Science.gov

Sample records for fissure type vents

  1. Tectono-volcanic control of fissure type vents for the 28 Ma Panalillo ignimbrite in the Villa de Reyes Graben, San Luis Potosí, México.

    NASA Astrophysics Data System (ADS)

    Tristán-González, Margarito; Labarthe-Hernández, Guillermo; Aguirre-Díaz, Gerardo J.; Aguillón-Robles, Alfredo

    2008-10-01

    The volcano-tectonic events at the Villa de Reyes Graben (VRG), in the southern Sierra Madre Occidental, Mexico, include 1) a regional NNE fault system developed before 32 Ma, 2) this pre-32 Ma faulting controlled the emplacement of 31.5 Ma dacitic domes, 3) NE faulting at 28 Ma that displaced the 31.5 Ma dacitic domes and formed the VRG, as well as the oblique grabens of Bledos and Enramadas oriented NW, 4) emplacement of Panalillo ignimbrite at 28 Ma filling the VRG and erupting from fissures related to the oblique grabens, and eruption of Placa basalt apparently also from fault-controlled vents.

  2. Phimosis with Preputial Fissures as a Predictor of Undiagnosed Type 2 Diabetes in Adults.

    PubMed

    Huang, Yun-Ching; Huang, Yao-Kuang; Chen, Chih-Shou; Shindel, Alan W; Wu, Ching-Fang; Lin, Jian-Hui; Chiu, Kuo-Hsiung; Yang, Tzu-Hsin; Shi, Chung-Sheng

    2016-03-01

    Diabetes is usually asymptomatic in its early stage. Early diagnosis may improve outcomes by enabling initiation of treatment before end organ damage has progressed. The aim of this study was to determine whether the clinical sign of phimosis with preputial fissures is predictive of type 2 diabetes in patients not previously diagnosed with diabetes. Twenty-eight patients with acquired phimosis and preputial fissures were collected prospectively. Twenty-eight controls with acquired phimosis without preputial fissures were selected. Statistically significant differences were found in body mass index, random plasma glucose, glucosuria and glycosylated haemoglobin levels, but not in age, family history of diabetes, hypertension and classical hyperglycaemic symptoms. Diabetes was confirmed in all 28 patients in the preputial fissures group, but only 2 (7.1%) patients in the non-preputial fissures group (p < 0.0001). In conclusion, phimosis with preputial fissures may be a specific sign of undiagnosed diabetes mellitus. PMID:26349852

  3. Relationships between lava types, seafloor morphology, and the occurrence of hydrothermal venting in the ASHES vent field of Axial Volcano. [Axial Seamount Hydrothermal Emission Study

    SciTech Connect

    Hammond, S.R. )

    1990-08-10

    Deep-towed and submersible photographic surveys within the caldera of Axial Volcano have been integrated with high-resolution bathmetry to produce a geological map of the most active vent field in the caldera. Locations for over 2,000 photographs in and near the vent field were determined using a seafloor transponder network. Then each photograph was described utilizing a classification system which provides detailed information concerning lava type, hydrothermal activity, sediment cover, geological structure, and biology. Resulting data were entered into a digital data base, and computer-generated maps were created that portray spatial relationships between selected geological variables. In general, the entire ASHES field is characterized by pervasive low-temperature venting. The most vigorous venting is concentrated in an approximately 80 m {times} 80 m area where there are several high-temperature vents including some which are producing high-temperature vapor-phase fluids derived from a boiling hydrothermal system. Lava types within the ASHES vent field are grouped into three distinct morphologies: (1) smooth (flat-surfaced, ropy, and whorled) sheet flows, (2) lobate flows, and (3) jumbled-sheet flows. The most intense hydrothermal venting is concentrated in the smooth sheet flows and the lobate flows. The location of the ASHES field is mainly attributable to faulting which defines the southwest caldera wall, but the concentration of intense venting appears to be related also to the spatial distribution of lava types in the vent field and their contrasting permeabilities. Other structural trends of faults and fissures within the field also influence the location of individual events.

  4. Near-Vent, Fissure-Fed Lava Channel Network Morphologies in the Kīlauea December 1974 Flow: Implications for Differentiating Lava Construction From Fluvial Erosion on Planets

    NASA Astrophysics Data System (ADS)

    Bleacher, J. E.

    2015-12-01

    Streamlined islands are often assumed to be the product of erosion by water and are cited as evidence of aqueous flows on Mars. However, lava can build streamlined islands in a manner that is more easily explained by flow thickening followed by partial drainage of preferred lava pathways. Kīlauea's December 1974 (D1974) flow was emplaced as a broad sheet-like flow from a series of en echelon fissures across an older hummocky pāhoehoe tumulus field. The lavas surrounded the tumuli and coalesced to fill a topographic low near the basal scarp of the Koae Fault System. As these obstacles were inundated by the D1974 flow, the lava preferentially cooled around the tumuli to form a higher viscosity zone beneath a smooth crust. Stagnation of these thinner, cooler, and more viscous zones focused the flow into a series of preferred lava pathways located between the stagnant islands. Changes in the local discharge rate disrupted the crust of the flow above the lower viscosity pathways. Older tumuli adjacent to the D1974 flow display the same relief as the flow's islands and uncovered portions of this older flow are exposed at the tops of many islands, supporting an interpretation that islands were anchored by high-standing pre-flow tumuli. As the local lava supply waned, partial drainage of the preferred pathways occurred between the higher-standing surfaces anchored to the older tumuli. The resulting morphology consists of a relatively smooth flow field with thin margins that is dissected by depressed pathways or channels. This morphology resembles an erosional surface incised into a smooth plain, but actually represents an initial constructional process followed by partial drainage within a viscous lava flow. Many other Hawaiian rift zone, fissure-fed flow fields display comparable morphologies in the near vent facies, including islands, terraces, thin flow margins and a lack of well defined topographic levees along channels. Thus, branching channel networks and

  5. Submarine fissure eruptions and hydrothermal vents on the southern Juan de Fuca Ridge: preliminary observations from the submersible Alvin.

    USGS Publications Warehouse

    Normark, W.R.

    1986-01-01

    The submersible Alvin was used to investigate 3 active hydrothermal discharge sites along the S Juan de Fuca Ridge in September 1984. The hydrothermal zones occur within a 10-30m-deep, 30-50m-wide cleft marking the center of the axial valley. This cleft is the eruptive locus for the axial valley. The hydrothermal vents coincide with the main eruptive vents along the cleft. Each hydrothermal zone has multiple discharge sites extending as much as 500m along the cleft. Sulfide deposits occur as clusters (15-100m2 area) of small chimneys (= or <2m high) and as individual and clustered fields of large, branched chimneys (= or <10m high). Recovered sulfide samples are predominantly the tops of chimneys and spires and typically contain more than 80% sphalerite and wurtzite with minor pyrrhotite, pyrite, marcasite, isocubanite, chalcopyrite, anhydrite, anhydrite, and amorphous silica. The associated hydrothermal fluids have the highest chlorinity of any reported to date.-Authors

  6. Anal fissure.

    PubMed

    Schlichtemeier, Steven; Engel, Alexander

    2016-02-01

    An anal fissure is a common, mostly benign, condition that can be acute or chronic. The diagnosis is usually made on history and physical examination, but further investigations are sometimes necessary. Primary fissures are usually benign and located in the posterior or anterior position. Secondary fissures are lateral or multiple and often indicate a more serious underlying pathology. The management of primary anal fissures is generally non-operative and includes increased dietary fibre, sitz baths, topical ointments and botulinum toxin injections. If these treatments are ineffective the patient will need a surgical referral. Secondary anal fissures require further investigation. Multidisciplinary management is preferable and is essential in the case of malignancy. PMID:27041801

  7. Anal fissure

    PubMed Central

    Schlichtemeier, Steven; Engel, Alexander

    2016-01-01

    SUMMARY An anal fissure is a common, mostly benign, condition that can be acute or chronic. The diagnosis is usually made on history and physical examination, but further investigations are sometimes necessary. Primary fissures are usually benign and located in the posterior or anterior position. Secondary fissures are lateral or multiple and often indicate a more serious underlying pathology. The management of primary anal fissures is generally non-operative and includes increased dietary fibre, sitz baths, topical ointments and botulinum toxin injections. If these treatments are ineffective the patient will need a surgical referral. Secondary anal fissures require further investigation. Multidisciplinary management is preferable and is essential in the case of malignancy. PMID:27041801

  8. Chabazite in spodumene-bearing Alpine-type fissure veins from Hiddenite, North Carolina, USA

    NASA Astrophysics Data System (ADS)

    Wise, Michael A.

    2009-07-01

    Alpine-type fissure vein mineralization in the Hiddenite area of western North Carolina, USA consists mostly of quartz, but locally contains Cr-bearing beryl (emerald) or Cr-bearing spodumene (hiddenite). These gem minerals occur in mineral-lined cavities and may be accompanied by euhedral crystals of quartz, calcite, muscovite, rutile, albite, pyrite, siderite and dolomite. Chabazite-Ca occurs as a late stage phase in spodumene-bearing veins, but is absent in emerald-bearing veins. Chabazite-Ca occurs as simple penetrating twins of pseudocubic rhombohedra and as the lens-shaped variety, phacolite. Chabazite-Ca from Hiddenite contains minor amounts of Na, Mg, Fe and K. Phacolitic chabazite-Ca shows Fe-enriched but Mg-depleted cores relative to the rims. Chemical zoning is absent in rhombohedral chabazite. The Hiddenite chabazite apparently precipitated under low temperature (< 250°C) and low pressure (< 2 kbar) conditions during the waning stages of crystallization of an alkaline hydrothermal fluid.

  9. Shallow Subsurface Structures of Volcanic Fissures

    NASA Astrophysics Data System (ADS)

    Parcheta, C. E.; Nash, J.; Mitchell, K. L.; Parness, A.

    2015-12-01

    Volcanic fissure vents are a difficult geologic feature to quantify. They are often too thin to document in detail with seismology or remote geophysical methods. Additionally, lava flows, lava drain back, or collapsed rampart blocks typically conceal a fissure's surface expression. For exposed fissures, quantifying the surface (let along sub0surface) geometric expression can become an overwhelming and time-consuming task given the non-uniform distribution of wall irregularities, drain back textures, and the larger scale sinuosity of the whole fissure system. We developed (and previously presented) VolcanoBot to acquire robust characteristic data of fissure geometries by going inside accessible fissures after an eruption ends and the fissure cools off to <50 C. Data from VolcanoBot documents the fissure conduit geometry with a near-IR structured light sensor, and reproduces the 3d structures to cm-scale accuracy. Here we present a comparison of shallow subsurface structures (<30 m depth) within the Mauna Ulu fissure system and their counterpart features at the vent-to-ground-surface interface. While we have not mapped enough length of the fissure to document sinuosity at depth, we see a self-similar pattern of irregularities on the fissure walls throughout the entire shallow subsurface, implying a fracture mechanical origin similar to faults. These irregularities are, on average, 1 m across and protrude 30 cm into the drained fissure. This is significantly larger than the 10% wall roughness addressed in the engineering literature on fluid dynamics, and implies that magma fluid dynamics during fissure eruptions are probably not as passive nor as simple as previously thought. In some locations, it is possible to match piercing points across the fissure walls, where the dike broke the wall rock in order to propagate upwards, yet in other locations there are erosional cavities, again, implying complex fluid dynamics in the shallow sub-surface during fissure eruptions.

  10. Evaluation of different types of enamel conditioning before application of a fissure sealant.

    PubMed

    Ciucchi, Philip; Neuhaus, Klaus W; Emerich, Marta; Peutzfeldt, Anne; Lussi, Adrian

    2015-01-01

    The aim of the study was to compare fissure sealant quality after mechanical conditioning of erbium-doped yttrium aluminium garnet (Er:YAG) laser or air abrasion prior to chemical conditioning of phosphoric acid etching or of a self-etch adhesive. Twenty-five permanent molars were initially divided into three groups: control group (n = 5), phosphoric acid etching; test group 1 (n = 10), air abrasion; and test group 2, (n = 10) Er:YAG laser. After mechanical conditioning, the test group teeth were sectioned buccolingually and the occlusal surface of one half tooth (equal to one sample) was acid etched, while a self-etch adhesive was applied on the other half. The fissure system of each sample was sealed, thermo-cycled and immersed in 5% methylene dye for 24 h. Each sample was sectioned buccolingually, and one slice was analysed microscopically. Using specialized software microleakage, unfilled margin, sealant failure and unfilled area proportions were calculated. A nonparametric ANOVA model was applied to compare the Er:YAG treatment with that of air abrasion and the self-etch adhesive with phosphoric acid (α = 0.05). Test groups were compared to the control group using Wilcoxon rank sum tests (α = 0.05). The control group displayed significantly lower microleakage but higher unfilled area proportions than the Er:YAG laser + self-etch adhesive group and displayed significantly higher unfilled margin and unfilled area proportions than the air-abrasion + self-etch adhesive group. There was no statistically significant difference in the quality of sealants applied in fissures treated with either Er:YAG laser or air abrasion prior to phosphoric acid etching, nor in the quality of sealants applied in fissures treated with either self-etch adhesive or phosphoric acid following Er:YAG or air-abrasion treatment.

  11. Microleakage and penetration depth of three types of materials in fissure sealant: self-etching primer vs etching: an in vitro study.

    PubMed

    Gillet, D; Nancy, J; Dupuis, V; Dorignac, G

    2002-01-01

    Clinical preventive procedures must be done after a risk assessment. One of the risk factors is the occlusal morphology of the posterior teeth. These caries-free fissures must be sealed. This first in vitro experimentation of the study evaluated the microleakage and the penetration depth of three types of materials by Vivadent: Helioseal F, Tetric, Tetric Flow. The teeth were etched with phosphoric acid and bonded using a one bottle bonding in order to determine the best material for the sealing of the fissure. The depth of penetration of fuschine dye as well as that of the tested material was measured with a grid. The results, compared to the depth of the fissures, are expressed in percentage of penetration. The results were as follows: penetration of fuschine dye: 0% for the 2 composites, 100% for Helioseal F; penetration of the materials: 96.90% for Helioseal F, 70.82 for Tetric and 86.10 for Tetric Flow (significant difference, Wilcoxon test = 0.0105). In this first in vitro study, Tetric Flow shows no microleakage and is more efficient when compared to Helioseal F and Tetric in obturating deep fissures of non carious bicuspids. The second experiment of the study evaluated the microleakage and the penetration depth of Tetric Flow when it is bonded by two different methods: Group 1: total etch (phosphoric acid) and Scotch-bond 1 (3M), and Group 2: self-etching primer with Prompt (Espe). There was no significant difference (p > 0.03) between classical bonding vs self-etching primer. The self-etching primer Prompt is very efficient vs phosphoric acid in obturating the fissures of non carious bicuspids with Tetric Flow. It is concluded that for prevention by sealing, using a flowable ceromer (Tetric Flow) with the self-etching (Prompt), is a really good technique.

  12. Radar Observations of Fissure-fed Basaltic Lava Flows, Craters of the Moon, Idaho

    NASA Technical Reports Server (NTRS)

    Martel, L.; Greeley, R.

    1985-01-01

    Changes in surface roughness of lava flows, estimated from dual polarization, synthetic aperture, X and L band side-looking airborne radar images, were tested as a means of locating fissure vent areas. If lava textures proess from smooth, near-vent shelly pahoehoe to hummocky pahoehoe to aa with distance from fissure vents, then radr images of the lava flows would show a progression from dark to brighter tones due to the flows' increasing radar back-scatter.

  13. Video Observations by Telepresence Reveal Two Types of Hydrothermal Venting on Kawio Barat Seamount

    NASA Astrophysics Data System (ADS)

    Butterfield, D. A.; Holden, J. F.; Shank, T. M.; Tunnicliffe, V.; Sherrin, J.; Herrera, S.; Baker, E. T.; Lovalvo, D.; Makarim, S.; Malik, M. A.; Wirasantosa, S.; Hammond, S. R.

    2010-12-01

    The INDEX-SATAL 2010 expedition began an international exploration of the seafloor in Indonesian waters using the methodology of telepresence, conducting EM302 multibeam mapping, water column CTD, and ROV high-definition video operations and sending data back to Exploration Command Centers in Indonesia and Seattle. Science observers in other locations in the US and Canada were engaged in real-time observations and interpretation of results. One mission goal was to locate hydrothermal or volcanic activity. Intense light scattering and redox potential measurements in the water column over Kawio Barat (KB)indicated a high level of hydrothermal activity, and direct video observations confirmed venting near the summit. None of the other volcanic features west of the Sangihe arc that were investigated during the mission had confirmed hydrothermal activity. ROV capabilities did not include physical sampling or temperature measurement, so our interpretation is based on visual comparison to other known sites. The steep western flank of KB from 2000 m depth to the summit (1850 m) has many areas of white and orange staining on exposed rocks, with some elemental sulfur, and broad areas covered with dark volcaniclastic sand, but no active venting was seen. KB has a summit ridge running WNW-ESE, with a major cross-cutting ridge on the western portion of the summit. Hydrothermal activity is concentrated near the eastern side of this intersection, on both the northern and southern sides of the summit ridge. Venting on the northern side of the summit ridge is characterized by intense white particle-rich fluids emanating directly from the rocky substrate with frozen flows of elemental sulfur down slope. This type of venting is visually very similar to the venting seen on NW Rota-1, an actively erupting volcano in the Mariana arc, and suggests that KB is actively releasing magmatic gases rich in sulfur dioxide to produce the elemental sulfur flows, inferred fine particulate sulfur

  14. The architecture and shallow conduits of Laki-type pyroclastic cones: insights into a basaltic fissure eruption

    NASA Astrophysics Data System (ADS)

    Reynolds, P.; Brown, R. J.; Thordarson, T.; Llewellin, E. W.

    2016-05-01

    Pyroclastic cones built along basaltic fissures provide important volcanological information, but it is often difficult to examine the early-erupted products due to burial by later products. Furthermore, it is rare to see the link between the feeder dyke and overlying cone fully exposed. In this study, we detail the architecture of a hybrid spatter cone, scoria half-cone and feeder dyke that has been dissected to below the pre-eruption surface by glacial floods. The cones were constructed during the 6-8 ka Rauðuborgir-Kvensöðul fissure eruption in North Iceland during Hawaiian- and Strombolian-style activities. Widening of their feeder dyke in the shallow sub-surface to produce an upward flaring morphology was accommodated by country rock removal and elastic host rock deformation. Ballistic calculations and stratigraphic relationships indicate that the scoria half-cone was constructed early in the eruption from the deposits of a lava fountain ~100 m high. A decline in fountain height and the generation of abundant welded deposits resulted in the formation of a nested spatter cone within the scoria half-cone. The cones are similar in structure and size to the hybrid scoria and spatter cones produced during the 15-km3 1783 Laki eruption and serve as a valuable window into the construction of pyroclastic edifices during basaltic fissure eruptions.

  15. Anal fissure - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100154.htm Anal fissure - series—Normal anatomy To use the sharing ... rectum through which passes stool during defecation. The anal sphincter is a critical mechanism for control of ...

  16. Engineering a robotic approach to mapping exposed volcanic fissures

    NASA Astrophysics Data System (ADS)

    Parcheta, C. E.; Parness, A.; Mitchell, K. L.

    2014-12-01

    Field geology provides a framework for advanced computer models and theoretical calculations of volcanic systems. Some field terrains, though, are poorly preserved or accessible, making documentation, quantification, and investigation impossible. Over 200 volcanologists at the 2012 Kona Chapman Conference on volcanology agreed that and important step forward in the field over the next 100 years should address the realistic size and shape of volcanic conduits. The 1969 Mauna Ulu eruption of Kīlauea provides a unique opportunity to document volcanic fissure conduits, thus, we have an ideal location to begin addressing this topic and provide data on these geometries. Exposed fissures can be mapped with robotics using machine vision. In order to test the hypothesis that fissures have irregularities with depth that will influence their fluid dynamical behavior, we must first map the fissure vents and shallow conduit to deci- or centimeter scale. We have designed, constructed, and field-tested the first version of a robotic device that will image an exposed volcanic fissure in three dimensions. The design phase included three steps: 1) create the payload harness and protective shell to prevent damage to the electronics and robot, 2) construct a circuit board to have the electronics communicate with a surface-based computer, and 3) prototype wheel shapes that can handle a variety of volcanic rock textures. The robot's mechanical parts were built using 3d printing, milling, casting and laser cutting techniques, and the electronics were assembled from off the shelf components. The testing phase took place at Mauna Ulu, Kīlauea, Hawai'i, from May 5 - 9, 2014. Many valuable design lessons were learned during the week, and the first ever 3D map from inside a volcanic fissure were successfully collected. Three vents had between 25% and 95% of their internal surfaces imaged. A fourth location, a non-eruptive crack (possibly a fault line) had two transects imaging the textures

  17. Accessory fissures of the lung

    SciTech Connect

    Godwin, D.; Tarver, R.D.

    1985-01-01

    Accessory fissures of the lung are commonly observed in lung specimens, but are often unappreciated or misinterpreted in radiographs and computer tomographic (CT) scans. They usually occur at the boundaries between bronchopulmonary segments. Most common are the inferior accessory fissure, which demarcates the medial basal segment; the superior accessory fissure, which demarcates the superior segment; and the left minor fissure, which demarcates the lingula. This essay will illustrate the findings of the common accessory fissures both on plain radiographs and on CT scans.

  18. Sonar backscatter differentiation of dominant macrohabitat types in a hydrothermal vent field.

    PubMed

    Durand, Sébastien; Legendre, Pierre; Juniper, S Kim

    2006-08-01

    Over the past 20 years, sonar remote sensing has opened ways of acquiring new spatial information on seafloor habitat and ecosystem properties. While some researchers are presently working to improve sonar methods so that broad-scale high-definition surveys can be effectively conducted for management purposes, others are trying to use these surveying techniques in more local areas. Because ecosystem management is scale-dependent, there is a need to acquire spatiotemporal knowledge over various scales to bridge the gap between already-acquired point-source data and information available at broader scales. Using a 675-kHz single-pencil-beam sonar mounted on the remotely operated vehicle ROPOS, 2200 m deep on the Juan de Fuca Ridge, East Pacific Rise, five dominant habitat types located in a hydrothermal vent field were identified and characterized by their sonar signatures. The data, collected at different altitudes from 1 to 10 m above the seafloor, were depth-normalized. We compared three ways of handling the echoes embedded in the backscatters to detect and differentiate the five habitat types; we examined the influence of footprint size on the discrimination capacity of the three methods; and we identified key variables, derived from echoes that characterize each habitat type. The first method used a set of variables describing echo shapes, and the second method used as variables the power intensity values found within the echoes, whereas the last method combined all these variables. Canonical discriminant analysis was used to discriminate among the five habitat types using the three methods. The discriminant models were constructed using 70% of the data while the remaining 30% were used for validation. The results showed that footprints 20-30 cm in diameter included a sufficient amount of spatial variation to make the sonar signatures sensitive to the habitat types, producing on average 82% correct classification. Smaller footprints produced lower percentages of

  19. Newer Classification System for Fissured Tongue: An Epidemiological Approach

    PubMed Central

    Sudarshan, Ramachandran; Sree Vijayabala, G.; Samata, Y.; Ravikiran, A.

    2015-01-01

    Introduction. Fissured tongue is a commonly encountered tongue disorder in dental practice. But there is a lack of data on different pattern, severity, and association of fissuring with various systemic disorders and other tongue anomalies. This study attempts to establish a classification system for fissured tongue and to know the correlation with the systemic health and other disorders of the tongue. Materials and Methods. A total of 1000 subjects between the age groups of 10 and 80 years were included in the study. Pattern of fissuring, allied systemic diseases, and related tongue anomalies were tabulated. Results. Out of 1000 subjects, 387 subjects presented with fissured tongue. Out of 387 subjects, hypertension was present in 57 cases, 18 subjects had diabetes, and 3 subjects had both hypertension and diabetes. Central longitudinal type was found to be the most common type of tongue fissuring. Conclusion. Fissured tongue has been found to be associated with certain systemic disease and further researches are required to know positive correlation. If a correlation exists, such disorders could be diagnosed earlier by identifying fissured tongue at an earlier age. PMID:26457087

  20. A Geophysical Study of Fissures in Pahrump, Nevada

    NASA Astrophysics Data System (ADS)

    Hirsch, A. C.; McEwan, M. J.; Howley, R. A.; Mehling, J. B.; Snelson, C. M.; Drohan, P.

