantly (P conveyors. After conveying uninoculated tomatoes over contaminated foam rollers, 96% of the 25 tomatoes were cross-contaminated with Salmonella at >100 CFU per tomato. With plastic rollers, 24 and 76% of tomatoes were cross-contaminated with Salmonella at 10 to 100 and 1 to 10 CFU per tomato, respectively. In contrast, only 8% of 25 tomatoes were cross-contaminated with brush rollers with Salmonella populations of 1 to 10 CFU per tomato. Overall, cross-contamination was greatest with foam, followed by plastic and brush rollers (P < 0.05). Adding peroxyacetic acid or chlorine to the wash water significantly decreased cross-contamination during tomato conveying, with chlorine less effective in controlling Salmonella on foam compared with plastic and brush rollers.

Near-dome geologic findings - Richton Dome, Mississippi: annual status report for FY 83

International Nuclear Information System (INIS)

1984-10-01

Basin Analysis is a study of the regional and local stratigraphic, tectonic, and salt-tectonic conditions that influenced the development of the Mississippi Salt Basin and Richton Dome, an element within that basin. During FY 83, work was concentrated on the local area surrounding Richton Dome and included the writing of the Midyear FY 83 Richton Dome Screening and Suitability Review, input to the Site Characterization Plan that is being prepared by the Southern Region Geologic Project Manager, and initial development of a near-dome geologic model. The geologic model was compiled using information from approximately 300 oil and gas well geophysical logs and 128 line km (80 line mi) of seismic-reflection profiles. In addition to analysis and interpretation of the logs and profiles, stratigraphic data from each were assembled in a computer-based file and were used to produce computer-generated structural contour maps. Major findings from the analyses include a new configuration for the northern end of Richton Dome and improved definitions of near-dome faults and the rim syncline on the northern and eastern flanks of Richton Dome. 4 references, 6 figures

Errors of car wheels rotation rate measurement using roller follower on test benches

Science.gov (United States)

Potapov, A. S.; Svirbutovich, O. A.; Krivtsov, S. N.

2018-03-01

The article deals with rotation rate measurement errors, which depend on the motor vehicle rate, on the roller, test benches. Monitoring of the vehicle performance under operating conditions is performed on roller test benches. Roller test benches are not flawless. They have some drawbacks affecting the accuracy of vehicle performance monitoring. Increase in basic velocity of the vehicle requires increase in accuracy of wheel rotation rate monitoring. It determines the degree of accuracy of mode identification for a wheel of the tested vehicle. To ensure measurement accuracy for rotation velocity of rollers is not an issue. The problem arises when measuring rotation velocity of a car wheel. The higher the rotation velocity of the wheel is, the lower the accuracy of measurement is. At present, wheel rotation frequency monitoring on roller test benches is carried out by following-up systems. Their sensors are rollers following wheel rotation. The rollers of the system are not kinematically linked to supporting rollers of the test bench. The roller follower is forced against the wheels of the tested vehicle by means of a spring-lever mechanism. Experience of the test bench equipment operation has shown that measurement accuracy is satisfactory at small rates of vehicles diagnosed on roller test benches. With a rising diagnostics rate, rotation velocity measurement errors occur in both braking and pulling modes because a roller spins about a tire tread. The paper shows oscillograms of changes in wheel rotation velocity and rotation velocity measurement system’s signals when testing a vehicle on roller test benches at specified rates.

Reassessing the Roles of PIN Proteins and Anticlinal Microtubules during Pavement Cell Morphogenesis1[OPEN

Science.gov (United States)

Sawchuk, Megan G.; Scarpella, Enrico

2018-01-01

The leaf epidermis is a biomechanical shell that influences the size and shape of the organ. Its morphogenesis is a multiscale process in which nanometer-scale cytoskeletal protein complexes, individual cells, and groups of cells pattern growth and define macroscopic leaf traits. Interdigitated growth of neighboring cells is an evolutionarily conserved developmental strategy. Understanding how signaling pathways and cytoskeletal proteins pattern cell walls during this form of tissue morphogenesis is an important research challenge. The cellular and molecular control of a lobed cell morphology is currently thought to involve PIN-FORMED (PIN)-type plasma membrane efflux carriers that generate subcellular auxin gradients. Auxin gradients were proposed to function across cell boundaries to encode stable offset patterns of cortical microtubules and actin filaments between adjacent cells. Many models suggest that long-lived microtubules along the anticlinal cell wall generate local cell wall heterogeneities that restrict local growth and specify the timing and location of lobe formation. Here, we used Arabidopsis (Arabidopsis thaliana) reverse genetics and multivariate long-term time-lapse imaging to test current cell shape control models. We found that neither PIN proteins nor long-lived microtubules along the anticlinal wall predict the patterns of lobe formation. In fields of lobing cells, anticlinal microtubules are not correlated with cell shape and are unstable at the time scales of cell expansion. Our analyses indicate that anticlinal microtubules have multiple functions in pavement cells and that lobe initiation is likely controlled by complex interactions among cell geometry, cell wall stress patterns, and transient microtubule networks that span the anticlinal and periclinal walls. PMID:29192026

Engine testing of ceramic cam-roller followers. Final report

Energy Technology Data Exchange (ETDEWEB)

Kalish, Y. [Detroit Diesel Corp., MI (United States)

1992-04-01

For several years, DDC has been developing monolithic ceramic heat engine components. One of the components, developed for an application in our state-of-the-art on-highway, heavy-duty diesel engine, the Series 60, is a silicon nitride cam-roller follower. Prior to starting this program, each valve train component in the Series 60 was considered for conversion to a ceramic material. Many advantages and disadvantages (benefits and risks) were considered. From this effort, one component was selected, the cam-roller follower. Using a system design approach, a ceramic cam-roller follower offered functional improvement at a reasonable cost. The purpose of the project was to inspect and test 100 domestically produced silicon nitride cam-roller followers built to the requirements of the DDC series 60 engine.

EVALUATION OF A LOW FRICTION - HIGH EFFICIENCY ROLLER BEARING ENGINE

Energy Technology Data Exchange (ETDEWEB)

Kolarik, Robert V. II; Shattuck, Charles W.; Copper, Anthony P.

2009-06-30

This Low Friction (High Efficiency Roller Bearing) Engine (LFE) report presents the work done by The Timken Company to conduct a technology demonstration of the benefits of replacing hydrodynamic bearings with roller bearings in the crankshaft and camshaft assemblies of an internal combustion engine for the purpose of collecting data sufficient to prove merit. The engines in the present study have been more extensively converted to roller bearings than any previous studies (40 needle roller bearings per engine) to gain understanding of the full potential of application of bearing technology. The project plan called for comparative testing of a production vehicle which was already respected for having demonstrated low engine friction levels with a rollerized version of that engine. Testing was to include industry standard tests for friction, emissions and fuel efficiency conducted on instrumented dynamometers. Additional tests for fuel efficiency, cold start resistance and other measures of performance were to be made in the actual vehicle. Comparative measurements of noise, vibration and harshness (NVH), were planned, although any work to mitigate the suspected higher NVH level in the rollerized engine was beyond the scope of this project. Timken selected the Toyota Avalon with a 3.5L V-6 engine as the test vehicle. In an attempt to minimize cost and fabrication time, a ‘made-from’ approach was proposed in which as many parts as possible would be used or modified from production parts to create the rollerized engine. Timken commissioned its test partner, FEV Engine Technology, to do a feasibility study in which they confirmed that using such an approach was possible to meet the required dimensional restrictions and tolerances. In designing the roller bearing systems for the crank and cam trains, Timken utilized as many production engine parts as possible. The crankshafts were produced from production line forgings, which use Timken steel, modified with special

Direct fabrication of rigid microstructures on a metallic roller using a dry film resist

International Nuclear Information System (INIS)

Jiang, Liang-Ting; Huang, Tzu-Chien; Chang, Chih-Yuan; Ciou, Jian-Ren; Yang, Sen-Yeu; Huang, Po-Hsun

2008-01-01

This paper presents a novel method to fabricate a metallic roller mold with microstructures on its surface using a dry film resist (DFR). The DFR is laminated uniformly onto the curvy surface of a copper roller. After that, the micro-scale photoresist on the surface of the roller can be patterned by non-planar lithography using a flexible film photomask, followed by ferric chloride wet etching to obtain the desired microstructures. This method overcomes the uniformity issue of photoresist coating on rollers, and solves the molds sliding problem during the embossing process because the microstructures are fabricated directly on the roller surface. Furthermore, the rigid metallic roller mold has excellent strength durability and temperature endurance, which can be used in roller hot embossing with a high embossing pressure. The fabricated microstructure roller mold is used as a mold in the hybrid extrusion roller embossing process and successfully fabricates uniform micro-scale prominent line arrays on PC films. This result proves that the roller fabricated by this method can be successfully used in roller embossing for microstructure mass production. The excellent flatness of dry film resist laminating is the key in this fabrication process. The flexible film photomask can be easily designed using CAD software; this roller fabrication method enhances the design flexibility and reduces the cost and time

Roller Locking Brake

Science.gov (United States)

Vranish, John M.

1993-01-01

Roller locking brake is normally braking rotary mechanism allowing free rotation when electromagnet in mechanism energized. Well suited to robots and other machinery which automatic braking upon removal of electrical power required. More compact and reliable. Requires little electrical power to maintain free rotation and exhibits minimal buildup of heat.

KINEMATICS AND DYNAMICS MODELS OF CYLINDRICAL ROLLER BEARING OF RAILWAY TRANSPORT

Directory of Open Access Journals (Sweden)

A. V. Gaydamaka

2014-05-01

Full Text Available Purpose. Lack of kinematics models and imperfection of the known dynamics models of the roller bearings of railway rolling stock axle-boxes do not allow designing the optimal structure of bearing cages, providing the required service life and reliability of bearing units of wheel sets for cars and locomotives. The studies of kinematics and dynamics of roller bearings of axle boxes for cars and locomotives and modeling of their parts interaction to create the analytical method of bearing cages calculation are necessary. Methodology. This purpose has been achieved due to the modeling of kinematics of the ideal (without gaps and real (taking account the gaps, manufacturing and installation errors bearings, substantiation of the transfer mechanism of motion from the rollers to bearing cage, modeling the dynamics of rolling, research of interaction forces of the rollers with bearing cage. Findings. It is established that the kinematics of ideal bearing is determined by the contact deformations of the rollers and rings, when the kinematics of real bearing depends mainly on the side gaps in the windows of the bearing cage. On the basis of studies of the real bearing kinematics the dynamics models of the rollers and bearing cage interaction were constructed. The conducted studies of kinematics and dynamics of rolling bearings have changed our view of them as of the planetary mechanism, explained the reason of bearing cage loading, and confirmed the possibility of destruction during operation. Originality. It was first proposed a mechanism for motion transfer from the rollers to the bearing cage of roller bearings, consisting in that the side gap in the bearing cage window is reduced gradually multiple of the number of rollers of radial loading area according to the bearing cage motion. The models of roller bearing dynamics, which allow calculating the interaction forces of parts for all modes of operation, were improved. Practical value. Use of the

Tiechanshan-Tunghsiao anticline earthquake analysis: Implications for northwestern Taiwan potential carbon dioxide storage site seismic hazard

Directory of Open Access Journals (Sweden)

Ruey-Juin Rau

2017-01-01

Full Text Available We analyze the seismicity and earthquake focal mechanisms beneath the Tiechanshan-Tunghsiao (TCS-TH anticline over the last two decades for seismic hazard evaluation of a potential carbon dioxide storage site in northwestern Taiwan. Seismicity in the TCS-TH anticline indicates both spatial and temporal clustering at a depth range of 7 - 12 km. Thirteen 3.0 ≤ ML ≤ 5.2 earthquake focal mechanisms show a combination of thrust, strike-slip, and normal faulting mechanisms under the TCS-TH anticline. A 1992 ML 5.2 earthquake with a focal depth of ~10 km, the largest event ever recorded beneath the TCS-TH anticline during the last two decades, has a normal fault mechanism with the T-axis trending NNE-SSW and nodal planes oriented NNW-SSE, dipping either gently to the NNE or steeply to the SSW. Thrust fault mechanisms that occurred with mostly E-W or NWW-SEE striking P-axes and strike-slip faulting events indicate NWW-SEE striking P-axes and NNE-SSW trending T-axes, which are consistent with the regional plate convergence direction. For the strike-slip faulting events, if we take the N-S or NNW-SSE striking nodal planes as the fault planes, the strike-slip faults are sinistral motions and correspond to the Tapingting fault, which is a strike-slip fault reactivated from the inherited normal fault and intersects the Tiechanshan and Tunghsiao anticlines.

A study on rheological characteristics of roller milled fenugreek fractions.

Science.gov (United States)

Sakhare, Suresh D; Inamdar, Aashitosh A; Prabhasankar, P

2016-01-01

Fenugreek seeds were fractionated by roller milling to get various fractions. The roller milled fractions and whole fenugreek flour (WFF) were evaluated for the flow behavior and time-dependent flow properties using a rotational viscometer at the temperatures of 10-60 (0)C. The samples subjected to a programmed shear rate increase linearly from 0 to 300 s(-1) in 3 min and successive decrease linearly shear rate from 300 s(-1) to 0 in 3 min. The roller milled fractions and WFF paste exhibited non-Newtonian pseudoplastic behavior. Difference in hysteresis loop area was observed among the roller milled fractions and WFF, being more noticeable at lower temperatures. Power law and Casson models were used to predict flow properties of samples. The power law model described well the flow behavior of the roller milled fractions and WFF at temperatures tested. Except flour (FL) fraction, consistency coefficient, m, increased with the temperature both in the forward and backward measurements. The roller milled fractions and WFF exhibited rheopectic behavior that increased viscosity with increasing the shear speed and the temperature. For all the sample tested, initial shear stress increased with increase in shear rate and temperature.

Acoustic of monolithic dome structures

Directory of Open Access Journals (Sweden)

Mostafa Refat Ismail

2018-03-01

The interior of monolithic domes have perfect, concave shapes to ensure that sound travels through the dome and perfectly collected at different vocal points. These dome structures are utilized for domestic use because the scale allows the focal points to be positioned across daily life activities, thereby affecting the sonic comfort of the internal space. This study examines the various acoustic treatments and parametric configurations of monolithic dome sizes. A geometric relationship of acoustic treatment and dome radius is established to provide architects guidelines on the correct selection of absorption needed to maintain the acoustic comfort of these special spaces.

Armed rollers: does nestling's vomit function as a defence against predators?

Directory of Open Access Journals (Sweden)

Deseada Parejo

Full Text Available Chemical defences against predators are widespread in the animal kingdom although have been seldom reported in birds. Here, we investigate the possibility that the orange liquid that nestlings of an insectivorous bird, the Eurasian roller (Coracias garrulus, expel when scared at their nests acts as a chemical defence against predators. We studied the diet of nestling rollers and vomit origin, its chemical composition and deterrent effect on a mammal generalist predator. We also hypothesized that nestling rollers, as their main prey (i.e. grasshoppers do from plants, could sequester chemicals from their prey for their use. Grasshoppers, that also regurgitate when facing to a threat, store the harmful substances used by plants to defend themselves against herbivores. We found that nestling rollers only vomit after being grasped and moved. The production of vomit depended on food consumption and the vomit contained two deterrent chemicals (hydroxycinnamic and hydroxybenzoic acids stored by grasshoppers and used by plants to diminish herbivory, suggesting that they originate from the rollers' prey. Finally, we showed for the first time that the oral secretion of a vertebrate had a deterrent effect on a model predator because vomit of nestling rollers made meat distasteful to dogs. These results support the idea that the vomit of nestling rollers is a chemical defence against predators.

Late Quaternary deformation of the Longquan anticline in the Longmenshan thrust belt, eastern Tibet, and its tectonic implication

Science.gov (United States)

Li, Kang; Xu, Xi-Wei; Tan, Xi-Bin; Chen, Gui-Hua; Xu, Chong; Kang, Wen-Jun

2015-11-01

The 2008 Mw 7.9 Wenchuan earthquake and 2013 Mw 6.6 Lushan earthquake are a consequence of ongoing India-Tibet collision and reflect the growth of the Longmenshan thrust belt (LSTB). Assessing seismic hazards associated with the Longquan anticline and its contribution to crustal shortening of the LSTB requires understanding of its fold structure and activity. To address this, the geometry of fluvial terraces across the anticline was surveyed and measured by real-time kinematic (RTK), and these terraces were dated by using radiocarbon with accelerator mass spectrometry (AMS) and optical stimulated luminescence (OSL) methods. Interpretation of seismic reflection profiles suggest that the Longquan anticline grows laterally through kink-band migration and a total cumulative shortening is about 1.13 km in NW-SE direction. Combining with previous studies of depth of decollement, this yields a crustal shortening rate of ∼1.47 mm/yr in NW-SE direction and constrains the time of initiation of the Longquan anticline deformation to 1-2 Ma in the late Pliocene. Obviously, our result indicate that the Longquan anticline is active and potentially seismogenic, and that it should be incorporated into current regional seismic hazard models for the highly populated area of Sichuan basin.

48 CFR 225.7009 - Restriction on ball and roller bearings.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Restriction on ball and roller bearings. 225.7009 Section 225.7009 Federal Acquisition Regulations System DEFENSE ACQUISITION... roller bearings. ...

A Methodology of Designing the Teeth Conjugation in a Planetary Roller Screw

Directory of Open Access Journals (Sweden)

Lisowski Filip

2016-12-01

Full Text Available The paper presents the methodology for designing the teeth conjunction of planetary gears in the planetary roller screw mechanism. A function of the planetary gears is to synchronize an operation of rollers in order to avoid axial displacements. A condition of the correct operation is no axial movement of rollers in relation to the nut. The planetary gears are integral parts of rollers and therefore an operation of the gear transmissions has a direct impact on cooperation of the screw, rollers and the nut. The proper design of gear engagements is essential for reducing slippage on surfaces of the cooperating threaded elements. For this purpose, in a designing method, both the limitations of operation and kinematic conditions of rollers’ operation have to be taken into account.

Skateboarding: more dangerous than roller skating or in-line skating.

Science.gov (United States)

Osberg, J S; Schneps, S E; Di Scala, C; Li, G

1998-10-01

To describe the circumstances, severity, and outcomes of skating-related injuries among children admitted to trauma centers. A cross-sectional comparison of roller skaters (n = 154), in-line skaters (n = 190), and skateboarders (n = 254) aged 5 to 19 years who were hospitalized with injuries. Seventy-nine hospitals and pediatric trauma centers participating in the National Pediatric Trauma Registry between October 1988 and April 1997. Three quarters (75.8%) of the study sample were male, nearly half (47.8%) were injured on roads, and more than one third (37.1%) had head injuries. Among skateboarders, 50.8% had head injuries compared with 33.7% of in-line skaters and 18.8% of roller skaters (Pskateboarders were 8 times more likely to be severe or critical compared with roller skaters' injuries and more than 2 times as likely to be severe or critical compared with in-line skaters' injuries. Mean hospital length of stay was 6.0 days for skateboarders, 3.4 days for in-line skaters, and 2.4 days for roller skaters (PSkateboarders were more likely to be male and to be injured on roads than were in-line skaters or roller skaters. Skateboarding-related injuries are more severe and have more serious consequences than roller skating or in-line skating injuries. Research is needed to identify ergonomic and behavioral factors responsible for higher head injury risk to skateboarders, and interventions are needed to reduce the risk.

Structural analysis of the Tabaco anticline, Cerrejón open-cast coal mine, Colombia, South America

Science.gov (United States)

Cardozo, Néstor; Montes, Camilo; Marín, Dora; Gutierrez, Iván; Palencia, Alejandro

2016-06-01

The Tabaco anticline is a 15 km long, south plunging, east-vergent anticline in northern Colombia, close to the transpressional collisional margin between the Caribbean and South American plates. In the Cerrejón open-cast coal mine, systematic mapping of coal seams in the middle to upper Paleocene Cerrejón Formation has yielded an exceptional dataset consisting of 10 horizontal slices (sea level to 90 m elevation, regularly spaced at 10 m intervals) through the anticline. Coal seams and fault traces in these slices are used to construct a 3D model of the anticline. This 3D model shows tighter folds within lower coal seams, NW-vergent thrusts and related folds on the gentler western limb, and strike-slip faults on the steeper eastern limb. Fault slip-tendency analysis is used to infer that these two faulting styles resulted from two different stress fields: an earlier one consistent with thrusting and uplift of the Perijá range, and a later one consistent with strike-slip faulting (Oca, Ranchería and Samán faults). Our preferred interpretation is that the anticline developed its eastern vergence during the early stages (late Paleocene-early Eocene) of tilting of the Santa Marta massif. Later NW-vergent thrusting on the western limb (early to middle Eocene) was related to western propagation of the Perijá thrust system. These results contribute to the understanding of the structural evolution of the area. They are also a good example of the complex interplay between detachment folding, thrusting, and strike-slip faulting during the growth of a km-size fold in a transpressive setting.

Geohydrology of the Keechi, Mount Sylvan, Oakwood, and Palestine salt domes in the northeast Texas salt-dome basin

International Nuclear Information System (INIS)

Carr, J.E.; Halasz, S.J.; Peters, H.B.

1980-01-01

The salt within these domes has penetrated as much as 20,000 feet of Mesozoic and Cenozoic strata, and presently extends to within 120 to 800 feet of the land surface. The salt penetrates or closely underlies major freshwater and salinewater aquifers within the basin. To provide a safe repository for radioactive wastes within one or more of these domes, a thorough understanding of the geohydrology needs to be obtained, and the hydrologic stability of the domes needs to be established for the expected life of the storage facility. Dissolution may exist at all four candidate salt domes, possibly through contact with Cretaceous or Tertiary aquifers, or through fault systems in the vicinity of the domes. Strata overlying and surrounding Palestine and Keechi Salt Domes have been arched into steeply-dipping folds that are complexly faulted. Similar conditions exist at Oakwood and Mount Sylvan Domes, except that the Tertiary strata have been only moderately disturbed. Additional problems concerning the hydrologic stability of Oakwood and Palestine Salt Domes have resulted from the disposal of oil-field salinewater in the cap rock at the Oakwood Dome and previous solution mining of salt at the Palestine Dome

PERSIAN DOMES: HISTORY, MORPHOLOGY AND TYPOLOGIES

Directory of Open Access Journals (Sweden)

Maryam Ashkan

2009-11-01

Full Text Available Persian master builders had introduced an architectural innovation which had an imperishable effect on dome architecture in the Middle East and Central Asia: surmounting a dome on squinches. This paper aims to provide a broader perspective of Persian domes as the most significant feature of Eastern domes in the Middle East. As opposed to previous general historic studies, this paper introduces a new analytical approach directed towards analysis of architectural concepts and stylistic attributes of Persian domes based on an epistemological premise of their space syntax. By analytic reviewing of examples, the paper addresses the origin of Persian domes, their formal morphological constitutions, and their typological forms based on the diversity of the external shell over the specific timeline, from the pre-Islamic era through the Qajar period in Iran. The study of the Persian dome’s characteristics can illustrate undiscovered information about the essences of developing dome constructions in the Middle East. It can also establish new design standards regarding the frameworks of domical building configurations to be used for creating typological diversity in dome design and to renew the morphological principles of the traditional dome compositions in contemporary architectural designs. Finally, the insights gained can inform conservation efforts on domical structures in the region and elsewhere.

Impact Analysis of Roller System Stability for Four-High Mill Horizontal Vibration

Directory of Open Access Journals (Sweden)

Xiao-bin Fan

2016-01-01

Full Text Available In order to study the hot Compact Strip Production (CSP, four-high mill vibration characteristics, and vibration suppression method, the roller system structure stability was analyzed and calculated at first in the paper. And then, the mill stand gap was measured at field and its influence on roll transverse vibration was analyzed. The drum gear coupling effect on the roller system stability and the automatic balance conditions of the coupling transmission torque were studied; the influence of axial force caused by the roller cross on the system stability was analyzed. Finally, the roller transverse friction chatter vibration mechanics model was established; the simulation analysis was carried out with eliminating mill house-bearing clearance and adding floating support for coupling, respectively. And the characteristics of the roller “jump vibration” were studied. We applied copper gaskets to eliminate or reduce mill house-bearing clearance for suppressing the rolling mill vibration on the spot; the test results show that the roller transverse vibration was suppressed after eliminating clearance.

Lunar domes properties and formation processes

CERN Document Server

Lena, Raffaello; Phillips, Jim; Chiocchetta, Maria Teresa

2013-01-01

Lunar domes are structures of volcanic origin which are usually difficult to observe due to their low heights. The Lunar Domes Handbook is a reference work on these elusive features. It provides a collection of images for a large number of lunar domes, including telescopic images acquired with advanced but still moderately intricate amateur equipment as well as recent orbital spacecraft images. Different methods for determining the morphometric properties of lunar domes (diameter, height, flank slope, edifice volume) from image data or orbital topographic data are discussed. Additionally, multispectral and hyperspectral image data are examined, providing insights into the composition of the dome material. Several classification schemes for lunar domes are described, including an approach based on the determined morphometric quantities and spectral analyses. Furthermore, the book provides a description of geophysical models of lunar domes, which yield information about the properties of the lava from which the...

Pediatric fractures during skateboarding, roller skating, and scooter riding.

Science.gov (United States)

Zalavras, Charalampos; Nikolopoulou, Georgia; Essin, Daniel; Manjra, Nahid; Zionts, Lewis E

2005-04-01

Skateboarding, roller skating, and scooter riding are popular recreational and sporting activities for children and adolescents but can be associated with skeletal injury. The purpose of this study is to describe the frequency and characteristics of fractures resulting from these activities. Fractures from skateboarding, roller skating, and scooter riding compose a considerable proportion of pediatric musculoskeletal injuries. Case series; Level of evidence, 4. Demographic data and injury characteristics were analyzed for all patients who presented to the pediatric fracture clinic of the level I trauma center from January 2001 to May 2002 after sustaining fractures due to skateboarding, roller skating, and scooter riding. Among a total of 2371 fractures, the authors identified 325 fractures (13.7%) that occurred during one of these activities. There were 187 patients (mean age, 13 years; 95% male) who sustained 191 skateboard-related fractures, 64 patients (mean age, 10.8 years; 54% male) who sustained 65 fractures while roller skating, and 66 patients (mean age, 9.7 years; 64% male) who sustained 69 fractures while riding a scooter. The forearm was fractured most often, composing 48.2% of skate-boarding fractures, 63.1% of roller-skating fractures, and 50.7% of fractures due to scooter riding. Of the forearm fractures, 94% were located in the distal third. In the skateboarding group, 10 of 191 (5.2%) fractures were open injuries of the forearm, compared to 6 of 2046 (0.3%) fractures caused by other mechanisms of injury (significant odds ratio, 18.8). Skateboarding, roller-skating, and scooter-riding accidents result in a large proportion of pediatric fractures. An open fracture, especially of the forearm, was more likely to be caused by skateboarding than by other mechanisms of injury. Use of wrist and forearm protective equipment should be considered in all children who ride a skateboard.

Geology of the north end of the Salt Valley Anticline, Grand County, Utah

International Nuclear Information System (INIS)

Gard, L.M. Jr.

1976-01-01

The geology and hydrology of a portion of the Salt Valley anticline lying north of Moab, Utah, that is being studied as a potential site for underground storage of nuclear waste in salt are discussed. Selection of this area was based on recommendations made in an earlier appraisal of the potential of Paradox basin salt deposits for such use. Salt Valley anticline, a northwest-trending diapiric structure, consists of Mesozoic sedimentary rocks arched over a thick core of salt of the Paradox Member of the Middle Pennsylvanian Hermosa Formation. Salt began to migrate to form and/or develop this structure shortly after it was deposited, probably in response to faulting. This migration caused upwelling of the salt creating a linear positive area. This positive area, in turn, caused increased deposition of sediments in adjacent areas which further enhanced salt migration. Not until late Jurassic time had flowage of the salt slowed sufficiently to allow sediments of the Morrison and younger formations to be deposited across the salt welt. A thick cap of insoluble residue was formed on top of the salt diapir as a result of salt dissolution through time. The crest of the anticline is breached; it collapsed in two stages during the Tertiary Period. The first stage was graben collapse during the early Tertiary; the second stage occurred after Miocene regional uplift had caused downcutting streams to breach the salt core resulting in further collapse. The axis of the anticline is a narrow generally flat-floored valley containing a few hills composed of downdropped Mesozoic rocks foundered in thecaprock. The caprock, which underlies thin alluvium in the valley, is composed of contorted gypsum, shale, sandstone, and limestone--the insoluble residue of the Paradox salt

Deep borehole investigations on the southwest side of the Asse anticline

International Nuclear Information System (INIS)

Klarr, K.; Kolditz, H.; Kull, H.; Schmidt, M.W.; Schweinsberg, A.; Steinberg, S.; Starke, C.; Wallmueller, R.

1990-09-01

By means of five deep borings on the south-west side of the Asse anticline, the roof rock strata series in the vicinity of the mine building erected eastwestwards, and potentials aquiferous geologic horizons were investigated. A seismic cross profile gives a survey of the whole geologic structure of the Asse salt mine. Geologic and hydrogeologic explorations of the roof rock were carried out to analyse the characteristic formation and stratification of the rock strata adjacent to the Zechstein salt anticline in respect of their water-carrying and water-impounding features, as well as the saliniferous interstratification in the Keuper, Middle Shell-lime and Upper Bunter. Geomechanic and sediment-petrographic laboratory investigations on drill cores made it possible to determine the stiffness and jointing of the roof rock strata. Using borehole measurements, rock parameters measured in situ by geophysical methods were determined and the roof rock lithology described. (HP) [de

Standard test method for measurement of web/roller friction characteristics

CERN Document Server

American Society for Testing and Materials. Philadelphia

2003-01-01

1.1 This test method covers the simulation of a roller/web transport tribosystem and the measurement of the static and kinetic coefficient of friction of the web/roller couple when sliding occurs between the two. The objective of this test method is to provide users with web/roller friction information that can be used for process control, design calculations, and for any other function where web/roller friction needs to be known. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Improvement of Railroad Roller Bearing Test Procedures & Development of Roller Bearing Diagnostic Techniques. Volume 2.

Science.gov (United States)

1982-04-01

A comprehensive review of existing basic diagnostic techniques applicable to the railcar roller bearing defect and failure problem was made. Of the potentially feasible diagnostic techniques identified, high frequency vibration was selected for exper...

Pressure Dome for High-Pressure Electrolyzer

Science.gov (United States)

Norman, Timothy; Schmitt, Edwin

2012-01-01

A high-strength, low-weight pressure vessel dome was designed specifically to house a high-pressure [2,000 psi (approx. = 13.8 MPa)] electrolyzer. In operation, the dome is filled with an inert gas pressurized to roughly 100 psi (approx. = 690 kPa) above the high, balanced pressure product oxygen and hydrogen gas streams. The inert gas acts to reduce the clamping load on electrolyzer stack tie bolts since the dome pressure acting axially inward helps offset the outward axial forces from the stack gas pressure. Likewise, radial and circumferential stresses on electrolyzer frames are minimized. Because the dome is operated at a higher pressure than the electrolyzer product gas, any external electrolyzer leak prevents oxygen or hydrogen from leaking into the dome. Instead the affected stack gas stream pressure rises detectably, thereby enabling a system shutdown. All electrical and fluid connections to the stack are made inside the pressure dome and require special plumbing and electrical dome interfaces for this to be accomplished. Further benefits of the dome are that it can act as a containment shield in the unlikely event of a catastrophic failure. Studies indicate that, for a given active area (and hence, cell ID), frame outside diameter must become ever larger to support stresses at higher operating pressures. This can lead to a large footprint and increased costs associated with thicker and/or larger diameter end-plates, tie-rods, and the frames themselves. One solution is to employ rings that fit snugly around the frame. This complicates stack assembly and is sometimes difficult to achieve in practice, as its success is strongly dependent on frame and ring tolerances, gas pressure, and operating temperature. A pressure dome permits an otherwise low-pressure stack to operate at higher pressures without growing the electrolyzer hardware. The pressure dome consists of two machined segments. An O-ring is placed in an O-ring groove in the flange of the bottom

Monitoring current rates of salt dome movement

International Nuclear Information System (INIS)

Thoms, R.L.; Manning, T.A.

1977-01-01

The tectonic stability of salt domes is a major concern for long-term domal storage of noxious wastes. A necessary phase of the many faceted dome storage study includes obtaining a measure of current vertical movement of any potential storage dome. This information then can be combined with data obtained from studies involving geologic time scales so as to provide a history of dome movement that includes present time. A system of instrumentation for monitoring current rates of dome movement is described. Complimentary finite element modelling of plausible dome movement also is presented. The proposed instrumentation system includes tiltmeters, precise levelling, laser ranging, and monitoring of microseisms. Thus, components of rotation and vertical and horizontal movements at the ground surface over a dome can be monitored. In addition, a measure of dome movement also may be obtained acoustically. The finite element modelling furnishes an aid for: (1) locating instrument sites over a dome so as to maximize instrument sensitivity, and (2) interpreting data obtained from the instrumentation system. An example of tiltmeter installation and operation over a dome in northwest Louisiana is included. Typical tiltmeter output is presented and discussed

What factors control superficial lava dome explosivity?

Science.gov (United States)

Boudon, Georges; Balcone-Boissard, Hélène; Villemant, Benoît; Morgan, Daniel J

2015-09-30

Dome-forming eruption is a frequent eruptive style and a major hazard on numerous volcanoes worldwide. Lava domes are built by slow extrusion of degassed, viscous magma and may be destroyed by gravitational collapse or explosion. The triggering of lava dome explosions is poorly understood: here we propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite precipitation. Both processes generate an impermeable and rigid carapace allowing overpressurisation of the inner parts of the lava dome by the rapid input of vesiculated magma batches. The relative thickness of the cristobalite-rich carapace is an inverse function of the external lava dome surface area. Explosive activity is thus more likely to occur at the onset of lava dome extrusion, in agreement with observations, as the likelihood of superficial lava dome explosions depends inversely on lava dome volume. This new result is of interest for the whole volcanological community and for risk management.

48 CFR 252.225-7016 - Restriction on acquisition of ball and roller bearings.

Science.gov (United States)

2010-10-01

... of ball and roller bearings. 252.225-7016 Section 252.225-7016 Federal Acquisition Regulations System... and roller bearings. As prescribed in 225.7009-5, use the following clause: Restriction on Acquisition of Ball and Roller Bearings (MAR 2006) (a) Definitions. As used in this clause' (1) Bearing...

Improving feeding powder distribution to the compaction zone in the roller compaction.

Science.gov (United States)

Yu, Mingzhe; Omar, Chalak; Schmidt, Alexander; Litster, James D; Salman, Agba D

2018-07-01

In the roller compaction process, powder flow properties have a significant influence on the uniformity of the ribbon properties. The objective of this work was to improve the powder flow in the feeding zone by developing novel feeding guiders which are located in the feeding zone close to the rollers in the roller compactor (side sealing system). Three novel feeding guiders were designed by 3D printing and used in the roller compactor, aiming to control the amount of powder passing across the roller width. The new feeding guiders were used to guide more powder to the sides between the rollers and less powder to the centre comparing to the original feeding elements. Temperature profile and porosity across the ribbon width indicated the uniformity of the ribbon properties. Using the novel feeding guiders resulted in producing ribbons with uniform temperature profile and porosity distribution across the ribbon width. The design of the feeding guiders contributed to improving the tensile strength of the ribbons produced from the compaction stage as well as reducing the fines produced from the crushing stage. Copyright © 2018 Elsevier B.V. All rights reserved.

A roller chain drive model including contact with guide-bars

DEFF Research Database (Denmark)

Pedersen, Sine Leergaard; Hansen, John Michael; Ambrósio, J. A. C.

2004-01-01

A model of a roller chain drive is developed and applied to the simulation and analysis of roller chain drives of large marine diesel engines. The model includes the impact with guide-bars that are the motion delimiter components on the chain strands between the sprockets. The main components...... and the sprocket centre, i.e. a constraint is added when such distance is less than the pitch radius. The unilateral kinematic constraint is removed when its associated constraint reaction force, applied on the roller, is in the direction of the root of the sprocket teeth. In order to improve the numerical...

Characteristics and mode of emplacement of gneiss domes and plutonic domes in central-eastern Pyrenees

Science.gov (United States)

Soula, Jean-Claude

Gneiss domes and plutonic granitoid domes make up almost 50% of the pre-Hercynian terrains in the Central and Eastern Pyrenees. From a structural study of the shape and internal structure of the domes and of their relationships with the enclosing rocks, it can be shown that both types of domes were emplaced diapirically during the major regional deformation phase and the peak of regional metamorphism. The study also shows that the internal structure, the overall shape and general behaviour relative to the host rocks are similar for plutonic domes and for gneiss domes. This appears to be in good agreement with H. Ramberg's (1967, Gravity Deformation and the Earth's Crust. Academic Press, London; 1970, Model studies in relation to intrusion of plutonic bodies. In: Mechanisms of Igneous Intrusion (edited by Newall, G. & Rast, N.) Geol. J. Spec. Issue2, 261-286.) model studies showing that dome or mushroom-like structures, similar to those observed, develop when there is a small viscosity ratio between the rising body and its enclosing medium. This implies a high crystal content for the granitoid magma. This crystal content has been estimated by (i) calculating the viscosity and density in natural conditions from petrological data for the magma considered as a suspension, using the model and program of J. P. Carron et al. (1978 Bull Soc. géol. Fr.20, 739-744.); (ii) using the recent results of experimental deformation of partially melted granites of I. van der Molen & M. S. Paterson (1979, Contr. Miner. Petrol.70, 299-318.) and (ii) comparing the preceding results with the data obtained by deformation experiments on rocks similar to those enclosing the domes. The minimum crystal content for the development of a dome-like structure has been, thus, estimated to about 70%, i.e. a value very close to that estimated by van der Molen & Paterson (1979) to be the critical value separating the granular framework flow from suspension-like behaviour. The effect of small

Environmental assessment: Richton Dome site, Mississippi

International Nuclear Information System (INIS)

1986-05-01

In February 1983, the US Department of Energy (DOE) identified the Richton Dome site in Mississippi as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Richton Dome site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. The site is in the Gulf interior region, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains two other potentially acceptable sites--the Cypress Creek Dome site in Mississippi and the Vacherie Dome site in Louisiana. Although the Cypress Creek Dome and the Vacherie Dome sites are suitable for site characterization, the DOE has concluded that the Richton Dome site is the preferred site in the Gulf interior region. On the basis of the evaluations reported in this EA, the DOE has found that the Richton Dome site is not disqualified under the guidelines

Environmental assessment: Richton Dome Site, Mississippi

Energy Technology Data Exchange (ETDEWEB)

none,

1986-05-01

In February 1983, the US Department of Energy (DOE) identified the Richton Dome site in Mississippi as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Richton Dome site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. The site is in the Gulf interior region, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains two other potentially acceptable sites--the Cypress Creek Dome site in Mississippi and the Vacherie Dome site in Louisiana. Although the Cypress Creek Dome and the Vacherie Dome sites are suitable for site characterization, the DOE has concluded that the Richton Dome site is the preferred site in the Gulf interior region. On the basis of the evaluations reported in this EA, the DOE has found that the Richton Dome site is not disqualified under the guidelines.

Environmental assessment: Richton Dome site, Mississippi

Energy Technology Data Exchange (ETDEWEB)

none,

1986-05-01

In February 1983, the US Department of Energy (DOE) identified the Richton Dome site in Mississippi as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Richton Dome site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. The site is in the Gulf interior region, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains two other potentially acceptable sites--the Cypress Creek Dome site in Mississippi and the Vacherie Dome site in Louisiana. Although the Cypress Creek Dome and the Vacherie Dome sites are suitable for site characterization, the DOE has concluded that the Richton Dome site is the preferred site in the Gulf interior region. On the basis of the evaluations reported in this EA, the DOE has found that the Richton Dome site is not disqualified under the guidelines.

Environmental assessment: Richton Dome Site, Mississippi

International Nuclear Information System (INIS)

1986-05-01

In February 1983, the US Department of Energy (DOE) identified the Richton Dome site in Mississippi as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Richton Dome site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. The site is in the Gulf interior region, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains two other potentially acceptable sites--the Cypress Creek Dome site in Mississippi and the Vacherie Dome site in Louisiana. Although the Cypress Creek Dome and the Vacherie Dome sites are suitable for site characterization, the DOE has concluded that the Richton Dome site is the preferred site in the Gulf interior region. On the basis of the evaluations reported in this EA, the DOE has found that the Richton Dome site is not disqualified under the guidelines

Site characterization plan: Gulf Coast salt domes

International Nuclear Information System (INIS)

1983-12-01

The National Waste Terminal Storage (NWTS) program of the US Department of Energy (DOE) is responsible for developing technology and providing facilities for safe, environmentally acceptable, permanent disposal of high-level nuclear waste. The Office of Nuclear Waste Isolation has been intensively investigating Gulf Coast Salt Dome Basin salt domes and bedded salt in Texas and Utah since 1978. In the Gulf Coast, the application of screening criteria in the region phase led to selection of eight domes for further study in the location phase. Further screening in the area phase identified four domes for more intensive study in the location phase: Oakwood Dome, Texas; Vacherie Dome, Louisiana; and Richton Dome and Cypress Creek Dome, Mississippi. For each dome, this Site Characterization Plan identifies specific hydrologic, geologic, tectonic, geochemical, and environmental key issues that are related to the DOE/NWTS screening criteria or affect the feasibility of constructing an exploratory shaft. The Site Characterization Plan outlines studies need to: (1) resolve issues sufficiently to allow one or more salt domes to be selected and compared to bedded salt sites in order to determine a prime salt site for an exploratory shaft; (2) conduct issue-related studies to provide a higher level of confidence that the preferred salt dome site is viable for construction of an exploratory shaft; and (3) provide a vehicle for state input to issues. Extensive references, 7 figures, 20 tables

Phylogenetic relationships of rollers (Coraciidae) based on complete mitochondrial genomes and fifteen nuclear genes.

Science.gov (United States)

Johansson, Ulf S; Irestedt, Martin; Qu, Yanhua; Ericson, Per G P

2018-04-06

The rollers (Coraciidae) constitute a relative small avian family with ca. 12 species distributed in Africa, western and southern Eurasia, and eastern Australia. In this study we examine the phylogenetic relationships of all species currently recognized in the family, including two taxa whose taxonomic status is currently contested. By using shotgun sequencing on degraded DNA from museum study skins we have been able to recover complete mitochondrial genomes as well as 15 nuclear genes for in total 16 taxa. The gene sequences were analyzed both concatenated in a maximum likelihood framework as well in a species tree approach using MP-EST. The different analytical approaches yield similar, highly supported trees and support the current division of the rollers into two genera, Coracias and Eurystomus. The only conflict relates to the placement of the Blue-bellied Roller (C. cyanogaster), where the mitochondrial, and the concatenated nuclear and mitochondrial data set, place this taxon as sister to the other Coracias species, whereas nuclear data and the species tree analysis place it as the sister taxon of C. naevia and C. spatulatus. All analyses place the Eurasian roller (C. garrulus) with the two African species, Abyssinian Roller (C. abyssinica) and Liliac-breasted Roller (C. caudatus), and place this clade as the sister group to the Asian Coracias rollers. In addition, our results support a sister group relationship between the morphologically rather dissimilar Purple Roller (C. naevia) and Racquet-tailed Roller (C. spatulatus) and also support the division of Eurystomus in an African and an Asian clade. However, within the Asian clade the Azure Roller (E. azureus) from Halmahera appears to be nested within the Dollarbird (E. orientalis), indicating that that this taxon is a morphological divergent, but a rather recent offshoot, of the widespread Dollarbird. Similarly, the Purple-winged Roller (C. temminickii) from Sulawesi group together with C. benghalensis

Cryovolcanic Emplacement of Domes on Europa

Science.gov (United States)

Quick, Lynnae C.; Glaze, Lori S.; Baloga, Stephen M.

2016-01-01

Here we explore the hypothesis that certain domes on Europa may have been produced by the extrusion of viscous cryolavas. A new mathematical method for the emplacement and relaxation of viscous lava domes is presented and applied to putative cryovolcanic domes on Europa. A similarity solution approach is applied to the governing equation for fluid flow in a cylindrical geometry, and dome relaxation is explored assuming a volume of cryolava has been rapidly emplaced onto the surface. Nonphysical sin- gularities inherent in previous models for dome relaxation have been eliminated, and cryolava cooling is represented by a time-variable viscosity. We find that at the onset of relaxation, bulk kinematic viscosities may lie in the range between 10(exp 3) and 10(exp 6) sq m/s, while the actual fluid lava viscosity may be much lower. Plausible relaxation times to form the domes, which are linked to bulk cryolava rheology, are found to range from 3.6 days to 7.5 years. We find that cooling of the cryolava, while dominated by conduction through an icy skin, should not prevent fluids from advancing and relaxing to form domes within the timescales considered. Determining the range of emplacement conditions for putative cryolava domes will shed light on Europa's resurfacing history. In addition, the rheologies and compositions of erupted cryolavas have implications for subsurface cryomagma ascent and local surface stress conditions on Europa.

Nanocrystalline, superhard, ductile ceramic coatings for roller-cone bit bearings

Energy Technology Data Exchange (ETDEWEB)

Namavar, F.; Colter, P.; Karimy, H. [Spire Corp., Bedford, MA (United States)] [and others

1997-12-31

The established method for construction of roller bits utilizes carburized steel, frequently with inserted metal bearing surfaces. This construction provides the necessary surface hardness while maintaining other desirable properties in the core. Protective coatings are a logical development where enhanced hardness, wear resistance, corrosion resistance, and surface properties are required. The wear properties of geothermal roller-cone bit bearings could be further improved by application of protective ceramic hard coatings consisting of nanometer-sized crystallites. Nanocrystalline protective coatings provide the required combination of hardness and toughness which has not been available thus far using traditional ceramics having larger grains. Increased durability of roller-cone bit bearings will ultimately reduce the cost of drilling geothermal wells through increased durability.

Geohydrolic studies of Gulf Coast interior salt domes

International Nuclear Information System (INIS)

Smith, C.G. Jr.

1977-01-01

Disposal of high-level radioactive wastes in Gulf Coast salt domes requires that the cavities be free from groundwater dissolution for 250,000 years. Salinity variations of groundwater near selected domes were investigated. Saline groundwater anomalies (saline plumes) in aquifers pierced or uplifted by the dome may be the result of salt solution by groundwater. In the Northeast Texas salt dome basin electric logs of oil and gas wells have been used to estimate groundwater salinities in aquifers near selected domes. Thus far, the analyses have revealed saline groundwater anomalies around 4 of the 9 domes studied. Estimates of the rate of salt dissolution from domes associated with saline groundwater plumes indicate that less than 30 meters of salt will be removed from the upper surfaces of the dome in 250,000 years. Thus, these preliminary studies show that even apparently unstable domes may be sufficiently stable to serve as waste disposal sites. 6 figures

What factors control the superficial lava dome explosivity?

Science.gov (United States)

Boudon, Georges; Balcone-Boissard, Hélène; Villemant, Benoit; Morgan, Daniel J.

2015-04-01

Dome-forming eruption is a frequent eruptive style; lava domes result from intermittent, slow extrusion of viscous lava. Most dome-forming eruptions produce highly microcrystallized and highly- to almost totally-degassed magmas which have a low explosive potential. During lava dome growth, recurrent collapses of unstable parts are the main destructive process of the lava dome, generating concentrated pyroclastic density currents (C-PDC) channelized in valleys. These C-PDC have a high, but localized, damage potential that largely depends on the collapsed volume. Sometimes, a dilute ash cloud surge develops at the top of the concentrated flow with an increased destructive effect because it may overflow ridges and affect larger areas. In some cases, large lava dome collapses can induce a depressurization of the magma within the conduit, leading to vulcanian explosions. By contrast, violent, laterally directed, explosions may occur at the base of a growing lava dome: this activity generates dilute and turbulent, highly-destructive, pyroclastic density currents (D-PDC), with a high velocity and propagation poorly dependent on the topography. Numerous studies on lava dome behaviors exist, but the triggering of lava dome explosions is poorly understood. Here, seven dome-forming eruptions are investigated: in the Lesser Antilles arc: Montagne Pelée, Martinique (1902-1905, 1929-1932 and 650 y. BP eruptions), Soufrière Hills, Montserrat; in Guatemala, Santiaguito (1929 eruption); in La Chaîne des Puys, France (Puy de Dome and Puy Chopine eruptions). We propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by these key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite

On Working Capacity Criteria for Screw-Roller Mechanisms

Directory of Open Access Journals (Sweden)

D. S. Blinov

2015-01-01

Full Text Available Today roller-screw mechanisms (RSM are the most prospective motion converters from rotary to linear type. RSM manufacturers have suggested their design in the way, similar to the rolling bearings, in static and dynamic load ratings. The latter means that during long operations the main criterion of the RSM working capacity is fatigue spalling. However, this approach does not permit to consider temporal changes of the most critical performance parameters of the RSM (such as the axial play, the efficiency factor, the axial stiffness, the accuracy, the starting torque force for zero lash RSMs, etc. through calculations. The abovementioned method was not perfect, because the choice of the main criterion of RSM working capacity was wrong. The article proves that wear-resistance is the main criterion of RSM working capacity. The proof is the RSM efficiency factor equal to 80-88% on the average. The power loss occurs because of overcoming a sliding friction between multiple (from 300 to 1000 interfacing turns of thread on the screw and the rollers as well as on the rollers and the nut. That is why the RSMs are the screwtype rolling mechanisms with an essential portion of sliding friction. High-accuracy measurements taken using the device called a form-tracer for threaded pieces permitted to determine the essential changes on the profiles of turns of threads on the rollers (a straight-line portion appeared on the radial profile; these changes could emerge only from wear. Besides, the length of this portion increased with the increasing RSM operation time. The JSC “Moskvich” has examined the RSMs, which have been put out of operation after completing their service life as parts of robot welding machines. There were no traces of fatigue spalling found on the threaded surfaces of the RSM parts, while the sizes of the straight-line portions on the turns of the roller threads were much bigger than they were during the measurements after the initial

An assessment of hydrothermal alteration in the Santiaguito lava dome complex, Guatemala: implications for dome collapse hazards

Science.gov (United States)

Ball, Jessica L.; Calder, Eliza S.; Hubbard, Bernard E.; Bernstein, Marc L.

2013-01-01

A combination of field mapping, geochemistry, and remote sensing methods has been employed to determine the extent of hydrothermal alteration and assess the potential for failure at the Santiaguito lava dome complex, Guatemala. The 90-year-old complex of four lava domes has only experienced relatively small and infrequent dome collapses in the past, which were associated with lava extrusion. However, existing evidence of an active hydrothermal system coupled with intense seasonal precipitation also presents ideal conditions for instability related to weakened clay-rich edifice rocks. Mapping of the Santiaguito dome complex identified structural features related to dome growth dynamics, potential areas of weakness related to erosion, and locations of fumarole fields. X-ray diffraction and backscattered electron images taken with scanning electron microscopy of dacite and ash samples collected from around fumaroles revealed only minor clay films, and little evidence of alteration. Mineral mapping using ASTER and Hyperion satellite images, however, suggest low-temperature (<150 °C) silicic alteration on erosional surfaces of the domes, but not the type of pervasive acid-sulfate alteration implicated in collapses of other altered edifices. To evaluate the possibility of internal alteration, we re-examined existing aqueous geochemical data from dome-fed hot springs. The data indicate significant water–rock interaction, but the Na–Mg–K geoindicator suggests only a short water residence time, and δ18O/δD ratios show only minor shifts from the meteoric water line with little precipitation of secondary (alteration) minerals. Based on available data, hydrothermal alteration on the dome complex appears to be restricted to surficial deposits of hydrous silica, but the study has highlighted, importantly, that the 1902 eruption crater headwall of Santa María does show more advanced argillic alteration. We also cannot rule out the possibility of advanced alteration

Thermal influences on spontaneous rock dome exfoliation

Science.gov (United States)

Collins, Brian D.; Stock, Greg M.; Eppes, Martha C.; Lewis, Scott W.; Corbett, Skye C.; Smith, Joel B.

2018-01-01

Rock domes, with their onion-skin layers of exfoliation sheets, are among the most captivating landforms on Earth. Long recognized as integral in shaping domes, the exact mechanism(s) by which exfoliation occurs remains enigmatic, mainly due to the lack of direct observations of natural events. In August 2014, during the hottest days of summer, a granitic dome in California, USA, spontaneously exfoliated; witnesses observed extensive cracking, including a ~8000 kg sheet popping into the air. Subsequent exfoliation episodes during the following two summers were recorded by instrumentation that captured—for the first time—exfoliation deformation and stress conditions. Here we show that thermal cycling and cumulative dome surface heating can induce subcritical cracking that culminates in seemingly spontaneous exfoliation. Our results indicate that thermal stresses—largely discounted in dome formation literature—can play a key role in triggering exfoliation and therefore may be an important control for shaping domes worldwide.

Observer Kalman Filter Identification of Suspen-Dome

Directory of Open Access Journals (Sweden)

Guojun Sun

2017-01-01

Full Text Available A number of Suspen-Dome structures have been built, but there is some difficulty in using experimental data to obtain good modal parameters, especially modal damping. In this paper, an ANSYS numerical simulation of the 35.4 m span Suspen-Dome is presented. Firstly, the natural vibration characteristics of Suspen-Dome and dynamic response under some random forces were obtained. Then the results of the numerical simulation established that 60 modes are sufficient for a reasonable dynamic model. This model is used to represent the Suspen-Dome dynamic behavior, and OKID is then used to try to identify a model from simulated data. A 400-order model generated from OKID is shown to contain the 60 modes from ANSYS and is shown to give good predictions of the dynamic behavior of Suspen-Dome. The results of this paper can confirm that it can be a very efficient tool for the identification of models of Suspen-Dome dynamics.

Fast EEMD Based AM-Correntropy Matrix and Its Application on Roller Bearing Fault Diagnosis

Directory of Open Access Journals (Sweden)

Yunxiao Fu

2016-06-01

Full Text Available Roller bearing plays a significant role in industrial sectors. To improve the ability of roller bearing fault diagnosis under multi-rotating situation, this paper proposes a novel roller bearing fault characteristic: the Amplitude Modulation (AM based correntropy extracted from the Intrinsic Mode Functions (IMFs, which are decomposed by Fast Ensemble Empirical mode decomposition (FEEMD and employ Least Square Support Vector Machine (LSSVM to implement intelligent fault identification. Firstly, the roller bearing vibration acceleration signal is decomposed by FEEMD to extract IMFs. Secondly, IMF correntropy matrix (IMFCM as the fault feature matrix is calculated from the AM-correntropy model of the primary vibration signal and IMFs. Furthermore, depending on LSSVM, the fault identification results of the roller bearing are obtained. Through the bearing identification experiments in stationary rotating conditions, it was verified that IMFCM generates more stable and higher diagnosis accuracy than conventional fault features such as energy moment, fuzzy entropy, and spectral kurtosis. Additionally, it proves that IMFCM has more diagnosis robustness than conventional fault features under cross-mixed roller bearing operating conditions. The diagnosis accuracy was more than 84% for the cross-mixed operating condition, which is much higher than the traditional features. In conclusion, it was proven that FEEMD-IMFCM-LSSVM is a reliable technology for roller bearing fault diagnosis under the constant or multi-positioned operating conditions, and as such, it possesses potential prospects for a broad application of uses.

Edgewise vibration control of wind turbine blades using roller and liquid dampers

DEFF Research Database (Denmark)

Zhang, Zili; Nielsen, Søren R.K.

2014-01-01

suppressing edgewise vibrations. The roller dampers are more volumetrically efficient due to the higher mass density of the steel comparing with the liquid. On the other hand, TLCDs have their advantage that it is easier to specify the optimum damping of the damper by changing the opening ratio of the orifice......This paper deals with the passive vibration control of edgewise vibrations by means of roller dampers and tuned liquid column dampers (TLCDs). For a rotating blade, the large centrifugal acceleration makes it possible to use roller dampers or TLCDs with rather small masses for effectively...

Edgewise vibration control of wind turbine blades using roller and liquid dampers

International Nuclear Information System (INIS)

Zhang, Z L; Nielsen, S R K

2014-01-01

This paper deals with the passive vibration control of edgewise vibrations by means of roller dampers and tuned liquid column dampers (TLCDs). For a rotating blade, the large centrifugal acceleration makes it possible to use roller dampers or TLCDs with rather small masses for effectively suppressing edgewise vibrations. The roller dampers are more volumetrically efficient due to the higher mass density of the steel comparing with the liquid. On the other hand, TLCDs have their advantage that it is easier to specify the optimum damping of the damper by changing the opening ratio of the orifice. In this paper, 2-DOF nonlinear models are suggested for tuning a roller damper or a TLCD attached to a rotating wind turbine blade, ignoring the coupling between the blade and the tower. The decoupled optimization is verified by incorporating the optimized damper into a more sophisticated 13- DOF wind turbine model with due consideration of the coupled blade-tower-drivetrain vibrations, quasi-static aeroelasticity as well as a collective pitch controller. Performances of the dampers are compared in terms of the control efficiency and the practical applications. The results indicate that roller dampers and TLCDs at optimal tuning can effectively suppress the dynamic response of wind turbine blades

Daylighting performance evaluation of a bottom-up motorized roller shade

Energy Technology Data Exchange (ETDEWEB)

Kapsis, K.; Athienitis, A.K.; Zmeureanu, R.G. [Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC (Canada); Tzempelikos, A. [School of Civil Engineering, Purdue University, West Lafayette, IN (United States)

2010-12-15

This paper presents an experimental and simulation study for quantifying the daylighting performance of bottom-up roller shades installed in office spaces. The bottom-up shade is a motorized roller shade that opens from top to bottom operating in the opposite direction of a conventional roller shade, so as to cover the bottom part of the window, while allowing daylight to enter from the top part of the window, reaching deeper into the room. A daylighting simulation model, validated with full-scale experiments, was developed in order to establish correlations between the shade position, outdoor illuminance and work plane illuminance for different outdoor conditions. Then, a shading control algorithm was developed for application in any location and orientation. The validated model was employed for a sensitivity analysis of the impact of shade optical properties and control on the potential energy savings due to the use of daylighting. The results showed that Daylight Autonomy for the bottom-up shade is 8-58% higher compared to a conventional roller shade, with a difference of 46% further away from the facade, where the use of electric lighting is needed most of the time. The potential reduction in energy consumption for lighting is 21-41%. (author)

INFLUENCE CONSTRUCTION OF THE ROLLER ON THE POWER OF THE DRIVE SYSTEM OF THE BELT CONVEYOR

Directory of Open Access Journals (Sweden)

Tadeusz OPASIAK

2014-09-01

Full Text Available The paper presents a study of new design of rollers. The study focused on the measurement of static and dynamic resistance of rotating rollers and the impact of new construction on the power consumption of the belt conveyor. Rollers have been modified through the use of class C4 bearing seals and labyrinth seal U4Exp 62/65 with a cover 2LU4 of runner construction. Measurements of static and dynamic resistance of rotating rollers were made on a universal rollers stand and power measurements were carried out on a belt conveyor power supply system Gwarek 1200 No. TW in mine KWK Mysłowice–Wesoła.

Geothermal studies of seven interior salt domes

International Nuclear Information System (INIS)

1983-06-01

This report defines and compares the geothermal environments of eight selected Gulf Coast salt domes. The thermal regimes in and around Gulf Coast salt domes are not well documented. The data base used for this study is an accumulation of bottom-hole temperature readings from oil and gas exploration wells and temperature logs run for the National Waste Terminal Storage (NWTS) program. The bottom-hole tempreatures were corrected in order to estimate the actual geothermal environments. Prior thermal studies and models indicate temperatures in and around salt domes are elevated above the norm by 1 0 F to 25 0 F. Using existing geothermal data and accepted theory, geothermal gradients for the selected domes and surrounding sediments were estimated. This study concludes that salt domes within a given basin have similar geothermal gradients, but that the basins differ in average geothermal gradients. This relationship is probably controlled by deep basement structural trends. No evidence of residual heat of emplacement was found associated with any of the selected domes

PENGEMBANGAN DESA WISATA RUMAH DOME BERBASIS AGROINDUSTRI PANGAN LOKAL (Kajian Diversifikasi Ketela Pohon di Desa Wisata Rumah Dome Prambanan

Directory of Open Access Journals (Sweden)

Susi Wuri Ani

2013-11-01

Full Text Available Pangan merupakan kebutuhan utama dalam kehidupan manusia. Pemenuhan kebutuhan pangan baik dari segi jumlah, mutu, gizi maupun keamanan berkaitan dengan Sumberdaya Manusia (SDM. Kualitas konsumsi pangan dan gizi masyarakat menentukan SDM masyarakat tersebut. Agroindustri pangan lokal merupakan kegiatan yang memberdayakan sumberdaya lokal (indigenous resources. Seluruh potensi lokal dimanfaatkan untuk menguatkan agroindustri pangan lokal. Penduduk di kawasan wisata Rumah Dome belum mampu mengolah bahan pangan lokal. Kegiatan ini bertujuan membentuk kelompok usaha produktif Ibu-Ibu PKK di Rumah Dome untuk dapat meningkatkan nilai ekonomis pangan lokal (ketela pohon. Hal yang dilakukan adalah memberikan pelatihan pengolahan ketela pohon menjadi ceriping singkong berbagai rasa, keripik belut daun singkong, membuat brownies berbahan tepung ketela, mengemas produk dengan brand Rumah Dome dan memberikan pelatihan pembukuan sederhana. Dengan kegiatan ini diharapkan akan tumbuh kelompok usaha produktif sehingga dapat mengangkat citra wisata Rumah Dome dan meningkatkan pendapatan masyarakat di Rumah Dome. Abstract Food is a major necessity in human life. Food needs are important for human resource (HR both in terms of quantity and quality. Quality of food consumption and nutrition communities determine the HR community. Local food agroindustry is an activity that empowers local resources (indigenous resources. The whole potential of local food used to strengthen local agroindustry. Residents in the tourist area of Dome House have not been able to process local food. This activity aims to establish productive business of woman group (PKK in Dome House to increase the economic value of local food (cassava. The activities are training for production process, packaging with Dome House’s brand and simple accounting management. The cassava processing training are: (1 making variety flavors of cassava chips; (2 producing eel chips from cassava leaves and (3

Roller compaction: Effect of relative humidity of lactose powder.

Science.gov (United States)

Omar, Chalak S; Dhenge, Ranjit M; Palzer, Stefan; Hounslow, Michael J; Salman, Agba D

2016-09-01

The effect of storage at different relative humidity conditions, for various types of lactose, on roller compaction behaviour was investigated. Three types of lactose were used in this study: anhydrous lactose (SuperTab21AN), spray dried lactose (SuperTab11SD) and α-lactose monohydrate 200M. These powders differ in their amorphous contents, due to different manufacturing processes. The powders were stored in a climatic chamber at different relative humidity values ranging from 10% to 80% RH. It was found that the roller compaction behaviour and ribbon properties were different for powders conditioned to different relative humidities. The amount of fines produced, which is undesirable in roller compaction, was found to be different at different relative humidity. The minimum amount of fines produced was found to be for powders conditioned at 20-40% RH. The maximum amount of fines was produced for powders conditioned at 80% RH. This was attributed to the decrease in powder flowability, as indicated by the flow function coefficient ffc and the angle of repose. Particle Image Velocimetry (PIV) was also applied to determine the velocity of primary particles during ribbon production, and it was found that the velocity of the powder during the roller compaction decreased with powders stored at high RH. This resulted in less powder being present in the compaction zone at the edges of the rollers, which resulted in ribbons with a smaller overall width. The relative humidity for the storage of powders has shown to have minimal effect on the ribbon tensile strength at low RH conditions (10-20%). The lowest tensile strength of ribbons produced from lactose 200M and SD was for powders conditioned at 80% RH, whereas, ribbons produced from lactose 21AN at the same condition of 80% RH showed the highest tensile strength. The storage RH range 20-40% was found to be an optimum condition for roll compacting three lactose powders, as it resulted in a minimum amount of fines in the

Dissolution of the Mors salt dome

International Nuclear Information System (INIS)

Lindstroem Jensen, K.E.

1982-01-01

Regardless of the interpretation of the measured salinity profiles above the Mors salt dome, they can at most be the result of dissolution rates of about 0.004 mm per year. This means that it would take more than 2.5 mill. years to dissolve 10 m of salt. Variations in groun water velocity and cap rock porosity will not significantly change this condition. The stability of the Mors salt dome is therefore not affected by dissolution of the dome. (EG)

The System of Simulation and Multi-objective Optimization for the Roller Kiln

Science.gov (United States)

Huang, He; Chen, Xishen; Li, Wugang; Li, Zhuoqiu

It is somewhat a difficult researching problem, to get the building parameters of the ceramic roller kiln simulation model. A system integrated of evolutionary algorithms (PSO, DE and DEPSO) and computational fluid dynamics (CFD), is proposed to solve the problem. And the temperature field uniformity and the environment disruption are studied in this paper. With the help of the efficient parallel calculation, the ceramic roller kiln temperature field uniformity and the NOx emissions field have been researched in the system at the same time. A multi-objective optimization example of the industrial roller kiln proves that the system is of excellent parameter exploration capability.

Design, development and evaluation of a divergent roller sizer for almond kernels

Directory of Open Access Journals (Sweden)

D Ghanbarian

2015-09-01

Full Text Available Introduction: Iran is one of the major producers of almonds. According to the statistics released by FAO (2011, Iran with more than 110000 tons of almonds is the third in rank throughout the world. However, most Iranian almonds are presented as an unsorted and unpackaged product. Some producers sort their products by hand which is very time-consuming and labor-intensive. So, there is an essential need for suitable grading and packaging machines especially for the export of almond kernels.Grading, which is sometimes called sorting, is basically separating the material in different homogenous groups according to its specific characteristics like size, shape, color and on the basis of quality. Weighing is one of the best methods for grading agricultural products based on size, but due to its high cost and complexity of operations, usage of weigh size sorting machines is practically limited. So, sizing of most agricultural products is accomplished based on their dimensional attributes such as diameter, length, thickness or a combination of them. Field study shows that recently vibrating sizing machines are used for grading almond kernels. This type of sizing machine is huge, expensive, noisy and it consumes a lot of energy. Thus, the main objective of the present study was the design, development and evaluation of a new prototype of an almond kernel sizing machine. Materials and methods: It is important that the machine could resolve defects of existing vibrating machines. It should provide efficient and cost effective sizing for a wide range of kernel sizes and shapes. Furthermore, it should be of simple construction and be able to accept manual feeding. Previously conducted experiments showed that the thickness of the kernel is the most appropriate dimension for its sizing. Among the different types of dimensional sizing machines, the divergent roller grader which grades the products based on their thickness is considered to be one of the simplest

Roller Skating; Physical Education: 9.8414.

Science.gov (United States)

Amacker, Kathy; Mikell, Lenora

GRADES OR AGES: Grades 7-12. SUBJECT MATTER: Methods and procedures of roller skating. ORGANIZATION AND PHYSICAL APPEARANCE: The contents are divided into six areas, which are Course Guidelines, Course Description and Accreditation Standard Broad Goal, Course of Study Behavioral Objectives, Course Content, Learning Activities and Teaching…

Knee joint position sense of roller hockey players: a comparative study.

Science.gov (United States)

Venâncio, João; Lopes, Diogo; Lourenço, Joaquim; Ribeiro, Fernando

2016-06-01

This study aimed to compare knee joint position sense of roller hockey players with an age-matched group of non-athletes. Forty-three male participants voluntarily participated in this cross-sectional study: 21 roller hockey players (mean age: 23.2 ± 4.2 years old, mean weight: 81.8 ± 9.8 kg, mean height: 180.5 ± 4.1 cm) and 22 age-matched non-athletes (mean age: 23.7 ± 3.9 years old, mean weight: 85.0 ± 6.2 kg, mean height: 181.5 ± 5.0 cm). Knee joint position sense of the dominant limb was evaluated using a technique of open-kinetic chain and active knee positioning. Joint position sense was reported using absolute, relative and variable angular errors. The main results indicated that the group of roller hockey players showed significantly lower absolute (2.4 ± 1.2º vs. 6.5 ± 3.2º, p ≤ 0.001) and relative (1.7 ± 2.1º vs. 5.8 ± 4.4º, p ≤ 0.001) angular errors in comparison with the non-athletes group. In conclusion, the results from this present study suggest that proprioceptive acuity, assessed by measuring joint position sense, is increased in roller hockey players. The enhanced proprioception of the roller hockey players could contribute to injury prevention and improved performance during sporting activities.

Modelling of a mecanum wheel taking into account the geometry of road rollers

Science.gov (United States)

Hryniewicz, P.; Gwiazda, A.; Banaś, W.; Sękala, A.; Foit, K.

2017-08-01

During the process planning in a company one of the basic factors associated with the production costs is the operation time for particular technological jobs. The operation time consists of time units associated with the machining tasks of a workpiece as well as the time associated with loading and unloading and the transport operations of this workpiece between machining stands. Full automation of manufacturing in industry companies tends to a maximal reduction in machine downtimes, thereby the fixed costs simultaneously decreasing. The new construction of wheeled vehicles, using Mecanum wheels, reduces the transport time of materials and workpieces between machining stands. These vehicles have the ability to simultaneously move in two axes and thus more rapid positioning of the vehicle relative to the machining stand. The Mecanum wheel construction implies placing, around the wheel free rollers that are mounted at an angle 450, which allow the movement of the vehicle not only in its axis but also perpendicular thereto. The improper selection of the rollers can cause unwanted vertical movement of the vehicle, which may cause difficulty in positioning of the vehicle in relation to the machining stand and the need for stabilisation. Hence the proper design of the free rollers is essential in designing the whole Mecanum wheel construction. It allows avoiding the disadvantageous and unwanted vertical vibrations of a whole vehicle with these wheels. In the article the process of modelling the free rollers, in order to obtain the desired shape of unchanging, horizontal trajectory of the vehicle is presented. This shape depends on the desired diameter of the whole Mecanum wheel, together with the road rollers, and the width of the drive wheel. Another factor related with the curvature of the trajectory shape is the length of the road roller and its diameter decreases depending on the position with respect to its centre. The additional factor, limiting construction of

75 FR 53980 - Notice of Rescheduled Meetings of the Pinedale Anticline Working Group

Science.gov (United States)

2010-09-02

... Pinedale Anticline Project Area (PAPA) on July 27, 2000 and carried forward with the release of the ROD for the PAPA Supplemental Environmental Impact Statement (SEIS) on September 12, 2008. The PAWG is a... on mitigation, monitoring, and adaptive management issues as oil and gas development in the PAPA...

Case histories of roller cone core bit application in crystalline rock

International Nuclear Information System (INIS)

Dahlem, J.S.

1988-01-01

The increased interest in deep crystalline rock drilling projects has resulted in a requirement for premium coring bits which are effective in such a harsh and abrasive environment. Hard formation roller cone insert bits have traditionally and constantly performed well in crystalline rock. As a result, the application of state of the art roller cone rock bit technology to the design and development of core bits has made crystalline coring projects more viable than ever before. This paper follows the development of roller cone core bits by examining their use on project such as HDR (Hot Dry Rock, Los Alamos); NAGRA (Nuclear Waste Disposal Wells in Switzerland); Camborne School of Mines Geothermal Project in Cornwall, UK; Deep Gas Project in Sweden; and the KTB Deep Drilling Project in West Germany

IRON DOME

African Journals Online (AJOL)

6 Israeli Navy 'First Arm of the Sea: The Successful Interception of the Iron Dome Rocket .... sky to destroy them whilst in flight to minimise civilian casualties. ..... Including The Moon and Celestial Bodies.53 Demeyere further emphasises the.

Dropping a particle out of a roller coaster

International Nuclear Information System (INIS)

Mungan, Carl E; Lipscombe, Trevor C

2014-01-01

A rider in a roller coaster lets go of a particle such as a small marble. How far does the marble travel horizontally from the point of release before hitting the ground, assuming the speed of the roller coaster is determined by conservation of mechanical energy starting from the highest hill up which it was pulled? Where should the marble be released along the track if one wishes to maximize the range of the marble? These questions constitute interesting variations on conventional problems in two-dimensional kinematics, appropriate for an undergraduate course in classical mechanics. Exploration of various shapes of tracks could form interesting student projects for numerical or experimental investigation. (paper)

3000-HP Roller Gear Transmission Development Program. Volume 3. Roller Gear Manufacture

Science.gov (United States)

1975-07-01

power is fed through the ramp roller clutch type free- wheel units to spur gears which mesh with the combining spur gear whose centerline is common...when the engine tends to turn faster than the main rotor shaft. It is in the free- wheel mode when the main rotor shaft tends to turn faster than the...gears are cut progrind at this time. Check face runout on each end of largo gears. Not to exceed .002" TIR 30 EBW one end 40 EBW opposite end

Temperature and Thermal Expansion Analysis of the Cooling Roller Based on the Variable Heat Flux Boundary Condition

Science.gov (United States)

Li, Yongkang; Yang, Yang; He, Changyan

2018-06-01

Planar flow casting (PFC) is a primary method for preparing an amorphous ribbon. The qualities of the amorphous ribbon are significantly influenced by the temperature and thermal expansion of the cooling roller. This study proposes a new approach to analyze the three-dimensional temperature and thermal expansion of the cooling roller using variable heat flux that acted on the cooling roller as a boundary condition. First, a simplified two-dimensional model of the PFC is developed to simulate the distribution of the heat flux in the circumferential direction with the software FLUENT. The resulting heat flux is extended to be three-dimensional in the ribbon's width direction. Then, the extended heat flux is imported as the boundary condition by the CFX Expression Language, and the transient temperature of the cooling roller is analyzed in the CFX software. Next, the transient thermal expansion of the cooling roller is simulated through the thermal-structural coupling method. Simulation results show that the roller's temperature and expansion are unevenly distributed, reach the peak value in the middle width direction, and the quasi-steady state of the maximum temperature and thermal expansion are achieved after approximately 50 s and 150 s of casting, respectively. The minimum values of the temperature and expansion are achieved when the roller has a thickness of 45 mm. Finally, the reliability of the approach proposed is verified by measuring the roller's thermal expansion on the spot. This study provides theoretical guidance for the roller's thermal expansion prediction and the gap adjustment in the PFC.

Modelling and simulation of dynamic wheel-rail interaction using a roller rig

International Nuclear Information System (INIS)

Anyakwo, A; Pislaru, C; Ball, A; Gu, F

2012-01-01

The interaction between the wheel and rail greatly influences the dynamic response of railway vehicles on the track. A roller rig facility can be used to study and monitor real time parameters that influence wheel-rail interaction such as wear, adhesion, friction and corrugation without actual field tests being carried out. This paper presents the development of the mathematical models for full scale roller rig and 1/5 scale roller rig and the wear prediction model based on KTH wear function. The simulated critical speed for the 1/5 scale roller rig is about one-fifth of the critical speed for the full scale model so the simulated results compare well with the theory related to wheel-rail contact and dynamics. Also the differences between the simulated rolling radii for the full scale model with and without wear function are analysed. This paper presents the initial stage of a large scale research project where the influence of wear on the wheel-rail performance will be studied in more depth.

ANALYSIS OF MOVEMENT RESISTANCE OF CONVEYOR BELT AND ROLLERS IN THE COAL MINE MYSŁOWICE-WESOŁA

Directory of Open Access Journals (Sweden)

Tadeusz OPASIAK

2014-03-01

Full Text Available The paper presents a study of new design of SAG rollers. The study focused on the measurement of static and dynamic resistance of rotating rollers and the impact of new construction on the power consumption of the conveyor. Rollers have been modified through the use of class C4 bearing seals and labyrinth seal U4Exp 62/65 with a cover 2LU4 of runner construction. Measurements of static and dynamic resistance of rotating rollers were made on a universal rollers test bench, and power measurements were carried out on a belt conveyor power supply system Gwarek 1200 No. TW in KWK Mysłowice-Wesoła

Midyear FY 1983 Richton Dome screening and suitability review

International Nuclear Information System (INIS)

1983-08-01

The NWTS screening of Gulf Coast salt domes for suitable nuclear waste repository sites identified three candidate domes. These are, in order of preference, Richton Dome, Mississippi; Vacherie Dome, Louisiana; and Cypress Creek Dome, Mississippi. A qualitative review of information obtained since this initial ranking gives no basis for revising this ranking. A review of unresolved siting issues at Richton Dome shows siting concerns presently center on the geologic stability and hydrology suitability of Richton Dome and vicinity. Tectonic concerns of regional uplift and faulting are examined, as are salt tectonic concerns related to salt dome movement and dissolution. Both geologic and geodetic data suggest the Mississippi Salt Basin is experiencing uplift. However, uplift rates estimated from geologic evidence are an order of magnitude less than rates estimated from releveling data. Faults are present throughout much of the basin, and most are the result of horizontal and vertical movements of the Louann Salt during the Cretaceous and Early Tertiary. Several faults are present in the sediments surrounding Richton Dome, but current evidence suggests no movements have occurred since the Miocene. Richton Dome's hydrologic suitability is considered in analysis of the regional ground-water flow system. A three-dimensional, ground-water flow model has been utilized to calculate travel paths and travel times for releases of contaminants from various points on the dome. Based on model analyses, a release at repository level would take nearly 39,000 years to reach the upper aquifer and would eventually discharge into the Leaf River or upper reaches of the Pascagoula River over 50 km from the dome. This estimate of travel time greatly exceeds the minimum 1000 year travel time required by proposed Department of Energy (DOE) guidelines. 76 references

Arc jet testing of a Dynasil dome

Science.gov (United States)

Burrell, Jack O.; Strobel, Forrest A.

1999-07-01

Arc jet testing of the Hera modified ballistic reentry vehicle - 1E (MBRV-1E) nosetip was conducted in June of 1998. The tests were conducted in the Air Force's Arnold Engineering Development Center HEAT-H1 arc plasma test facility in Tullahoma, Tennessee. The MBRV-1 vehicle is a separating short- to medium-range target. The MBRV-1E nosetip incorporates a custom designed quartz dome that is integrated into the nosetip stagnation region. The dome was bonded to the baseline nosetip material, a well characterized carbon-carbon composite material, using a silica based ceramic bond materials. The objectives of the test were to demonstrate the thermal performance and structural integrity of the nosetip design by exposing tip to arc plasma-heated flow simulating the reentry flight environment. Pre-test analysis of the Dynasil dome performed using finite element analysis predicted the dome would survive the test conditions with no failures. Post-test inspection of the dome revealed a hard, opaque coating on the outer surface of the dome. Once removed, the dome was shown to have numerous surface cracks near the stagnation region. In addition to the surface cracks, significant pitting on the surface was observed through both an optical microscope and a scanning electron microscope. Post-test analyses were performed to determine the cause of these surface cracks. It was concluded that the cracks occurred during cooldown, and were a result of significant strength degradation which was caused by the surface pitting.

Geology of the north end of the Salt Valley Anticline, Grand County, Utah

Science.gov (United States)

Gard, Leonard Meade

1976-01-01

This report describes the geology and hydrology of a portion of the Salt Valley anticline lying north of Moab, Utah, that is being studied as a potential site for underground storage of nuclear waste in salt. Selection of this area was based on recommendations made in an earlier appraisal of the potential of Paradox basin salt deposits for such use. Part of sec. 5, T. 23 S., R. 20 E. has been selected as a site for subsurface investigation as a potential repository for radioactive waste. This site has easy access to transportation, is on public land, is isolated from human habitation, is not visible from Arches National Park, and the salt body lies within about 800 feet (244 m) of the surface. Further exploration should include investigation of possible ground water in the caprock and physical exploration of the salt body to identify a thick bed of salt for use as a storage zone that can be isolated from the shaly interbeds that possibly contain quantities of hydrocarbons. Salt Valley anticline, a northwest-trending diapiric structure, consists of Mesozoic sedimentary rocks arched over a thick core of salt of the Paradox Member of the Middle Pennsylvanian Hermosa Formation. Salt began to migrate to form and/or develop this structure shortly after it was deposited, probably in response to faulting. This migration caused upwelling of the salt creating a linear positive area. This positive area, in turn, caused increased deposition of sediments in adjacent areas which further enhanced salt migration. Not until late Jurassic time had flowage of the salt slowed sufficiently to allow sediments of the Morrison and younger formations to be deposited across the salt welt. A thick cap of insoluble residue was formed on top of the salt diapir as a result of salt dissolution through time. The crest of the anticline is breached; it collapsed in two stages during the Tertiary Period. The first stage was graben collapse during the early Tertiary; the second stage occurred after

Site specific study for possible ongoing salt dome movement

International Nuclear Information System (INIS)

Thoms, R.L.; Manning, T.A.; Paille, L.K.; Gehle, R.M.

1977-01-01

U.S. Gulf Coast salt domes, among other geologic structures, currently are being considered for storage of commercial radioactive wastes. A major concern with dome storage of long lived radioactive wastes lies with the possible tectonic movement of the host dome. Any ongoing movement of a salt dome can be monitored with a site specific complementary system of field instrumentation and finite element modelling. Field instrumentation and accompanying finite element analyses for a study dome in northwest Louisiana are described. Site specific data and early experience associated with tiltmeters over the dome are presented. Also, recommendations are made for modifications and extensions of the field instrumentation and finite element modelling appropriate to the specific site under study

Building Guastavino dome in China: A historical survey of the dome of the Auditorium at Tsinghua University

Directory of Open Access Journals (Sweden)

Yishi Liu

2014-06-01

The first part combs up the intellectual origins and precedents of the campus planning by Henry Murphy. As the dome is a focal point of the study, a brief course on the history of dome construction in the West is needed. The third part, based upon field measurement in July 2013, compares the actual dome with its original design featured by the Guastavino method, deducing possible reasons that resulted in the differences, including architect׳s unfamiliarity with Guastavino Company and its parameters, considerations about cost, and local construction tradition.

Rock 'n roller coaster : an explorative study on the evolution of the European steel roller coaster industry

NARCIS (Netherlands)

Timmermans, B.; Bekkers, R.N.A.; Bordoli, L.

2012-01-01

This article investigates the 50 years evolution of the European steel roller coaster industry, which can be classified as a complex products systems (CoPS) industry. This industry is characterized as a non-shake out industry where entry can be divided in three waves, i.e. early diversifiers, new

Cost of a roller skating rink to the local accident and emergency department.

Science.gov (United States)

Nayeem, N; Shires, S E; Porter, J E

1990-01-01

A 14 month retrospective study was undertaken to determine the cost implications of the opening of a roller skating rink to the local hospital accident and emergency department (A and E). A total of 398 patients attended following injury at the roller skating rink, of whom 384 were included in the study. The estimated cost of their injuries was determined by the hospital accounts department. The average cost per patient attending the A and E department following roller skating injury was about 100 pounds. The total cost to the A and E department of all injuries sustained at the rink over this period was 38,412 pounds. The cost implications of opening a roller skating rink for the A and E department are considerable. If proposals for self-budgeting are applied, A and E departments will have to seek additional funding if such leisure facilities are opened in their vicinity. PMID:2097020

Influence of Surface-profile and Movement-path of Roller on Thickness Thinning during Multi-pass Deep Drawing Spinning

Directory of Open Access Journals (Sweden)

Xia Qinxiang

2016-01-01

Full Text Available Over thinning is a serious defect influencing the forming quality of spun workpiece during multi-pass deep drawing spinning. Surface-profile and movement-path of roller are the key factors influencing the thinning ratio of wall thickness of spun workpiece. The influence of surface-profile and movement-path of roller on thickness thinning were studied based on numerical simulation and experimental research, four groups of forming experiments were carried out under the combination of the different surface-profile of roller (R12 and R25-12 and movement-path of roller (spinning from the bottom of the blank and spinning from the middle of the blank. The results show that both the surface-profile and movement-path of roller have great influence on wall thickness thinning during multi-pass deep drawing spinning; and compared with the movement-path of roller, the influence of surface-profile of roller is more significant. The experimental results conform well to the simulation ones. It indicates that the FEA model established is reasonable and reliable.

Oriented Onion Sowing by a Forked-Roller Sowing Unit

Directory of Open Access Journals (Sweden)

Aleksandr G.

2018-03-01

Full Text Available Introduction: The existing sowing machines do not provide a single feeding of the bulbs with a planting (sowing unit that leads to a violation of the agrotechnical requirements of planting bulbs. It is necessary to search new solutions to preserve the position of the bulbs in the furrow with the bottom down and their regularly spaced distribution. Materials and Methods: The article presents the design for a prototype for a planting machine equipped with a forked-roller sowing unit for orienting the onion-sowing into a furrow. Testing the forked-roller sowing unit were carried out on a flat area where the physical and mechanical properties of the soil were determined on the days of sowing, and the indices of the quality of the onion-sowing were determined. The study of the effect of the sowing machine speed on the quality of the onion-seed bulb landing was determined by the change in the translational speed of the sowing unit in the range of 0.8 m/s to 1.2 m/s with a variation interval of 0.1 m/s. The indicators of the quality of the planting of the bulbs were determined by the opening of the closed furrow. The results of laboratory-field studies of the planting machine prototype are presented. Results: The results of laboratory-field studies of a planting machine equipped with a forked-roller sowing unit for planting onion bulbs are presented. The optimal technological parameters are determined experimentally. It was determined the number of bulbs that are for up is 51 % and the regularity of planting by the forked-roller sowing unit – 79 %. These figures are provided at the forward speed of the planting machine VM = 0.9–1.0 m/s, the height of the fall of the bulb HA = 0.12 m, and the rotation frequency of the landing drum nБ = 0.47 c-1. Discussion and Conclusions: The use of a forked-roller sowing unit makes it possible to increase the proportion of onions planted by bottom down by 200 %, and the uniformity of planting bulbs by 19 %, in

Helicopter electromagnetic and magnetic geophysical survey data, Hunton anticline, south-central Oklahoma

Science.gov (United States)

Smith, Bruce D.; Smith, David V.; Deszcz-Pan, Maryla; Blome, Charles D.; Hill, Patricia

2011-01-01

This report is a digital data release for multiple geophysical surveys conducted in the Hunton anticline area of south-central Oklahoma. The helicopter electromagnetic and magnetic surveys were flown on March 16–17, 2007, in four areas of the Hunton anticline in south-central Oklahoma. The objective of this project is to improve the understanding of the geohydrologic framework of the Arbuckle-Simpson aquifer. The electromagnetic sensor for the helicopter electromagnetic survey consisted of six different transmitter-receiver orientations that measured the earth's electrical response at six distinct frequencies from approximately 500 Hertz to approximately 115,000 Hertz. The electromagnetic measurements were converted to electrical resistivity values, which were gridded and plotted on georeferenced maps. The map from each frequency represents a different depth of investigation for each area. The range of subsurface investigation is comparable to the depth of shallow groundwater. The four areas selected for the helicopter electromagnetic study, blocks A–D, have different geologic and hydrologic settings. Geophysical and hydrologic information from U.S. Geological Survey studies are being used by modelers and resource managers to develop groundwater resource plans for the Arbuckle-Simpson aquifer.

Improvement of Roller Bearing Diagnosis with Unlabeled Data Using Cut Edge Weight Confidence Based Tritraining

Directory of Open Access Journals (Sweden)

Wei-Li Qin

2016-01-01

Full Text Available Roller bearings are one of the most commonly used components in rotational machines. The fault diagnosis of roller bearings thus plays an important role in ensuring the safe functioning of the mechanical systems. However, in most cases of bearing fault diagnosis, there are limited number of labeled data to achieve a proper fault diagnosis. Therefore, exploiting unlabeled data plus few labeled data, this paper proposed a roller bearing fault diagnosis method based on tritraining to improve roller bearing diagnosis performance. To overcome the noise brought by wrong labeling into the classifiers training process, the cut edge weight confidence is introduced into the diagnosis framework. Besides a small trick called suspect principle is adopted to avoid overfitting problem. The proposed method is validated in two independent roller bearing fault experiment vibrational signals that both include three types of faults: inner-ring fault, outer-ring fault, and rolling element fault. The results demonstrate the desirable diagnostic performance improvement by the proposed method in the extreme situation where there is only limited number of labeled data.

Verkkokaupan kansainvälistäminen Facebook-mainonnalla : Case HighRoller

OpenAIRE

Heikkinen, Tiia

2016-01-01

Verkkokauppa toimii HighRoller Suomi Oy:n HighRoller-lihashuoltolaiteen pääasiallisena myyntikanavana ja Facebook-markkinointikanavana. Tähän mennessä tuotetta on markkinoitu Facebookissa ilman varsinaista strategiaa. Nyt tuotetta viedään Ruotsiin ja uusia markkinoita varten suunniteltiin ja toteutettiin Facebook-mainoskampanja. Teoreettisessä viitekehyksessä käydään läpi aluksi digimarkkinointia, minkä jälkeen pohditaan sosiaalisen median merkitystä verkkokaupalle. Seuraavaksi keskitytää...

Mechanical Design of Metal Dome for Industrial Application

Science.gov (United States)

Jin-Chee Liu, Thomas; Chen, Li-Wei; Lin, Nai-Pin

2018-02-01

In this paper, the mechanical design of metal domes is studied using finite element analysis. The snap-through behavior of a practical button design that uses a metal dome is found. In addition, the individual click ratio and maximum force for a variety of metal domes are determined. This paper provides guidance on button design for industrial engineers.

Autonomous Dome for a Robotic Telescope

Science.gov (United States)

Kumar, A.; Sengupta, A.; Ganesh, S.

2016-12-01

The Physical Research Laboratory operates a 50 cm robotic observatory at Mount Abu (Rajsthan, India). This Automated Telescope for Variability Studies (ATVS) makes use of the Remote Telescope System 2 (RTS2) for autonomous operations. The observatory uses a 3.5 m dome from Sirius Observatories. We have developed electronics using Arduino electronic circuit boards with home grown logic and software to control the dome operations. We are in the process of completing the drivers to link our Arduino based dome controller with RTS2. This document is a short description of the various phases of the development and their integration to achieve the required objective.

Geologic study of Kettle dome, northeast Washington. Final report

International Nuclear Information System (INIS)

1980-10-01

This geologic study of Kettle dome, northeast Washington, encompasses an area of approximately 800 square miles (2048 sq km). The evaluation of uranium occurrences associated with the igneous and metamorphic rocks of the dome and the determination of the relationship between uranium mineralization and stratigraphic, structural, and metamorphic features of the dome are the principal objectives. Evaluation of the validity of a gneiss dome model is a specific objective. The principal sources of data are detailed geologic mapping, surface radiometric surveys, and chemical analyses of rock samples. Uranium mineralization is directly related to the presence of pegmatite dikes and sills in biotite gneiss and amphibolite. Other characteristics of the uranium occurrences include the associated migmatization and high-grade metamorphism of wallrock adjacent to the pegmatite and the abrupt decrease in uranium mineralization at the pegmatite-gneiss contact. Subtle chemical characteristics found in mineralized pegmatites include: (1) U increase as K 2 O increases, (2) U decreases as Na 2 O increases, and (3) U increases as CaO increases at CaO values above 3.8%. The concentration of uranium occurrences in biotite gneiss and amphibolite units results from the preferential intrusion of pegmitites into these well-foliated rocks. Structural zones of weakness along dome margins permit intrusive and migmatitic activity to affect higher structural levels of the dome complex. As a result, uranium mineralization is localized along dome margins. The uranium occurrences in the Kettle dome area are classified as pegmatitic. Sufficient geologic similarities exist between Kettle dome and the Rossing uranium deposit to propose the existence of economic uranium targets within Kettle dome

An investigation into the impact of magnesium stearate on powder feeding during roller compaction.

Science.gov (United States)

Dawes, Jason; Gamble, John F; Greenwood, Richard; Robbins, Phil; Tobyn, Mike

2012-01-01

A systematic evaluation on the effect of magnesium stearate on the transmission of a placebo formulation from the hopper to the rolls during screw fed roller compaction has been carried out. It is demonstrated that, for a system with two 'knurled' rollers, addition of 0.5% w/w magnesium stearate can lead to a significant increase in ribbon mass throughput, with a consequential increase in roll gap, compared to an unlubricated formulation (manufactured at equivalent process conditions). However, this effect is reduced if one of the rollers is smooth. Roller compaction of a lubricated formulation using two smooth rollers was found to be ineffective due to a reduction in friction at the powder/roll interface, i.e. powder was not drawn through the rollers leading to a blockage in the feeding system. An increase in ribbon mass throughput could also be achieved if the equipment surfaces were pre-lubricated. However this increase was found to be temporary suggesting that the residual magnesium stearate layer was removed from the equipment surfaces. Powder sticking to the equipment surfaces, which is common during pharmaceutical manufacturing, was prevented if magnesium stearate was present either in the blend, or at the roll surface. It is further demonstrated that the influence of the hopper stirrer, which is primarily used to prevent bridge formation in the hopper and help draw powder more evenly into the auger chamber, can lead to further mixing of the formulation, and could therefore affect a change in the lubricity of the carefully blended input material.

Design rules for out-of-plane stability of roller bent steel arches with FEM

NARCIS (Netherlands)

Spoorenberg, R.C.; Snijder, H.H.; Hoenderkamp, J.C.D.; Beg, D.

2012-01-01

This paper describes a numerical investigation into the out-of-plane buckling behavior of freestanding roller bent steel arches. As roller bent arches have structural imperfections which differ considerably from those of hot-rolled or welded sections, specific attention is paid to their inclusion in

Himalayan gneiss dome formation in the middle crust and exhumation by normal faulting: New geochronology of Gianbul dome, northwestern India

Science.gov (United States)

Horton, Forrest; Lee, Jeffrey; Hacker, Bradley; Bowman-Kamaha'o, Meilani; Cosca, Michael A.

2015-01-01

A general lack of consensus about the origin of Himalayan gneiss domes hinders accurate thermomechanical modeling of the orogen. To test whether doming resulted from tectonic contraction (e.g., thrust duplex formation, antiformal bending above a thrust ramp, etc.), channel flow, or via the buoyant rise of anatectic melts, this study investigates the depth and timing of doming processes for Gianbul dome in the western Himalaya. The dome is composed of Greater Himalayan Sequence migmatite, Paleozoic orthogneiss, and metasedimentary rock cut by multiple generations of leucogranite dikes. These rocks record a major penetrative D2 deformational event characterized by a domed foliation and associated NE-SW–trending stretching lineation, and they are flanked by the top-down-to-the-SW (normal-sense) Khanjar shear zone and the top-down-to-the-NE (normal sense) Zanskar shear zone (the western equivalent of the South Tibetan detachment system). Monazite U/Th-Pb geochronology records (1) Paleozoic emplacement of the Kade orthogneiss and associated granite dikes; (2) prograde Barrovian metamorphism from 37 to 33 Ma; (3) doming driven by upper-crustal extension and positive buoyancy of decompression melts between 26 and 22 Ma; and (4) the injection of anatectic melts into the upper levels of the dome—neutralizing the effects of melt buoyancy and potentially adding strength to the host rock—by ca. 22.6 Ma on the southwestern flank and ca. 21 Ma on the northeastern flank. As shown by a northeastward decrease in 40Ar/39Ar muscovite dates from 22.4 to 20.2 Ma, ductile normal-sense displacement within the Zanskar shear zone ended by ca. 22 Ma, after which the Gianbul dome was exhumed as part of a rigid footwall block below the brittle Zanskar normal fault, tilting an estimated 5°–10°SW into its present orientation.

A Growing Anticline in Tainan City, Taiwan

Science.gov (United States)

Lee, C.; Lee, C.; Cheng, C.; Liao, C.; Wen, S.

2001-12-01

Tainan City has been known as an earthquake prone town since the early immigration of the ¡§Han¡" people from Mainland China about four hundred years ago. For the purpose of clarifying tectonic activity and paleo-earthquakes in the Tainan City area, we have finished the excavation of three trenches and the drilling of four holes at the so-called Houchiali Fault on the eastern margin of the Tainan tableland. We carefully observed the cores and exposures in the trenches, performed a detailed mapping, and took samples for C-14 dating and other types of analysis. The results show the trench sites are located at a flexure scarp without direct evidence of faulting. But, from the fact of tilting of Holocene sediments to about 50 degrees and the development of a fracture system in the sediments, one may realize that this is without doubt an active structure. We have tested many different models to interpret the observed geologic evidence in the trenches and outcrops, finally determined a growing fault-propagation fold model to be the best interpretation for the Tainan Anticline, while the Houchiali fault is a back-kink or a blind back-thrust type. A diapiric fold had been discussed as possible for a long time by many researchers, but a fault-propagation fold in origin does not contradict with a mud diapiric feature, which was formed during the folding. Field evidence shows that the main active phase of the Houchiali Fault and the Tainan Anticline would have been after the deposition of the Tainan Formation about two to three thousand years ago. During the active deformation phase, the Tawan Formation onlaped the Tainan Formation, as well as tilted during the folding, thus, beds on higher stratigraphic horizon show lower dip-angle. Estimated from a detailed geologic profile, the horizontal shortening of the anticline is estimated to be 30 meters. The vertical uplift of the Tainan Formation is also about 30 meters. This indicates that the deformation rate has been about 1

The Discovery Dome: A Tool for Increasing Student Engagement

Science.gov (United States)

Brevik, Corinne

2015-04-01

The Discovery Dome is a portable full-dome theater that plays professionally-created science films. Developed by the Houston Museum of Natural Science and Rice University, this inflatable planetarium offers a state-of-the-art visual learning experience that can address many different fields of science for any grade level. It surrounds students with roaring dinosaurs, fascinating planets, and explosive storms - all immersive, engaging, and realistic. Dickinson State University has chosen to utilize its Discovery Dome to address Earth Science education at two levels. University courses across the science disciplines can use the Discovery Dome as part of their curriculum. The digital shows immerse the students in various topics ranging from astronomy to geology to weather and climate. The dome has proven to be a valuable tool for introducing new material to students as well as for reinforcing concepts previously covered in lectures or laboratory settings. The Discovery Dome also serves as an amazing science public-outreach tool. University students are trained to run the dome, and they travel with it to schools and libraries around the region. During the 2013-14 school year, our Discovery Dome visited over 30 locations. Many of the schools visited are in rural settings which offer students few opportunities to experience state-of-the-art science technology. The school kids are extremely excited when the Discovery Dome visits their community, and they will talk about the experience for many weeks. Traveling with the dome is also very valuable for the university students who get involved in the program. They become very familiar with the science content, and they gain experience working with teachers as well as the general public. They get to share their love of science, and they get to help inspire a new generation of scientists.

Identifying suitable piercement salt domes for nuclear waste storage sites

International Nuclear Information System (INIS)

Kehle, R.; e.

1980-08-01

Piercement salt domes of the northern interior salt basins of the Gulf of Mexico are being considered as permanent storage sites for both nuclear and chemically toxic wastes. The suitable domes are stable and inactive, having reached their final evolutionary configuration at least 30 million years ago. They are buried to depths far below the level to which erosion will penetrate during the prescribed storage period and are not subject to possible future reactivation. The salt cores of these domes are themselves impermeable, permitting neither the entry nor exit of ground water or other unwanted materials. In part, a stable dome may be recognized by its present geometric configuration, but conclusive proof depends on establishing its evolutionary state. The evolutionary state of a dome is obtained by reconstructing the growth history of the dome as revealed by the configuration of sedimentary strata in a large area (commonly 3,000 square miles or more) surrounding the dome. A high quality, multifold CDP reflection seismic profile across a candidate dome will provide much of the necessary information when integrated with available subsurface control. Additional seismic profiles may be required to confirm an apparent configuration of the surrounding strata and an interpreted evolutionary history. High frequency seismic data collected in the near vicinity of a dome are also needed as a supplement to the CDP data to permit accurate depiction of the configuration of shallow strata. Such data must be tied to shallow drill hole control to confirm the geologic age at which dome growth ceased. If it is determined that a dome reached a terminal configuration many millions of years ago, such a dome is incapable of reactivation and thus constitutes a stable storage site for nuclear wastes

Novel hockey-stick mesogens with the nematic, synclinic and anticlinic smectic C phase sequence

Czech Academy of Sciences Publication Activity Database

Novotná, Vladimíra; Žurek, J.; Kozmik, V.; Svoboda, J.; Glogarová, Milada; Kroupa, Jan; Pociecha, D.

2008-01-01

Roč. 35, č. 8 (2008), 1023-1036 ISSN 0267-8292 R&D Projects: GA AV ČR IAA100100710 Institutional research plan: CEZ:AV0Z10100520 Keywords : liquid crystals * synclinic and anticlinic ordering * hockey-stick mezogens Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.132, year: 2008

DomeHaz, a Global Hazards Database: Understanding Cyclic Dome-forming Eruptions, Contributions to Hazard Assessments, and Potential for Future Use and Integration with Existing Cyberinfrastructure

Science.gov (United States)

Ogburn, S. E.; Calder, E.; Loughlin, S.

2013-12-01

Dome-forming eruptions can extend for significant periods of time and can be dangerous; nearly all dome-forming eruptions have been associated with some level of explosive activity. Large Plinian explosions with a VEI ≥ 4 sometimes occur in association with dome-forming eruptions. Many of the most significant volcanic events of recent history are in this category. The 1902-1905 eruption of Mt. Pelée, Martinique; the 1980-1986 eruption of Mount St. Helens, USA; and the 1991 eruption of Mt. Pinatubo, Philippines all demonstrate the destructive power of VEI ≥ 4 dome-forming eruptions. Global historical analysis is a powerful tool for decision-making as well as for scientific discovery. In the absence of monitoring data or a knowledge of a volcano's eruptive history, global analysis can provide a method of understanding what might be expected based on similar eruptions. This study investigates the relationship between large explosive eruptions and lava dome growth and develops DomeHaz, a global database of dome-forming eruptions from 1000 AD to present. It is currently hosted on VHub (https://vhub.org/groups/domedatabase/), a community cyberinfrastructure for sharing data, collaborating, and modeling. DomeHaz contains information about 367 dome-forming episodes, including duration of dome growth, duration of pauses in extrusion, extrusion rates, and the timing and magnitude of associated explosions. Data sources include the The Smithsonian Institution Global Volcanism Program (GVP), Bulletin of the Global Volcanism Network, and all relevant published review papers, research papers, and reports. This database builds upon previous work (e.g Newhall and Melson, 1983) in light of newly available data for lava dome eruptions. There have been 46 new dome-forming eruptions, 13 eruptions that continued past 1982, 151 new dome-growth episodes, and 8 VEI ≥ 4 events since Newhall and Melson's work in 1983. Analysis using DomeHaz provides useful information regarding the

The research of suspen-dome structure

Science.gov (United States)

Gong, Shengyuan

2017-09-01

After overcoming the shortcomings of single-layer latticed shell and cable dome structure, the suspen-dome was developed by inheriting the advantages of them, and it was recognized and applied as a new type of prestressed force large span space structure. Based on the analysis of the background and mechanical principle, the researches of suspen-dome are reviewed, including form-finding analysis, the analysis of static force and stability, the dynamic behaviors and the earthquake resistant behavior, the analysis of prestressing force and optimization design, and the research status of the design of the fir-resistant performance etc. This thesis summarizes the methods of various researches, being a reference for further structural performance research and structural engineering application.

Application research of ferrous matrix composites in roller ring used in high-speed wire/bar rolling mill

International Nuclear Information System (INIS)

Song Yanpei; Li Xiuqing; Bi Shuangxu

2010-01-01

Research highlights: → A composite structure roller rings was fabricated by centrifugal casting. → The roller rings consisted of outer WCP/Fe-C composites layer and inner Fe-C alloy matrix. → Hardness attained to HRA80-85 in the composites layer, and HRA73-76 in inner Fe-C alloy matrix where the toughness was over 8 J/cm 2 . → The wear resistance of the roller rings excelled that of high-speed steel, and approached to that of the WC hard alloy roll. → The production cost of the WCP/Fe-C composites roller ring decreased by 50%. - Abstract: Tungsten carbide particle (WC P ) reinforced ferrous matrix composites roller rings were fabricated by centrifugal casting. The microstructures, properties and application effect of the composites roller rings were investigated by SEM, TEM and various property testers. The experimental results show that the WC P were uniformly distributed in outer reinforced-layer (working-layer) of 20-50 mm in thickness and their volume fraction reached 60-80 vol.%; there was a good interface bonding between WC P and Fe-C alloy without any reaction products; hardness attained to HRA80-85 in working-layer, and HRA73-76 in inner ferrous matrix where the toughness was over 8 J/cm 2 ; the wear resistance of the composites roller rings excels that of high-speed steel; service life of the composites parts approached to that of the WC hard alloy roll when the same WC P -volume-fraction in working-layer were obtained for both of them, but the production cost of the WC P /Fe-C composites roller ring decreased by 50%.

Environmental assessment overview: Richton Dome site, Mississippi

International Nuclear Information System (INIS)

1986-05-01

In February 1983, the US Department of Energy (DOE) identified the Richton Dome site in Mississippi as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Richton Dome site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. The site is in the Gulf interior region, which is one of five distinct geohydrologic settings considered for the first repository. On the basis of the evaluations reported in this EA, the DOE has found that the Richton Dome site is not disqualified under the guidelines. On the basis of these findings, the DOE is nominating the Richton Dome site as one of five sites suitable for characterization. 3 figs

Simple and Versatile Dynamic Model of Spherical Roller Bearing

Directory of Open Access Journals (Sweden)

Behnam Ghalamchi

2013-01-01

Full Text Available Rolling element bearings are essential components of rotating machinery. The spherical roller bearing (SRB is one variant witnessing increasing use because it is self-aligning and can support high loads. It is becoming increasingly important to understand how the SRB responds dynamically under a variety of conditions. This study introduces a computationally efficient, three-degree-of-freedom, SRB model that was developed to predict the transient dynamic behaviors of a rotor-SRB system. In the model, bearing forces and deflections were calculated as a function of contact deformation and bearing geometry parameters according to the nonlinear Hertzian contact theory. The results reveal how some of the more important parameters, such as diametral clearance, the number of rollers, and osculation number, influence ultimate bearing performance. One pair of calculations looked at bearing displacement with respect to time for two separate arrangements of the caged side-by-side roller arrays, when they are aligned and when they are staggered. As theory suggests, significantly lower displacement variations were predicted for the staggered arrangement. Following model verification, a numerical simulation was carried out successfully for a full rotor-bearing system to demonstrate the application of this newly developed SRB model in a typical real world analysis.

Roller pressure algometry as a new tool for assessing dynamic pressure sensitivity in migraine

DEFF Research Database (Denmark)

Guerrero-Peral, Ángel L.; Ruíz, Marina; Barón, Johanna

2018-01-01

from 500 to 5300 g. Each roller was moved at a speed of 0.5 cm/sec over a 60 mm horizontal line covering the temporalis muscle. The dynamic pain threshold (the pressure level of the first painful roller) and pain elicited during the pain threshold (roller evoked pain) were determined. Static pressure...... pain thresholds were assessed over the temporalis muscle, C5/C6 joint, second metacarpal, and tibialis anterior. Results Side-to-side consistency between dynamic pain threshold (rs = 0.769, p ... was slightly stronger in chronic migraine. Pain during dynamic pain threshold was negatively associated with widespread pressure pain thresholds (-0.336 

Effect of Using Porcelanite as Partial Replacement of Fine Aggregate on Roller Compacted Concrete with Different Curing Methods

Directory of Open Access Journals (Sweden)

Abeer Abdulqader Salih

2016-09-01

Full Text Available Roller-Compacted Concrete is a no-slump concrete, with no reinforcing steel, no forms, no finishing and wet enough to support compaction by vibratory rollers. Due to the effect of curing on properties and durability of concrete, the main purpose of this research is to study the effect of various curing methods (air curing, 7 days water curing, and permanent water curing and porcelanite (local material used as an Internal Curing agent with different replacement percentages of fine aggregate (volumetric replacement on some properties of Roller-Compacted Concrete and to explore the possibility of introducing practical Roller-Compacted Concrete for road pavement with minimum requirement of curing. Specimens were sawed from slabs of (380*380*100 mm for determination of Ultrasonic Pulse Velocity (UPV and Voids volume. Results show that using (5 % porcelanite improved the results of UPV and Voids volume of Roller-Compacted Concrete (with air curing as compared with reference Roller-Compacted Concrete (with permanent water curing by percentages ranging from(3.6 to 28.9% and (-8 to -15.5% respectively.

General Case in Determining Center-To-Center Spacing Between the Screw and the Roller in a Roller Drive, and Initial Contact Point of Their Mating Thread Turns. Development of Calculation Method and Software

Directory of Open Access Journals (Sweden)

D. S. Blinov

2017-01-01

Full Text Available One of the most important trends in development of machine engineering is to improve load capacity of mechanisms, assemblies and parts without increasing their overall dimensions and weight. This is also relevant to the most promising items so far, i.e. orbital roller drives (ORD, which are the rotational-to-progressive motion converters widely used in vehicles. The previously published article suggested increasing a load capacity (by about 15% through reducing a thread turn section angle of the threaded ORD components and change of the radius of roller thread turn section outline. Due to such ORD modification, a number of the most critical ORD parameters are to be changed thereby demanding further research. Further, the article published suggests a method considering the abovementioned changes to calculate the dimensions of ORD main components and their tolerance ranges.Though this method being not complete as the increment of ORD center-to-center spacing in relation to its rated value, required for assembly, is unknown; and to determine the ORD center-to-center spacing increment, outer diameters of the roller and screw threads are to be known. Hence, these two methods are interconnected.This article presents the numerical calculation method, mathematical support and method to determine the increment of ORD center-to-center spacing and initial contact point of the mating roller and screw thread turns. Due to considerable scope of calculations, the method was turned into the software.Similar calculation methods and techniques were developed to a particular case, where the thread turn section angle of the threaded components was of 90°, and the roller thread turn section outline was a circular arc centered to the roller axis. Hence the developed numerical calculation method, mathematical support and technique refer to the general case which is to determine the ORD center-to-center spacing increment and initial contact point of the mating roller

Geologic study of the interior Salt Domes of Northeast Texas Salt-Dome basin to investigate their suitability for possible storage of radioactive waste material

International Nuclear Information System (INIS)

1976-05-01

The purpose of this study was to investigate the movement and hydrologic stability of the domes, to identify the domes which appear suitable for further study and consideration, and to outline the additional information needed to evaluate these domes. The growth of the interior salt domes appears to have slowed with geologic time and to have halted altogether. The Bullard, Whitehouse, and Keechi domes probably are not subject to significant dissolution at the present time. However, caprock found at Bullard and Whitehouse indicates that salt dissolution occurred at some period during the past 50 million years since Wilcox was deposited. It is recommended that shallow water wells be drilled and tested

Geological evolution of the Afro-Arabian dome

Science.gov (United States)

Almond, D. C.

1986-12-01

The Afro-Arabian dome includes the elevated continental regions enclosing the Red Sea, Gulf of Aden, and the Ethiopian rift system, and extends northwards as far as Jordan. It is more than an order of magnitude larger than other African uplifts. Both the structures and the igneous rocks of the dome appear to be products of the superimposition of two, perhaps three, semi-independent generating systems, initiated at different times but all still active. A strain pattern dominated by NW-trending basins and rifts first became established early in the Cretaceous. By the end of the Oligocene, much of the extensional strain had been taken up along the Red Sea and Gulf of Aden axes, which subsequently developed into an ocean. Palaeogene "trap" volcanism of mildly alkaline to transitional character was related to this horizontal extension rather than to doming. Further west, the East Sahara swell has a history of intermittent alkaline volcanicity which began in the Mesozoic and was independent of magmatism in the Afro-Arabian dome. Volcanicity specifically related to doming began in the Miocene along a N-S zone of uplift extending from Ethiopia to Syria. This elongated swell forms the northern termination of the East African system of domes and rifts, characterized by episodic vertical uplift but very little extension. Superimposition of epeirogenic uplift upon structures formed by horizontal extension took place in the Neogene. Volcanicity related to vertical tectonics is mildly alkaline in character, whereas transitional and tholeiitic magmas are found along the spreading axes.

Biomechanical pole and leg characteristics during uphill diagonal roller skiing.

Science.gov (United States)

Lindinger, Stefan Josef; Göpfert, Caroline; Stöggl, Thomas; Müller, Erich; Holmberg, Hans-Christer

2009-11-01

Diagonal skiing as a major classical technique has hardly been investigated over the last two decades, although technique and racing velocities have developed substantially. The aims of the present study were to 1) analyse pole and leg kinetics and kinematics during submaximal uphill diagonal roller skiing and 2) identify biomechanical factors related to performance. Twelve elite skiers performed a time to exhaustion (performance) test on a treadmill. Joint kinematics and pole/plantar forces were recorded separately during diagonal roller skiing (9 degrees; 11 km/h). Performance was correlated to cycle length (r = 0.77; P Push-off demonstrated performance correlations for impulse of leg force (r = 0.84), relative duration (r= -0.76) and knee flexion (r = 0.73) and extension ROM (r = 0.74). Relative time to peak pole force was associated with performance (r = 0.73). In summary, diagonal roller skiing performance was linked to 1) longer cycle length, 2) greater impulse of force during a shorter push-off with larger flexion/extension ROMs in leg joints, 3) longer leg swing, and 4) later peak pole force, demonstrating the major key characteristics to be emphasised in training.

Kinematics and Path Following Control of an Articulated Drum Roller

Science.gov (United States)

BIAN, Yongming; YANG, Meng; FANG, Xiaojun; WANG, Xiahui

2017-07-01

Automatic navigation of an articulated drum roller, which is an articulated steering type vehicle widely used in the construction industry, is highly expected for operation cost reduction and improvement of work efficiency. In order to achieve the path following control, considering that its steering system is articulated steering and two frames are articulated by an active revolute joint, a kinematic model and an error dynamic state-space equation of an articulated drum roller are proposed. Besides, a state-feedback control law based on Lyapunov stability theory is also designed, which can be proved to achieve the purpose of control by the analysis of stability. What's more, to evaluate the performance of the proposed method, simulation under the MATLAB/Simulink and experiments using positioning algorithm and errors correction at the uneven construction site are performed, with initial displacement error (-1.5 m), heading error (-0.11 rad) and steering angle (-0.19 rad). Finally, simulation and experimental results show that the errors and steering angle can decrease gradually, and converge to zero with time. Meanwhile, the control input is not saturated. An articulated drum roller can lock into a desired path with the proposed method in uneven fields.

Geology--hydrology of Avery Island Salt Dome

International Nuclear Information System (INIS)

Jacoby, C.H.

1977-07-01

After a review of the geology of the Gulf Coast salt domes, the geology (geomorphology and tectonics) and hydrology of Avery Island Dome, 10 miles south-southwest of New Iberia, Louisiana, were studied in detail. Rock mechanics were studied using grouts and piezometers. 17 figs

77 FR 50716 - Tapered Roller Bearings From China

Science.gov (United States)

2012-08-22

... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-344 (Third Review)] Tapered Roller..., the United States International Trade Commission (Commission) determines, pursuant to section 751(c... notice in the Office of the Secretary, U.S. International Trade Commission, Washington, DC, and by...

Shapes of Venusian 'pancake' domes imply episodic emplacement and silicic composition

Science.gov (United States)

Fink, Jonathan H.; Bridges, Nathan T.; Grimm, Robert E.

1993-01-01

The main evidence available for constraining the composition of the large circular 'pancake' domes on Venus is their gross morphology. Laboratory simulations using polyethylene glycol show that the height to diameter (aspect) ratios of domes of a given total volume depend critically on whether their extrusion was continuous or episodic, with more episodes leading to greater cooling and taller domes. Thus without observations of their emplacement, the compositions of Venusian domes cannot be uniquely constrained by their morphology. However, by considering a population of 51 Venusian domes to represent a sampling of many stages during the growth of domes with comparable histories, and by plotting aspect ratio versus total volume, we find that the shapes of the domes are most consistent with episodic emplacement. On Earth this mode of dome growth is found almost exclusively in lavas of dacite to rhyolite composition, strengthening earlier inferences about the presence of evolved magmas on Venus.

A Roller Bearing Fault Diagnosis Method Based on LCD Energy Entropy and ACROA-SVM

Directory of Open Access Journals (Sweden)

HungLinh Ao

2014-01-01

Full Text Available This study investigates a novel method for roller bearing fault diagnosis based on local characteristic-scale decomposition (LCD energy entropy, together with a support vector machine designed using an Artificial Chemical Reaction Optimisation Algorithm, referred to as an ACROA-SVM. First, the original acceleration vibration signals are decomposed into intrinsic scale components (ISCs. Second, the concept of LCD energy entropy is introduced. Third, the energy features extracted from a number of ISCs that contain the most dominant fault information serve as input vectors for the support vector machine classifier. Finally, the ACROA-SVM classifier is proposed to recognize the faulty roller bearing pattern. The analysis of roller bearing signals with inner-race and outer-race faults shows that the diagnostic approach based on the ACROA-SVM and using LCD to extract the energy levels of the various frequency bands as features can identify roller bearing fault patterns accurately and effectively. The proposed method is superior to approaches based on Empirical Mode Decomposition method and requires less time.

Borehole locations on seven interior salt domes

International Nuclear Information System (INIS)

Simcox, A.C.; Wampler, S.L.

1982-08-01

This report is designed as an inventory of all wells known to have been drilled within a five-mile radius of each of seven salt domes within the Interior Salt Basin in east Texas, northern Louisiana and Mississippi. There are 72 boreholes that entered salt above an elevation of -3000 feet mean sea level. For these, details of location, drilling dates, depth of casing and cement, elevation of top of caprock and salt, etc., are given on tables in the appendix. Of the seven domes, Oakwood has the largest number of boreholes, thirty-eight (including two sidetracked wells) that enter the salt stock above -3000 feet mean sea level; another dome in northeast Texas, Keechi, has eight; in northern Louisiana, Rayburn's has four and Vacherie has five; in southern Mississippi, Cypress Creek has seven, Lampton has one, and Richton has nine. In addition, all wells known outside the supra-domal area, but within a five-mile radius of the center of the 7 domes are separately catalogued

Simulation and Analysis of Roller Chain Drive Systems

DEFF Research Database (Denmark)

Pedersen, Sine Leergaard

The subject of this thesis is simulation and analysis of large roller chain drive systems, such as e.g. used in marine diesel engines. The aim of developing a chain drive simulation program is to analyse dynamic phenomena of chain drive systems and investigate different design changes to the syst......The subject of this thesis is simulation and analysis of large roller chain drive systems, such as e.g. used in marine diesel engines. The aim of developing a chain drive simulation program is to analyse dynamic phenomena of chain drive systems and investigate different design changes...... mathematical models, and compare to the prior done research. Even though the model is developed at first for the use of analysing chain drive systems in marine engines, the methods can with small changes be used in general, as for e.g. chain drives in industrial machines, car engines and motorbikes. A novel...

A method of increasing the depth of the plastically deformed layer in the roller burnishing process

Science.gov (United States)

Kowalik, Marek; Trzepiecinski, Tomasz

2018-05-01

The subject of this paper is an analysis of the determination of the depth of the plastically deformed layer in the process of roller burnishing a shaft using a newly developed method in which a braking moment is applied to the roller. It is possible to increase the depth of the plastically deformed layer by applying the braking moment to the roller during the burnishing process. The theoretical considerations presented are based on the Hertz-Bielayev and Huber-Mises theories and permit the calculation of the depth of plastic deformation of the top layer of the burnished shaft. The theoretical analysis has been verified experimentally and using numerical calculations based on the finite element method using the Msc.MARC program. Experimental tests were carried out on ring-shaped samples made of C45 carbon steel. The samples were burnished at different values of roller force and different values of braking moment. A significant increase was found in the depth of the plastically deformed surface layer of roller burnished shafts. Usage of the phenomenon of strain hardening of steel allows the technology presented here to increase the fatigue life of the shafts.

Assessment of solid microneedle rollers to enhance transmembrane delivery of doxycycline and inhibition of MMP activity.

Science.gov (United States)

Omolu, Abbie; Bailly, Maryse; Day, Richard M

2017-11-01

Many chronic wounds exhibit high matrix metalloproteinase (MMP) activity that impedes the normal wound healing process. Intradermal delivery (IDD) of sub-antimicrobial concentrations of doxycycline, as an MMP inhibitor, could target early stages of chronic wound development and inhibit further wound progression. To deliver doxycycline intradermally, the skin barrier must be disrupted. Microneedle rollers offer a minimally invasive technique to penetrate the skin by creating multiple microchannels that act as temporary conduits for drugs to diffuse through. In this study, an innovative and facile approach for delivery of doxycycline across Strat-M TM membrane was investigated using microneedle rollers. The quantity and rate of doxycycline diffusing through the micropores directly correlated with increasing microneedle lengths (250, 500 and 750 μm). Treatment of Strat-M TM with microneedle rollers resulted in a reduction in fibroblast-mediated collagen gel contraction and MMP activity compared with untreated Strat-M TM . Our results show that treatment of an epidermal mimetic with microneedle rollers provides sufficient permeabilization for doxycycline diffusion and inhibition of MMP activity. We conclude that microneedle rollers are a promising, clinically ready tool suitable for delivery of doxycycline intradermally to treat chronic wounds.

High-resolution seismic reflection study, Vacherie Dome

International Nuclear Information System (INIS)

1984-06-01

A high-resolution seismic reflection study, consisting of recording, processing, and interpreting four seismic reflection lines, was made at Vacherie Dome, Louisiana. The presumed shape of the dome, as pictured in the geologic area characterization report by Law Engineering Testing Company in 1982, was based largely on interpretation of gravity data, constrained by a few wells and exploration-type seismic profiles. The purpose of the study was to obtain refined profiles of the dome above -914 m (-3000 ft) elevation. Additional study had been recommended by Louisiana State University in 1967 and the Office of Nuclear Waste Isolation in 1981 because the interpreted size of Vacherie Dome was based on limited seismic and gravity data. Forty-eight traces of seismic data were recorded each time shots were made to generate energy. Twelve-fold, common-depth-point data were obtained using geophone stations spaced at 15-m (50-ft) intervals with shots at 30-m (100-ft) intervals. The time-sampling interval used was 1 ms. Processing intended to enhance resolution included iterative static corrections, deconvolution before stacking, and both time- and depth-migration. The locations of the steep dome sides were inferred primarily from terminations of strong reflections (migrated) from strata near the top of the upper and lower Cretaceous sections. This interpretation agrees closely with the presumed shape from the top of the dome to about -610 m (-2000 ft) elevation, but below this on three of the profiles, this interpretation indicates a steeper salt face than the presumed shape. The area reduction at -914 m (-3000 ft) elevation is estimated to be on the order of 20 percent. 10 references, 11 figures, 4 tables

Roller-massager application to the quadriceps and knee-joint range of motion and neuromuscular efficiency during a lunge.