    2004-12-01

    Earth fissures are surface expressions of deep fracturing subsidence systems caused by groundwater withdrawl greater than aquifer recharge. This type of subsidence is most common in arid environments of the south western U.S. such as, Las Vegas, NV, Phoenix, AZ, and areas in New Mexico. In addition, fissures have recently been identified in the Pahrump Valley in southwestern Nevada just west of Las Vegas. The city of Pahrump has experienced an increase in population and economic growth. This growth has lead to a higher demand in the use of the areas natural resources. One major concern is groundwater pumping and over-watering of the land surface. Pahrump has experienced significant differential subsidence within the valley causing significant structural damage to infrastructure. This differential subsidence is most readily identified by its surface expression as fissures. Earth fissures are not only shallow surface features but can be 10's of meters deep and 100's of meters long. These ground failures can be exacerbated by faults at depth, shallow bedrock, and/or differential compaction. However, the most significant cause is from groundwater withdrawl. Several geophysical methods were performed on the fissures to better understand their subsurface expression, trend, and ultimately their affect on the city of Pahrump. Seismic refraction, reflection, ground penetrating radar (GPR), and gravity measurements were performed on the fissures and surrounding area including local faults. Our initial studies show the fissures propagating for long distances, in a variety of shapes, and trending in a north-south direction. Initial GPR studies show high fissure reflections at approximately 1 and 1.5 meters along with general slumping features below these reflections. Fissures are an unmitigatable problem. Our results will help identify fissures in the area that do not have a surface expression as well as mapping the current fissures and their extent. These results can be used

  1. A visualization system for CT based pulmonary fissure analysis

    NASA Astrophysics Data System (ADS)

    Pu, Jiantao; Zheng, Bin; Park, Sang Cheol

    2009-02-01

    In this study we describe a visualization system of pulmonary fissures depicted on CT images. The purpose is to provide clinicians with an intuitive perception of a patient's lung anatomy through an interactive examination of fissures, enhancing their understanding and accurate diagnosis of lung diseases. This system consists of four key components: (1) region-of-interest segmentation; (2) three-dimensional surface modeling; (3) fissure type classification; and (4) an interactive user interface, by which the extracted fissures are displayed flexibly in different space domains including image space, geometric space, and mixed space using simple toggling "on" and "off" operations. In this system, the different visualization modes allow users not only to examine the fissures themselves but also to analyze the relationship between fissures and their surrounding structures. In addition, the users can adjust thresholds interactively to visualize the fissure surface under different scanning and processing conditions. Such a visualization tool is expected to facilitate investigation of structures near the fissures and provide an efficient "visual aid" for other applications such as treatment planning and assessment of therapeutic efficacy as well as education of medical professionals.

  2. High-Temperature Hydrothermal Vent Field of Kolumbo Submarine Volcano, Aegean Sea: Site of Active Kuroko-Type Mineralization

    NASA Astrophysics Data System (ADS)

    Sigurdsson, H.; Carey, S.; Alexandri, M.; Vougioukalakis, G.; Croff, K.; Roman, C.; Sakellariou, D.; Anagnostou, C.; Rousakis, G.; Ioakim, C.; Gogou, A.; Ballas, D.; Misaridis, T.; Nomikou, P.

    2006-12-01

    Kolumbo submarine volcano is located 7 km north-east of the island of Santorini in the Hellenic arc (Greece), and comprises one of about twenty submarine cones in a NE-trending rift zone. Kolumbo erupted explosively in 1649-50AD, causing 70 fatalities on Santorini. Kolumbo's crater is 1700 m in diameter, with a crater rim at 10 m below sea level and crater floor at depth of 505 m. Recent marine geological investigations, using ROVs, reveal a very active high-temperature hydrothermal vent field in the northeastern part of the Kolumbo crater floor, about 25,000 m2. Vent chimneys up to 4 m high are vigorously emitting colorless gas plumes up to 10 m high in the water column. Temperatures up to 220oC are recorded in vent fluids. Some vents are in crater- like depressions, containing debris from collapsed extinct chimneys. The entire crater floor of Kolumbo is mantled by a reddish-orange bacterial mat, and bacterial filaments of a variety of colors cling to chimneys in dense clusters. Glassy tunicates and anemones are common in lower-temperature environments on the crater floor. Most chimneys show a high porosity, with a central conduit surrounded by an open and very permeable framework of sulfides and sulfates, aiding fluid flow through the chimney walls. In the sulfate-rich samples, blades of euhedral barite and anhydrite crystals coat the outside of the chimney wall, and layers of barite alternate with sulfide in the interior. The dominant sulfides are pyrite, sphalerite, wurtzite, marcasite and galena. Crusts on extinct and lower-temperature chimneys are composed of amorphous silica, goethite and halite. Sulfur isotope composition of sulfates is virtually at sea water values, whereas the sulfides are more depleted. Elevated levels of copper, gold and silver are observed in bulk composition of chimney samples. Both the structural setting, character of the vent field and sulfide/sulfate mineralogy and geochemistry indicate on-going Kuroko-type mineralization in the

  3. Video monitoring analysis of the dynamics at fissure eruptions

    NASA Astrophysics Data System (ADS)

    Witt, Tanja; Walter, Thomas R.

    2016-04-01

    At basaltic eruption often lava fountains occur. The fountains mainly develop at erupting fissures, underlain by a magma-filled dike transporting the magma horizontally and vertically. Understanding of the dynamics of the deep dike and fracture mechanisms are mainly based on geophysical data as well as observations from seismic or geodetic networks. At the surface, however, new methods are needed to allow detailed interpretation on the eruption velocities, interactions between vents and complexities in the magma paths. With video cameras we collected imaging data from different erupting fissures. We find that lava fountaining is often correlated at distinct vents. From the frames of the videos we calculated the height and velocities of fountains as a function of time. Lava fountains often show a pulsating regime, that may change over time. Comparing the fountain height as a function of time of different vents by an time-dependent cross-correlation, we find a time lag between the pulses at adjacent vents. From this we derive an apparent velocity of temporal separation between vents, associated with the fountaining activity based on the calculated time lag and the vent distances. Although the correlation system can change episodically and sporadically, both the frequency of the fountains and eruption and the rest time between single fountains remain remarkably similar for adjacent lava fountains imply a controlling process in the magma feeder system itself. We present and compare our method for the Kamoamoa eruption 2011 (Hawaii) and the Holuhraun eruption 2014/2015 (Iceland). Both sites show a significant time shift between the single pulses of adjacent vents. We compare our velocities determined by this time shift to the assumed magma flow velocity in the dike as determined by independent models. Therefore we conjecture that the time shift of venting activity may allow to estimate the dynamics of magma and fluid migration at depth, as well as to identify the

  4. New volcanogenic-eruptive genetic type of diamond occurrence (based on studying the 2012-2013 Fissure Tolbachik Eruption in Kamchatka)

    NASA Astrophysics Data System (ADS)

    Karpov, Gennady; Anikin, Leonid; Filatov, Stanislav; Silaev, Valery; Petrovsky, Vitaly; Zolotarev, Andrey; Dunin-Barkovsky, Romuald; Volynets, Anna

    2014-05-01

    During the 2012-2013 Fissure Tolbachik eruption, diamonds were found both in fresh pyroclastics and in the effusive lava pores. Lavas are aphyric and subaphyric porous aluminous basaltic trachyandesites with rare megacrysts and subphenocrysts of plagioclase, olivine and pyroxene. Groundmass is hyalopilitic, pilotaxitic, occasionally hyaline, with abundant plagioclase microlites. So far, over 750 diamond grains have been found sized mostly 100-500 mkm. Generally, grains are well formed isometric, plane-faced and sharp-edged monocrystals of cubic-octahedral habit and green color, rarer colorless. Faces of rhombic-dodecahedron, tetragonal-trisoctahedron and trigonal-trisoctahedron also occur. Crystal cubic faces host pits of diffusive depletion, and pits with induction surfaces formed after the breakoff of syngenetic inclusions. Octahedral faces often show pyramidal etching pits formed at the dislocation outcrops. Pits contain coatings whose composition includes Fe, Mg, Ca, Si, and Cu-Sn (Zn) alloy films. Diamond X-ray diffraction data (Bruker APEX DUO, STOE IPDS II, MoKα-radiation, 788 reflections) show space group Fd-3m, cubic unit cell parameter a = 3.574(3) A and major reflections (111), (220), (311) etc. at Gandolfi pattern. Raman spectra with red beam reveal only one strong line at 1332 cm-1 typical for diamonds. Spectra excited by the 785 nm beam reveal a wide line with the peak at 1370 cm-1, whose intensity oscillates from 1% to 70% of the diamond line intensity at 1332 cm-1. Infrared absorption spectra reflect two lines with peaks at 1345 and 1130 cm-1, corresponding to structural C-defects (isolated N atoms). Partially, these defects occur in the positive charge state - N+. Structural nitrogen concentration in the form of C-defects varies from 150 to 500 ppm, while that in the form of N+ - from 10 to 30 ppm. Lines of infrared absorption on A and B1 nitrogen defects, as well as those on hydrogen defects typical for most natural diamonds, are not detected for

  5. The pattern of circumferential and radial eruptive fissures on the volcanoes of Fernandina and Isabela islands, Galapagos

    USGS Publications Warehouse

    Chadwick, W.W.; Howard, K.A.

    1991-01-01

    Maps of the eruptive vents on the active shield volcanoes of Fernandina and Isabela islands, Galapagos, made from aerial photographs, display a distinctive pattern that consists of circumferential eruptive fissures around the summit calderas and radial fissures lower on the flanks. On some volcano flanks either circumferential or radial eruptions have been dominant in recent time. The location of circumferential vents outside the calderas is independent of caldera-related normal faults. The eruptive fissures are the surface expression of dike emplacement, and the dike orientations are interpreted to be controlled by the state of stress in the volcano. Very few subaerial volcanoes display a pattern of fissures similar to that of the Galapagos volcanoes. Some seamounts and shield volcanoes on Mars morphologically resemble the Galapagos volcanoes, but more specific evidence is needed to determine if they also share common structure and eruptive style. ?? 1991 Springer-Verlag.

  6. Influence of Geologic Setting on the Morphology, Mineralogy, and Geochemistry of Vent Deposits Along the Eastern Lau Spreading Center and Valu Fa Ridge

    NASA Astrophysics Data System (ADS)

    Tivey, M. K.; Evans, G. N.; Ferrini, V. L.

    2014-12-01

    Establishment of links between lithology, vent fluid chemistry, and vent deposit characteristics along the Eastern Lau Spreading Center (ELSC) and Valu Fa Ridge (VFR) was made possible using deep submergence vehicles and technology. ROV Jason was used to collect ultrahigh-resolution (submeter) bathymetric data sufficient to quantify characteristics of volcanic, tectonic and hydrothermal features; differences within vent fields from north to south include a change from low-relief volcanic domes cut by faults and fissures to higher aspect ratio volcanic domes dominated by aa-type lava morphologies (Ferrini et al., G-cubed, 2008). Highest temperature fluids are associated with crosscutting faults at all but Mariner vent field where faults are not observed. The detailed maps were used to target areas within vent fields for observations and sampling. Vent deposit morphologies are similar at the northernmost vent fields (Kilo Moana, TowCam, Tahi Moana), with black smokers and diffusers present on branched edifices. Vent deposits at the more southerly ABE, Tui Malila and Mariner vent fields vary in morphology, despite similar substrate lithology. Examples include abundant flanges at ABE and Tui Malila and ~20m-tall spires and squat barite-rich edifices at Mariner. Geochemical analyses and petrographic observations document the influence of lithology, fluid temperature, pH, and extents of seawater mixing on deposit formation. Concentrations of As, which increase from north to south, reflect lithologic control. Sb, Pb, and Ba concentrations also reflect lithologic control, but are affected as well by low pH and/or extents of seawater mixing. The significant differences in Mariner deposits reflect formation from very high temperature, low pH (<3 vs >4) fluids that keep Zn in solution, combined with local subsurface mixing. Overall, results document the influence of the Tonga Subduction Zone on vent deposits through its affects on lithology and vent fluid composition.

  7. Direct Monte Carlo Simulations of Gas Flow from Enceladus’ Nozzle-like Vents

    NASA Astrophysics Data System (ADS)

    Tucker, Orenthal; Combi, M. R.; Tenishev, V.

    2013-10-01

    Collective observations by the Cassini spacecraft indicate that the gas plumes emanating from Enceladus’ south pole contain micrometer sized ice grains that travel at speeds 50-80% lower than the bulk gas speed (Kempf et al., 2008, Hedman et al., 2009, Teolis et al., 2010). Previous studies indicate the difference in velocity originates below the surface, and the gas flow to the surface occurs supersonically suggestive of nozzle like vents (Schmidt et al., 2008, Hansen et al., 2011). Here we use a 2D Direct Monte Carlo Simulation (DSMC) technique (Bird, 1994) to model gas flow and grain acceleration in nozzle like fissures for Enceladus’ vent geometries. First, we use the DSMC technique to model the transition of the gas flow from inside the highly collisional vent to a couple of meters above the surface where the gas flow becomes essentially collisionless. Then the DSMC results for gas density, temperature and velocity are used with an equation of motion for the drag force on a grain entrenched in a gas. The flow is tracked in both the vertical direction from the vent opening, and the radial direction from the vent axis. It is impossible to consider every type of vent geometry, but using Cassini data for grain sizes and velocities within the plumes we consider a few vent geometries of different width, length, and opening angle with respect to the surface. The Enceladus vents are not likely to be axially symmetric, but the simulations provide insight into possible vent geometries, and the effect of the vent wall geometry on gas flow and grain acceleration for suggested plume water production rates (0.5 - 1×1028 s-1) inferred using Cassini data (Tenishev et al., 2010). We obtain density and velocity distributions at the vent exit for the gas and grains that can serve as parameters for plume models and be used as comparisons for interpretation of various Cassini measurements. Kempf, S., et al., 2008, Icarus 193, 2. Hedman, M.M., et al., 2009, AJ 693. Teolis, B

  8. Identification of pulmonary fissures using a piecewise plane fitting algorithm.

    PubMed

    Gu, Suicheng; Wilson, David; Wang, Zhimin; Bigbee, William L; Siegfried, Jill; Gur, David; Pu, Jiantao

    2012-10-01

    We describe an automated computerized scheme to identify pulmonary fissures depicted in chest computed tomography (CT) examinations from a novel perspective. Whereas CT images can be regarded as a cloud of points, the underlying idea is to search for surface-like structures in the three-dimensional (3D) Euclidean space by using an efficient plane fitting algorithm. The proposed plane fitting operation is performed in a number of small spherical lung sub-volumes to detect small planar patches. Using a simple clustering criterion based on their spatial coherence and surface area, the identified planar patches, assumed to represent fissures, are classified into different types of fissures, namely left oblique, right oblique and right horizontal fissures. The performance of the developed scheme was assessed by comparing with a manually created "reference standard" and the results obtained by a previously developed approach on a dataset of 30 lung CT examinations. The experiments show that the average discrepancy is around 1.0mm in comparison with the reference standard, while the corresponding maximum discrepancy is 20.5mm. In addition, 94% of the fissure voxels identified by the computerized scheme are within 3mm of the fissures in the reference standard. As compared to a previously developed approach, we also found that the newly developed scheme had a smaller discrepancy with the standard reference. In efficiency, it takes approximately 8 min to identify the fissures in a chest CT examination on a typical PC. The developed scheme demonstrates a reasonable performance in terms of accuracy, robustness, and computational efficiency.

  9. Vented Capacitor

    DOEpatents

    Brubaker, Michael Allen; Hosking, Terry Alan

    2006-04-11

    A technique of increasing the corona inception voltage (CIV), and thereby increasing the operating voltage, of film/foil capacitors is described. Intentional venting of the capacitor encapsulation improves the corona inception voltage by allowing internal voids to equilibrate with the ambient environment.

  10. Research of features related to land subsidence and ground fissure disasters in the Beijing Plain

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Luo, Y.; Liu, M.; Wang, R.; Wang, H.

    2015-11-01

    This study overviews the development history, current situation, impact, and hazards of land subsidence and ground fissure disasters in the Beijing Plain (BP) and focuses on the disaster distribution and features of disaster-causing mechanisms. Currently, the BP is still in a rapid developmental stage of land subsidence. The development and distribution of land subsidence are affected by various factors including the thickness of Quaternary compressible clay, groundwater overexploitation, and the rapid development of urban construction. The causes of ground fissures in the BP are complex and diverse, with evidence of structure fissures, non-structure fissures, and mixed genesis fissures. Investigations of the Gaoliying ground fissure have shown that this fissure has evidence of fracture activity, with vertical deformation that is more significant than horizontal deformation. Furthermore, this ground fissure has characteristics of inter-annual periodicity and annual jumping. The land subsidence and ground fissures are all under structural control and impact each other, and more severe hazards may be induced under the superimposition of these two types of disasters. Effective measures and suggestions for disaster prevention and control are recommended on the basis of this study.

  11. An opening magmatic fissure: structural pattern of its termination

    NASA Astrophysics Data System (ADS)

    Zelenin, Egor A.; Kozhurin, Andrey I.; Pinegina, Tatiana K.; Mikhaylyukova, Polina G.

    2014-05-01

    Volcanic zones of Kamchatka bear two types of active faults and fractures. Faults of the first type are tectonic, so they are long-living with net offset growing with time by repeating movement. Faults of the second type could be termed volcano-tectonic as they couple with or are caused by eruptions and thus move just once. Authors have explored and described a NE-SW-striking fissure on the SW side of Gorely plateau in the South Kamchatka volcanic zone, which conducted magma 200 years ago (Selyangin, Ponomareva, 1999). The fissure depression is filled with basaltic-andesite lava. The 900 meters long southern terminus of the fissure is situated on the hill slope and therefore not overlapped with lava. The fissure ending is an asymmetric graben, deeper at its west side, up to 300 m wide and bounded by two nearly parallel normal faults. The graben floor is gradually deepening to the north, away from the terminus, down to 9-10 m. Bounding faults are perfectly expressed in topography, thus providing a rare opportunity for determination of fissure parameters. Both faults dip at 80-85°, that gives approximately up to 3 m of perpendicular extension and the same thickness of the dyke beneath. Vertical movements on the western and eastern bounding faults were accompanied by horizontal components, left-lateral and right-lateral, respectively. There are also several transverse north-facing scarps breaking the graben floor and not extending beyond its limits. The observed deformations altogether suggests simultaneous sinking of the graben floor and northward compensating movement of masses into the graben. Tectonic landforms we studied illustrate how strain could be compensated at the end of an opening fissure and provide some insight into similar settings at a regional and even global scale.

  12. Volcano Vents

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 5 May 2003

    This low-relief shield volcano imaged with the THEMIS visible camera has two large vents which have erupted several individual lava flows. The positions of the origins of many of the flows indicate that it is probable that the vents are secondary structures that formed only after the shield was built up by eruptions from a central caldera.

    Image information: VIS instrument. Latitude 17.6, Longitude 243.6 East (116.4 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  13. Hawaiian fissure fountains 1: decoding deposits-episode 1 of the 1969-1974 Mauna Ulu eruption

    USGS Publications Warehouse

    Parcheta, C.E.; Houghton, B.F.; Swanson, D.A.

    2012-01-01

    Deposits from episode 1 of the 1969–1974 Mauna Ulu eruption of Kīlauea provide an exceptional opportunity to study processes of low intensity Hawaiian fissure fountains. Episode 1 lava flows passed through dense forest that had little impact on flow dynamics; in contrast, the pattern of spatter preservation was strongly influenced by the forest (through the formation of tree molds) and the preexisting topography. A low, near-continuous spatter rampart is present upwind and upslope, on the north side of the fissure. Most of the pyroclastic products, however, fell downwind to the south of the fissure, but little was preserved due to two processes: (1) incorporation of proximal spatter in rheomorphic lava flows 10–20 m from the vents, and (2) the downslope transport of cooler spatter falling on top of these flows beyond 20 m from vent. The lava flow field itself shows a complex history. Initially, discharge from the fissure exceeded the transport capacity of the southern drainage pathways, and lava ponded dynamically to a maximum height of 4 m for 40–120 min, until fountains began to decline. During declining discharge, lava flowed both southward away from the fissure and increasingly back into the vents. There is a clear “lava-shed” or delineation between where lava drained northwards back into the fissure, and where it continued flowing to the south. The 1969 deposits suggest that care is needed when products of less well-documented eruptions are analyzed, as postdepositional transport of spatter may preclude the formation of classic paired (symmetrical) ramparts.

  14. Microbial isotopic signatures in calcareous tufa from Punta Mita coastal vents, Mexico

    NASA Astrophysics Data System (ADS)

    Canet, C.; Prol-Ledesma, R. M.; Melgarejo, J. C.; Reyes, A.

    2002-12-01

    Numerous small calcareous mounds accompanied by Ba, Hg and Tl mineralization occur in shallow submarine hydrothermal manifestations on the sea bottom, at 10 m depth, in Punta Mita (Western coast of Mexico). The formation of calcite mounds in these coastal vents provides an uncommon example of calcareous tufa deposits in a submarine hydrothermal environment. The hydrothermal activity consists in water and gas (essentially nitrogen and methane) venting at 85°C, through a 100 m fissure hosted in basaltic rocks and partially covered by unconsolidated sediments. The mounds consist of travertine-like metre-sized calcite aggregates that develop around the main submarine hot springs. Barite, sulphides (mostly pyrite and cinnabar) and phosphates (carbonate-hydroxylapatite) are also present in these mounds. Two main calcite types are texturally distinguished: firstly an earlier radial-fibrous generation, and a later fine-grained calcite generation that cements the detrital grains and fills the pore spaces. Stable isotope analyses were performed in calcite from these mounds. The δ13C measured values show a strong depletion in 13C, with values as low as -39.2 per mil (PDB). These values agree with a microbially mediated calcite mineralization process, by means of bacterial oxidation of vent derived methane. In contrast to most known cases of microbial methane oxidation, in Punta Mita this process took place under hydrothermal conditions.

  15. Geometry of the September 1971 eruptive fissure at Kilauea volcano, Hawaii

    USGS Publications Warehouse

    Dvorak, J.J.

    1990-01-01

    A three-dimensional model has been used to estimate the location and dimensions of the eruptive fissure for the 24-29 September 1971 eruption along the southwest rift zone of Kilauea volcano, Hawaii. The model is an inclined rectangular sheet embedded in an elastic half-space with constant displacement on the plane of the sheet. The set of "best" model parameters suggests that the sheet is vertical, extends from a depth of about 2 km to the surface, and has a length of about 14 km. Because this sheet intersects the surface where eruptive vents and extensive ground cracking formed during the eruption, this sheet probably represents the conduit for erupted lava. The amount of displacement perpendicular to the sheet is about 1.9 m, in the middle range of values measured for the amount of opening across the September 1971 eruptive fissure. The thickness of the eruptive fissure associated with the January 1983 east rift zone eruption was determined in an earlier paper to be 3.6 m, about twice the thickness determined here for the September 1971 eruption. Because the lengths (12 km for 1983 and 14 km for 1971) and heights (about 2 km) of the sheet models derived for the January 1983 and September 1971 rift zone eruptions are nearly identical, the greater thickness for the January 1983 eruptive fissure implies that the magma pressure was about a factor of two greater to form the January 1983 eruptive fissure. Because the September 1971 and January 1983 eruptive fissures extent to depths of only a few kilometers, the region of greatest compressive stress produced along the volcano's flank by either of these eruptive fissures would also be within a few kilometers of the surface. Previous work has shown that rift eruptions and intrusions contribute to the buildup of compressive stress along Kilauea's south flank and that this buildup is released by increased seismicity along the south flank. Because south flank earthquakes occur at significantly greater depths, i.e., from 5

  16. A robotic approach to mapping post-eruptive volcanic fissure conduits

    NASA Astrophysics Data System (ADS)

    Parcheta, Carolyn E.; Pavlov, Catherine A.; Wiltsie, Nicholas; Carpenter, Kalind C.; Nash, Jeremy; Parness, Aaron; Mitchell, Karl L.