Science.gov (United States)

Bradbury-Squires, David J; Noftall, Jennifer C; Sullivan, Kathleen M; Behm, David G; Power, Kevin E; Button, Duane C

2015-02-01

Roller massagers are used as a recovery and rehabilitative tool to initiate muscle relaxation and improve range of motion (ROM) and muscular performance. However, research demonstrating such effects is lacking. To determine the effects of applying a roller massager for 20 and 60 seconds on knee-joint ROM and dynamic muscular performance. Randomized controlled clinical trial. University laboratory. Ten recreationally active men (age = 26.6 ± 5.2 years, height = 175.3 ± 4.3 cm, mass = 84.4 ± 8.8 kg). Participants performed 3 randomized experimental conditions separated by 24 to 48 hours. In condition 1 (5 repetitions of 20 seconds) and condition 2 (5 repetitions of 60 seconds), they applied a roller massager to the quadriceps muscles. Condition 3 served as a control condition in which participants sat quietly. Visual analog pain scale, electromyography (EMG) of the vastus lateralis (VL) and biceps femoris during roller massage and lunge, and knee-joint ROM. We found no differences in pain between the 20-second and 60-second roller-massager conditions. During 60 seconds of roller massage, pain was 13.5% (5.7 ± 0.70) and 20.6% (6.2 ± 0.70) greater at 40 seconds and 60 seconds, respectively, than at 20 seconds (P joint ROM was 10% and 16% greater in the 20-second and 60-second roller-massager conditions, respectively, than the control condition (P joint ROM and neuromuscular efficiency during a lunge.

Simulation of accelerated strip cooling on the hot rolling mill run-out roller table

International Nuclear Information System (INIS)

Muhin, U.; Belskij, S.; Makarov, E.; Koinov, T.

2013-01-01

Full text: A mathematical model of the thermal state of the metal on the run-out roller table of a continuous wide hot-strip mill is presented. The mathematical model takes into account the heat generation during the polymorphic γ → α transformation of super cooled austenite phase and the influence of chemical composition on the physical properties of the steel. The model allows the calculation of modes of accelerated cooling of strips on the run-out roller table of a continuous wide hot strip mill. Winding temperature calculation error does not exceed 20 °C for 98.5 % of the strips from low-carbon and low-alloyed steels. key words: hot rolled, wide-strip, accelerated cooling, run-out roller table, polymorphic transformation, mathematical modeling

Increasing the Energy Efficiency of the Cyclic Action Mechanisms in Rolling for a Roller Bed Used as an Example

Science.gov (United States)

andreev, A. N.; Kolesnichenko, D. A.

2017-12-01

The possibility of increasing the energy efficiency of the production cycle in a roller bed is briefly reviewed and justified. The sequence diagram of operation of the electrical drive in a roller bed is analyzed, and the possible increase in the energy efficiency is calculated. A method for energy saving is described for the application of a frequency-controlled asynchronous electrical drive of drive rollers in a roller bed with an increased capacitor capacity in a dc link. A fine mathematical model is developed to describe the behavior of the electrical drive during the deceleration of a roller bed. An experimental setup is created and computer simulation and physical modeling are performed. The basic information flows of the general hierarchical automatic control system of an enterprise are described and determined with allowance for the proposed method of increasing the energy efficiency.

Do Maximal Roller Skiing Speed and Double Poling Performance Predict Youth Cross-Country Skiing Performance?

Directory of Open Access Journals (Sweden)

Roland Stöggl, Erich Müller, Thomas Stöggl

2017-09-01

Full Text Available The aims of the current study were to analyze whether specific roller skiing tests and cycle length are determinants of youth cross-country (XC skiing performance, and to evaluate sex specific differences by applying non-invasive diagnostics. Forty-nine young XC skiers (33 boys; 13.8 ± 0.6 yrs and 16 girls; 13.4 ± 0.9 yrs performed roller skiing tests consisting of both shorter (50 m and longer durations (575 m. Test results were correlated with on snow XC skiing performance (PXC based on 3 skating and 3 classical distance competitions (3 to 6 km. The main findings of the current study were: 1 Anthropometrics and maturity status were related to boys’, but not to girls’ PXC; 2 Significant moderate to acceptable correlations between girls’ and boys’ short duration maximal roller skiing speed (double poling, V2 skating, leg skating and PXC were found; 3 Boys’ PXC was best predicted by double poling test performance on flat and uphill, while girls’ performance was mainly predicted by uphill double poling test performance; 4 When controlling for maturity offset, boys’ PXC was still highly associated with the roller skiing tests. The use of simple non-invasive roller skiing tests for determination of PXC represents practicable support for ski clubs, schools or skiing federations in the guidance and evaluation of young talent.

Susceptibility of lava domes to erosion and collapse by toppling on cooling joints

Science.gov (United States)

Smith, John V.

2018-01-01

The shape of lava domes typically leads to the formation of radial patterns of cooling joints. These cooling joints define the orientation of the columnar blocks which plunge toward the center of the dome. In the lower parts of the dome the columns plunge into the dome at low angles and are relatively stable. Higher in the dome the columns plunge into the dome at steep angles. These steeply plunging columns are susceptible to toppling and, if the lower part of a dome is partially removed by erosion or collapse, the unstable part of the dome becomes exposed leading to toppling failure. Examples of this process are provided from coastal erosion of lava domes at Katsura Island, Shimane Peninsula, western Japan. An analogue model is presented to demonstrate the mechanism. It is proposed that the mechanism can contribute to collapse of lava domes during or after emplacement.

Mechanical analysis and optimisation of large and highly-loaded bearing rollers For the "Riesenrad" Ion Gantry

CERN Document Server

Reimoser, S A

2000-01-01

A carbon ion gantry would allow the irradiation of cancer patients with carbon ions from any direction in space best suited for therapy. Till today, such a machine has not been built due to the expected size, mass and cost. A novel design, called "Riesenrad" ion gantry, promises to provide a competitive solution. The central part of the Riesenrad, which can rotate ± 90°, is supported (statically determinate) on pendular bearing units with two rollers each. High precision requirements for the structure rule out any plastic deformations in the area of contact. The present report describes the design of the highly-loaded rollers. In order to achieve a large contact area and a uniform distribution of contact stresses, a "barrel shape" for the rollers is proposed. An analysis using the finite element method (FEM) was performed to optimise the roller design, namely to establish the required crown roll (camber radius).

Topical reports on Louisiana salt domes

International Nuclear Information System (INIS)

1983-09-01

The Institute for Environmental Studies at Louisiana State University conducted research into the potential use of Louisiana salt domes for disposal of nuclear waste material. Topical reports generated in 1981 and 1982 related to Vacherie and Rayburn's domes are compiled and presented, which address palynological studies, tiltmeter monitoring, precise releveling, saline springs, and surface hydrology. The latter two are basically a compilation of references related to these topics. Individual reports are abstracted

Gut-associated Lymphoid Tissue (GALT) Carcinoma or Dome Carcinoma?

Science.gov (United States)

Rubio, Carlos A; Schmidt, Peter T

2016-10-01

The vast majority of colorectal carcinomas (CRCs) evolve from mucosa not associated to lymphoid tissues aggregates via the adenoma-carcinoma sequence or via the serrated pathway. Rarely CRCs evolve from gut mucosa associated to lymphoid tissue (GALT). Based on the presence of a circumscribed elevation in the colorectal mucosa, GALT carcinomas are also referred to as dome carcinomas (DC). Descriptions of the surface mucosa covering 21 GALT-CRCs appearing in pathological reports were reviewed. Three of the 21 GALT-CRCs fulfilled the criteria of dome carcinoma. Of the remaining 18 GALT-CRCs, nine were described as polypoid lesions, five as plaque-like lesions, two as sessile elevated lesions or mass, one as ulcerated and one as histological finding. Hence, only 14.3% (n=3) of the 21 GALT-CRCs displayed a dome configuration, whereas the majority, 85.7% (n=18), exhibited structures other than dome shapes at gross or at histologic examination. It becomes apparent that by using "dome" in addressing carcinomas in the colorectal mucosa, many cases of GALT carcinomas might be overlooked. Another drawback of using the "dome" nomenclature is that dome-like outlines may be detected in small metastatic tumors in the submucosa or in small colorectal carcinomas not arising from GALT mucosa. Instead, by using "GALT carcinoma", that is the histologic diagnosis in addressing these neoplasias, all cases of GALT-CRCs will be included. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

The use of aluminum dome tank roofs

International Nuclear Information System (INIS)

Morovich, G.L.

1992-01-01

Since the late 1970's the aluminum dome tank roof has gained wide usage for both new and retrofit applications. The increased application for the structure results from a need for maintenance reduction, environmental considerations, concern for product quality and economics. The American Petroleum Institute (API) has approved Standard API 650, Appendix G - Structurally Supported Aluminum Dome Roofs for publication. The aluminum dome was originally used as weather cover for retrofiting external floating roof tanks. The roof was considered for the reduction of maintenance related to draining water from the external floating roofs and problems resulting from freezing of drain lines and snow accumulation. This paper reports that environmental concerns have expanded the value of aluminum dome roofs. Rainwater bypassing the seals of an external floating roof became classified as a hazardous material requiring special and expensive disposal procedures. The marketing terminal facilities typically do not have the capacity for proper treatment of contaminated bottom water. With new fuel additives being water soluble, water contamination not only created a hazardous waste disposal problem, but resulted in reduced product quality

The compression dome concept: the restorative implications.

Science.gov (United States)

Milicich, Graeme

2017-01-01

Evidence now supports the concept that the enamel on a tooth acts like a compression dome, much like the dome of a cathedral. With an overlying enamel compression dome, the underlying dentin is protected from damaging tensile forces. Disruption of a compression system leads to significant shifts in load pathways. The clinical restorative implications are significant and far-reaching. Cutting the wrong areas of a tooth exposes the underlying dentin to tensile forces that exceed natural design parameters. These forces lead to crack propagation, causing flexural pain and eventual fracture and loss of tooth structure. Improved understanding of the microanatomy of tooth structure and where it is safe to cut teeth has led to a revolution in dentistry that is known by several names, including microdentistry, minimally invasive dentistry, biomimetic dentistry, and bioemulation dentistry. These treatment concepts have developed due to a coalescence of principles of tooth microanatomy, material science, adhesive dentistry, and reinforcing techniques that, when applied together, will allow dentists to repair a compromised compression dome so that it more closely replicates the structure of the healthy tooth.

Analytical evaluation of the roller bearing service life

Directory of Open Access Journals (Sweden)

Antsupov Aleksey

2017-01-01

Full Text Available An analytical method has been developed for the design evaluation of the service life of roller bearings by the criterion of contact endurance of elements that does not require carrying out the experimental studies. It is based on the kinetic approach to the description of the solids destruction process and the theory of parametric reliability of machine parts. In contradistinction to the standard empirical dependence, which is currently used, the method allows one to take into account the effect of the material properties, and basic design and operational parameters on the service life. The results of the theoretical studies of the service life of roller bearing No. 212 (DIN 5412 T1 are presented for the quantitative assessment of this effect. They showed that the temperature-force loading conditions or material properties that were not taken into account might result in the prediction error of 1.5 or more times.

Status of Gulf Coast salt dome characterization

International Nuclear Information System (INIS)

Swanson, O.E.; Gibbons, M.G.; Deyling, M.A.; McPherson, R.B.

1982-01-01

Screening and characterization for a potential nuclear waste repository have progressed through the area phase in these Gulf Coast Salt Basins. The domes studied during the area phase are described briefly. The area characterization studies are outlined, and the resulting reports are listed. Geologic and environmental studies resulted in elimination of four domes from further consideration. The remaining domes were judged acceptable and were classified as to their favorability to license. Site characterization planning for location phase activities deals primarily with technical, environmental, and socioeconomic issues of concern to the states and/or to the Office of Nuclear Waste Isolation (ONWI), Department of Energy (DOE). These issues are listed and discussed. 16 references, 9 figures

Iron fluxes to Talos Dome, Antarctica, over the past 200 kyr

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P. Vallelonga

2013-03-01

Full Text Available Atmospheric fluxes of iron (Fe over the past 200 kyr are reported for the coastal Antarctic Talos Dome ice core, based on acid leachable Fe concentrations. Fluxes of Fe to Talos Dome were consistently greater than those at Dome C, with the greatest difference observed during interglacial climates. We observe different Fe flux trends at Dome C and Talos Dome during the deglaciation and early Holocene, attributed to a combination of deglacial activation of dust sources local to Talos Dome and the reorganisation of atmospheric transport pathways with the retreat of the Ross Sea ice shelf. This supports similar findings based on dust particle sizes and fluxes and Rare Earth Element fluxes. We show that Ca and Fe should not be used as quantitative proxies for mineral dust, as they all demonstrate different deglacial trends at Talos Dome and Dome C. Considering that a 20 ppmv decrease in atmospheric CO2 at the coldest part of the last glacial maximum occurs contemporaneously with the period of greatest Fe and dust flux to Antarctica, we confirm that the maximum contribution of aeolian dust deposition to Southern Ocean sequestration of atmospheric CO2 is approximately 20 ppmv.

Transparent Inflatable Column Film Dome for Nuclear Stations, Stadiums, and Cities

Directory of Open Access Journals (Sweden)

Alexander Bolonkin

2011-01-01

Full Text Available In a series of previous articles, one of the authors published designs of the AB Dome which can cover a city, important large installations or subregions by a transparent thin film supported by a small additional air overpressure. The AB Dome keeps the outside atmospheric conditions from the interior protecting a city from chemical, bacterial, and radioactive weapons (wastes. The design in this article differs from previous one as this design employs an inflatable columns which does not need an additional pressure (overpressure inside the dome and is cheaper in construction (no powered air pumping station and in operation (no special entrance airlock and permanent pumping expense. When dome is supported by columns, no overpressure is required inside the dome which is important when the dome covers a damaged nuclear reactor. The nuclear reactor may produce radioactive gases and dust, and, as inflatable domes are not typically hermetically sealed, the increased pressure inside the dome can leak out gas and dust into the atmosphere. The suggested design does not have this drawback. Positive pressure gradients expel dust particles—neutral pressure gradients will not. (Negative pressure gradients may even be possible in certain configurations.

Evaluation of the structure and stratigraphy over Richton Dome, Mississippi

International Nuclear Information System (INIS)

Werner, M.L.

1986-05-01

The structure and stratigraphy over Richton Salt Dome, Mississippi, have been evaluated from 70 borings that were completed to various depths above the dome. Seven lithologic units have been identified and tentatively correlated with the regional Tertiary stratigraphy. Structure-contour and thickness maps of the units show the effects of dome growth from Eocene through early Pliocene time. Growth of the salt stock from late Oligocene through early Pliocene is estimated to have averaged 0.6 to 2.6 centimeters (0.2 to 1.1 inches) per 1000 years. No dome growth has occurred since the early Pliocene. The late Oligocene to early Pliocene strata over and adjacent to the dome reflect arching over the entire salt stock; some additional arching over individual centers may represent pre-Quaternary differential movement in the salt stock. The lithology and structure of the caprock at the Richton Salt Dome indicate that the caprock probably was completely formed by late Oligocene. In late Oligocene, the caprock was fractured by arching and altered by gypsum veining. Since late Oligocene, there are no indications of significant hydrologic connections through the caprock - that is, there are no indications of dissolution collapse or further anhydrite caprock accumulation. This structural and stratigraphic analysis provides insights on dome growth history, dome geometry, and neardome hydrostratigraphy that will aid in planning site characterization field activities, including an exploratory shaft, and in the conceptual design of a high-level waste (HLW) repository

Visualization and prediction of porosity in roller compacted ribbonswith near infrared chemical imaging (NIR-CI)

DEFF Research Database (Denmark)

Khorasani, Milad Rouhi; Amigo Rubio, Jose Manuel; Sonnergaard, Jørn

2015-01-01

The porosity of roller compacted ribbon is recognized as an important critical quality attribute which has a huge impact on the final product quality. The purpose of this study was to investigate the use of near-infrared chemical imaging (NIR-CI) for porosity estimation of ribbons produced...... and control of continuously operating roller compaction line....

Neuromuscular Responses of Elite Skaters During Different Roller Figure Skating Jumps

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Pantoja Patrícia Dias

2014-07-01

Full Text Available This study aimed to describe the neuromuscular activity of elite athletes who performed various roller figure skating jumps, to determine whether the muscle activation is greater during jumps with more rotations and in which phase the muscles are more active. This study also aimed to analyze if there is any difference in the muscle activity pattern between female and male skaters. Four elite skaters were evaluated, and each participated in two experimental sessions. During the first session, anthropometric data were collected, and the consent forms were signed. For the second session, neuromuscular data were collected during jumps, which were performed with skates at a rink. The following four roller figure skating jumps were evaluated: single Axel, double Axel, double Mapes and triple Mapes. The neuromuscular activity of the following seven muscles was obtained with an electromyograph which was fixed to the waist of each skater with a strap: biceps femoris, lateral gastrocnemius, tibialis anterior, rectus femoris, vastus lateralis, vastus medialis and gluteus maximus. The signal was transmitted wirelessly to a laptop. During the roller figure skating jumps, the lateral gastrocnemius, rectus femoris, vastus lateralis, biceps femoris and gluteus maximus, showed more activation during the jumps with more rotations, and the activation mainly occurred during the propulsion and flight phases. Female skaters demonstrated higher muscle activities in tibialis anterior, vastus lateralis, vastus medialis and gluteus maximus during the landing phase of the triple Mapes, when compared to their male counterparts. The results obtained in this study should be considered when planning training programs with specific exercises that closely resemble the roller figure skating jumps. This may be important for the success of elite skaters in competitions.

Neuromuscular Responses of Elite Skaters During Different Roller Figure Skating Jumps

Science.gov (United States)

Pantoja, Patrícia Dias; Mello, André; Liedtke, Giane Veiga; Kanitz, Ana Carolina; Cadore, Eduardo Lusa; Pinto, Stephanie Santana; Alberton, Cristine Lima; Kruel, Luiz Fernando Martins

2014-01-01

This study aimed to describe the neuromuscular activity of elite athletes who performed various roller figure skating jumps, to determine whether the muscle activation is greater during jumps with more rotations and in which phase the muscles are more active. This study also aimed to analyze if there is any difference in the muscle activity pattern between female and male skaters. Four elite skaters were evaluated, and each participated in two experimental sessions. During the first session, anthropometric data were collected, and the consent forms were signed. For the second session, neuromuscular data were collected during jumps, which were performed with skates at a rink. The following four roller figure skating jumps were evaluated: single Axel, double Axel, double Mapes and triple Mapes. The neuromuscular activity of the following seven muscles was obtained with an electromyograph which was fixed to the waist of each skater with a strap: biceps femoris, lateral gastrocnemius, tibialis anterior, rectus femoris, vastus lateralis, vastus medialis and gluteus maximus. The signal was transmitted wirelessly to a laptop. During the roller figure skating jumps, the lateral gastrocnemius, rectus femoris, vastus lateralis, biceps femoris and gluteus maximus, showed more activation during the jumps with more rotations, and the activation mainly occurred during the propulsion and flight phases. Female skaters demonstrated higher muscle activities in tibialis anterior, vastus lateralis, vastus medialis and gluteus maximus during the landing phase of the triple Mapes, when compared to their male counterparts. The results obtained in this study should be considered when planning training programs with specific exercises that closely resemble the roller figure skating jumps. This may be important for the success of elite skaters in competitions. PMID:25114728

Modeling of Comparative Performance of Asphalt Concrete under Hammer, Gyratory, and Roller Compaction

Directory of Open Access Journals (Sweden)

Saad I. Sarsam

2016-11-01

Full Text Available The main objective of this study is to develop predictive models using SPSS software (version 18 for Marshall Test results of asphalt mixtures compacted by Hammer, Gyratory, and Roller compaction. Bulk density of (2.351 gm/cc, at OAC of (4.7 % was obtained as a benchmark after using Marshall Compactor as laboratory compactive effort with 75-blows. Same density was achieved by Roller and Gyratory Compactors using its mix designed methods. A total of (75 specimens, for Marshall, Gyratory, and Roller Compactors have been prepared, based on OAC of (4.7 % with an additional asphalt contents of more and less than (0.5 % from the optimum value. All specimens have been subjected to Marshall Test. Mathematical models obtained indicated that variation of Marshall Stiffness is based on the variation of air voids. All of these models depend on asphalt cement content too.

Environmental assessment, Richton Dome site, Mississippi

International Nuclear Information System (INIS)

1986-05-01

The Nuclear Waste Policy Act of 1982 (42 USC Sections 10101-10226) requires the environmental assessment of a potential site to include a statement of the basis for the nomination of a site as suitable for characterization. Volume 2 of this environmental assessment provides a detailed evaluation of the Richton Dome Site and its suitability as the site for a radioactive waste disposal facility under DOE siting guidelines, as well as a comparison of the Richton Dome site with other proposed sites. Evaluation of the Richton Dome site is based on the reference repository design, but the evaluation will not change if based on the Mission Plan repository concept. The comparative evaluation of proposed sites is required under DOE guidelines, but is not intended to directly support the subsequent recommendation of three sites for characterization as candidate sites. 428 refs., 24 figs., 62 tabs

DETERMINATION OF ADHESIVE STRENGTH LAYER’S ROLLER COMPACTED CONCRETE THE METHOD AXIAL EXTENSION

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Tang Van Lam

2017-07-01

Full Text Available Roller compacted concrete for the construction of hydraulic and hydroelectric buildings is a composite material, which consists of a binder, fine aggregate (sand, coarse aggregate (gravel or crushed stone, water and special additives that provide the desired concrete workability and impart the required concrete performance properties. Concrete mixture is prepared at from concrete mixing plants strictly metered quantities of cement, water, additives and graded aggregates, whereupon they are delivered to the site laying Mixer Truck and sealing layers with each stack layer. The advantages of roller compaction technology should include the reduction of construction time, which allows fast commissioning construction projects, as well as reduce the amount of investment required. One of the main problems encountered in the process of roller compaction of the concrete mix is the need to provide the required adhesion strength between layers of concrete. This paper presents a method for determining the strength of adhesion between the concrete layers of different ages roller compacted concrete using axial tension. This method makes it possible to obtain objective and accurate results with a total thickness of layers of compacted concrete of up to 300…400 mm. Results from this method, studies have shown that the value of strength between the concrete layers in addition to the composition of the concrete and adhesion depends on the quality and the parallel end surfaces of the cylinder-models, which are mounted steel plates for axial tension, as well as the state of the contact surfaces of the concrete layer. The method can be used to determine the strength of interlayer adhesion in roller compacted concrete, which are used in the construction of dams and other hydraulic structures.

Effect of Silicon Nitride Balls and Rollers on Rolling Bearing Life

Science.gov (United States)

Zaretsky, Erwin V.; Vlcek, Brian L.; Hendricks, Robert C.

2005-01-01

Three decades have passed since the introduction of silicon nitride rollers and balls into conventional rolling-element bearings. For a given applied load, the contact (Hertz) stress in a hybrid bearing will be higher than an all-steel rolling-element bearing. The silicon nitride rolling-element life as well as the lives of the steel races were used to determine the resultant bearing life of both hybrid and all-steel bearings. Life factors were determined and reported for hybrid bearings. Under nominal operating speeds, the resultant calculated lives of the deep-groove, angular-contact, and cylindrical roller hybrid bearings with races made of post-1960 bearing steel increased by factors of 3.7, 3.2, and 5.5, respectively, from those calculated using the Lundberg-Palmgren equations. An all-steel bearing under the same load will have a longer life than the equivalent hybrid bearing under the same conditions. Under these conditions, hybrid bearings are predicted to have a lower fatigue life than all-steel bearings by 58 percent for deep-groove bearings, 41 percent for angular-contact bearings, and 28 percent for cylindrical roller bearings.

To Enhance the Fire Resistance Performance of High-Speed Steel Roller Door with Water Film System

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De-Hua Chung

2015-01-01

Full Text Available The structure of high-speed roller door with water film has improved in this study. The flameproof water film system is equipped with a water circulating device to reduce the water consumption of water film system. The water film is generated at the roller box of the high-speed roller door in this study. The heating test is done with the full-scale heating furnace. Both cases of the water film on unexposed surface and water film on exposed surface passed the fire resistance test based on ISO 834, proving that the high-speed roller door with water film system has 120A fire resistance period. The main findings indicate that the water film on exposed surface shows that as the amount of water film evaporated by high temperature inside the furnace must be greater than the evaporation capacity of water film on unexposed surface, the required water supply is 660 L more than the water film on unexposed surface.

Seismic experiments on Showa-Shinzan lava dome using firework shots

Science.gov (United States)

Miyamachi, Hiroki; Watanabe, Hidefumi; Moriya, Takeo; Okada, Hiromu

1987-11-01

Seismic experiments were conducted on Showa-Shinzan, a parasitic lava dome of volcano Usu, Hokkaido, which was formed during 1943 1945 activity. Since we found that firework shots fired on the ground can effectively produce seismic waves, we placed many seismometers on and around the dome during the summer festivals in 1984 and 1985. The internal structure had been previously studied using a prospecting technique employing dynamite blasts in 1954. The measured interval velocity across the dome in 1984 ranges 1.8 2.2 km/s drastically low compared to the results (3.0 4.0 km/s) in 1954; in addition, the velocity is 0.3 0.5 km/s higher than that in the surrounding area. The variation of the observed first arrival amplitudes can be explained by geometrical spreading in the high velocity lava dome. These observations show a marked change in the internal physical state of the dome corresponding to a drop in the measured highest temperature at fumaroles on the dome from 800°C in 1947 to 310°C in 1986.

Some aspects of the development of NW-German salt domes

International Nuclear Information System (INIS)

Jaritz, W.

1980-01-01

Aspects of the development of salt structures that may be of some importance to the safety of a final disposal site for radioactive waste are salt ascent and salt dissolution at the surface. The geological history of the salt domes is described in terms of the dissolution of the salt at the dome surface. In many cases it can be distinguished whether dissolution was caused by the ascent of the salt into strata containing groundwater by diapirism or by epeirogenic uplift or both. The salt domes of Wesendorf, Heide, and Marne are used as examples in a discussion of the transition from dissolution to the deposition of a cover of impermeable sediments. Moreover, the development of the Gorleben salt dome is described. The author's studies show the average rate of uplift of the NW-German salt domes in the diapiric stage to have ranged from a little less than 0.1 to about 0.5 mm per year. For salt domes in later stages, the rate of uplift is several hundredths of a millimeter per year at most. (orig.) [de

Assesment on Reproductive Performance and Hormonal Studies in Rural Women Beedi Rollers in Jagitial District of Telangana State

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Vanitha Baluka

2017-10-01

Full Text Available Beedi manufacturing is the second largest industry in India. It provides employment to millions of women mostly from the poor socioeconomic class. In North region of Telangana, beedi rolling is a major occupation for illiterate women in many villages. It may affect due to the inhalation of unfiltered tobacco dust and volatile and toxic components of tobacco. Biomonitoring of women beedi rollers and their reproductive performance assessment is necessary to take prevention/control the reproduction failure and carcinogen effect on cervical system. Continuous exposed to unfiltered tobacco dust may have systemic effect and lead to many disorders including hormone defects and reproductive health problems. Although studies have been carried out on beedi industry workers and tobacco smoke exposed people at national and international level, no such studies were carried out on women beedi rollers living in rural areas in Telangana State. Hence, this investigation is attempted to understand the study is find to association with hormonal levels and reproductive outcome in rural women beedi rollers of reproductive age in North Telangana. Statistical analysis was done for the obtained results to find the significance between the two groups for the reproductive outcome and Hormonal Studies. Total 50 women (married who are exposed minimum 6-10 years to the unfiltered tobacco dust beedi rollers in the age group of 25 to 45 years from villages of Jagitial district were enrolled for this study. 50 equal numbers of women in the same age group belonging to the same socio economic status and not exposed occupationally to chemical and physical agents was selected for comparison (control group. Estroidal, Progesterone the T3, T4 and TSH levels were measured found significantly T3, T4 levels were low in the beedi rollers, compared the controls. TSH levels were found to be higher in the beedi rollers. Estroidal and progesterone levels were obtained non

A Scalable and Modular Dome Illumination System for Scientific Microphotography on a Budget.

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Ricardo Kawada

Full Text Available A scalable and modular LED illumination dome for microscopic scientific photography is described and illustrated, and methods for constructing such a dome are detailed. Dome illumination for insect specimens has become standard practice across the field of insect systematics, but many dome designs remain expensive and inflexible with respect to new LED technology. Further, a one-size-fits-all dome cannot accommodate the large breadth of insect size encountered in nature, forcing the photographer to adapt, in some cases, to a less than ideal dome design. The dome described here is scalable, as it is based on a isodecahedron, and the template for the dome is available as a downloaded file from the internet that can be printed on any printer, on the photographer's choice of media. As a result, a photographer can afford, using this design, to produce a series of domes of various sizes and materials, and LED ring lights of various sizes and color temperatures, depending on the need.

The decorative program of the domes and area under the domes in the church of the monastery Resava

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Prolović Jadranka

2008-01-01

Full Text Available Because the dome is interpreted as a symbol of the heavens, it is reserved for heavenly subjects. The calotte of the dome is seen as a vault of heaven or 'heaven in the heavens' and, as such, as the 'house of Christ'. As the commentator in the 19th century reports, the image of Christ Pantokrator was once located at the zenith of the central dome of Resava. The preserved scenes and figures below the dome, specifically the heavenly liturgy and the prophets, confirm the original existence of this image. Together they build an iconology that was very widespread in late Byzantine art. The composition of the central dome of Resava resembles in its complete appearance, supported by some particularities, the central dome of Ravanica, which served as a model for the artists of Resava. One can find close parallels for the decoration of the side domes in Ravanica. The similar arrangement of heavenly powers in the tambours of the domes in Ravanica and Resava indicate that, like in Ravanica, Christ Emmanuel, the Age of Days, the Mother of God and the Archangel Michael could have been depicted in the zenith of the side domes of Resava. This type of decorative scheme in side domes is common in late Byzantine monumental painting. The remaining fragments with images of angels as deacons positioned in the ring around the zenith of the central dome show that the Heavenly Liturgy was depicted here, specifically the Large Entrance which, aside from the communion, was the only part of the liturgy visible to the faithful. In Resava, the Heavenly Liturgy is completed by the images of crowds of angels, which are portrayed in the tambours of the side domes. The liturgical hymns that accompany these images of angels confirm this order. The rendering of orders of angels in the tambours of the side domes in Resava comply with the traditional program in which these heavenly beings - who being closest to God, who were his first creations and the only to whom a look in the

Compressed sensing of roller bearing fault based on multiple down-sampling strategy

Science.gov (United States)

Wang, Huaqing; Ke, Yanliang; Luo, Ganggang; Tang, Gang

2016-02-01

Roller bearings are essential components of rotating machinery and are often exposed to complex operating conditions, which can easily lead to their failures. Thus, to ensure normal production and the safety of machine operators, it is essential to detect the failures as soon as possible. However, it is a major challenge to maintain a balance between detection efficiency and big data acquisition given the limitations of sampling theory. To overcome these limitations, we try to preserve the information pertaining to roller bearing failures using a sampling rate far below the Nyquist sampling rate, which can ease the pressure generated by the large-scale data. The big data of a faulty roller bearing’s vibration signals is firstly reduced by a down-sample strategy while preserving the fault features by selecting peaks to represent the data segments in time domain. However, a problem arises in that the fault features may be weaker than before, since the noise may be mistaken for the peaks when the noise is stronger than the vibration signals, which makes the fault features unable to be extracted by commonly-used envelope analysis. Here we employ compressive sensing theory to overcome this problem, which can make a signal enhancement and reduce the sample sizes further. Moreover, it is capable of detecting fault features from a small number of samples based on orthogonal matching pursuit approach, which can overcome the shortcomings of the multiple down-sample algorithm. Experimental results validate the effectiveness of the proposed technique in detecting roller bearing faults.

Compressed sensing of roller bearing fault based on multiple down-sampling strategy

International Nuclear Information System (INIS)

Wang, Huaqing; Ke, Yanliang; Luo, Ganggang; Tang, Gang

2016-01-01

Roller bearings are essential components of rotating machinery and are often exposed to complex operating conditions, which can easily lead to their failures. Thus, to ensure normal production and the safety of machine operators, it is essential to detect the failures as soon as possible. However, it is a major challenge to maintain a balance between detection efficiency and big data acquisition given the limitations of sampling theory. To overcome these limitations, we try to preserve the information pertaining to roller bearing failures using a sampling rate far below the Nyquist sampling rate, which can ease the pressure generated by the large-scale data. The big data of a faulty roller bearing’s vibration signals is firstly reduced by a down-sample strategy while preserving the fault features by selecting peaks to represent the data segments in time domain. However, a problem arises in that the fault features may be weaker than before, since the noise may be mistaken for the peaks when the noise is stronger than the vibration signals, which makes the fault features unable to be extracted by commonly-used envelope analysis. Here we employ compressive sensing theory to overcome this problem, which can make a signal enhancement and reduce the sample sizes further. Moreover, it is capable of detecting fault features from a small number of samples based on orthogonal matching pursuit approach, which can overcome the shortcomings of the multiple down-sample algorithm. Experimental results validate the effectiveness of the proposed technique in detecting roller bearing faults. (paper)

Type 1 neovascularization with polypoidal lesions complicating dome shaped macula

OpenAIRE

Naysan, Jonathan; Dansingani, Kunal K; Balaratnasingam, Chandrakumar; Freund, K Bailey

2015-01-01

Dome-shaped macula is described as an inward bulge of the macula within a posterior staphyloma in highly myopic eyes. Choroidal neovascularization is a known complication that can cause visual loss in dome-shaped macula. Herein, we describe a patient who presented with features of polypoidal choroidal neovascularization that developed on a background of high myopia with dome-shaped macula.

Validation of a Functional Pyelocalyceal Renal Model for the Evaluation of Renal Calculi Passage While Riding a Roller Coaster.

Science.gov (United States)

Mitchell, Marc A; Wartinger, David D

2016-10-01

The identification and evaluation of activities capable of dislodging calyceal renal calculi require a patient surrogate or validated functional pyelocalyceal renal model. To evaluate roller coaster facilitation of calyceal renal calculi passage using a functional pyelocalyceal renal model. A previously described adult ureteroscopy and renoscopy simulator (Ideal Anatomic) was modified and remolded to function as a patient surrogate. Three renal calculi of different sizes from the patient who provided the original computed tomographic urograph on which the simulator was based were used. The renal calculi were suspended in urine in the model and taken for 20 rides on the Big Thunder Mountain Railroad roller coaster at Walt Disney World in Orlando, Florida. The roller coaster rides were analyzed using variables of renal calculi volume, calyceal location, model position on the roller coaster, and renal calculi passage. Sixty renal calculi rides were analyzed. Independent of renal calculi volume and calyceal location, front seating on the roller coaster resulted in a passage rate of 4 of 24. Independent of renal calculi volume and calyceal location, rear seating on the roller coaster resulted in a passage rate of 23 of 36. Independent of renal calculi volume in rear seating, calyceal location differed in passage rates, with an upper calyceal calculi passage rate of 100%; a middle calyceal passage rate of 55.6%; and a lower calyceal passage rate of 40.0%. The functional pyelocalyceal renal model serves as a functional patient surrogate to evaluate activities that facilitate calyceal renal calculi passage. The rear seating position on the roller coaster led to the most renal calculi passages.

Spatial variations of growth within domes having different patterns of principal growth directions

Directory of Open Access Journals (Sweden)

Jerzy Nakielski

2014-01-01

Full Text Available Growth rate variations for two paraboloidal domes: A and B, identical when seen from the outside but differing in the internal pattern of principal growth directions, were modeled by means of the growth tensor and a natural coordinate system. In dome A periclinal trajectories in the axial plane were given by confocal parabolas (as in a tunical dome, in dome B by parabolas converging to the vertex (as in a dome without a tunica. Accordingly, two natural coordinate systems, namely paraboloidal for A and convergent parabolic for B, were used. In both cases, the rate of growth in area on the surfaces of domes was assumed to be isotropic and identical in corresponding points. It appears that distributions of growth rates within domes A and B are similar in their peripheral and central parts and different only in their distal regions. In the latter, growth rates are relatively large; the maximum relative rate of growth in volume is around the geometric focus in dome A, and on the surface around the vertex in dome B.

Pervasive liquid metal based direct writing electronics with roller-ball pen

Directory of Open Access Journals (Sweden)

Yi Zheng

2013-11-01

Full Text Available A roller-ball pen enabled direct writing electronics via room temperature liquid metal ink was proposed. With the rolling to print mechanism, the metallic inks were smoothly written on flexible polymer substrate to form conductive tracks and electronic devices. The contact angle analyzer and scanning electron microscope were implemented to disclose several unique inner properties of the obtained electronics. An ever high writing resolution with line width and thickness as 200 μm and 80 μm, respectively was realized. Further, with the administration of external writing pressure, GaIn24.5 droplets embody increasing wettability on polymer which demonstrates the pervasive adaptability of the roller-ball pen electronics.

Atmospheric scintillation at Dome C, Antarctica: implications for photometry and astrometry

Science.gov (United States)

Kenyon, S.; Lawrence, J.; Ashley, M. C. B.; Storey, J. W. V.; Tokovinin, A.; Fossat, E.

2006-08-01

Night-time turbulence profiles of the atmosphere above Dome C, Antarctica, were measured during 2004, using a MASS instrument. We compare this data with turbulence profiles above Cerro Tololo and Cerro Pachon, also measured with a MASS, and find, with the exception of the owest layer, that Dome C has significantly less turbulence. In addition, the integrated at turbulence 16 km above Dome C is always less than the median values at the two Chilean sites. Using average wind speed profiles, we assess the photometric noise produced by scintillation, and the atmospheric contribution to the error budget in narrow angle differential astrometry. In comparison with the two mid-latitude sites in Chile, Dome C offers a potential gain of about 3.6 in both photometric precision (for long integrations) and narrow-angle astrometry precision. Although the data from Dome C cover a fairly limited time frame, they lend strong support to expectations that Dome C will offer significant advantages for photometric and astrometric studies.

Characterization and growth mechanism of a peculiar nodular structure in shale: Comprehensive study over the Sitakund anticline, Bengal basin.

Science.gov (United States)

Gazi, M. Y.; Kabir, S. M. M.; Imam, M. B.

2017-12-01

Nodular shales commonly occur in comparatively older and silty shales near the axial (proximity to core) region of Sitakund Anticline (Study area), Sitapahar Anticline, Patharia Structure, Sylhet Anticline and Mirinja Anticline as observed. Stratigraphically, they are pronounced in the Surma group of Neogene succession. They are less abundant in limb portion. In many outcrop, they are found in the incompetent bed with the obliterated bedding bounded by well bedded competent beds. Their occurrence are sporadic rather than continuous along and across the strike of the bed. At some places huge number cluster of small and big nodular shales occur while in the other places, they occur as isolated mass in the highly disturbed or obliterated beds. The Surma group is the prime startigraphic unit in Bangladesh with major economic and academic importance. Yet there is a lack of comprehensive characterization of mudrocks of Surma group. This has prompted the present research to be undertaken. An initial field based study has been followed by detail textural, mineralogical, petrological and geochemical by using upscale laboratory techniques that include Thin Section Microscopy, Laser Particle Size Analyses, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and X-ray Florescence (XRF). From laser diffraction analysis, it is evident that nodular shales are silty in nature containing approximately 60% silt (Mainly quartz). XRD pattern shows that Nodular shale contains clay minerals, predominantly illite, Kaolinite, Chlorite and expandable mixed layer clay mineral. Detail geochemical analysis of some nodular shale samples shows that there are no significant variation from other samples in major and trace element concentration. Microcrack's within the quartz grains were observed in nodular shale. Projection of 15 nodular shale long axes in outcrop shows their orientation in NNW-SSE that is parallel to the fold axis. The study suggests a new name of conventionally called

High-energy roller injuries to the upper extremity.

Science.gov (United States)

Askins, G; Finley, R; Parenti, J; Bush, D; Brotman, S

1986-12-01

Eleven cases of high-energy industrial roller injuries treated between 1980 and 1984 were retrospectively reviewed. The dominant extremity was affected in nine. Six patients sustained fractures and/or dislocations, and three of these patients required fasciotomies for clinical signs of impending compartment syndromes. All fracture/dislocations, with the exception of a scapula fracture, anterior dislocation of a thumb interphalangeal joint, and a fractured coronoid process of the ulna, required open reduction with internal fixation. Three patients required split-thickness skin grafting for extensive skin degloving. Two patients required immediate amputation. Late sequelae included prolonged edema, nutritional depletion, neuroma formation of the superficial branch of the radial nerve, late carpal tunnel syndrome, and partial brachial plexus palsy. Industrial roller injuries continue to be an occupational hazard associated with more severe crushing trauma than the low-energy wringer washer injuries first described by MacCollum (11). Attention must be paid to the treatment of crushed skin, muscle, and nerves, fracture stabilization, nutritional support, and occupational therapy. Concurrent monitoring for signs of a developing compartment syndrome and complications of rhabdomyolysis is essential.

Structure and evolution of an active resurgent dome evidenced by geophysical investigations: The Yenkahe dome-Yasur volcano system (Siwi caldera, Vanuatu)

Science.gov (United States)

Brothelande, E.; Lénat, J.-F.; Chaput, M.; Gailler, L.; Finizola, A.; Dumont, S.; Peltier, A.; Bachèlery, P.; Barde-Cabusson, S.; Byrdina, S.; Menny, P.; Colonge, J.; Douillet, G. A.; Letort, J.; Letourneur, L.; Merle, O.; Di Gangi, F.; Nakedau, D.; Garaebiti, E.

2016-08-01

In this contribution, we focus on one of the most active resurgences on Earth, that of the Yenkahe dome in the Siwi caldera (Tanna Island, Vanuatu), which is associated with the persistently active Yasur volcano. Gravity and magnetic surveys have been carried out over the past few years in the area, as well as electrical methods including electrical resistivity tomography (ERT), time domain electro-magnetics (TDEM) and self-potential (SP). These investigations were completed by thermometry, CO2 soil gas measurements, field observations and sampling. This multi-method approach allows geological structures within the caldera to be identified, as well as associated hydrothermal features. The global structure of the caldera is deduced from gravity data, which shows the caldera rim as a high density structure. Large lava fields, emplaced before and after the onset of resurgence, are evidenced by combined gravity, magnetic and resistivity signals. In the middle of the caldera, the Yenkahe dome apparently results from a combination of volcanic and tectonic events, showing that lava extrusion and resurgence have been operating simultaneously or alternately during the Siwi caldera post-collapse history. There is a clear distinction between the western and eastern parts of the dome. The western part is older and records the growth of an initial volcanic cone and the formation of a small caldera. This small caldera (paleo-Yasur caldera), partially filled with lava flows, is the present-day focus of volcanic activity and associated fluid circulation and alteration. The eastern part of the dome is presumably younger, and is characterized by intense, extensive hydrothermal alteration and activity. Its northern part is covered by lava flow piles and exhibits a shallow hydrothermal zone in ERT. The southern part has hydrothermal alteration and activity extending at least down to the base of the resurgent dome. This part of the dome is built up of low cohesion rock and is thus

Scale up of diesel oil biodegradation in a baffled roller bioreactor.

Science.gov (United States)

Nikakhtari, Hossein; Song, Wanning; Kumar, Pardeep; Nemati, Mehdi; Hill, Gordon A

2010-05-01

Diesel oil is a suitable substance to represent petroleum contamination from accidental spills in operating and transportation facilities. Using a microbial culture enriched from a petroleum contaminated soil, biodegradation of diesel oil was carried out in 2.2, 55, and 220 L roller baffled bioreactors. The effects of bioreactor rotation speed (from 5 to 45 rpm) and liquid loading (from 18% to 73% of total volume) on the biodegradation of diesel oil were studied. In the small scale bioreactor (2.2L), the maximum rotation speed of 45 rpm resulted in the highest biodegradation rate with a first order biodegradation kinetic constant of 0.095 d(-1). In the larger scale bioreactors, rotation speed did not affect the biodegradation rate. Liquid loadings higher than 64% resulted in reduced biodegradation rates in the small scale bioreactor; however, in the larger roller bioreactors liquid loading did not affect the biodegradation rate. Biodegradation of diesel oil at 5 rpm and 73% loading is recommended for operating large scale roller baffled bioreactors. Under these conditions, high diesel oil concentrations up to 50 gL(-1) can be bioremediated at a rate of 1.61 gL(-1)d(-1). Copyright 2010 Elsevier Ltd. All rights reserved.

The dynamic analysis of drum roll lathe for machining of rollers

Science.gov (United States)

Qiao, Zheng; Wu, Dongxu; Wang, Bo; Li, Guo; Wang, Huiming; Ding, Fei

2014-08-01

An ultra-precision machine tool for machining of the roller has been designed and assembled, and due to the obvious impact which dynamic characteristic of machine tool has on the quality of microstructures on the roller surface, the dynamic characteristic of the existing machine tool is analyzed in this paper, so is the influence of circumstance that a large scale and slender roller is fixed in the machine on dynamic characteristic of the machine tool. At first, finite element model of the machine tool is built and simplified, and based on that, the paper carries on with the finite element mode analysis and gets the natural frequency and shaking type of four steps of the machine tool. According to the above model analysis results, the weak stiffness systems of machine tool can be further improved and the reasonable bandwidth of control system of the machine tool can be designed. In the end, considering the shock which is caused by Z axis as a result of fast positioning frequently to feeding system and cutting tool, transient analysis is conducted by means of ANSYS analysis in this paper. Based on the results of transient analysis, the vibration regularity of key components of machine tool and its impact on cutting process are explored respectively.

Wide-scan dielectric dome antenna with reduced profile

NARCIS (Netherlands)

Gandini, E.; Silvestri, F.; Benini, A.; Gerini, G.; Martini, E.; Maci, S.; Viganò, M.C.; Toso, G.; Monni, S.

2017-01-01

In this contribution, a dielectric dome antenna design in Ka-band is presented. The dome antenna is based on the combination of a phased array and a dielectric lens. The goal of the combination of these structures is to enlarge the field of view of the antenna. In particular, the array is considered

Dynamic response of domes in CANDU 600 MWe containments

International Nuclear Information System (INIS)

Aziz, T.S.; Meng, V.; Alizadeh, A.

1981-01-01

CANDU reactors of the 600 MWe type are typically housed in a cylindrical prestressed concrete containment structure; rising from a flat slab and ending in a domed roof. The principal components of this structure are: (a) a circular base slab, (b) a vertical cylinder and (c) a spherical dome cap. A unique feature of a CANDU 600 MWe containment structure is the existence of an inner spherical concrete dome, located below the outer spherical dome, which serves as the bottom of a reservoir for the storage of 560,000 imperial gallons of douzing water. The thickness of the prestressed cylinder wall is approximately doubled between the two domes to create a ring beam. Inside the containment there exists an internal concrete structure which is independent of the containment structure except for support on the base slab. The containment boundary is a fully prestressed concrete structure. This paper deals with the seismic behaviour of the CANDU 600 MWe containment structure and the effect of its unique features; such as the lower dome and the douzing water on this behaviour. The objective of the study is to evaluate the interaction (coupling) effects between the different components of the structure. The approach taken is to study each component of the structure individually, then an assembly of the different components, and finally the total containment structure. This presentation is limited to the vertical response of the structure under a vertical earthquake only. Axisymmetric finite elements were used in all models. The vertical responses at selected points of the structure were obtained by the response spectrum method as well as the time-history method. It was observed that the response spectrum method over-estimates the vertical response of the domes and under-estimates the vertical responses of the ring girder and the containment cylinder compared to the time-history method. (orig./RW)

Fabrication of a roller type PDMS stamp using SU-8 concave molds and its application for roll contact printing

International Nuclear Information System (INIS)

Park, Jongho; Kim, Beomjoon

2016-01-01

Continuous fabrication of micropatterns at low-cost is attracting attention in various applications within industrial fields. To meet such demands, we have demonstrated a roll contact printing technique, using roller type polydimethylsiloxane (PDMS) stamps with roll-to-flat and roll-to-roll stages. Roller type PDMS stamps for roll contact printing were fabricated using a custom-made metal support and SU-8 microstructures fabricated on concave substrates as a mold. The molding/casting method which we developed here provided faster and easier fabrication than conventional methods for roller type stamps. Next, roll contact printing was performed using fabricated roller type PDMS stamps with roll-to-flat and roll-to-roll stages. Patterns with minimum widths of 3 μm and 2.1 μm were continuously fabricated for each stage, respectively. In addition, the relationship between applied pressures and dimensional changes of roll contact printed patterns was investigated. Finally, we confirmed that roll contact printing and the new fabrication method for roller stamps presented in this study demonstrated the feasibility for industrial applications. (paper)

Geological and hydrological exploration of Gulf Coast Salt Domes

International Nuclear Information System (INIS)

Laughon, R.B.

1979-01-01

The geologic exploration program in the Gulf Coast Salt Dome Region is based on a screening process that includes a series of increasingly detailed studies. The screening procedure takes the following steps: (1) determination of regions for further study (in this case, the salt domes of the interior Gulf Coast); (2) regional surveys and the determination of areas within those regions which are thought to be most suitable and which are recommended for further evaluation (in this case, eight specific salt domes); (3) area characterizations and the determination of locations within the areas which are thought to have a high probability of suitability (in this case, two or three of the eight salt domes); (4) location studies and the determination of a potential repository site, which is thought to be suitable and licensable and which is recommended for completion of site characterization studies

THEMIS Observations of Domes and Associated Lineaments in Arcadia Planitia

Science.gov (United States)

Milam, K. A.; McSween, H. Y.

2003-12-01

The northern plains of Mars contain several high concentrations (Acidalia, Utopia, Elysium, etc.) of small (System (THEMIS), visible images from THEMIS and the Mars Orbiter Camera, and elevation data from the Mars Orbiter Laser Altimeter were used to study a 390,000 km 2 area ˜1500 km to the northwest of Elysium Mons. Of interest is a region centered on Tyndall crater and bordered by Phlegras Montes to the west. The area is characterized by gentle, westward-sloping plains, with noticeable slope breaks along several N-S trending wrinkle ridges. Several hundred circular domes dot this area. Domes display features consistent with a volcanic origin. Most are circular to slightly elliptical at their base, with basal diameters ranging from 0.5-6 km. Summits typically rise material (as compared to the coarser-grained summits). Less than 25% of domes appear to have summit depressions and ~ 1% show fractured summit areas. Some domes appear to be randomly distributed, but many are aligned in chains according to wrinkle ridge orientations. Using THEMIS data, we have detected over 165 domes that are aligned with and superimposed upon over 145 lineaments. Most lineaments are cut by lineaments. No laterally extensive flows have been detected as emanating from lineaments, nor have similar lineaments been detected immediately outside the study area. The association of domes and lineaments is consistent with observations of volcanic constructs along open fissures in many terrestrial volcanic fields. Assuming a volcanic origin, the dome-lineament relationship suggests localized, structurally-controlled eruptions along open fissures. Initial extension caused the opening of fractures, which was followed by localized extrusions. Such localized development can provide information about eruption rates, magma compositions, or the physical properties of erupted lava. Either during or after volcanic activity, continued extension led to several domes being dissected by fissures.

Visualization in mechanics: the dynamics of an unbalanced roller

Science.gov (United States)

Cumber, Peter S.

2017-04-01

It is well known that mechanical engineering students often find mechanics a difficult area to grasp. This article describes a system of equations describing the motion of a balanced and an unbalanced roller constrained by a pivot arm. A wide range of dynamics can be simulated with the model. The equations of motion are embedded in a graphical user interface for its numerical solution in MATLAB. This allows a student's focus to be on the influence of different parameters on the system dynamics. The simulation tool can be used as a dynamics demonstrator in a lecture or as an educational tool driven by the imagination of the student. By way of demonstration the simulation tool has been applied to a range of roller-pivot arm configurations. In addition, approximations to the equations of motion are explored and a second-order model is shown to be accurate for a limited range of parameters.

Effects of frequency on gross efficiency and performance in roller ski skating.

Science.gov (United States)

Leirdal, S; Sandbakk, O; Ettema, G

2013-06-01

The purpose of the present study was to examine the effect of frequency on efficiency and performance during G3 roller ski skating. Eight well-trained male cross-country skiers performed three submaximal 5-min speeds (10, 13, and 16 km/h) and a time-to-exhaustion (TTE) performance (at 20 km/h) using the G3 skating technique using freely chosen, high, and low frequency at all four speeds. All tests were done using roller skis on a large treadmill at 5% incline. Gross efficiency (GE) was calculated as power divided by metabolic rate. Power was calculated as the sum of power against frictional forces and power against gravity. Metabolic rate was calculated from oxygen consumption and blood lactate concentration. Freely chosen frequency increased from 60 to 70 strokes/min as speed increased from 10 to 20 km/h. GE increased with power. At high power (20 km/h performance test), both efficiency and performance were significantly reduced by high frequency. In regard to choice of frequency during G3 roller ski skating, cross-country skiers seems to be self-optimized both in relation to energy saving (efficiency) and performance (TTE). © 2011 John Wiley & Sons A/S.

Experimental study and numerical optimization of tensegrity domes - A case study

Science.gov (United States)

Winkelmann, Karol; Kłos, Filip; Rąpca, Mateusz

2018-01-01

The paper deals with the design, experimental analysis and numerical optimization of tensegrity dome models. Two structures are analyzed - a Geiger system dome (preliminary dome), with PVC-U bars and PA6/PP/PET tendons and a Fuller system dome (target dome), with wooden bars and steel cables as tendons. All used materials are experimentally tested in terms of Young's modulus and yield stress values, the compressed bars are also tested for the limit length demarcating the elastic buckling from plastic failure. The data obtained in experiments is then implemented in SOFiSTiK commercial software FE model. The model's geometrical parameters are considered uniform random variables. Geometrically and materially nonlinear analysis is carried out. Based on the obtained structural response (displacements), a Monte Carlo simulation - based approach is incorporated for both structural design point formulation and the SLS requirements fulfillment analysis. Finally, an attempt is made to erect the Fuller dome model in order to compare the numerical results of an experimentally-derived model with the in situ measurements of an actual structure.

Teapot Dome: past, present, and future

Energy Technology Data Exchange (ETDEWEB)

Curry, W.H. Jr.

1977-05-01

The Teapot Dome field is the 99th largest oil field in the United States with a proved reserve of 42,515,000 bbl, yet the field is sparsely drilled and underdeveloped. The writer credits Naval Petroleum Reserve No. 3 with 38 million bbl of future reserves. The long history of Teapot Dome since the early 1900s, sometimes turbulent, sometimes dormant, was marred by government scandal, akin to Watergate in notoriety, in the 1920s. Harry F. Sinclair's Mammoth Oil Company obtained leases from the Department of the Interior in a fraudulent manner which led to prison sentences for some of the principals. Oil production in the Teapot Dome field is from three formations; the shallow Shannon at depths of 400 to 1,000 ft (122 to 305 m); the Second Wall Creek member of the Frontier Formation at 2,500 to 3,000 ft (362 to 914 m); and the Tensleep Sandstone at 5,500 ft (1,676 m). The Second Wall Creek is the principal producing sandstone and has the greatest future production potential. Current production is small. As of December 1973, each of the 42 Navy wells averaged 4.4 b/d from the Shannon Sandstone, and 49 offset wells averaged 2.2 b/d each. In the Second Wall Creek, each of the 23 Navy wells averaged 10 b/d and 8 offset wells averaged 14.9 b/d each. Total daily production was 416 bbl and grand total for Teapot Dome through December 1975 was 7,762,709 bbl.

Late Pleistocene acceleration of deformation across the northern Tianshan piedmont (China) evidenced from the morpho-tectonic evolution of the Dushanzi anticline

Science.gov (United States)

Charreau, Julien; Saint-Carlier, Dimitri; Lavé, Jérôme; Dominguez, Stéphane; Blard, Pierre-Henri; Avouac, Jean-Philippe; Brown, Nathan D.; Malatesta, Luca Claude; Wang, Shengli; Rhodes, Edward J.

2018-04-01

We document the temporal evolution of deformation in the northern Tianshan piedmont where the deformation is partitioned across several thrusts and folds. We focus on the Dushanzi anticline, where abandoned terraces and growth strata allow us to constrain the history of folding since the Miocene. Based on subsurface seismic imaging, structural measurements and morphological analysis, we show that this anticline is associated with two decollement levels. We use kink band migration in growth strata dated by paleomagnetism to constrain the shortening from the Mio-Pliocene to the Holocene. Our results show that the Dushanzi anticline has been active since at least 8 Ma and that the fold grew at a steady shortening rate of 0.6 ± 0.1 mm/yr from 8 to 1.5 Ma with possible variations from 2.5 to 1.5 Ma. Then it accelerated rapidly to a rate of 4.3 ± 1.0 mm/yr over at least the last 100 ka. These results, together with similar temporal shortening evolutions across other structures, suggest that the deformation rate across the eastern Tianshan piedmont increased relatively recently. This may reflect either a redistribution of the deformation from the internal structures toward the borders or a general acceleration of the deformation across the entire range.

Environmental assessment, Richton Dome site, Mississippi (US)

Energy Technology Data Exchange (ETDEWEB)

none,

1986-05-01

The Nuclear Waste Policy Act of 1982 (42 USC Sections 10101-10226) requires the environmental assessment of a potential site to include a statement of the basis for the nomination of a site as suitable for characterization. Volume 2 of this environmental assessment provides a detailed evaluation of the Richton Dome Site and its suitability as the site for a radioactive waste disposal facility under DOE siting guidelines, as well as a comparison of the Richton Dome site with other proposed sites. Evaluation of the Richton Dome site is based on the reference repository design, but the evaluation will not change if based on the Mission Plan repository concept. The comparative evaluation of proposed sites is required under DOE guidelines, but is not intended to directly support the subsequent recommendation of three sites for characterization as candidate sites. 428 refs., 24 figs., 62 tabs. (MHB)

Geological evaluation of Gulf Coast salt domes: overall assessment of the Gulf Interior Region

International Nuclear Information System (INIS)

1981-10-01

The three major phases in site characterization and selection are regional studies, area studies, and location studies. This report characterizes regional geologic aspects of the Gulf Coast salt dome basins. It includes general information from published sources on the regional geology; the tectonic, domal, and hydrologic stability; and a brief description the salt domes to be investigated. After a screening exercise, eight domes were chosen for further characterization: Keechi, Oakwood, and Palestine Domes in Texas; Vacherie and Rayburn's domes in North Louisiana; and Cypress Creek and Richton domes in Mississippi. A general description of each, maps of the location, property ownership, and surface geology, and a geologic cross section were presented for each dome

Geological evaluation of Gulf Coast salt domes: overall assessment of the Gulf Interior Region

Energy Technology Data Exchange (ETDEWEB)

None

1981-10-01

The three major phases in site characterization and selection are regional studies, area studies, and location studies. This report characterizes regional geologic aspects of the Gulf Coast salt dome basins. It includes general information from published sources on the regional geology; the tectonic, domal, and hydrologic stability; and a brief description the salt domes to be investigated. After a screening exercise, eight domes were chosen for further characterization: Keechi, Oakwood, and Palestine Domes in Texas; Vacherie and Rayburn's domes in North Louisiana; and Cypress Creek and Richton domes in Mississippi. A general description of each, maps of the location, property ownership, and surface geology, and a geologic cross section were presented for each dome.

The anticline presence in The Salinas zone, Burruyacu department, Tucuman, Republica Argentina

International Nuclear Information System (INIS)

Bortolotti, P; Falcon, C. Universidad Nacional de Tucuman. Argentina

2010-01-01

This paper is about the use of aerial photographs to determine the existence of surface structures recently evidenced by the masking produced by deforestation, soil movement and agriculture, in a foothill region of the Tucuman province. The photo geological observations were confirmed by geological and structural determinations of surface, showing the presence of an anticline with the core surrounded by the stratums as well as easily recognizable by their different colors and apparent thickness. The photographs and satellite images highlights the fractionation of the complex wi ch affects the Tertiary (Pliocene) and Quaternary (Pleistocene) sediments period

Dome-shaped macula: a compensatory mechanism in myopic anisometropia?

Science.gov (United States)

Keane, Pearse A; Mitra, Arijit; Khan, Imran J; Quhill, Fahd; Elsherbiny, Samer M

2012-05-31

The purpose of this article was to describe a patient with dome-shaped macula in the setting of mild myopic anisometropia and to speculate regarding the role of this feature as a compensatory mechanism in ocular development. The clinical records of a 49-year-old woman with this condition were reviewed. Spectral-domain optical coherence tomographic images revealed evidence of a dome-shaped macula. B-scan ultrasonography measured axial lengths of 23.8 mm in the right eye and 22.8 mm in the left eye. Spherical equivalents were -1.375 and +0.375 in the right and left eyes, respectively. Examination of the left eye was unremarkable. Dome-shaped macula has previously only been described in patients with high myopia. These findings support the hypothesis that myopic anisometropia, rather than absolute refractive status, is central to the development of dome-shaped macula and that this feature represents a protective mechanism aimed at reducing the effects of anisometropia. Copyright 2012, SLACK Incorporated.

Corrective action plan for CAU No. 404: Roller Coaster Sewage Lagoons and North Disposal Trench, Tonopah Test Range

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-07-01

This Corrective Action Plan (CAP) provides the selected corrective action alternative and proposes the closure implementation methodology for the Roller Coaster Sewage Lagoons and North Disposal Trench Corrective Action Unit (CAU) No. 404. The site is located on the Tonopah Test Range. CAU 404 consists of two Corrective Action Sites (CAS): the Roller Coaster Lagoons (CAS No TA-03-001-TA-RC) and the North Disposal Trench (CAS No TA-21-001-TA-RC). A site map of the lagoons and trench is provided. The Roller Coaster Sewage Lagoons are comprised of two unlined lagoons that received liquid sanitary waste in 1963 from the Operation Roller Coaster Man Camp and debris from subsequent construction and range cleanup activities. The North Disposal Trench was excavated in approximately 1963 and received solid waste and debris from the man camp and subsequent construction and range cleanup activities. A small hydrocarbon spill occurred during the 1995 Voluntary Corrective Action (VCA) activities in an area associated with the North Disposal Trench CAS.

Corrective action plan for CAU No. 404: Roller Coaster Sewage Lagoons and North Disposal Trench, Tonopah Test Range

International Nuclear Information System (INIS)

1997-07-01

This Corrective Action Plan (CAP) provides the selected corrective action alternative and proposes the closure implementation methodology for the Roller Coaster Sewage Lagoons and North Disposal Trench Corrective Action Unit (CAU) No. 404. The site is located on the Tonopah Test Range. CAU 404 consists of two Corrective Action Sites (CAS): the Roller Coaster Lagoons (CAS No TA-03-001-TA-RC) and the North Disposal Trench (CAS No TA-21-001-TA-RC). A site map of the lagoons and trench is provided. The Roller Coaster Sewage Lagoons are comprised of two unlined lagoons that received liquid sanitary waste in 1963 from the Operation Roller Coaster Man Camp and debris from subsequent construction and range cleanup activities. The North Disposal Trench was excavated in approximately 1963 and received solid waste and debris from the man camp and subsequent construction and range cleanup activities. A small hydrocarbon spill occurred during the 1995 Voluntary Corrective Action (VCA) activities in an area associated with the North Disposal Trench CAS

Optimised intake stroke analysis for flat and dome head pistons ...

African Journals Online (AJOL)

Optimised intake stroke analysis for flat and dome head pistons. ... in understanding the performance characteristics optioned between flat head and dome head pistons in engine design. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

Underwater Calibration of Dome Port Pressure Housings

Science.gov (United States)

Nocerino, E.; Menna, F.; Fassi, F.; Remondino, F.

2016-03-01

Underwater photogrammetry using consumer grade photographic equipment can be feasible for different applications, e.g. archaeology, biology, industrial inspections, etc. The use of a camera underwater can be very different from its terrestrial use due to the optical phenomena involved. The presence of the water and camera pressure housing in front of the camera act as additional optical elements. Spherical dome ports are difficult to manufacture and consequently expensive but at the same time they are the most useful for underwater photogrammetry as they keep the main geometric characteristics of the lens unchanged. Nevertheless, the manufacturing and alignment of dome port pressure housing components can be the source of unexpected changes of radial and decentring distortion, source of systematic errors that can influence the final 3D measurements. The paper provides a brief introduction of underwater optical phenomena involved in underwater photography, then presents the main differences between flat and dome ports to finally discuss the effect of manufacturing on 3D measurements in two case studies.

Vibratory synchronization transmission of a cylindrical roller in a vibrating mechanical system excited by two exciters

Science.gov (United States)

Zhang, Xueliang; Wen, Bangchun; Zhao, Chunyu

2017-11-01

In present work vibratory synchronization transmission (VST) of a cylindrical roller with dry friction in a vibrating mechanical system excited by two exciters, is studied. Using the average method, the criterion of implementing synchronization of two exciters and that of ensuring VST of a roller, are achieved. The criterion of stability of the synchronous states satisfies the Routh-Hurwitz principle. The influences of the structural parameters of the system to synchronization and stability, are discussed numerically, which can be served as the theoretical foundation for engineering designs. An experiment is carried out, which approximately verify the validity of the theoretical and numerical results, as well as the feasibility of the method used. Utilizing the VST theory of a roller, some types of vibrating crushing or grinding equipments, etc., can be designed.

Granule fraction inhomogeneity of calcium carbonate/sorbitol in roller compacted granules

DEFF Research Database (Denmark)

Bacher, Charlotte; Olsen, P.M.; Bertelsen, P.

2008-01-01

The granule fraction inhomogeneity of roller compacted granules was examined on mixtures of three different morphologic forms of calcium carbonate and three particle sizes of sorbitol. The granule fraction inhomogeneity was determined by the distribution of the calcium carbonate in each of the 10...... size fractions between 0 and 2000 µm and by calculating the demixing potential. Significant inhomogeneous occurrence of calcium carbonate in the size fractions was demonstrated, depending mostly on the particles sizes of sorbitol but also on the morphological forms of calcium carbonate......, the ability of the powder to agglomerate in the roller compactor was demonstrated to be related to the ability of the powder to be compacted into a tablet, thus the most compactable calcium carbonate and the smallest sized sorbitol improved the homogeneity by decreasing the demixing potential....

Numerical analysis of pressure and porosity evolution in lava domes during periodic degassing conditions

Science.gov (United States)

Hyman, D.; Bursik, M. I.; Pitman, E. B.

2017-12-01

The collapse or explosive breakup of growing and degassing lava domes presents a significant hazard due to the generation of dense, mobile pyroclastic flows as well as the wide dispersal of dense ballistic blocks. Lava dome stability is in large part governed by the balance of transport and storage of gas within the pore space. Because pore pressurization reduces the effective stress within a dome, the transient distribution of elevated gas pressure is critically important to understanding dome break up. We combine mathematical and numerical analyses to gain a better understanding of the temporal variation in gas flow and storage within the dome system. In doing so, we develop and analyze new governing equations describing nonlinear gas pressure diffusion in a deforming dome with an evolving porosity field. By relating porosity, permeability, and pressure, we show that the flux of gas through a dome is highly sensitive to the porosity distribution and viscosity of the lava, as well as the timescale and magnitude of the gas supply. The numerical results suggest that the diffusion of pressure and porosity variations play an integral role in the cyclic growth and destruction of small domes.The nearly continuous cycles of lava dome growth, pressurization, and failure that have characterized the last two decades of eruptive history at Volcán Popocatépetl, Mexico provide excellent natural data with which to compare new models of transient dome pressurization. At Popocatépetl, periodic pressure increases brought on by changes in gas supply into the base of the dome may play a role in its cyclic growth and destruction behavior. We compare our model of cyclic pressurization with lava dome survival data from Popocatépetl. We show that transient changes in pore pressure explain how small lava domes evolve to a state of criticality before explosion or collapse. Additionally, numerical analyses presented here suggest that short-term oscillations cannot arise within the dome

Influence of quartz particles on wear in vertical roller mills

DEFF Research Database (Denmark)

Jensen, Lucas R.D.; Friis, Henrik; Fundal, Erling

2010-01-01

The standard closed circuit comminution process commonly employed in industrial vertical roller mills has been analyzed to determine the influence of typical abrasive minerals on wear rates. With the main focus on raw mixes used in cement plants, synthetic mixtures imitating were prepared. Using...

DOMe: A deduplication optimization method for the NewSQL database backups.

Directory of Open Access Journals (Sweden)

Longxiang Wang

Full Text Available Reducing duplicated data of database backups is an important application scenario for data deduplication technology. NewSQL is an emerging database system and is now being used more and more widely. NewSQL systems need to improve data reliability by periodically backing up in-memory data, resulting in a lot of duplicated data. The traditional deduplication method is not optimized for the NewSQL server system and cannot take full advantage of hardware resources to optimize deduplication performance. A recent research pointed out that the future NewSQL server will have thousands of CPU cores, large DRAM and huge NVRAM. Therefore, how to utilize these hardware resources to optimize the performance of data deduplication is an important issue. To solve this problem, we propose a deduplication optimization method (DOMe for NewSQL system backup. To take advantage of the large number of CPU cores in the NewSQL server to optimize deduplication performance, DOMe parallelizes the deduplication method based on the fork-join framework. The fingerprint index, which is the key data structure in the deduplication process, is implemented as pure in-memory hash table, which makes full use of the large DRAM in NewSQL system, eliminating the performance bottleneck problem of fingerprint index existing in traditional deduplication method. The H-store is used as a typical NewSQL database system to implement DOMe method. DOMe is experimentally analyzed by two representative backup data. The experimental results show that: 1 DOMe can reduce the duplicated NewSQL backup data. 2 DOMe significantly improves deduplication performance by parallelizing CDC algorithms. In the case of the theoretical speedup ratio of the server is 20.8, the speedup ratio of DOMe can achieve up to 18; 3 DOMe improved the deduplication throughput by 1.5 times through the pure in-memory index optimization method.

Prevention of Roller Bearing-Initiated Burnoffs in Railroad Freight Car Journals

Science.gov (United States)

1979-01-01

The objective of this program was to determine the technical feasibility and cost effectiveness of constructing three separate devices for the prevention of catastrophic roller bearing-initiated, railroad journal failure. 1. Construction of a low cos...

Hyperthyroidism with dome-and-dart T wave: A case report

Science.gov (United States)

Lai, Ping; Yuan, Jing-ling; Xue, Jin-hua; Qiu, Yue-qun

2017-01-01

Abstract Rationale: Dome-and-dart T waves (or bifid T waves) are a rare phenomenon in the surface electrocardiogram. These wave forms are mainly observed in patients with congenital heart disease such as atrial septal defect and ventricular septal defect. And hyperthyroidism who presented with an electrocardiogram that had dome-and-dart T waves in a precordial lead is never been reported. Patient concerns: The patient presented with continuous tachycardia, palpitations, chest tightness, and headache for 4 days, and aggravated for 1 day. Diagnoses: Hyperthyroidism. Interventions: Methimazole. Outcomes: All symptoms were alleviated. Lessons: Dome-and-dart or bifid T waves have been reported in the conventional 12-lead electrocardiograms in some patients with congenital heart disease. The case illustrated here, to the best of our knowledge, dome-and-dart or bifid T waves may associate with hyperthyroidism patients. PMID:28178156

Twist deformation in anticlinic antiferroelectric structure in smectic B.sub.2./sub. imposed by the surface anchoring

Czech Academy of Sciences Publication Activity Database

Lejček, Lubor; Novotná, Vladimíra; Glogarová, Milada

2008-01-01

Roč. 35, č. 1 (2008), s. 11-19 ISSN 0267-8292 R&D Projects: GA ČR GA202/05/0431 Institutional research plan: CEZ:AV0Z10100520 Keywords : smectic liquid crystals * bent-shaped molecules * anticlinic antiferroelectric structure * ferroelectric structure * twist deformation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.132, year: 2008

Physical and mechanical behaviour of a roller compacted concrete ...

African Journals Online (AJOL)

In order to study the behaviour of a roller compacted concrete (RCC) reinforced with polypropylene fiber, six types of RCC were made with different content of fibers (0, 0.5, 1, 1.5, 2 and 2.5 Kg/m3). The physical parameters are the density, the workability, the shrinkage and the water absorption. For the mechanical ...

Experimental performance investigation of glazing system combined with internal roller blinds

DEFF Research Database (Denmark)

Larsen, Olena Kalyanova; Jensen, Rasmus Lund; Iversen, Tore Dahl

2016-01-01

Modern low-energy buildings are often associated with efficient shading devices, as an inevitable component to reduce the peak heat gain in the building and to improve visual comfort. Internal shading devices may have inferior performance compared to external shading, but these are still the most...... used in practice due to lower cost, simplicity and better acceptance between architects and users. The interplay between glazing systems and internal shading devices has been studied and in everyday practice this interplay is described by the solar shading coefficient and the total g......-value of the system (window + roller blind). Solar shading coefficient in such practice is assumed to be independent of the window properties and solar incidence angle. This paper is aimed to illustrate the deviation between the actual and assumed performance of the window system with internal roller blind. This task...

Effect of Pyramidal Dome Geometry on the Acoustical Characteristics in A Mosque

Directory of Open Access Journals (Sweden)

Dg. H. Kassim

2014-12-01

Full Text Available As an important symbol in Islam, a mosque is built with architectural grandeur. Among the characteristics is its high ceiling and it is usually constructed with a typical spherical dome shape. Some mosques, however, are influenced by the local culture and the dome can be of a different shape, such as pyramidal, as found in mosques in Malacca, Malaysia. This paper presents an assessment of the internal acoustical characteristics of a mosque having a pyramidal dome. The study is conducted by means of computer simulation using CATT indoor acoustic software. Reverberation time and clarity are taken to evaluate the intelligibility of speech. The effect of the angle and height of the dome on the acoustical parameters is discussed. It is found that a pyramidal dome with a steeper angle contributes to poor acoustic clarity.

Draft environmental assessment: Vacherie Dome site, Louisiana. Nuclear Waste Policy Act (Section 112)

International Nuclear Information System (INIS)

1984-12-01

In February 1983, the US Department of Energy (DOE) identified the Vacherie dome in Louisiana as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Vacherie dome site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for Nuclear Waste Repositories. These evaluations are reported in this draft environmental assessment (EA), which is being issued for public review and comment. The DOE findings and determinations that are based on these evaluations are preliminary and subject to public review and comment. A final EA will be prepared after considering the comments received. On the basis of the evaluations contained in this draft EA, the DOE has found that the Vacherie dome site is not disqualified under the guidelines. The site is contained in the Gulf Interior Region of the Gulf Coastal Plain, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains two other potentially acceptable sites - the Cypress Creek dome site and the Richton dome site. Although the Vacherie dome site appears to be suitable for site characterization, the DOE has concluded that the Richton dome site is the preferred site in the Gulf Interior Region. On the basis of these findings, the DOE is proposing to nominate the Richton dome site rather than the Vacherie dome site as one of the five sites suitable for characterization

Profiled Roller Stress/Fatigue Life Analysis Methodology and Establishment of an Appropriate Stress/Life Exponent

Science.gov (United States)

1997-01-01

The objective of this work was to determine the three dimensional volumetric stress field, surface pressure distribution and actual contact area between a 0.50" square roller with different crown profiles and a flat raceway surface using Finite Element Analysis. The 3-dimensional stress field data was used in conjunction with several bearing fatigue life theories to extract appropriate values for stress-life exponents. Also, results of the FEA runs were used to evaluate the laminated roller model presently used for stress and life prediction.

A Optimal Dimension Parameters Design of Needle Roller Bearings Considering Multi Factors Affecting Life

Science.gov (United States)

Bai, XiaoBo; Li, Bo

2017-12-01

Taking into many influencing factors, a Needle Roller Bearings life calculation model was established using the Influence coefficient method and ISO formula. Take this model as the optimization objective function, some optimization variables were determined, and these variables were added constraint conditions. Using dynamic nonlinear strategy to improve the inertia weight, the arccosine strategy to adjust the learning factor, function constraints was solved by the methods of ensure particle legitimacy. Nonlinear optimization design of cylindrical roller bearings was realized by Improved Particle Swarm Algorithm. The proposed method of bearing design was verified effective by test of the optimization results.

A history of semi-active laser dome and window materials

Science.gov (United States)

Sullivan, Roger M.

2014-05-01

Semi-Active Laser (SAL) guidance systems were developed starting in the mid-1960's and today form an important class of precision guided weapons. The laser wavelengths generally fall in the short wave infrared region of the spectrum. Relative to passive, image based, infrared seekers the optical demands placed on the domes or windows of SAL seekers is very modest, allowing the use of low cost, easily manufactured materials, such as polycarbonate. This paper will examine the transition of SAL window and dome science and technology from the laboratory to battlefield, with special emphasis on the story of polycarbonate domes.

Mud dome, stone dome and mud and stone dome in the rural buildings of vernacular architecture in center of Castilla y León (Spain

Directory of Open Access Journals (Sweden)

O. Abril Revuelta

2017-06-01

Full Text Available In the center of Castilla y León there are few examples of old rural buildings linked to economic activities that have developed in the agrarian field. These are known chozos and casetas, and they have been built with dome-shaped solutions using autochthon materials: mud and stone. The influence of traditional techniques of both elements has generated a singular typological rarely seen in the rest of the Iberian Peninsula. Different types of domes have been analyzed in situ. And they have been contrasted by documentary sources and it has significantly expanded the information published of them, especially about their typological variety and their construction process. This research aims to provide tools to restore a constructive knowledge that is forgotten in place, to value its architectural wealth, which can encourage their rehabilitation.

Dome-shaped PDC cutters drill harder rock effectively

International Nuclear Information System (INIS)

Moran, D.P.

1992-01-01

This paper reports that rock mechanics and sonic travel time log data indicate that bits with convex-shaped polycrystalline diamond compact (PDC) cutters can drill harder rock formations than comparable bits with flat PDC cutters. The Dome-shaped cutters have drilled carbonate formations with sonic travel times as small as 50 μsec/ft, compared to the standard cutoff of 75 μsec/ft for flat PCD cutters. Recent field data from slim hole wells drilled in the Permian basin have shown successful applications of the 3/8-in. Dome cutter in the Grayburg dolomite with its sonic travel times as low as 50-55 μsec/ft and compressive strengths significantly greater than the standard operating range for PDC bit applications. These field data indicate that the Dome cutters can successfully drill hard rock. The convex cutter shape as good impact resistance, cuttings removal, heat dissipation, and wear resistance

The Development of M Cells in Peyer’s Patches Is Restricted to Specialized Dome-Associated Crypts

Science.gov (United States)

Gebert, Andreas; Fassbender, Susanne; Werner, Kerstin; Weissferdt, Annikka

1999-01-01

It is controversial whether the membranous (M) cells of the Peyer’s patches represent a separate cell line or develop from enterocytes under the influence of lymphocytes on the domes. To answer this question, the crypts that produce the dome epithelial cells were studied and the distribution of M cells over the domes was determined in mice. The Ulex europaeus agglutinin was used to detect M cells in mouse Peyer’s patches. Confocal microscopy with lectin-gold labeling on ultrathin sections, scanning electron microscopy, and laminin immuno-histochemistry were combined to characterize the cellular composition and the structure of the dome-associated crypts and the dome epithelium. In addition, the sites of lymphocyte invasion into the dome epithelium were studied after removal of the epithelium using scanning electron microscopy. The domes of Peyer’s patches were supplied with epithelial cells that derived from two types of crypt: specialized dome-associated crypts and ordinary crypts differing not only in shape, size, and cellular composition but also in the presence of M cell precursors. When epithelial cells derived from ordinary crypts entered the domes, they formed converging radial strips devoid of M cells. In contrast to the M cells, the sites where lymphocytes invaded the dome epithelium were not arranged in radial strips, but randomly distributed over the domes. M cell development is restricted to specialized dome-associated crypts. Only dome epithelial cells that derive from these specialized crypts differentiate into M cells. It is concluded that M cells represent a separate cell line that is induced in the dome-associated crypts by still unknown, probably diffusible lymphoid factors. PMID:10329609

A Planetarium Inside Your Office: Virtual Reality in the Dome Production Pipeline

Science.gov (United States)

Summers, Frank

2018-01-01

Producing astronomy visualization sequences for a planetarium without ready access to a dome is a distorted geometric challenge. Fortunately, one can now use virtual reality (VR) to simulate a dome environment without ever leaving one's office chair. The VR dome experience has proven to be a more than suitable pre-visualization method that requires only modest amounts of processing beyond the standard production pipeline. It also provides a crucial testbed for identifying, testing, and fixing the visual constraints and artifacts that arise in a spherical presentation environment. Topics adreesed here will include rendering, geometric projection, movie encoding, software playback, and hardware setup for a virtual dome using VR headsets.

Seismic-refraction survey to the top of salt in the north end of the Salt Valley Anticline, Grand County, Utah

Science.gov (United States)

Ackermann, Hans D.

1979-01-01

A seismic-refraction survey, consisting of three lines about 2700, 2760, and 5460 meters long, was made at the north end of the Salt Valley anticline of the Paradox Basin in eastern Utah. The target was the crest of a diapiric salt mass and the overlying, deformed caprock. The interpretations reveal an undulating salt surface with as much as 80 meters of relief. The minimum depth of about 165 meters is near the location of three holes drilled by the U.S. Department of Energy for the purpose of evaluating the Salt Valley anticline as a potential site for radioactive waste storages Caprock properties were difficult to estimate because the contorted nature of these beds invalidated a geologic interpretation in terms of velocity layers. However, laterally varying velocities of the critically refracted rays throughout the area suggest differences in the gross physical properties of the caprock.

Seismic-refraction survey to the top of salt in the north end of the Salt valley anticline, Grand County, Utah

International Nuclear Information System (INIS)

Achermann, H.D.

1979-01-01

A sesimic-refraction survey, consisting of three lines about 2700, 2760, and 5460 meters long, was made at the north end of the Salt valley anticline of the Paradox Basin in eastern Utah. The target was the crest of a diapiric salt mass and the overlying, deformed caprock. The interpretations reveal an undulating salt surface with as much as 80 meters of relief. The minimum depth of about 165 meters is near the location of three holes drilled by the US Department of Energy for the purpose of evaluating the Salt Valley anticline as a potential site for radioactive waste storage. Caprock properties were difficult to estimate because the contorted nature of these beds invalidated a goelogic interpretation in terms of velocity layers. However, laterally varying velocities of the critically refracted rays throughout the area suggest differences in the gross physical properties of the caprock

Development of the armoring technique for ITER Divertor Dome

Energy Technology Data Exchange (ETDEWEB)

Litunovsky, Nikolay, E-mail: nlitunovsky@sintez.niiefa.spb.su [D.V. Efremov Reseasch Institute, 3, Doroga na Metallostroy, Saint Petersburg (Russian Federation); Alekseenko, Evgeny; Makhankov, Alexey; Mazul, Igor [D.V. Efremov Reseasch Institute, 3, Doroga na Metallostroy, Saint Petersburg (Russian Federation)

2011-10-15

This paper describes the current status of the technique for armoring of Plasma Facing Units (PFUs) of the ITER Divertor Dome with flat tungsten tiles planned for application at the procurement stage. Application of high-temperature vacuum brazing for armoring of High Heat Flux (HHF) plasma facing components was traditionally developed at the Efremov Institute and successfully tried out at the ITER R and D stage by manufacturing and HHF testing of a number of W- and Be-armored mock-ups . Nevertheless, the so-called 'fast brazing' technique successfully applied in the past was abandoned at the stage of manufacturing of the Dome Qualification Prototypes (Dome QPs), as it failed to retain the mechanical properties of CuCrZr heat sink of the substrate. Another problem was a substantially increased number of armoring tiles brazed onto one substrate. Severe ITER requirements for the joints quality have forced us to refuse from production of W/Cu joints by brazing in favor of casting. These modifications have allowed us to produce ITER Divertor Dome QPs with high-quality tungsten armor, which then passed successfully the HHF testing. Further preparation to the procurement stage is in progress.

Metallogenetic modeling for uranium exploration in rocks of the Abaira-Jussiape Anticlinal nucleus, Chapada Diamantina, Bahia; Modelagem metalogenetica para prospeccao de uranio nas rochas do nucleo da Anticlinal Abaira-Jussiape, Chapada Diamantina, Bahia

Energy Technology Data Exchange (ETDEWEB)

Santana, Jocilene dos Santos; Cruz, Simone Cerqueira Pereira; Barbosa, Johildo Salomao Figueiredo [Universidade Federal da Bahia (PPGG/UFBA), Salvador, BA (Brazil); Abram, Maisa Bastos; Martins, Adriano Alberto Marques, E-mail: jocilenesanttana@yahoo.com.br, E-mail: simonecruzufba@gmail.com, E-mail: johildo@cpgg.ufba.br, E-mail: maisa.abram@cprm.gov.br, E-mail: adriano1952@gmail.com [Companhia de Pesquisas de Recursos Minerais (CPRM), Salvador, BA (Brazil). Superintendencia Regional de Salvador. Servico Geologico do Brasil

2011-06-15

The NNW-SSE-trending Abaira-Jussiape Anticlinal is an antiformal culmination of folding and shearing in the Paramirim Corridor of the Western Chapada Diamantina. In its core paleoproterozoic, mylonitized Caraguatai Suite, tonalites-granodiorites, alkali-feldspar granites, syenites to quartz-syenites and Jussiape Suite granites crop out. Compressional and distensional stresses mark the structural geology of the area. The compressional structures are related to two distinct deformation phases, named D1a and D1b. The main compressional phase is ductile D1a, which is related to the nucleation of dextral to dextral-reverse shearing zones. Deformation and syn-D1a recrystallization involving plagioclase and the K-feldspar suggest deformation temperature conditions above 550 deg C. The following phase D2 is of ductilebrittle nature and culminates in reverse shearing zones. The distensional structures correspond to the D3 phase and are represented by frontal shear zones with normal movement. The petrographic study helped identify a pre-D1a hydrothermal alteration process related to albitization and potassification, syn-D1 oxidation process, and hydration and saussuritization related to phases D2 and D3. The integration of lithological, petrographic, structural and geophysical data by means of the logic Fuzzy, plus the existing information regarding structural and lithologic controls of the known uranium mineralization in the Paramirim Corridor, led us to identify two promising areas for radioactive element exploration in the nucleus of Abaira-Jussiape Anticlinal. (author)

Intelligence diagnosis method for roller bearings using features of AE signal

International Nuclear Information System (INIS)

Pan, J; Wang, H Q; Wang, F; Yang, J F; Liu, W B

2012-01-01

Rolling bearings are important components in rotating machines, which are wildly used in industrial production. The fault diagnosis technology plays a very important role for quality and life of machines. Based on symptom parameters of acoustic emission (AE) signals, this paper presents an intelligent diagnosis method for roller bearings using the principal component analysis, rough sets, and BP neural network to detect faults and distinguish fault types. The principal component analysis and the rough sets algorithm are used to reduce details of time-domain symptom parameters for training the BP neural network. The BP neural network, which is used for condition diagnosis of roller bearings, can obtain good convergence using the symptom parameters acquired by the principal component analysis and the rough sets during learning, and automatically distinguish fault types during diagnosing. Practical examples are provided to verify the efficiency of the proposed method.

A roller-like bird (Coracii) from the Early Eocene of Denmark.

Science.gov (United States)

Bourdon, Estelle; Kristoffersen, Anette V; Bonde, Niels

2016-09-27

The fossil record of crown group birds (Neornithes) prior to the Cretaceous-Paleogene boundary is scarce and fragmentary. Early Cenozoic bird fossils are more abundant, but are typically disarticulated and/or flattened. Here we report the oldest roller (Coracii), Septencoracias morsensis gen. et sp. nov. (Primobucconidae), based on a new specimen from the Early Eocene (about 54 million years ago) Fur Formation of Denmark. The new fossil is a nearly complete, three-dimensionally preserved and articulated skeleton. It lies at the lower end of the size range for extant rollers. Salient diagnostic features of Septencoracias relative to other Coracii include the proportionally larger skull and the small, ovoid and dorsally positioned narial openings. Our discovery adds to the evidence that the Coracii had a widespread northern hemisphere distribution in the Eocene. Septencoracias is the oldest substantial record of the Picocoraciae and provides a reliable calibration point for molecular phylogenetic studies.

Predictions of Aerodynamic Heating on Tactical Missile Domes

Science.gov (United States)

1979-04-25

A . Martellucci W. Daskin J. D. Cresswell J. B. Arnaiz L. A . Marshall J. Cassanto R. Hobbs C. Harris F. George P.O. Box 8555 Philadelphia, PA J9101... A LEVELs NSWC TR 79-21 i PREDICTIONS OF AERODYNAMIC HEATING ON TACTICAL MISSILE DOMES A wo BY T. F. ZIEN W. C. RAGSDALE RESEARCH TECHNOLOGY...DOMES SAUTHOR( a ) 8. CONTRACT OR GRANT NUMBER() T. F. ZiendW.C jRagsale 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT. TASK

Full Dome Development for Interactive Immersive Training Capabilities

Science.gov (United States)

2015-04-03

called the the vDome Player. This application serves as a familiar user interface for direct media playback. Modeled after the widely used VLC ...charrette challenge to task. Below are my notes on where everyone is in planning thei r f inal proj ects . Please let me know (comments or emai l...space with a lot of sound and feeling. What is challenging ? The challenge is how to get depth of field in the dome. Trying to gently allure people into

Roller-coaster Ride to, Relief From TMJ | NIH MedlinePlus the Magazine

Science.gov (United States)

... on a roller coaster ride, seeking relief from temporomandibular joint (TMJ) disorder, which causes pain and, sometimes, dysfunction in the jaw joint and muscles of the neck, head, and face. She has endured: excruciating pain ...

Jurassic domes in the North Sea - northern North Atlantic region

Energy Technology Data Exchange (ETDEWEB)

Surlyk, F. [Univ. of Copenhagen, Geological Inst., Copenhagen (Denmark)

1996-12-31

The stratigraphic and tectonic evolution of the Jurassic of East Greenland, the Norwegian Shelf and the North Sea is remarkably similar. A major Middle Jurassic unconformity occurs in all three areas. In the North Sea it is commonly termed the `Mid-Cimmerian Unconformity` and is characterized by progressive truncation of the underlying section towards a centre at the triple junction between the Central Graben, Viking Graben and Moray Firth. Strata above the unconformity show a progressive Late Aalenian-Early Kimmeridgian onlap in the same direction. These relations have been interpreted as caused by Early Jurassic uplift and of a major thermal dome in the central North Sea, followed by Medial and Late Jurassic rifting, erosion, deflation and transgression of the dome. The East Greenland unconformity shows progressive truncation of underlying strata from south to north, and Bajocian to Callovian onlap in the same direction. The same pattern seems to be developed on the conjugate Norwegian margin. This suggests the possibility that the three unconformities have similar causes for their development. It is proposed that major rift domes formed in the Central North Sea and in the Greenland-Norway seaway in Early Jurassic times. The domes were eroded and gradually deflated during Medial Jurassic times and were finally submerged by the Late Oxfordian-Kimmeridgian. They were associated with volcanism and rifting which was delayed with respect to dome initiation. Roughly contemperaneous domes were present west of Britain, north of the Porcupine Seabight, and in Scania, southern Sweden, as reflected by development of asymmetrical unconformities showing progressive truncation of underlying strata, onlap of overlying Jurassic strata, and associated intrusive and extrusive volcanism. The domes are related to impingement of the heads of transient mantle plumes at the base of the lithosphere. The associated unconformities are thus of non-eustatic nature. Domal uplift and

Conceptual model for regional radionuclide transport from a salt dome repository: a technical memorandum

International Nuclear Information System (INIS)

Kier, R.S.; Showalter, P.A.; Dettinger, M.D.

1980-01-01

Disposal of high-level radioactive wastes is a major environmental problem influencing further development of nuclear energy in this country. Salt domes in the Gulf Coast Basin are being investigated as repository sites. A major concern is geologic and hydrologic stability of candidate domes and potential transport of radionuclides by groundwater to the biosphere prior to their degradation to harmless levels of activity. This report conceptualizes a regional geohydrologic model for transport of radionuclides from a salt dome repository. The model considers transport pathways and the physical and chemical changes that would occur through time prior to the radionuclides reaching the biosphere. Necessary, but unknown inputs to the regional model involve entry and movement of fluids through the repository dome and across the dome-country rock interface and the effect on the dome and surrounding strata of heat generated by the radioactive wastes

Fire ants protect mealybugs against their natural enemies by utilizing the leaf shelters constructed by the leaf roller Sylepta derogata.

Directory of Open Access Journals (Sweden)

Aiming Zhou

Full Text Available The importance of mutualism is receiving more attention in community ecology. In this study, the fire ant Solenopsis invicta was found to take advantage of the shelters constructed by the leaf roller Sylepta derogata to protect mealybugs (Phenacoccus solenopsis against their natural enemies. This protective effect of fire ant tending on the survival of mealybugs in shelters was observed when enemies and leaf rollers were simultaneously present. Specifically, fire ants moved the mealybugs inside the shelters produced by S. derogata on enemy-infested plants. Compared with that in plants without ants, the survival of mealybugs in shelters in the presence of natural enemies in plants with ants markedly improved. Both the protection of ants and the shelters provided by leaf rollers did not affect the survival of mealybugs in the absence of enemies in plants. Ants and leaf rollers significantly improved the survival of mealybugs in predator-infested plants, whereas no such improvement was observed in parasitoid-infested ones.

On Calculation Methods and Results for Straight Cylindrical Roller Bearing Deflection, Stiffness, and Stress

Science.gov (United States)

Krantz, Timothy L.

2011-01-01

The purpose of this study was to assess some calculation methods for quantifying the relationships of bearing geometry, material properties, load, deflection, stiffness, and stress. The scope of the work was limited to two-dimensional modeling of straight cylindrical roller bearings. Preparations for studies of dynamic response of bearings with damaged surfaces motivated this work. Studies were selected to exercise and build confidence in the numerical tools. Three calculation methods were used in this work. Two of the methods were numerical solutions of the Hertz contact approach. The third method used was a combined finite element surface integral method. Example calculations were done for a single roller loaded between an inner and outer raceway for code verification. Next, a bearing with 13 rollers and all-steel construction was used as an example to do additional code verification, including an assessment of the leading order of accuracy of the finite element and surface integral method. Results from that study show that the method is at least first-order accurate. Those results also show that the contact grid refinement has a more significant influence on precision as compared to the finite element grid refinement. To explore the influence of material properties, the 13-roller bearing was modeled as made from Nitinol 60, a material with very different properties from steel and showing some potential for bearing applications. The codes were exercised to compare contact areas and stress levels for steel and Nitinol 60 bearings operating at equivalent power density. As a step toward modeling the dynamic response of bearings having surface damage, static analyses were completed to simulate a bearing with a spall or similar damage.

SOLUTION MINING IN SALT DOMES OF THE GULF COAST EMBAYMENT

Energy Technology Data Exchange (ETDEWEB)

Griswold, G. B.

1981-02-01

Following a description of salt resources in the salt domes of the gulf coast embayment, mining, particularly solution mining, is described. A scenario is constructed which could lead to release of radioactive waste stored in a salt dome via inadvertent solution mining and the consequences of this scenario are analyzed.

Roller skating--is it a dangerous sport?

Science.gov (United States)

Tse, P Y; Shen, W Y; Chan, K M; Leung, P C

1987-01-01

A prospective survey of 111 cases of roller skating injuries within one year are reported. Males were more commonly injured than females. There was a high incidence (86%) of serious injuries, 28% of which required surgical treatment. The wrist (23%) was the commonest region involved, followed by the shoulder (20%), the elbow (15%) and the ankle (12%). Collision with other skaters and loss of control were the main factors leading to injury. Better rink discipline, instruction classes and safety publicity should be helpful in minimising accidents. Images Fig. 2 & Fig. 3 PMID:3676638

Intermittent stick-slip dynamics during the peeling of an adhesive tape from a roller.

Science.gov (United States)

Cortet, Pierre-Philippe; Dalbe, Marie-Julie; Guerra, Claudia; Cohen, Caroline; Ciccotti, Matteo; Santucci, Stéphane; Vanel, Loïc

2013-02-01

We study experimentally the fracture dynamics during the peeling at a constant velocity of a roller adhesive tape mounted on a freely rotating pulley. Thanks to a high speed camera, we measure, in an intermediate range of peeling velocities, high frequency oscillations between phases of slow and rapid propagation of the peeling fracture. This so-called stick-slip regime is well known as the consequence of a decreasing fracture energy of the adhesive in a certain range of peeling velocity coupled to the elasticity of the peeled tape. Simultaneously with stick slip, we observe low frequency oscillations of the adhesive roller angular velocity which are the consequence of a pendular instability of the roller submitted to the peeling force. The stick-slip dynamics is shown to become intermittent due to these slow pendular oscillations which produce a quasistatic oscillation of the peeling angle while keeping constant the peeling fracture velocity (averaged over each stick-slip cycle). The observed correlation between the mean peeling angle and the stick-slip amplitude questions the validity of the usually admitted independence with the peeling angle of the fracture energy of adhesives.

Draft environmental assessment: Richton Dome site, Mississippi. Nuclear Waste Policy Act (Section 112)

International Nuclear Information System (INIS)

1984-12-01

In February 1983, the US Department of Energy identified the Richton dome site as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Richton dome site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for Nuclear Waste Repositories. These evaluations are reported in this draft (EA), which is being issued for public review and comment. The DOE findings and determinations that are based on these evaluations are preliminary and subject to public review and comment. A final EA will be prepared after considering the comments received. On the basis of the evaluations reported in this draft EA, the DOE has found that the Richton dome site is not disqualified under the guidelines. The site is in the Gulf Interior Region of the Gulf Coastal Plain. This setting contains two other potentially acceptable sites - the Cypress Creek dome site and the Vacherie dome site. Although these other two sites appear to be suitable for site characterization, the DOE has concluded that the Richton dome site is the preferred site in the Gulf Interior Region. Furthermore, the DOE finds that the site is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is proposing to nominate the Richton dome site as one of five sites suitable for characterization. Having compared the Richton dome site with the other four sites proposed for nomination, the DOE has determined that the Richton dome site is not one of the three preferred sites for recommendation to the President as candidates for characterization

Forces and dynamics in epithelial domes of controlled size and shape

Science.gov (United States)

Latorre-Ibars, Ernest; Casares, Laura; Gomez-Gonzalez, Manuel; Uroz, Marina; Arroyo, Marino; Trepat, Xavier

Mechanobiology of epithelia plays a central role in morphogenesis, wound healing, and tumor progression. Its current understanding relies on mechanical measurements on flat epithelial layers. However, most epithelia in vivo exhibit a curved 3D shape enclosing a pressurized lumen. Using soft micropatterned substrates we produce massive parallel arrays of epithelial domes with controlled size and basal shape. We measure epithelial traction, tension, and luminal pressure in epithelial domes. The local stress tensor on the freestanding epithelial membrane is then mapped by combining measured luminal pressure and local curvature. We show that tension and cell shape are highly anisotropic and vary along the meridional position of the domes. Finally, we establish constitutive relations between shape, tension, and pressure during perturbations of the contractile machinery, osmotic shocks, and spontaneous fluctuations of dome volume. Our findings contradict a description of the epithelium as a fluid capillary surface. Cells in the dome are unable to relax into a uniform and isotropic tensional state through sub- and supra-cellular rearrangements. Mapping epithelial shape, tension, and pressure will enable quantitative studies of mechanobiology in 3D epithelia of controlled size and shape.

Uplift rates of marine terraces as a constraint on fault-propagation fold kinematics: Examples from the Hawkswood and Kate anticlines, North Canterbury, New Zealand

Science.gov (United States)

Oakley, David O. S.; Fisher, Donald M.; Gardner, Thomas W.; Stewart, Mary Kate

2018-01-01

Marine terraces on growing fault-propagation folds provide valuable insight into the relationship between fold kinematics and uplift rates, providing a means to distinguish among otherwise non-unique kinematic model solutions. Here, we investigate this relationship at two locations in North Canterbury, New Zealand: the Kate anticline and Haumuri Bluff, at the northern end of the Hawkswood anticline. At both locations, we calculate uplift rates of previously dated marine terraces, using DGPS surveys to estimate terrace inner edge elevations. We then use Markov chain Monte Carlo methods to fit fault-propagation fold kinematic models to structural geologic data, and we incorporate marine terrace uplift into the models as an additional constraint. At Haumuri Bluff, we find that marine terraces, when restored to originally horizontal surfaces, can help to eliminate certain trishear models that would fit the geologic data alone. At Kate anticline, we compare uplift rates at different structural positions and find that the spatial pattern of uplift rates is more consistent with trishear than with a parallel-fault propagation fold kink-band model. Finally, we use our model results to compute new estimates for fault slip rates ( 1-2 m/ka at Kate anticline and 1-4 m/ka at Haumuri Bluff) and ages of the folds ( 1 Ma), which are consistent with previous estimates for the onset of folding in this region. These results are consistent with previous work on the age of onset of folding in this region, provide revised estimates of fault slip rates necessary to understand the seismic hazard posed by these faults, and demonstrate the value of incorporating marine terraces in inverse fold kinematic models as a means to distinguish among non-unique solutions.

Simulation of accelerated strip cooling on the hot rolling mill run-out roller table

Directory of Open Access Journals (Sweden)

E.Makarov

2016-07-01

Full Text Available A mathematical model of the thermal state of the metal in the run-out roller table continuous wide hot strip mill. The mathematical model takes into account heat generation due to the polymorphic γ → α transformation of supercooled austenite phase state and the influence of the chemical composition of the steel on the physical properties of the metal. The model allows calculation of modes of accelerated cooling strips on run-out roller table continuous wide hot strip mill. Winding temperature calculation error does not exceed 20°C for 98.5 % of strips of low-carbon and low-alloy steels

Roller kiln with very low fluoride emission. The Ecokiln

Energy Technology Data Exchange (ETDEWEB)

Reymer, P.S.; Denissen, A.M. [TNO TPD Materials Research and Technology, Eindhoven (Netherlands)

2001-09-01

In most European countries the limit for fluoride emission in ceramic kiln flue gases is set at 5 mg HF/m{sup 3} flue gas. In cooperation with Royal Mosa, Royal Sphinx, Gasunie in the Netherlands and Sacmi, Italy, a roller kiln has been developed which can operate below the fore-mentioned limit. Also, a flue gas cleaning device is not necessary. 4 refs.

MROI Array telescopes: the relocatable enclosure domes

Science.gov (United States)

Marchiori, G.; Busatta, A.; Payne, I.

2016-07-01

The MROI - Magdalena Ridge Interferometer is a project which comprises an array of up to 10 1.4m diameter mirror telescopes arranged in a "Y" configuration. Each of these telescopes will be housed inside a Unit Telescope Enclosure (UTE) which are relocatable onto any of 28 stations. EIE GROUP Srl, Venice - Italy, was awarded the contract for the design, the construction and the erection on site of the MROI by the New Mexico Institute of Mining and Technology. The close-pack array of the MROI - including all 10 telescopes, several of which are at a relative distance of less than 8m center to center from each other - necessitated an original design for the Unit Telescope Enclosure (UTE). This innovative design enclosure incorporates a unique dome/observing aperture system to be able to operate in the harsh environmental conditions encountered at an altitude of 10,460ft (3,188m). The main characteristics of this Relocatable Enclosure Dome are: a Light insulated Steel Structure with a dome made of composites materials (e.g. glass/carbon fibers, sandwich panels etc.), an aperture motorized system for observation, a series of louvers for ventilation, a series of electrical and plants installations and relevant auxiliary equipment. The first Enclosure Dome is now under construction and the completion of the mounting on site id envisaged by the end of 2016. The relocation system utilizes a modified reachstacker (a transporter used to handle freight containers) capable of maneuvering between and around the enclosures, capable of lifting the combined weight of the enclosure with the telescope (30tons), with minimal impacts due to vibrations.

Simulation modeling of wheeled vehicle dynamics on the stand "Roller"

Directory of Open Access Journals (Sweden)

G. O. Kotiev

2014-01-01

Full Text Available The tests are an integral part of the wheeled vehicle design, manufacturing, and operation. The need for their conducting arises from the research and experimental activities to assess the qualitative and quantitative characteristics of the vehicles in general, as well as the individual components and assemblies. It is obvious that a variety of design features of wheeled vehicles request a development of methods both for experimental studies and for creating the original bench equipment for these purposes.The main positive feature of bench tests of automotive engineering is a broad capability to control the combinations of traction loads, speed rates, and external input conditions. Here, the steady state conditions can be used for a long time, allowing all the necessary measurements to be made, including those with video and photo recording experiment.It is known that the benefits of test "M" type (using a roller dynamometer include a wide range of test modes, which do not depend on the climatic conditions, as well as a capability to use a computer-aided testing programs. At the same time, it is known that the main drawback of bench tests of full-size vehicle is that the tire rolling conditions on the drum mismatch to the real road pavements, which are difficult to simulate on the drum surface. This problem can be solved owing to wheeled vehicle tests at the benches "Roller" to be, in efficiency, the most preferable research method. The article gives a detailed presentation of developed at BMSTU approach to its solving.Problem of simulation mathematical modeling has been solved for the vehicle with the wheel formula 8 × 8, and individual wheel-drive.The simulation results have led to the conclusion that the proposed principle to simulate a vehicle rolling on a smooth non-deformable support base using a bench " Roller " by simulation modeling is efficient.

Seismicity associated with dome growth and collapse at the Soufriere Hills Volcano, Montserrat

Science.gov (United States)

Miller, A.D.; Stewart, R.C.; White, R.A.; Luckett, R.; Baptie, B.J.; Aspinall, W.P.; Latchman, J.L.; Lynch, L.L.; Voight, B.

1998-01-01

Varied seismicity has accompanied growth and collapse of the lava dome of the Soufriere Hills Volcano, Montserrat. Earthquakes have been classified as either volcano-tectonic, long-period or hybrid, and daily variations in the numbers of events have mapped changes in the style of eruption. Repetitive hybrid earthquakes were common during the first months of dome growth. In July 1996 the style of seismicity changed and regular short-lived hybrid earthquake swarms became common. This change was probably caused by an increase in the magma flux. Earthquake swarms have preceded almost all major dome collapses, and have accompanied cyclical deformation, thought to be due to a built-up of pressure in the upper conduit which is later released by magma moving into the dome.Varied seismicity has accompanied growth and collapse of the lava dome of the Soufriere Hills Volcano, Montserrat. Earthquakes have been classified as either volcano-tectonic, long-period or hybrid, and daily variations in the numbers of events have mapped changes in the style of eruption. Repetitive hybrid earthquakes were common during the first months of dome growth. In July 1996 the style of seismicity changed and regular, short-lived hybrid earthquake swarms became common. This change was probably caused by an increase in the magma flux. Earthquake swarms have preceded almost all major dome collapses, and have accompanied cyclical deformation, thought to be due to a build-up of pressure in the upper conduit which is later released by magma moving into the dome.

Draft environmental assessment: Cypress Creek Dome site, Mississippi. Nuclear Waste Policy Act (Section 112)

International Nuclear Information System (INIS)

1984-12-01

In February 1983, the US Department of Energy (DOE) identified the Cypress Creek dome site in Mississippi as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Cypress Creek dome site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for Nuclear Waste Repositories. These evaluations are reported in this draft environmental assessment (EA), which is being issued for public review and comment. The DOE findings and determinations that are based on these evaluations are preliminary and subject to public review and comment. A final EA will be prepared after considering the comments received. On the basis of the evaluations contained in this draft EA, the DOE has found that the Cypress Creek dome site is not disqualified under the guidelines. The site is contained in the Gulf Interior Region of the Gulf Coastal Plain, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains two other potentially acceptable sites - the Richton dome site and the Vacherie dome site. Although the Cypress Creek dome site appears to be suitable for site characterization, the DOE has concluded that the Richton dome site is the preferred site in the Gulf Interior Region and is proposing to nominate the Richton dome site rather than the Cypress Creek dome site as one of the three sites suitable for characterization

Longitudinal biases in the Seychelles Dome simulated by 35 ocean-atmosphere coupled general circulation models

Science.gov (United States)

Nagura, Motoki; Sasaki, Wataru; Tozuka, Tomoki; Luo, Jing-Jia; Behera, Swadhin K.; Yamagata, Toshio

2013-02-01

Seychelles Dome refers to the shallow climatological thermocline in the southwestern Indian Ocean, where ocean wave dynamics efficiently affect sea surface temperature, allowing sea surface temperature anomalies to be predicted up to 1-2 years in advance. Accurate reproduction of the dome by ocean-atmosphere coupled general circulation models (CGCMs) is essential for successful seasonal predictions in the Indian Ocean. This study examines the Seychelles Dome as simulated by 35 CGCMs, including models used in phase five of the Coupled Model Intercomparison Project (CMIP5). Among the 35 CGCMs, 14 models erroneously produce an upwelling dome in the eastern half of the basin whereas the observed Seychelles Dome is located in the southwestern tropical Indian Ocean. The annual mean Ekman pumping velocity in these models is found to be almost zero in the southern off-equatorial region. This result is inconsistent with observations, in which Ekman upwelling acts as the main cause of the Seychelles Dome. In the models reproducing an eastward-displaced dome, easterly biases are prominent along the equator in boreal summer and fall, which result in shallow thermocline biases along the Java and Sumatra coasts via Kelvin wave dynamics and a spurious upwelling dome in the region. Compared to the CMIP3 models, the CMIP5 models are even worse in simulating the dome longitudes.

Studies of the suitability of salt domes in east Texas basin for geologic isolation of nuclear wastes

International Nuclear Information System (INIS)

Kreitler, C.W.

1979-01-01

The suitability of salt domes in the east Texas basin (Tyler basin), Texas, for long-term isolation of nulear wastes is being evaluated. The major issues concern hydrogeologic and tectonic stability of the domes and potential natural resources in the basin. These issues are being approached by integration of dome-specific and regional hydrogeolgic, geologic, geomorphic, and remote-sensing investigations. Hydrogeologic studies are evaluating basinal hydrogeology and ground-water flow around the domes in order to determine the degree to which salt domes may be dissolving, their rates of solution, and the orientation of saline plumes in the fresh-water aquifers. Subsurface geologic studies are being conducted: (1) to determine the size and shape of specific salt domes, the geology of the strata immediately surrounding the domes, and the regional geology of the east Texas basin; (2) to understand the geologic history of dome growth and basin infilling; and (3) to evaluate potential natural resources. Geomorphic and surficial geology studies are determining whether there has been any dome growth or tectonic movement in the basin during the Quaternary. Remote-sensing studies are being conducted to determine: (1) if dome uplift has altered regional lineation patterns in Quaternary sediments; and (2) whether drainage density indicates Quaternary structural movement. On the basis of the screening criteria of Brunton et al (1978), Oakwood and Keechi domes have been chosen as possible candidate domes. Twenty-three domes have been eliminated because of insufficient size, too great a depth to salt, major hydrocarbon production, or previous use (such as liquid propane storage or salt mining or brining). Detailed geologic, hydrogeologic, and geomorphic investigations are now being conducted around Oakwood and Keechi salt domes

Determining the coordinates of lamps in an illumination dome

Science.gov (United States)

MacDonald, Lindsay W.; Ahmadabadian, Ali H.; Robson, Stuart

2015-05-01

The UCL Dome consists of an acrylic hemisphere of nominal diameter 1030 mm, fitted with 64 flash lights, arranged in three tiers of 16, one tier of 12, and one tier of 4 lights at approximately equal intervals. A Nikon D200 digital camera is mounted on a rigid steel frame at the `north pole' of the dome pointing vertically downwards with its optical axis normal to the horizontal baseboard in the `equatorial' plane. It is used to capture sets of images in pixel register for visualisation and surface reconstruction. Three techniques were employed for the geometric calibration of flash light positions in the dome: (1) the shadow cast by a vertical pin onto graph paper; (2) multi-image photogrammetry with retro-reflective targets; and (3) multi-image photogrammetry using the flash lights themselves as targets. The precision of the coordinates obtained by the three techniques was analysed, and it was found that although photogrammetric methods could locate individual targets to an accuracy of 20 μm, the uncertainty of locating the centroids of the flash lights was approximately 1.5 mm. This result was considered satisfactory for the purposes of using the dome for photometric imaging, and in particular for the visualisation of object surfaces by the polynomial texture mapping (PTM) technique.

Screw-released roller brake

Science.gov (United States)

Vranish, John M. (Inventor)

1999-01-01

A screw-released roller brake including an input drive assembly, an output drive assembly, a plurality of locking sprags, a mechanical tripper nut for unlocking the sprags, and a casing therefor. The sprags consist of three dimensional (3-D) sprag members having pairs of contact surface regions which engage respective pairs of contact surface regions included in angular grooves or slots formed in the casing and the output drive assembly. The sprags operate to lock the output drive assembly to the casing to prevent rotation thereof in an idle mode of operation. In a drive mode of operation, the tripper is either self actuated or motor driven and is translated linearly up and down against a spline and at the limit of its travel rotates the sprags which unlock while coupling the input drive assembly to the output drive assembly so as to impart a turning motion thereto in either a clockwise or counterclockwise direction.

Key variables influencing patterns of lava dome growth and collapse

Science.gov (United States)

Husain, T.; Elsworth, D.; Voight, B.; Mattioli, G. S.; Jansma, P. E.

2013-12-01

Lava domes are conical structures that grow by the infusion of viscous silicic or intermediate composition magma from a central volcanic conduit. Dome growth can be characterized by repeated cycles of growth punctuated by collapse, as the structure becomes oversized for its composite strength. Within these cycles, deformation ranges from slow long term deformation to sudden deep-seated collapses. Collapses may range from small raveling failures to voluminous and fast-moving pyroclastic flows with rapid and long-downslope-reach from the edifice. Infusion rate and magma rheology together with crystallization temperature and volatile content govern the spatial distribution of strength in the structure. Solidification, driven by degassing-induced crystallization of magma leads to the formation of a continuously evolving frictional talus as a hard outer shell. This shell encapsulates the cohesion-dominated soft ductile core. Here we explore the mechanics of lava dome growth and failure using a two-dimensional particle-dynamics model. This meshless model follows the natural evolution of a brittle carapace formed by loss of volatiles and rheological stiffening and avoids difficulties of hour-glassing and mesh-entangelment typical in meshed models. We test the fidelity of the model against existing experimental and observational models of lava dome growth. The particle-dynamics model follows the natural development of dome growth and collapse which is infeasible using simple analytical models. The model provides insight into the triggers that lead to the transition in collapse mechasnism from shallow flank collapse to deep seated sector collapse. Increase in material stiffness due to decrease in infusion rate results in the transition of growth pattern from endogenous to exogenous. The material stiffness and strength are strongly controlled by the magma infusion rate. Increase in infusion rate decreases the time available for degassing induced crystallization leading to a

Pre-HEAT: submillimeter site testing and astronomical spectra from Dome A, Antarctica

Science.gov (United States)

Kulesa, C. A.; Walker, C. K.; Schein, M.; Golish, D.; Tothill, N.; Siegel, P.; Weinreb, S.; Jones, G.; Bardin, J.; Jacobs, K.; Martin, C. L.; Storey, J.; Ashley, M.; Lawrence, J.; Luong-Van, D.; Everett, J.; Wang, L.; Feng, L.; Zhu, Z.; Yan, J.; Yang, J.; Zhang, X.-G.; Cui, X.; Yuan, X.; Hu, J.; Xu, Z.; Jiang, Z.; Yang, H.; Li, Y.; Sun, B.; Qin, W.; Shang, Z.

2008-07-01

Pre-HEAT is a 20 cm aperture submillimeter-wave telescope with a 660 GHz (450 micron) Schottky diode heterodyne receiver and digital FFT spectrometer for the Plateau Observatory (PLATO) developed by the University of New South Wales. In January 2008 it was deployed to Dome A, the summit of the Antarctic plateau, as part of a scientific traverse led by the Polar Research Institute of China and the Chinese Academy of Sciences. Dome A may be one of the best sites in the world for ground based Terahertz astronomy, based on the exceptionally cold, dry and stable conditions which prevail there. Pre-HEAT is measuring the 450 micron sky opacity at Dome A and mapping the Galactic Plane in the 13CO J=6-5 line, constituting the first submillimeter measurements from Dome A. It is field-testing many of the key technologies for its namesake -- a successor mission called HEAT: the High Elevation Antarctic Terahertz telescope. Exciting prospects for submillimeter astronomy from Dome A and the status of Pre-HEAT will be presented.

Water-quality data for aquifers, streams, and lakes in the vicinity of Keechi, Mount Sylvan, Oakwood, and Palestine salt domes, northeast Texas salt-dome basin

International Nuclear Information System (INIS)

Carr, J.E.; Halasz, S.J.; Liscum, F.

1980-11-01

This report contains water-quality data for aquifers, streams, and lakes in the vicinity of Keechi, Mount Sylvan, Oakwood, and Palestine Salt Domes in the northeast Texas salt-dome basin. Water-quality data were compiled for aquifers in the Wilcox Group, the Carrizo Sand, and the Queen City Sand. The data include analyses for dissolved solids, pH, temperature, hardness, calcium, magnesium, sodium, bicarbonate, chloride, and sulfate. Water-quality and streamflow data were obtained from 63 surface-water sites in the vicinity of the domes. These data include water discharge, specific conductance, pH, water temperature, and dissolved oxygen. Samples were collected at selected sites for analysis of principal and selected minor dissolved constituents

Usefulness of extracorporeal membrane oxygenation using double roller pumps in a low body weight newborn: A novel strategy for mechanical circulatory support in an infant

Directory of Open Access Journals (Sweden)

Keisuke Nakanishi

2016-01-01

Full Text Available Extracorporeal membrane oxygenation (ECMO with a centrifugal pump requires a certain flow rate; therefore, its application for low body weight infants is frequently accompanied by oxygenator membrane malfunction and/or inadequate perfusion. To prevent low-flow associated complications, we report a case in which a novel system of dual roller pumps was used. A baby girl with a body mass index 0.25 m 2 , who experienced difficulty weaning from cardiopulmonary bypass after a Norwood-like operation, required an ECMO. Concerns for the tube lifespan reduction due to roller pump friction led to the use of a double roller pump circulation. The termination of ECMO during tube exchange is not needed, because circulation is maintained by another roller pump. The novel strategy of ECMO with double roller pumps will allow low perfusion rate to provide adequate circulatory support for low body weight patients.

Ship detection in Sentinel-1 imagery using the h-dome transformation

CSIR Research Space (South Africa)

Schwegmann, CP

2015-07-01

Full Text Available is then processed to detect cluster centroids which indicate the ships’ positions. The following sections detail this procedure. 3.1. H-dome transform The H-dome transform is a method for finding local maxima, often used in the medical field for finding sub-cellular...) and comparing it to Fig. 2 (d) we no- tice that the brightest section of the ship can be seen much more clearly in (d). This is due to the property of the H- dome transform to highlight structures not typically visible (such as sub-cellular structures in [8...

Pin and roller attachment system for ceramic blades

Science.gov (United States)

Shaffer, J.E.

1995-07-25

In a turbine, a plurality of blades are attached to a turbine wheel by way of a plurality of joints which form a rolling contact between the blades and the turbine wheel. Each joint includes a pin and a pair of rollers to provide rolling contact between the pin and an adjacent pair of blades. Because of this rolling contact, high stress scuffing between the blades and the turbine wheel reduced, thereby inhibiting catastrophic failure of the blade joints. 3 figs.

Avoiding Electroerosion in roller bearings; Elektroerosion in Waelzlagern vermeiden

Energy Technology Data Exchange (ETDEWEB)

Preisinger, G.; Groeschl, M. [Inst. fuer Allgemeine Physik der TU Wien (Austria); Koettritsch, H. [SKF Oesterreich AG, Steyr (Austria)

2001-12-17

Roller bearings in electric motors and generators can be exposed to passage of current, which failes not only components, but also changes lubricants. The erosion can be avoided by isolation layers and optimized frequency converters. [German] Waelzlager in Elektromotoren und Generatoren koennen Stromdurchgang ausgesetzt sein, der nicht nur die Teile schaedigt, sondern auch den Schmierstoff veraendert. Die Schaeden sind nicht nur auf Metallteile begrenzt. Abhilfe bieten Isolationsschichten und optimierte Frequenzumrichter. (orig.)

Liikluseksperimendis edestas roller tsiklit ja teisi osalejaid : “2 vs 4″

Index Scriptorium Estoniae

2010-01-01

12. mail toimus Tallinnas keskkonnasõbraliku motonäituse MoMa raames eksperiment, milles osalesid jalgratas, elektriroller, roller, mootorratas ja auto. Marsruudil Miidurand-Nõmme üritati hommikuses liikluses välja selgitada, milline neist sõiduvahendest kõige edukamalt toime tuleb

Numerical estimates of the maximum sustainable pore pressure in anticline formations using the tensor based concept of pore pressure-stress coupling

Directory of Open Access Journals (Sweden)

Andreas Eckert

2015-02-01

Full Text Available The advanced tensor based concept of pore pressure-stress coupling is used to provide pre-injection analytical estimates of the maximum sustainable pore pressure change, ΔPc, for fluid injection scenarios into generic anticline geometries. The heterogeneous stress distribution for different prevailing stress regimes in combination with the Young's modulus (E contrast between the injection layer and the cap rock and the interbedding friction coefficient, μ, may result in large spatial and directional differences of ΔPc. A single value characterizing the cap rock as for horizontal layered injection scenarios is not obtained. It is observed that a higher Young's modulus in the cap rock and/or a weak mechanical coupling between layers amplifies the maximum and minimum ΔPc values in the valley and limb, respectively. These differences in ΔPc imposed by E and μ are further amplified by different stress regimes. The more compressional the stress regime is, the larger the differences between the maximum and minimum ΔPc values become. The results of this study show that, in general compressional stress regimes yield the largest magnitudes of ΔPc and extensional stress regimes provide the lowest values of ΔPc for anticline formations. Yet this conclusion has to be considered with care when folded anticline layers are characterized by flexural slip and the friction coefficient between layers is low, i.e. μ = 0.1. For such cases of weak mechanical coupling, ΔPc magnitudes may range from 0 MPa to 27 MPa, indicating imminent risk of fault reactivation in the cap rock.