    2016-06-01

    VolcanoBot was developed to map volcanic vents and their underlying conduit systems, which are rarely preserved and generally inaccessible to human exploration. It uses a PrimeSense Carmine 1.09 sensor for mapping and carries an IR temperature sensor, analog distance sensor, and an inertial measurement unit (IMU) inside a protective shell. The first field test succeeded in collecting valuable scientific data but revealed several needed improvements, including more rugged cable connections and mechanical couplers, increased ground clearance, and higher-torque motors for uphill mobility. The second field test significantly improved on all of these aspects but it traded electrical ruggedness for reduced data collection speed. Data collected by the VolcanoBots, while intermittent, yield the first insights into the cm-scale geometry of volcanic fissures at depths of up to 25 m. VolcanoBot was deployed at the 1969 Mauna Ulu fissure system on Kīlauea volcano in Hawai'i. It collected first-of-its-kind data from inside the fissure system. We hypothesized that 1) fissure sinuosity should decrease with depth, 2) irregularity should be persistent with depth, 3) any blockages in the conduit should occur at the narrowest points, and 4) the fissure should narrow with depth until it is too narrow for VolcanoBot to pass or is plugged with solidified lava. Our field campaigns did not span enough lateral or vertical area to test sinuosity. The preliminary data indicate that 1) there were many irregularities along fissures at depth, 2) blockages occurred, but not at obviously narrow locations, and 3) the conduit width remained a consistent 0.4-0.5 m for most of the upper 10 m that we analyzed.

  17. 46 CFR 38.20-1 - Venting-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Vents and headers shall be so installed as to prevent excessive stresses on safety relief valve... entrance of rain or snow. (g) No valve of any type shall be fitted in the vent pipe between the...

  18. [Anal fissure--a new therapy concept].

    PubMed

    Hetzer, F H; Baumann, M; Röthlin, M

    2000-08-24

    The anal fissure is one of the most frequent causes for anal pain. Conservative treatment usually consists of laxatives, local anesthetics and nitroglycerin cream. These therapies have a high recurrency rate. Surgical interventions, i.e. manual dilatation and sphincterotomy are fraught with the danger of fecal incontinence. The completely reversible effect of botulinum toxin injection opens new possibilities in the treatment of anal fissures. Its use is discussed as part of a 3-stage therapeutic regimen.

  19. Gas venting system

    DOEpatents

    Khan, Amjad; Dreier, Ken Wayne; Moulthrop, Lawrence Clinton; White, Erik James

    2010-06-29

    A system to vent a moist gas stream is disclosed. The system includes an enclosure and an electrochemical cell disposed within the enclosure, the electrochemical cell productive of the moist gas stream. A first vent is in fluid communication with the electrochemical cell for venting the moist gas stream to an exterior of the enclosure, and a second vent is in fluid communication with an interior of the enclosure and in thermal communication with the first vent for discharging heated air to the exterior of the enclosure. At least a portion of the discharging heated air is for preventing freezing of the moist gas stream within the first vent.

  20. The Fissure Tolbachik Basalt Eruption, Kamchatka (2012-2013): main results of its studying

    NASA Astrophysics Data System (ADS)

    Muravyev, Y. D.; Gordeev, E.; Droznin, V. A.; Volynets, A. O.

    2013-12-01

    There is a large volcanic center in the south part of the Klyuchevskaya group of volcanoes, for which fissure eruptions of mafic lavas are typical in historic times. The latest large effusion of lavas in this zone occurred over the period 1975-1976 and was called the Great Tolbachik fissure eruption (GTFE 1975-76). After 37 years of rest, in the evening of November 27, 2012 liquid basalts star ted to effuse extensively to the south of Plosky Tolbachik Volcano. One day prior to the eruption, a swarm of ear thquakes was recorded beneath the volcano. Seismic data showed that the fissure opened at 17h45m local time at an altitude of about 2.5 km on the souther n flank of Plosky Tolbachik. The fissure stretched 6 km from nor th to south. Local residents repor ted three areas of eruptions late at night. The eruption was obviously explosive in the upper part of the fissure. At this stage the fissure produced the most powerful ash emissions resulting in ash deposits as far as several tens of kilometers from the volcano. In its lower part the fissure star ted to produce extremely fluid basaltic lava. A small lava flow from the central area of eruption traveled to the west and descended 9 km along the valley of Vodopadny creek to a height of 650 m a.s.l. and destroyed Vodopadnaya base camp, which had been built during the 1975-1976 Great Tolbachik fissure eruption. By November 30, the movement of Vodopadny lava flow had ceased. The main lava flow resulted from the central part of the fissure. Gradually, the main eruptive center with up to three vents was formed above the upper fissure. The vents activity varies in time. By mid January 2013 a crater with a lava lake had been formed above the upper fissure. The crater is continuously fountaining hot material. Over the period of two months the erupted lava had covered an area of 30 km2. New portions of lava are coming to the surface along the lava channels increasing the thickness of the lava field. Sometimes lava bursts out of

  1. Overview of the precursors and dynamics of the 2012-13 basaltic fissure eruption of Tolbachik Volcano, Kamchatka, Russia

    NASA Astrophysics Data System (ADS)

    Belousov, Alexander; Belousova, Marina; Edwards, Benjamin; Volynets, Anna; Melnikov, Dmitry

    2015-12-01

    We present a broad overview of the 2012-13 flank fissure eruption of Plosky Tolbachik Volcano in the central Kamchatka Peninsula. The eruption lasted more than nine months and produced approximately 0.55 km3 DRE (volume recalculated to a density of 2.8 g/cm3) of basaltic trachyandesite magma. The 2012-13 eruption of Tolbachik is one of the most voluminous historical eruptions of mafic magma at subduction related volcanoes globally, and it is the second largest at Kamchatka. The eruption was preceded by five months of elevated seismicity and ground inflation, both of which peaked a day before the eruption commenced on 27 November 2012. The batch of high-Al magma ascended from depths of 5-10 km; its apical part contained 54-55 wt.% SiO2, and the main body 52-53 wt.% SiO2. The eruption started by the opening of a 6 km-long radial fissure on the southwestern slope of the volcano that fed multi-vent phreatomagmatic and magmatic explosive activity, as well as intensive effusion of lava with an initial discharge of > 440 m3/s. After 10 days the eruption continued only at the lower part of the fissure, where explosive and effusive activity of Hawaiian-Strombolian type occurred from a lava pond in the crater of the main growing scoria cone. The discharge rate for the nine month long, effusion-dominated eruption gradually declined from 140 to 18 m3/s and formed a compound lava field with a total area of ~ 36 km2; the effusive activity evolved from high-discharge channel-fed 'a'a lavas to dominantly low-discharge tube-fed pahoehoe lavas. On 23 August, the effusion of lava ceased and the intra-crater lava pond drained. Weak Strombolian-type explosions continued for several more days on the crater bottom until the end of the eruption around 5 September 2013. Based on a broad array of new data collected during this eruption, we develop a model for the magma storage and transport system of Plosky Tolbachik that links the storage zones of the two main genetically related magma

  2. Modeling plaque fissuring and dissection during balloon angioplasty intervention.

    PubMed

    Gasser, T Christian; Holzapfel, Gerhard A

    2007-05-01

    Balloon angioplasty intervention is traumatic to arterial tissue. Fracture mechanisms such as plaque fissuring and/or dissection occur and constitute major contributions to the lumen enlargement. However, these types of mechanically-based traumatization of arterial tissue are also contributing factors to both acute procedural complications and chronic restenosis of the treatment site. We propose physical and finite element models, which are generally useable to trace fissuring and/or dissection in atherosclerotic plaques during balloon angioplasty interventions. The arterial wall is described as an anisotropic, heterogeneous, highly deformable, nearly incompressible body, whereas tissue failure is captured by a strong discontinuity kinematics and a novel cohesive zone model. The numerical implementation is based on the partition of unity finite element method and the interface element method. The later is used to link together meshes of the different tissue components. The balloon angioplasty-based failure mechanisms are numerically studied in 3D by means of an atherosclerotic-prone human external iliac artery, with a type V lesion. Image-based 3D geometry is generated and tissue-specific material properties are considered. Numerical results show that in a primary phase the plaque fissures at both shoulders of the fibrous cap and stops at the lamina elastica interna. In a secondary phase, local dissections between the intima and the media develop at the fibrous cap location with the smallest thickness. The predicted results indicate that plaque fissuring and dissection cause localized mechanical trauma, but prevent the main portion of the stenosis from high stress, and hence from continuous tissue damage.

  3. Complete genome sequence of the aerobic, heterotroph Marinithermus hydrothermalis type strain (T1(T)) from a deep-sea hydrothermal vent chimney.

    PubMed

    Copeland, Alex; Gu, Wei; Yasawong, Montri; Lapidus, Alla; Lucas, Susan; Deshpande, Shweta; Pagani, Ioanna; Tapia, Roxanne; Cheng, Jan-Fang; Goodwin, Lynne A; Pitluck, Sam; Liolios, Konstantinos; Ivanova, Natalia; Mavromatis, Konstantinos; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam; Pan, Chongle; Brambilla, Evelyne-Marie; Rohde, Manfred; Tindall, Brian J; Sikorski, Johannes; Göker, Markus; Detter, John C; Bristow, James; Eisen, Jonathan A; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Woyke, Tanja

    2012-03-19

    Marinithermus hydrothermalis Sako et al. 2003 is the type species of the monotypic genus Marinithermus. M. hydrothermalis T1(T) was the first isolate within the phylum "Thermus-Deinococcus" to exhibit optimal growth under a salinity equivalent to that of sea water and to have an absolute requirement for NaCl for growth. M. hydrothermalis T1(T) is of interest because it may provide a new insight into the ecological significance of the aerobic, thermophilic decomposers in the circulation of organic compounds in deep-sea hydrothermal vent ecosystems. This is the first completed genome sequence of a member of the genus Marinithermus and the seventh sequence from the family Thermaceae. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 2,269,167 bp long genome with its 2,251 protein-coding and 59 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  4. Complete genome sequence of the aerobic, heterotroph Marinithermus hydrothermalis type strain (T1T) from a deep-sea hydrothermal vent chimney

    SciTech Connect

    Copeland, A; Gu, Wei; Yasawong, Montri; Lapidus, Alla L.; Lucas, Susan; Deshpande, Shweta; Pagani, Ioanna; Tapia, Roxanne; Cheng, Jan-Fang; Goodwin, Lynne A.; Pitluck, Sam; Liolios, Konstantinos; Ivanova, N; Mavromatis, K; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam L; Pan, Chongle; Brambilla, Evelyne-Marie; Rohde, Manfred; Tindall, Brian; Sikorski, Johannes; Goker, Markus; Detter, J. Chris; Bristow, James; Eisen, Jonathan; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Woyke, Tanja

    2012-01-01

    Marinithermus hydrothermalis Sako et al. 2003 is the type species of the monotypic genus Marinithermus. M. hydrothermalis T1 T was the first isolate within the phylum ThermusDeinococcus to exhibit optimal growth under a salinity equivalent to that of sea water and to have an absolute requirement for NaCl for growth. M. hydrothermalis T1 T is of interest because it may provide a new insight into the ecological significance of the aerobic, thermophilic decomposers in the circulation of organic compounds in deep-sea hydrothermal vent ecosystems. This is the first completed genome sequence of a member of the genus Marinithermus and the seventh sequence from the family Thermaceae. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 2,269,167 bp long genome with its 2,251 protein-coding and 59 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  5. Fissure distribution at Mauna Loa (Hawaii) as an example to understand shallow magma transfer at volcanoes

    NASA Astrophysics Data System (ADS)

    La Marra, Daniele; Acocella, Valerio; Trusdell, Frank

    2016-04-01

    Mauna Loa (Hawaii) is the largest active shield volcano on the Island of Hawai'i, covering more than half of it and rising to 4,169 meters above sea level. The volcano hosts the Moku'aweoweo summit caldera, from which two elongated rift zones depart: the Northeast Rift Zone (NERZ) and the Southwest Rift Zone (SWRZ). Most of Mauna Loa's eruptions begin with lava fountains from a series of fissure vents in the summit region and then often migrate to vents down either rift zone. Mauna Loa volcano shows a distinctive feature, being characterized by minor radial eruptive fissures (not related to the two main rifts) on the NW flank only. This study tries to explain such a selective distribution of vents, and thus of shallow magma transfer. To this aim, we run numerical models with different amount of opening of the two rift zones of Mauna Loa, as well as different amount of slip on its SE flank. Our results suggest that the selective occurrence of the radial fissures may be explained by the competition between two processes: a) rift intrusion (especially along the NERZ), promoting the development of radial dikes along the NW flank; b) flank slip, inhibiting the development of the radial dikes on the SE flank. The opening of the two non-parallel main rift zones of Mauna Loa promotes the local extension necessary to develop the radial dikes on the NW flank. A general model for the development of a third branch of radial rift, which may be also applied to Mt. Etna and some volcanoes on the Canary Islands, is proposed.

  6. [The treatment of chronic fissure in ano with nitrate ointment].

    PubMed

    Stassen, L P; Schouten, W R

    1999-01-01

    A chronic anal fissure may be regarded as an ischaemic ulcer. Until recently, its treatment necessitated surgical intervention to lower the tension of the internal sphincter (lateral internal sphincterotomy), or manual dilatation of the anus. A disadvantage of both methods is the risk of permanent sphincter injury resulting in reduced continence. Local application of ointment containing nitroglycerin (glyceryltrinitrate) or isosorbide dinitrate reduces the pressure at rest in the anal canal and increases the anodermal blood circulation. Both ointments in most patients lead to healing of the chronic anal fissure. Nitroglycerin ointment in a prospective, randomized trial brought about better healing than placebo treatment. The advantage of the ointment treatment, the needlessness of sphincterotomy, is particularly important in cases of existing sphincter abnormalities. It has the disadvantage that it takes longer for the fissure pain to abate. The principal side effect is headache. In over 50% of the patients the treatment has to be continued for longer than 6 weeks. Little is known as yet about the risk of recurrence. Before surgical interventions as the treatment of first choice can be definitely replaced by treatment with nitrate ointment the good results of the ointment treatment have to be confirmed. Also, more has to be found out about the risk of recurrence, the optimal duration of the treatment and the choice of the type of nitrate ointment.

  7. Identifying the best therapy for chronic anal fissure

    PubMed Central

    Madalinski, Mariusz H

    2011-01-01

    Chronic anal fissure (CAF) is a painful tear or crack which occurs in the anoderm. The optimal algorithm of therapy for CAF is still debated. Lateral internal sphincterotomy (LIS) is a surgical treatment, considered as the ‘gold standard’ therapy for CAF. It relieves CAF symptoms with a high rate of healing. Chemical sphincterotomy (CS) with nitrates, calcium blockers or botulinum toxin (BTX) is safe, with the rapid relief of pain, mild side-effects and no risk of surgery or anesthesia, but is a statistically less effective therapy for CAF than LIS. This article considers if aggressive treatment should only be offered to patients who fail pharmacological sphincterotomy. Aspects of anal fissure etiology, epidemiology and pathophysiology are considered with their meaning for further management of CAF. A molecular model of chemical interdependence significant for the chemistry of CAF healing is examined. Its application may influence the development of optimal therapy for CAF. BTX is currently considered the most effective type of CS and discussion in this article scrutinizes this method specifically. Although the effectiveness of BTX vs. LIS has been discussed, the essential focus of the article concerns identifying the best therapy application for anal fissure. Elements are presented which may help us to predict CAF healing. They provide rationale for the expansion of the CAF therapy algorithm. Ethical and economic factors are also considered in brief. As long as the patient is willing to accept the potential risk of fecal incontinence, we have grounds for the ‘gold standard’ (LIS) as the first-line treatment for CAF. The author concludes that, when the diagnosis of the anal fissure is established, CS should be considered for both ethical and economic reasons. He is convinced that a greater understanding and recognition of benign anal disorders by the GP and a proactive involvement at the point of initial diagnosis would facilitate the consideration of CS at

  8. Testing Geyser Models using Down-vent Data

    NASA Astrophysics Data System (ADS)

    Wang, C.; Munoz, C.; Ingebritsen, S.; King, E.

    2013-12-01

    Geysers are often studied as an analogue to magmatic volcanoes because both involve the transfer of mass and energy that leads to eruption. Several conceptual models have been proposed to explain geyser eruption, but no definitive test has been performed largely due to scarcity of down-vent data. In this study we compare simulated time histories of pressure and temperature against published data for the Old Faithful geyser in the Yellowstone National Park and new down-vent measurements from geysers in the El Tatio geyser field of northern Chile. We test two major types of geyser models by comparing simulated and field results. In the chamber model, the geyser system is approximated as a fissure-like conduit connected to a subsurface chamber of water and steam. Heat supplied to the chamber causes water to boil and drives geyser eruptions. Here the Navier-Stokes equation is used to simulate the flow of water and steam. In the fracture-zone model, the geyser system is approximated as a saturated fracture zone of high permeability and compressibility, surrounded by rock matrix of relatively low permeability and compressibility. Heat supply from below causes pore water to boil and drives geyser eruption. Here a two-phase form of Darcy's law is assumed to describe the flow of water and steam (Ingebritsen and Rojstaczer, 1993). Both models can produce P-T time histories qualitatively similar to field results, but the simulations are sensitive to assumed parameters. Results from the chamber model are sensitive to the heat supplied to the system and to the width of the conduit, while results from the fracture-zone model are most sensitive to the permeability of the fracture zone and the adjacent wall rocks. Detailed comparison between field and simulated results, such as the phase lag between changes of pressure and temperature, may help to resolve which model might be more realistic.

  9. Robust pulmonary lobe segmentation against incomplete fissures

    NASA Astrophysics Data System (ADS)

    Gu, Suicheng; Zheng, Qingfeng; Siegfried, Jill; Pu, Jiantao

    2012-03-01

    As important anatomical landmarks of the human lung, accurate lobe segmentation may be useful for characterizing specific lung diseases (e.g., inflammatory, granulomatous, and neoplastic diseases). A number of investigations showed that pulmonary fissures were often incomplete in image depiction, thereby leading to the computerized identification of individual lobes a challenging task. Our purpose is to develop a fully automated algorithm for accurate identification of individual lobes regardless of the integrity of pulmonary fissures. The underlying idea of the developed lobe segmentation scheme is to use piecewise planes to approximate the detected fissures. After a rotation and a global smoothing, a number of small planes were fitted using local fissures points. The local surfaces are finally combined for lobe segmentation using a quadratic B-spline weighting strategy to assure that the segmentation is smooth. The performance of the developed scheme was assessed by comparing with a manually created reference standard on a dataset of 30 lung CT examinations. These examinations covered a number of lung diseases and were selected from a large chronic obstructive pulmonary disease (COPD) dataset. The results indicate that our scheme of lobe segmentation is efficient and accurate against incomplete fissures.

  10. Earth fissures and localized differential subsidence.

    USGS Publications Warehouse

    Holzer, Thomas L.; Pampeyan, Earl H.

    1981-01-01

    Long linear tension cracks associated with declining groundwater levels at four sites in subsiding areas in south-central Arizona, Fremont Valley, California, and Las Vegas Valley, Nevada, occur near points of maximum convex-upward curvature in subsidence profiles oriented perpendicular to the cracks. Profiles are based on repeated precise vertical control surveys of lines of closely spaced bench marks. Association of these fissures with zones of localized differential subsidence indicates that linear earth fissures are caused by horizontal tensile strains probably resulting from localized differential compaction. Horizontal tensile strains across the fissures at the point of maximum convex-upward curvature, ranging from approximately 100 to 700 microstrains (0.01 to 0.07% per year), were indicated based on measurements with a tape or electronic distance meter.

  11. Hydrothermal vents of Yellowstone Lake, Yellowstone National Park, Wyoming

    SciTech Connect

    Kaplinski, M.A.; Morgan, P. . Geology Dept.)

    1993-04-01

    Hydrothermal vent systems within Yellowstone Lake are located within the Yellowstone caldera in the northeastern and West Thumb sections of the lake. The vent systems lie within areas of extremely high geothermal gradients (< 1,000 C/km) in the lake sediments and occur as clusters of individual vents that expel both hydrothermal fluids and gas. Regions surrounding the vents are colonized by unique, chemotropic biologic communities and suggest that hydrothermal input plays an important role in the nutrient dynamics of the lake's ecosystem. The main concentration of hydrothermal activity occurs in the northeast region of the main lake body in a number of locations including: (1) along the shoreline from the southern edge of Sedge Bay to the inlet of Pelican Creek; (2) the central portion of the partially submerged Mary Bay phreatic explosion crater, within deep (30--50 m) fissures; (3) along the top of a 3 km long, steep-sided ridge that extends from the southern border of Mary Bay, south-southeast into the main lake basin; and (4) east of Stevenson Island along the lower portion of the slope (50--107 m) into the lake basin, within an anastomosing series of north to northwest trending, narrow troughs or fissures. Hydrothermal vents were also located within, and surrounding the West Thumb of Yellowstone Lake, with the main concentration occurring the offshore of the West Thumb and Potts Geyser Basin. Hydrothermal vents in Yellowstone Lake occur along fractures that have penetrated the lake sediments or along the tops of ridges and near shore areas. Underneath the lake, rising hydrothermal fluids encounter a semi-permeable cap of lake sediments. Upwardly convecting hydrothermal fluid flow may be diverted by the impermeable lake sediments along the buried, pre-existing topography. These fluids may continue to rise along topography until fractures are encountered, or the lake sediment cover is thinned sufficiently to allow egress of the fluids.

  12. Effect of surface fissure on apparent resistivity measurements

    NASA Astrophysics Data System (ADS)

    Sailhac, P.; Gance, J.; Malet, J.

    2013-12-01

    Fissures are features of interest, prone to create preferential flow path, modifying locally the soil hydrogeological behavior. Electrical Resistivity Tomography (ERT) is a suitable tool to monitor such preferential flow path. However, this technique is not efficient in the presence of surface fissure, due to a bad resistivity recovering around the fissure vicinity during the inversion process. Therefore, we propose a description of fissure effect on raw apparent resistivity on three resistivity arrays. The purposes of the study are multiple. First, we aim at making ERT users aware of surface fissure effect, and propose a first help to interpret basically resistivity pseudo sections. Second, we propose to ERT users to automatically conduct a surface fissure survey on the studied profile, in order to consider each fissure in a forward DC model and to suppress their effect. Finally, this study is only a first step toward 2D fissure shape inversion, and time-lapse monitoring of fissure drying and filling. In this study, we create a fissure model based on different geomorphological descriptors. After describing the FEM-DC forward modeling strategy, we investigate the fissure effect on pseudo section of apparent resistivity for a Wenner-Schlumberger (WS), a dipole-dipole (DD) and a gradient (GRAD) array. We determine a fissure detectability threshold for each array and perform a sensitivity analysis on the different fissure parameters (position, width, depth, dip angles...). The crack filling or drying effect is also investigated. The possibility to remove fissure effect and to propose a first interpretation of time-lapse data is illustrated on real data. This study show again the higher sensitivity of the DD array compared to the GRAD and WS arrays. Not only the maximal amplitude in the pseudo section is higher for the DD array, but also the anomaly pattern created by the fissure is much larger for this acquisition geometry. The minimal depth detectable for the DD

  13. Battery venting system and method

    DOEpatents

    Casale, Thomas J.; Ching, Larry K. W.; Baer, Jose T.; Swan, David H.

    1999-01-05

    Disclosed herein is a venting mechanism for a battery. The venting mechanism includes a battery vent structure which is located on the battery cover and may be integrally formed therewith. The venting mechanism includes an opening extending through the battery cover such that the opening communicates with a plurality of battery cells located within the battery case. The venting mechanism also includes a vent manifold which attaches to the battery vent structure. The vent manifold includes a first opening which communicates with the battery vent structure opening and second and third openings which allow the vent manifold to be connected to two separate conduits. In this manner, a plurality of batteries may be interconnected for venting purposes, thus eliminating the need to provide separate vent lines for each battery. The vent manifold may be attached to the battery vent structure by a spin-welding technique. To facilitate this technique, the vent manifold may be provided with a flange portion which fits into a corresponding groove portion on the battery vent structure. The vent manifold includes an internal chamber which is large enough to completely house a conventional battery flame arrester and overpressure safety valve. In this manner, the vent manifold, when installed, lessens the likelihood of tampering with the flame arrester and safety valve.