Radiation observation at Dome Fuji Station, Antarctica

Directory of Open Access Journals (Sweden)

Naohiko Hirasawa

2008-06-01

Full Text Available This paper reports radiation observations at Dome Fuji Station from February 1, 2003 to January 20, 2004, carried out by the 44th Japanese Antarctic Research Expedition team. The radiometers which measured the upward longwave radiation (LWu, the downward longwave (LWd and the downward shortwave (SWd were equipped with fans to avoid frosting on the surface of the radiometer dome by air circulation. The upward shortwave radiation (SWu measured by a radiometer without fan needs correction, which we leave as a problem for the future. In addition, as for LWd and LWu in the polar night, a typical radiational cooling case and a suppressed radiational cooling one are shown.

Assessment of tectonic hazards to waste storage in interior-basin salt domes

International Nuclear Information System (INIS)

Kehle, R.

1979-01-01

Salt domes in the northern Gulf of Mexico may make ideal sites for storage of radioactive waste because the area is tectonically quiet. The stability of such salt domes and the tectonic activity are discussed

Roller and Centrifugal Pumps: A Retrospective Comparison of Bleeding Complications in Extracorporeal Membrane Oxygenation.

Science.gov (United States)

Halaweish, Ihab; Cole, Adam; Cooley, Elaine; Lynch, William R; Haft, Jonathan W

2015-01-01

Centrifugal pumps are increasingly used for extracorporeal membrane oxygenation (ECMO) rather than roller pumps. However, shear forces induced by these types of continuousflow pumps are associated with acquired von Willebrand factor deficiency and bleeding complications. This study was undertaken to compare adverse bleeding complications with the use of centrifugal and roller pumps in patients on prolonged ECMO support. The records of all adult ECMO patients from June 2002 to 2013 were retrospectively reviewed using the University of Michigan Health System database and the Extracorporeal Life Support Organization registry, focusing on patients supported for at least 5 days. Ninety-five ECMO patients met criteria for inclusion (48 roller vs. 47 centrifugal pump). Indications included pulmonary (79%), cardiac (15%), and extracorporeal cardiopulmonary resuscitation (6%), without significant difference between the two groups. Despite lower heparin anticoagulation (10.9 vs. 13.7 IU/kg/hr) with centrifugal pumps, there was a higher incidence of nonsurgical bleeding (gastrointestinal, pulmonary, and neurological) in centrifugal pump patients (26.1 vs. 9.0 events/1,000 patient-days, p = 0.024). In conclusion, in our historical comparison, despite reduced anticoagulation, ECMO support using centrifugal pumps was associated with a higher incidence of nonsurgical bleeding. The mechanisms behind this are multifactorial and require further investigation.

Analysis of tiltmeter monitoring of Northern Louisiana salt domes

International Nuclear Information System (INIS)

Waldon, M.G.; Thoms, R.L.

1983-01-01

Data were recorded at several tiltmeter sites in Northern Louisiana in the vicinity of Vacherie and Rayburn's salt domes. The objective of this data recording and subsequent analysis was to determine, if possible, the present rate of dome vertical movement, or to attempt to establish an upper bound to movement if undetectably small. Biaxial tiltmeters utilized were calibrated to detect extremely small tilts about two principal axes. No statistically significant tilting was observed during this survey. 13 references

Advanced imaging techniques III: a scalable and modular dome illumination system for scientific microphotography on a budget

Science.gov (United States)

A scalable and modular LED illumination dome for microscopic scientific photography is described and illustrated, and methods for constructing such a dome are detailed. Dome illumination for insect specimens has become standard practice across the field of insect systematics, but many dome designs ...

Visualizing asphalt roller trajectories in context: acquiring, processing, and representing sensor readings

NARCIS (Netherlands)

Vasenev, Alexandr

2015-01-01

The asphalt compaction process relies heavily on the skills and knowledge of roller operators who act alongside other stakeholders involved in asphalt paving. It is essential that these construction specialists: (1) are adequately informed about the initial temperature distribution of the asphalt

High Capacity cylinder roller bearing; High Capacity Zylinderrollenlager. Ein vollrolliges Lager mit Kaefig

Energy Technology Data Exchange (ETDEWEB)

Reichert, J.; Baum, J. [SKF, Schweinfurt (Germany)

2007-07-15

The high capacity cylinder roller bearing is an example for continuous development of SKF products and does an effective contribution to increase operational safety and offers the possibility to reduce weight and compact design. (GL)

Distributions of cranial pathologies provide evidence for head-butting in dome-headed dinosaurs (Pachycephalosauridae).

Science.gov (United States)

Peterson, Joseph E; Dischler, Collin; Longrich, Nicholas R

2013-01-01

Pachycephalosaurids are small, herbivorous dinosaurs with domed skulls formed by massive thickening of the cranial roof. The function of the dome has been a focus of debate: the dome has variously been interpreted as the product of sexual selection, as an adaptation for species recognition, or as a weapon employed in intraspecific combat, where it was used in butting matches as in extant ungulates. This last hypothesis is supported by the recent identification of cranial pathologies in pachycephalosaurids, which appear to represent infections resulting from trauma. However, the frequency and distribution of pathologies have not been studied in a systematic fashion. Here, we show that pachycephalosaurids are characterized by a remarkably high incidence of cranial injury, where 22% of specimens have lesions on the dome. Frequency of injury shows no significant difference between different genera, but flat-headed morphs (here interpreted as juveniles or females) lack lesions. Mapping of injuries onto a digitial pachycephalosaurid skull shows that although lesions are distributed across the dome, they cluster near the apex, which is consistent with the hypothesis that the dome functioned for intraspecific butting matches.

Instability behavior of stiffened dome liners under construction condition

International Nuclear Information System (INIS)

Jefts, A.R.; Guha-Majumdar, S.; Wanchoo, M.K.

1977-01-01

The purpose of this paper is to present techniques related to stability analysis, design concepts and behavior of dome liners. Various stiffening systems are examined from economy, schedule and constructablity point of view. The various failure modes can be classified as either buckling due to local instability or to an overall instability of the shell. Local instability may occur due to buckling of liner panel between a pair of rings and stringers or torsional and lateral buckling of the stiffeners. Methods are developed for proportioning stiffening system to preclude local buckling. Overall stability is a function of concrete pour height and thickness, loading distribution, time elapse between successive placements, rate of concrete placement, arrangement of stiffeners and other external supports. A computer program based on system energy minimization is used to study the overall instability of stiffened domes. Modelling techniques, effect of temperature and lack of bond, and their influence on results are discussed. Results for a self-standing stiffened hemispherical dome are presented in the form of mode shapes and buckling loads. Based on the results, a pouring scheme is recommended for an economical stiffening system. Recommendations are made to select the stiffening system and predict the buckling loads for preliminary analysis and design of the dome liner. Existing methods and code provisions related to tolerance, design criteria etc. are examined and recommendations made from practical considerations

Dome Structures Above Sills and Saucer-Shaped Sills: Insights From Experimental Modeling

Science.gov (United States)

Planke, S.; Galland, O.; Malthe-Sørenssen, A.

2007-12-01

Saucer-shaped magma and sand intrusions are common features in sedimentary basins. They result from fundamental processes for the emplacement of fluids in shallow sedimentary basins. Seismic data show that the overburden above saucer-shaped intrusions is usually deformed and exhibits a dome-like structure. The formation of such structures, and the associated deformation, are of primary importance in the evolution of petroleum systems. In this presentation, we report on experimental investigation of the deformation processes associated with the intrusion of saucer-shaped intrusions into sedimentary basins. The experimental setup consists of molten low-viscosity oil injected into fine-grained silica flour (see Galland et al., this session). It properly simulates the emplacement of saucer-shaped intrusions and the deformation of the country rock. During experiments, the surface of the model is digitalized through a structured light technique based on moiré projection principle. Such a tool provides topographic maps of the model and allows a periodic (every 1.5 s) monitoring of the model surface. When the model magma starts intruding, a symetrical dome rises above the inlet. As injection proceeds, the dome inflates and widens. Subsequently, the dome evolves to a plateau-like feature, with nearly flat surface and steep edges. The plateau keeps lifting up, but nearly stoppes widening. At the end of the experiments, the intruding liquid erupts at the edge of the plateau. The intrusion formed in the experiment is a typical saucer-shaped sill. The evolution of the deforming surface reflects the evolution of the intrusion. We infer that the first doming phase corresponds to the emplacement of a horizontal basal sill by open fracturing. The dome-to-plateau transition corresponds to a transition of the liquid emplacement mechanism from basal sill to inclined sheet. We suggest that the emplacement of the inclined sheets results from shear fracturing at the dome edge.

Kinematics of roller chain drives - Exact and approximate analysis

DEFF Research Database (Denmark)

Fuglede, Niels; Thomsen, Jon Juel

2016-01-01

An exact and approximate kinematic analysis of a roller chain drive modeled as a four-bar mechanism is presented. The span connects the sprockets such that they rotate in the same direction, and the sprocket size, number of teeth, and shaft center distance can be arbitrary. The driven sprocket...... to be very good agreement. All together this gives new insights into the characteristics of chain drive kinematics and the influence of main design parameters....

Electrical structure beneath the Hangai Dome, Mongolia, from magnetotelluric data

Science.gov (United States)

Comeau, Matthew; Käufl, Johannes; Becken, Michael; Kuvshinov, Alexey; Demberel, Sodnomsambuu; Sukhbaatar, Usnikh; Batmagnai, Erdenechimeg; Tserendug, Shoovdor; Nasan, Ochir

2017-04-01

The Hangai Dome in west-central Mongolia is an unusual high-elevation intra-continental plateau located far from tectonic plate boundaries and characterized by dispersed, low-volume, basaltic volcanism. This region is an ideal natural laboratory for studying intra-continental orogenic and magmatic processes resulting from crust-mantle interactions. The processes responsible for developing the Hangai Dome remain unexplained, due in part to a lack of high resolution geophysical data over the area. Here we present newly acquired broadband (0.008 - 3,000 s) magnetotelluric (MT) data from a large-scale ( 200 x 450 km) and high resolution (site spacing > 5 km) survey across the Hangai Dome. A total of 125 sites were collected and include full MT sites and telluric-only sites where inter-station transfer functions were computed. The MT data are used to generate an electrical resistivity model of the crust and upper mantle below the Hangai Dome. The model shows that the lower crust ( 30 - 50 km; below the brittle-ductile transition zone) beneath the Hangai Dome contains anomalous discrete pockets of low-resistivity ( 30 ohm-m) material that indicate the presence of local accumulations of fluids and/or low-percent partial melts. These anomalous regions appear to be spatially associated with the surface expressions of past volcanism, hydrothermal activity, and an increase in heat flow. They also correlate with observed crustal low-density and low-velocity anomalies. However they are in contrast to some geochemical and petrological studies which show long-lived crustal melt storage is impossible below the Hangai due to limited crustal assimilation and crustal contamination, arguing for a single parent-source at mantle depths. The upper mantle ( 6%) at this location. The results are consistent with modern geochemical and geophysical data, which show a thin lithosphere below the Hangai region. Furthermore the results agree with geodynamic models that require a low-heat flux

Roller Testing to Mimic Damage of the ISS SARJ Ring and Durability Test to Simulate Fifteen Years of SARJ Operation Using the Damaged Surface

Science.gov (United States)

Krantz, Timothy L.; Elchert, Justin P.; DellaCorte, Christopher; Dube, Michael J.

2016-01-01

The International Space Station's starboard Solar Alpha Rotary Joint (SARJ) experienced a breakdown of the joint's race ring surface. The starboard SARJ mechanism was cleaned and lubricated with grease. To provide some guidance on the expected behavior of the damaged SARJ ring with continued operations, experiments were conducted using rollers and a vacuum roller test rig. The approach of the experimental work involved three main steps: (1) initiate damage using conditions representative of the SARJ with inadequate lubrication; (2) propagate the damage by operating the test rollers without lubrication; and (3) assess the durability of the roller by testing to simulate the equivalent of 15 years of SARJ operation on the damaged surface assuming adequate grease lubrication. During the rig testing, additional and/or replacement grease was introduced at regular intervals to maintain good lubrication in the rig. The damage to the nitride layer continued even after application of grease. The grease lubrication proved to be effective for limiting the value of the axial force that can be developed. Limiting the axial force on the SARJ mechanism is important since the larger the axial force the more concentrated the load pressure becomes on the blend-radius location on the SARJ roller. After the testing simulating 15 years of SARJ operations, the wear depths were the order of 0.2 mm for the nitrided 15-5 roller and the order of 0.06 mm for the mating 440C roller. Metallographic inspections were done to search for indications of impending fatigue or other fracture indications that might eventually propagate and cause structural failure. There were no indications or features found that could eventually compromise structural integrity.

Sustainable Outreach: Lessons Learned from Space Update and Discovery Dome

Science.gov (United States)

Reiff, P. H.; Sumners, C.; Law, C. C.

2009-12-01

A sustainable program lives on past its initial funding cycle, and develops a network of users that ensures continued life, either by fees, advertising revenue, or by making the program more successful in later sponsored grants. Teachers like free things, so having a sponsor for products such as lithographs or CD-Roms is key to wide distribution. In 1994 we developed “Space Update®”, under the NASA “Public Use of the Internet” program. It has new editions annually, with over 40,000 distributed so far (many purchased but most free at teacher and student workshops). In 1996 we created a special edition “Space Weather®”, which includes the space weather module from Space Update plus other resources. Initially developed with funding from the IMAGE mission, it is now sponsored by Cluster and MMS. A new edition is published annually and distributed in the “Sun-Earth Day” packet; total distribution now exceeds 180,000. “Earth Update” was created in 1999 under cooperative agreement “Museums Teaching Planet Earth”. It now has a total distribution of over 20,000. Both Earth Update and Space Update were developed to be museum kiosk software, and more than 15 museums have them on display. Over 4,000 users are active in our e-Teacher network and 577 in our museum educator network. Although these can certainly be considered successful because of their longevity and user base, we have had a far more dramatic sustainable program arise in the last six years… the “Discovery Dome®”. Invented at HMNS and developed under NASA Cooperative Agreement “Immersive Earth”, this dome was the first digital portable planetarium that also showed fulldome movies with an interactive interface (first shown to the public at the Dec 2003 AGU meeting). The Discovery Dome network (tinyurl.com/DiscDome) has spun those initial 6 NASA-funded domes into over 90 installations in 22 states and 23 countries. Creating high quality content is quite expensive and so needs

Measurement of air quality within storage domes in technical area 54, areas G and L

International Nuclear Information System (INIS)

Anderson, E.

1994-01-01

The concentrations of volatile organic compounds (VOCs) and tritium inside of storage domes at TA-54 were measured to assess worker exposure and support the Area G site characterization, including the Radioactive Air Emissions Management (RAEM) program. Samples were collected at 2-3 locations within Domes 48, 49, and 153 on up to six days during the summer of 1994. Samples were collected to evaluate three scenarios: (1) normal working activities with the domes open; (2) after domes were closed overnight; and (3) after domes were closed for three days. Eight-hour integrated samples were collected and analyzed in Radian's Austin laboratories. Tritium activities from 17.1 to 69,900 pCi/m 3 were measured. About two dozen individual VOCs were identified in each sample, but most of the concentration levels were very low (e.g.; 20%) than when the domes were closed only overnight. The data were used to generate estimated annual dome emission rates of 0.3 Ci/yr of tritium and less than 100 lbs/yr of VOCs. The measured VOC concentrations were collected during the warmest months of the year and therefore should represent worst-case air impacts

Screening specifications for Gulf Coast salt domes

International Nuclear Information System (INIS)

Brunton, G.D.; Laughon, R.B.; McClain, W.C.

1978-01-01

A reconnaissance survey of the salt domes of Mississippi, Louisiana, and east Texas is being planned to identify study areas for potential sites for radioactive waste disposal. Preliminary screening specifications were derived for each of the geological evaluation criteria by application of the significant factors that will have an impact on the reconnaissance survey. The procedure for the derivation of each screening specification is discussed. The screening specifications are the official OWI values to be used for the first-cut acceptance for salt dome study areas along the Gulf Coast. The derivation of the screening specifications is illustrated by (1) a statement of the geological evaluation criterion, (2) a discussion of the pertinent factors affecting the criterion, and (3) the evaluation of the value of the specification

Stress and strain patterns, kinematics and deformation mechanisms in a basement-cored anticline: Sheep Mountain Anticline, Wyoming

Science.gov (United States)

Amrouch, Khalid; Lacombe, Olivier; Bellahsen, Nicolas; Daniel, Jean-Marc; Callot, Jean-Paul

2010-02-01

In order to characterize and compare the stress-strain record prior to, during, and just after folding at the macroscopic and the microscopic scales and to provide insights into stress levels sustained by folded rocks, we investigate the relationship between the stress-strain distribution in folded strata derived from fractures, striated microfaults, and calcite twins and the development of the Laramide, basement-cored Sheep Mountain Anticline, Wyoming. Tectonic data were mainly collected in Lower Carboniferous to Permian carbonates and sandstones. In both rock matrix and veins, calcite twins recorded three different tectonic stages: the first stage is a pre-Laramide (Sevier) layer-parallel shortening (LPS) parallel to fold axis, the second one is a Laramide LPS perpendicular to the fold axis, and the third stage corresponds to Laramide late fold tightening with compression also perpendicular to the fold axis. Stress and strain orientations and regimes at the microscale agree with the polyphase stress evolution revealed by populations of fractures and striated microfaults, testifying for the homogeneity of stress record at different scales through time. Calcite twin analysis additionally reveals significant variations of differential stress magnitudes between fold limbs. Our results especially point to an increase of differential stress magnitudes related to Laramide LPS from the backlimb to the forelimb of the fold possibly in relation with motion of an underlying basement thrust fault that likely induced stress concentrations at its upper tip. This result is confirmed by a simple numerical model. Beyond regional implications, this study highlights the potential of calcite twin analyses to yield a representative quantitative picture of stress and strain patterns related to folding.

Lake Robertson hydroelectric project. Construction of a roller compacted concrete dam

Energy Technology Data Exchange (ETDEWEB)

Labelle, M.; Robitaille, F. [Hydro-Quebec, Montreal, PQ (Canada)

1995-12-31

Construction of the Lake Robertson hydroelectric project on Quebec`s Lower North Shore was discussed in detail. The dam and powerhouse, located on the HaHa River, consists of a 134 m long concrete gravity dam, and a 21 MW powerhouse with two 69 kV transmission lines and four substations. The climate, terrain, and geography of the region, all of them characterized as severe, and the logistics of construction of the dam and power lines, aggravated by the isolation and severe conditions at the site, were described. The roller compacted concrete design and construction were noted, and justification for a concrete dam over an earth-fill dam was provided. Economics, properties, and composition of the roller compacted concrete (RCC) were examined, and control test results for the RCC concrete were provided. The use of RCC for the Lake Robertson development was described as successful in terms of the quality, watertightness, and completion time. The experience gained by the participants will make it possible to offer RCC as an alternative on various other projects. 2 figs.

Development, characteristics and comparative structural analysis of tensegrity type cable domes

Directory of Open Access Journals (Sweden)

Nenadović Aleksandra

2010-01-01

Full Text Available Tensegrity type cable domes are three-dimensional structural configurations, prestressed inside the perimeter compression ring, in which the continuous tension throughout the roof structure is made by continuous tension cables and discontinuous compression struts. These kinds of structures can be formed like spatially triangulated networks or like networks nontriangulated in space. This paper examines some effects of network geometry on the behaviour and structural efficiency of tensegrity type cable domes. In this paper the roof cover is considered non-interactive with the supporting structure, unlike rigidly clad tensegrity type cable domes. Since the main bearing elements of tensegrity type cable domes are prestressed cables, they show non-linear load deformation and rely upon geometric stiffness. A geometrically non-linear analysis of non-triangulated and triangulated structures for different load conditions was conducted employing a computer program based on the perturbation theory. The incrementally-iterative procedure, with an approximation of the stiffness matrix by combining the elastic and geometric stiffness matrix, allows detection of structural instabilities.

Tectonic origin and deformation process of the Mayer Kangri medium-high pressure metamorphic dome in Central Qiangtang of Tibet

Science.gov (United States)

Wang, Y.; Liang, X.

2016-12-01

The metamorphic characteristics, deformation process, geochronology of the medium-high pressure metamorphic rocks in blueschist bearing Central Qiangtang Metamorphic belt (CQMB) of Tibet were less well constrained. It is, however, commonly assumed that these rock slices in the margin also contain important implications on the evolution of the entire metamorphic belt. The well-exposed Mayer Kangri medium-high pressure metamorphic dome in north flank of the CQMB provides an unique opportunity to investigate the outer part of the CQMB, which could facilitate the study on the subduction-exhumation-post orogenic scenarios of the Triassic accretionary orogeny in Central Qiangtang. Field structural analyses indicate the Mayer Kangri metamorphic dome are bounded by low-angle normal faults (LANF) within the hanging wall of low-green schist facies mélange. It majorly consists of epidote-amphibolites, quartz-phengite schist, epidote-albite schist. The outcrop and micro structural observations of footwall metamorphic rocks show an open anticline with multiple foliation replacement, which largely differentiate themselves from the dextral strike-slip shearing of the hanging wall. Well-zoned amphiboles were found within the epidote-amphibolite after micro-structural observations and electron probe microanalyses (EPMA), which indicate that the amphibole zonation demonstrates a Hastingsite core, a Ferro-actinolite mantle and a Ferro-winchite rim in most cases. The mean temperature and pressure estimates of the zoned amphibolites change from 544 °, 0.98Gpa in the core, to 426°, 0.34Gpa in the mantle, and to ca.364° and 0.70 GPa in the rim. The detailed analyses on the stepwise-heating Ar-Ar results of the zoned amphiboles provide good constrains on the episodic deformation process of the CQMB. For Hast-cores, we obtained near plateau ages of 242.4-241.2 Ma, indicating the onset of the oceanic subduction is earlier than the Anisian stage of Middle Triassic. The subsequent

The two-dimensional cutting stock problem within the roller blind production process

NARCIS (Netherlands)

E.R. de Gelder; A.P.M. Wagelmans (Albert)

2007-01-01

textabstractIn this paper we consider a two-dimensional cutting stock problem encountered at a large manufacturer of window covering products. The problem occurs in the production process of made-to-measure roller blinds. We develop a solution method that takes into account the characteristics of

Distributions of cranial pathologies provide evidence for head-butting in dome-headed dinosaurs (Pachycephalosauridae.

Directory of Open Access Journals (Sweden)

Joseph E Peterson

Full Text Available Pachycephalosaurids are small, herbivorous dinosaurs with domed skulls formed by massive thickening of the cranial roof. The function of the dome has been a focus of debate: the dome has variously been interpreted as the product of sexual selection, as an adaptation for species recognition, or as a weapon employed in intraspecific combat, where it was used in butting matches as in extant ungulates. This last hypothesis is supported by the recent identification of cranial pathologies in pachycephalosaurids, which appear to represent infections resulting from trauma. However, the frequency and distribution of pathologies have not been studied in a systematic fashion. Here, we show that pachycephalosaurids are characterized by a remarkably high incidence of cranial injury, where 22% of specimens have lesions on the dome. Frequency of injury shows no significant difference between different genera, but flat-headed morphs (here interpreted as juveniles or females lack lesions. Mapping of injuries onto a digitial pachycephalosaurid skull shows that although lesions are distributed across the dome, they cluster near the apex, which is consistent with the hypothesis that the dome functioned for intraspecific butting matches.

Sensitivity of storage field performance to geologic and cavern design parameters in salt domes.

Energy Technology Data Exchange (ETDEWEB)

Ehgartner, Brian L. (Sandia National Laboratories, Albuquerque, NM); Park, Byoung Yoon

2009-03-01

A sensitivity study was performed utilizing a three dimensional finite element model to assess allowable cavern field sizes for strategic petroleum reserve salt domes. A potential exists for tensile fracturing and dilatancy damage to salt that can compromise the integrity of a cavern field in situations where high extraction ratios exist. The effects of salt creep rate, depth of salt dome top, dome size, caprock thickness, elastic moduli of caprock and surrounding rock, lateral stress ratio of surrounding rock, cavern size, depth of cavern, and number of caverns are examined numerically. As a result, a correlation table between the parameters and the impact on the performance of storage field was established. In general, slower salt creep rates, deeper depth of salt dome top, larger elastic moduli of caprock and surrounding rock, and a smaller radius of cavern are better for structural performance of the salt dome.

Bilateral Dome-Shaped Macula with Serous Macular Detachment in a Child

OpenAIRE

Cebeci, Zafer; Kir, Nur

2015-01-01

Dome-shaped macula is a structural disorder and optical coherence tomography (OCT) helps us to confirm macular convexity. We describe the first case of bilateral dome-shaped macula in an 8-year-old boy with subretinal fluid. The patient was diagnosed using spectral-domain OCT and received indocyanine green angiography-guided half-fluence photodynamic therapy as treatment.

Preliminary evaluation of steel-roller round baler for woody biomass baling

Science.gov (United States)

B. J. Stokes; D. L. Sirois; S. L. Woodfin

1987-01-01

A round hay baler with little modification was used to bale small-diameter, crushed trees. The trees had been crushed using a series of compression rollers. Bale cores had to be developed by hand before the baler became self-feeding. Windrowed material was packed off the ground by the baler system after a core had been developed.

Acceleration in One, Two, and Three Dimensions in Launched Roller Coasters

Science.gov (United States)

Pendrill, Ann-Marie

2008-01-01

During a roller coaster ride, the body experiences acceleration in three dimensions. An accelerometer can measure and provide a graph of the forces on the body during different parts of a ride. To couple the experience of the body to pictures of the ride and an analysis of data can contribute to a deeper understanding of Newton's laws. This…

[Dome-shaped macula: appearance on ultrasound and optical coherence tomography].

Science.gov (United States)

Chéour, M; Ben Aleya, N; Brour, J; Falfoul, Y; Agrebi, S; Skhiri, M; Kraïem, A

2013-10-01

The purpose of our work is to demonstrate the role of optical coherence tomography and ocular ultrasound in the diagnosis of the dome-shaped macula in high myopia. We report the case of a patient with high myopia who presented with a decrease in visual acuity and metamorphopsia in the left eye. She underwent visual acuity measurement, biomicroscopic examination and measurement of axial length. B-mode ultrasound and optical coherence tomography showed a projection of the macula in the convexity of the myopic staphyloma confirming the diagnosis of dome-shaped macula. Dome-shaped macula is a recently discovered entity, which may be responsible for a decrease in visual acuity in patients with high myopic posterior staphyloma. Ultrasound and optical coherence tomography are very helpful in making the diagnosis. Copyright © 2013. Published by Elsevier Masson SAS.

Corrective action decision document for the Roller Coaster Lagoons and North Disposal Trench (Corrective Action Unit Number 404)

International Nuclear Information System (INIS)

1997-01-01

The North Disposal Trench, located north of the eastern most lagoon, was installed in 1963 to receive solid waste and construction debris from the Operation Roller Coaster man camp. Subsequent to Operation Roller Coaster, the trench continued to receive construction debris and range cleanup debris (including ordnance) from Sandia National Laboratories and other operators. A small hydrocarbon spill occurred during Voluntary Corrective Action (VCA) activities (VCA Spill Area) at an area associated with the North Disposal Trench Corrective Action Site (CAS). Remediation activities at this site were conducted in 1995. A corrective action investigation was conducted in September of 1996 following the Corrective Action Investigation Plan (CAIP); the detailed results of that investigation are presented in Appendix A. The Roller Coaster Lagoons and North Disposal Trench are located at the Tonopah Test Range (TTR), a part of the Nellis Air Force Range, which is approximately 225 kilometers (140 miles) northwest of Las Vegas, Nevada, by air

The influence of increased distal loading on metabolic cost, efficiency, and kinematics of roller ski skating.

Science.gov (United States)

Bolger, Conor M; Bessone, Veronica; Federolf, Peter; Ettema, Gertjan; Sandbakk, Øyvind

2018-01-01

The purpose of the present study was to examine the influence of increased loading of the roller ski on metabolic cost, gross efficiency, and kinematics of roller ski skating in steep and moderate terrain, while employing two incline-specific techniques. Ten nationally ranked male cross-country skiers were subjected to four 7-minute submaximal intervals, with 0, 0.5, 1.0, and 1.5 kg added beneath the roller-ski in a randomized order. This was done on two separate days, with the G2 skating at 12% incline and 7 km/h speed and G3 skating at 5% incline and 14 km/h speed, respectively. At 12% incline, there was a significant increase in metabolic rate and a decrease in gross efficiency with added weight (P0.05). No changes in cycle characteristics were observed between the different ski loadings at either incline, although the lateral and vertical displacements of the foot/skis were slightly altered at 12% incline with added weight. In conclusion, the present study demonstrates that increased loading of the ski increases the metabolic cost and reduces gross efficiency during steep uphill roller skiing in G2 skating, whereas no significant effect was revealed when skating on relatively flat terrain in G3. Cycle characteristics remained unchanged across conditions at both inclines, whereas small adjustments in the displacement of the foot coincided with the efficiency changes in uphill terrain. The increased RPE values with added ski-weight at both inclines indicates that other factors than those measured here could have influenced effort and/or fatigue when lifting a heavier ski.

Metallogenetic modeling for uranium exploration in rocks of the Abaira-Jussiape Anticlinal nucleus, Chapada Diamantina, Bahia

International Nuclear Information System (INIS)

Santana, Jocilene dos Santos; Cruz, Simone Cerqueira Pereira; Barbosa, Johildo Salomao Figueiredo; Abram, Maisa Bastos; Martins, Adriano Alberto Marques

2011-01-01

The NNW-SSE-trending Abaira-Jussiape Anticlinal is an antiformal culmination of folding and shearing in the Paramirim Corridor of the Western Chapada Diamantina. In its core paleoproterozoic, mylonitized Caraguatai Suite, tonalites-granodiorites, alkali-feldspar granites, syenites to quartz-syenites and Jussiape Suite granites crop out. Compressional and distensional stresses mark the structural geology of the area. The compressional structures are related to two distinct deformation phases, named D1a and D1b. The main compressional phase is ductile D1a, which is related to the nucleation of dextral to dextral-reverse shearing zones. Deformation and syn-D1a recrystallization involving plagioclase and the K-feldspar suggest deformation temperature conditions above 550 deg C. The following phase D2 is of ductilebrittle nature and culminates in reverse shearing zones. The distensional structures correspond to the D3 phase and are represented by frontal shear zones with normal movement. The petrographic study helped identify a pre-D1a hydrothermal alteration process related to albitization and potassification, syn-D1 oxidation process, and hydration and saussuritization related to phases D2 and D3. The integration of lithological, petrographic, structural and geophysical data by means of the logic Fuzzy, plus the existing information regarding structural and lithologic controls of the known uranium mineralization in the Paramirim Corridor, led us to identify two promising areas for radioactive element exploration in the nucleus of Abaira-Jussiape Anticlinal. (author)

An optimum design on rollers containing the groove with changeable inner diameter based on response surface methodology

Directory of Open Access Journals (Sweden)

Xi Zhao

2016-05-01

Full Text Available In order to realize the precision plastic forming of the revolving body component with changeable wall thickness, a kind of roller containing grooves with changeable inner diameter is put forward, as the forming mould of the technology of rolling-extrusion. Specifically, first, the arc length of the groove in the roller is designed according to the prediction on the forward slip value during the process of forming, to make accurate control of the actual length of the forming segments; then, to obtain better parameters of the roller structure, a second-order response surface model combining finite element numerical simulation and response surface methodology was put forward, taking the factor of forming uniformity as evaluation index. The result of the experiment shows that, for the formed component, not only the size can meet the needs but also each mechanical property index can be greatly improved, which verify the rationality of the forward slip model and the structural parameter of the optimum model based on the response surface methodology.

The PLATO Dome A site-testing observatory: Power generation and control systems

Science.gov (United States)

Lawrence, J. S.; Ashley, M. C. B.; Hengst, S.; Luong-van, D. M.; Storey, J. W. V.; Yang, H.; Zhou, X.; Zhu, Z.

2009-06-01

The atmospheric conditions above Dome A, a currently unmanned location at the highest point on the Antarctic plateau, are uniquely suited to astronomy. For certain types of astronomy Dome A is likely to be the best location on the planet, and this has motivated the development of the Plateau Observatory (PLATO). PLATO was deployed to Dome A in early 2008. It houses a suite of purpose-built site-testing instruments designed to quantify the benefits of Dome A site for astronomy, and science instruments designed to take advantage of the observing conditions. The PLATO power generation and control system is designed to provide continuous power and heat, and a high-reliability command and communications platform for these instruments. PLATO has run and collected data throughout the winter 2008 season completely unattended. Here we present a detailed description of the power generation, power control, thermal management, instrument interface, and communications systems for PLATO, and an overview of the system performance for 2008.

consistencia en dome: un caso de estudio

Directory of Open Access Journals (Sweden)

DANIEL CABARCAS

2006-01-01

Full Text Available Las herramientas metaCASE ofrecen una funcionalidad similar a la de las herramientas CASE convencionales para notaciones gráficas arbitrarias, una vez estas notaciones le sean especificadas adecuadamente. La principal dificultad de dichas herramientas es la especificación de las diferentes reglas de consistencia, que deben tenerse en cuenta cuando se usa una notación. En este artículo se presenta la especificación de dos reglas de consistencia del diagrama de clases de UML en el metaCASE DOME, codificadas en el lenguaje de programación Alter. Adicionalmente, se hace un análisis comparativo entre las especificaciones de los aspectos estructurales y de las reglas de consistencia en DOME y en la especificación de UML provista por el OMG.

Longitudinal Biases in the Seychelles Dome Simulated by 34 Ocean-Atmosphere Coupled General Circulation Models

Science.gov (United States)

Nagura, M.; Sasaki, W.; Tozuka, T.; Luo, J.; Behera, S. K.; Yamagata, T.

2012-12-01

The upwelling dome of the southern tropical Indian Ocean is examined by using simulated results from 34 ocean-atmosphere coupled general circulation models (CGCMs) including those from the phase five of the Coupled Model Intercomparison Project (CMIP5). Among the current set of the 34 CGCMs, 12 models erroneously produce the upwelling dome in the eastern half of the basin while the observed Seychelles Dome is located in the southwestern tropical Indian Ocean (Figure 1). The annual mean Ekman pumping velocity is almost zero in the southern off-equatorial region in these models. This is in contrast with the observations that show Ekman upwelling as the cause of the Seychelles Dome. In the models that produce the dome in the eastern basin, the easterly biases are prominent along the equator in boreal summer and fall that cause shallow thermocline biases along the Java and Sumatra coasts via Kelvin wave dynamics and result in a spurious upwelling dome there. In addition, these models tend to overestimate (underestimate) the magnitude of annual (semiannual) cycle of thermocline depth variability in the dome region, which is another consequence of the easterly wind biases in boreal summer-fall. Compared to the CMIP3 models (Yokoi et al. 2009), the CMIP5 models are even worse in simulating the dome longitudes and magnitudes of annual and semiannual cycles of thermocline depth variability in the dome region. Considering the increasing need to understand regional impacts of climate modes, these results may give serious caveats to interpretation of model results and help in further model developments.; Figure 1: The longitudes of the shallowest annual-mean D20 in 5°S-12°S. The open and filled circles are for the observations and the CGCMs, respectively.

Effective pine bark composting with the Dome Aeration Technology

International Nuclear Information System (INIS)

Trois, Cristina; Polster, Andreas

2007-01-01

In South Africa garden refuse is primarily disposed of in domestic landfills. Due to the large quantities generated, any form of treatment would be beneficial for volume reduction, waste stabilization and resource recovery. Dome Aeration Technology (DAT) is an advanced process for aerobic biological degradation of garden refuse and general waste [Paar, S., Brummack, J., Gemende, B., 1999a. Advantages of dome aeration in mechanical-biological waste treatment. In: Proceedings of the 7th International Waste Management and Landfill Symposium, Cagliari, 4-8 October 1999; Paar, S., Brummack, J., Gemende, B., 1999b. Mechanical-biological waste stabilization by the dome aeration method. Environment Protection Engineering 25 (3/99). Mollekopf, N., Brummack, J., Paar, S., Vorster, K., 2002. Use of the Dome Aeration Technology for biochemical stabilization of waste prior to landfilling. In: Proceedings of the Wastecon 2002, Waste Congress and Exhibition, Durban, South Africa.]. It is a non-reactor open windrow composting process, with the main advantage being that the input material needs no periodic turning. A rotting time of only 3-4 months indicates the high efficiency. Additionally, the low capital/operational costs, low energy inputs and limited plant requirements provide potential for use in aerobic refuse stabilization. The innovation in the DAT process is the passive aeration achieved by thermally driven advection through open windrows caused by temperature differences between the degrading material and the outside environment. This paper investigates the application of Dome Aeration Technology to pine bark composting as part of an integrated waste management strategy. A full-scale field experiment was performed at the Bisasar Road Landfill Site in Durban to assess the influence of climate, waste composition and operational conditions on the process. A test windrow was constructed and measurements of temperature and airflow through the material were taken. The process

Repair of manufacturing defects in the armor of plasma facing units of the ITER Divertor Dome

International Nuclear Information System (INIS)

Litunovsky, Nikolay; Alekseenko, Evgeny; Kuznetsov, Vladimir; Lyanzberg, Dmitriy; Makhankov, Aleksey; Rulev, Roman

2013-01-01

Highlights: • Sporadic manufacturing defects in ITER Divertor Dome PFUs may be repaired. • We have developed a repair technique for ITER Divertor Dome PFUs. • Armor repair technique for ITER Divertor Dome PFUs is successfully tested. -- Abstract: The paper describes the repair procedure developed for removal of manufacturing defects occurring sporadically during armoring of plasma facing units (PFUs) of the ITER Divertor Dome. Availability of armor repair technique is prescribed by the procurement arrangement for the ITER Divertor Dome concluded in 2009 between the ITER Organization and the ITER Domestic Agency of Russia. The paper presents the detailed description of the procedure, data on its effect on the joints of the rest part of the armor and on the grain structure of the PFU heat sink. The results of thermocycling of large-scale Dome PFU mock-ups manufactured with demonstration of armor repair are also given

Repair of manufacturing defects in the armor of plasma facing units of the ITER Divertor Dome

Energy Technology Data Exchange (ETDEWEB)

Litunovsky, Nikolay, E-mail: nlitunovsky@sintez.niiefa.spb.su; Alekseenko, Evgeny; Kuznetsov, Vladimir; Lyanzberg, Dmitriy; Makhankov, Aleksey; Rulev, Roman

2013-10-15

Highlights: • Sporadic manufacturing defects in ITER Divertor Dome PFUs may be repaired. • We have developed a repair technique for ITER Divertor Dome PFUs. • Armor repair technique for ITER Divertor Dome PFUs is successfully tested. -- Abstract: The paper describes the repair procedure developed for removal of manufacturing defects occurring sporadically during armoring of plasma facing units (PFUs) of the ITER Divertor Dome. Availability of armor repair technique is prescribed by the procurement arrangement for the ITER Divertor Dome concluded in 2009 between the ITER Organization and the ITER Domestic Agency of Russia. The paper presents the detailed description of the procedure, data on its effect on the joints of the rest part of the armor and on the grain structure of the PFU heat sink. The results of thermocycling of large-scale Dome PFU mock-ups manufactured with demonstration of armor repair are also given.

Experimental studies in Ultrasonic Pulse Velocity of roller compacted concrete pavement containing fly ash and M-sand

Directory of Open Access Journals (Sweden)

S. Krishna Rao

2016-07-01

Full Text Available This paper presents the experimental investigation results of Ultrasonic Pulse Velocity (UPV tests conducted on roller compacted concrete pavement (RCCP material containing Class F fly ash of as mineral admixture. River sand, M-sand and combination of M-sand and River sand are used as fine aggregate in this experimental work. Three types of fly ash roller compacted concrete mixes are prepared using above three types of fine aggregates and they are designated as Series A (River sand, Series B (manufactured sand and Series C (combination of River sand and M-sand. In each series the fly ash content in place of cement is varied from 0% to 60%. In each series and for different ages of curing (i.e 3, 7, 28 and 90 days forty two cube specimens are cast and tested for compressive strength and UPV. The UPV results of fly ash containing roller compacted concrete pavement (FRCCP show lower values at all ages from 3 days to 90 days in comparison with control mix concrete (0% fly ash in all mixes. However, it is also observed that Series B and C mixes containing fly ash show better results in UPV values, compressive strength and Dynamic Elastic Modulus in comparison to Series A mixes with fly ash. Relationships between compressive strength of FRCCP and UPV and Dynamic Elastic Modulus are proposed for all series mixes. A new empirical equation is proposed to determine the Dynamic Elastic Modulus of FRCCP. Keywords: Compressive strength, Dynamic Elastic Modulus, Fly ash, Roller compacted concrete pavement, Ultrasonic Pulse Velocity

DOME-SHAPED MACULA IN MYOPIC EYES: Twelve-Month Follow-up.

Science.gov (United States)

Lorenzo, Daniel; Arias, Luis; Choudhry, Netan; Millan, Eduard; Flores, Ignacio; Rubio, Marcos J; Cobos, Estefanía; García-Bru, Pere; Filloy, Alejandro; Caminal, Josep M

2017-04-01

To study the long-term clinical course of dome-shaped macula in myopic eyes and to evaluate treatment efficacy for subretinal fluid (SRF) as a related complication. A retrospective, single-center consecutive case series study was conducted. The authors analyzed myopic eyes with dome-shaped macula in patients who presented for evaluation of decreased vision. Dome-shaped macula was defined as a convexity of the retina-choroidal macular complex seen on spectral domain optical coherence tomography images. All patients were followed for at least 12 months (mean, 25 months). Fluorescein angiography and/or indocyanine green angiography were performed in cases with SRF to rule out choroidal neovascularization. A total of 56 dome-shaped macula eyes from 36 patients were included in the study (bilateral in 55% of patients). Mean patient age was 56.9 ± 13.1 years. The mean spherical equivalent was -9.1 ± 6.0 diopters; 53% of eyes were considered highly myopic (>-6 diopters) and 47% of eyes were mildly myopic. In most cases (37 eyes; 66.1%), the dome-shaped macula was detected on vertical spectral domain optical coherence tomography scan patterns. No significant changes (P ≥ 0.1) were observed in mean best-corrected visual acuity or mean central foveal thickness from baseline to final follow-up. Subretinal fluid was present in 29 eyes (51.8%) at baseline, with no differences in best-corrected visual acuity in eyes with and without SRF (P ≥ 0.05). Nineteen of the 29 SRF eyes were treated: 8 underwent low-fluence photodynamic therapy, whereas 7 received bevacizumab, and 4 ranibizumab. No significant differences were found between treated and untreated SRF eyes in best-corrected visual acuity improvement (P ≥ 0.1), or complete resolution of SRF (P ≥ 0.1). Likewise, photodynamic therapy did not yield any significant benefit versus untreated eyes in best-corrected visual acuity or improvement of SRF. Dome-shaped macula is a condition associated with myopic eyes that seems

Location of a new ice core site at Talos Dome (East Antarctica

Directory of Open Access Journals (Sweden)

I. Tabacco

2006-06-01

Full Text Available In the frame of glaciology and palaeoclimate research, Talos Dome (72°48lS; 159°06lE, an ice dome on the East Antarctic plateau, represents the new selected site for a new deep ice core drilling. The increasing interest in this region is due to the fact that the ice accumulation is higher here than in other domes in East Antarctica. A new deep drilling in this site could give important information about the climate changes near the coast. Previous papers showed that the dome summit is situated above a sloped bedrock. A new position on a relatively flat bedrock 5-6 km far from here in the SE direction was defined as a possible new ice core site for an European (Italy, France, Swiss and United Kingdom drilling project named as TALDICE (TALos Dome Ice Core Project. This point, named as ID1 (159°11l00mE; 72°49l40mS, became the centre of the Radio Echo Sounding (RES flight plan during the 2003 Italian Antarctic expedition, with the aim of confirming the new drilling site choice. In this paper 2001 and 2003 RES data sets have been used to draw a better resolution of ice thickness, bottom morphology and internal layering of a restricted area around the dome. Based on the final results, point ID1 has been confirmed as the new coring site. Finally, the preliminary operations about the installation of the summer ice core camp (TALDICE at ID1 site carried out during the XX Italian Antarctic expedition (November 2004-December 2005 are briefly described.

Interpreting Fracture Patterns in Sandstones Interbedded with Ductile Strata at the Salt Valley Anticline, Arches National Park, Utah

OpenAIRE

Lorenz, John C.; Cooper, Scott P.

2001-01-01

Sandstones that overlie or that are interbedded with evaporitic or other ductile strata commonly contain numerous localized domains of fractures, each covering an area of a few square miles. Fractures within the Entrada Sandstone at the Salt Valley Anticline are associated with salt mobility within the underlying Paradox Formation. The fracture relationships observed at Salt Valley (along with examples from Paleozoic strata at the southern edge of the Holbrook basin in northeastern Arizona, a...

Is there 1.5-million-year-old ice near Dome C, Antarctica?

Directory of Open Access Journals (Sweden)

F. Parrenin

2017-11-01

Full Text Available Ice sheets provide exceptional archives of past changes in polar climate, regional environment and global atmospheric composition. The oldest dated deep ice core drilled in Antarctica has been retrieved at EPICA Dome C (EDC, reaching ∼ 800 000 years. Obtaining an older paleoclimatic record from Antarctica is one of the greatest challenges of the ice core community. Here, we use internal isochrones, identified from airborne radar coupled to ice-flow modelling to estimate the age of basal ice along transects in the Dome C area. Three glaciological properties are inferred from isochrones: surface accumulation rate, geothermal flux and the exponent of the Lliboutry velocity profile. We find that old ice (> 1.5 Myr, 1.5 million years likely exists in two regions: one ∼ 40 km south-west of Dome C along the ice divide to Vostok, close to a secondary dome that we name Little Dome C (LDC, and a second region named North Patch (NP located 10–30 km north-east of Dome C, in a region where the geothermal flux is apparently relatively low. Our work demonstrates the value of combining radar observations with ice flow modelling to accurately represent the true nature of ice flow, and understand the formation of ice-sheet architecture, in the centre of large ice sheets.

Choroidal findings in dome-shaped macula in highly myopic eyes: a longitudinal study.

Science.gov (United States)

Viola, Francesco; Dell'Arti, Laura; Benatti, Eleonora; Invernizzi, Alessandro; Mapelli, Chiara; Ferrari, Fabio; Ratiglia, Roberto; Staurenghi, Giovanni; Barteselli, Giulio

2015-01-01

To describe choroidal findings in dome-shaped macula associated with high myopia using fluorescein angiography (FA), indocyanine green angiography (ICGA), and spectral-domain optical coherence tomography (SD OCT), and to elucidate the mechanism and natural course of serous retinal detachment (RD) associated with dome-shaped macula. Retrospective, observational case series. We reviewed longitudinal imaging results of 52 highly myopic eyes with dome-shaped macula. Changes on FA and ICGA were assessed. Retinal, choroidal, and scleral thicknesses and bulge height were measured on SD OCT. Serous RD was the most common abnormality associated with dome-shaped macula, detected by SD OCT in 44% of the cases with no associated choroidal neovascularization. Significant differences in the proportion of eyes with pinpoint leakage on FA (P macula was likely caused by choroidal vascular changes, similar to central serous chorioretinopathy, but specifically confined in the inward bulge of the staphyloma and secondary to excessive scleral thickening. Serous retinal detachment showed fluctuating changes over time, with alternating active and inactive stages. Angiographic findings in dome-shaped macula suggest the choroid as a target for possible treatment strategies. Copyright © 2015 Elsevier Inc. All rights reserved.

3-DIMENSIONAL Geometric Survey and Structural Modelling of the Dome of Pisa Cathedral

Science.gov (United States)

Aita, D.; Barsotti, R.; Bennati, S.; Caroti, G.; Piemonte, A.

2017-02-01

This paper aims to illustrate the preliminary results of a research project on the dome of Pisa Cathedral (Italy). The final objective of the present research is to achieve a deep understanding of the structural behaviour of the dome, through a detailed knowledge of its geometry and constituent materials, and by taking into account historical and architectural aspects as well. A reliable survey of the dome is the essential starting point for any further investigation and adequate structural modelling. Examination of the status quo on the surveys of the Cathedral dome shows that a detailed survey suitable for structural analysis is in fact lacking. For this reason, high-density and high-precision surveys have been planned, by considering that a different survey output is needed, according both to the type of structural model chosen and purposes to be achieved. Thus, both range-based (laser scanning) and image-based (3D Photogrammetry) survey methodologies have been used. This contribution introduces the first results concerning the shape of the dome derived from surveys. Furthermore, a comparison is made between such survey outputs and those available in the literature.

Evaluation of radar imagery of the North Louisiana Salt Dome Area

International Nuclear Information System (INIS)

Dellwig, L.F.

1977-01-01

Radar (SLAR) is basically a reconnaissance tool. It has proved to be most effective in the identification of regional structures, trends or fracture patterns which might be expressed in such a way as to affect (1) the roughness of the target (soil, rock or vegetation), (2) its dielectric properties (chemical composition, moisture content), or (3) its topographic expression. Topographic expression of domes is only poorly to moderately identifiable. Significant associated fractures cannot be detected. Vegetative anomalies are associated with many known domes, and are suggestive of the existence of numerous others. The validity of such anomalies as indicators of domes has yet to be, but should be, determined by field investigations. In the light of the poor to near lack of topographic expression of the domes or associated faults it is obvious that identification of recent movement is not to be expected. Such conclusions apply only to this environment and do not in any way mean to degrade the quality of the imagery. They do, however, point out the importance of understanding energy-target interaction and target and terrain characteristics in the mission planning phase of any further investigations

An application of LOTEM around salt dome near Houston, Texas

Science.gov (United States)

Paembonan, Andri Yadi; Arjwech, Rungroj; Davydycheva, Sofia; Smirnov, Maxim; Strack, Kurt M.

2017-07-01

A salt dome is an important large geologic structure for hydrocarbon exploration. It may seal a porous reservoir of rocks that form petroleum reservoirs. Several techniques such as seismic, gravity, and electromagnetic including magnetotelluric have successfully yielded salt dome interpretation. Seismic has difficulties seeing through the salt because the seismic energy gets trapped by the salt due to its high velocity. Gravity and electromagnetics are more ideal methods. Long Offset Transient Electromagnetic (LOTEM) and Focused Source Electromagnetic (FSEM) were tested over a salt dome near Houston, Texas. LOTEM data were recorded at several stations with varying offset, and the FSEM tests were also made at some receiver locations near a suspected salt overhang. The data were processed using KMS's processing software: First, for assurance, including calibration and header checking; then transmitter and receiver data are merged and microseismic data is separated; Finally, data analysis and processing follows. LOTEM processing leads to inversion or in the FSEM case 3D modeling. Various 3D models verify the sensitivity under the salt dome. In addition, the processing was conducted pre-stack, stack, and post-stack. After pre-stacking, the noise was reduced, but showed the ringing effect due to a low-pass filter. Stacking and post-stacking with applying recursive average could reduce the Gibbs effect and produce smooth data.

Degeneracy lifting due to thermal fluctuations around the frustration point between anticlinic antiferroelectric SmC(A)* and synclinic ferroelectric SmC*.

Science.gov (United States)

Sandhya, K L; Chandani, A D L; Fukuda, Atsuo; Vij, Jagdish K; Emelyanenko, A V; Ishikawa, Ken

2013-01-01

In the binary mixture phase diagram of MC881 and MC452, the borderline between anticlinic antiferroelectric SmC(A)(*) and synclinic ferroelectric SmC(*) becomes apparently parallel to the temperature ordinate axis at the critical concentration r(c). The free energy difference between SmC(A)(*) and SmC^{*} is extremely small in a wide temperature range near r(c). In such circumstances, by observing Bragg reflection spectra due to the director helical structure and electric-field-induced birefringence, we have observed the continuous change from SmC(A)(*) to SmC(*) for r/~r(c). These intriguing phenomena have been explained, successfully at least in the high-temperature region, by a thermal equilibrium between the synclinic and anticlinic orderings and the resulting Boltzmann distribution for the ratio between them; the thermal equilibrium is considered to be attained in a nonuniform defect-assisted way through solitary waves moving around dynamically. We have also discussed qualitatively an important role played by the effective long-range interlayer interactions in the low-temperature region.

FLAMMABLE GAS DIFFUSION THROUGH SINGLE SHELL TANK (SST) DOMES

Energy Technology Data Exchange (ETDEWEB)

MEACHAM, J.E.

2003-11-10

This report quantified potential hydrogen diffusion through Hanford Site Single-Shell tank (SST) domes if the SSTs were hypothetically sealed airtight. Results showed that diffusion would keep headspace flammable gas concentrations below the lower flammability limit in the 241-AX and 241-SX SST. The purpose of this document is to quantify the amount of hydrogen that could diffuse through the domes of the SSTs if they were hypothetically sealed airtight. Diffusion is assumed to be the only mechanism available to reduce flammable gas concentrations. The scope of this report is limited to the 149 SSTs.

The geology and mechanics of formation of the Fort Rock Dome, Yavapai County, Arizona

Science.gov (United States)

Fuis, Gary S.

1996-01-01

The Fort Rock Dome, a craterlike structure in northern Arizona, is the erosional product of a circular domal uplift associated with a Precambrian shear zone exposed within the crater and with Tertiary volcanism. A section of Precambrian to Quaternary rocks is described, and two Tertiary units, the Crater Pasture Formation and the Fort Rock Creek Rhyodacite, are named. A mathematical model of the doming process is developed that is consistent with the history of the Fort Rock Dome.

Precocious development of lectin (Ulex europaeus agglutinin I) receptors in dome epithelium of gut-associated lymphoid tissues.

Science.gov (United States)

Roy, M J

1987-06-01

Dome epithelium (DE), the tissue covering lymphoid domes of gut-associated lymphoid tissues, was examined in both adult and neonatal rabbit appendix or sacculus rotundus to determine if dome epithelial cells matured earlier than epithelial cells covering adjacent villi. The localization of well-differentiated epithelial cells in rabbit gut-associated lymphoid tissues (GALT) was accomplished histochemically by use of molecular probes: fluorescein isothiocyanate or horseradish peroxidase conjugates of Ulex europaeus agglutinin I (UEA), a lectin specific for terminal L-fucose molecules on certain glycoconjugates. The villus epithelial cells of newborn and 2-, 5-, or 10-day-old rabbits did not bind UEA, but between the twelfth and fifteenth days of postnatal life, UEA receptors were expressed by well-differentiated villus epithelial cells. In contrast to villus epithelium, DE in appendix and sacculus rotundus of neonatal rabbits expressed UEA receptors two days after birth, a feature that distinguished the DE of neonatal GALT for the next two weeks. In adult rabbits, UEA receptors were associated with dome epithelial cells extending from the mouths of glandular crypts to the upper domes; in contrast to the domes, UEA receptors were only present on well-differentiated epithelial cells at the villus tips. Results suggested that in neonatal rabbits most dome epithelial cells developed UEA receptors shortly after birth, reflecting precocious development of DE as compared to villus epithelium. In adult rabbit dome epithelium UEA receptors appeared on dome epithelial cells as they left the glandular crypts, representing accelerated epithelial maturation.

Study on the Effect of Steel Wheel and Ground on Single Steel Vibratory Roller

Science.gov (United States)

Li, Jiabo; You, Guanghui; Qiao, Jiabin; Ye, Min; Guo, Jin; Zhang, Hongyang

2018-03-01

In the compacting operation of single drum vibratory roller, the forces acting on the foundation of drum include the weight of the drum, the weight of the frame, the exciting force and so on. Based on the theoretical study of ground mechanics, this paper analyzes and calculates the forces acting on the steel wheel and the ground, and obtains the distribution of the laminar stress in the ground when the working plane vibrates. Derive the formula of dynamic compressive stress and static compressive stress in the foundation during vibration compaction. Through the compaction test of the soil trough of 20T single drum roller, the compressive stress data of the soil hydraulic field are obtained. The data of the dynamic compressive stress and the static compressive stress of each layer during the third compaction are obtained, and the theoretical research is verified.

The Senior Capstone, Dome or Spire?

Science.gov (United States)

Heinemann, Robert L.

This paper examines a basic philosophical issue involved with the purpose of a senior capstone communication course required of all majors. The issue involves two opposites: closure, represented by the dome, and further exploration, represented by the spire. Both approaches have legitimate claims for a capstone course. There is definitely a need…

Features of Bayou Choctaw SPR caverns and internal structure of the salt dome.

Energy Technology Data Exchange (ETDEWEB)

Munson, Darrell E.

2007-07-01

The intent of this study is to examine the internal structure of the Bayou Choctaw salt dome utilizing the information obtained from graphical representations of sonar survey data of the internal cavern surfaces. Many of the Bayou Choctaw caverns have been abandoned. Some existing caverns were purchased by the Strategic Petroleum Reserve (SPR) program and have rather convoluted histories and complex cavern geometries. In fact, these caverns are typically poorly documented and are not particularly constructive to this study. Only two Bayou Choctaw caverns, 101 and 102, which were constructed using well-controlled solutioning methods, are well documented. One of these was constructed by the SPR for their use while the other was constructed and traded for another existing cavern. Consequently, compared to the SPR caverns of the West Hackberry and Big Hill domes, it is more difficult to obtain a general impression of the stratigraphy of the dome. Indeed, caverns of Bayou Choctaw show features significantly different than those encountered in the other two SPR facilities. In the number of abandoned caverns, and some of those existing caverns purchased by the SPR, extremely irregular solutioning has occurred. The two SPR constructed caverns suggest that some sections of the caverns may have undergone very regular solutioning to form uniform cylindrical shapes. Although it is not usually productive to speculate, some suggestions that point to the behavior of the Bayou Choctaw dome are examined. Also the primary differences in the Bayou Choctaw dome and the other SPR domes are noted.

Design Of a Fixed-Dome Ferrocement Biodigester Built Partiall y Underground

OpenAIRE

Marianela de la Caridad Ortiz Alvarez; Hugo Rafael Wainshtok Rivas; Henry Hernández Sotomayor

2016-01-01

The analysis, structural design and constructive sequence of a fixed-dome biodigester built partially underground and using ferrocement as construction material under normal work conditions is in this paper developed. The biodigester capacity is 24 m3 and it is composed by a semispherical dome (cover), cylindricalwalls (body) and a circular slab(bottom). The biodigester using ferrocement as construction materialis in agreement with the service guaranty requirements settled for the established...

Investigating possible use of roller bearings made of plastic in belt conveyor idlers

Energy Technology Data Exchange (ETDEWEB)

Grzeszek, A

1979-05-01

This paper presents results of laboratory and operational tests of roller bearings made of polyamide in belt conveyor idlers. During operational tests the conveyor was inclined to one side so the load on individual bearings varied and the bearings were also covered with dust and dirt. The tests show that the first failures of the plastic bearings took place after 3 months but some of the bearings were in operation one year without failures. All the failures were caused by wear of the bearing due to dust and dirt on their sliding surface. Increased friction resulted in higher temperatures which deformed the bearings. The tests showed that the bearings which were not dirty operated without failure. It is concluded that the plastic-made roller bearings cannot be used under conditions of brown coal surface mines as these mines are characterized by intense dustfall and by dirt which would increase friction in the bearings. (In Polish)

Rereading "The Jack-Roller:" Hidden Histories in Sociology and Social Work

Science.gov (United States)

Shaw, Ian

2009-01-01

I revisit one of the iconic Chicago School studies, Clifford Shaw's "The Jack-Roller". A naive reading of Shaw's book leaves the reader with a sense of having been inducted into a melange of what we now know as "sociology" and "social work," but which to Shaw seems a coherent stance. I suggest that this is close to the heart of how things were,…

Airborne photogrammetry and geomorphological analysis of the 2001-2012 exogenous dome growth at Molodoy Shiveluch Volcano, Kamchatka

Science.gov (United States)

Shevchenko, A. V.; Dvigalo, V. N.; Svirid, I. Yu.

2015-10-01

In 2001, after a six-year pause in extrusive activity, lava dome growth resumed at Molodoy Shiveluch Volcano. The new period of dome growth (2001-present) has morphological features that were uncommon during the previous periods of the dome formation (1980-1981, 1993-1995): numerous lava lobes and crease structures. Thus, the current dome growth is mostly of an exogenous type with short periods of endogenous growth that occurred in 2003, 2005, and 2010. Geomorphological interpretation of stereo photo images has revealed elements of the dome that are hardly distinguishable in single photographs. We have made detailed descriptions of the dome morphology covering all the dates of the available images. By using photogrammetric processing of aerial photographs, we created Digital Terrain Models and topographic maps of the lava dome and defined its volumes for 2001 (0.19 km3), 2003 (0.47 km3), 2005 (0.48 km3), 2010 (0.54 km3), and 2012 (0.63 km3). We also defined other morphometric characteristics: absolute and relative heights, as well as the dimensions of the dome and its elements for the investigated period. Taking into account large partial failures of the dome in 2005 (>0.11 km3) and 2010 (0.28 km3), we suggest that the volume of the extruded material for the whole 1980-2012 period was no less than 1.02 km3. The average extrusion rate over the 2001-2012 period exceeded 225,000 m3/day. The transition from endogenous to exogenous dome growth was possibly caused by change in extruded material physical properties due to an increase of SiO2. On the basis of geomorphological analysis of the current lava dome features, we suggest the possible process of the exogenous dome formation at Molodoy Shiveluch. The crease structures detected at Molodoy Shiveluch were classified into three groups according to their shapes: radial, bilaterally symmetrical, and irregular. These crease structures are morphologically similar to those formed at Unzen Volcano during the 1990

Hyperthyroidism with dome-and-dart T wave: A case report: A care-compliant article.

Science.gov (United States)

Lai, Ping; Yuan, Jing-Ling; Xue, Jin-Hua; Qiu, Yue-Qun

2017-02-01

Dome-and-dart T waves (or bifid T waves) are a rare phenomenon in the surface electrocardiogram. These wave forms are mainly observed in patients with congenital heart disease such as atrial septal defect and ventricular septal defect. And hyperthyroidism who presented with an electrocardiogram that had dome-and-dart T waves in a precordial lead is never been reported. The patient presented with continuous tachycardia, palpitations, chest tightness, and headache for 4 days, and aggravated for 1 day. Hyperthyroidism. Methimazole. All symptoms were alleviated. Dome-and-dart or bifid T waves have been reported in the conventional 12-lead electrocardiograms in some patients with congenital heart disease. The case illustrated here, to the best of our knowledge, dome-and-dart or bifid T waves may associate with hyperthyroidism patients.

Robotic Manufacturing of 5.5 Meter Cryogenic Fuel Tank Dome Assemblies for the NASA Ares I Rocket

Science.gov (United States)

Jones, Ronald E.

2012-01-01

The Ares I rocket is the first launch vehicle scheduled for manufacture under the National Aeronautic and Space Administration's (NASA's) Constellation program. A series of full-scale Ares I development articles have been constructed on the Robotic Weld Tool at the NASA George C. Marshall Space Flight Center in Huntsville, Alabama. The Robotic Weld Tool is a 100 ton, 7-axis, robotic manufacturing system capable of machining and friction stir welding large-scale space hardware. This presentation will focus on the friction stir welding of 5.5m diameter cryogenic fuel tank components; specifically, the liquid hydrogen forward dome (LH2 MDA), the common bulkhead manufacturing development articles (CBMDA) and the thermal protection system demonstration dome (TPS Dome). The LH2 MDA was the first full-scale, flight-like Ares I hardware produced under the Constellation Program. It is a 5.5m diameter elliptical dome assembly consisting of eight gore panels, a y-ring stiffener and a manhole fitting. All components are made from aluminumlithium alloy 2195. Conventional and self-reacting friction stir welding was used on this article. An overview of the manufacturing processes will be discussed. The LH2 MDA is the first known fully friction stir welded dome ever produced. The completion of four Common Bulkhead Manufacturing Development Articles (CBMDA) and the TPS Dome will also be highlighted. Each CBMDA and the TPS Dome consists of a 5.5m diameter spun-formed dome friction stir welded to a y-ring stiffener. The domes and y-rings are made of aluminum 2014 and 2219 respectively. The TPS Dome has an additional aluminum alloy 2195 barrel section welded to the y-ring. Manufacturing solutions will be discussed including "fixtureless" welding with self reacting friction stir welding.

Geologic nuclear waste repository site selection studies in the Paradox Basin, Utah

International Nuclear Information System (INIS)

Rogers, T.H.; Conwell, F.R.

1981-01-01

During Phase I regional-level studies, a literature review was conducted to ascertain geologic characteristics pertinent to repository siting factors. On the basis of the regional screening results, four areas in southeastern Utah were selected as being suitable for more detailed study in Phase II: Elk Ridge and Gibson Dome, containing nearly horizontal bedded salt deposits; Salt Valley, containing a diapiric salt anticline; and Lisbon Valley, containing a non-diapiric salt anticline. During current Phase II area studies, the four study areas are being characterized in greater detail than in Phase I. Phase II will culminate in the identification of a potentially suitable location(s), if any, that will be recommended for study in still greater detail in a subsequent phase of work. 5 refs

Out-of-plane stability of roller bent steel arches – an experimental investigation

NARCIS (Netherlands)

La Poutre, D.B.; Spoorenberg, R.C.; Snijder, H.H.; Hoenderkamp, J.C.D.

2013-01-01

This paper presents an experimental investigation of the elastic-plastic out-of-plane buckling response of roller bent circular steel arches subjected to a single force applied to the crown. The experiments are used to validate a finite element model described in a related paper. A series of 15

Crystal-rich lava dome extrusion during vesiculation: An experimental study

Science.gov (United States)

Pistone, Mattia; Whittington, Alan G.; Andrews, Benjamin J.; Cottrell, Elizabeth

2017-11-01

Lava dome-forming eruptions represent a common eruptive style and a major hazard at numerous active volcanoes worldwide. The extrusion mechanics of crystal-rich lava domes and the influence of volatiles on the transition from viscous to brittle behaviour during lava dome extrusion remain unclear. Understanding how gas exsolution and crystallinity control effusive versus explosive eruption behaviour is essential. Here, we present new experimental results on the rheology of synthesised, crystal-rich (50 to 80 vol% quartz crystals), hydrous (4.2 wt% H2O in the glass) dacite samples, which vesiculate from 5 to 27 vol% gas bubbles at high temperatures (from glass transition temperature to 797 °C) during deformation conducted in a parallel plate viscometer (constant stress at 0.63-0.64 MPa, and variable strain-rates ranging from 8.32·10- 8 to 3.58·10- 5 s- 1). The experiments reproduce certain aspects of lava dome deformation in volcanic conduits during vesiculation of the residual melt, instigated in the experiments by increasing temperature. During gas exsolution (i.e. nucleation and growth of gas-pressurised bubbles) and volume inflation, we find that the rheological lubrication of the system during deformation is strongly dictated by the initial crystallinity. At crystal contents < 60 vol%, gas bubbles form and coalesce during expansion and viscous deformation, favouring strain localisation and gas permeability within shear bands, which control the overall sample rheology. At crystallinities of 60 to 70 vol%, gas exsolution generates pressurisation (i.e. pore pressure increase) within the bubbles trapped in the solid crystal clusters, and embryonic formation of microscopic fractures through melt and crystals drives the system to a brittle behaviour. At higher crystallinity (80 vol%) vesiculation leads to large pressurisation, which then triggers extensive brittle fragmentation. Through macroscopic fractures, outgassing determines the rheological stalling of the

Early Miocene rapid exhumation in southern Tibet: Insights from P-T-t-D-magmatism path of Yardoi dome

Science.gov (United States)

Wang, Jia-Min; Wu, Fu-Yuan; Rubatto, Daniela; Liu, Kai; Zhang, Jin-Jiang; Liu, Xiao-Chi

2018-04-01

Reconstructing the evolution of Gneiss domes within orogenic belts poses challenges because domes can form in a variety of geodynamic settings and by multiple doming mechanisms. For the North Himalayan gneiss domes (NHGD), it is debated whether they formed during shortening, extension or collapse of the plateau, and what is the spatial and temporal relationship of magmatism, metamorphism and deformation. This study investigates the Yardoi dome in southern Tibet using field mapping, petrography, phase equilibria modelling and new monazite ages. The resulting P-T-time-deformation-magmatism path for the first time reveals the spatial and temporal relationship of metamorphism, deformation and magmatism in the Yardoi dome: a) the dome mantle recorded prograde loading to kyanite-grade Barrovian metamorphic conditions of 650 ± 30 °C and 9 ± 1 kbar (M2) in the Early Miocene (18-17 Ma); b) the main top-to-the-north deformation fabric (D2) formed syn- to post-peak-metamorphism; c) the emplacement of leucorgranites related to doming is syn-metamorphism at 19-17 Ma. The link between the detachment shear zone in the Yardoi dome and the South Tibetan detachment system (STDS) is confirmed. By comparing with orogen-scale tectonic processes in the Himalaya, we suggest that north-south extension in a convergent geodynamic setting during Early Miocene accounts for formation of the Yardoi dome. In a wider tectonic context, the Early Miocene rapid exhumation of deep crustal rocks was contemporaneous with the rapid uplift of southern Tibet and the Himalayan orogen.

A comparison of surgical exposures for posterolateral osteochondral lesions of the talar dome.

Science.gov (United States)

Mayne, Alistair I W; Lawton, Robert; Reidy, Michael J; Harrold, Fraser; Chami, George

2018-04-01

Perpendicular access to the posterolateral talar dome for the management of osteochondral defects is difficult. We examined exposure available from each of four surgical approaches. Four surgical approaches were performed on 9 Thiel-embalmed cadavers: anterolateral approach with arthrotomy; anterolateral approach with anterior talo-fibular ligament (ATFL) release; anterolateral approach with antero-lateral tibial osteotomy; and anterolateral approach with lateral malleolus osteotomy. The furthest distance posteriorly allowing perpendicular access with a 2mm k-wire was measured. An anterolateral approach with arthrotomy provided a mean exposure of the anterior third of the lateral talar dome. A lateral malleolus osteotomy provided superior exposure (81.5% vs 58.8%) compared to an anterolateral tibial osteotomy. Only the anterior half of the lateral border of the talar dome could be accessed with an anterolateral approach without osteotomy. A fibular osteotomy provided best exposure to the posterolateral aspect of the talar dome. Copyright © 2016 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Enduring perceptions: Place naming and the perception of Louisiana’s salt dome islands

Directory of Open Access Journals (Sweden)

Philip Hayward

2016-11-01

Full Text Available Salt domes are geological features that occur when areas of salt deposits are pressured into layers above them, causing dome shaped distortions in horizontal strata. In some instances, the distortions protrude above flat areas of land or else appear underwater as seamounts. In the case of the five Louisiana salt dome hills considered in this article, their distinct elevation above the swampy bayous and flatlands surrounding them has led to their characterisation as islands by indigenous Atakapa-Ishak peoples and by subsequent Francophone and Anglophone settlers. The article considers the ways in which the five salt domes’ islandness has been perceived, enhanced and/or undermined by various local inhabitants and/or the commercial operations that have operated on them. Discussion of these aspects involves consideration of the manner in which the salt dome islands’ islandness is mutable and complex, particularly with regard to human impacts. This mutability is discussed with regard to both individual island placenames and the islands’ overall designations.

A General Case to Determine Dimensions and Their Tolerance Zones for the Thread Parts of Epicyclic Roller-Screw Mechanisms

Directory of Open Access Journals (Sweden)

D. S. Blinov

2017-01-01

Full Text Available The most important trend in the development of aerospace industry is to increase load capacity of mechanisms, assemblies, and parts without increasing their size and weight. The above is also true for widely used in aircrafts and the most promising up to date Epicyclic Roller-Screw Mechanisms (ERSM that convert rotational movement into translational one. Previously (in the article, it was proposed to increase the load capacity (approximately by 15% through reduction of included angle of ERSM threaded parts from 90° to 70°.However, such improvement of ERSM will change dimensions of the mechanism parts and its parameters and characteristics (efficiency factor, position of initial point of contact of the conjugated thread turns and parameters of their contact interaction, as well as kinematic parameters, which will require additional studies. If we take into account the priority of these studies, then surely we must begin with development of technique to determine dimensions of the ERSM main parts and their tolerance zones because we need drawings to manufacture and test the upgraded ERSM. We have developed a technique to calculate dimensions of the main parts of ERSM and associated tolerance zones that takes in to account the change of included angle of threaded parts of the mechanism and radius of circular arc according to which roller thread profile has been fulfilled. So the proposed technique is the general one in comparison with the previous ones.This technique uses various conditions and equations to determine dimensions of parts and associated tolerance zones. For example, a nut encircles a screw with rollers, and their dimensions form a closed dimension chain, in which the dimensions and associated tolerances must be such as to ensure ERSM assembling, on the one hand, and, on the other hand the backlash of the mechanism should be minimal to ensure high load capacity, kinematic accuracy, and rigidity of ERSM. We used the following

The mythic structure in the black dome of the Haftpeikar: Study of Hero's journey in the first dome

Directory of Open Access Journals (Sweden)

Seyed Kazem Mousavi

2016-12-01

Full Text Available Abstract In this paper the Vogler Hero's journey is used for analyzing the mythic structures and hero's journey of the first dome of the Haftpeikar. Vogler Released his founds in the Writer's Journey book. This book that is really dependent on Campbell's Single Myth Theory is a practical guidance for script writing and review of that. The levels of the hero's journey in his book are include: The normal world, invitation to the story, reject the invitation, visit the mentor, passing the first gate, the exams, the allies, the enemies, qualifying to the deepest cave, trial, the reward, the road back, resurrection, return with the elixir.  In this paper, at first the properties of each level of the hero's journey theory are matching with the journey's levels in the black dome story. After that seven useful archetypes including hero, mentor, threshold guardian, herald, shape shifter, the shadow and trickster, are determined in the text.  Black dome has several journeys' cycles. Journey's that are seen in this dome are: (Bahram's journey: A part of the internal journey of Bahram in black dome. (The king's maid journey: Internal journey of the king's maid that wears black clothes after hearing the story. (King of black clothes' journey: The king's journey to the Madhooshan city for exploring the mystery of the black alien. (The reader's journey: This internal journey belongs to the readers of the first dome that learn their lessons through traveling to the character's world. (Nezami's journey: The Nezami's internal journey with composing the text. Checking the reader's journey and black dome's composer is out of this text. While the first and second journey just saying some parts, the black king has completer levels and for affecting on the other journeys is the most important story of the first dome. Therefore at first we check the black king story and we explain the other journeys.  The goal of this paper in addition to the usage of the vogler

Visual aesthetics study: Gibson Dome area, Paradox Basin, Utah

International Nuclear Information System (INIS)

1984-03-01

The Visual Aesthetics study was performed as an initial assessment of concerns regarding impacts to visual resources that might be associated with the construction of a geologic nuclear waste repository and associated rail routes in the Gibson Dome location of southeastern Utah. Potential impacts to visual resources were evaluated by predicting visibility of the facility and railway routes using the US Forest Service (USFS) computer program, VIEWIT, and by applying the Bureau of Land Management (BLM) Visual Resource Management (VRM) methodology. Five proposed facility sites in the Gibson Dome area and three proposed railway routes were evaluated for visual impact. 10 references, 19 figures, 5 tables

Long-Life, Oil-Free Polymeric, Multi-Roller Traction Drives for Planetary Vehicle Surface Exploration, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Multi-roller traction drives have several advantages relative to geared units for aerospace and commercial drive applications. Among these are zero backlash, low...

LA-ICP-MS and SIMS U-Pb and U-Th zircon geochronological data of Late Pleistocene lava domes of the Ciomadul Volcanic Dome Complex (Eastern Carpathians

Directory of Open Access Journals (Sweden)

Réka Lukács

2018-06-01

Full Text Available This article provides laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS and secondary ionization mass spectrometry (SIMS U-Pb and U-Th zircon dates for crystals separated from Late Pleistocene dacitic lava dome rocks of the Ciomadul Volcanic Dome Complex (Eastern Carpathians, Romania. The analyses were performed on unpolished zircon prism faces (termed rim analyses and on crystal interiors exposed through mechanical grinding an polishing (interior analyses. 206Pb/238U ages are corrected for Th-disequilibrium based on published and calculated distribution coefficients for U and Th using average whole-rock and individually analyzed zircon compositions. The data presented in this article were used for the Th-disequilibrium correction of (U-Th/He zircon geochronology data in the research article entitled “The onset of the volcanism in the Ciomadul Volcanic Dome Complex (Eastern Carpathians: eruption chronology and magma type variation” (Molnár et al., 2018 [1].

Percutaneous Ethanol Injection via an Artificially Induced Right Hydrothorax for Hepatocellular Carcinoma in the Hepatic Dome

International Nuclear Information System (INIS)

Kume, Akimichi; Nimura, Yuji; Kamiya, Junichi; Nagino, Masato; Kito, Yasushi

2003-01-01

To evaluate the efficacy of sonographically (US) guided percutaneous ethanol injection (PEI) via an artificially induced right hydrothorax (transthoracic PEI) to treat US-invisible hepatocellular carcinoma (HCC) in the hepatic dome. Five cirrhotic patients with US-invisible HCC in the hepatic dome, who were poor surgical candidates, underwent transthoracic PEI. An artificial right hydrothorax was created by instilling 500 ml saline, and absolute ethanol was injected transhydrothoracically into the hepatic dome lesion under local anesthesia. The success and complications were assessed radiologically. The patients were followed up serologically and radiologically for 12-44 (mean 28.4) months. Twenty-five hydrothoraces were induced. All hydrothoraces enabled US visualization of the entire hepatic dome. Eight of the nine small lesions were treated successfully by the treatment. Two of the three local recurrences were eradicated by repeat transthoracic PEI. One large lesion was treated by a combination of transthoracic and regular PEI. The only complication was one clinically insignificant pneumothorax. Induction of a right hydrothorax is feasible and safe. The hydrothorax enables US visualization of the entire hepatic dome and permits US-guided PEI for HCC in the hepatic dome that otherwise would not be possible

The selection of flying roller as an effort to increase the power of scooter-matic as the main power of centrifugal pump for fire fighter motor cycle

Science.gov (United States)

Hadi Sutrisno, Himawan

2018-03-01

In densely populated settlements, fires often occur and cause losses. In some instances, the process of the occurrence of fires takes place so quickly that to reduce and avoid the occurrence of a fire disaster effort is required in accordance with the existing environmental condition. Fire fighter motorcycle by using motorcycle scooter-matic is considered suitable as one alternative to combating fire hazard in densely populated residential settlements. The use of motorcycle engines as the driving force of the pump often leads to unstable and not optimum power. Thus, the water spray on the centrifugal pump also becomes not maximum. To increase the engine power at scooter-matic engine idle rotation (700-2000 rpm), then the flying roller replacement with certain mass weight becomes an option. By selecting a 10 to 14 gram flying roller mass, the power analysis using a dynotest engine produces several variations. Of the calculation, the mass of a 14 gram flying roller provides a significant increase in motor power on the upper rotation. Meanwhile, on the lower power rotation using a flying roller with a mass of 10 grams provides an increase in power compared to a standard flying roller on a scooter matic motor engine. As a reference to the use of scooter-matic motor power as the pump power, the result of use of the flying roller with a mass of 10 grams becomes the best option.

Kaguyak dome field and its Holocene caldera, Alaska Peninsula

Science.gov (United States)

Fierstein, J.; Hildreth, W.

2008-01-01

Kaguyak Caldera lies in a remote corner of Katmai National Park, 375??km SW of Anchorage, Alaska. The 2.5-by-3-km caldera collapsed ~ 5.8 ?? 0.2??ka (14C age) during emplacement of a radial apron of poorly pumiceous crystal-rich dacitic pyroclastic flows (61-67% SiO2). Proximal pumice-fall deposits are thin and sparsely preserved, but an oxidized coignimbrite ash is found as far as the Valley of Ten Thousand Smokes, 80??km southwest. Postcaldera events include filling the 150-m-deep caldera lake, emplacement of two intracaldera domes (61.5-64.5% SiO2), and phreatic ejection of lakefloor sediments onto the caldera rim. CO2 and H2S bubble up through the lake, weakly but widely. Geochemical analyses (n = 148), including pre-and post-caldera lavas (53-74% SiO2), define one of the lowest-K arc suites in Alaska. The precaldera edifice was not a stratocone but was, instead, nine contiguous but discrete clusters of lava domes, themselves stacks of rhyolite to basalt exogenous lobes and flows. Four extracaldera clusters are mid-to-late Pleistocene, but the other five are younger than 60??ka, were truncated by the collapse, and now make up the steep inner walls. The climactic ignimbrite was preceded by ~ 200??years by radial emplacement of a 100-m-thick sheet of block-rich glassy lava breccia (62-65.5% SiO2). Filling the notches between the truncated dome clusters, the breccia now makes up three segments of the steep caldera wall, which beheads gullies incised into the breccia deposit prior to caldera formation. They were probably shed by a large lava dome extruding where the lake is today.

An Analysis of US Emergency Department Visits From Falls From Skiing, Snowboarding, Skateboarding, Roller-Skating, and Using Nonmotorized Scooters.

Science.gov (United States)

Nathanson, Brian H; Ribeiro, Kara; Henneman, Philip L

2016-07-01

We analyzed the US incidence of emergency department (ED) visits and hospitalizations for falls from skiing, snowboarding, skateboarding, roller-skating, and nonmotorized scooters in 2011. The outcome was hospital admission from the ED. The primary analysis compared pediatric patients aged 1 to 17 years to adults aged 18 to 44 years. The analysis used ICD-9 E-codes E885.0 to E885.4 using discharge data from the Nationwide Emergency Department Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality. Approximately 214 000 ED visits met study criteria. Skiing injuries had the highest percentage of hospitalizations (3.30% in pediatric patients and 6.65% in adults 18-44 years old). Skateboard and snowboard injuries were more likely to require hospitalization than roller skating injuries in pediatric patients (odds ratio = 2.42; 95% CI = 2.14-2.75 and odds ratio = 1.83; 95% CI =1.55-2.15, respectively). In contrast, skateboard and snowboard injuries were less severe than roller-skating injuries in adults. © The Author(s) 2015.

Final report on decommissioning boreholes and wellsite restoration, Gulf Coast Interior Salt Domes of Mississippi

International Nuclear Information System (INIS)

1989-04-01

In 1978, eight salt domes in Texas, Louisiana, and Mississippi were identified for study as potential locations for a nuclear waste repository as part of the National Waste Terminal Storage (NWTS) program. Three domes were selected in Mississippi for ''area characterization'' phase study as follows: Lampton Dome near Columbia, Cypress Creek Dome near New Augusta, and Richton Dome near Richton. The purpose of the studies was to acquire geologic and geohydrologic information from shallow and deep drilling investigations to enable selection of sites suitable for more intensive study. Eleven deep well sites were selected for multiple-well installations to acquire information on the lithologic and hydraulic properties of regional aquifers. In 1986, the Gulf Coast salt domes were eliminated from further consideration for repository development by the selection of three candidate sites in other regions of the country. In 1987, well plugging and restoration of these deferred sites became a closeout activity. The primary objectives of this activity are to plug and abandon all wells and boreholes in accordance with state regulations, restore all drilling sites to as near original condition as feasible, and convey to landowners any wells on their property that they choose to maintain. This report describes the activities undertaken to accomplish these objectives, as outlines in Activity Plan 1--2, ''Activity Plan for Well Plugging and Site Restoration of Test Hole Sites in Mississippi.''

The thermo-mechanical behaviour of a salt dome with a heat-generating waste repository

International Nuclear Information System (INIS)

Janssen, L.G.J.; Prij, J.; Kevenaar, J.W.A.M.; Jong, C.J.T.; Klok, J.; Beemsterboer, C.

1984-01-01

This report reviews the analytical work on the disposal of radioactive waste in salt domes performed at ECN in the period 1 January 1980 to 31 December 1982. Chapter 4 in the main report covers the global temperature and deformation analyses of the salt dome and the surrounding rocks. The attached three topical reports cover self-contained parts of the study. The computer program TASTE developed to analyse, at acceptable cost and with, for engineering purposes, sufficient accuracies, the temperature rises in the salt dome due to the stored heat-generating waste is described in Annex 1. Annex 2 gives a description of the extended finite element program GOLIA. The program has been extended to make it suitable for the creep analysis of salt domes with repositories of heat-generating waste. The study on the closing and sealing of boreholes wit heat-generating waste is reported in Annex 3

BENDING THE DOMING EFFECT IN STRUCTURE FROM MOTION RECONSTRUCTIONS THROUGH BUNDLE ADJUSTMENT

Directory of Open Access Journals (Sweden)

L. Magri

2017-08-01

Full Text Available Structure from Motion techniques provides low-cost and flexible methods that can be adopted in arial surveying to collect topographic data with accurate results. Nevertheless, the so-called “doming effect”, due to unfortunate acquisition conditions or unreliable modeling of radial distortion, has been recognized as a critical issue that disrupts the quality of the attained 3D reconstruction. In this paper we propose a novel method, that works effectively in the presence of a nearly flat soil, to tackle a posteriori the doming effect: an automatic ground detection method is used to capture the doming deformation flawing the reconstruction, which in turn is wrapped to the correct geometry by iteratively enforcing a planarity constraint through a Bundle Adjustment framework. Experiments on real word datasets demonstrate promising results.

Computational modeling of lava domes using particle dynamics to investigate the effect of conduit flow mechanics on flow patterns

Science.gov (United States)

Husain, Taha Murtuza

Large (1--4 x 106 m3) to major (> 4 x 106 m3) dome collapses for andesitic lava domes such as Soufriere Hills Volcano, Montserrat are observed for elevated magma discharge rates (6--13 m3/s). The gas rich magma pulses lead to pressure build up in the lava dome that result in structural failure of the over steepened canyon-like walls which may lead to rockfall or pyroclastic flow. This indicates that dome collapse intimately related to magma extrusion rate. Variation in magma extrusion rate for open-system magma chambers is observed to follow alternating periods of high and low activity. Periodic behavior of magma exhibits a rich diversity in the nature of its eruptive history due to variation in magma chamber size, total crystal content, linear crystal growth rate and magma replenishment rate. Distinguished patterns of growth were observed at different magma flow rates ranging from endogenous to exogenous dome growth for magma with varying strengths. Determining the key parameters that control the transition in flow pattern of the magma during its lava dome building eruption is the main focus. This dissertation examines the mechanical effects on the morphology of the evolving lava dome on the extrusion of magma from a central vent using a 2D particle dynamics model. The particle dynamics model is coupled with a conduit flow model that incorporates the kinetics of crystallization and rheological stiffening to investigate important mechanisms during lava dome building eruptions. Chapter I of this dissertation explores lava dome growth and failure mechanics using a two-dimensional particle-dynamics model. The model follows the evolution of fractured lava, with solidification driven by degassing induced crystallization of magma. The particle-dynamics model emulates the natural development of dome growth and rearrangement of the lava dome which is difficult in mesh-based analyses due to mesh entanglement effects. The deformable talus evolves naturally as a frictional

Radiometric and ultrasonic testing of vibrating roller compacting effects

International Nuclear Information System (INIS)

Prikryl, F.; Habarta, J.; Kovarikova, E.

1977-01-01

A hole was filled with two layers of concrete mixture. Each layer was compacted using a Dynapac CA 25 vibrating roller 10,000 kg in weight, operating with a frequency of 30 Hz. A concrete block thus produced had dimensions of 11.0x2.5 m and a height of 1.6 m. After the concrete block hardening (roughly 120 days) drill cores were bored and bulk density was determined using nondestructive methods. Bulk density determination of the concrete between the drill cores was conducted using a 137 Cs emitter of an activity of 89 GBq, a FHZ-88b Geiger-Mueller counter was used as the detector. The emitter and detector were placed to touch the bore wall and were lowered to different depths in 10 cm increments. 10 count rate values were measured in each depth. The measurement time was chosen such that the decay statistical error did not exceed 1;. Bulk density of the individual segments of the drill cores was determined using 60 Co of an activitBy of 55 Mq as the radiation source and a TESLA 20/100 GWl GM counter as the detector. The detector operating voltage was 1240 V. Ultrasonic measurements were conducted using the USME-5 instrument. The measured bulk density values show that the compacting of a concrete layer 80 cm in thickness using a vibrating roller is sufficiently efficient. Both nondestructive methods were well proven, the results show that bulk density values in different depths differ due to concrete moisture content. (J.P.)

Volcano dome dynamics at Mount St. Helens: Deformation and intermittent subsidence monitored by seismicity and camera imagery pixel offsets

Science.gov (United States)

Salzer, Jacqueline T.; Thelen, Weston A.; James, Mike R.; Walter, Thomas R.; Moran, Seth C.; Denlinger, Roger P.

2016-01-01

The surface deformation field measured at volcanic domes provides insights into the effects of magmatic processes, gravity- and gas-driven processes, and the development and distribution of internal dome structures. Here we study short-term dome deformation associated with earthquakes at Mount St. Helens, recorded by a permanent optical camera and seismic monitoring network. We use Digital Image Correlation (DIC) to compute the displacement field between successive images and compare the results to the occurrence and characteristics of seismic events during a 6 week period of dome growth in 2006. The results reveal that dome growth at Mount St. Helens was repeatedly interrupted by short-term meter-scale downward displacements at the dome surface, which were associated in time with low-frequency, large-magnitude seismic events followed by a tremor-like signal. The tremor was only recorded by the seismic stations closest to the dome. We find a correlation between the magnitudes of the camera-derived displacements and the spectral amplitudes of the associated tremor. We use the DIC results from two cameras and a high-resolution topographic model to derive full 3-D displacement maps, which reveals internal dome structures and the effect of the seismic activity on daily surface velocities. We postulate that the tremor is recording the gravity-driven response of the upper dome due to mechanical collapse or depressurization and fault-controlled slumping. Our results highlight the different scales and structural expressions during growth and disintegration of lava domes and the relationships between seismic and deformation signals.

Axisymmetric modeling of prestressing tendons in nuclear containment dome

Energy Technology Data Exchange (ETDEWEB)

Jeon, Se-Jin [DAEWOO E and C, Institute of Construction Technology, 60 Songjook-dong, Jangan-gu, Suwon, Kyonggi 440-210 (Korea, Republic of)]. E-mail: jsj@dwconst.co.kr; Chung, Chul-Hun [Department of Civil and Environmental Engineering, Dankook University, San 8, Hannam-dong, Youngsan-gu, Seoul 140-714 (Korea, Republic of)

2005-12-15

Simple axisymmetric modeling of a nuclear containment building has been often employed in practice to estimate structural behavior for the axisymmetric loadings such as internal pressure. In this case, the prestressing tendons placed in the containment dome should be axisymmetrically approximated, since most dome tendons are not arranged in an axisymmetric manner. Some procedures are proposed that can realistically implement the actual three-dimensional tendon stiffness and prestressing effect into the axisymmetric model. Prestressing tendons, which are arranged in two or three ways depending on a containment type, are converted into the equivalent layer to consider the stiffness contribution in meridional and hoop directions. In order to reflect the prestressing effect, the equivalent load method and the initial stress method are devised, respectively, and the corresponding loads or stresses are derived in terms of the axisymmetric model. The proposed schemes are verified through some numerical examples comparing the results of the axisymmetric models to those of the actual three-dimensional model. The examples show that the proper level of the prestressing in the hoop direction of the axisymmetric dome plays an important role in tracing the actual behavior induced by the prestressing. Finally, some correction factors are discussed that can further improve the analysis results.

Axisymmetric modeling of prestressing tendons in nuclear containment dome

International Nuclear Information System (INIS)

Jeon, Se-Jin; Chung, Chul-Hun

2005-01-01

Simple axisymmetric modeling of a nuclear containment building has been often employed in practice to estimate structural behavior for the axisymmetric loadings such as internal pressure. In this case, the prestressing tendons placed in the containment dome should be axisymmetrically approximated, since most dome tendons are not arranged in an axisymmetric manner. Some procedures are proposed that can realistically implement the actual three-dimensional tendon stiffness and prestressing effect into the axisymmetric model. Prestressing tendons, which are arranged in two or three ways depending on a containment type, are converted into the equivalent layer to consider the stiffness contribution in meridional and hoop directions. In order to reflect the prestressing effect, the equivalent load method and the initial stress method are devised, respectively, and the corresponding loads or stresses are derived in terms of the axisymmetric model. The proposed schemes are verified through some numerical examples comparing the results of the axisymmetric models to those of the actual three-dimensional model. The examples show that the proper level of the prestressing in the hoop direction of the axisymmetric dome plays an important role in tracing the actual behavior induced by the prestressing. Finally, some correction factors are discussed that can further improve the analysis results

Volcano-tectonic control of Merapi's lava dome splitting observed from high resolution TerraSAR-X data

KAUST Repository

Luehr, Birger-G.; Walter, Thomas R.; Subandriyo, Joko; Sri Brotopuspito, Kirbani; Vasyura-Bathke, Hannes; Suryanto, Wiwit; Aisyah, Naning; Darmawan, Herlan; Nikkhoo, Mehdi; Richter, Nicole; Jousset, Philippe; Dahm, Torsten

2015-01-01

Volcanism at active andesite-dacite volcanoes is often associated with the formation and collapse of circular shaped protrusions of extruded, highly viscous lava, the so-called domes, which are emplaced in the near summit region. Growing domes may experience stable and instable structural phases, with a gradual transition in between. Dome collapse and the break-off of instable blocks of viscous lava may lead to pyroclastic flows, one of the most lethal hazards at stratovolcanoes. At Merapi volcano, Indonesia, nearly 50 % of all eruptions are accompanied by these phenomena. After the climactic eruption in 2010 which left an amphitheater in the summit region, a new dome started growing. Three years later, the dome reached a height of approximately 100 m and diameters of 220 and 190 m with a plateau-like surface area of 40,000m2 approximately. On 18/11/2013, an explosion occurred without identified precursors, leaving a major fracture cutting the complete dome structure. Based on high resolution TerraSAR-X satellite radar imagery, we could identify this linear fracture, traceable over ~200m in the long axis, and up to 40m width. After geocoding of the radar amplitude imagery, the fractures azimuthal trend could be compared to other structural lineaments, indicative of a significant NNW-SSE structural direction that has formed on Merapi volcano in the past. This alignment is also visible in a seismic velocity tomographic imagery for the upper crust, down to 15 km depth. The Merapi dome fractured in a NW-SE direction, and is consistent with the alignment of regional tectonic structures and of anticipated directions of pyroclastic flows. The fracture may be part of a larger volcano-tectonic system and may affect the dynamics and the stability of the Merapi dome.

Volcano-tectonic control of Merapi's lava dome splitting observed from high resolution TerraSAR-X data

KAUST Repository

Luehr, Birger-G.

2015-04-01

Volcanism at active andesite-dacite volcanoes is often associated with the formation and collapse of circular shaped protrusions of extruded, highly viscous lava, the so-called domes, which are emplaced in the near summit region. Growing domes may experience stable and instable structural phases, with a gradual transition in between. Dome collapse and the break-off of instable blocks of viscous lava may lead to pyroclastic flows, one of the most lethal hazards at stratovolcanoes. At Merapi volcano, Indonesia, nearly 50 % of all eruptions are accompanied by these phenomena. After the climactic eruption in 2010 which left an amphitheater in the summit region, a new dome started growing. Three years later, the dome reached a height of approximately 100 m and diameters of 220 and 190 m with a plateau-like surface area of 40,000m2 approximately. On 18/11/2013, an explosion occurred without identified precursors, leaving a major fracture cutting the complete dome structure. Based on high resolution TerraSAR-X satellite radar imagery, we could identify this linear fracture, traceable over ~200m in the long axis, and up to 40m width. After geocoding of the radar amplitude imagery, the fractures azimuthal trend could be compared to other structural lineaments, indicative of a significant NNW-SSE structural direction that has formed on Merapi volcano in the past. This alignment is also visible in a seismic velocity tomographic imagery for the upper crust, down to 15 km depth. The Merapi dome fractured in a NW-SE direction, and is consistent with the alignment of regional tectonic structures and of anticipated directions of pyroclastic flows. The fracture may be part of a larger volcano-tectonic system and may affect the dynamics and the stability of the Merapi dome.

Significant changes in the skin microbiome mediated by the sport of roller derby

Directory of Open Access Journals (Sweden)

James F. Meadow

2013-03-01

Full Text Available Diverse bacterial communities live on and in human skin. These complex communities vary by skin location on the body, over time, between individuals, and between geographic regions. Culture-based studies have shown that human to human and human to surface contact mediates the dispersal of pathogens, yet little is currently known about the drivers of bacterial community assembly patterns on human skin. We hypothesized that participation in a sport involving skin to skin contact would result in detectable shifts in skin bacterial community composition. We conducted a study during a flat track roller derby tournament, and found that teammates shared distinct skin microbial communities before and after playing against another team, but that opposing teams’ bacterial communities converged during the course of a roller derby bout. Our results are consistent with the hypothesis that the human skin microbiome shifts in composition during activities involving human to human contact, and that contact sports provide an ideal setting in which to evaluate dispersal of microorganisms between people.

NW Africa post-rift tectonics: fieldwork constraints from an "unfitting" anticline in west Morocco

Science.gov (United States)

Fernández-Blanco, David; Gouiza, Mohamed

2015-04-01

The evolution of the Moroccan Atlantic rifted margin is marked by a period of abnormal and excessive early post-rift subsidence during the Late Jurassic-Early Cretaceous affecting the proximal coastal basins, the continental shelf and the distal deep basins, which acted coevally to km-scale uplift and erosion of large domains to the east. The tectonics of the uplift event are still unclear, as it took place 30 to 50 Myr after lithospheric breakup between Morocco and Nova Scotia and prior to the Atlas/Alpine contraction, which gave rise to the Atlas and the Rif mountain belts. The Essaouira-Haha basin, located on the coastal plain of the Atlantic rifted margin of Morocco, and bounded by two uplifted Paleozoic basement highs (i.e. the Massif Ancien of Marrakech, to the east, and the Jebilet, to the northeast), is an ideal location to investigate the tectonic processes that might have triggered these vertical movements. Although most of the deformation observed in the basin is classically attributed to Upper Cretaceous halokinesis and Neogene Atlas contraction, recent works have shown the existence of contractional structures. We carry out a structural analysis of the Jbel Amsittene Anticline, located in the middle of the Essaouira-Haha basin to investigate the tectonics of its formation and its relationship with the above-mentioned exhumation. We show structural field data along several cross-sections transecting the anticline, and characterize a salt-cored fault propagation fold verging north, with a Triassic salt acting as a detachment plane. Regional kinematic indicators and structures show overall NNW-SSE to NNE-SSW shortening and active tectonics during the postrift phase, as indicated by syn-tectonic wedges seen for the Late Jurassic to Early Cretaceous period. These facts discard the "salt-drives-tectonics" theory to let "tectonic-drives-salt" one to rise, and point to factors other than small-cell mantle convection acting during the evolution of the Moroccan

Influence of conduit flow mechanics on magma rheology and the growth style of lava domes

Science.gov (United States)

Husain, Taha; Elsworth, Derek; Voight, Barry; Mattioli, Glen; Jansma, Pamela

2018-06-01

We develop a 2-D particle-mechanics model to explore different lava-dome growth styles. These range from endogenous lava dome growth comprising expansion of a ductile dome core to the exogenous extrusion of a degassed lava plug resulting in generation of a lava spine. We couple conduit flow dynamics with surface growth of the evolving lava dome, fuelled by an open-system magma chamber undergoing continuous replenishment. The conduit flow model accounts for the variation in rheology of ascending magma that results from degassing-induced crystallization. A period of reduced effusive flow rates promote enhanced degassing-induced crystallization. A degassed lava plug extrudes exogenously for magmas with crystal contents (ϕ) of 78 per cent, yield strength >1.62 MPa, and at flow rates of 3 m3 s-1) for magma with lower relative yield strengths (p = 3 MPa) at the conduit exit is forced out by the high discharge rate pulse (2 process, which has been observed at Mount St. Helens and other locations, largely reflects gravitational loading of dome with a viscous core, with retardation by yield strength and talus friction.

Hot Ductility Behavior of an 8 Pct Cr Roller Steel

Science.gov (United States)

Wang, Zhenhua; Sun, Shuhua; Shi, Zhongping; Wang, Bo; Fu, Wantang

2015-04-01

The hot ductility of an 8 pct Cr roller steel was determined between 1173 K and 1473 K (900 °C and 1200 °C) at strain rates of 0.01 to 10 s-1 through tensile testing. The fracture morphology was observed using scanning electron microscopy, and the microstructure was examined through optical microscopy and transmission electron microscopy. The dependence of the hot ductility behavior on the deformation conditions, grain size, and precipitation was analyzed. The relationship between the reduction in area and the natural logarithm of the Zener-Hollomon parameter (ln Z) was found to be a second-order polynomial. When ln Z was greater than 40 s-1, the hot ductility was poor and fracture was mainly caused by incompatible deformation between the grains. When ln Z was between 32 and 40 s-1, the hot ductility was excellent and the main fracture mechanism was void linking. When ln Z was below 32 s-1, the hot ductility was poor and fracture was mainly caused by grain boundary sliding. A fine grain structure is beneficial for homogenous deformation and dynamic recrystallization, which induces better hot ductility. The effect of M7C3 carbide particles dispersed in the matrix on the hot ductility was small. The grain growth kinetics in the 8 pct Cr steel were obtained between 1373 K and 1473 K (1100 °C and 1200 °C). Finally, optimized preheating and forging procedures for 8 pct Cr steel rollers are provided.

Dome-shaped macula associated with Best vitelliform macular dystrophy.

Science.gov (United States)

Battaglia Parodi, Maurizio; Zucchiatti, Ilaria; Fasce, Francesco; Cascavilla, Maria Lucia; Cicinelli, Maria Vittoria; Bandello, Francesco

2015-01-01

Dome-shaped macula (DSM) has been described recently as an inward convexity of the macula typical of myopic eyes detectable on spectral-domain optical coherence tomography (SD-OCT). The authors describe a case of monolateral DSM associated with Best vitelliform macular dystrophy (VMD). Case report. A 60-year-old man already diagnosed with VMD in vitelliruptive stage underwent SD-OCT that revealed the typical vitelliform material accumulation associated in the left eye with a convex elevation of the macula. No change was registered over a 1-year follow-up. This is the first report describing a monolateral DSM associated with VMD. Dome-shaped macula could be considered as a nonspecific scleral alteration, probably due to increased scleral thickness, which can accompany many retinal disorders.

DOME-SHAPED MACULA WITH THICKENED CHOROID IN AN EMMETROPIC PATIENT.

Science.gov (United States)

Kedkovid, Napang; Afshar, Armin R; Damato, Bertil E; Stewart, Jay M

2015-01-01

To report a rare case of bilateral dome-shaped macula in an emmetropic patient. Clinical case report and literature review. A 42-year-old woman presented with a history of blurred vision in the right eye. Visual acuity was 20/30 in the right eye and 20/20 in the left eye. Intraocular pressure and anterior segment were unremarkable. Fundus examination revealed dull macular reflex and subretinal fluid nasal to the fovea in the right eye and a hyperpigmented area inferotemporal to the fovea in the left eye. Spectral domain optical coherence tomography showed subretinal fluid under the fovea in the right eye and elevation of the macula with increased choroidal thickness in both eyes. Fluorescein angiography revealed abnormal hyperfluorescence without any leakage in both eyes. B-scan ultrasound showed irregular globe contour with high internal reflectivity and dome-shaped lesions at the posterior pole in both eyes. Axial length was 24.6 mm in the right eye and 25.6 mm in the left eye. Although most commonly reported in myopic eyes, dome-shaped macula can occur in an emmetropic patient and can be associated with subretinal fluid.

Regional Jurassic geologic framework of Alabama coastal waters area and adjacent Federal waters area

Science.gov (United States)

Mink, R.M.; Bearden, B.L.; Mancini, E.A.

1989-01-01

To date, numerous Jurassic hydrocarbon fields and pools have been discovered in the Cotton Valley Group, Haynesville Formation, Smackover Formation and Norphlet Formation in the tri-state area of Mississippi, Alabama and Florida, and in Alabama State coastal waters and adjacent Federal waters area. Petroleum traps are basement highs, salt anticlines, faulted salt anticlines and extensional faults associated with salt movement. Reservoirs include continental and marine sandstones, limestones and dolostones. Hydrocarbon types are oil, condensate and natural gas. The onshore stratigraphic and structural information can be used to establish a regional geologic framework for the Jurassic for the State coastal waters and adjacent Federal waters areas. Evaluation of the geologic information along with the hydrocarbon data from the tri-state area indicates that at least three Jurassic hydrocarbon trends (oil, oil and gas condensate, and deep natural gas) can be identified onshore. These onshore hydrocarbon trends can be projected into the Mobile area in the Central Gulf of Mexico and into the Pensacola, Destin Dome and Apalachicola areas in the Eastern Gulf of Mexico. Substantial reserves of natural gas are expected to be present in Alabama State waters and the northern portion of the Mobile area. Significant accumulations of oil and gas condensate may be encountered in the Pensacola, Destin Dome, and Apalachicola areas. ?? 1989.

A Case Study of the Vredefort Dome

African Journals Online (AJOL)

South Africa became a signatory to and ratified the World Heritage Convention, 1972 (WHC) in 1997. It thereby voluntarily agreed to identify and conserve world heritage areas of universal value for the benefit of mankind. This article presents a case study of the Vredefort Dome, one of South Africa\\'s World Heritage Sites ...

Where is the Best Site on Earth? Domes A, B, C, and F, and Ridges A and B

Science.gov (United States)

Suanders, Will; Lawrence, Jon S.; Storey, John W. V.; Ashley, Michael C. B.; Kato, Seiji; Minnis, Patrick; Winker, David M.; Liu, Guiping; Kulesa, Craig

2009-01-01

The Antarctic plateau contains the best sites on earth for many forms of astronomy, but none of the existing bases were selected with astronomy as the primary motivation. In this paper, we try to systematically compare the merits of potential observatory sites. We include South Pole, Domes A, C and F, and also Ridge B (running NE from Dome A), and what we call Ridge A (running SW from Dome A). Our analysis combines satellite data, published results and atmospheric models, to compare the boundary layer, weather, free atmosphere, sky brightness, pecipitable water vapour, and surface temperature at each site. We find that all Antarctic sites are likely compromised for optical work by airglow and aurorae. Of the sites with existing bases, Dome A is the best overall; but we find that Ridge A offers an even better site. We also find that Dome F is a remarkably good site. Dome C is less good as a thermal infrared or terahertz site, but would be able to take advantage of a predicted OH hole over Antarctica during Spring.

Enhanced depth imaging optical coherence tomography of the sclera in dome-shaped macula.

Science.gov (United States)

Imamura, Yutaka; Iida, Tomohiro; Maruko, Ichiro; Zweifel, Sandrine A; Spaide, Richard F

2011-02-01

To examine the posterior anatomic structure of eyes with dome-shaped macula using enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT). Retrospective observational case series. Patients with dome-shaped macula, a condition defined as convex elevation of the macula as compared with the surrounding staphylomatous region in a highly myopic eye, were identified through routine examinations using optical coherence tomography (OCT). EDI-OCT was used to examine their posterior anatomic changes. The scleral thickness was measured from the outer border of the choroid to the outer scleral border under the fovea and 3000 μm temporal to the fovea. The mean age of the 15 patients (23 eyes) was 59.3 (± 12.2) years, and the mean refractive error was -13.6 (± 5.0) diopters. The best-corrected visual acuity ranged from 20/15 to 20/800 (median: 20/30). Eight patients (53%) had dome-shaped macula bilaterally. The mean subfoveal scleral thickness in 23 eyes with dome-shaped macula was 570 (± 221) μm, and that in 25 eyes of 15 myopic patients with staphyloma but without dome-shaped macula was 281 (± 85) μm (P macula is the result of a relative localized thickness variation of the sclera under the macula in highly myopic patients, and it cannot be categorized into any of the known types of staphyloma. This finding suggests the ocular expansion in myopia may be more complex than previously thought. Copyright © 2011 Elsevier Inc. All rights reserved.

Control rod upper pin and roller removal and replacement

International Nuclear Information System (INIS)

Giordano, B.

1995-01-01

There has been increasing utility interest in removing cobalt sources as a means to minimize dose rates and shipping costs associated with operations, maintenance, shipping and radioactive waste disposal. This activation product accounts for approximately 80% of the dose rates at a plant. Estimates suggest that older (original equipment) control rod blades (CRBs) using stellite rollers and Haynes Alloy 25 pins can contribute as much as 43% of the cobalt in the plant. Since CRBs are the most concentrated source of cobalt in the reactor vessel, pin and roller (P ampersand R) replacement will provide significant reductions in cobalt-60 levels. The reductions will be measurable within 2 years, and should plateau within 5 to 6 years. This paper described a new, simple, cost effective, field proven in-situ method to replace these high source term contributing components and return the CRB to the reactor core for continued service. The paper also briefly describes a methodology that has been developed to estimate the labor and material costs along with a man-rem dollar savings for removal of the upper P ampersand Rs from in-service CRBs purchased prior to 1982. This method permits comparison to the cost of early replacement of CRBs. The result of this study is an EXCEL spreadsheet cost/benefit analysis that can be made plant specific by incorporation of plant data. The Analysis shows that the removal of P ampersand Rs can be beneficial for a Co-60 contribution as low as 5-10%. Recent interest by non-utility radioactive material users in obtaining the removed P ampersand Rs may further increase the benefit and reduce the cost associated with in-situ removal

A Sparsity-Promoted Decomposition for Compressed Fault Diagnosis of Roller Bearings

Directory of Open Access Journals (Sweden)

Huaqing Wang

2016-09-01

Full Text Available The traditional approaches for condition monitoring of roller bearings are almost always achieved under Shannon sampling theorem conditions, leading to a big-data problem. The compressed sensing (CS theory provides a new solution to the big-data problem. However, the vibration signals are insufficiently sparse and it is difficult to achieve sparsity using the conventional techniques, which impedes the application of CS theory. Therefore, it is of great significance to promote the sparsity when applying the CS theory to fault diagnosis of roller bearings. To increase the sparsity of vibration signals, a sparsity-promoted method called the tunable Q-factor wavelet transform based on decomposing the analyzed signals into transient impact components and high oscillation components is utilized in this work. The former become sparser than the raw signals with noise eliminated, whereas the latter include noise. Thus, the decomposed transient impact components replace the original signals for analysis. The CS theory is applied to extract the fault features without complete reconstruction, which means that the reconstruction can be completed when the components with interested frequencies are detected and the fault diagnosis can be achieved during the reconstruction procedure. The application cases prove that the CS theory assisted by the tunable Q-factor wavelet transform can successfully extract the fault features from the compressed samples.

Modeling of contact theories for the manipulation of biological micro/nanoparticles in the form of circular crowned rollers based on the atomic force microscope

International Nuclear Information System (INIS)

Korayem, M. H.; Khaksar, H.; Taheri, M.

2013-01-01

This article has dealt with the development and modeling of various contact theories for biological nanoparticles shaped as cylinders and circular crowned rollers for application in the manipulation of different biological micro/nanoparticles based on Atomic Force Microscope. First, the effective contact forces were simulated, and their impact on contact mechanics simulation was investigated. In the next step, the Hertz contact model was simulated and compared for gold and DNA nanoparticles with the three types of spherical, cylindrical, and circular crowned roller type contact geometries. Then by reducing the length of the cylindrical section in the circular crowned roller geometry, the geometry of the body was made to approach that of a sphere, and the results were compared for DNA nanoparticles. To anticipatory validate the developed theories, the results of the cylindrical and the circular crowned roller contacts were compared with the results of the existing spherical contact simulations. Following the development of these contact models for the manipulation of various biological micro/nanoparticles, the cylindrical and the circular crowned roller type contact theories were modeled based on the theories of Lundberg, Dowson, Nikpur, Heoprich, and Hertz for the manipulation of biological micro/nanoparticles. Then, for a more accurate validation, the results obtained from the simulations were compared with those obtained by the finite element method and with the experimental results available in previous articles. The previous research works on the simulation of nanomanipulation have mainly investigated the contact theories used in the manipulation of spherical micro/nanoparticles. However since in real biomanipulation situations, biological micro/nanoparticles of more complex shapes need to be displaced in biological environments, this article therefore has modeled and compared, for the first time, different contact theories for use in the biomanipulation of

Disposal of high-level waste from nuclear power plants in Denmark. Salt dome investigations. v.5

International Nuclear Information System (INIS)

1981-01-01

The present report deals with safety evaluation as part of the investigations regarding a repository for high-level waste in a salt dome. It is volume 5 of five volumes that together constitute the final report on the Danish utilities' salt dome investigations. Two characteristics of the waste are of special importance for the safety evaluation: the encasing of the waste in steel casks with 15 cm thick walls affording protection against corrosion, protecting the surroundings against radiation, and protecting the glass cylinders from mechanical damage resulting from the pressure at the bottom of the disposal hole, and the modest generation of heat in the waste at the time of disposal resulting in a maximum temperature increase in the salt close to the waste of approx. 40 deg. C. These characteristics proved to considerably improve the safety margin with respect to unforeseen circumstances. The character of the salt dome and of the salt in the proposed disposal area offers in itself good protection against contact with the ground water outside the dome. The relatively large depth of 1200 and 2500 m of the salt surface also means that neither dome nor disposal facility will be appreciably influenced by glaciations or earthquakes. The chalk above the proposed disposal area is very tight and to retain radioactive matter effectively even in the precence of high concentrations of NaCL. The safety investigations included a number of natural processes and probable events such as the segregation of crystal water from overlooked salt minerals, faulty sealings of disposal holes, permeable fault zones in the chalk overlying the dome, the risk in connection with human penetration into the dome. These conditions will neither lead to the destruction of the waste casks or to the release of waste from the dome. Leaching of a cavern is the only situation which proved to result in a release of radioactive material to the biosphere, but the resulting doses was found to be small

Corrosion investigation of material combinations in a mobile phone dome-key pad system

DEFF Research Database (Denmark)

Ambat, Rajan; Møller, Per

2007-01-01

to multiple corrosion problems. In this paper, the corrosion susceptibility of dome (Ag/AISI 202 steel) and key pad system (Au/Ni/Cu) is investigated with an aim to understand the corrosion performance of such multi-material combinations in chloride containing environment. Investigation includes...... microstructural studies, polarization measurements using microelectrochemical technique, salt spray testing, and corrosion morphology analysis. The immersion Au layer on pads showed pores, and rolled bonded silver layer on dome had cracks and kinks. The difference in electrochemical behaviour of the metallic...... layers together with imperfections in the top layer results in severe pitting due to galvanic coupling. However, corrosion performance of the pads was much worse than domes. The results are applicable to a broad spectrum of PCB parts where similar material combinations are employed, especially Au/Ni/Cu....

Acute, fatal Sarcocystis calchasi-associated hepatitis in Roller pigeons (Columbia livia f. dom.) at Philadelphia Zoo

Science.gov (United States)

Four Roller pigeons (Columba livia f. dom.) at the Philadelphia Zoo died suddenly. Necropsy examination revealed macroscopic hepatitis. Microscopically, the predominant lesions were in liver, characterized with necrosis and mixed cell inflammatory response. Sarcocystis calchasi-like schizonts and fr...

Roller Bearing Monitoring by New Subspace-Based Damage Indicator

Directory of Open Access Journals (Sweden)

G. Gautier

2015-01-01

Full Text Available A frequency-band subspace-based damage identification method for fault diagnosis in roller bearings is presented. Subspace-based damage indicators are obtained by filtering the vibration data in the frequency range where damage is likely to occur, that is, around the bearing characteristic frequencies. The proposed method is validated by considering simulated data of a damaged bearing. Also, an experimental case is considered which focuses on collecting the vibration data issued from a run-to-failure test. It is shown that the proposed method can detect bearing defects and, as such, it appears to be an efficient tool for diagnosis purpose.

Dual Innervation of Neonatal Merkel Cells in Mouse Touch Domes

Science.gov (United States)

Luo, Wenqin

2014-01-01

Merkel cell-neurite complexes are specialized mechanosensory end organs that mediate discriminative touch sensation. It is well established that type I slowly adapting (SAI) mechanoreceptors, which express neural filament heavy chain (NFH), innervate Merkel cells. It was previously shown that neurotrophic factor NT3 and its receptor TrkC play crucial roles in controlling touch dome Merkel cell innervation of NFH+ fibers. In addition, nerve fibers expressing another neurotrophic tyrosine receptor kinase (NTRK), Ret, innervate touch dome Merkel cells as well. However, the relationship between afferents responsive to NT3/TrkC signaling and those expressing Ret is unclear. It is also controversial if these Ret+ fibers belong to the early or late Ret+ DRG neurons, which are defined based on the co-expression and developmental dependence of TrkA. To address these questions, we genetically traced Ret+ and TrkC+ fibers and analyzed their developmental dependence on TrkA. We found that Merkel cells in neonatal mouse touch domes receive innervation of two types of fibers: one group is Ret+, while the other subset expresses TrkC and NFH. In addition, Ret+ fibers depend on TrkA for their survival and normal innervation whereas NFH+ Merkel cell innervating fibers are almost unaltered in TrkA mutant mice, supporting that Ret+ and NFH+/TrkC+ afferents are two distinct groups. Ret signaling, on the other hand, plays a minor role for the innervation of neonatal touch domes. In contrast, Merkel cells in the glabrous skin are mainly contacted by NFH+/TrkC+ afferents. Taken together, our results suggest that neonatal Merkel cells around hair follicles receive dual innervation while Merkel cells in the glabrous skin are mainly innervated by only SAI mechanoreceptors. In addition, our results suggest that neonatal Ret+ Merkel cell innervating fibers most likely belong to the late but not early Ret+ DRG neurons. PMID:24637732

Regional sulfate-hematite-sulfide zoning in the auriferous Mariana anticline, Quadrilátero Ferrífero of Minas Gerais, Brazil

Science.gov (United States)

Cabral, Alexandre Raphael; Koglin, Nikola; Strauss, Harald; Brätz, Helene; Kwitko-Ribeiro, Rogerio

2013-10-01

The distribution of mineral deposits, characterised as barite deposits, hematite-rich auriferous deposits and auriferous tourmaline-sulfide deposits, displays a regional sulfate-hematite-sulfide zoning along the thrust-delineated limbs of the Mariana anticline, in the south-eastern part of the Quadrilátero Ferrífero of Minas Gerais, Brazil. Cross-cut relationships of barite veins and sulfide lodes indicate that sulfidation occurred in a late-tectonic context, which is here attributed to the collapse of the ˜0.6-Ga Brasiliano thrust front. Reconnaissance S-isotopic data from barite and pyrite (Antônio Pereira barite deposit and its adjacent gold deposit, respectively), and arsenopyrite (Passagem de Mariana gold deposit), suggest a new interpretation for the hydrothermal fluid overprint in the Mariana anticline. The Antônio Pereira barite has Δ33S values that are near zero, constraining the sulfate source to rocks younger than 2.45 Ga. The barite-δ34S values are between +19.6 and +20.8 ‰. The Passagem arsenopyrite and tourmaline have Co/Ni ratios that define a positive linear trend with the Antônio Pereira pyrite. The latter has homogenous δ34S values, between +8.8 and +8.9 ‰, which are compatible with thermochemical reduction of aqueous sulfate with the S-isotopic composition of the Antônio Pereira barite.

Influence of extrusion rate and magma rheology on the growth of lava domes: Insights from particle-dynamics modeling

Science.gov (United States)

Husain, Taha; Elsworth, Derek; Voight, Barry; Mattioli, Glen; Jansma, Pamela

2014-09-01

Lava domes are structures that grow by the extrusion of viscous silicic or intermediate composition magma from a central volcanic conduit. Repeated cycles of growth are punctuated by collapse, as the structure becomes oversized for the strength of the composite magma that rheologically stiffens and strengthens at its surface. Here we explore lava dome growth and failure mechanics using a two-dimensional particle-dynamics model. The model follows the evolution of fractured lava, with solidification driven by degassing induced crystallization of magma. The particle-dynamics model emulates the natural development of dome growth and rearrangement of the lava dome which is difficult in mesh-based analyses due to mesh entanglement effects. The deformable talus evolves naturally as a frictional carapace that caps a ductile magma core. Extrusion rate and magma rheology together with crystallization temperature and volatile content govern the distribution of strength in the composite structure. This new model is calibrated against existing observational models of lava dome growth. Results show that the shape and extent of the ductile core and the overall structure of the lava dome are strongly controlled by the infusion rate. The effects of extrusion rate on magma rheology are sensitive to material stiffness, which in turn is a function of volatile content and crystallinity. Material stiffness and material strength are key model parameters which govern magma rheology and subsequently the morphological character of the lava dome and in turn stability. Degassing induced crystallization causes material stiffening and enhances material strength reflected in non-Newtonian magma behavior. The increase in stiffness and strength of the injected magma causes a transition in the style of dome growth, from endogenous expansion of a ductile core, to stiffer and stronger intruding material capable of punching through the overlying material and resulting in the development of a spine or

Biostratigraphy and sequence stratigraphy of the Sarvak Formation at Fahliyan Anticline (South of Yasuj)

International Nuclear Information System (INIS)

Ahmadi, A.; Vaziri-Moghaddam, A.; Sayrafian, A.; Taheri, A.

2016-01-01

In this study, bio stratigraphy, depositional environment and sequence stratigraphy of the Sarvak Formation at Fahliyan Anticline was studied. 8 species of benthic foraminifera (4 genera) and 8 species of planktonic foraminifera (11 genera) in the study area were recognized. 6 biozones have been recognized by distribution of the foraminifera, which in stratigraphic order are: Favusella washitensis Zone, Orbitolina-Alveolinids Assemblage Zone, Rudist debris Zone, Oligostegina flood Zone, Whiteinella archaeocretacea Zone and Helvetoglobotruncana helvetica Zone. On the basis of these, the age of Albian–Turonian was considered for the Sarvak Formation. Based on petrography and analysis of microfacies features 9 different microfacies types have been recognized, which can be grouped into 3 depositional environments: lagoon, shoal and open marine. The Sarvak Formation represents sedimentation on a carbonate ramp. Sequence stratigraphy analysis led to identification of 4 third-order sequences.

The effect of extrusion and drying on roller techniques concerning the rheological characteristics of rice-, corn-, sweet potato-, bean- and cassava root- and leaf- based composite flour

Directory of Open Access Journals (Sweden)

Johanna Aristizábal Galvis

2013-01-01

Full Text Available Promoting food security in Latin-America and the Caribbean is directly related to agricultural products. The region faces a food crisis which has reduced large population groups’ access to food. This work contributes to the study of obtaining precooked composite flour made from biofortified crops using protein, vitamin A and/or minerals. This study evaluated the effect of precooked flour’s composition and precooking on its solubility in water, water absorption capacity, consistency and viscosity; such flour was obtained by extrusion and drying on rollers. The composite flours were obtained from cassava roots, sweet potato tubers, corn, rice and bean grains and cassava leaves. Four composite flours were formulated taking four- to six-year-old children’s daily nutrient requirements (protein, iron, zinc and beta-carotenes as a basis. The extruder was operated at 90ºC, 300 rpm screw rotation speed, 17.64 g/min feed flow, with 30% moisture mixture. The dryer rollers were operated at 4 rpm roller rotation speed, 90ºC surface temperature and 1 mm separation between rollers. It was determined that flour dried on rollers led to more complete cooking and modified starch granule structure than precooking by extrusion, thereby producing flour having greater solubility in water, less water absorption, higher consistency and smaller viscosity, comparable to that of pattern flour.