  14. Battery Vent Mechanism And Method

    DOEpatents

    Ching, Larry K. W.

    2000-02-15

    Disclosed herein is a venting mechanism for a battery. The venting mechanism includes a battery vent structure which is located on the battery cover and may be integrally formed therewith. The venting mechanism includes an opening extending through the battery cover such that the opening communicates with a plurality of battery cells located within the battery case. The venting mechanism also includes a vent manifold which attaches to the battery vent structure. The vent manifold includes a first opening which communicates with the battery vent structure opening and second and third openings which allow the vent manifold to be connected to two separate conduits. In this manner, a plurality of batteries may be interconnected for venting purposes, thus eliminating the need to provide separate vent lines for each battery. The vent manifold may be attached to the battery vent structure by a spin-welding technique. To facilitate this technique, the vent manifold may be provided with a flange portion which fits into a corresponding groove portion on the battery vent structure. The vent manifold includes an internal chamber which is large enough to completely house a conventional battery flame arrester and overpressure safety valve. In this manner, the vent manifold, when installed, lessens the likelihood of tampering with the flame arrester and safety valve.

  15. Battery venting system and method

    DOEpatents

    Casale, T.J.; Ching, L.K.W.; Baer, J.T.; Swan, D.H.

    1999-01-05

    Disclosed herein is a venting mechanism for a battery. The venting mechanism includes a battery vent structure which is located on the battery cover and may be integrally formed therewith. The venting mechanism includes an opening extending through the battery cover such that the opening communicates with a plurality of battery cells located within the battery case. The venting mechanism also includes a vent manifold which attaches to the battery vent structure. The vent manifold includes a first opening which communicates with the battery vent structure opening and second and third openings which allow the vent manifold to be connected to two separate conduits. In this manner, a plurality of batteries may be interconnected for venting purposes, thus eliminating the need to provide separate vent lines for each battery. The vent manifold may be attached to the battery vent structure by a spin-welding technique. To facilitate this technique, the vent manifold may be provided with a flange portion which fits into a corresponding groove portion on the battery vent structure. The vent manifold includes an internal chamber which is large enough to completely house a conventional battery flame arrester and overpressure safety valve. In this manner, the vent manifold, when installed, lessens the likelihood of tampering with the flame arrester and safety valve. 8 figs.

  16. Payload bay atmospheric vent airflow testing at the Vibration and Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Johnston, James D., Jr.

    1988-01-01

    Several concerns related to venting the Space Shuttle Orbiter payload bay during launch led to laboratory experiments with a flight-type vent box installed in the wall of a subsonic wind tunnel. This report describes the test setups and procedures used to acquire data for characterization of airflow through the vent box and acoustic tones radiated from the vent-box cavity. A flexible boundary-layer spoiler which reduced the vent-tone amplitude is described.

  17. Hydraulic fracturing in tight, fissured media

    SciTech Connect

    Warpinski, N.R. )

    1991-02-01

    Large volumes of natural gas are found in tight, fissured reservoirs. Hydraulic fracturing can enhance recovery, but many complications, such as pressure-sensitive or accelerated leakoff, damage, and complex fracturing, arise during treatment of such reservoirs. This paper reports that special procedures generally should be considered during breakdown and fracturing of these reservoirs. In addition, the use of alternative stimulation strategies may be beneficial.

  18. Multiple I-Type Lysozymes in the Hydrothermal Vent Mussel Bathymodiolus azoricus and Their Role in Symbiotic Plasticity.

    PubMed

    Detree, Camille; Chabenat, Apolline; Lallier, François H; Satoh, Nori; Shoguchi, Eiichi; Tanguy, Arnaud; Mary, Jean

    2016-01-01

    The aim of this study was first to identify lysozymes paralogs in the deep sea mussel Bathymodiolus azoricus then to measure their relative expression or activity in different tissue or conditions. B. azoricus is a bivalve that lives close to hydrothermal chimney in the Mid-Atlantic Ridge (MAR). They harbour in specialized gill cells two types of endosymbiont (gram-bacteria): sulphide oxidizing bacteria (SOX) and methanotrophic bacteria (MOX). This association is thought to be ruled by specific mechanism or actors of regulation to deal with the presence of symbiont but these mechanisms are still poorly understood. Here, we focused on the implication of lysozyme, a bactericidal enzyme, in this endosymbiosis. The relative expression of Ba-lysozymes paralogs and the global anti-microbial activity, were measured in natural population (Lucky Strike--1700 m, Mid-Atlantic Ridge), and in in situ experimental conditions. B. azoricus individuals were moved away from the hydrothermal fluid to induce a loss of symbiont. Then after 6 days some mussels were brought back to the mussel bed to induce a re-acquisition of symbiotic bacteria. Results show the presence of 6 paralogs in B. azoricus. In absence of symbionts, 3 paralogs are up-regulated while others are not differentially expressed. Moreover the global activity of lysozyme is increasing with the loss of symbiont. All together these results suggest that lysozyme may play a crucial role in symbiont regulation.

  19. Multiple I-Type Lysozymes in the Hydrothermal Vent Mussel Bathymodiolus azoricus and Their Role in Symbiotic Plasticity.

    PubMed

    Detree, Camille; Chabenat, Apolline; Lallier, François H; Satoh, Nori; Shoguchi, Eiichi; Tanguy, Arnaud; Mary, Jean

    2016-01-01

    The aim of this study was first to identify lysozymes paralogs in the deep sea mussel Bathymodiolus azoricus then to measure their relative expression or activity in different tissue or conditions. B. azoricus is a bivalve that lives close to hydrothermal chimney in the Mid-Atlantic Ridge (MAR). They harbour in specialized gill cells two types of endosymbiont (gram-bacteria): sulphide oxidizing bacteria (SOX) and methanotrophic bacteria (MOX). This association is thought to be ruled by specific mechanism or actors of regulation to deal with the presence of symbiont but these mechanisms are still poorly understood. Here, we focused on the implication of lysozyme, a bactericidal enzyme, in this endosymbiosis. The relative expression of Ba-lysozymes paralogs and the global anti-microbial activity, were measured in natural population (Lucky Strike--1700 m, Mid-Atlantic Ridge), and in in situ experimental conditions. B. azoricus individuals were moved away from the hydrothermal fluid to induce a loss of symbiont. Then after 6 days some mussels were brought back to the mussel bed to induce a re-acquisition of symbiotic bacteria. Results show the presence of 6 paralogs in B. azoricus. In absence of symbionts, 3 paralogs are up-regulated while others are not differentially expressed. Moreover the global activity of lysozyme is increasing with the loss of symbiont. All together these results suggest that lysozyme may play a crucial role in symbiont regulation. PMID:26882089

  20. Multiple I-Type Lysozymes in the Hydrothermal Vent Mussel Bathymodiolus azoricus and Their Role in Symbiotic Plasticity

    PubMed Central

    Detree, Camille; Chabenat, Apolline; Lallier, François H.; Satoh, Nori; Shoguchi, Eiichi; Tanguy, Arnaud; Mary, Jean

    2016-01-01

    The aim of this study was first to identify lysozymes paralogs in the deep sea mussel Bathymodiolus azoricus then to measure their relative expression or activity in different tissue or conditions. B. azoricus is a bivalve that lives close to hydrothermal chimney in the Mid-Atlantic Ridge (MAR). They harbour in specialized gill cells two types of endosymbiont (gram—bacteria): sulphide oxidizing bacteria (SOX) and methanotrophic bacteria (MOX). This association is thought to be ruled by specific mechanism or actors of regulation to deal with the presence of symbiont but these mechanisms are still poorly understood. Here, we focused on the implication of lysozyme, a bactericidal enzyme, in this endosymbiosis. The relative expression of Ba-lysozymes paralogs and the global anti-microbial activity, were measured in natural population (Lucky Strike -1700m, Mid-Atlantic Ridge), and in in situ experimental conditions. B. azoricus individuals were moved away from the hydrothermal fluid to induce a loss of symbiont. Then after 6 days some mussels were brought back to the mussel bed to induce a re-acquisition of symbiotic bacteria. Results show the presence of 6 paralogs in B. azoricus. In absence of symbionts, 3 paralogs are up-regulated while others are not differentially expressed. Moreover the global activity of lysozyme is increasing with the loss of symbiont. All together these results suggest that lysozyme may play a crucial role in symbiont regulation. PMID:26882089

  1. 24 CFR 3280.611 - Vents and venting.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... Link to an amendment published at 78 FR 73986, Dec. 9, 2013. (a) General. Each plumbing fixture trap... more than one fixture, or, (iii) Two or more vented drains when at least one is wet-vented, or 2-inch.... Each individually vented fixture with a 11/2 inch or smaller trap shall be provided with a vent...

  2. Fissural volcanism, polygenetic volcanic fields, and crustal thickness in the Payen Volcanic Complex on the central Andes foreland (Mendoza, Argentina)

    NASA Astrophysics Data System (ADS)

    Mazzarini, F.; Fornaciai, A.; Bistacchi, A.; Pasquarè, F. A.

    2008-09-01

    Shield volcanoes, caldera-bearing stratovolcanoes, and monogenetic cones compose the large fissural Payen Volcanic Complex, located in the Andes foreland between latitude 35°S and 38°S. The late Pliocene-Pleistocene and recent volcanic activity along E-W trending eruptive fissures produced basaltic lavas showing a within-plate geochemical signature. The spatial distribution of fractures and monogenetic vents is characterized by self-similar clustering with well defined power law distributions. Vents have average spacing of 1.27 km and fractal exponent D = 1.33 defined in the range 0.7-49.3 km. The fractal exponent of fractures is 1.62 in the range 1.5-48.1 km. The upper cutoffs of fractures and vent fractal distributions (about 48-49 km) scale to the crustal thickness in the area, as derived from geophysical data. This analysis determines fractured media (crust) thickness associated with basaltic retroarc eruptions. We propose that the Payen Volcanic Complex was and is still active under an E-W crustal shortening regime.

  3. Subsurface Gas Flow and Ice Grain Acceleration within Enceladus and Europa Fissures: 2D DSMC Models

    NASA Astrophysics Data System (ADS)

    Tucker, O. J.; Combi, M. R.; Tenishev, V.

    2014-12-01

    The ejection of material from geysers is a ubiquitous occurrence on outer solar system bodies. Water vapor plumes have been observed emanating from the southern hemispheres of Enceladus and Europa (Hansen et al. 2011, Roth et al. 2014), and N2plumes carrying ice and ark particles on Triton (Soderblom et al. 2009). The gas and ice grain distributions in the Enceladus plume depend on the subsurface gas properties and the geometry of the fissures e.g., (Schmidt et al. 2008, Ingersoll et al. 2010). Of course the fissures can have complex geometries due to tidal stresses, melting, freezing etc., but directly sampled and inferred gas and grain properties for the plume (source rate, bulk velocity, terminal grain velocity) can be used to provide a basis to constrain characteristic dimensions of vent width and depth. We used a 2-dimensional Direct Simulation Monte Carlo (DSMC) technique to model venting from both axi-symmetric canyons with widths ~2 km and narrow jets with widths ~15-40 m. For all of our vent geometries, considered the water vapor source rates (1027­ - 1028 s-1) and bulk gas velocities (~330 - 670 m/s) obtained at the surface were consistent with inferred values obtained by fits of the data for the plume densities (1026 - 1028 s-1, 250 - 1000 m/s) respectively. However, when using the resulting DSMC gas distribution for the canyon geometries to integrate the trajectories of ice grains we found it insufficient to accelerate submicron ice grains to Enceladus' escape speed. On the other hand, the gas distributions in the jet like vents accelerated grains > 10 μm significantly above Enceladus' escape speed. It has been suggested that micron-sized grains are ejected from the vents with speeds comparable to the Enceladus escape speed. Here we report on these results including comparisons to results obtained from 1D models as well as discuss the implications of our plume model results. We also show preliminary results for similar considerations applied to Europa

  4. [Fissures in biliary calculi. Personal contribution (author's transl)].

    PubMed

    Nano, M; Potenzoni, F; Camandona, M; Casalegno, P A

    1979-04-01

    In a series of 70 patients suffering from biliary lithiasis, the roentgenologic findings of fissures in the calculi was observed in 5 cases examined by means of cholecystography and in 7 cases who underwent cholangiocholecystography. Fissures were demonstrated 11 times in calculi after surgery. The "Mercedes-Benz" sign was never observed at the abdominal examination without contrast medium. The presence of fissures may be an additional sign in the radiologic diagnosis of biliary calculi, but its value is not determinant.

  5. [Fissures in biliary calculi. Personal contribution (author's transl)].

    PubMed

    Nano, M; Potenzoni, F; Camandona, M; Casalegno, P A

    1979-04-01

    In a series of 70 patients suffering from biliary lithiasis, the roentgenologic findings of fissures in the calculi was observed in 5 cases examined by means of cholecystography and in 7 cases who underwent cholangiocholecystography. Fissures were demonstrated 11 times in calculi after surgery. The "Mercedes-Benz" sign was never observed at the abdominal examination without contrast medium. The presence of fissures may be an additional sign in the radiologic diagnosis of biliary calculi, but its value is not determinant. PMID:550199

  6. [Test of an electronic fissure caries detector].

    PubMed

    Pieper, K; Visser, H; Hülsmann, M; Wahner, M

    1990-11-01

    The reliability of an electronic detector for caries in pits and fissures was tested by means of physical measurements, histological sections and clinical evaluation. The device measures the ohmic resistance of the tooth, technical data are given. First we compared measurements and histological sections of teeth due for extraction. The results indicated a high sensitivity of the device for caries, false positive diagnoses did not occur. Based on this, a clinical evaluation on 179 teeth was performed. Under practical conditions the sensitivity of the electronic detector (0.77) was lower than in the first part of the study; conventional diagnosis revealed more carious lesions in dentine (sensitivity: 0.82).

  7. Corrections of surface fissure effect on apparent resistivity measurements

    NASA Astrophysics Data System (ADS)

    Gance, J.; Sailhac, P.; Malet, J.-P.

    2015-02-01

    Electrical resistivity tomography (ERT) is a useful tool to detect and track water flow paths in the subsoil. However, measurements are strongly affected by subsurface heterogeneities such as fissures of different sizes and genesis (shrinking-swelling, macropores and deformation). In this work, we focus on surface fissures characterized by dimensions lower than the interelectrode spacing and correct their effect on apparent resistivity pseudo-sections by incorporating fissure geometry in the topography. We show that fissures with depths greater than 0.10 times the interelectrode spacing for a dipole-dipole array and equal to 0.16 for the gradient array and the Wenner-Schlumberger arrays create significant anomalies (greater than 5 per cent) in the pseudo-section. Surface fissure widths and dip angles have little effect with respect to the fissure depths which can increase the apparent resistivity up to 200 per cent. The clogging of the fissures with water or soil material decreases the anomaly effect linearly with the percentage of filling. The correction of apparent resistivity values is possible for relatively simple fissure geometries and only requires a manual survey of the surface fissures. It allows to improve the quality of the inverted resistivity section by mitigating the inversion artefacts and therefore a better interpretation.

  8. Are eruptions from linear fissures and caldera ring dykes more likely to produce pyroclastic flows?

    NASA Astrophysics Data System (ADS)

    Jessop, D. E.; Gilchrist, J.; Jellinek, A. M.; Roche, O.

    2016-11-01

    Turbulent volcanic jets are produced by highly-energetic explosive eruptions and may form buoyant plumes that rise many tens of kilometres into the atmosphere to form umbrella clouds or collapse to generate ground-hugging pyroclastic flows. Ash injected into the atmosphere can be transported for many hundreds of kilometres with the potential to affect climate, disrupt global air travel and cause respiratory health problems. Pyroclastic flows, by contrast, are potentially catastrophic to populations and infrastructure close to the volcano. Key to which of these two behaviours will occur is the extent to which the mechanical entrainment and mixing of ambient air into the jet by large (entraining) eddies forming the jet edge changes the density of the air-ash mixture: low entrainment rates lead to pyroclastic flows and high entrainment rates give rise to buoyant plumes. Recent experiments on particle-laden (multi-phase) volcanic jets from flared and straight-sided circular openings suggest that the likelihood for buoyant plumes will depend strongly on the shape and internal geometry of the vent region. This newly recognised sensitivity of the fate of volcanic jets to the structure of the vent is a consequence of a complex dynamic coupling between the jet and entrained solid particles, an effect that has generally been overlooked in previous studies. Building on this work, here we use an extensive series of experiments on multi-phase turbulent jets from analogue linear fissures and annular ring fractures to explore whether the restrictive vent geometry during cataclysmic caldera-forming (CCF) eruptions will ultimately lead a relatively greater frequency of pyroclastic flows than eruptions from circular vents on stratovolcanoes. Our results, understood through scaling analyses and a one-dimensional theoretical model, show that entrainment is enhanced where particle motions contribute angular momentum to entraining eddies. However, because the size of the entraining

  9. Distributed Computing for Seismic Data Retrieval using FISSURES DHI Client FMI Implimented from MatSeis 1.9

    NASA Astrophysics Data System (ADS)

    Hart, D. M.; Li, Q.; Creager, K. C.; Ning, R.; Crotwell, H. P.; Zuzlewski, S.; Hellman, S. B.; Schoch, K. S.; Laughbon, C. J.; Stromme, S. R.

    2004-12-01

    Three software development efforts have recently combined to allow a seamless method for obtaining data from the IRIS DMC over the Internet and analyzing it in MATLAB. During the past few years IRIS has constructed the initial framework and definitions for FISSURES servers and Data Handling Interface (DHI) clients. FISSURES uses the distributed computing language Common Object Request Broker Architecture (CORBA), which allows software systems to work across the Internet in a platform independent and computer-language neutral manner. Starting from the FISSURES object model three seismic services have been defined: event, network and seismogram. From these three object types a DHI client is used to access information through FISSURES services. Using the University of Washington developed FISSURES-Matlab-Interface (FMI) DHI client, all three FISSURES objects can be accessed via the Internet and downloaded into local MATLAB objects, allowing access to earthquake event catalogs, seismograms, network and instrument information. The DHI client FMI can be implemented from MatSeis. MatSeis, developed at Sandia National Laboratory, is a MATLAB based, Graphical User Interface (GUI) controlled software package with seismic data visualization, signal processing, and database importing and exporting capabilities, to list just a few. In this poster, we will discuss the seismic data retrieval currently prototyped for the IRIS DMC, as well as the planned connections to the Northern California Earthquake Data Center (NCEDC), Southern California Earthquake Data Center (SCEDC), and South Carolina Earth Physics Project (SCEPP) data center.

  10. Parachute having improved vent line stacking

    NASA Technical Reports Server (NTRS)

    Hengel, John E.

    1994-01-01

    A parachute having an improved vent line stacking wherein the parachute is provided with a canopy having a central vent opening and a vent band secured to the canopy around the periphery of the vent opening, with a plurality of vent lines each lying on a diameter of the vent opening and having its ends secured to the vent band on opposite sides of the vent opening is described. The vent lines are sewed to the vent band in an order such that the end of a first vent line is sewed to the vent band at a starting point with the end of a second vent band then being sewed to the vent band adjacent to and counterclockwise from the first band. A third vent band is sewed to the vent band adjacent to and clockwise from the first band, with a fourth vent band being sewed to the vent band adjacent to and counterclockwise from the second vent band. It can be seen that, if the vent lines are numbered in the order of being sewed to the vent band, the odd numbered vent lines will run consecutively in a clockwise direction and the even numbered lines will run consecutively in a counterclockwise direction from the starting point. With this order of assembly, each and every vent line will be separated from adjacent vent lines by no more than one vent line in the center of the vent opening where the vent lines cross.

  11. Overview of the 2012-13 basaltic fissure eruption of Tolbachik, Kamchatka, Russia

    NASA Astrophysics Data System (ADS)

    Belousov, Alexander; Belousova, Marina; Edwards, Benjamin; Volynetz, Anna; Melnikov, Dmitry; Senyukov, Sergey

    2014-05-01

    On 27 November 2012 a short-lived swarm of shallow (<10 km) earthquakes marked the onset of a new eruption from the Tolbachik volcanic complex, in east-central Kamchatka, Russia. The 3.5-km-long radial eruptive fissure opened on the south flank between 1500-2000 m a.s.l. Lava fountaining from multiple small vents ceased after several days and the eruption continued from vents at the southern end of the fissure. Almost continuous lava fountains up to 200 m high issued from a small lava lake located inside the broad, open crater of the largest cinder cone. While explosive activity was rather mild, initial discharge of lava was very high (up to 400 m3/s) and by the end of December 'a'a lava flows had travelled up to 17 km from the vent. SiO2 concentrations for the plagioclase-phyric lava were 54 wt.%, but then decreased to 52 wt.%. In January 2013 lava was transported through a system of lava tubes 1 km long and up to 5 m wide. From tube exit points it propagated in the form of channelized lava streams (velocities 1-3 m/s; discharge rates 30-50 m3/s); on lower slopes of the volcano it propagated mostly as 'a'a flows. Lava channels were frequently dammed by floating clinker and accretionary lava balls, which caused flooding of proximal areas by ropy/shelly/slabby pahoehoe lavas. Locally small volumes of lava were extruded through the upper surfaces and lateral levees of 'a'a lava to form very slowly inflating entrail pahoehoe lava lobes. Starting in mid-February the average intensity of the eruption gradually declined, with sporadic bursts in February and April. By May discharge rates of lava had decreased to approximately 15 m3/s and most of lava started to flow as entrail pahoehoe. By the beginning of June the volume of erupted products (dominantly lavas) reached 0.52km3. The effusion of lava continued until the end of August, when the lava lake in the crater of the active cinder cone became inactive. Weak strombolian outbursts from 1-3 small vents on the bottom of

  12. Remote sensing and petrological observations on the 2012-2013 fissure eruption at Tolbachik volcano, Kamchatka: Implications for reconstruction of the eruption chronology

    NASA Astrophysics Data System (ADS)

    Melnikov, Dmitry; Volynets, Anna O.

    2015-12-01

    We present a reconstruction of the chronological sequence of events that took place during the first days of the 2012-2013 Tolbachik fissure eruption using petrological data and remote sensing methods. We were forced to use this approach because bad weather conditions did not allow direct observations during the first two days of the eruption. We interpreted infrared images from the scanning radiometer VIIRS Suomi NPP and correlated the output with the results of the geochemical study, including comparison of the ash, deposited at the period from 27 to 29 November, with the samples of lava and bombs erupted from the Menyailov and Naboko vents. We argue that the compositional change observed in the eruption products (the decrease of SiO2 concentration and K2O/MgO ratio, increase of MgO concentration and Mg#) started approximately 24 h after the eruption began. At this time the center of activity moved to the southern part of the fissure, where the Naboko group of vents was formed; therefore, this timeframe also characterizes the timing of the Naboko vent opening. The Naboko group of vents remained active until the end of eruption in September 2013.

  13. Monitoring an eruption fissure in 3D: video recording, particle image velocimetry and dynamics

    NASA Astrophysics Data System (ADS)

    Witt, Tanja; Walter, Thomas R.

    2015-04-01

    The processes during an eruption are very complex. To get a better understanding several parameters are measured. One of the measured parameters is the velocity of particles and patterns, as ash and emitted magma, and of the volcano itself. The resulting velocity field provides insights into the dynamics of a vent. Here we test our algorithm for 3 dimensional velocity fields on videos of the second fissure eruption of Bárdarbunga 2014. There we acquired videos from lava fountains of the main fissure with 2 high speed cameras with small angles between the cameras. Additionally we test the algorithm on videos from the geyser Strokkur, where we had 3 cameras and larger angles between the cameras. The velocity is calculated by a correlation in the Fourier space of contiguous images. Considering that we only have the velocity field of the surface smaller angles result in a better resolution of the existing velocity field in the near field. For general movements also larger angles can be useful, e.g. to get the direction, height and velocity of eruption clouds. In summary, it can be stated that 3D velocimetry can be used for several application and with different setup due to the application.

  14. Fine Mapping and Introgressing a Fissure Resistance Locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice (Oryza sativa L.) kernel fissuring is a major concern of both rice producers and millers. Fissures are small cracks in rice kernels that increase breakage among kernels when transported or milled, which decrease the value of processed rice. This study employed molecular gene tagging methods to ...

  15. Coil spring venting arrangement

    DOEpatents

    McCugh, R.M.

    1975-10-21

    A simple venting device for trapped gas pockets in hydraulic systems is inserted through a small access passages, operated remotely, and removed completely. The device comprises a small diameter, closely wound coil spring which is pushed through a guide temporarily inserted in the access passage. The guide has a central passageway which directs the coil spring radially upward into the pocket, so that, with the guide properly positioned for depth and properly oriented, the coil spring can be pushed up into the top of the pocket to vent it. By positioning a seal around the free end of the guide, the spring and guide are removed and the passage is sealed.

  16. 24 CFR 3280.611 - Vents and venting.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... (a) General. Each plumbing fixture trap shall be protected against siphonage and back pressure, and... 2-inch wet vented drain that carries the waste of not more than one fixture, or, (iii) Two or more... § 3280.611(c)(5) for 3-inch trap arms. (2) Vent pipe areas. Each individually vented fixture with a...

  17. 24 CFR 3280.611 - Vents and venting.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... (a) General. Each plumbing fixture trap shall be protected against siphonage and back pressure, and... 2-inch wet vented drain that carries the waste of not more than one fixture, or, (iii) Two or more... § 3280.611(c)(5) for 3-inch trap arms. (2) Vent pipe areas. Each individually vented fixture with a...

  18. 24 CFR 3280.611 - Vents and venting.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... (a) General. Each plumbing fixture trap shall be protected against siphonage and back pressure, and... 2-inch wet vented drain that carries the waste of not more than one fixture, or, (iii) Two or more... § 3280.611(c)(5) for 3-inch trap arms. (2) Vent pipe areas. Each individually vented fixture with a...

  19. 24 CFR 3280.611 - Vents and venting.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... (a) General. Each plumbing fixture trap shall be protected against siphonage and back pressure, and... 2-inch wet vented drain that carries the waste of not more than one fixture, or, (iii) Two or more... § 3280.611(c)(5) for 3-inch trap arms. (2) Vent pipe areas. Each individually vented fixture with a...

  20. Impact de la preparation des anodes crues et des conditions de cuisson sur la fissuration dans des anodes denses

    NASA Astrophysics Data System (ADS)

    Amrani, Salah

    classifier les differentes fissurations en plusieurs categories en se basant sur certains criteres tels que le type de fissures (horizontale, verticale et inclinee), leurs localisations longitudinales (bas, milieu et haut de l'anode) et transversales (gauche, centrale et droite). Les effets de la matiere premiere, les parametres de fabrication des anodes crues ainsi que les conditions de cuisson sur la fissuration ont ete etudies. La fissuration des anodes denses en carbones cause un serieux probleme pour l'industrie d'aluminium primaire. La realisation de ce projet a permis la revelation de differents mecanismes de fissuration, la classification de fissuration par plusieurs criteres (position, types localisation) et l'evaluation de l'impact de differents parametres sur la fissuration. Les etudes effectuees dans le domaine de cuisson ont donne la possibilite d'ameliorer l'operation et reduire la fissuration des anodes. Le travail consiste aussi a identifier des techniques capables d'evaluer la qualite d'anodes (l'ultrason, la tomographie et la distribution de la resistivite electrique). La fissuration des anodes en carbone est consideree comme un probleme complexe, car son apparition depend de plusieurs parametres repartis sur toute la chaine de production. Dans ce projet, plusieurs nouvelles etudes ont ete realisees, et elles permettent de donner de l'originalite aux travaux de recherches faits dans le domaine de la fissuration des anodes de carbone pour l'industrie de l'aluminium primaire. Les etudes realisees dans ce projet permettent d'ajouter d'un cote, une valeur scientifique pour mieux comprendre le probleme de fissuration des anodes et d'un autre cote, d'essayer de proposer des methodes qui peuvent reduire ce probleme a l'echelle industrielle.

  1. Vent Relief Valve Test

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Shown is the disassembly, examination, refurbishment and testing of the LH2 ( liquid hydrogen) and LOX (liquid oxygen) vent and relief valves for the S-IVB-211 engine stage in support of the Constellation/Ares project. This image is extracted from high definition video and is the highest resolution available.

  2. Instrumentation and measurement of airflow and temperature in attics fitted with ridge and soffit vents

    SciTech Connect

    Romero, M.I.; Brenner, R.J.

    1998-12-31

    This study established a research facility where airflow velocities, temperature, and differential pressures could be measured at the ridge of an attic. Following the construction of a test building, sensors were constructed, calibrated, and installed inside the attic. Paired tests were performed for three different ridge vent treatments; two were rolled type vents and one was a baffled vent. When both attics were fitted with the same ridge vent, the airspeed and differential pressure profiles at the ridge were very similar for both attics, indicating that any observed differences in airspeed and differential pressure were caused by the ridge vent treatment used. The baffled vent and rolled vents were then installed on the ridge of the west and east attics, respectively. The data demonstrated that the baffled ridge vent provided a minimum of twice the ridge airspeed of the rolled vents, when all wind conditions were considered. On the day selected to study the direction of the airflows at the ridge, the baffled vent had airflow speeds at the ridge similar to the rolled vent without fabric backing. The baffled vent allowed air to come out of the attic through both sides of the ridge (negative differential pressures on both sides), while the rolled vent without fabric backing caused air to enter through the south side of the ridge and exit through the north side (positive differential pressure on the south side and negative differential pressure on the north), in effect short-circuiting the vent. The fabric-backed rolled vent allowed attic air to come out of the attic through both sides of the ridge, as did the baffled vent, but the airspeed was slower. The baffled vent was the one with the highest airspeed at the ridge and also had both sides of the vent under negative differential pressure, providing the most effective ventilation.

  3. Methods for monitoring land subsidence and earth fissures in the Western USA

    NASA Astrophysics Data System (ADS)

    Fergason, K. C.; Rucker, M. L.; Panda, B. B.

    2015-11-01

    Depletion of groundwater resources in many deep alluvial basin aquifers in the Western USA is causing land subsidence, as it does in many regions worldwide. Land subsidence can severely and adversely impact infrastructure by changing the ground elevation, ground slope (grade) and through the development of ground cracks known as earth fissures that can erode into large gullies. Earth fissures have the potential to compromise the foundations of dams, levees, and other infrastructure and cause failure. Subsequent to an evaluation of the overall subsidence experienced in the vicinity of subsidence-impacted infrastructure, a detailed investigation to search for earth fissures, and design and/or mitigation of potentially effected infrastructure, a focused monitoring system should be designed and implemented. Its purpose is to provide data, and ultimately knowledge, to reduce the potential adverse impacts of land subsidence and earth fissure development to the pertinent infrastructure. This risk reduction is realized by quantifying the rate and distribution of ground deformation, and to detect ground rupture if it occurs, in the vicinity of the infrastructure. The authors have successfully designed and implemented monitoring systems capable of quantifying rates and distributions of ground subsidence and detection of ground rupture at multiple locations throughout the Western USA for several types of infrastructure including dams, levees, channels, basins, roadways, and mining facilities. Effective subsidence and earth fissure monitoring requires understanding and quantification of historic subsidence, estimation of potential future subsidence, delineation of the risk for earth fissures that could impact infrastructure, and motivation and resources to continue monitoring through time. A successful monitoring system provides the means to measure ground deformation, grade changes, displacement, and anticipate and assess the potential for earth fissuring. Employing multiple

  4. On Small Disturbance Ascent Vent Behavior

    NASA Technical Reports Server (NTRS)

    Woronowicz, Michael

    2015-01-01

    As a spacecraft undergoes ascent in a launch vehicle, its ambient pressure environment transitions from one atmosphere to high vacuum in a matter of a few minutes. Venting of internal cavities is necessary to prevent the buildup of pressure differentials across cavity walls. These pressure differentials are often restricted to low levels to prevent violation of container integrity. Such vents usually consist of fixed orifices, ducts, or combinations of both. Duct conductance behavior is fundamentally different from that for orifices in pressure driven flows governing the launch vehicle ascent depressurization environment. Duct conductance is governed by the average pressure across its length, while orifice conductance is dictated by a pressure ratio. Hence, one cannot define a valid equivalent orifice for a given duct across a range of pressure levels. This presentation discusses development of expressions for these two types of vent elements in the limit of small pressure differentials, explores conditions for their validity, and compares their features regarding ascent depressurization performance.

  5. Study of the deformation mechanism of the Gaoliying ground fissure

    NASA Astrophysics Data System (ADS)

    Cheng, G.; Wang, H.; Luo, Y.; Guo, H.

    2015-11-01

    The Gaoliying ground fissure in Beijing has caused building cracking and road damage, and has seriously influenced city construction. Based on investigations and trenching, the influences of the fault and the variation of groundwater levels on the formation mechanism of the Gaoliying ground fissure were investigated by using FLAC3D. The results indicated that (1) the surface location of Gaoliying fissure is controlled by the underlying normal fault activity, and over pumping further exacerbates development of the ground fissure; (2) when the groundwater level declines, obvious differential settlement occurs at both sides of the ground fissure, in which greater settlement occurs in the vicinity of the hanging wall, the greater the distance from the hanging wall, the smaller the ground subsidence, however smaller ground subsidence occurs in the vicinity of the footwall, the greater the distance from the footwall, the greater the ground subsidence; (3) the vertical velocity of the ground fissure triggered by the fault activity and groundwater decline ranges from 15.5 to 18.3 mm a-1, which is basically in line with the monitoring data. The fault activity contributes about 28-39 %, and the groundwater contributes about 61-72 % to the deformation of the ground fissure, respectively.

  6. 14 CFR 29.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank vents and carburetor vapor vents... Fuel tank vents and carburetor vapor vents. (a) Fuel tank vents. Each fuel tank must be vented from the... addition— (1) The vents must be arranged to avoid stoppage by dirt or ice formation; (2) The...

  7. 14 CFR 25.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank vents and carburetor vapor vents... Fuel tank vents and carburetor vapor vents. (a) Fuel tank vents. Each fuel tank must be vented from the... addition— (1) Each vent must be arranged to avoid stoppage by dirt or ice formation; (2) The...

  8. 14 CFR 25.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel tank vents and carburetor vapor vents... Fuel tank vents and carburetor vapor vents. (a) Fuel tank vents. Each fuel tank must be vented from the... hazard; or (ii) From which fumes could enter personnel compartments. (b) Carburetor vapor vents....

  9. 14 CFR 29.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel tank vents and carburetor vapor vents... Fuel tank vents and carburetor vapor vents. (a) Fuel tank vents. Each fuel tank must be vented from the... during landing, ground operations, or a survivable impact. (b) Carburetor vapor vents. Each...

  10. Staged venting of fuel cell system during rapid shutdown

    DOEpatents

    Keskula, Donald H.; Doan, Tien M.; Clingerman, Bruce J.

    2004-09-14

    A venting methodology and system for rapid shutdown of a fuel cell apparatus of the type used in a vehicle propulsion system. H.sub.2 and air flows to the fuel cell stack are slowly bypassed to the combustor upon receipt of a rapid shutdown command. The bypass occurs over a period of time (for example one to five seconds) using conveniently-sized bypass valves. Upon receipt of the rapid shutdown command, the anode inlet of the fuel cell stack is instantaneously vented to a remote vent to remove all H.sub.2 from the stack. Airflow to the cathode inlet of the fuel cell stack gradually diminishes over the bypass period, and when the airflow bypass is complete the cathode inlet is also instantaneously vented to a remote vent to eliminate pressure differentials across the stack.

  11. Staged venting of fuel cell system during rapid shutdown

    DOEpatents

    Clingerman, Bruce J.; Doan, Tien M.; Keskula, Donald H.

    2002-01-01

    A venting methodology and system for rapid shutdown of a fuel cell apparatus of the type used in a vehicle propulsion system. H.sub.2 and air flows to the fuel cell stack are slowly bypassed to the combustor upon receipt of a rapid shutdown command. The bypass occurs over a period of time (for example one to five seconds) using conveniently-sized bypass valves. Upon receipt of the rapid shutdown command, the anode inlet of the fuel cell stack is instantaneously vented to a remote vent to remove all H.sub.2 from the stack. Airflow to the cathode inlet of the fuel cell stack gradually diminishes over the bypass period, and when the airflow bypass is complete the cathode inlet is also instantaneously vented to a remote vent to eliminate pressure differentials across the stack.

  12. Detail of southeast side of Facility 283. Compare roof vents ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of southeast side of Facility 283. Compare roof vents to those on Facility 226. - U.S. Naval Base, Pearl Harbor, Storehouse for Defense Battalion Type, Between Port Royal Street & Fuller Way, Pearl City, Honolulu County, HI

  13. Airbag vent valve and system

    NASA Technical Reports Server (NTRS)

    Peterson, Leslie D. (Inventor); Zimmermann, Richard E. (Inventor)

    2001-01-01

    An energy absorbing airbag system includes one or more vent valve assemblies for controlling the release of airbag inflation gases to maintain inflation gas pressure within an airbag at a substantially constant pressure during a ride-down of an energy absorbing event. Each vent valve assembly includes a cantilever spring that is flat in an unstressed condition and that has a free end portion. The cantilever spring is secured to an exterior surface of the airbag housing and flexed to cause the second free end portion of the cantilever spring to be pressed, with a preset force, against a vent port or a closure covering the vent port to seal the vent port until inflation gas pressure within the airbag reaches a preselected value determined by the preset force whereupon the free end portion of the cantilever spring is lifted from the vent port by the inflation gases within the airbag to vent the inflation gases from within the airbag. The resilience of the cantilever spring maintains a substantially constant pressure within the airbag during a ride-down portion of an energy absorbing event by causing the cantilever spring to vent gases through the vent port whenever the pressure of the inflation gases reaches the preselected value and by causing the cantilever spring to close the vent port whenever the pressure of the inflation gases falls below the preselected value.

  14. Calcified gallstone fissures: the reversed Mercedes Benz sign.

    PubMed

    Strijk, S P

    1987-01-01

    This article describes the occurrence of an unusual radiating pattern of calcification in the center of large radiolucent gallstones. The radiographic findings are attributed to calcium deposition within the fissures of biliary calculi.

  15. Calcified gallstone fissures: the reversed Mercedes Benz sign.

    PubMed

    Strijk, S P

    1987-01-01

    This article describes the occurrence of an unusual radiating pattern of calcification in the center of large radiolucent gallstones. The radiographic findings are attributed to calcium deposition within the fissures of biliary calculi. PMID:3556975

  16. Visual Observations and Geologic Settings of the Newly-Discovered Black Smoker Vent Sites Across the Galapagos Ridge-Hotspot Intersection

    NASA Astrophysics Data System (ADS)

    Anderson, P.; Haymon, R.; MacDonald, K.; White, S.

    2006-12-01

    Nearly one-fifth of the global mid-ocean ridge is hotspot-affected, yet very little is known about how hotspots affect quantity and distribution of high-temperature hydrothermal vents along the ridge. During the 2005-06 GalAPAGoS expedition, acoustic and plume sensor surveys were conducted across the Galapagos ridge- hotspot intersection, lon. 94.5ºW- lon. 89.5ºW, to map fine scale geologic features and locate hydrothermal plumes emanating from the ridge crest. Where significant plumes were detected, the Medea fiber-optic camera sled was used successfully to find and image high-temperature vents on the seafloor. With Medea we discovered and imaged the first active and recently extinct black smokers known along the entire Galapagos Spreading Center (GSC), and documented the geologic setting of these vents. The Medea survey imaged numerous inactive vents as well as 3 active high-temperature vent fields along the ridge at 94º 04.5'W (Navidad Site), 91º56.2'W (Iguanas Site) and 91º54.3'W (Pinguinos Site). Two recently extinct vent fields also were identified at 91º23.4'-23.7'W and 91º13.8'W. All of the high-temperature vent sites that we identified along the GSC are found above relatively shallow AMC reflectors and are located in the middle 20% of ridge segments. Without exception the vent sites are located along fissures atop constructional axial volcanic ridges (AVR's) composed of relatively young pillow basalts. In some cases, the vents were associated with collapses adjacent to the fissures. The fissures appear to be eruptive sources of the pillow lavas comprising the AVR's. Video images of the chimneys show mature, cylindrical structures, up to 14m high; little diffuse flow; few animals; and some worm casts and dead clam shells, suggesting prior habitation. We conclude that distribution of the vents is controlled by magmatic processes, (i.e., by locations of shallow AMC magma reservoirs and eruptive fissures above dike intrusions), and that there is

  17. Differential compaction mechanism for earth fissures near Casa Grande, Arizona.

    USGS Publications Warehouse

    Jachens, R.C.; Holzer, T.L.

    1982-01-01

    Precise gravity measurements indicate that earth fissures or tension cracks caused by ground-water withdrawal within a 10km2 area SE of Casa Grande are associated with relief on the buried interface between the alluvial aquifer and underlying bedrock. These relations suggest that the fissures are forming in response to localized differential compaction caused by localized variations of aquifer-system thickness. -from Authors

  18. Telencephalic Flexure and Malformations of the Lateral Cerebral (Sylvian) Fissure.

    PubMed

    Sarnat, Harvey B; Flores-Sarnat, Laura

    2016-10-01

    After sagittal division of the prosencephalon at 4.5 weeks of gestation, the early fetal cerebral hemisphere bends or rotates posteroventrally from seven weeks of gestation. The posterior pole of the telencephalon thus becomes not the occipital but the temporal lobe as the telencephalic flexure forms the operculum and finally the lateral cerebral or Sylvian fissure. The ventral part is infolded to become the insula. The frontal and temporal lips of the Sylvian fissure, as well as the insula, all derive from the ventral margin of the primitive telencephalon, hence may be influenced by genetic mutations with a ventrodorsal gradient of expression. The telencephalic flexure also contributes to a shift of the hippocampus from a dorsal to a ventral position, the early rostral pole of the hippocampus becoming caudal and dorsal becoming ventral. The occipital horn is the most recent recess of the lateral ventricle, hence most vulnerable to anatomic variations that affect the calcarine fissure. Many major malformations include lack of telencephalic flexure (holoprosencephaly, extreme micrencephaly) or dysplastic Sylvian fissure (lissencephalies, hemimegalencephaly, schizencephaly). Although fissures and sulci are genetically programmed, mechanical forces of growth and volume expansion are proposed to be mainly extrinsic (including ventricles) for fissures and intrinsic for sulci. In fetal hydrocephalus, the telencephalic flexure is less affected because ventricular dilatation occurs later in gestation. Flexures can be detected prenatally by ultrasound and fetal magnetic resonance imaging and should be described neuropathologically in cerebral malformations. PMID:27590993

  19. Modern Perspectives in the Treatment of Chronic Anal Fissures

    PubMed Central

    Bhardwaj, R; Parker, MC

    2007-01-01

    INTRODUCTION Anal fissures are commonly encountered in routine colorectal practice. Developments in the pharmacological understanding of the internal anal sphincter have resulted in more conservative approaches towards treatment. Simple measures are often effective for early fissures. Glyceryl trinitrate is well established as a first-line pharmacological therapy. The roles of diltiazem and botulinum, particularly as rescue therapy, are not well understood. Surgery has a defined role and should not be discounted completely. METHODS Data were obtained from Medline publications citing ‘anal fissure’. Manual cross-referencing of salient articles was conducted. We have sought to highlight various controversies in the management of anal fissures. FINDINGS Acute fissures may heal spontaneously, although simple conservative measures are sufficient. Idiopathic chronic anal fissures need careful evaluation to decide what therapy is suitable. Pharmacological agents such as glyceryl trinitrate (GTN), diltiazem and botulinum toxin have been subjected to most scrutiny. Though practices in the UK vary, GTN or diltiazem would be suitable as first-line therapy with botulinum toxin used as rescue treatment. Sphincterotomy is indicated for unhealed fissures; fissurectomy has been revisited and advancement flaps have a role in patients in whom sphincter division is not suitable. PMID:17688717

  20. Changing patterns of treatment for chronic anal fissure.

    PubMed

    Farouk, R; Gunn, J; Duthie, G S

    1998-05-01

    To assess changing patterns of treatment for chronic anal fissure, a retrospective analysis of treatment for chronic anal fissure within one hospital between January 1990 and December 1996 was undertaken. A total of 221 patients received treatment for a chronic anal fissure in this period, of whom 209 had a surgical procedure. Manual dilatation of the anus was performed in 21 patients (10%) and has not been performed since 1995. Lateral internal sphincterotomy was performed in 183 patients (88%) and continues to be the mainstay of treatment. Five female patients (2%) were identified as having a sphincter defect by anal manometry combined with endoanal ultrasound and were treated by an anal advancement flap. From 1996 onwards, 15 patients (7%) were treated by topical glyceryl trinitrate (GTN) paste as the first line of treatment. Of these patients, nine have experienced healing of their fissure, and three have had relief of pain without healing of the fissure. Three have gone on to have a lateral internal sphincterotomy. Lateral internal sphincterotomy remains the primary form of treatment for chronic anal fissure. GTN cream has increasingly been offered as preliminary treatment over the last 12 months. Perioperative use of endoanal ultrasound allowed identification of patients who may be at high risk of postoperative incontinence from a sphincterotomy. An anal advancement flap has been used as an alternative surgical approach for these patients.

  1. Two Vent Fields Discovered at the Ultraslow Spreading Arctic Ridge System

    NASA Astrophysics Data System (ADS)

    Pedersen, R. B.; Thorseth, I. H.; Hellevang, B.; Schultz, A.; Taylor, P.; Knudsen, H. P.; Steinsbu, B. O.

    2005-12-01

    Two high-temperature vent fields were discovered at the Mohns Ridge during an expedition with the Norwegian research vessel "G.O. Sars" in July 2005. Both vent fields are located within the southernmost segment of the Mohns Ridge approximately 50 km north of the West Jan Mayen Fracture Zone. Water depths along this segment range from 3800 meters close to the fracture zone to ~500 meters at the segment centre where the vent fields are located. The largest field - named "Gallionella Garden" - is situated within a rift graben where high- and low-temperature venting occurs along ridge-parallel normal faults and fissures. Presently we have documented high- and low-temperature venting along more then 2 km of the fault and fissure system in the area. The high-temperature venting takes place at around 550 mbsl at the base of a 100 meter high fault wall and was traced ~500 meters along strike. The field consists of at least 10 major vent sites, each composed of multiple chimneys that are up to 5-10 meters tall. There are also large areas of diffuse flow. The temperature of the vent fluids was measured to be above 260°C at a chimney orifice. This is at the boiling point of seawater at these water depths, and gas bubbling was observed at several of the vent sites. A sample of the top of a chimney consists of anhydrite, barite, sphalerite and pyrite. Outside the high-temperature vent area mounds of ferric iron are abundant. Such deposits have presently been traced along ~2 km of the faults and fissure system in the area. The deposits are predominantly made up of branching and twisted stalks comparable to those formed by the iron oxidizing bacteria Gallionella ferruginea showing that the precipitation is mediated by microbial activity. The temperatures below the upper crust of a mound were measured to be one degree above the ambient water temperature. The Fe-oxyhydroxides show Nd-isotope compositions similar to the basaltic crust and Sr-isotope compositions close to that of

  2. Tapped-Hole Vent Path

    NASA Technical Reports Server (NTRS)

    Chandler, J. A.

    1983-01-01

    Long helical vent path cools and releases hot pyrotechnical gas that exits along its spiraling threads. Current design uses 1/4-28 threads with outer diameter of stud reduced by 0.025 in. (0.62 mm). To open or close gassampler bottle, pyrotechnic charges on either one side or other of valve cylinder are actuated. Gases vented slowly over long path are cool enough to present no ignition hazard. Vent used to meter flow in refrigeration, pneumaticcontrol, and fluid-control systems by appropriately adjusting size and length of vent path.

  3. Measurement of the velocity field behind the automotive vent

    NASA Astrophysics Data System (ADS)

    Ležovič, Tomáš; Lízal, František; Jedelský, Jan; Jícha, Miroslav

    2012-04-01

    Passenger comfort in a personal vehicle cabin strongly depends on the appropriate function of the cabin ventilation system. Great attention is therefore paid to the effective functioning of the automotive vents. Various techniques can be employed to evaluate the proper formation of the flow behind the ventilation outlet. Constant Temperature Anemometry (CTA) was used in our case for accurate measurement of the velocity field and consequent assessment of jet boundaries and jet axis. A novel methodology has been developed for the simulation of realistic conditions when using just a single vent under laboratory conditions instead of the complete vehicle ventilation system. A special technique has also been developed for determination of the terminal inclination angles of vent vanes for the particular vent type, which can be completely closed by the adjustable horizontal vanes. A two wire CTA probe was used for measurement of the actual velocity over predefined planes, which were specified according to smoke visualization. Mean velocities and the turbulence intensity were evaluated on the basis of the obtained data and are presented in a form of charts. Both jet boundary and orientation of the jet for a given setup of the vent are important characteristics of particular vent type. Effectiveness of different vents could be compared using our methodology and hence contribute to development of advanced ventilation system.