New radiometric ages on gneisses of the Oliverian domes in New Hampshire and Massachusetts

International Nuclear Information System (INIS)

Zartman, R.E.; Leo, G.W.

1985-01-01

Gneissic plutons of the Oliverian domes, mantled by Ammonoosuc Volcanics, are located along the axis of the Bronson Hill anticlinorium from New Hampshire to Connecticut. The contacts between the plutonic and volcanic rocks appear to be concordant on a regional scale, but gneiss intrudes the volcanics in several domes. Available radiometric and fossil evidence suggests that the Ammonoosuc Volcanics have a Middle Ordovician age but are somewhat older than the Oliverian gneisses. New U-Pb zircon data from Oliverian gneisses of six domes plot on a concordia diagram as an almost colinear array that yields an upper intercept age of about 444 m.y. The plotted data vary from nearly concordant to moderately discordant, the degree of discordance, correlating with 207 Pb/ 206 Pb ages that range from 459 to 415 m.y. The pattern of discordance does not relate to the uranium contents of the zircons nor to the geographic distribution of the domes. If 207 Pb/ 206 Pb ages are considered individually without an assumed consanguinity of the units, however, they do not find particular support in geologic relationships. Thus, they prefer the concordia intercept age of 444 +/- 8 m.y. for the suite as the best estimate for the time of crystallization of the Oliverian gneisses. Possibly, the Whitefield, Gneiss in the Jefferson dome represents a 10 to 15 m.y. older unit, although they are cautious about claiming such resolution with the present data

Visualisation and Immersion Dome Experience for Inspired Participation

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Anna P. Gawlikowska

2018-03-01

Full Text Available Public protests, which lead to increased administrative and permission procedures, are amongst the most important obstacles in development of wind energy projects. The community’s fears of visual and acoustic impacts of new power plants are commonly recognized as the weakest aspects of public acceptance. To address these issues Visualisation Dome has been designed to better communicate the economic, political, spatial, ecological and social benefits of wind power plants and the associated risks to local communities. The approach combines the experimental and simulation method. The integrated analysis software tool, which allows assessing the impacts of planed wind power plants underpins their 360-degree video and audio simulations. The Visualisation Dome demonstration resulted in 57% of the interviewed participants improving their opinion of wind power following the experience. Visualisation Dome’s novel approach for improving procedural justice of wind energy projects development forms innovative, interactive and streamlined processes, and enables constructive participation of audiences.

Structure-based membrane dome mechanism for Piezo mechanosensitivity.

Science.gov (United States)

Guo, Yusong R; MacKinnon, Roderick

2017-12-12

Mechanosensitive ion channels convert external mechanical stimuli into electrochemical signals for critical processes including touch sensation, balance, and cardiovascular regulation. The best understood mechanosensitive channel, MscL, opens a wide pore, which accounts for mechanosensitive gating due to in-plane area expansion. Eukaryotic Piezo channels have a narrow pore and therefore must capture mechanical forces to control gating in another way. We present a cryo-EM structure of mouse Piezo1 in a closed conformation at 3.7Å-resolution. The channel is a triskelion with arms consisting of repeated arrays of 4-TM structural units surrounding a pore. Its shape deforms the membrane locally into a dome. We present a hypothesis in which the membrane deformation changes upon channel opening. Quantitatively, membrane tension will alter gating energetics in proportion to the change in projected area under the dome. This mechanism can account for highly sensitive mechanical gating in the setting of a narrow, cation-selective pore. © 2017, Guo et al.

A Cascade of Wnt, Eda, and Shh Signaling Is Essential for Touch Dome Merkel Cell Development.

Science.gov (United States)

Xiao, Ying; Thoresen, Daniel T; Miao, Lingling; Williams, Jonathan S; Wang, Chaochen; Atit, Radhika P; Wong, Sunny Y; Brownell, Isaac

2016-07-01

The Sonic hedgehog (Shh) signaling pathway regulates developmental, homeostatic, and repair processes throughout the body. In the skin, touch domes develop in tandem with primary hair follicles and contain sensory Merkel cells. The developmental signaling requirements for touch dome specification are largely unknown. We found dermal Wnt signaling and subsequent epidermal Eda/Edar signaling promoted Merkel cell morphogenesis by inducing Shh expression in early follicles. Lineage-specific gene deletions revealed intraepithelial Shh signaling was necessary for Merkel cell specification. Additionally, a Shh signaling agonist was sufficient to rescue Merkel cell differentiation in Edar-deficient skin. Moreover, Merkel cells formed in Fgf20 mutant skin where primary hair formation was defective but Shh production was preserved. Although developmentally associated with hair follicles, fate mapping demonstrated Merkel cells primarily originated outside the hair follicle lineage. These findings suggest that touch dome development requires Wnt-dependent mesenchymal signals to establish reciprocal signaling within the developing ectoderm, including Eda signaling to primary hair placodes and ultimately Shh signaling from primary follicles to extrafollicular Merkel cell progenitors. Shh signaling often demonstrates pleiotropic effects within a structure over time. In postnatal skin, Shh is known to regulate the self-renewal, but not the differentiation, of touch dome stem cells. Our findings relate the varied effects of Shh in the touch dome to the ligand source, with locally produced Shh acting as a morphogen essential for lineage specification during development and neural Shh regulating postnatal touch dome stem cell maintenance.

A Cascade of Wnt, Eda, and Shh Signaling Is Essential for Touch Dome Merkel Cell Development.

Directory of Open Access Journals (Sweden)

Ying Xiao

2016-07-01

Full Text Available The Sonic hedgehog (Shh signaling pathway regulates developmental, homeostatic, and repair processes throughout the body. In the skin, touch domes develop in tandem with primary hair follicles and contain sensory Merkel cells. The developmental signaling requirements for touch dome specification are largely unknown. We found dermal Wnt signaling and subsequent epidermal Eda/Edar signaling promoted Merkel cell morphogenesis by inducing Shh expression in early follicles. Lineage-specific gene deletions revealed intraepithelial Shh signaling was necessary for Merkel cell specification. Additionally, a Shh signaling agonist was sufficient to rescue Merkel cell differentiation in Edar-deficient skin. Moreover, Merkel cells formed in Fgf20 mutant skin where primary hair formation was defective but Shh production was preserved. Although developmentally associated with hair follicles, fate mapping demonstrated Merkel cells primarily originated outside the hair follicle lineage. These findings suggest that touch dome development requires Wnt-dependent mesenchymal signals to establish reciprocal signaling within the developing ectoderm, including Eda signaling to primary hair placodes and ultimately Shh signaling from primary follicles to extrafollicular Merkel cell progenitors. Shh signaling often demonstrates pleiotropic effects within a structure over time. In postnatal skin, Shh is known to regulate the self-renewal, but not the differentiation, of touch dome stem cells. Our findings relate the varied effects of Shh in the touch dome to the ligand source, with locally produced Shh acting as a morphogen essential for lineage specification during development and neural Shh regulating postnatal touch dome stem cell maintenance.

[Choroidal thickness assessment with SD-OCT in high myopia with dome-shaped macula].

Science.gov (United States)

Chebil, A; Ben Achour, B; Chaker, N; Jedidi, L; Mghaieth, F; El Matri, L

2014-03-01

To measure macular choroidal thickness (CT) using spectral-domain optical coherence tomography (SD-OCT) in highly myopic eyes with dome-shaped macula (DSM), and to investigate whether the choroid is thicker in these eyes compared to highly myopic eyes without MB. A cross-sectional study of 200 eyes was performed between January 2010 and June 2012. Twenty-four highly myopic eyes (12%) had a dome-shaped macula. All patients underwent a complete ophthalmological examination, SD-OCT (TOPCON 2000), and B-scan ultrasonography. OCT scans were analyzed in 7 sections, and subfoveal CT was measured manually between the Bruch's membrane and the internal aspect of the sclera. The 20 eyes with isolated dome-shaped macular were paired by age and axial length (AL) with 20 eyes without macular involvement. In the subgroup with isolated MB, the mean subfoveal CT was 101.86 μm (± 21.35 μm). A statistically significant negative correlation was found between CT and AL (r=-0.623, P=0.0001). The regression equation demonstrated a decrease of 8.3 μm per mm of AL. In the subgroup without MB, matched with the subgroup with MB by age (P=0.591), and AL (P=0.815), the mean subfoveal CT was 89.54 μm (± 20.12 μm). The comparison between the two subgroups found a statistically significant difference in subfoveal CT (Pmacula compared to highly myopic eyes without dome-shaped macula. These findings suggest that abnormalities of the choroid may play a role in the pathogenesis of dome-shaped macula. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Ice crystal precipitation at Dome C site (East Antarctica)

Science.gov (United States)

Santachiara, G.; Belosi, F.; Prodi, F.

2016-01-01

For the first time, falling ice crystals were collected on glass slides covered with a thin layer of 2% formvar in chloroform at the Dome Concordia site (Dome C), Antarctica. Samplings were performed in the framework of the 27th Italian Antarctica expedition of the Italian National Program for Research in Antarctica in the period 21 February-6 August 2012. Events of clear-sky precipitations and precipitations from clouds were considered and the replicas obtained were examined under Scanning Electron Microscope (SEM). Several shapes of ice crystals were identified, including ;diamond dust; (plates, pyramids, hollow and solid columns), and crystal aggregates varying in complexity. Single events often contained both small (10 μm to 50 μm) and large (hundreds of microns) crystals, suggesting that crystals can form simultaneously near the ground (height of a few hundred metres) and at higher layers (height of thousands of metres). Images of sampled crystal replicas showed that single bullets are not produced separately, but by the disintegration of combinations of bullets. Rimed ice crystals were absent in the Dome C samples, i.e. the only mode of crystal growth was water vapour diffusion. On considering the aerosol in the sampled crystals, we reached the conclusion that inertial impaction, interception and Brownian motion were insufficient to explain the scavenged aerosol. We therefore presume that phoretic forces play a role in scavenging during the crystal growth process.

Geohydrology of the northern Louisiana salt-dome basin pertinent to the storage of radioactive wastes; a progress report

Science.gov (United States)

Hosman, R.L.

1978-01-01

Salt domes in northern Louisiana are being considered as possible storage sites for nuclear wastes. The domes are in an area that received regional sedimentation through early Tertiary (Eocene) time with lesser amounts of Quaternary deposits. The Cretaceous-Tertiary accumulation is a few thousand feet thick; the major sands are regional aquifers that extend far beyond the boundaries of the salt-dome basin. Because of multiple aquifers, structural deformation, and variations in the hydraulic characteristics of cap rock, the ground-water hydrology around a salt dome may be highly complex. The Sparta Sand is the most productive and heavily used regional aquifer. It is either penetrated by or overlies most of the domes. A fluid entering the Sparta flow system would move toward one of the pumping centers, all at or near municipalities that pump from the Sparta. Movement could be toward surface drainage where local geologic and hydrologic conditions permit leakage to the surface or to a surficial aquifer. (Woodard-USGS)

Beryllium-10 in the Taylor Dome ice core: Applications to Antarctic glaciology and paleoclimatology

Energy Technology Data Exchange (ETDEWEB)

Steig, E.J.

1996-12-31

An ice core was drilled at Taylor dome, East Antarctica, reaching to bedrock at 554 meters. Oxygen-isotope measurements reveal climatic fluctuations through the last interglacial period. To facilitate comparison of the Taylor Dome paleoclimate record with geologic data and results from other deep ice cores, several glaciological issues need to be addressed. In particular, accumulation data are necessary as input for numerical ice-flow-models, for determining the flux of chemical constituents from measured concentrations, and for calculation of the offset in age between ice and trapped air in the core. The analysis of cosmogenic beryllium-10 provides a geochemical method for constraining the accumulation-rate history at Taylor Dome. High-resolution measurements were made in shallow firn cores and snow pits to determine the relationship among beryllium-10 concentrations, wet and dry deposition mechanisms, and snow-accumulation rates. Comparison between theoretical and measured variations in deposition over the last 75 years constrains the relationship between beryllium-10 deposition and global average production rates. The results indicate that variations in geomagnetically-modulated production-rate do not strongly influence beryllium-10 deposition at Taylor Dome. Although solar modulation of production rate is important for time scales of years to centuries, snow-accumulation rate is the dominant control on ice-core beryllium-10 concentrations for longer periods. Results show that the Taylor Dome core can be used to provide new constraints on regional climate over the last 130,000 years, complementing the terrestrial and marine geological record from the Dry Valley, Transantarctic Mountains and western Ross Sea.

78 FR 58996 - Tapered Roller Bearings from the People's Republic of China: Notice of Court Decision Not in...

Science.gov (United States)

2013-09-25

... Sawblades Mfrs. Coalition v. United States, 626 F.3d 1374 (Fed. Cir. 2010) (``Diamond Sawblades''), the... a complaint with the CIT to challenge various aspects of the Final Results. \\2\\ Tapered Roller...

ASTEP: Towards the detection and characterization of exoplanets from Dome C

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Rauer H.

2011-02-01

Full Text Available The ASTEP project (Antarctic Search for Transiting ExoPlanets, aims at testing the quality of the Dome C site in Antarctica for photometry in the visible, as well as detecting and characterizing transiting exoplanets. A dedicated telescope, ASTEP400, has been developped and installed at Concordia. The first campaign took place during the winter 2010, and the telescope functionned nominally during all the winter. A first analysis of the data leads to a precision of 189 and 205 ppm for WASP-19 and WASP-18 respectively, for continuous observations during 1 month. This shows that extremely high precision photometry is achievable from Dome C.

78 FR 45912 - Tapered Roller Bearings and Parts Thereof, Finished and Unfinished, From the People's Republic of...

Science.gov (United States)

2013-07-30

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-601] Tapered Roller Bearings and..., International Trade Administration, U.S. Department of Commerce, 14th Street and Constitution Avenue NW... Duty New Shipper Review AGENCY: Import Administration, International Trade Administration, Department...

Annually-resolved temperature reconstructions of the past 2000 years from Dome-Fuji, East Antarctica

Science.gov (United States)

Motizuki, Yuko; Takahashi, Kazuya; Nakai, Yoichi; Motoyama, Hideaki

2016-04-01

We present annually-resolved temperature and SST reconstructions of the past 2000 years based on water (oxygen and deuterium) isotope measurement on a shallow ice core drilled in 2010 at Dome Fuji station, East Antarctica. These time series records will be an essential contribution to the PAGES 2k project from sparse data area in Antarctica. Dome Fuji station is located on a summit of Dronning Maud Land at an altitude of 3810 m a.s.l. (above sea level) (77o19'01'' S, 39o42'12'' E) in East Antarctica. The 10 m depth mean snow temperature at Dome Fuji is -57.3oC1). The inland area around Dome Fuji has been recognized to be especially unique: The snow and ice there contain much stratospheric information. The direct evidence for this comes from tritium contents originated from the nuclear bomb tests in the 1960s; the tritium fallout at the Dome Fuji site is outstandingly high among 16 snow pit samples widely collected over Antarctica2). To date the concerned Dome Fuji ice core, we applied volcanic signature matching to transfer the West Antarctic Ice Sheet (WAIS) Divide ice core chronology constructed by annual layer counting as used in the study by Sigl et al. (2014)3). In our presentation, we confine ourselves to discuss the oscillation periodicity that we observed in the oxygen isotope record in our data: The periods of approximately 10, 20, and 200 years were found. We will present the time series analyses for this in detail, and will discuss the origin of this periodicity. References: 1) Kameda, T., Motoyama, H., Fujita, S., and Takahashi, S.: "Past temporal and spatial variability of surface mass balance at Dome Fuji", East Antarctica, by the stake method from 1995 to 2006, J. Glaciol., 54, 107-116, 2008. 2) Fourre, E., Jean-Baptiste, P., Dapoigny, A., Baumier, D., Petit, J.-R., and Jouzel, J.: "Past and recent tritium levels in Arctic and Antarctic polar caps", Earth Planet. Sc. Lett., 245, 56-64, 2006. 3) Sigl, M., J. McConnell, M. Toohey, M. Curran, S. Das, R

The positioning of federate sports in Portugal: handball, basketball, roller hockey and volleyball

OpenAIRE

Gonçalves, Celina; Correia, Abel

2005-01-01

Sport is constituted by a multiplicity of activities with different purposes, concepts and cultural representations. Before the increase of supply, Sports Federations need to understand the practitioners in relation to the several possibilities of practice and to position their sports according to their competitors. In this context, the purpose of this study is the positioning of team federate sports (handball, basketball, roller hockey and volleyball). According to Lindon et al.,...

Distraction Osteogenesis Maxillary Expansion (DOME) for Adult Obstructive Sleep Apnea Patients with High Arched Palate.

Science.gov (United States)

Liu, Stanley Yung-Chuan; Guilleminault, Christian; Huon, Leh-Kiong; Yoon, Audrey

2017-08-01

A narrow maxilla with high arched palate characterizes a phenotype of obstructive sleep apnea (OSA) patients that is associated with increased nasal resistance and posterior tongue displacement. Current maxillary expansion techniques for adults are designed to correct dentofacial deformity. We describe distraction osteogenesis maxillary expansion (DOME) tailored to adult patients with OSA with narrow nasal floor and high arched palate without soft tissue redundancy. DOME is performed with placement of maxillary expanders secured by mini-implants along the midpalatal suture. This minimizes the maxillary osteotomies necessary to re-create sutural separation for reliable expansion at the nasal floor and palatal vault. We report the safety and efficacy profile of the first 20 patients at Stanford who underwent DOME.

78 FR 40692 - Tapered Roller Bearings and Parts Thereof, Finished and Unfinished, From the People's Republic of...

Science.gov (United States)

2013-07-08

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-601] Tapered Roller Bearings and..., International Trade Administration, Department of Commerce. SUMMARY: The Department of Commerce (Department) is... Department selected one mandatory respondent for individual examination (i.e., Changshan Peer Bearing Co. Ltd...

Forecasting cracked collectors on anticlinal type structures at late stage of exploration in oil and gas area

Science.gov (United States)

Hasanov, M. A.; Aleksandrov, B. L.; Eljayev, A. S.; Ezirbaev, T. B.; Gatsaeva, S. S.

2017-10-01

The possibility of using complex information on morphological parameters of structures, block porosity and the reservoir pressure gradient over previously explored deposits for the development of a multidimensional equation for estimating secondary porosity is considered. This is examined by the example of reservoirs with secondary (fractured) porosity of the Upper Cretaceous carbonate deposits of the Tersko-Sunzhenskaya oil and gas bearing region of the Ciscaucasia. The use of this equation makes it possible to predict the magnitude of the secondary porosity on the anticlinal structures, which are newly discovered by seismic methods at a later stage of exploration in the relevant oil and gas region, as a quantitative criterion that predicts the presence of a trap.

The Selection of Materials for Roller Chains From The Perspective Of Manufacturing Process

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Rahmat Saptono

2010-10-01

Full Text Available The selection of materials for an engineering component is not only requested by its design function and shape, but also the sequence through which it is manufactured. The manufacturing operation of roller chains involves drawing and trimming processes aimed at producing semi-finished chain drives component with a well-standardized dimension. In addition to final combination of properties required by design constraints, the ability of materials to be formed into a desired shape and geometry without failure is also critical. The objective of materials selection should therefore involve additional attributes that are not typically  accommodated by the standard procedure of materials selection. The present paper deals with the selection of materials for roller chains from the perspective of manufacturing process. Ears and un-uniform wall thickness have been identified as a key problem in the mass production of component. Provided all process parameters were established, the  anisotropy factor of materials is critical. Simulative test can be reasonably used to obtain material performance indices that can be added up to the standard procedure of material selection. Of three commercially available steel grades evaluated with regard to the criteria defined, one grade is more suitable for the present objective.

Compressive Sensing of Roller Bearing Faults via Harmonic Detection from Under-Sampled Vibration Signals.

Science.gov (United States)

Tang, Gang; Hou, Wei; Wang, Huaqing; Luo, Ganggang; Ma, Jianwei

2015-10-09

The Shannon sampling principle requires substantial amounts of data to ensure the accuracy of on-line monitoring of roller bearing fault signals. Challenges are often encountered as a result of the cumbersome data monitoring, thus a novel method focused on compressed vibration signals for detecting roller bearing faults is developed in this study. Considering that harmonics often represent the fault characteristic frequencies in vibration signals, a compressive sensing frame of characteristic harmonics is proposed to detect bearing faults. A compressed vibration signal is first acquired from a sensing matrix with information preserved through a well-designed sampling strategy. A reconstruction process of the under-sampled vibration signal is then pursued as attempts are conducted to detect the characteristic harmonics from sparse measurements through a compressive matching pursuit strategy. In the proposed method bearing fault features depend on the existence of characteristic harmonics, as typically detected directly from compressed data far before reconstruction completion. The process of sampling and detection may then be performed simultaneously without complete recovery of the under-sampled signals. The effectiveness of the proposed method is validated by simulations and experiments.

Petrography, mineralization and mineral explorations in the Zendan salt dome (Hara, Bandar Lengeh

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Habib Biabangard

2018-04-01

Full Text Available Introduction The Zendan salt dome is located at 80 Km north of Bandar-Lengeh and 110 Km west of Bandar-Khamir cities in the Hormozgan province. Based on the structural geology of Iran, the Zendan salt dome is placed in the southeastern part of the Zagros zone (Stocklin, 1968. Important units in this area are Hormuz, Mishan, Aghajari and Bakhtiari formations with the Precambrian age (Alian and Bazamad, 2014. The Hormuz formation with the four members of H1, H2, H3, and H4 is the oldest formation (Ahmadzadeh Heravi et al., 1991. Basalt and diabase rocks are mostly rocks that are exposed in the Zendan salt dome. Magnetite and hematite iron mineralization happened in all the building rocks of salt dome, and is not a uniform mineralization. Iron mineralization contains hematite, spicularite, magnetite, goethite, and iron hydroxides. Magnetite-hematite-oligist layers (red soil are the most iron mineralization in the Zendan salt dome, which are usually broken and scattered with gypsum layers (mostly anhydrite, respectively. Another form of iron mineralization is a mixture of hematite and magnetite (about 10 to 15% in diabase rocks. Copper mineralization consists of pyrite and chalcopyrite minerals that are mostly in tuff and shale units. The presence of low immobile trace elements in the Zendan salt dome and type of alteration shows that maybe the origin of this iron is deposited from brine fluid. Therefore, this deposit can be classified into VMS deposits. Materials and methods We have taken 60 samples rocks from the Zendan salt dome, and then prepared 20 thin and polished sections. Petrographic studies were done and 9 samples were selected for analysis. These samples were sent to the Zarzma laboratory and the amount of FeO was determined by the wet chemical method and other amounts of oxides were determined by XRF. Six samples were analyzed for determining the major elements with the XRF method in the Binalood laboratory. Nine samples from vines

The thermal environment of the fiber glass dome for the new solar telescope at Big Bear Solar Observatory

Science.gov (United States)

Verdoni, A. P.; Denker, C.; Varsik, J. R.; Shumko, S.; Nenow, J.; Coulter, R.

2007-09-01

The New Solar Telescope (NST) is a 1.6-meter off-axis Gregory-type telescope with an equatorial mount and an open optical support structure. To mitigate the temperature fluctuations along the exposed optical path, the effects of local/dome-related seeing have to be minimized. To accomplish this, NST will be housed in a 5/8-sphere fiberglass dome that is outfitted with 14 active vents evenly spaced around its perimeter. The 14 vents house louvers that open and close independently of one another to regulate and direct the passage of air through the dome. In January 2006, 16 thermal probes were installed throughout the dome and the temperature distribution was measured. The measurements confirmed the existence of a strong thermal gradient on the order of 5° Celsius inside the dome. In December 2006, a second set of temperature measurements were made using different louver configurations. In this study, we present the results of these measurements along with their integration into the thermal control system (ThCS) and the overall telescope control system (TCS).

Comparison of the diagenetic and reservoir quality evolution between the anticline crest and flank of an Upper Jurassic carbonate gas reservoir, Abu Dhabi, United Arab Emirates

Science.gov (United States)

Morad, Daniel; Nader, Fadi H.; Gasparrini, Marta; Morad, Sadoon; Rossi, Carlos; Marchionda, Elisabetta; Al Darmaki, Fatima; Martines, Marco; Hellevang, Helge

2018-05-01

This petrographic, stable isotopic and fluid inclusion microthermometric study of the Upper Jurassic limestones of an onshore field, Abu Dhabi, United Arab Emirates (UAE) compares diagenesis in flanks and crest of the anticline. The results revealed that the diagenetic and related reservoir quality evolution occurred during three phases, including: (i) eogenesis to mesogenesis 1, during which reservoir quality across the field was either deteriorated or preserved by calcite cementation presumably derived from marine or evolved marine pore waters. Improvement of reservoir quality was due to the formation of micropores by micritization of allochems and creation of moldic/intragranular pores by dissolution of peloids and skeletal fragments. (ii) Obduction of Oman ophiolites and formation of the anticline of the studied field was accompanied by cementation by saddle dolomite and blocky calcite. High homogenization temperatures (125-175 °C) and high salinity (19-26 wt% NaCl eq) of the fluid inclusions, negative δ18OVPDB values (-7.7 to -2.9‰), saddle shape of dolomite, and the presence of exotic cements (i.e. fluorite and sphalerite) suggest that these carbonates were formed by flux of hot basinal brines, probably related to this tectonic compression event. (iii) Mesogenesis 2 during subsidence subsequent to the obduction event, which resulted in extensive stylolitization and cementation by calcite. This calcite cement occluded most of the remaining moldic and inter-/intragranular pores of the flank limestones (water zone) whereas porosity was preserved in the crest. This study contributes to: (1) our understanding of differences in the impact of diagenesis on reservoir quality evolution in flanks and crests of anticlines, i.e. impact of hydrocarbon emplacement on diagenesis, and (2) relating various diagenetic processes to burial history and tectonic events of foreland basins in the Arabian Gulf area and elsewhere.

Possible evidence for contemporary doming of the Adirondack Mountains, New York, and suggested implications for regional tectonics and seismicity

Science.gov (United States)

Isachsen, Y.W.

1975-01-01

The Adirondack Mountain massif is a dissected elongate dome having a north-northeast axis about 190 km long, and an east-west dimension of about 140 km. The dome exposes a core of Proterozoic metamorphic rocks from which the Paleozoic cover rocks have been eroded, except in several north-northeast-trending graben. The minimum amplitude of the dome, based on a 'reconstruction' of the Proterozoic-Paleozoic unconformity is 1600 m. The Adirondack dome is an anomalous feature of the eastern edge of the North American craton. It differs from other uplifts in the Interior Lowlands of the craton not only in terms of the greater combined amplitude and area of its uplift, but in the present high elevation of its Mountains (up to 1600 m) which are unequalled on the craton except along the Rocky Mountain front and in the Torngat Mountains of northernmost Labrador. This prompted an interest in the possibility that the Adirondack dome has undergone neotectonic regeneration and may be undergoing domical uplift at the present time. Accordingly, leveling records were consulted at the National Geodetic Survey data base in Rockville, Maryland, and used to construct leveling profiles. The most informative of these extends north-south along the block-faulted eastern flank of the Adirondack dome, extending from Saratoga Springs to Rouses Point, a distance of 245 km. A comparison of the level lines for 1955 and 1973 demonstrates that arching has occurred. An uplift of 40 mm along the central portion of the line, and a corresponding subsidence of 50 mm at the northern end, has produced a net increase in the amplitude of arching of 90 mm in the 18-year interval. This differential uplift, particularly with subsidence at the northern end, argues for a tectonic rather than glacio-isostatic mechanism. Pending releveling across the center of the Adirondack dome, it is tempting to extrapolate the releveling profile and suggest that the Adirondacks as a whole may be undergoing contemporary doming

Transparent Yttria for IR Windows and Domes - Past and Present

National Research Council Canada - National Science Library

Hogan, Patrick; Stefanik, Todd; Willingham, Charles; Gentilman, Richard

2004-01-01

...) atmospheric transmission band at both ambient and elevated temperatures. Current state-of-the-art yttria's thermomechanical properties are adequate for a number of IR window and dome applications, but only marginal for the most demanding missions...

Electrical resistivity tomography applied to a complex lava dome: 2D and 3D models comparison

Science.gov (United States)

Portal, Angélie; Fargier, Yannick; Lénat, Jean-François; Labazuy, Philippe

2015-04-01

The study of volcanic domes growth (e.g. St. Helens, Unzen, Montserrat) shows that it is often characterized by a succession of extrusion phases, dome explosions and collapse events. Lava dome eruptive activity may last from days to decades. Therefore, their internal structure, at the end of the eruption, is complex and includes massive extrusions and lava lobes, talus and pyroclastic deposits as well as hydrothermal alteration. The electrical resistivity tomography (ERT) method, initially developed for environmental and engineering exploration, is now commonly used for volcano structure imaging. Because a large range of resistivity values is often observed in volcanic environments, the method is well suited to study the internal structure of volcanic edifices. We performed an ERT survey on an 11ka years old trachytic lava dome, the Puy de Dôme volcano (French Massif Central). The analysis of a recent high resolution DEM (LiDAR 0.5 m), as well as other geophysical data, strongly suggest that the Puy de Dôme is a composite dome. 11 ERT profiles have been carried out, both at the scale of the entire dome (base diameter of ~2 km and height of 400 m) on the one hand, and at a smaller scale on the summit part on the other hand. Each profile is composed of 64 electrodes. Three different electrode spacing have been used depending on the study area (35 m for the entire dome, 10 m and 5 m for its summit part). Some profiles were performed with half-length roll-along acquisitions, in order to keep a good trade-off between depth of investigation and resolution. Both Wenner-alpha and Wenner-Schlumberger protocols were used. 2-D models of the electrical resistivity distribution were computed using RES2DINV software. In order to constrain inversion models interpretation, the depth of investigation (DOI) method was applied to those results. It aims to compute a sensitivity index on inversion results, illustrating how the data influence the model and constraining models

Statistical analysis of the sustained lava dome emplacement and destruction processes at Popocatépetl volcano, Central México

Science.gov (United States)

Mendoza-Rosas, Ana Teresa; Gómez-Vázquez, Ángel; De la Cruz-Reyna, Servando

2017-06-01

Popocatépetl volcano reawakened in 1994 after nearly 70 years of quiescence. Between 1996 and 2015, a succession of at least 38 lava domes have been irregularly emplaced and destroyed, with each dome reaching particular volumes at specific emplacement rates. The complexity of this sequence is analyzed using statistical methods in an attempt to gain insight into the physics and dynamics of the lava dome emplacement and destruction process and to objectively assess the hazards related to that volcano. The time series of emplacements, dome residences, lava effusion lulls, and emplaced dome volumes and thicknesses are modeled using the simple exponential and Weibull distributions, the compound non-homogeneous generalized Pareto-Poisson process (NHPPP), and the mixture of exponentials distribution (MOED). The statistical analysis reveals that the sequence of dome emplacements is a non-stationary, self-regulating process most likely controlled by the balance between buoyancy-driven magma ascent and volatile exsolution crystallization. This balance has supported the sustained effusive activity for decades and may persist for an undetermined amount of time. However, the eruptive history of Popocatépetl includes major Plinian phases that may have resulted from a breach in that balance. Certain criteria to recognize such breaching conditions are inferred from this statistical analysis.

Lab-scale roller table mill for investigating the grinding behaviour of coal

Energy Technology Data Exchange (ETDEWEB)

Werner, V.; Zelkowski, J.; Schoenert, K. [Inst. for Energy Process Engineering and Fuel Technology and Inst. of Mineral Processing, Univ. Clausthal, Clausthal-Zellerfeld (Germany)

1999-11-01

The test mill is equipped with one roller. The material bed can be discharged completely after overroling. Grinding force, torque and gap width are measured. Cycle tests with three coals have been performed for simulating a closed circuit process. The grinding behaviour is characterized by the following relations: compaction of the particle bed and specific power draft vs. specific grinding force, production of fine material (dust), circuit factor, specific surface of the dust and specific work-input of the grinding circuit vs. specific power draft. (orig.)

Implications of thermophysical properties in geoscientific investigations for the disposal of nuclear waste in a salt dome

International Nuclear Information System (INIS)

Kopietz, J.

1984-01-01

Examples from laboratory and in-situ experiments on the thermomechanical behavior of rock salt are used to discuss the implications of thermophysical properties for disposal of nuclear waste in a salt dome. The implications of thermophysical properties are also illustrated by a brief review of geothermal investigations made within the scope of geological and hydrogeological exploration of the Gorleben salt dome in northern Germany. High-resolution temperature measurements performed in shallow and deep boreholes drilled for the exploration of the Gorleben salt dome, together with thermal conductivity measurements on representative core samples from these boreholes, are contributing to a determination of groundwater flow in the covering layers of the salt dome and to the identification of zones of impurity (eg carnallitite layers) within the salt structure. Data from these experiments are used for setting up numerical models for heat propagation around a prospective waste repository in the Gorleben salt dome. Long-term creep experiments on samples of rock salt at up to 400 deg C are used to derive constitutive relations on the creep behavior of salt. In-situ heating experiments are being conducted in the Asse salt mine to determine the effect of a heat source on the integrity of the surrounding salt rock. (author)

Parametric analysis of lava dome-collapse events and pyroclastic deposits at Shiveluch volcano, Kamchatka, using visible and infrared satellite data

Science.gov (United States)

Krippner, Janine B.; Belousov, Alexander B.; Belousova, Marina G.; Ramsey, Michael S.

2018-04-01

For the years 2001 to 2013 of the ongoing eruption of Shiveluch volcano, a combination of different satellite remote sensing data are used to investigate the dome-collapse events and the resulting pyroclastic deposits. Shiveluch volcano in Kamchatka, Russia, is one of the world's most active dome-building volcanoes, which has produced some of the largest known historical block-and-ash flows (BAFs). Globally, quantitative data for deposits resulting from such large and long-lived dome-forming eruptions, especially like those at Shiveluch, are scarce. We use Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) thermal infrared (TIR), shortwave infrared (SWIR), and visible-near infrared (VNIR) data to analyze the dome-collapse scars and BAF deposits that were formed during eruptions and collapse events in 2001, 2004, 2005, 2007, 2009, 2010, and two events in 2013. These events produced flows with runout distances of as far as 19 km from the dome, and with aerial extents of as much as 22.3 km2. Over the 12 years of this period of investigation, there is no trend in deposit area or runout distances of the flows through time. However, two potentially predictive features are apparent in our data set: 1) the largest dome-collapse events occurred when the dome exceeded a relative height (from dome base to top) of 500 m; 2) collapses were preceded by thermal anomalies in six of the cases in which ASTER data were available, although the areal extent of these precursory thermal areas did not generally match the size of the collapse events as indicated by scar area (volumes are available for three collapse events). Linking the deposit distribution to the area, location, and temperature profiles of the dome-collapse scars provides a basis for determining similar future hazards at Shiveluch and at other dome-forming volcanoes. Because of these factors, we suggest that volcanic hazard analysis and mitigation at volcanoes with similar BAF emplacement behavior may

Marine aggregates and transparent exopolymeric particles (TEPs) as substrates for the stramenopilan fungi, the thraustochytrids: Roller table experimental approach.

Digital Repository Service at National Institute of Oceanography (India)

Damare, V.S.; Raghukumar, S.

In order to understand the kind of organic substrates utilized by thraustochytrids in the coastal water column, their growth in the presence of Transparent Exopolymeric Substances (TEPS) and aggregates generated in roller table experiments...

Window and dome technologies and materials; Proceedings of the Meeting, Orlando, FL, Mar. 27-29, 1989

Science.gov (United States)

Klocek, Paul

1989-09-01

Papers on window and dome technologies and methodologies are presented, covering the processing and application of window and dome materials such as polycrystalline MgAl2O4 spinel, yttria and lanthana-doped yttria, transparent aluminum oxynitride, sapphire materials, fluoride glass, zinc sulfide, and germanium materials. Other topics include high modulus layers as protective coatings for window materials, ultrahard coatings for IR materials, IR applications of GeC thin filems, CVD diamond for IR applications, amorphic diamond films grown with a laser-ion source, dome cooling, microwave shielding effectiveness of electrically conductive coated optical windows, and the window evaluation program for an airborne FLIR system. In addition, papers are presented on modeling optical properties of window materials, lattice symmetries and thermal expansion, rain damage protection for IR materials, optical window materials for hypersonic flow, the IR emission due to aerodynamic heating of missile domes, a ZnS window for the IR instrumentation system, hypersonic aerooptical effects, optical and semiconductor properties of lead telluride coatings, boron phosphide for coating IR transparencies, and the measurement of high out-of-band filter rejection characteristics.

Blowing off steam: Tuffisite formation as a regulator for lava dome eruptions

Directory of Open Access Journals (Sweden)

Jackie Evan Kendrick

2016-04-01

Full Text Available Tuffisites are veins of variably sintered, pyroclastic particles that form in conduits and lava domes as a result of localized fragmentation events during gas-and-ash explosions. Those observed in-situ on the active 2012 lava dome of Volcán de Colima range from voids with intra-clasts showing little movement and interpreted to be failure-nuclei, to sub-parallel lenses of sintered granular aggregate interpreted as fragmentation horizons, through to infilled fractures with evidence of viscous remobilization. All tuffisites show evidence of sintering. Further examination of the complex fracture-and-channel patterns reveals viscous backfill by surrounding magma, suggesting that lava fragmentation was followed by stress relaxation and continued viscous deformation as the tuffisites formed. The natural tuffisites are more permeable than the host andesite, and have a wide range of porosity and permeability compared to a narrower window for the host rock, and gauging from their significant distribution across the dome, we posit that the tuffisite veins may act as important outgassing pathways. To investigate tuffisite formation we crushed and sieved andesite from the lava dome and sintered it at magmatic temperatures for different times. We then assessed the healing and sealing ability by measuring porosity and permeability, showing that sintering reduces both over time. During sintering the porosity-permeability reduction occurs due to the formation of viscous necks between adjacent grains, a process described by the neck-formation model of Frenkel (1945. This process leads the granular starting material to a porosity-permeability regime anticipated for effusive lavas, and which describes the natural host lava as well as the most impervious of natural tuffisites. This suggests that tuffisite formation at Volcán de Colima constructed a permeable network that enabled gas to bleed passively from the magma. We postulate that this progressively reduced

The Vredefort Dome World Heritage Site: Client satisfaction with ...

African Journals Online (AJOL)

Given the substantial growth of whitewater rafting in the Vredefort Dome World Heritage Site (VDWHS), it quickly grew into an unregulated adventure tourism commodity. With the area being a World Heritage Site, concerns have arisen about the impact it could have on the environment, service quality and public safety.

77 FR 2031 - Tapered Roller Bearings and Parts Thereof, Finished and Unfinished From the People's Republic of...

Science.gov (United States)

2012-01-13

... Parts Thereof, Finished and Unfinished From the People's Republic of China: Extension of the Time Limit..., International Trade Administration, U.S. Department of Commerce, 14th Street and Constitution Avenue NW..., finished and unfinished from the People's Republic of China. See Tapered Roller Bearings and Parts Thereof...

76 FR 76143 - Tapered Roller Bearings and Parts Thereof, Finished and Unfinished, From the People's Republic of...

Science.gov (United States)

2011-12-06

..., the United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service... manufacturing of tapered roller bearings and parts thereof in the United States, also notified the Department... manufacturing the domestic like product, and therefore, is an interested party pursuant to section 771(9)(D) of...

Dome-shaped High Tibial Osteotomy: A Long-term Follow-up Study

Directory of Open Access Journals (Sweden)

Hongsen Chiang

2006-01-01

Conclusion: Dome-shaped HTO is a durable time-buying procedure for patients with unicompartmental medial gonarthrosis, and can avoid subsequent development of patella baja that may complicate further prosthetic arthroplasty.

Post-cracking tensile behaviour of steel-fibre-reinforced roller-compacted-concrete for FE modelling and design purposes

International Nuclear Information System (INIS)

Jafarifar, N.; Pilakoutas, K.; Angelakopoulos, H.; Bennett, T.

2017-01-01

Fracture of steel-fibre-reinforced-concrete occurs mostly in the form of a smeared crack band undergoing progressive microcracking. For FE modelling and design purposes, this crack band could be characterised by a stress-strain (σ-ε) relationship. For industrially-produced steel fibres, existing methodologies such as RILEM TC 162-TDF (2003) propose empirical equations to predict a trilinear σ-ε relationship directly from bending test results. This paper evaluates the accuracy of these methodologies and their applicability for roller-compacted-concrete and concrete incorporating steel fibres recycled from post-consumer tyres. It is shown that the energy absorption capacity is generally overestimated by these methodologies, sometimes up to 60%, for both conventional and roller-compacted concrete. Tensile behaviour of fibre-reinforced-concrete is estimated in this paper by inverse analysis of bending test results, examining a variety of concrete mixes and steel fibres. A multilinear relationship is proposed which largely eliminates the overestimation problem and can lead to safer designs. [es

Automatic Identification of Subtechniques in Skating-Style Roller Skiing Using Inertial Sensors

Science.gov (United States)

Sakurai, Yoshihisa; Fujita, Zenya; Ishige, Yusuke

2016-01-01

This study aims to develop and validate an automated system for identifying skating-style cross-country subtechniques using inertial sensors. In the first experiment, the performance of a male cross-country skier was used to develop an automated identification system. In the second, eight male and seven female college cross-country skiers participated to validate the developed identification system. Each subject wore inertial sensors on both wrists and both roller skis, and a small video camera on a backpack. All subjects skied through a 3450 m roller ski course using a skating style at their maximum speed. The adopted subtechniques were identified by the automated method based on the data obtained from the sensors, as well as by visual observations from a video recording of the same ski run. The system correctly identified 6418 subtechniques from a total of 6768 cycles, which indicates an accuracy of 94.8%. The precisions of the automatic system for identifying the V1R, V1L, V2R, V2L, V2AR, and V2AL subtechniques were 87.6%, 87.0%, 97.5%, 97.8%, 92.1%, and 92.0%, respectively. Most incorrect identification cases occurred during a subtechnique identification that included a transition and turn event. Identification accuracy can be improved by separately identifying transition and turn events. This system could be used to evaluate each skier’s subtechniques in course conditions. PMID:27049388

Automatic Identification of Subtechniques in Skating-Style Roller Skiing Using Inertial Sensors

Directory of Open Access Journals (Sweden)

Yoshihisa Sakurai

2016-04-01

Full Text Available This study aims to develop and validate an automated system for identifying skating-style cross-country subtechniques using inertial sensors. In the first experiment, the performance of a male cross-country skier was used to develop an automated identification system. In the second, eight male and seven female college cross-country skiers participated to validate the developed identification system. Each subject wore inertial sensors on both wrists and both roller skis, and a small video camera on a backpack. All subjects skied through a 3450 m roller ski course using a skating style at their maximum speed. The adopted subtechniques were identified by the automated method based on the data obtained from the sensors, as well as by visual observations from a video recording of the same ski run. The system correctly identified 6418 subtechniques from a total of 6768 cycles, which indicates an accuracy of 94.8%. The precisions of the automatic system for identifying the V1R, V1L, V2R, V2L, V2AR, and V2AL subtechniques were 87.6%, 87.0%, 97.5%, 97.8%, 92.1%, and 92.0%, respectively. Most incorrect identification cases occurred during a subtechnique identification that included a transition and turn event. Identification accuracy can be improved by separately identifying transition and turn events. This system could be used to evaluate each skier’s subtechniques in course conditions.

Re-assessment of recent (2008–2013 surface mass balance over Dome Argus, Antarctica

Directory of Open Access Journals (Sweden)

Minghu Ding

2016-04-01

Full Text Available At Dome Argus, East Antarctica, the surface mass balance (SMB from 2008 to 2013 was evaluated using 49 stakes installed across a 30×30 km area. Spatial analysis showed that at least 12 and 20 stakes are needed to obtain reliable estimates of SMB at local scales (a few hundred square metres and regional scales (tens of square kilometres, respectively. The estimated annual mean SMB was 22.9±5.9 kg m−2 yr−1, including a net loss by sublimation of −2.22±0.02 kg m−2 yr−1 and a mass gain by deposition of 1.37±0.01 kg m−2 yr−1. Therefore, ca. 14.3% of precipitation was modified after deposition, which should be considered when interpreting snow or ice core records produced by future drilling projects. The surface snow density and SMB in the western portion of Dome Argus are higher than in other areas, and these differences are likely related to the katabatic wind, which is strengthened by topography in this sector. A new digital elevation model (DEM of Dome Argus was generated, confirming that both peaks of the dome can be considered as the summit of the East Antarctic Ice Sheet. Findings from this study should be valuable for validating SMB estimates obtained from regional climate models and DEMs established using remote-sensing data.

MacDonald Dam reconstruction : using roller-compacted concrete

Energy Technology Data Exchange (ETDEWEB)

O' Neil, E. [AMEC Earth and Environmental Ltd., Sydney, NS (Canada)

2007-04-01

Located in Nova Scotia, the MacDonald Dam was commissioned in 1928. The dam consists of a 122 metre-long, 16 metre-high concrete structure comprised of an intake structure, stoplog openings, and a 34 metre-long free-overflow spillway. A 488 metre-long power canal was added as an upgrade in the 1950s. This paper provided details of the roller-compact concrete (RCC) used in the dam's recent rehabilitation following a dam failure analysis in 2003 by Nova Scotia Power Inc. RCC was chosen to help keep the dam's construction project on schedule. The layout and cross-section of the spillway was selected with consideration given to the RCC placing operation. A lift thickness of 0.20 m was selected. A formed ogee crest consisting of conventional reinforced concrete was constructed on top of the RCC. The downstream steps of the spillway were also covered with cast-in-place concrete. A low level sluice was designed to resist the weight of the wet RCC. The design compressive strength of the RCC was 20 MPa. The forms used to support the cast-in-place facing concrete on the upstream face of the dam were constructed full height and were braced back to the downstream face of the existing concrete structure prior to the start of RCC placement. Formwork inserts were placed in the facing concrete as construction progressed. Crack inducers were pre-placed on the forms. Aggregates from a local source were transported to a pug mill as the RCC construction progressed. The RCC was spread into 0.20 m lifts using a small bull-dozer, and the facing concrete was vibrated into the lift below. RCC lifts were compacted using a 9 tonne vibratory drum roller. The RCC placing operation was completed over a period of 10 days. Following the completion of the RCC portion of the dam, the remainder of the cast-in-place concrete was completed. It was concluded that the RCC provided a durable, low-maintenance structure that was completed at a lower price and in a shorter time-frame than

Two- and three-dimensional topographic analysis of pathologically myopic eyes with dome-shaped macula and inferior staphyloma by spectral domain optical coherence tomography.

Science.gov (United States)

García-Ben, Antonio; Kamal-Salah, Radua; García-Basterra, Ignacio; Gonzalez Gómez, Ana; Morillo Sanchez, María José; García-Campos, Jose Manuel

2017-05-01

To investigate the posterior anatomical structure of pathologically myopic eyes with dome-shaped macula and inferior staphyloma using spectral domain optical coherence tomography (SD-OCT). Our database of 260 pathologically myopic eyes was analyzed retrospectively to identify patients with dome-shaped macula and inferior staphyloma. All patients underwent vertical and horizontal SD-OCT scans across the central fovea, with three-dimensional macular map reconstruction. Best-corrected visual acuity, axial length, and choroidal thickness measurements were recorded. The macular bulge height was also analyzed in eyes with dome-shaped macula. In the three-dimensional images, the symmetry and orientation of the main plane of the inward incurvation of the macula were examined. Twenty-eight (10.7%) of the 260 pathologically myopic eyes had dome-shaped macula of one of three different types: a round radially symmetrical dome (eight eyes, 28.5%), a horizontal axially symmetrical oval-shaped dome (15 eyes, 53.5%), or a vertical axially symmetrical oval-shaped dome (five eyes, 17.8%). The macular bulge height was significantly greater in horizontal oval-shaped dome eyes (p = 0.01, for each comparison). Inferior posterior staphylomas were observed in ten (3.8%) of the 260 pathologically myopic eyes with asymmetrical macular bends. Vertical and horizontal OCT sectional scanning in combination with three-dimensional macular map reconstruction provides important information for understanding the posterior anatomical structure of dome-shaped macula and inferior staphyloma in pathologically myopic eyes.

The utility of petroleum seismic exploration data in delineating structural features within salt anticlines

Science.gov (United States)

Stockton, S.L.; Balch, Alfred H.

1978-01-01

The Salt Valley anticline, in the Paradox Basin of southeastern Utah, is under investigation for use as a location for storage of solid nuclear waste. Delineation of thin, nonsalt interbeds within the upper reaches of the salt body is extremely important because the nature and character of any such fluid- or gas-saturated horizons would be critical to the mode of emplacement of wastes into the structure. Analysis of 50 km of conventional seismic-reflection data, in the vicinity of the anticline, indicates that mapping of thin beds at shallow depths may well be possible using a specially designed adaptation of state-of-the-art seismic oil-exploration procedures. Computer ray-trace modeling of thin beds in salt reveals that the frequency and spatial resolution required to map the details of interbeds at shallow depths (less than 750 m) may be on the order of 500 Hz, with surface-spread lengths of less than 350 m. Consideration should be given to the burial of sources and receivers in order to attenuate surface noise and to record the desired high frequencies. Correlation of the seismic-reflection data with available well data and surface geology reveals the complex, structurally initiated diapir, whose upward flow was maintained by rapid contemporaneous deposition of continental clastic sediments on its flanks. Severe collapse faulting near the crests of these structures has distorted the seismic response. Evidence exists, however, that intrasalt thin beds of anhydrite, dolomite, and black shale are mappable on seismic record sections either as short, discontinuous reflected events or as amplitude anomalies that result from focusing of the reflected seismic energy by the thin beds; computer modeling of the folded interbeds confirms both of these as possible causes of seismic response from within the salt diapir. Prediction of the seismic signatures of the interbeds can be made from computer-model studies. Petroleum seismic-reflection data are unsatisfactory for

Application of Dang Van criterion to rolling contact fatigue in wind turbine roller bearings under elastohydrodynamic lubrication conditions

DEFF Research Database (Denmark)

Cerullo, Michele

2014-01-01

classic Hertzian and elastohydrodynamic lubrication theories have been used to model the pressure distribution acting on the inner raceway and results are compared according to the Dang Van multiaxial fatigue criterion. The contact on the bearing raceway is simulated by substituting the roller...

Functional Balance Training Using a Domed Device

Science.gov (United States)

2005-02-01

people. Exerc. Sport Sci. Rev. 31:182–187. 2003. 17. Roubenoff, R. Sarcopenia and its im- plications for the elderly . Eur. J. Clin. Nutr. 54(Suppl 3):S40–7... elderly and the injured (7, 10, 18). Functional balance training involves skilled body movement patterns that si- multaneously require movement and...important aspect of athletic and occupational perfor- mance, in the elderly , and for injury rehabilitation, where use of a novel domed device can be

Upheaval Dome, Utah, USA: Impact Origin Confirmed

OpenAIRE

Buchner, Elmar; Kenkmann, Thomas

2008-01-01

Upheaval Dome is a unique circular structure on the Colorado Plateau in SE Utah, the origin of which has been controversially discussed for decades. It has been interpreted as a crypto volcanic feature, a salt diapir, a pinched-off salt diapir, and an eroded impact crater. While recent structural mapping, modeling, and analyses of deformation mechanisms strongly support an impact origin, ultimate proof, namely the documentation of unambiguous shock features, has yet to be successfully provide...

Computational Analysis of Natural Ventilation Flows in Geodesic Dome Building in Hot Climates

Directory of Open Access Journals (Sweden)

Zohreh Soleimani

2016-08-01

Full Text Available For centuries, dome roofs were used in traditional houses in hot regions such as the Middle East and Mediterranean basin due to its thermal advantages, structural benefits and availability of construction materials. This article presents the computational modelling of the wind- and buoyancy-induced ventilation in a geodesic dome building in a hot climate. The airflow and temperature distributions and ventilation flow rates were predicted using Computational Fluid Dynamics (CFD. The three-dimensional Reynolds-Averaged Navier-Stokes (RANS equations were solved using the CFD tool ANSYS FLUENT15. The standard k-epsilon was used as turbulence model. The modelling was verified using grid sensitivity and flux balance analysis. In order to validate the modelling method used in the current study, additional simulation of a similar domed-roof building was conducted for comparison. For wind-induced ventilation, the dome building was modelled with upper roof vents. For buoyancy-induced ventilation, the geometry was modelled with roof vents and also with two windows open in the lower level. The results showed that using the upper roof openings as a natural ventilation strategy during winter periods is advantageous and could reduce the indoor temperature and also introduce fresh air. The results also revealed that natural ventilation using roof vents cannot satisfy thermal requirements during hot summer periods and complementary cooling solutions should be considered. The analysis showed that buoyancy-induced ventilation model can still generate air movement inside the building during periods with no or very low wind.

Microstructure and soft magnetic properties of Finemet-type ribbons obtained by twin-roller melt-spinning

International Nuclear Information System (INIS)

Pozo Lopez, G.; Fabietti, L.M.; Condo, A.M.; Urreta, S.E.

2010-01-01

Soft magnetic ribbons of Finemet-type (Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 ) alloys are synthesized by the twin-roller melt-spinning technique directly from the melt, at tangential wheel speeds of 15, 18, 19 and 20 m/s. The microstructure and the magnetic properties are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), differential thermal analysis (DTA), thermo-gravimetric analysis (TGA) and hysteresis loops measurements. Samples cooled at 20 m/s are amorphous, while those quenched at lower wheel speeds are partially crystalline. All samples studied present saturation magnetization values (150-160 A m 2 /kg) higher than the commercial Finemet alloys (∼135 A m 2 /kg), obtained by controlled crystallization of amorphous single-roller melt-spun alloys. Optimal soft magnetic properties - σ S =(154±8) A m 2 /kg and H C =(6.9±0.9) A/m - are found in samples quenched at 19 m/s, consisting of size-distributed bcc Fe-Si nanograins (∼18 nm in average) embedded in an amorphous residual matrix. A minority nanocrystalline magnetic phase (≤10 nm) is also detected.

Performance of integrated systems of automated roller shade systems and daylight responsive dimming systems

Energy Technology Data Exchange (ETDEWEB)

Park, Byoung-Chul; Choi, An-Seop; Jeong, Jae-Weon [Department of Architectural Engineering, Sejong University, Kunja-Dong, Kwangjin-Gu, Seoul (Korea, Republic of); Lee, Eleanor S. [Building Technologies Department, Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

2011-03-15

Daylight responsive dimming systems have been used in few buildings to date because they require improvements to improve reliability. The key underlying factor contributing to poor performance is the variability of the ratio of the photosensor signal to daylight workplane illuminance in accordance with sun position, sky condition, and fenestration condition. Therefore, this paper describes the integrated systems between automated roller shade systems and daylight responsive dimming systems with an improved closed-loop proportional control algorithm, and the relative performance of the integrated systems and single systems. The concept of the improved closed-loop proportional control algorithm for the integrated systems is to predict the varying correlation of photosensor signal to daylight workplane illuminance according to roller shade height and sky conditions for improvement of the system accuracy. In this study, the performance of the integrated systems with two improved closed-loop proportional control algorithms was compared with that of the current (modified) closed-loop proportional control algorithm. In the results, the average maintenance percentage and the average discrepancies of the target illuminance, as well as the average time under 90% of target illuminance for the integrated systems significantly improved in comparison with the current closed-loop proportional control algorithm for daylight responsive dimming systems as a single system. (author)

Morphometric and rheological study of lunar domes of Marius Hills ...

Indian Academy of Sciences (India)

70

(2013) had given emphasis to the study of the morphology of cones having diameters between 1 to2 km using .... for the dome-35 is marked with a white polygon as shown in Fig.5a. Orthoimage, ..... Geochemical and mineralogical analysis of ...

The Fulldome Curriculum for the Spitz SciDome Digital Planetarium: Volume 2

Science.gov (United States)

Bradstreet, David H.; Sanders, S. J.; Huggins, S.

2014-01-01

The Spitz Fulldome Curriculum (FDC) for the SciDome digital planetarium ushered in a new and innovative way to present astronomical pedagogy via its use of the unique teaching attributes of the digital planetarium. In the case of the FDC, which uses the ubiquitous Starry Night planetarium software as its driving engine, these engaging and novel teaching techniques have also been made usable to desktop computers and flat-screen video projectors for classroom use. Volume 2 of the FDC introduces exciting new classes and mini-lessons to further enlighten and invigorate students as they struggle with often difficult three dimensional astronomical concepts. Additionally, other topics with related astronomical ties have been created to integrate history into planetarium presentations. One of the strongest advantages of the SciDome is its use of Starry Night as its astronomical engine. With it students can create their own astronomical configurations in the computer lab or at home, using the PC or Mac version. They can then simply load their creations onto the SciDome planetarium system and display them for their classmates on the dome. This poster will discuss and illustrate some of the new content that has been developed for Volume 2. Topics covered in Volume 2 include eclipses, plotting planet locations on a curtate orbit chart by observing their positions in the sky, time and timekeeping (including sidereal day, hour angles, sidereal time, LAST, LMST, time zones and the International Date Line), teaching to the Boy Scout Merit Badge requirements, plotting scale analemmas on the surface of planets and interpreting them, precession, astronomical events in revolutionary Boston, the Lincoln Almanac Trial, eclipsing binaries, lunar librations, a trip through the universe, watching the speed of light move in real time, stellar sizes and the Milky Way.

Determination of uranium and thorium in rock samples from Harargaj Anticline by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Rahman, M.; Molla, N.I.; Sharif, A.K.M.; Basunia, S.; Islam, S.; Miah, R.U.; Hossain, S.M.; Chowdhury, M.I.; Bhuiyan, A.D.; Stegnar, P.

1993-01-01

Uranium and thorium were determined in geological materials such as radioactive rock samples collected from the Harargaj Anticline in Moulavi Bazar. The pure instrumental neutron activation analysis (INAA) technique was used in qualitative and quantitative analysis of the rock samples for U and Th. The samples were properly prepared together with their standards and simultaneously irradiated in a neutron flux of the order of 10 12 n*cm -2 *s -1 using the TRIGA MARK II research reactor facility at the AERE, Savar, Dhaka. After activation the samples were subjected to γ-ray spectrometry using a high purity germanium detection system. As a result of the analysis, U and Th could be determined. The data are consistent with the values reported by the ground radiometric survey group for some of the samples. (author) 7 refs.; 1 fig.; 2 tabs

Serous retinal detachment accompanied by MEWDS in a myopic patient with dome-shaped macula.

Science.gov (United States)

Shin, Min Kyu; Byon, Ik Soo; Park, Sung Who; Lee, Ji Eun

2014-01-01

Macular serous retinal detachment (MSRD) is a rare complication in highly myopic patients with an inferior staphyloma, tilted disc, or dome-shaped macula. Multiple evanescent white dot syndrome (MEWDS) presents with sudden visual loss and multiple yellowish dots that resolve spontaneously within several weeks. The authors report the development and spontaneous resolution of subretinal fluid accompanied by MEWDS in a myopic patient with a dome-shaped macula. Dysfunction of the retinal pigment epithelium due to MEWDS likely induced temporary MSRD in this patient. Copyright 2014, SLACK Incorporated.

Occupational exposure to unburnt tobacco and potential risk of toxic optic neuropathy: A cross-sectional study among beedi rollers in selected rural areas of coastal Karnataka, India.