  4. A conceptual model of the hydrological influence of fissures on landslide activity

    NASA Astrophysics Data System (ADS)

    Krzeminska, D. M.; Bogaard, T. A.; van Asch, Th. W. J.; van Beek, L. P. H.

    2012-06-01

    Hydrological processes control the behaviour of many unstable slopes, and their importance for landslide activity is generally accepted. The presence of fissures influences the storage capacity of a soil and affects the infiltration processes of rainfall. The effectiveness of the fissure network depends upon fissure size, their spatial distribution, and connectivity. Moreover, fissure connectivity is a dynamic characteristic, depending on the degree of saturation of the medium. This research aims to investigate the influence of the fissure network on hydrological responses of a landslide. Special attention is given to spatial and temporal variations in fissure connectivity, which makes fissures act both as preferential flow paths for deep infiltration (disconnected fissures) and as lateral groundwater drains (connected fissures). To this end, the hydrological processes that control the exchange of water between the fissure network and the matrix have been included in a spatially distributed hydrological and slope stability model. The ensuing feedbacks in landslide hydrology were explored by running the model with one year of meteorological forcing. The effect of dynamic fissure connectivity was evaluated by comparing simulations with static fissure patterns to simulations in which these patterns change as a function of soil saturation. The results highlight that fissure connectivity and fissure permeability control the water distribution within landslides. Making the fissure connectivity function of soil moisture results in composite behaviour spanning the above end members and introduces stronger seasonality of the hydrological responses.

  5. Safe venting of hydrogen

    SciTech Connect

    Stewart, W.F.; Dewart, J.M.; Edeskuty, F.J.

    1990-01-01

    The disposal of hydrogen is often required in the operation of an experimental facility that contains hydrogen. Whether the vented hydrogen can be discharged to the atmosphere safely depends upon a number of factors such as the flow rate and atmospheric conditions. Calculations have been made that predict the distance a combustible mixture can extend from the point of release under some specified atmospheric conditions. Also the quantity of hydrogen in the combustible cloud is estimated. These results can be helpful in deciding of the hydrogen can be released directly to the atmosphere, or if it must be intentionally ignited. 15 refs., 5 figs., 2 tabs.

  6. Tornado protection by venting

    SciTech Connect

    Cavanagh, C.A.

    1987-01-01

    The purpose of this paper is to demonstrate the ability to protect a modern nuclear power plant from the effects of a tornado by the use of a system of venting in all safety-related structures outside of the containment. The paper demonstrates this by presenting a method of analysis and of equipment selection that fully complies with the intent and the letter of applicable federal regulatory guides. A report of an actual tornado in the City of Kalamazoo, Michigan, suggests that the concept of sealing a plant during a tornado may not always be applicable.

  7. Arteries and Veins of the Sylvian Fissure and Insula: Microsurgical Anatomy.

    PubMed

    Delion, Matthieu; Mercier, Philippe; Brassier, Gilles

    2016-01-01

    We present a vascular anatomical study of the arteries and veins of the sylvian fissure and insula.A good knowledge of the sylvian fissure, the insula, and their vascular relationship would seem mandatory before performing surgery in this area, whatever the type of surgery (aneurysms, arteriovenous malformations, insular tumors).We start with the sylvian fissure and insula morphology, followed by the MCA description and its perforators, with special attention paid to the insular perforators. We demonstrate that the long insular perforators penetrating in the superior part of the posterior short gyrus and long gyri vascularize, respectively, the corticonuclear and corticospinal fasciculi. We particularly insist too on three anatomical constants regarding the vascularization of the insula, already described in the literature: The superior periinsular sulcus is the only sulcus on the lateral surface of the brain without an artery along its axis; the superior branch of the MCA supplies the anterior insular pole and both the anterior and middle short gyri in 100 % of cases; in at least 90 % of cases, the artery that supplied the central insular sulcus continued on to become the central artery.We end with the anatomical study of the veins and cisterns.

  8. Resin infiltration of fissure caries with various techniques of pretreatment in vitro.

    PubMed

    Lausch, Julian; Paris, Sebastian; Selje, Timo; Dörfer, Christof E; Meyer-Lueckel, Hendrik

    2015-01-01

    The resin infiltration technique might be used for occlusal caries lesions in order to arrest their progression. This in vitro study evaluated the influence of various modifications of the infiltration technique on the penetration abilities of the infiltrant into occlusal lesions. Extracted human molars and premolars (n = 140) with non-cavitated white spot lesions were randomly allocated to 7 groups. As control, specimens were etched with 15% hydrochloric acid (HCl) gel for 120 s and resin infiltrated for 180 s (Icon; DMG). As modification HCl gel reduced in surface tension and viscosity with and without abrasives was applied using 3 different types of brushes either to oscillate or rub the HCl gel onto the enamel surface. The median maximum lesion depth was 1,232 µm (interquartile range 882-1,513). Compared with the control procedure [23% (16/50)] a higher percentage penetration was observed if the HCl gel was mixed with a small amount of abrasives were rubbed into the fissures using a modified brush with stiff bristles that were adjusted to the fissure relief for either 120 s [100% (64/100)] or 30 s [98% (61/100); p < 0.05; Mann-Whitney test]. All other experimental treatments resulted in penetration results in-between. It can be concluded that the use of an abrasive HCl gel in conjunction with a modified brush mostly enhances resin infiltration into fissure caries lesions. PMID:25427531

  9. EVALUATION OF SOIL VENTING APPLICATION

    EPA Science Inventory

    The ability of soil venting to inexpensively remove large amounts of volatile organic compounds (VOCs) from contaminated soils is well established. However, the time required using venting to remediate soils to low contaminant levels often required by state and federal regulators...

  10. Open Fissure Folds record coseismic loading and postseismic stress relaxation

    NASA Astrophysics Data System (ADS)

    Nüchter, Jens-Alexander

    2015-03-01

    Open Fissure Folds hosted by high pressure/low temperature metamorphic rocks of south Evia (Greece) are introduced, their structural and microstructural record is analysed, and a mechanical model is proposed. Open Fissure Folds are preserved as at least two parallel folded quartz-feldspar veins separated by narrow buckled rock columns. The veins originated as tensile cracks that propagated in the middle crust driven by high differential stress. Features diagnostic for Open Fissure Folds indicate that the rock columns represented the layers of high viscosity, and not the veins as consistently reported in many previous studies on folded veins. This record is taken to indicate that buckling of the rock columns initiated after arrest of the fractures and terminated prior to complete vein sealing. Accordingly, mechanical decoupling by open fissures allowed for buckling of the rock columns in response to episodic creep of the host rocks according to stress relaxation, as expected for postseismic deformation in the earthquake cycle. I propose that the parental fractures propagated in response to quasi-instantaneous coseismic loading of the middle crust. Buckling was attributed to transient postseismic creep and stress relaxation. Complete sealing of the veins occurred when stresses were largely relaxed. Each Open Fissure Fold records the stress and strain history of a single earthquake.

  11. Vesicle size analysis of magmatic and phreatomagmatic phases of the 934-40 AD Eldgjá fissure eruption, southern Iceland

    NASA Astrophysics Data System (ADS)

    Thordarson, T.; Moreland, W.; Houghton, B. F.

    2014-12-01

    Eldgjá is a ~75 km volcanic fissure which erupted in the middle of the 10th century. It belongs to the Katla volcanic system and is of the mixed-cone row type. The eruption lasted several years and produced two large lava fields (18.3 km3) and a widespread basaltic tephra deposit (4.5 km3 or 1.3 km3 DRE). Proximal tephra deposits are up to 5 m thick and contain as many as 10 sub-units which vary in thickness parallel to the fissure, indicating multiple points of origin. Many of the lowest units were produced by phreatomagmatic activity and dispersion of these units indicate an origin below the Mýrdalsjökull glacier. Two sections were chosen to represent magmatic and phreatomagmatic activity. A 3.7 m section at Skælingar, 0.5 km south-east of Eldgjá, represents the magmatic products. The phreatomagmatic products are represented by a 2.7 m thick section at Stóragil, located 10-15 km south and east of the vent system. The sampled phreatomagmatic part of the section is 1.12 m thick. These sections were logged and then each sub-unit was sampled for density analysis which involves picking 100 clasts in the 8 to 32 mm size range from horizons less than 5 cm thick. Thin-sections were then made from representative clasts of each sub-unit. Nested images of these thin-sections were analysed for vesicle size and shape. The magmatic clasts have unimodal, normal to moderately log-normal density distributions with a mean density of 7900-7500 kg.m-3 (60-70% vesicularity) and a range of around 8600 kg.m-3 (40% vesicularity). The log-normal distribution of some samples may be explained by the inclusion of previously degassed magma in the eruption. The section at Stóragil contains both phreatomagmatic and magmatic products. The phreatomagmatic samples have characteristic plateau-like distributions with a mean density of 7200-7500 kg.m-3 (70-80% vesicularity) and a range of around 8420 kg.m-3 (45% vesicularity). One layer shows a change from phreatomagmatic to magmatic

  12. Drivers of explosivity and elevated hazard in basaltic fissure eruptions: The 1913 eruption of Ambrym Volcano, Vanuatu (SW-Pacific)

    NASA Astrophysics Data System (ADS)

    Németh, Károly; Cronin, Shane J.

    2011-04-01

    Fissure-eruptions along linear structures can extend for several tens of kilometres with distinct separate manifestations of volcanism along their length. They typically involve low-viscosity mafic magmas forming long lava flows and cinder cones. Eruptions in 1894 and 1913 on Ambrym volcano, Vanuatu, showed how these mildly explosive eruptions can rapidly transform into violent explosive events, producing significant hazard and widespread volcanic ash clouds. During the 1913 episode, a fissure began in the central caldera and basaltic magmas broke out in a series of locations down the island's western flank. In all sites over 100 m in elevation, fissure outbreaks produced vigorous lava fountains and highly fluid lava flows that travelled rapidly to the shoreline. When the outbreaks propagated along the island's axis into coastal plain areas, a climactic series of explosive eruptions occurred, producing a 1.2 km long by 600 m wide maar and tephra ring. A further small tuff ring was formed later, creating a temporary island 400 m offshore. The onshore tephra ring destroyed a hospital and associated buildings. Its last evacuating occupants were close witnesses to the eruption processes. Deposits exposed in the lower portion of the tephra ring show that this part of the eruption began with a mild phreatomagmatic explosive eruption from a narrow vent, followed by a magmatic scoria-producing phase. Subsequently a complex sequence of highly explosive phreatomagmatic eruptions occurred, producing pyroclastic surges, along with repeated distinctive breccia-horizons, rich in coral and lava country rock. These features tally with eye-witness accounts to indicate that the main eruption phase was produced by a periodically shifting locus of phreatomagmatic fragmentation and eruption along a single E-W fissure. The glassy and vesicle-poor pyroclasts produced during this eruption phase were dominantly fragmented in a brittle manner by magma water interaction. Low volatile content

  13. Asymmetries in the cerebral dimensions and fissures of the dog.

    PubMed

    Tan, U; Calişkan, S

    1987-02-01

    The surface dimensions and fissures of the right and left cerebral hemispheres were compared in dogs. The right hemisphere was significantly larger in length and height than the left hemisphere; there was no significant difference in the width of the right and left hemispheres. The mean length of the cruciate sulcus did not significantly differ on the right and left sides except individual for asymmetries. The difference in the mean length of the right and left Sylvian fissures was not significant, but the right Sylvian fissure was significantly lower than the left. The base of the right planum temporale tended to be larger than the left. These anatomical asymmetries did not correlate with paw preference. The data are consistent with notion that asymmetrical patterns cannot be a distinctive feature of the human brain.

  14. Cochlear implant electrode array misplaced in Hyrtl's fissure.

    PubMed

    Mouzali, Amina; Ouennoughi, Kheiredidine; Haraoubia, Mohamed-Salah; Zemirli, Omar; Triglia, Jean Michel

    2011-11-01

    Hyrtl's fissure is a cleft that is present in the developing fetal petrous temporal bone and extends from the area inferior to the round window to the meninges of the posterior fossa. Persistent Hyrtl's fissure, due to incomplete ossification, is considered a rare temporal bone malformation, and is a known cause of perilabyrinthine cerebrospinal fluid fistula. Very few cases are reported as being at risk of complication of cochlear implant surgery. Here we report the case of an 8-year-old boy with misplacement of an electrode array in Hyrtl's fissure. The diagnosis was made postoperatively, since cochlear implant failure was suspected from non-auditory responses. Computed tomography (CT) revealed the extracochlear location of the electrode array. We emphasize the role of presurgical imaging CT and magnetic resonance imaging in detecting temporal bone abnormalities, and we discuss the value of intraoperative auditory nerve response telemetry and postoperative radiological evaluation in diagnosing cochlear implant misplacement.

  15. 40 CFR Table 1 to Subpart G of... - Process Vents-Coefficients for Total Resource Effectiveness for Existing Source Nonhalogenated...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Process Vents-Coefficients for Total Resource Effectiveness for Existing Source Nonhalogenated and Halogenated Vent Streams 1 Table 1 to Subpart... Source Nonhalogenated and Halogenated Vent Streams Type of Stream Control Device Basis Values...

  16. 40 CFR Table 1 to Subpart G of... - Process Vents-Coefficients for Total Resource Effectiveness for Existing Source Nonhalogenated...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Process Vents-Coefficients for Total Resource Effectiveness for Existing Source Nonhalogenated and Halogenated Vent Streams 1 Table 1 to Subpart... Source Nonhalogenated and Halogenated Vent Streams Type of Stream Control Device Basis Values...

  17. 40 CFR Table 1 to Subpart G of... - Process Vents-Coefficients for Total Resource Effectiveness for Existing Source Nonhalogenated...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Process Vents-Coefficients for Total Resource Effectiveness for Existing Source Nonhalogenated and Halogenated Vent Streams 1 Table 1 to Subpart... Source Nonhalogenated and Halogenated Vent Streams Type of Stream Control Device Basis Values...

  18. 40 CFR Table 1 to Subpart G of... - Process Vents-Coefficients for Total Resource Effectiveness for Existing Source Nonhalogenated...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Process Vents-Coefficients for Total Resource Effectiveness for Existing Source Nonhalogenated and Halogenated Vent Streams 1 Table 1 to Subpart... Source Nonhalogenated and Halogenated Vent Streams Type of Stream Control Device Basis Values...

  19. Stove with co-axial vent and flue design

    SciTech Connect

    Hyatt, J.R.

    1983-02-15

    The present invention relates to a stove of the type having a firebox and a second outer wall that defines an air passageway around the fire-box. Provided with the stove is a fan for forcing air around the defined air passageway for collecting heat from a burning fire within the firebox. A flue is communicatively connected with the firebox and extends therefrom through the defined air passageway and on through the outer wall structure of the stove. Co-axially disposed around the flue and communicatively connected with the air passageway is a vent for directing heated air from the stove. The co-axial relationship of the vent and flue assures that the flue gases must pass within the heated air passing in the vent or vice versa, and this gives rise to a very efficient stove inasmuch as a substantial portion of the heat associated with the flue gases being exhausted is transferred to the vented air.

  20. Provisions for containment venting in Germany

    SciTech Connect

    Wilhelm, J.G.

    1997-08-01

    In this short paper an overlook is given of the systems developed in Germany for filtered containment venting and their implementation in nuclear power plants. More information on the development can be found in the Proceedings of the DOE/NRC Aircleaning Conferences. In Germany, 28.8 % of the electric energy is produced by 19 nuclear power reactors. No new power reactor is expected to be built at least within the next ten years, but France and Germany cooperate in the development of a future European Power Reactor (ERP). This reactor type will be fitted with a core catcher and passive cooling in order to avoid serious consequences of a hypothetical core meltdown accident so that provisions for containment venting are not required. 3 refs., 6 figs., 1 tab.

  1. Purkinje cell age-distribution in fissures and in foliar crowns: a comparative study in the weaver cerebellum.

    PubMed

    Martí, Joaquín; Santa-Cruz, M C; Bayer, Shirley A; Ghetti, Bernardino; Hervás, José P

    2007-12-01

    Generation and settling of Purkinje cells (PCs) are investigated in the weaver mouse cerebellum in order to determine possible relationships with the fissuration pattern. Tritiated thymidine was supplied to pregnant females at the time that these neurons were being produced. Autoradiography was then applied on brain sections obtained from control and weaver offspring at postnatal (P) day 90. This makes it possible to assess the differential survival of neurons born at distinct embryonic times on the basis of the proportion of labeled cells located at the two foliar compartments: fissures and foliar crowns. Our data show that throughout the surface contour of the vermal lobes, generative programs of PCs were close between wild type and homozygous weaver. Similar data were found in the lobules of the lateral hemisphere. On the other hand, the loss of PCs in weaver cerebella can be related to foliar concavities or convexities depending on the vermal lobe or the hemispheric lobule studied. Lastly, we have obtained evidence that late-generated PCs of both normal and mutant mice were preferentially located in fissures. These quantitative relationships lead us to propose a model in which the final distribution of PCs through the vermal contour would be coupled to two factors: the cortical fissuration patterning and a "time-sequential effect" of weaver mutation.

  2. Potential biomass in deep-sea hydrothermal vent ecosystem

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Takai, K.

    2012-12-01

    Since the first discovery of black smoker vents hosting chemosynthetic macrofaunal communities (Spiess et al., 1980), submarine hydrothermal systems and associated biota have attracted interest of many researchers (e.g., Humphris et al., 1995; Van Dover, 2000; Wilcock et al., 2004). In the past couple of decades, particular attention has been paid to chemolithoautotrophic microorganisms that sustain the hydrothermal vent-endemic animal communities as the primary producer. This type of microorganisms obtains energy from inorganic substances (e.g., sulfur, hydrogen, and methane) derived from hydrothermal vent fluids, and is often considered as an important modern analogue to the early ecosystems of the Earth as well as the extraterrestrial life in other planets and moons (e.g., Jannasch and Mottl, 1985; Nealson et al., 2005; Takai et al., 2006). Even today, however, the size of this type of chemosynthetic deep-sea hydrothermal vent ecosystem is largely unknown. Here, we present geophysical and geochemical constraints on potential biomass in the deep-sea hydrothermal vent ecosystem. The estimation of the potential biomass in the deep-sea hydrothermal vent ecosystem is based on hydrothermal fluid flux calculated from heat flux (Elderfield and Schltz, 1996), maximum chemical energy available from metabolic reactions during mixing between hydrothermal vent fluids and seawater (McCollom, 2007), and maintenance energy requirements of the chemolithoautotrophic microorganisms (Hoehler, 2004). The result shows that the most of metabolic energy sustaining the deep-sea hydrothermal vent ecosystem is produced by oxidation reaction of reduced sulfur, although some parts of the energy are derived from hydrogenotrophic and methanotrophic reactions. The overall total of the potential biomass in deep-sea hydrothermal vent ecosystem is calculated to be much smaller than that in terrestrial ecosystems including terrestrial plants. The big difference in biomass between the

  3. Dental Pit and Fissure Sealants: Implications for School Health Personnel.

    ERIC Educational Resources Information Center

    McCormack-Brown, K. R.; And Others

    1989-01-01

    To promote good personal hygiene practices in students, school health personnel must be informed about dental pit and fissure sealants and related programs. Adoption and maintenance of such programs may depend on the success of school health personnel in educating administrators and policymakers. (SM)

  4. Cement penetration after patella venting.

    PubMed

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement.

  5. Cement penetration after patella venting.

    PubMed

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement. PMID:19010682

  6. 2D models of gas flow and ice grain acceleration in Enceladus' vents using DSMC methods

    NASA Astrophysics Data System (ADS)

    Tucker, Orenthal J.; Combi, Michael R.; Tenishev, Valeriy M.

    2015-09-01

    The gas distribution of the Enceladus water vapor plume and the terminal speeds of ejected ice grains are physically linked to its subsurface fissures and vents. It is estimated that the gas exits the fissures with speeds of ∼300-1000 m/s, while the micron-sized grains are ejected with speeds comparable to the escape speed (Schmidt, J. et al. [2008]. Nature 451, 685-688). We investigated the effects of isolated axisymmetric vent geometries on subsurface gas distributions, and in turn, the effects of gas drag on grain acceleration. Subsurface gas flows were modeled using a collision-limiter Direct Simulation Monte Carlo (DSMC) technique in order to consider a broad range of flow regimes (Bird, G. [1994]. Molecular Gas Dynamics and the Direct Simulation of Gas Flows. Oxford University Press, Oxford; Titov, E.V. et al. [2008]. J. Propul. Power 24(2), 311-321). The resulting DSMC gas distributions were used to determine the drag force for the integration of ice grain trajectories in a test particle model. Simulations were performed for diffuse flows in wide channels (Reynolds number ∼10-250) and dense flows in narrow tubular channels (Reynolds number ∼106). We compared gas properties like bulk speed and temperature, and the terminal grain speeds obtained at the vent exit with inferred values for the plume from Cassini data. In the simulations of wide fissures with dimensions similar to that of the Tiger Stripes the resulting subsurface gas densities of ∼1014-1020 m-3 were not sufficient to accelerate even micron-sized ice grains to the Enceladus escape speed. In the simulations of narrow tubular vents with radii of ∼10 m, the much denser flows with number densities of 1021-1023 m-3 accelerated micron-sized grains to bulk gas speed of ∼600 m/s. Further investigations are required to understand the complex relationship between the vent geometry, gas source rate and the sizes and speeds of ejected grains.

  7. Characterization of Six Vent Fields Within the Lau Basin

    NASA Astrophysics Data System (ADS)

    Tivey, M. K.; Craddock, P.; Seewald, J.; Ferrini, V.; Kim, S.; Mottl, M.; Sterling, N. A.; Reysenbach, A.; Wheat, C. G.

    2005-12-01

    Six active vent fields on the Valu Fa Ridge and Eastern Lau Spreading Center were successfully characterized on R/V Melville cruise TUIM05MV. The Kilo Moana (20deg3.2'S), Tow Cam (20deg19'S), and ABE (20deg45.6-46'S) vent fields were first noted during two R/V Kilo Moana cruises (in April (F. Martinez, Chief Scientist) and Sept (C. Langmuir, Chief Scientist) 2004). A fourth vent field, Mariner at 22deg10.8'S, was located Sept 2004 during the Shinkai 6500 program (K. Takai, Chief Scientist) using data from previous cruises. The fifth vent field examined was the Vai Lili vent field at 22deg12.95'S (Fouquet et al., 1991, Nature 349). On the TUIM05MV cruise, a sixth large active vent field was found at 21deg59.4'S using Jason2 and data from multiple CTD tow-yos, following up on plume observations provided by the Martinez et al. cruise. Tasks conducted to characterize each vent field included 1) detailed SM2000 bathymetric surveys; 2) down-looking and/or forward-looking camera surveys to create photomosaics of megafauna distributions; 3) recovery of biological, rock (basalt and sulfide), and fluid samples, and microbiological sampling of sulfide and diffuse fluid samples; 4) MOCNESS tows to recover larval plankton from plumes; 5) CTD casts to collect plume particles. At the Kilo Moana, Tow Cam, ABE and Tui Malila vent fields, hydrothermal activity occurs in proximity to major faults. At Kilo Moana, active venting occurs in three areas from ~5m tall, branched structures as focused, high temperature flow (to 333C) through chalcopyrite (Cp)- and/or wurtzite (Zn)- lined conduits and as diffuse flow through beehive-type structures. At Tow Cam high temperature (to 330C) active venting occurs in two areas at the base of a western fault from Cp- and/or Zn-lined conduits; diffuse flow exits basalt east of the black smoker areas. Within the ABE vent field there are three large areas of active venting spaced 150 to 300 m apart along NNE trending faults and benches; fluid exits

  8. Complete genome sequence of the thermophilic sulfur-reducer Desulfurobacterium thermolithotrophum type strain (BSAT) from a deep-sea hydrothermal vent

    SciTech Connect

    Goker, Markus; Daligault, Hajnalka E.; Mwirichia, Romano; Lapidus, Alla L.; Deshpande, Shweta; Pagani, Ioanna; Tapia, Roxanne; Cheng, Jan-Fang; Goodwin, Lynne A.; Pitluck, Sam; Liolios, Konstantinos; Ivanova, N; Mavromatis, K; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Han, Cliff; Land, Miriam L; Hauser, Loren John; Pan, Chongle; Brambilla, Evelyne-Marie; Rohde, Manfred; Spring, Stefan; Sikorski, Johannes; Wirth, Reinhard; Detter, J. Chris; Woyke, Tanja; Bristow, James; Eisen, Jonathan; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter

    2011-01-01

    Desulfurobacterium thermolithotrophum L'Haridon et al. 1998 is the type species of the ge- nus Desulfurobacterium which belongs to the family Desulfurobacteriaceae. The species is of interest because it represents the first thermophilic bacterium that can act as a primary pro- ducer in the temperature range of 45-75 C (optimum 70 C) and is incapable of growing un- der microaerophilic conditions. Strain BSAT preferentially synthesizes high-melting-point fatty acids (C18 and C20) which is hypothesized to be a strategy to ensure the functionality of the membrane at high growth temperatures. This is the second completed genome sequence of a member of the family Desulfurobacteriaceae and the first sequence from the genus Desulfu- robacterium. The 1,541,968 bp long genome harbors 1,543 protein-coding and 51 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  9. Monitoring of the volcanic rock compositions during the 2012-2013 fissure eruption at Tolbachik volcano, Kamchatka

    NASA Astrophysics Data System (ADS)

    Volynets, Anna O.; Edwards, Benjamin R.; Melnikov, Dmitry; Yakushev, Anton; Griboedova, Irina

    2015-12-01

    Here we present the results from monitoring of the composition of rocks produced during the 2012-2013 fissure eruption at Tolbachik volcano (FTE). Major and trace element concentrations in 75 samples are reported. Products of this eruption are represented by high alumina basaltic trachyandesites with higher alkalis and titanium contents than in all previously studied rocks of the Tolbachik monogenetic volcanic field. Rocks erupted during the first three days (27-30 November) from the northern (also called Menyailov) group of vents are the most silica- and alkali-rich (SiO2 concentrations up to 55.35 wt.% and K2O up to 2.67 wt.%). From December onwards, when the eruptive activity switched from the Menyailov vents to the southern (Naboko) group of vents, silica content dropped by 2 wt.%, concentrations of MgO, FeO, TiO2 and Mg# increased, and K2O and Na2O concentrations and K2O/MgO ratio decreased. For the rest of the eruption the compositions of rocks remained constant and homogeneous; no systematic compositional differences between lava, bombs and scoria samples are evident. Trace element distributions in the rocks of the Menyailov and Naboko vent lavas are relatively uniform; Menyailov lavas have slightly higher Th, Nb, Hf, Y, and HREE concentrations than the Naboko vent lavas at more or less constant element ratios. We explain the initial change in geochemistry by tapping of a slightly cooler and fractionated (~ 3% Mt and 8% Cpx) upper part of the magma storage zone before the main storage area began to feed the eruption. Thermodynamic constraints show that apparent liquidus temperatures varied from 1142 °C to 1151 °C, and thermodynamic modeling shows that variations in compositions are consistent with a high degree of low pressure (100-300 MPa), nominally anhydrous fractionation of a parent melt compositionally similar to the 1975 Northern Breakthrough high-Mg basalt. Geochemistry, petrological observations and modeling are in agreement with the newly erupted

  10. Innovations in chronic anal fissure treatment: A systematic review

    PubMed Central

    Poh, Aaron; Tan, Kok-Yang; Seow-Choen, Francis

    2010-01-01

    A chronic anal fissure is a common perianal condition. This review aims to evaluate both existing and new therapies in the treatment of chronic fissures. Pharmacological therapies such as glyceryl trinitrate (GTN), Diltiazem ointment and Botulinum toxin provide a relatively non-invasive option, but with higher recurrence rates. Lateral sphincterotomy remains the gold standard for treatment. Anal dilatation has no role in treatment. New therapies include perineal support devices, Gonyautoxin injection, fissurectomy, fissurotomy, sphincterolysis, and flap procedures. Further research is required comparing these new therapies with existing established therapies. This paper recommends initial pharmacological therapy with GTN or Diltiazem ointment with Botulinum toxin as a possible second line pharmacological therapy. Perineal support may offer a new dimension in improving healing rates. Lateral sphincterotomy should be offered if pharmacological therapy fails. New therapies are not suitable as first line treatments, though they can be considered if conventional treatment fails. PMID:21160880

  11. The effect of vegetation on infiltration in shallow soils underlain by fissured bedrock

    NASA Astrophysics Data System (ADS)

    Stothoff, S. A.; Or, D.; Groeneveld, D. P.; Jones, S. B.

    1999-05-01

    Mean annual infiltration above the high-level waste repository proposed to be sited at Yucca Mountain, Nevada, has a large impact on assessments of repository performance. Ongoing investigations of infiltration processes have identified the relatively horizontal caprock environment above portions of the repository as a potentially large source of infiltrating waters, due to shallow, permeable soils above a moderately welded tuff with large soil-filled fissures. The combination of shallow soils and fissured bedrock allows rapid penetration of wetting pulses to below the rooting zone. Plant uptake can strongly reduce net infiltration in arid environments with high water storage capacity, and, despite the low water storage capacity, there is a relatively high vegetation density in this environment. The apparent discrepancy between high vegetation density and low water storage motivates the study of plant-hydrologic interactions in this semiarid environment. Field observations were coupled with plant- and landscape-scale models to provide insight into plant-hydrologic interactions. Several lines of evidence, including: (i) linear plant growth features observed on aerial photographs; (ii) comparisons of plant cover within the fissured environment and comparable environments lacking fissures; and (iii) direct excavations, all suggest that the widely spaced soil-filled fissures are conducive to plant growth even when fissures are buried at soil depths exceeding 30 cm. Results from a mechanistic simulation model for root growth into fissures suggest that the additional (sheltered) plant-available soil water within fissures provides a competitive advantage for plant establishment. Therefore, plants that germinate above a fissure are more likely to survive, in turn developing linear features above fissures. Having established that plants preferentially root within soil-filled fissures in the caprock environment, a set of simulations were performed to examine the hydrologic

  12. Injectabilite des coulis de ciment dans des milieux fissures

    NASA Astrophysics Data System (ADS)

    Mnif, Thameur

    Le travail presente ici est un bilan du travaux de recherche effectues sur l'injectabilite des coulis de ciment dans lu milieux fissures. Un certain nombre de coulis a base de ciment Portland et microfin ont ete selectionnes afin de caracteriser leur capacite a penetrer des milieux fissures. Une partie des essais a ete menee en laboratoire. L'etude rheologique des differents melanges a permis de tester l'influence de l'ajout de superplastifiant et/ou de fumee de silice sur la distribution granulometrique des coulis et par consequent sur leur capacite a injecter des colonnes de sable simulant un milieu fissure donne. La classe granulometrique d'un coulis, sa stabilite et sa fluidite sont apparus comme les trois facteurs principaux pour la reussite d'une injection. Un facteur de finesse a ete defini au cours de cette etude: base sur la classe granulometrique du ciment et sa stabilite, il peut entrer dans la formulation theorique du debit d'injection avant application sur chantier. La deuxieme et derniere partie de l'etude presente les resultats de deux projets de recherche sur l'injection realises sur chantier. L'injection de dalles de beton fissurees a permis le suivi de l'evolution des pressions avec la distance au point d'injection. L'injection de murs de maconnerie a caractere historique a montre l'importance de la definition de criteres de performance des coulis a utiliser pour traiter un milieu donne et pour un objectif donne. Plusieurs melanges peuvent ainsi etre predefinis et mis a disposition sur le chantier. La complementarite des ciments traditionnels et des ciments microfins devient alors un atout important. Le choix d'utilisation de ces melanges est fonction du terrain rencontre. En conclusion, cette recherche etablit une methodologie pour la selection des coulis a base de ciment et des pressions d'injection en fonction de l'ouverture des fissures ou joints de construction.

  13. 49 CFR 179.300-13 - Venting, loading and unloading valves.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Venting, loading and unloading valves. 179.300-13... Venting, loading and unloading valves. (a) Valves shall be of approved type, made of metal not subject to rapid deterioration by lading, and shall withstand tank test pressure without leakage. The valves...

  14. Vent for an electrochemical cell

    SciTech Connect

    Wilson, J.A.; Staniewicz, R.J.; Webber, B.; Allvey, G.W.

    1987-05-12

    A pressure relief vent is described for use with a container subjected to internal pressure by a fluid, the vent comprising: pressure relief means comprising a diaphragm essentially flat in shape fastened to the exterior of the container at the perimeter of the diaphragm and at a location within the perimeter of the diaphragm; an opening in the container disposed so that fluid from the container can pass between the diaphragm and the container and exert pressure on the diaphragm; and the pressure relief means being ruptured at a predetermined pressure exerted by the fluid on the diaphragm.

  15. Reactor pressure vessel vented head

    DOEpatents

    Sawabe, James K.

    1994-01-11

    A head for closing a nuclear reactor pressure vessel shell includes an arcuate dome having an integral head flange which includes a mating surface for sealingly mating with the shell upon assembly therewith. The head flange includes an internal passage extending therethrough with a first port being disposed on the head mating surface. A vent line includes a proximal end disposed in flow communication with the head internal passage, and a distal end disposed in flow communication with the inside of the dome for channeling a fluid therethrough. The vent line is fixedly joined to the dome and is carried therewith when the head is assembled to and disassembled from the shell.

  16. Modeling of zero gravity venting

    NASA Technical Reports Server (NTRS)

    Merte, H., Jr.

    1984-01-01

    The venting of cylindrical containers partially filled with initially saturated liquids was conducted under zero gravity conditions and compared with an analytical model which determined the effect of interfacial mass transfer on the ullage pressure response during venting. A model is proposed to improve the estimation of the interfacial mass transfer. Duhammel's superposition integral is incorporated in this analysis to approximate the transient temperature response of the interface, treating the liquid as a semiinfinite solid with conduction heat transfer. This approach to estimating interfacial mass transfer gives improved response when compared to previous models. The model still predicts a pressure decrease greater than those in the experiments reported.

  17. Location of seismic events and eruptive fissures on the Piton de la Fournaise volcano using seismic amplitudes

    USGS Publications Warehouse

    Battaglia, J.; Aki, K.

    2003-01-01

    We present a method for locating the source of seismic events on Piton de la Fournaise. The method is based on seismic amplitudes corrected for station site effects using coda site amplification factors. Once corrected, the spatial distribution of amplitudes shows smooth and simple contours for many types of events, including rockfalls, long-period events and eruption tremor. On the basis of the simplicity of these distributions we develop inversion methods for locating their origins. To achieve this, the decrease of the amplitude as a function of the distance to the source is approximated by the decay either of surface or body waves in a homogeneous medium. The method is effective for locating rockfalls, long-period events, and eruption tremor sources. The sources of eruption tremor are usually found to be located at shallow depth and close to the eruptive fissures. Because of this, our method is a useful tool for locating fissures at the beginning of eruptions.

  18. Diffuse versus discrete venting at the Tour Eiffel vent site, Lucky Strike hydrothermal field

    NASA Astrophysics Data System (ADS)

    Mittelstaedt, E. L.; Escartin, J.; Gracias, N.; Olive, J. L.; Barreyre, T.; Davaille, A. B.; Cannat, M.

    2010-12-01

    Two styles of fluid flow at the seafloor are widely recognized: (1) localized outflows of high temperature (>300°C) fluids, often black or grey color in color (“black smokers”) and (2) diffuse, lower temperature (<100°C), fluids typically transparent and which escape through fractures, porous rock, and sediment. The partitioning of heat flux between these two types of hydrothermal venting is debated and estimates of the proportion of heat carried by diffuse flow at ridge axes range from 20% to 90% of the total axial heat flux. Here, we attempt to improve estimates of this partitioning by carefully characterizing the heat fluxes carried by diffuse and discrete flows at a single vent site, Tour Eiffel in the Lucky Strike hydrothermal field along the Mid-Atlantic Ridge. Fluid temperature and video data were acquired during the recent Bathyluck’09 cruise to the Lucky Strike hydrothermal field (September, 2009) by Victor aboard “Pourquoi Pas?” (IFREMER, France). Temperature measurements were made of fluid exiting discrete vents, of diffuse effluents immediately above the seafloor, and of vertical temperature gradients within discrete hydrothermal plumes. Video data allow us to calculate the fluid velocity field associated with these outflows: for diffuse fluids, Diffuse Flow Velocimetry tracks the displacement of refractive index anomalies through time; for individual hydrothermal plumes, Particle Image Velocimetry tracks eddies by cross-correlation of pixels intensities between subsequent images. Diffuse fluids exhibit temperatures of 8-60°C and fluid velocities of ~1-10 cm s-1. Discrete outflows at 204-300°C have velocities of ~1-2 m s-1. Combined fluid flow velocities, temperature measurements, and full image mosaics of the actively venting areas are used to estimate heat flux of both individual discrete vents and diffuse outflow. The total integrated heat flux and the partitioning between diffuse and discrete venting at Tour Eiffel, and its

  19. The fissure: interlobar collateral ventilation and implications for endoscopic therapy in emphysema

    PubMed Central

    Koster, Theodoor David; Slebos, Dirk-Jan

    2016-01-01

    In patients with severe emphysema, bronchoscopic lung volume reduction using one-way valves is a promising therapeutic option to improve lung function and quality of life. The goal of this treatment is to achieve a complete lobar atelectasis. In a significant proportion of patients, this atelectasis cannot be achieved due to interlobar collateral ventilation. This collateral ventilation is generated through incomplete lobar fissures. Therefore, only patients with complete fissures and no collateral ventilation can be selected for endobronchial therapy with one-way valves. Incomplete fissures are very common and exhibit a great variation in anatomy. The reported prevalence is 17%–85% for the right major fissure, 19%–74% for the left major fissure, and 20%–90% for the minor fissure. There are several methods of measuring or predicting the presence of collateral ventilation, with computed tomography (CT)-fissure analysis and the Chartis measurement being the most important. CT-fissure analysis is an indirect method to measure the completeness of fissures as a surrogate for collateral ventilation. The Chartis system is an endobronchial method to directly measure the presence of collateral ventilation. Both methods have unique value, and the combination of both can accurately predict the treatment response to the bronchoscopic placement of endobronchial valves. This review provides an in-depth view of lung fissure and collateral ventilation to help understand its importance in selecting the appropriate patients for new emphysema treatments and thus avoid useless treatment in unsuitable patients. PMID:27110109

  20. A Review of Cyanoacrylate Liquid Skin Protectant and Its Efficacy on Pedal Fissures

    PubMed Central

    Vlahovic, Tracey C.; Hinton, Elizabeth A.; Chakravarthy, Debashish; Fleck, Cynthia Ann

    2011-01-01

    Introduction Skin fissures are a common dermatologic condition caused by excessive dry skin, numerous systemic diseases, and backless shoe gear. They are defects in skin that fall into the category of damaged, partial-thickness skin wounds, as opposed to full-thickness wounds. Patients with heel fissures are at an increased risk for developing infection, which could cause more severe issues, especially in patients with diabetes and peripheral vascular disease. Methods Five patients from Temple Foot and Ankle Institute, Philadelphia, PA, with a total of 8 heel fissures and 2 hallux fissures, were studied. Patients were dispensed 9 vials of a cyanoacrylate liquid skin protectant (Marathon™, Medline Industries, Inc, Mundelein, IL) to be applied to the fissure every 3 days. Patients returned every 2 weeks for follow-up in clinic. Results The hallux fissures and 4 of the heel fissures went to complete closure after 2 weeks. There was an average decrease of 1.16 cm in length of the heel fissure dimensions after 2 weeks and an average decrease of 1.1 cm in length of the hallux fissures. Conclusion This novel skin protectant proved to be a comfortable, easy, and effective tool in aiding the resolution of pedal skin fissures. PMID:24527155

  1. Wear of two pit and fissure sealants in contact with primary teeth

    PubMed Central

    Galo, Rodrigo; Contente, Marta Maria Martins Giamatei; Borsatto, Maria Cristina

    2014-01-01

    Objectives: Wear simulations may provide an indication of the clinical performance of pit-and-fissure sealants when associated with primary teeth as counterbody, restricting the involved variables. The aim of this study was to evaluate wear of dental materials used as pit-and-fissure sealants in contact with primary teeth. Materials and Methods: A resinous sealant (Fluroshield®) and a resin-modified glass ionomer cement (Vitremer®) were selected in a post-plate design, using as counterbody primary tooth pins (4 × 4 × 2 mm) at 3 and 10 N vertical load, 1 Hz frequency, 900 wear cycles in artificial saliva (n = 15). Attrition coefficient values were obtained and the material and primary tooth volumes were analyzed. Data were analyzed statistically by ANOVA and Duncan's test (P < 0.05). Results: Fluroshield® presented the highest attrition coefficient values for the 3 N but these values decreased significantly for the 10 N load. The means for volume loss (3 mm) of the different samples after the wear test were not statistically different for the materials. The volume loss values for the primary teeth were statistically different and there was an increase in volume loss with the increase of the load applied in the wear tests. Conclusions: Differences were also observed with regard to the surface deformation characteristics. The wear rates of primary tooth enamel vary according to the type of material and the load applied during mastication. PMID:24966777

  2. 33 CFR 159.61 - Vents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vents. 159.61 Section 159.61 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.61 Vents. Vents must be designed and...

  3. 33 CFR 159.61 - Vents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Vents. 159.61 Section 159.61 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.61 Vents. Vents must be designed and...

  4. 40 CFR Table 2 to Subpart G of... - Process Vents-Coefficients for Total Resource Effectiveness for New Source Nonhalogenated and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Process Vents-Coefficients for Total Resource Effectiveness for New Source Nonhalogenated and Halogenated Vent Streams 2 Table 2 to Subpart G of... Nonhalogenated and Halogenated Vent Streams Type of stream Control device basis Values of Coefficients a b c...

  5. 40 CFR Table 2 to Subpart G of... - Process Vents-Coefficients for Total Resource Effectiveness for New Source Nonhalogenated and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Process Vents-Coefficients for Total Resource Effectiveness for New Source Nonhalogenated and Halogenated Vent Streams 2 Table 2 to Subpart G of... Nonhalogenated and Halogenated Vent Streams Type of stream Control device basis Values of Coefficients a b c...

  6. 40 CFR Table 2 to Subpart G of... - Process Vents-Coefficients for Total Resource Effectiveness for New Source Nonhalogenated and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Process Vents-Coefficients for Total Resource Effectiveness for New Source Nonhalogenated and Halogenated Vent Streams 2 Table 2 to Subpart G of... Nonhalogenated and Halogenated Vent Streams Type of stream Control device basis Values of Coefficients a b c...

  7. EXPOSED BEAM AND VINYL VENTED SOFFIT MATERIAL IN THE CARPORT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXPOSED BEAM AND VINYL VENTED SOFFIT MATERIAL IN THE CARPORT ON THE SOUTHEAST SIDE OF THE UNIT - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

  8. Assessing the atmospheric and climatic effects of basaltic fissure eruptions. A case study Nornahraun, North Iceland, 2014-2015.

    NASA Astrophysics Data System (ADS)

    Gallagher, Catherine; Burton, Kevin; Thordarson, Thorvaldur; Vye-Brown, Charlotte; Brown, Richard

    2015-04-01

    A volcanic eruption's ability to release sulphur gases into the atmosphere is one of the critical factors in assessing their climatic and environmental effects, because it is directly linked to the potential H2SO4 aerosol burden produced [1]. Basaltic fissure eruptions loft large amounts of sulphur into the atmosphere because of the efficient degassing of volatiles and halogens from the magma at the vent [2-4] coupled with the high sulphur yield of basaltic magma. The common nature of this style of eruption and its products, regardless of magnitude, means that our understanding of the exact processes which influence atmospheric chemistry and environmental impact is very important. The Nornahraun fissure eruption in North Iceland that began on the 31st August 2014, has quickly become one of the best documented eruptions of its kind, through systematic monitoring and sampling by the Institute of Earth Sciences eruption team and The Icelandic Meteorological Office. As a result it is an excellent modern analogue for historic or ancient basaltic fissure eruptions, for which the amount of degassing can only be estimated through petrological and geochemical methods. It also serves as a timely testing platform for novel geochemical proxies. This study uses the exceptional sensitivity of the 187Os-187Re radiogenic system to the presence of crustal material [5], and highly siderophile stable isotopes Cu, Zn and S to indicate the chemistry and degassing of the melt carrying S to the surface. The geochemical isotopic proxies will be tested using established petrological methods and gas emission data. This study concentrates on determining the following key parameters: (1) The source of volatiles in the magma indicated though the pressure dependence of S solubility. (2) The mechanism of aerosol and gas release into the atmosphere is dictated both by the chemistry of the melt that controls the S species (H2S, SO2 or FeS2) present [6], and by the mechanism of transfer. (3) The

  9. Enamel fusion using a carbon dioxide laser: A technique for sealing pits and fissures

    SciTech Connect

    Walsh, L.J.; Perham, S.J. )

    1991-05-01

    The well-established enhanced resistance of lased enamel to demineralization is the basis for clinical application of the carbon dioxide laser to caries prevention. This in vitro study examined the effect of focused infrared laser radiation on sound enamel and early pit and fissure caries. Low power levels (2-5 W) induced localized melting and resolidification of enamel with little surface destruction. For sound fissures, fusion of enamel from the lateral walls of the fissure eliminated the fissure space, providing a sealant effect; while in carious fissures, carious enamel was vaporized and adjacent sound enamel fused to partially eliminate the defect. The technique for enamel fusion using CO2 lasers has potential application for sealing pits and fissures and producing physicochemical alterations in enamel which may have preventive benefits.

  10. Cellular resolution optical access to brain regions in fissures: Imaging medial prefrontal cortex and grid cells in entorhinal cortex

    PubMed Central

    Low, Ryan J.; Gu, Yi; Tank, David W.

    2014-01-01

    In vivo two-photon microscopy provides the foundation for an array of powerful techniques for optically measuring and perturbing neural circuits. However, challenging tissue properties and geometry have prevented high-resolution optical access to regions situated within deep fissures. These regions include the medial prefrontal and medial entorhinal cortex (mPFC and MEC), which are of broad scientific and clinical interest. Here, we present a method for in vivo, subcellular resolution optical access to the mPFC and MEC using microprisms inserted into the fissures. We chronically imaged the mPFC and MEC in mice running on a spherical treadmill, using two-photon laser-scanning microscopy and genetically encoded calcium indicators to measure network activity. In the MEC, we imaged grid cells, a widely studied cell type essential to memory and spatial information processing. These cells exhibited spatially modulated activity during navigation in a virtual reality environment. This method should be extendable to other brain regions situated within deep fissures, and opens up these regions for study at cellular resolution in behaving animals using a rapidly expanding palette of optical tools for perturbing and measuring network structure and function. PMID:25503366

  11. Joints, fissures, and voids in rhyolite welded ash-flow tuff at Teton damsite, Idaho

    USGS Publications Warehouse

    Prostka, Harold J.

    1977-01-01

    Several kinds of joints, fissures, and voids are present in densely welded rhyolite ash-flow tuff at Teton damsite. Older fissures and voids probably were formed in the ash-flow sheet during secondary flowage, which probably was caused by differential compaction or settling over irregular topography. The younger, more abundant fissures are mostly steep cooling joints that probably have been opened farther by horizontal tectonic extension and gravitational creep, perhaps aided by lateral stress relief.