Directory of Open Access Journals (Sweden)

Soujanya Kaup

Full Text Available Beedi also known as poor man's cigarette is manufactured in almost all major states of India. Beedi workers are exposed to various health risks. There is an increased risk of systemic absorption of tobacco through skin and mucous membrane. The optic nerve is susceptible to damage from several toxic substances including tobacco. This group of disorders is known as toxic optic neuropathy (TON. The association of TON with occupational exposure to unburnt tobacco in beedi rollers has not been explored.Among the beedi rollers in Mangaluru and Bantwal talukas of Dakshina Kannada District, Karnataka, India: to assess the magnitude of potential TON utilizing colour vision and contrast sensitivity as screening tools and to identify the demographic, biological and occupational factors associated with potential TON.A community-based cross-sectional study was conducted from April-Sept 2016 in Mangaluru and Bantwal talukas, of Dakshina Kannada district, Karnataka. Beedi rollers from twelve villages (six from each taluka were included. In each of the selected villages, the investigators identified beedi collection centres and all the eligible beedi rollers were included in the study till the required number of beedi rollers for that village was achieved. Participants were screened at the study site for visual acuity, colour vision and contrast sensitivity and those with abnormal colour and contrast sensitivity in the presence of good visual acuity were considered to have potential TON.A total of 377 beedi rollers were approached; of which 365 consented to take part in the study (response rate: 96.81%. Women constituted the majority of the participants (n = 338, 92.6%. Based on the screening criteria, the prevalence of potential TON was 17.5% (n = 64, 95% CI: 13.5-21.9. On multiple logistic regression analysis, duration of beedi rolling (Adj OR: 1.061; 95% CI 1.015-1.109, p = 0.009, advancing age (Adj OR: 1.096; 95% CI 1.058-1.136, p<0.001 and presence of

Light, shadows and surface characteristics: the multispectral Portable Light Dome

Science.gov (United States)

Watteeuw, Lieve; Hameeuw, Hendrik; Vandermeulen, Bruno; Van der Perre, Athena; Boschloos, Vanessa; Delvaux, Luc; Proesmans, Marc; Van Bos, Marina; Van Gool, Luc

2016-11-01

A multispectral, multidirectional, portable and dome-shaped acquisition system is developed within the framework of the research projects RICH (KU Leuven) and EES (RMAH, Brussels) in collaboration with the ESAT-VISICS research group (KU Leuven). The multispectral Portable Light Dome (MS PLD) consists of a hemispherical structure, an overhead camera and LEDs emitting in five parts of the electromagnetic spectrum regularly covering the dome's inside surface. With the associated software solution, virtual relighting and enhancements can be applied in a real-time, interactive manner. The system extracts genuine 3D and shading information based on a photometric stereo algorithm. This innovative approach allows for instantaneous alternations between the computations in the infrared, red, green, blue and ultraviolet spectra. The MS PLD system has been tested for research ranging from medieval manuscript illuminations to ancient Egyptian artefacts. Preliminary results have shown that it documents and measures the 3D surface structure of objects, re-visualises underdrawings, faded pigments and inscriptions, and examines the MS results in combination with the actual relief characteristics of the physical object. Newly developed features are reflection maps and histograms, analytic visualisations of the reflection properties of all separate LEDs or selected areas. In its capacity as imaging technology, the system acts as a tool for the analysis of surface materials (e.g. identification of blue pigments, gold and metallic surfaces). Besides offering support in answering questions of attribution and monitoring changes and decay of materials, the PLD also contributes to the identification of materials, all essential factors when making decisions in the conservation protocol.

Monitoring lava-dome growth during the 2004-2008 Mount St. Helens, Washington, eruption using oblique terrestrial photography

Science.gov (United States)

Major, J.J.; Dzurisin, D.; Schilling, S.P.; Poland, Michael P.

2009-01-01

We present an analysis of lava dome growth during the 2004–2008 eruption of Mount St. Helens using oblique terrestrial images from a network of remotely placed cameras. This underutilized monitoring tool augmented more traditional monitoring techniques, and was used to provide a robust assessment of the nature, pace, and state of the eruption and to quantify the kinematics of dome growth. Eruption monitoring using terrestrial photography began with a single camera deployed at the mouth of the volcano's crater during the first year of activity. Analysis of those images indicates that the average lineal extrusion rate decayed approximately logarithmically from about 8 m/d to about 2 m/d (± 2 m/d) from November 2004 through December 2005, and suggests that the extrusion rate fluctuated on time scales of days to weeks. From May 2006 through September 2007, imagery from multiple cameras deployed around the volcano allowed determination of 3-dimensional motion across the dome complex. Analysis of the multi-camera imagery shows spatially differential, but remarkably steady to gradually slowing, motion, from about 1–2 m/d from May through October 2006, to about 0.2–1.0 m/d from May through September 2007. In contrast to the fluctuations in lineal extrusion rate documented during the first year of eruption, dome motion from May 2006 through September 2007 was monotonic (± 0.10 m/d) to gradually slowing on time scales of weeks to months. The ability to measure spatial and temporal rates of motion of the effusing lava dome from oblique terrestrial photographs provided a significant, and sometimes the sole, means of identifying and quantifying dome growth during the eruption, and it demonstrates the utility of using frequent, long-term terrestrial photography to monitor and study volcanic eruptions.

Digital Imaging for Siple Dome Ice Core Analysis, Antarctica, Version 1

Data.gov (United States)

National Aeronautics and Space Administration — This data set contains high-resolution digital images of thin and thick sections cut from the 1003 meter Siple Dome A main ice core. The images are useful for...

Potential for creation of a salt dome following disposal of radioactive waste in a salt layer

International Nuclear Information System (INIS)

Fries, G.

1987-01-01

The study aims at quantifying the possibility of creation of a salt dome from a salt layer in which heat-emitting radioactive waste would be buried. Volume 1 describes the results of numerical computer simulations, and of laboratory-scale models in centrifuges. Volume 2 envisages, in a geological perspective, the origin of salt domes, the mechanisms of thei formation, and the associated parameters [fr

Potential for creation of a salt dome following disposal of radioactive waste in a salt layer

International Nuclear Information System (INIS)

Charo, L.; Habib, P.

1987-01-01

The study aims at quantifying the possibility of creation of a salt dome from a salt layer in which heat-emitting radioactive waste would be buried. Volume 1 describes the results of numerical computer simulations, and of laboratory-scale models in centrifuges. Volume 2 envisages, in a geological perspective, the origin of salt domes, the mechanisms of their formation, and the associated parameters [fr

Structure and origin of Australian ring and dome features with reference to the search for asteroid impact events

Science.gov (United States)

Glikson, Andrew

2018-01-01

Ring, dome and crater features on the Australian continent and shelf include (A) 38 structures of confirmed or probable asteroid and meteorite impact origin and (B) numerous buried and exposed ring, dome and crater features of undefined origin. A large number of the latter include structural and geophysical elements consistent with impact structures, pending test by field investigations and/or drilling. This paper documents and briefly describes 43 ring and dome features with the aim of appraising their similarities and differences from those of impact structures. Discrimination between impact structures and igneous plugs, volcanic caldera and salt domes require field work and/or drilling. Where crater-like morphological patterns intersect pre-existing linear structural features and contain central morphological highs and unique thrust and fault patterns an impact connection needs to tested in the field. Hints of potential buried impact structures may be furnished by single or multi-ring TMI patterns, circular TMI quiet zones, corresponding gravity patterns, low velocity and non-reflective seismic zones.

Salt geologic evaluation of the impact of cryogenic fissures and halokinetic deformation processes on the integrity of the geological barrier of the salt dome Gorleben

International Nuclear Information System (INIS)

Hammer, Joerg; Fleig, Stephanie; Mingerzahn, Gerhard

2012-07-01

In several salt domes of the area close to Hannover fissures were observed that might be caused by thermally induced fissure formation due to cold periods (cryogenic fissures). Comprehensive substantial-structural analyses are performed as an example for the salt dome Bokeloh with respect to genesis and transferability to the salt dome Gorleben. Based on recent structure-geological, mineralogical-geochemical and micro-paleontological studies and thermo-mechanical modeling a solely thermally induced fissure formation due to cold periods is unlikely for the salt dome Bokeloh. There is a direct relation between the genesis of the salt dome Bokeloh, its regional tectonic site and the fissure formation. Due to the completely different genesis and another regional-tectonic situation the existence of cryogenic fissures is excluded for the salt dome Gorleben. The salt-geologic and experimental studies on the deformation of anhydrite layers in salt domes are summarized and evaluated with respect to the long-term consequences for a potential final repository for high-level heat-generating radioactive waste in the salt dome Gorleben. The studies confirm the older BGR studies that anhydrite layers do not represent hydraulic potential ling-distance liquid paths.

Alred Roller – An Innovator and a Traditionalist

Directory of Open Access Journals (Sweden)

Zavarský Ján

2017-12-01

Full Text Available This study focuses on the scenographer Alfred Roller (1864–1935 and his productions of Wagner’s musical dramas, with emphasis on Tristan and Isolde and Parsifal. It places Roller’s aesthetics in a historical, aesthetic, and artistic context, points to his inspiration by the Swiss scenography reformer Adolphe Appia, and cooperation with the music composer and conductor Gustav Mahler in the Vienna Court Opera. The text analyses the specifics of Roller’s scenography, which diverged from illusive stage and used light work as an important production principle. It concludes with a summary of the effect of Roller’s aesthetics on Ľudovít Hradský, the first leader of the production team at the Slovak National Theatre (1923–1928. The visual aspects of the Slovak National Theatre’s productions in that period were strongly inspired by expressionism and Art Nouveau, which were typical of German theatre at that time.

Abrasion Resistance and Mechanical Properties of Waste-Glass-Fiber-Reinforced Roller-compacted Concrete

Science.gov (United States)

Yildizel, S. A.; Timur, O.; Ozturk, A. U.

2018-05-01

The potential use of waste glass fibers in roller-compacted concrete (RCC) was investigated with the aim to improve its performance and reduce environmental effects. The research was focused on the abrasion resistance and compressive and flexural strengths of the reinforced concrete relative to those of reference mixes without fibers. The freeze-thaw resistance of RCC mixes was also examined. It was found that the use of waste glass fibers at a rate of 2 % increased the abrasion resistance of the RCC mixes considerably.

Development of in-structure design spectra for dome mounted equipment on underground waste storage tanks at the Hanford Site

International Nuclear Information System (INIS)

Julyk, L.J.

1995-09-01

In-structure response spectra for dome mounted equipment on underground waste storage tanks at the Hanford Site are developed on the basis of recent soil-structure-interaction analyses. Recommended design spectra are provided for various locations on the tank dome

Strain distribution and model for formation of eastern Umtanum Ridge anticline, south-central Washington

Energy Technology Data Exchange (ETDEWEB)

Price, E.H.

1979-10-01

Umtanum Ridge in south-central Washington is the topographic expression of a complex anticline within the Yakima Fold system in the Miocene Columbia River Basalt Group. The Yakima Fold system, which is partly contained within the Hanford Site, is an example of a layered basalt sequence folded near the surface of the earth. The Pasco Basin stratigraphic nomenclature is used in this repot. Rockwelll Hanford Operations, under contract to the US Department of Energy, is investigating the feasibility of therminal high-level nuclear waste storage in mined repositories in basalt beneath the Hanford Site. Because thereis essentially no basalt within the Site that has not been involved in some folding, any potential location for a repository will be either on the limbs or near the hinge zone of a Yakima Fold structure. Umtanum Ridge is the best exposed Yakima Fold structure in the vicinity of the Site for studying the nature and three-dimensional style of deformation of a multilayered basalt sequence. The structural geometry, distribution of strain within the Umtanum structure and deformational mechanisms of the Umtanum Ridge are discussed.

Strain distribution and model for formation of eastern Umtanum Ridge anticline, south-central Washington

International Nuclear Information System (INIS)

Price, E.H.

1979-10-01

Umtanum Ridge in south-central Washington is the topographic expression of a complex anticline within the Yakima Fold system in the Miocene Columbia River Basalt Group. The Yakima Fold system, which is partly contained within the Hanford Site, is an example of a layered basalt sequence folded near the surface of the earth. The Pasco Basin stratigraphic nomenclature is used in this repot. Rockwelll Hanford Operations, under contract to the US Department of Energy, is investigating the feasibility of therminal high-level nuclear waste storage in mined repositories in basalt beneath the Hanford Site. Because thereis essentially no basalt within the Site that has not been involved in some folding, any potential location for a repository will be either on the limbs or near the hinge zone of a Yakima Fold structure. Umtanum Ridge is the best exposed Yakima Fold structure in the vicinity of the Site for studying the nature and three-dimensional style of deformation of a multilayered basalt sequence. The structural geometry, distribution of strain within the Umtanum structure and deformational mechanisms of the Umtanum Ridge are discussed

Structural evolution and tectonic style of the Tunisian central Atlas; role of inherited faults in compressive tectonics (Ghoualguia anticline)

Science.gov (United States)

Briki, Haithem; Ahmadi, Riadh; Smida, Rabiaa; Rekhiss, Farhat

2018-04-01

Geological mapping, field cross sections, structural analyses and new subsurface data were used to characterize the geometry and tectonic setting of the Ghoualguia structure, which is an E-W-trending anticline located between the Kalaa Khasba and Rouhia troughs of the central Tunisian Atlas. The results show an important NE-SW extensional phase during the Mesozoic, as demonstrated by synsedimentary normal faults (NW-SE and E-W) and thickness variations. In the Aouled Mdoua area, the absence of Paleocene-Eocene rocks indicates that the eastern and western parts of the Ghoualguia structure were separated by high topography. In addition, the angular unconformity observed between the Upper Cretaceous unit (Abiod Fm.) and the upper Eocene series (Souar Fm.) provide evidence of a tilted-block structure delineated by North-South faults. A major compressional phase during the middle to late Miocene created various detachment levels that originated mainly in the Triassic and Cretaceous deposits. Faults were reactivated as thrust and strike-slip faults, creating fault-related fold structures. In the core of the Ghoualguia fold, an original S-dipping normal fault underwent reverse movement as a back thrust. Fault-slip data indicate that the area records a major NE-SW extensional phase that took place during the late Miocene and Pliocene. A balanced cross section provides insight into the existence of two main detachment levels rooted in the Triassic (depth ± 6 km) and the lower Cretaceous (depth ± 2.5 km). The balanced cross section highlights a shortening of about 2.5 km along cross section and 1.5 km in the central part of the Ghoualguia anticline. This work underlines the predominant role of the inherited Mesozoic structures during the evolution of the Atlassic range and their influence on the geometry of the central Tunisian atlas.

Friction-Stir-Welded and Spin-Formed End Domes for Cryogenic Tanks

Science.gov (United States)

Hales, S. J.; Tayon, W. A.; Domack, M. S.

2012-01-01

Manufacturing of single-piece end domes for cryogenic tanks employing spin forming of tailored, friction-stir-welded blanks of Al-Li alloy 2195 plate offers cost and reliability benefits. The introduction of plastic deformation into a friction stir weld is a unique feature of the proposed manufacturing route. This investigation addressed abnormal grain growth [AGG] within the friction stir weldments during postfabrication processing of a prototype dome. The phenomenon of AGG was observed during the solution heat treatment [SHT] phase of T8 tempering and is a major concern for meeting specifications. Such abrupt microstructural transitions can be detrimental to notch-sensitive mechanical properties, such as ductility and/or fracture toughness. If the issue of AGG cannot be resolved, then the acceptance of this approach as a viable manufacturing route may be in jeopardy. The innovative approach adopted in this investigation was the insertion of a stand-alone, Intermediate Annealing Treatment [IAT] between the spin forming and T8 processing operations. A simple, recovery annealing step was deemed to be the most readily-scalable solution when fabricating thin-walled, ellipsoidal domes. The research effort culminated in the development of an effective IAT, which resulted in a significant decrease in AGG following SHT. The processing philosophy adopted in designing the IAT is outlined and the microstructural reasons for success are discussed. The analytical results presented are consistent with promoting continuous grain growth during the IAT, thereby suppressing AGG during the SHT.

High-throughput creation of micropatterned PDMS surfaces using microscale dual roller casting

International Nuclear Information System (INIS)

DiBartolomeo, Franklin J; Ge, Ning; Trinkle, Christine A

2012-01-01

This work introduces microscale dual roller casting (MDRC), a novel high-throughput fabrication method for creating continuous micropatterned surfaces using thermosetting polymers. MDRC utilizes a pair of rotating, heated cylindrical molds with microscale surface patterns to cure a continuous microstructured film. Using unmodified polydimethylsiloxane as the thermosetting polymer, we were able to create optically transparent, biocompatible surfaces with submicron patterning fidelity. Compared to other roll-to-roll fabrication processes, this method offers increased flexibility in the types of materials and topography that can be generated, including dual-sided patterning, embedded materials and tunable film thickness. (paper)

Influence of ambient moisture on the compaction behavior of microcrystalline cellulose powder undergoing uni-axial compression and roller-compaction: a comparative study using near-infrared spectroscopy.

Science.gov (United States)

Gupta, Abhay; Peck, Garnet E; Miller, Ronald W; Morris, Kenneth R

2005-10-01

This study evaluates the effect of variation in the ambient moisture on the compaction behavior of microcrystalline cellulose (MCC) powder. The study was conducted by comparing the physico-mechanical properties of, and the near infrared (NIR) spectra collected on, compacts prepared by roller compaction with those collected on simulated ribbons, that is, compacts prepared under uni-axial compression. Relative density, moisture content, tensile strength (TS), and Young modulus were used as key sample attributes for comparison. Samples prepared at constant roller compactor settings and feed mass showed constant density and a decrease in TS with increasing moisture content. Compacts prepared under uni-axial compression at constant pressure and compact mass showed the opposite effect, that is, density increased while TS remained almost constant with increasing moisture content. This suggests difference in the influence of moisture on the material under roller compaction, in which the roll gap (i.e., thickness and therefore density) remains almost constant, vs. under uni-axial compression, in which the thickness is free to change in response to the applied pressure. Key sample attributes were also related to the NIR spectra using multivariate data analysis by the partial least squares projection to latent structures (PLS). Good agreement was observed between the measured and the NIR-PLS predicted values for all key attributes for both, the roller compacted samples as well as the simulated ribbons. Copyright (c) 2005 Wiley-Liss, Inc. and the American Pharmacists Association

Geologic appraisal of Paradox basin salt deposits for water emplacement

Science.gov (United States)

Hite, Robert J.; Lohman, Stanley William

1973-01-01

process and that any waste-storage or disposal sites in these structures should remain dry for hundreds of thousands of years.Trace to commercial quantities of oil and gas are found in all of the black shale-dolomite-anhydrite interbeds of the Paradox Member. These hydrocarbons constitute a definite hazard in the construction and operation of underground waste-storage or disposal facilities. However, many individual halite beds are of. sufficient thickness that a protective seal of halite can be left between the openings and the gassy beds.A total of 12 different localities were considered to be potential waste-storage or disposal sites in the Paradox basin. Two Sharer dome and Salt Valley anticline, were considered to have the most favorable characteristics.

Cerro Amarillo rhyolites, advanced AFC in the northern SVZ, Chile

International Nuclear Information System (INIS)

Godoy, E; Hildreth, W

2001-01-01

Cerro Amarillo is a Quaternary medium size (500m high, 2 km 2 ) rhyolite dome complex located close to the Chile-Argentina border, reaching a height of 4162 m, between the headwaters of the Rio Colina and the Nieves Negras Pass. It overlies a broad anticline of thick Middle Jurassic pelites (Alvarez et al., 1997). Thiele (1980) includes this complex in his 'Unidad Volcanica Antigua', a Pleistocene composite map unit made up of andesites and trachyandesites. Ramos et al. (1997), while recognizing its rhyolitic character, assigned a Tertiary age to the lava domes, most likely based on the late Pliocene age of silicic dikes outcropping eastward, in Argentina. Both the lack of younger overlying units and freshness of its components, together with preservation of the unconsolidated, easily eroded pyroclastic deposits at its base, suggest, however, that it is not older than Pleistocene (au)

Manufacturing of 5.5 Meter Diameter Cryogenic Fuel Tank Domes for the NASA Ares I Rocket

Science.gov (United States)

Jones, Ronald E.; Carter, Robert W.

2012-01-01

The Ares I rocket is the first launch vehicle scheduled for manufacture under the National Aeronautic and Space Administration s (NASA s) Constellation program. A series of full-scale Ares I development articles have been constructed on the Robotic Weld Tool at the NASA George C. Marshall Space Flight Center in Huntsville, Alabama. The Robotic Weld Tool is a 100 ton, 7-axis, robotic manufacturing system capable of machining and friction stir welding large-scale space hardware. This presentation will focus on the friction stir welding of 5.5m diameter cryogenic fuel tank components; specifically, the liquid hydrogen forward dome (LH2 MDA) and the common bulkhead manufacturing development articles (CBMDA). The LH2 MDA was the first full-scale, flight-like Ares I hardware produced under the Constellation Program. It is a 5.5m diameter elliptical dome assembly consisting of eight gore panels, a y-ring stiffener and a manhole fitting. All components are made from aluminum-lithium alloy 2195. Conventional and self-reacting friction stir welding was used on this article. Manufacturing solutions will be discussed including the implementation of photogrammetry, an advanced metrology technique, as well as fixtureless welding. The LH2 MDA is the first known fully friction stir welded dome ever produced. The completion of four Common Bulkhead Manufacturing Development Articles (CBMDA) will also be highlighted. Each CBMDA consists of a 5.5m diameter spun-formed dome friction stir welded to a y-ring stiffener. The domes and y-rings are made of aluminum 2014 and 2219 respectively. An overview of CBMDA manufacturing processes and the effect of tooling on weld defect formation will be discussed.

Disposal of high-level waste from nuclear power plants in Denmark. Salt dome investigations. v.2

International Nuclear Information System (INIS)

1981-01-01

The present report deals with the geological investigations performed for determing the feasibility of a repository for high-level waste in a salt dome. It is volume 2 of five volumes that together constitute the final report of the Danish utilities' salt dome investigations. The purpose of the work was to procure a more detailed knowledge of the geology of salt domes in North Jutland on example of Mors. The Mors dome is oval with the two axes of approx. 12.5 km and 8 km respectively. Two deep wells have been drilled into the salt. These wells reach 3400-3500 m below surface. Until a depth of about 3200 m Erslev 2 passes through rock salt of Zechstein 1 which is the oldest evaporite series. However, it could also be interlayed with the slightly younger Zechstein 2. At about 3200 m a marker layer was met with Zechstein 2 salt below. Interpretation of cores and results of downhole electromagnetic and borehole gravimetric measurements show that there is a large area around Erslev 2 which consists of very pure sodium chloride with traces of anhydrite (calcium, sulphate) 1-3%. This area is used for the repository design and safety evaluation. The hydrological conditions existing in the strata above the salt dome (caprock) have been investigated with the help of four hydrogeological wells, placed two each, on two different sites. The cores themselves were taken at various depths in all four holes. With these laboratory methods it has been possible to measure data relevant to hydrology - such as porosity and permeability - as well as geochemistry. (BP)

Building a roll-off roof or dome observatory a complete guide for design and construction

CERN Document Server

Hicks, John Stephen

2016-01-01

Almost every practical astronomer eventually aspires to have a fixed, permanent observatory for his or her telescope. A roll-off roof or dome observatory is the answer for the most popular home observatory design.  Almost every practical astronomer eventually aspires to have a fixed, permanent observatory for his or her telescope. A roll-off roof or dome observatory is the answer for the most popular home observatory design. Building a Roll-Off or Dome Observatory will help you decide whether to embark on the venture and will certainly increase your enthusiasm for the project. The author, both an amateur astronomer and a professional landscape architect, answers many of the common questions asked about observatory construction, covering the following topics: • Zoning, and by-law requirements common to most states, towns and municipalities • Where to locate the observatory • How to tailor the observatory for your particular needs • Tools and structural components required • Possible variations in de...

Justification of the Shape of a Non-Circular Cross-Section for Drilling With a Roller Cutter

Science.gov (United States)

Buyalich, Gennady; Husnutdinov, Mikhail

2017-11-01

The parameters of the shape of non-circular cross-section affect not only the process of blasting, but also the design of the tool and the process of drilling as well. In the conditions of open-pit mining, it is reasonable to use a roller cutter to produce a non-circular cross-section of blasting holes. With regard to the roller cutter, the impact of the cross-section shape on the oscillations of the axial force arising upon its rotation is determined. It is determined that a polygonal shape with rounded comers of the borehole walls connections and their convex shape, which ensures a smaller range of the total axial force and the torque deflecting the bit from the axis of its rotation is the rational form of the non-circular cross-section of the borehole in terms of bit design. It has been shown that the ratio of the number of cutters to the number of borehole corners must be taken into account when justifying the shape of the cross-section, both from the point of view of the effectiveness of the explosion action and from the point of view of the rational design of the bit.

Simulated Service and Stress Corrosion Cracking Testing for Friction Stir Welded Spun Formed Domes

Science.gov (United States)

Stewart, Thomas J.; Torres, Pablo D.; Caratus, Andrei A.; Curreri, Peter A.

2010-01-01

Simulated service testing (SST) development was required to help qualify a new 2195 aluminum lithium (Al-Li) alloy spin forming dome fabrication process for the National Aeronautics and Space Administration (NASA) Exploration Development Technology Program. The application for the technology is to produce high strength low weight tank components for NASA s next generation launch vehicles. Since plate material is not currently manufactured large enough to fabricate these domes, two plates are joined by means of friction stir welding. The plates are then pre-contour machined to near final thicknesses allowing for a thicker weld land and anticipating the level of stretch induced by the spin forming process. The welded plates are then placed in a spin forming tool and hot stretched using a trace method producing incremental contours. Finally the dome receives a room temperature contour stretch to final dimensions, heat treatment, quenching, and artificial aging to emulate a T-8 condition of temper. Stress corrosion cracking (SCC) tests were also performed by alternate immersion in a sodium chloride (NaCl) solution using the typical double beam assembly and with 4-point loaded specimens and use of bent-beam stress-corrosion test specimens under alternate immersion conditions. In addition, experiments were conducted to determine the threshold stress intensity factor for SCC (K(sub ISCC)) which to our knowledge has not been determined previously for Al-Li 2195 alloy. The successful simulated service and stress corrosion testing helped to provide confidence to continue to Ares 1 scale dome fabrication

Thermoluminescence age determination of Mt. Fuji lava dome, Takahara volcano, North Kanto, Central Japan

International Nuclear Information System (INIS)

Takashima, Isao

1999-01-01

Mt. Fuji lava dome thought to be formed by recent action of Takahara volcano, is reported to be due to eruption at the Holocene epoch age on 1,000 or 6,500 years ago. However, on either of them the lava dome did not directly conduct its age measurement, and its age is obtained indirectly from eruption age of tephra estimated to be same age. Recently, precision thermo-luminescence (TL) method is improved and upgraded, by using which formulation of the Mayu-yama in the Unzen volcano was cleared to be about 4,000 years ago which corresponded to be very young. In this paper, by using the TL method for lava dome racks, it was attempted to remove uncertainty forming an indirect age estimation shown as previously. As a result, adopted samples showed 6.5 to 7.4 ka in age value, which showed a good agreement under considering of error. This result was older than 1,000 and some years, and was younger than 20,000 to 25,000 years, which showed a good agreement with 6,500 years ago, obtained by combining closed layer order survey and 14-C age. It is thought to be an important contribution in future forecasting of volcano eruption that the last period action of the Takahara volcano must be at the Holocene epoch age. And, as limited to a quartz containing sample, this can be said to show priority of TL method for a method to directly obtain age of younger dome rock than 10,000 years. (G.K.)

Grand Sarcoui volcano (Chaîne des Puys, Massif Central, France), a case study for monogenetic trachytic lava domes

Science.gov (United States)

Miallier, D.; Pilleyre, T.; Boivin, P.; Labazuy, P.; Gailler, L.-S.; Rico, J.

2017-10-01

The Grand Sarcoui is a prominent trachytic volcano of the intraplate Quaternary volcanic field of Chaîne des Puys (Massif Central, France), which fulfills basic requirements for being qualified as monogenetic. Grand Sarcoui looks like a simple axisymmetric lava dome, but close observation reveals a complex and dissymmetric structure and composition. The construction of the dome, about 12.5 ka ago, combined both endogenous and exogenous growth which resulted in variable modes of emplacement and textures of the lava. One of its most interesting features is a large ( 0.29 106 m2) fan of deposits bearing hummocks and secondary hydro-eruption craters. Cross sections of these deposits demonstrate that they originated from a sector collapse accompanied by a blast-like event. The dome is covered by a thin layer of lapilli and ash, attributed to a delayed summit eruption which occurred about 10.6 ka ago, surprisingly late after its construction. So, this volcano has, at a reduced scale, features that are more usually observed in large composite volcanoes. However, some of these features differ slightly from those that have been documented to date, and they remain partly unexplained. This shows that monogenetic, well preserved, trachytic lava domes, are uncommon and poorly known, unlike rhyolitic, andesitic and dacitic domes.

Granitoid magmatism of Alarmaut granite-metamorphic dome, West Chukotka, NE Russia

Science.gov (United States)

Luchitskaya, M. V.; Sokolov, S. D.; Bondarenko, G. E.; Katkov, S. M.

2009-04-01

Main tectonic elements of West Chukotka are Alazey-Oloy, South-Anyui and Anyui-Chukotka fold systems, formed as a result of collision between structures of North-Asian continent active margin and Chukotka microcontinent [1-3]. South-Anyui fold system, separating Alazey-Oloy and Anyui-Chukotka systems, is considered as suture zon, formed as a result of oceanic basin closing [4-6]. Continent-microcontinent collision resulted in formation of large orogen with of northern and southern vergent structures, complicated by strike-slip deformations [7, 8]. Within Anyui-Chukotka fold system several rises, where most ancient deposits (crystalline basement and Paleozoic cover of Chukotka microcontinent) are exposed, were distinguished [2, 9-11]. Later they were considered as granite-metamorphic domes [12-14]. Alarmaut dome is located at West Chukotka to the north from Bilibino city and is traced from south to north in more than 120 km. General direction of structure is discordant to prevailing NW extensions of tectonic elements of the region. Paleozoic-Triassic deposits are exposed within the Alarmaut dome: 1) D3-C1 - crystalline schists, quartz-feldspar metasandstones, quartzites, marbles (700 m) [11]; 2) C1 - marblized limestones, quartz-feldspar metasandstones, quartzites, amphibole-pyroxene crystalline schists. Limestones contain corals, indicating Visean age of deposits [11]. Metamorphism reaches amphibolite facies, maximum P-T conditions are 660°С and 5 kbar. Migmatites, indicating in situ partial melting, are observed. Intensity of deformations of Paleozoic rocks increases at the boundary with Triassic deposits [11]; in the western part of dome slices of Pz rocks are separated by blastomylonite horizons [14]. Within Alramaut dome granitoids of Lupveem batholith (central part of dome), Bystrinsky pluton (southeastern part), and small Koyvel' and Kelil'vun plutons were studied. New U-Pb SHRIMP zircon data indicate Early Cretaceous (117-112 m.a.) age of granitoids [15

Fusée ceramic vaults and domes in the Netherlands

NARCIS (Netherlands)

Kamerling, M.W.

2011-01-01

This paper gives an overview of the fusée Ceramique vaults and domes constructed in The Netherlands just after World War II and describes the technique of construction as well as the advantages and disadvantages. Using only a minimum of concrete and steel, the environmental load of the vaults is

Paradox Basin site characterization report: preparation papers, Gibson Dome location

International Nuclear Information System (INIS)

1982-11-01

This document contains Part C, Identification of Pertinent Issues, of the site characterization report. The site characterization report, preparation papers, includes a description of detailed field studies and efforts to collect data to resolve key geologic and environmental issues in the Gibson Dome location within the Paradox Basin Region of Utah

VIRTUAL MODEL OF A ROLLER CONVEYOR INTEGRATED INTO A LOGISTIC FLOW

Directory of Open Access Journals (Sweden)

POPESCU Adrian

2015-11-01

Full Text Available In this article is presented, with the help of graphics, a logistic flow for palletizing and wrapping operations. The loaded pallets are transported by means of a roller conveyor. Creating the virtual model for the conveyer allows us to emphasize the compatibility elements between on the one hand the mechanical assemblies of the flow components and on the other hand the subassemblies of the conveyer structure. The paper has focused on the presentation of the conveyor specific assembly and how are placed the sensors on the mechanical structure of the conveyor. Finally, the main working phases are graphically presented within the flow, highlighting the loaded pallet positions in the flow.

Use of flyash in roller compacted concrete for Ghatghar pumped storage scheme in Maharashtra

Energy Technology Data Exchange (ETDEWEB)

Damani, R.L.; Kshirsagar, S.L.; Narkhede, C.L. [MERI, Nashik (India)

2003-07-01

The paper described the use of 'Roller Compacted Concrete' (RCE) in which about 60% of the cement will be replaced by fly ash for construction of two storage dams - Upper dam and Lower dam in the Thane district of India. These are part of the Ghatghar Pumped Storage Scheme to generate hydropower. Fly ash from Eklahare and Dahav thermal power plant and processed fly ash, Pozzocrete 63 and 83b grade, all proved suitable for the RCC mix. 1 tab.

Dome shaped micro-laser encapsulated in a flexible film

Science.gov (United States)

Ioppolo, T.; Manzo, M.

2014-11-01

In this paper, we demonstrated multimode laser emission from a dome shaped micro-scale resonator encapsulated in a flexible polymer film. The resonator with a radius of ~60 microns was made of Norland Blocking Adhesive (NBA 107) doped with a solution of rhodamine 6G and ethanol. The dome was encapsulated in a flexible polymeric film made of polydymethylsiloxane (PDMS) with a thickness of 1 mm. The micro-scale laser was optically pumped using a frequency doubled Q-switch Nd:YAG laser with pulse repetition of 10 Hz and pulse duration of 9 ns. Experiments were carried out to investigate the lasing properties of this laser structure. The pumping threshold for multimode laser emission was below 100 µJ cm-2. The average optical quality factor for all observed laser modes was of the order of 104. Using a fluence of 315.8 µJ cm-2 it was observed that the intensity of the laser emission dropped by 62% after 5 min of operation. These results showed that these solid state flexible lasers are easy to fabricate and can be integrated into novel flexible photonic devices and novel photonic sensors.

Barnes Ice Cap South Dome Trilateration Net Survey Data 1970-1984

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Barnes Ice Cap data set contains survey measurements of a network of 43 stakes along a 10 km flow line on the northeast flank of the south dome of the Barnes Ice...

Morphological and structural changes at the Merapi lava dome monitored in 2012-15 using unmanned aerial vehicles (UAVs)

Science.gov (United States)

Darmawan, Herlan; Walter, Thomas R.; Brotopuspito, Kirbani Sri; Subandriyo; I Gusti Made Agung Nandaka

2018-01-01

Dome-building volcanoes undergo rapid and profound topographic changes that are important to quantify for the purposes of hazard assessment. However, as hazardous lava domes often develop on high-altitude volcanoes that exhibit steep-sided topography, it is challenging to obtain direct field access and thus to analyze these morphological and structural changes. Merapi Volcano in Indonesia is a type example of such a volcano, as soon after its 2010 eruption, a new lava dome developed. This dome was partially destroyed during six distinct steam-driven explosions that occurred between 2012 and 2014. Here, we investigate the topographic and structural changes associated with these six steam-driven explosions by comparing close-range photogrammetric data obtained before and after these explosions. To accomplish this, we performed two UAV campaigns in 2012 and 2015. By applying the Structure from Motion (SfM) technique, we are able to construct three-dimensional point clouds, assess their quality by comparing them to a terrestrial laser scanning (TLS) dataset, and generate high-resolution Digital Elevation Models (DEMs) and photomosaics. The comparison of these two DEMs and photomosaics reveals changes in topography and the appearance of fractures. In the 2012 dataset, we find a dense fracture network striking to the NNW-SSE. In the post-eruptive 2015 dataset, we see that this NNW-SSE fracture trend is much more strongly expressed; we also detect the formation of aligned and elongated explosion craters, which are associated with the removal of over 200,000 m3 of dome material, most of which ( 70%) was deposited outside the crater region. Therefore, this study suggests that the locations of the steam-driven explosions at Merapi Volcano were controlled by the reactivation of preexisting structures. Moreover, some of the newly developed and reactivated fractures delineate a block on the southern slope of the dome, which could become structurally unstable and potentially

The Chaitén rhyolite lava dome: Eruption sequence, lava dome volumes, rapid effusion rates and source of the rhyolite magma

Science.gov (United States)

Pallister, John S.; Diefenbach, Angela K.; Burton, William C.; Munoz, Jorge; Griswold, Julia P.; Lara, Luis E.; Lowenstern, Jacob B.; Valenzuela, Carolina E.

2013-01-01

We use geologic field mapping and sampling, photogrammetric analysis of oblique aerial photographs, and digital elevation models to document the 2008-2009 eruptive sequence at Chaitén Volcano and to estimate volumes and effusion rates for the lava dome. We also present geochemical and petrologic data that contribute to understanding the source of the rhyolite and its unusually rapid effusion rates. The eruption consisted of five major phases: 1. An explosive phase (1-11 May 2008); 2. A transitional phase (11-31 May 2008) in which low-altitude tephra columns and simultaneous lava extrusion took place; 3. An exogenous lava flow phase (June-September 2008); 4. A spine extrusion and endogenous growth phase (October 2008-February 2009); and 5. A mainly endogenous growth phase that began after the collapse of a prominent Peléean spine on 19 February 2009 and continued until the end of the eruption (late 2009 or possibly earliest 2010). The 2008-2009 rhyolite lava dome has a total volume of approximately 0.8 km3. The effusion rate averaged 66 m3s-1 during the first two weeks and averaged 45 m3s-1 for the first four months of the eruption, during which 0.5 km3 of rhyolite lava was erupted. These are among the highest rates measured world-wide for historical eruptions of silicic lava. Chaitén’s 2008-2009 lava is phenocryst-poor obsidian and microcrystalline rhyolite with 75.3±0.3% SiO2. The lava was erupted at relatively high temperature and is remarkably similar in composition and petrography to Chaitén’s pre-historic rhyolite. The rhyolite’s normative composition plots close to that of low pressure (100-200 MPa) minimum melts in the granite system, consistent with estimates of approximately 5 to 10 km source depths based on phase equilibria and geodetic studies. Calcic plagioclase, magnesian orthopyroxene and aluminous amphibole among the sparse phenocrysts suggest derivation of the rhyolite by melt extraction from a more mafic magmatic mush. High temperature

Chaotic Dynamics of Cage Behavior in a High-Speed Cylindrical Roller Bearing

Directory of Open Access Journals (Sweden)

Long Chen

2016-01-01

Full Text Available This paper presents a mathematical model to investigate the nonlinear dynamic behavior of cage in high-speed cylindrical bearing. Variations of cage behavior due to varying cage eccentricity and cage guidance gap are observed. Hydrodynamic behavior in cage contacts is taken into consideration for a more realistic calculation of acting forces owing to high working speed. Analysis of real-time cage dynamic behavior on radial plane is carried out using chaos theory based on the theoretical and mathematical model established in the paper. The analytical results of this paper provide a solid foundation for designing and manufacturing of high-speed cylindrical roller bearing.

The Dome C site testing from an atmospheric physicist view

Science.gov (United States)

Argentini, S.; Pietroni, I.

Atmospheric field experiments were made at the French-Italian station of Concordia at Dome C during several years. These experiments were limited to the summer season. In 2005 Concordia has become a permanent base, this allowed to carry out STABLEDC (STudy of the Atmospheric Boundary Layer Environmental at Dome C plateau station) that is an atmospheric field experiment of the duration of one year. The aim of STABLEDC was to study the processes occurring in the long-lived stable and the weak convective atmospheric boundary layers, observed during winter and summer, respectively, and to collect the relevant parameters for the atmospheric models. Both in situ and ground based remote sensing instruments have been used to monitor the meteorological parameters. The first part of the paper gives a brief illustration of the objectives of the field experiment, and a description of site and instrumentation. The second part shows the behaviour of some micrometeorological parameters: temperature, wind speed, sensible heat flux. The surface radiation balance components are also shown. Finally some experimental activities are proposed.

Nonlinear vibration of a hemispherical dome under external water pressure

International Nuclear Information System (INIS)

Ross, C T F; McLennan, A; Little, A P F

2011-01-01

The aim of this study was to analyse the behaviour of a hemi-spherical dome when vibrated under external water pressure, using the commercial computer package ANSYS 11.0. In order to achieve this aim, the dome was modelled and vibrated in air and then in water, before finally being vibrated under external water pressure. The results collected during each of the analyses were compared to the previous studies, and this demonstrated that ANSYS was a suitable program and produced accurate results for this type of analysis, together with excellent graphical displays. The analysis under external water pressure, clearly demonstrated that as external water pressure was increased, the resonant frequencies decreased and a type of dynamic buckling became likely; because the static buckling eigenmode was similar to the vibration eigenmode. ANSYS compared favourably with the in-house software, but had the advantage that it produced graphical displays. This also led to the identification of previously undetected meridional modes of vibration; which were not detected with the in-house software.

Nonlinear vibration of a hemispherical dome under external water pressure

Science.gov (United States)

Ross, C. T. F.; McLennan, A.; Little, A. P. F.

2011-07-01

The aim of this study was to analyse the behaviour of a hemi-spherical dome when vibrated under external water pressure, using the commercial computer package ANSYS 11.0. In order to achieve this aim, the dome was modelled and vibrated in air and then in water, before finally being vibrated under external water pressure. The results collected during each of the analyses were compared to the previous studies, and this demonstrated that ANSYS was a suitable program and produced accurate results for this type of analysis, together with excellent graphical displays. The analysis under external water pressure, clearly demonstrated that as external water pressure was increased, the resonant frequencies decreased and a type of dynamic buckling became likely; because the static buckling eigenmode was similar to the vibration eigenmode. ANSYS compared favourably with the in-house software, but had the advantage that it produced graphical displays. This also led to the identification of previously undetected meridional modes of vibration; which were not detected with the in-house software.

Sealing considerations for repository shafts in bedded and dome salt

International Nuclear Information System (INIS)

1981-12-01

The report reviews the geologic and hydrologic data base for penetration seal designs referenced to the Los Medanos bedded salt site in New Mexico and to four candidate salt domes in the Gulf Interior. Experience with existing shafts highlights the importance, for shaft decommissioning as well as operation, of achieving an adequate seal at and immediately below the top of salt. Possible construction procedures for repository shafts are reviewed, noting advantages and disadvantages with respect to repository sealing. At this stage, there does not appear to be a clear preference for excavation by drill and blast or by drilling. If conventional drill and blast methods are used, it may be necessary to grout in permeable zones above the salt. An important consideration with respect to sealing is that grouting operations (or freezing should it be used) should not establish connections between the top of salt and water-bearing zones higher in the stratigraphic section. Generally, it is concluded that Los Medanos and the dome salt sites are favorable candidate repository sites from the point of view of sealing

Deposits from the 12 July Dome Collapse and Explosive Activity at Soufriere Hills Volcano, 12-15 July 2003

Science.gov (United States)

Edmonds, M.; Herd, R.; Strutt, M.; Mann, C.

2003-12-01

A large dome collapse took place on 12-13 July 2003 at Soufriere Hills Volcano. This event was the largest in magnitude during the 1995-2003 eruption and involved over 120 million m3 andesite dome and talus material. The collapse took place over 18 hours and culminated in an explosive phase that continued intermittently until 15 July 2003. Prior to the collapse, the total volume of the dome was 230 million m3 and was made up of remnants of lava erupted 1997-2001, talus material and fresh andesite dome lava erupted during the last two years. Talus made up around 50% of the total dome volume. This paper describes and interprets the pyroclastic flow and airfall deposits from this event, using other monitoring data and empirical evidence to reconstruct the dome collapse. The airfall and pyroclastic flow deposits were studied in detail over the weeks following the collapse. Airfall deposits were studied at 45 locations around the island and 75 samples were collected for analysis. The surge deposit stretched over 10 km2 on land and 35 pits were dug at intervals through it. The sections were described and sampled, yielding a further 60 samples for grain size analysis. Further sampling was carried out on the block and ash deposits in the Tar River Valley and on the Tar River Fan. Pumices from the post-collapse explosion sequence were collected and their densities measured and mass coverage estimated. Deposit maps for airfall, lithics and pumices were constructed for all of the individual events and a map to show the distribution of the main surge unit was generated. The collapse was monitored in real-time using the MVO seismic network and observations from the field. The sequence of events was as follows. From 09:00 to 18:00, low-energy pyroclastic flows took place, confined to the Tar River Valley, which reached the sea at the mouth of Tar River. These flows gradually increased in energy throughout the day but were not associated with energetic, large surges. By 18:00 the

Effects of Cardinal Direction on Distribution and Populational Dynamism of Oak Leaf Roller (Tortrix viridana L. on Quercus infectoria Oliv. and Q. libani Lindl.

Directory of Open Access Journals (Sweden)

mohammadreza zargaran

2018-01-01

Full Text Available Introduction Various pests attack oak trees and in most cases heavily damage them. The European oak leaf roller is one of the important oak pests in some provinces of the Zagros, and it is an important pest of oak forests in some European and North African countries, as well as in Iraq and other regions of Iran. In Iran, it is scattered in the Zagros oak forests, especially in Kohkiluyeh and Boyer Ahmad, Lorestan, Chahar Mahal and Bakhtiari, Fars, and West Azarbaijan Provinces. Repeated removal of oak leaves, particularly by herbivores such as T. viridana in spring, reduces stored photosynthates in trees leading to their decreased diametrical growth. Materials and Methods The Ghabre-Hossein region (Piranshahr was selected as the field operations region because it is one of the most important infestation centers of the European oak leaf roller in the oak forests of West-Azerbaijan. The research was carried out in two consecutive years. Samples of larval instars were taken in early May. Since the sample plot in sampling methods can be points or lines (transects, the four cardinal directions were selected in this study and transects at 100 m intervals were located in each direction.To reduce sampling error, Aleppo (Quercus infectoria and Lebanon (Q. libani oak trees were selected for measurements that were similar in appearance and almost uniform with crowns or trunks aligned along the transects. In each studied tree, four suitable branches were selected (one in each cardinal direction, and the number of larvae from the tip of each branch to a length of 50 cm inwards was counted and recorded in forms prepared beforehand. Considering studies that were carried out regarding the biology of the pest, the larvae were counted in mid-May when all larvae were in their last (fifth instar. In all, 30 Aleppo and 30 Lebanon oak trees were selected in each cardinal direction, and four branches in each direction of these trees were measured. The survey method

Net Shape Spin Formed Cryogenic Aluminum Lithium Cryogenic Tank Domes for Lower Cost Higher Performance Launch Vehicles

Science.gov (United States)

Curreri, Peter A.; Hoffman, Eric; Domack, Marcia; Brewster, Jeb; Russell, Carolyn

2013-01-01

With the goal of lower cost (simplified manufacturing and lower part count) and higher performance (higher strength to weight alloys) the NASA Technical Maturation Program in 2006 funded a proposal to investigate spin forming of space launch vehicle cryogenic tank domes. The project funding continued under the NASA Exploration Technology Development Program through completion in FY12. The first phase of the project involved spin forming of eight, 1 meter diameter "path finder" domes. Half of these were processed using a concave spin form process (MT Aerospace, Augsburg Germany) and the other half using a convex process (Spincraft, Boston MA). The convex process has been used to produce the Ares Common Bulkhead and the concave process has been used to produce dome caps for the Space Shuttle light weight external tank and domes for the NASDA H2. Aluminum Lithium material was chosen because of its higher strength to weight ratio than the Aluminum 2219 baseline. Aluminum lithium, in order to obtain the desired temper (T8), requires a cold stretch after the solution heat treatment and quench. This requirement favors the concave spin form process which was selected for scale up. This paper describes the results of processing four, 5.5 meter diameter (upper stage scale) net shaped spin formed Aluminum Lithium domes. In order to allow scalability beyond the limits of foundry and rolling mills (about 12 foot width) the circular blank contained one friction stir weld (heavy lifter scales require a flat blank containing two welds). Mechanical properties data (tensile, fracture toughness, stress corrosion, and simulated service testing) for the parent metal and weld will also be discussed.

Final report on decommissioning of wells, boreholes, and tiltmeter sites, Gulf Coast Interior Salt Domes of Louisiana

Energy Technology Data Exchange (ETDEWEB)

1989-07-01

In the late 1970s, test holes were drilled in northern Louisiana in the vicinity of Vacherie and Rayburn`s Salt Domes as part of the Department of Energy`s (DOE) National Waste Terminal Storage (NWTS) (rename the Civilian Radioactive Waste Management (CRWM)) program. The purpose of the program was to evaluate the suitability of salt domes for long term storage or disposal of high-level nuclear waste. The Institute for Environmental Studies at Louisiana State University (IES/LSU) and Law Engineering Testing Company (LETCo) of Marietta, Georgia performed the initial field studies. In 1982, DOE awarded a contract to the Earth Technology Corporation (TETC) of Long Beach, California to continue the Gulf Coast Salt Dome studies. In 1986, DOE deferred salt domes from further consideration as repository sites. This report describes test well plugging and site abandonment activities performed by SWEC in accordance with Activity Plan (AP) 1--3, Well Plugging and Site Restoration of Work Sites in Louisiana. The objective of the work outlined in this AP was to return test sites to as near original condition as possible by plugging boreholes, removing equipment, regrading, and seeding. Appendices to this report contain forms required by State of Louisiana, used by SWEC to document decommissioning activities, and pertinent documentation related to lease/access agreements.

Final report on decommissioning of wells, boreholes, and tiltmeter sites, Gulf Coast Interior Salt Domes of Louisiana

International Nuclear Information System (INIS)

1989-07-01

In the late 1970s, test holes were drilled in northern Louisiana in the vicinity of Vacherie and Rayburn's Salt Domes as part of the Department of Energy's (DOE) National Waste Terminal Storage (NWTS) (rename the Civilian Radioactive Waste Management (CRWM)) program. The purpose of the program was to evaluate the suitability of salt domes for long term storage or disposal of high-level nuclear waste. The Institute for Environmental Studies at Louisiana State University (IES/LSU) and Law Engineering Testing Company (LETCo) of Marietta, Georgia performed the initial field studies. In 1982, DOE awarded a contract to the Earth Technology Corporation (TETC) of Long Beach, California to continue the Gulf Coast Salt Dome studies. In 1986, DOE deferred salt domes from further consideration as repository sites. This report describes test well plugging and site abandonment activities performed by SWEC in accordance with Activity Plan (AP) 1--3, Well Plugging and Site Restoration of Work Sites in Louisiana. The objective of the work outlined in this AP was to return test sites to as near original condition as possible by plugging boreholes, removing equipment, regrading, and seeding. Appendices to this report contain forms required by State of Louisiana, used by SWEC to document decommissioning activities, and pertinent documentation related to lease/access agreements

Pyroclastic flows generated by gravitational instability of the 1996-97 lava dome of Soufriere Hills Volcano, Montserrat

Science.gov (United States)

Cole, P.D.; Calder, E.S.; Druitt, T.H.; Hoblitt, R.; Robertson, R.; Sparks, R.S.J.; Young, S.R.

1998-01-01

Numerous pyroclastic flows were produced during 1996-97 by collapse of the growing andesitic lava dome at Soufriere Hills Volcano, Montserrat. Measured deposit volumes from these flows range from 0.2 to 9 ?? 106 m3. Flows range from discrete, single pulse events to sustained large scale dome collapse events. Flows entered the sea on the eastern and southern coasts, depositing large fans of material at the coast. Small runout distance (Soufriere Hills Volcano, Montserrat. Measured deposit volumes from these flows range from 0.2 to 9??106 m3. Flows range from discrete, single pulse events to sustained large scale dome collapse events. Flows entered the sea on the eastern and southern coasts, depositing large fans of material at the coast. Small runout distance (<1 km) flows had average flow front velocities in the order of 3-10 m/s while flow fronts of the larger runout distance flows (up to 6.5 km) advanced in the order of 15-30 m/s. Many flows were locally highly erosive. Field relations show that development of the fine grained ash cloud surge component was enhanced during the larger sustained events. Periods of elevated dome pyroclastic flow productivity and sustained collapse events are linked to pulses of high magma extrusion rates.

Stable boundary-layer regimes at dome C, Antarctica : observation and analysis

NARCIS (Netherlands)

Vignon, E.; van de Wiel, B.J.H.; van Hooijdonk, I.G.S.; Genthon, C.; van der Linden, S.J.A.; van Hooft, J.A.; Baas, P.; Maurel, W.; Traullé, O.; Casasanta, G.

2017-01-01

Investigation of meteorological measurements along a 45 m tower at Dome C on the high East Antarctic Plateau revealed two distinct stable boundary layer (SBL) regimes at this location. The first regime is characterized by strong winds and continuous turbulence. It results in full vertical coupling

Radio Echo Sounding (RES investigations at Talos Dome (East Antarctica: bedrock topography and ice thickness

Directory of Open Access Journals (Sweden)

I. E. Tabacco

2003-06-01

Full Text Available Radio echo sounding measurements were collected during two Antarctic expeditions to determine the ice thickness and the sub-glacial morphology of Talos Dome in the region around 72°48'S; 159°06'E (about 6400 km2 on the edge of the East Antarctic plateau adjacent to Victoria Land in the western Ross Sea sector. The increasing interest in this region is due to the fact that in this area the ice accumulation is higher than in other sites in East Antarctica. Because of this, Talos Dome could be a new site for a project of a deep ice core drilling to obtain information on climate changes near the coast of Antarctica. In this frame, the knowledge of the bedrock topography is of great importance to choose the best location for the drilling site. In this paper, airborne radio echo sounding results from two Antarctic expeditions (1997 and 1999 are presented. Bedrock topography in bi- and three-dimensions for the Talos Dome region are discussed.

Optimizing the night time with dome vents and SNR-QSO at CFHT

Science.gov (United States)

Devost, Daniel; Mahoney, Billy; Moutou, Claire; CFHT QSO Team, CFHT software Group

2017-06-01

Night time is a precious and costly commodity and it is important to get everything we can out of every second of every night of observing. In 2012 the Canada-France-Hawaii Telescope started operating 12 new vent doors installed on the dome over the course of the previous two years. The project was highly successful and seeing measurements show that venting the dome greatly enhances image quality at the focal plane. In order to capitalize on the gains brought by the new vents, the observatory started exploring a new mode of observation called SNR-QSO. This mode consist of a new implementation inside our Queued Service Observation (QSO) system. Exposure times are adjusted for each frame depending on the weather conditions in order to reach a specific depth, Signal to Noise Ratio (SNR) at a certain magnitude. The goal of this new mode is to capitalize on the exquisite seeing provided by Maunakea, complemented by the minimized dome turbulence, to use the least amount of time to reach the depth required by the science programs. Specific implementations were successfully tested on two different instruments, our wide field camera MegaCam and our high resolution spectrograph ESPaDOnS. I will present the methods used for each instrument to achieve SNR observing and the gains produced by these new observing modes in order to reach the scientific goals of accepted programs in a shorter amount of time.

Assessment of Real-Time Compaction Quality Test Indexes for Rockfill Material Based on Roller Vibratory Acceleration Analysis

Directory of Open Access Journals (Sweden)

Tianbo Hua

2018-01-01

Full Text Available Compaction quality is directly related to the structure and seepage stability of a rockfill dam. To timely and accurately test the compaction quality of the rockfill material, four real-time test indexes were chosen to characterize the soil compaction degree based on the analysis of roller vibratory acceleration, including acceleration peak value (ap, acceleration root mean square value (arms, crest factor value (CF, and compaction meter value (CMV. To determine which of these indexes is the most appropriate, a two-part field compaction experiment was conducted using a vibratory roller in different filling zones of the dam body. Data on rolling parameters, real-time test indexes, and compaction quality indexes were collected to perform statistical regression analyses. Combined with the spectrum analysis of the acceleration signal, it was found that the CF index best characterizes the compaction degree of the rockfill material among the four indexes. Furthermore, the quantitative relations between the real-time index and compaction quality index were established to determine the control criterion of CF, which can instruct the site work of compaction quality control in the rockfill rolling process.

Adaptive Technology Application for Vibration-Based Diagnostics of Roller Bearings on Industrial Plants

Directory of Open Access Journals (Sweden)

Mironov Aleksey

2014-09-01

Full Text Available Roller bearings are widely used in equipment of different applications; therefore, the issues related to the assessment of bearing technical state and localization of bearing faults are quite important and relevant. The reason is that technical state of a bearing is a critical component, which determines efficiency of a mechanism or equipment. For bearings inspection and diagnostics, various methods of vibration-based diagnostics are used. The adaptive technology for vibration-based diagnostics developed in „D un D centrs” is an effective tool for evaluation of technical state of bearings in operation compared to the existing SKF method.

Investigation of the utility of Gulf Coast salt domes for the storage or disposal of radioactive wastes

International Nuclear Information System (INIS)

Martinez, J.D.; Thoms, R.L.; Kupfer, D.H.

1976-01-01

Analysis of tectonic, geohydrologic, and cultural data led to the selection of three salt domes (Vacherie, Rayburn's, Prothro) in the North Louisiana Basin and three (Keechi, Mt. Sylvan, Palestine) in the Northeast Texas Basin. Results of the tectonic stability studies (monitoring of dome movement, quaternary, Mesozoic and Tertiary, seismic, corehole in Vacherie) and hydrologic stability studies (numerical modeling, caprock, mine leaks) are discussed in detail and recommendations for further study are given

Investigation of the utility of Gulf Coast salt domes for the storage or disposal of radioactive wastes

Energy Technology Data Exchange (ETDEWEB)

Martinez, J.D.; Thoms, R.L.; Kupfer, D.H.

1976-09-30

Analysis of tectonic, geohydrologic, and cultural data led to the selection of three salt domes (Vacherie, Rayburn's, Prothro) in the North Louisiana Basin and three (Keechi, Mt. Sylvan, Palestine) in the Northeast Texas Basin. Results of the tectonic stability studies (monitoring of dome movement, quaternary, Mesozoic and Tertiary, seismic, corehole in Vacherie) and hydrologic stability studies (numerical modeling, caprock, mine leaks) are discussed in detail and recommendations for further study are given. (DLC)

Evaluating links between deformation, topography and surface temperature at volcanic domes: Results from a multi-sensor study at Volcán de Colima, Mexico

Science.gov (United States)

Salzer, Jacqueline T.; Milillo, Pietro; Varley, Nick; Perissin, Daniele; Pantaleo, Michele; Walter, Thomas R.

2017-12-01

Dome building activity is common at many volcanoes and due to the gravitational instability, a dome represents one of the most hazardous volcanic phenomena. Shallow volcanic processes as well as rheological and structural changes of the dome affecting the fluid transport have been linked to transitions in eruptive activity. Also, hydrothermal alteration may affect the structural integrity of the dome, increasing the potential for collapse. However, mapping the deformation and details of fluid escape at the summit of steep sloped volcanoes and integrating these with other types of data is challenging due to difficult access and poor coverage. Here we present for the first time the near-vertical and near-horizontal surface deformation field of a quiescent summit dome and the relationships with degassing and topographic patterns. Our results are derived from high resolution satellite radar interferometry (InSAR) time series based on a year of TerraSAR-X SpotLight acquisitions and Structure from Motion (SfM) processing of overflight infrared data at Volcán de Colima, Mexico. The identified deformation is dominated by localized heterogeneous subsidence of the summit dome exceeding rates of 15 cm/yr, and strongly decreasing over the year 2012, up to the renewal of explosive and extrusive activity in early 2013. We tentatively attribute the deformation to the degassing, cooling and contraction of the dome and shallow conduit material. We also find that the results strongly differ depending on the chosen InSAR time series method, which potentially overprints the true physical complexities of small scale, shallow deformation processes. The combined interpretation of the deformation and infrared data reveals a complex spatial relationship between the degassing pathways and the deformation. While we observe no deformation across the crater rim fumaroles, discontinuities in the deformation field are more commonly observed around the dome rim fumaroles and occasionally on the

Decreasing inventory of a cement factory roller mill parts using reliability centered maintenance method

Science.gov (United States)

Witantyo; Rindiyah, Anita

2018-03-01

According to data from maintenance planning and control, it was obtained that highest inventory value is non-routine components. Maintenance components are components which procured based on maintenance activities. The problem happens because there is no synchronization between maintenance activities and the components required. Reliability Centered Maintenance method is used to overcome the problem by reevaluating maintenance activities required components. The case chosen is roller mill system because it has the highest unscheduled downtime record. Components required for each maintenance activities will be determined by its failure distribution, so the number of components needed could be predicted. Moreover, those components will be reclassified from routine component to be non-routine component, so the procurement could be carried out regularly. Based on the conducted analysis, failure happens in almost every maintenance task are classified to become scheduled on condition task, scheduled discard task, schedule restoration task and no schedule maintenance. From 87 used components for maintenance activities are evaluated and there 19 components that experience reclassification from non-routine components to routine components. Then the reliability and need of those components were calculated for one-year operation period. Based on this invention, it is suggested to change all of the components in overhaul activity to increase the reliability of roller mill system. Besides, the inventory system should follow maintenance schedule and the number of required components in maintenance activity so the value of procurement will be decreased and the reliability system will increase.

Geometric and Optic Characterization of a Hemispherical Dome Port for Underwater Photogrammetry

Directory of Open Access Journals (Sweden)

Fabio Menna

2016-01-01

Full Text Available The popularity of automatic photogrammetric techniques has promoted many experiments in underwater scenarios leading to quite impressive visual results, even by non-experts. Despite these achievements, a deep understanding of camera and lens behaviors as well as optical phenomena involved in underwater operations is fundamental to better plan field campaigns and anticipate the achievable results. The paper presents a geometric investigation of a consumer grade underwater camera housing, manufactured by NiMAR and equipped with a 7′′ dome port. After a review of flat and dome ports, the work analyzes, using simulations and real experiments, the main optical phenomena involved when operating a camera underwater. Specific aspects which deal with photogrammetric acquisitions are considered with some tests in laboratory and in a swimming pool. Results and considerations are shown and commented.

Performance Analysis of Functionally Graded Coatings in Contact with Cylindrical Rollers

Directory of Open Access Journals (Sweden)

Reza Jahedi

2015-01-01

Full Text Available This work presents finite element analysis (FEA and results for rolling contact of a cylindrical roller on an elastic substrate coated by functionally graded material (FGM. The rolling process and the graded coating material property and layers arrangement are modeled using finite element codes which lead to a new methodology. This novel methodology provides a trend in determining surface contact stresses, deformations, contact zones, and energy dissipation through the contact area. Effects of stiffness ratio, friction, and exponentially variation of material property on the contact stresses and deformations are studied. Some of the results are verified with analytical solutions. The study results may be beneficial in graded coated cylindrical components analysis against rolling contact failure and wear.

Failure of the chassis of roller skates for agonistic figure skating