  12. Surface anatomy of the pulmonary fissures determined by high-resolution computed tomography.

    PubMed

    Heřmanová, Zuzana; Ctvrtlík, Filip; Heřman, Miroslav

    2012-10-01

    The aim of our study was to describe the surface anatomy of the interlobar fissures using volumetric thin-section high-resolution computed tomography (HRCT). Retrospective assessment of HRCT examinations of 250 patients was performed. The localization of the oblique fissures was marked at three sites: posteriorly at its most superior medial limit, laterally in the midaxillary line, and inferiorly at the junction of the middle and lateral thirds of the hemithorax; posteriorly and laterally, this was to the nearest rib whilst inferiorly the position was described in relation to the diaphragm or chest wall. The localization of the horizontal fissure was marked anteriorly in relation to the nearest rib (or costal cartilage) and posteriorly where it intersected with the oblique fissure (superior, middle, or inferior third). Shapes of the fissures and differences between inspiration and expiration were also documented. Descriptive statistics were used to report the most frequent positions. The most frequent localization of the oblique fissure on the left side was posteriorly at the fourth rib (45%), laterally at the sixth rib (52%), and inferiorly in the anterior third of the hemidiaphragm (60%). The right oblique fissure was located posteriorly at the fifth rib (50%), laterally at the sixth rib (50%), and inferiorly in the anterior third of the hemidiaphragm (71%). The horizontal fissure most commonly originated in the middle third of the oblique fissure (61%) and met the anterior thoracic wall at the level of the fourth rib (51%). The most frequent shape of the left oblique fissure was linear (78%), whereas S-shaped and linear configurations (28% each) were most frequent on the right. No difference was found in the surface markings of the fissures between inspiration and expiration in 90% of cases. The considerable individual variation in the position and shape of the interlobar fissures helps to explain the variable descriptions of their surface anatomy in the

  13. Space shuttle orbiter venting: Lessons learned

    NASA Technical Reports Server (NTRS)

    Lutfi, H. S.; Nieder, R. L.

    1983-01-01

    The orbiter vent system provides dedicated vent areas to permit the gases trapped inside the vehicle to escape during accent. The same vent system also repressurizes the vehicle during entry. The vent system is one of six systems that constitutes the purge, vent and drain subsystem. The orbiter active vent system has been very adaptable to the changing requirements that have occurred during the development of the Space Shuttle orbiter. Good correlation has been obtained between predicted and measured compartment pressures during the orbital flight test (OFT) program. An investigation of the flight data showed that the difference between preflight prediction and the measured values were primarily due to the difference between the baseline external pressures, which was based on subscale wind tunnel test data, and the actual vehicle local external pressures measured during the flight. The current predictions are based on flight derived vent port pressure coefficients since the wind tunnel data does not adequately define the orbiter ascent pressure environment.

  14. Clinical analysis of molar fissures by Cone-beam tomography.

    PubMed

    Cruvinel, V R N; Azevedo, B C; Gravina, D B L; Toledo, O A; Bezerra, A C B

    2007-01-01

    This study aimed to validate clinical analysis of 20 pediatric dentists on occlusal groove-fossa-system of molar depth comparing to Cone-beam tomography. The 48 sound third molars were visually classified from the shallowest to the deepest. Images were taken from the Accuitomo 3DX. There was a fair correlation between clinical analysis and the tomographic scorings (rs = 0.238; P = 0.103). It was concluded that pediatric dentists were not able to classify the fissures depth by visual analysis correctly. PMID:19161057

  15. Fluoride release and uptake abilities of different fissure sealants

    PubMed Central

    Andenna, Gianluigi; Ceci, Matteo; Beltrami, Riccardo; Colombo, Marco; Cucca, Lucia

    2016-01-01

    Background The long-term capability of resin sealants and glass ionomer cements to release fluoride is associated to a reduction in pit and fissure caries. The regular use of fluoride varnishes/toothpastes can result in the absorption of fluoride into the sealant. The objective of the present study was to assess the fluoride release/uptake capacities of different fissure sealants. Material and Methods Three different fissure sealants (Fuji Triage/GC, Fissurit FX/Voco and Grandio Seal/Voco) were examined. Ten discs of each material were prepared. Each disc was incubated with distilled water and then the solution analyzed for diluted for fluoride concentration, using a combination of fluoride electrode (OrionGP 1 S/N 13824, Orion Research Inc, Boston, MA, USA) connected to an expandable ion analyzer (Orion 720A, Orion Research Inc, Boston, MA, USA). Standard curves between 1 and 100 ppm F- were used to calibrate the electrode. Cumulative fluoride release was measured on days 1, 2, 3, 5, 7, 21, 35 and 49, then two different fluoride varnishes/pastes (Profluorid Varnish/Voco, MI Paste Plus/GC), were applied to the sealants tested, and fluoride release (after reuptake) was measured on days 56, 70 and 84. Results Kruskal Wallis test confirmed significant differences in fluoride release between Fuji Triage/GC and Fissurit FX/Voco and Grandio Seal/Voco from day 1 (P < 0.001). The application of fluoride varnish Profluorid Varnish enhanced the fluoride release for all sealants (P < 0.05). MI Paste Plus enhanced the fluoride release for all sealants except for Fuji Triage/GC (P > 0.05). Conclusions The GIC-based sealant (Fuji Triage/GC) released significantly more fluoride than the resin sealants tested. The exposure to the fluoridated varnish (Profluorid Varnish) significantly recharged the sealants tested more than the CPP-ACPF toothpaste (MI Paste Plus). Key words:Fissure sealants, fluoride release, fluoride uptake, glass ionomer cements. PMID:27398179

  16. A rare case of myeloid sarcoma presenting as anal fissure

    PubMed Central

    VECCHIO, R.; INTAGLIATA, E.; FIUMARA, P.F.; VILLARI, L.; MARCHESE, S.; CACCIOLA, E.

    2015-01-01

    Myeloid sarcoma is a tumor composed of myeloblasts occurring at an extramedullary site. It may develop in patients with acute myeloid leukemia, myeloproliferative or myelodysplastic syndrome, sometimes preceding onset of the systemic disease. Frequent sites of myeloid sarcoma are bones or various soft tissues. Gastrointestinal involvement is very rare. We report a unique case of myeloid sarcoma presenting as a painful anal fissure, in a patient with a history of acute myeloid leukemia. The diagnosis was achieved by a surgical excisional biopsy and immunoistochemical staining. PMID:26712260

  17. Automatic pulmonary fissure detection and lobe segmentation in CT chest images

    PubMed Central

    2014-01-01

    Background Multi-detector Computed Tomography has become an invaluable tool for the diagnosis of chronic respiratory diseases. Based on CT images, the automatic algorithm to detect the fissures and divide the lung into five lobes will help regionally quantify, amongst others, the lung density, texture, airway and, blood vessel structures, ventilation and perfusion. Methods Sagittal adaptive fissure scanning based on the sparseness of the vessels and bronchi is employed to localize the potential fissure region. Following a Hessian matrix based line enhancement filter in the coronal slice, the shortest path is determined by means of Uniform Cost Search. Implicit surface fitting based on Radial Basis Functions is used to extract the fissure surface for lobe segmentation. By three implicit fissure surface functions, the lung is divided into five lobes. The proposed algorithm is tested by 14 datasets. The accuracy is evaluated by the mean (±S.D.), root mean square, and the maximum of the shortest Euclidian distance from the manually-defined fissure surface to that extracted by the algorithm. Results Averaged over all datasets, the mean (±S.D.), root mean square, and the maximum of the shortest Euclidian distance are 2.05 ± 1.80, 2.46 and 7.34 mm for the right oblique fissure. The measures are 2.77 ± 2.12, 3.13 and 7.75 mm for the right horizontal fissure, 2.31 ± 1.76, 3.25 and 6.83 mm for the left oblique fissure. The fissure detection works for the data with a small lung nodule nearby the fissure and a small lung subpleural nodule. The volume and emphysema index of each lobe can be calculated. The algorithm is very fast, e.g., to finish the fissure detection and fissure extension for the dataset with 320 slices only takes around 50 seconds. Conclusions The sagittal adaptive fissure scanning can localize the potential fissure regions quickly. After the potential region is enhanced by a Hessian based line enhancement filter, Uniform Cost Search can

  18. Differences in recovery between deep-sea hydrothermal vent and vent-proximate communities after a volcanic eruption

    NASA Astrophysics Data System (ADS)

    Gollner, Sabine; Govenar, Breea; Arbizu, Pedro Martinez; Mills, Susan; Le Bris, Nadine; Weinbauer, Markus; Shank, Timothy M.; Bright, Monika

    2015-12-01

    Deep-sea hydrothermal vents and the surrounding basalt seafloor are subject to major natural disturbance events such as volcanic eruptions. In the near future, anthropogenic disturbance in the form of deep-sea mining could also significantly affect the faunal communities of hydrothermal vents. In this study, we monitor and compare the recovery of insular, highly productive vent communities and vent-proximate basalt communities following a volcanic eruption that destroyed almost all existing communities at the East Pacific Rise, 9°50‧N in 2006. To study the recovery patterns of the benthic communities, we placed settlement substrates at vent sites and their proximate basalt areas and measured the prokaryotic abundance and compared the meio- and macrofaunal species richness and composition at one, two and four years after the eruption. In addition, we collected samples from the overlying water column with a pelagic pump, at one and two years after the volcanic eruption, to determine the abundance of potential meiofauna colonisers. One year after eruption, mean meio- and macrofaunal abundances were not significantly different from pre-eruption values in vent habitats (meio: 8-1838 ind. 64 cm-2 in 2006; 3-6246 ind. 64 cm-2 in 2001/02; macro: 95-1600 ind. 64 cm-2 in 2006; 205-4577 ind. 64 cm-2 in 2001/02) and on non-vent basalt habitats (meio: 10-1922 ind. 64 cm-2 in 2006; 8-328 ind. 64 cm-2 in 2003/04; macro: 14-3351 ind. 64 cm-2 in 2006; 2-63 ind. 64 cm-2 in 2003/04), but species recovery patterns differed between the two habitat types. In the vent habitat, the initial community recovery was relatively quick but incomplete four years after eruption, which may be due to the good dispersal capabilities of vent endemic macrofauna and vent endemic dirivultid copepods. At vents, 42% of the pre-eruption meio- and 39% of macrofaunal species had returned. In addition, some new species not evident prior to the eruption were found. At the tubeworm site Tica, a total of 26

  19. Tectonic and magmatic controls on the location of post-subduction monogenetic volcanoes in Baja California, Mexico, revealed through spatial analysis of eruptive vents

    NASA Astrophysics Data System (ADS)

    Germa, Aurélie; Connor, Laura J.; Cañon-Tapia, Edgardo; Le Corvec, Nicolas

    2013-12-01

    Post-subduction (12.5 Ma to less than 1 Ma) monogenetic volcanism on the Baja California peninsula, Mexico, formed one of the densest intra-continental areas of eruptive vents on Earth. It includes about 900 vents within an area ˜700 km long (N-S) and 70 to 150 km wide (W-E). This study shows that post-subduction volcanic activity was distributed along this arc and that modes exist in the volcano distribution, indicating that productivity of the magma source region was not uniform along the length of the arc. Vent clustering, vent alignments, and cone elongations were measured within eight monogenetic volcanic fields located along the peninsula. Results indicate that on a regional scale, vent clustering varies from north to south with denser spatial clustering in the north on the order of 1.9 × 10-1 vents/km2 to less dense clustering in the south on the order of 7.8 × 10-2 vents/km2. San Quintin, San Carlos, Jaraguay, and Santa Clara are spatially distinct volcanic fields with higher eruptive vent densities suggesting the existence of individual melt columns that may have persisted over time. In contrast, the San Borja, Vizcaino, San Ignacio, and La Purisima vent fields show lower degrees of vent clustering and no obvious spatial gaps between fields, thus indicating an area of more distributed volcanism. Insight into the lithospheric stress field can be gained from vent alignments and vent elongation measurements. Within the fields located along the extinct, subduction-related volcanic arc, elongation patterns of cinder cones and fissure-fed spatter cones, vent clusters, and vent alignments trend NW-SE and N-S. Within the Santa Clara field, located more to the west within the forearc, elongation patterns of the same volcanic features trend NE-SW. These patterns suggest that magmatism was more focused in the forearc and in the northern part of Baja California than in its southern region. Within the extinct arc, magma ascent created volcano alignments and elongate

  20. Endemic hydrothermal vent species identified in the open ocean seed bank.

    PubMed

    Gonnella, Giorgio; Böhnke, Stefanie; Indenbirken, Daniela; Garbe-Schönberg, Dieter; Seifert, Richard; Mertens, Christian; Kurtz, Stefan; Perner, Mirjam

    2016-01-01

    Hydrothermal vent systems host microbial communities among which several microorganisms have been considered endemic to this type of habitat. It is still unclear how these organisms colonize geographically distant hydrothermal environments. Based on 16S rRNA gene sequences, we compare the bacterial communities of sixteen Atlantic hydrothermal vent samples with our own and publicly available global open ocean samples. Analysing sequences obtained from 63 million 16S rRNA genes, the genera we could identify in the open ocean waters contained 99.9% of the vent reads. This suggests that previously observed vent exclusiveness is, in most cases, probably an artefact of lower sequencing depth. These findings are a further step towards elucidating the role of the open ocean as a seed bank. They can explain the predicament of how species expected to be endemic to vent systems are able to colonize geographically distant hydrothermal habitats and contribute to our understanding of whether 'everything is really everywhere'. PMID:27573109

  1. Evidence for a Chemoautotrophically Based Food Web at Inactive Hydrothermal Vents (Manus Basin)

    NASA Astrophysics Data System (ADS)

    van Dover, C. L.; Erickson, K.; Macko, S.

    2008-12-01

    Hydrothermal vents are ephemeral systems. When venting shuts down, sulfide-dependent taxa die off, and non-vent taxa can colonize the hard substrata. In Manus Basin (Papua New Guinea), where active and inactive sulfide mounds are interspersed, hydroids, cladorhizid sponges, barnacles, and bamboo sponges, and other invertebrate types may occupy inactive sulfide mounds. Carbon and nitrogen isotopic compositions of animals occupying inactive sulfide mounds are consistent with nutritional dependence on either chemoautotrophically or photosynthetically produced organic material, but sulfur isotopic compositions of these animals point to a chemoautotrophic source of sulfur from dissolved sulfide in vent fluids rather than sulfur derived from seawater sulfate through photosynthesis. Given that suspension-feeding and micro- carnivorous invertebrates are the biomass dominants at inactive sulfide mounds, the primary source of chemoautotrophic nutrition is likely suspended particulates and organisms delivered from nearby active vents.

  2. Evidence for a chemoautotrophically based food web at inactive hydrothermal vents (Manus Basin)

    NASA Astrophysics Data System (ADS)

    Erickson, K. L.; Macko, S. A.; Van Dover, C. L.

    2009-09-01

    Hydrothermal vents are ephemeral systems. When venting shuts down, sulfide-dependent taxa die off, and non-vent taxa can colonize the hard substrata. In Manus Basin (Papua New Guinea), where hydrothermally active and inactive sites are interspersed, hydroids, cladorhizid sponges, barnacles, bamboo corals, and other invertebrate types may occupy inactive sites. Carbon and nitrogen isotopic compositions of animals occupying inactive sites are consistent with nutritional dependence on either chemoautotrophically or photosynthetically produced organic material, but sulfur isotopic compositions of these animals point to a chemoautotrophic source of sulfur from dissolved sulfide in vent fluids rather than sulfur derived from seawater sulfate through photosynthesis. Given that suspension-feeding and micro-carnivorous invertebrates are the biomass dominants at inactive sites, the primary source of chemoautotrophic nutrition is likely suspended particulates and organisms delivered from nearby active vents.

  3. Endemic hydrothermal vent species identified in the open ocean seed bank.

    PubMed

    Gonnella, Giorgio; Böhnke, Stefanie; Indenbirken, Daniela; Garbe-Schönberg, Dieter; Seifert, Richard; Mertens, Christian; Kurtz, Stefan; Perner, Mirjam

    2016-06-13

    Hydrothermal vent systems host microbial communities among which several microorganisms have been considered endemic to this type of habitat. It is still unclear how these organisms colonize geographically distant hydrothermal environments. Based on 16S rRNA gene sequences, we compare the bacterial communities of sixteen Atlantic hydrothermal vent samples with our own and publicly available global open ocean samples. Analysing sequences obtained from 63 million 16S rRNA genes, the genera we could identify in the open ocean waters contained 99.9% of the vent reads. This suggests that previously observed vent exclusiveness is, in most cases, probably an artefact of lower sequencing depth. These findings are a further step towards elucidating the role of the open ocean as a seed bank. They can explain the predicament of how species expected to be endemic to vent systems are able to colonize geographically distant hydrothermal habitats and contribute to our understanding of whether 'everything is really everywhere'.

  4. Reactor pressure vessel vented head

    DOEpatents

    Sawabe, J.K.

    1994-01-11

    A head for closing a nuclear reactor pressure vessel shell includes an arcuate dome having an integral head flange which includes a mating surface for sealingly mating with the shell upon assembly therewith. The head flange includes an internal passage extending therethrough with a first port being disposed on the head mating surface. A vent line includes a proximal end disposed in flow communication with the head internal passage, and a distal end disposed in flow communication with the inside of the dome for channeling a fluid therethrough. The vent line is fixedly joined to the dome and is carried therewith when the head is assembled to and disassembled from the shell. 6 figures.

  5. Comparative study of vent and seep macrofaunal communities in the Guaymas Basin

    NASA Astrophysics Data System (ADS)

    Portail, M.; Olu, K.; Escobar-Briones, E.; Caprais, J. C.; Menot, L.; Waeles, M.; Cruaud, P.; Sarradin, P. M.; Godfroy, A.; Sarrazin, J.

    2015-09-01

    Understanding the ecological processes and connectivity of chemosynthetic deep-sea ecosystems requires comparative studies. In the Guaymas Basin (Gulf of California, Mexico), the presence of seeps and vents in the absence of a biogeographic barrier, and comparable sedimentary settings and depths offers a unique opportunity to assess the role of ecosystem-specific environmental conditions on macrofaunal communities. Six seep and four vent assemblages were studied, three of which were characterised by common major foundation taxa: vesicomyid bivalves, siboglinid tubeworms and microbial mats. Macrofaunal community structure at the family level showed that density, diversity and composition patterns were primarily shaped by seep- and vent-common abiotic factors including methane and hydrogen sulfide concentrations, whereas vent environmental specificities (higher temperature, higher metal concentrations and lower pH) were not significant. The type of substratum and the heterogeneity provided by foundation species were identified as additional structuring factors and their roles were found to vary according to fluid regimes. At the family level, seep and vent similarity reached at least 58 %. All vent families were found at seeps and each seep-specific family displayed low relative abundances (< 5 %). Moreover, 85 % of the identified species among dominant families were shared between seep and vent ecosystems. This study provides further support to the hypothesis of continuity among deep-sea seep and vent ecosystems.

  6. Fissure sealants: Knowledge and practice of Yemeni dental practitioners

    PubMed Central

    Al-Maweri, Sadeq Ali; Al-Jamaei, Aisha Ahmed; Halboub, Esam Saleh; Al-Soneidar, Walid Ahmed; Tarakji, Bassel; Alsalhani, Anas

    2016-01-01

    Objectives This study was conducted to evaluate Yemeni dental practitioners' knowledge and practices concerning fissure sealants. Materials and Methods: A modified questionnaire consisted of 25-items was distributed to 500 dentists working in Sana'a City. Descriptive statistics and Chi-square/Fisher's exact tests were used for statistical analyses. Results: The response rate was 74%. Most of the respondents were male (61.3%), general practitioners (84.2%), and had <5 years of clinical experience (48.3%). The respondents showed a reasonable level of knowledge about sealants, with the majority (88%) believed that there is strong scientific evidence about fissure sealants effectiveness and around 90% showed a good understanding of sealant placement instructions. On the other hand, respondents showed insufficient knowledge about sealants clinical practice. Conclusion: Although a high proportion of dental practitioners showed adequate knowledge about dental sealant, following guidelines and standardized procedures in clinical practice is lacking. These emphasize the need for regular continuing education courses for dental professional. PMID:27095903

  7. The effect of normal pulsed Nd-YAG laser irradiation on pits and fissures in human teeth.

    PubMed

    Bahar, A; Tagomori, S

    1994-01-01

    The effects of normal pulsed Nd-YAG laser irradiation on the acid resistance of human dental enamel of pits and fissures, the cleaning of the pit and fissure contents and fluoride uptake into deep pits and fissures were examined. The acid resistance of the pit and fissure enamel was evaluated by the amount of dissolved calcium per square millimeter of the surface area. The pit and fissure enamel treated with laser irradiation obtained an acid resistance 30% higher than that of the unlased controls. The cleaning effect of laser irradiation on the pit and fissure contents was compared with chemicomechanical and mechanical methods. The laser irradiation was found to clean the pits and fissures to a greater depth without alterating the shape of pits and fissures, compared with the other two methods. The distribution of calcium, phosphorus and fluoride in the enamel of the pits and fissures was then measured by electron probe microanalyzer. At the entrance and in the deep part of the pits and fissures, the fluoride content of the enamel treated with acidulated phosphate fluoride after laser irradiation was higher than that of the enamel treated with acidulated phosphate fluoride alone. These results thus suggest that Nd-YAG laser irradiation might be effective in increasing the acid resistance of the pit and fissure enamel, while removing the pit and fissure debris contents and increasing the fluoride uptake into the pit and fissure enamel.

  8. Fracture mechanical behavior of red sandstone containing a single fissure and two parallel fissures after exposure to different high temperature treatments

    NASA Astrophysics Data System (ADS)

    Yang, Sheng-Qi; Jing, Hong-Wen; Huang, Yan-Hua; Ranjith, P. G.; Jiao, Yu-Yong

    2014-12-01

    A detailed understanding of the brittle deformation behavior of sandstone containing pre-existing flaws at elevated temperatures is a key concern in underground engineering. In this research, uniaxial compression tests were performed to evaluate the effect of high temperature treatments (300, 600 or 900 °C) on the strength, deformability and fracture coalescence behavior of a sandstone containing either a single fissure or two parallel fissures. All experiments focused on rectangular prismatic (80 × 160 × 30 mm) specimens of red sandstone. Constant strain rate experiments were performed on either: (1) specimens that contained a single 2 mm-wide fissure or (2) specimens that contained two 2 mm-wide parallel fissures. The specimens containing either one or two fissures were either left at room temperature (i.e., no heat treatment), or heat treated to 300, 600 or 900 °C prior to experimentation. The results demonstrated that, in all cases, the strength and stiffness of red sandstone was increased at 300 °C, before decreasing up to our maximum temperature of 900 °C. However, the peak strain at failure always showed an increase when the temperature was increased. The crack initiation, propagation and coalescence process were monitored during the deformation using both photographic monitoring and acoustic emission (AE) monitoring techniques. The monitoring results showed that the cracking process depended on both the fissure geometry and the heat treatment temperature. The potential mechanisms causing the differences in the mechanical behavior observed with increasing temperature are discussed, as is the influence of the single fissure and the two parallel fissures on the crack evolution process. These results are important and valuable to understand the fracture mechanism of rock engineering in deep underground mining excavations and nuclear waste depositories.

  9. Preserving rice quality: fine mapping and introgressing a fissure resistance locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice (Oryza sativa L.) kernel fissuring is a major concern of both rice producers and millers. Fissures are small cracks in the rice kernels that increase the percentage of breakage among the kernels when they are transported and milled, which decreases the value of processed rice. This study employ...

  10. Baghdad Suchus on Enceladus: Constraints on the Temperature and Width at the Fissure Mouth

    NASA Astrophysics Data System (ADS)

    Goguen, Jay D.; Buratti, B. J.; Brown, R. H.; Clark, R. N.; Nicholson, P. D.; Hedman, M. M.; Sotin, C.; Cruikshank, D. P.; Baines, K. H.

    2013-10-01

    A Cassini VIMS spectrum of an active location along Baghdad Sulchus is best fit by a fissure 9 m wide at T=197 K (Goguen et al. 2013, Icarus, accepted). We show that narrower and hotter fissures are unstable due to the exponential increase of the vapor pressure of ice for T greater than 200 K. Ice at 230 K will erode 1 meter/day due to sublimation, so a narrower and warmer fissure will quickly erode to meter widths. The same strong T dependence of the vapor pressure also means that wider fissures at T ~180 K cannot supply to total mass loss rate constraint from Cassini UVIS occultation data. The mass loss rate can be supplied if a significant fraction 190 km) of the total length of the fissures is active as a 9 m wide fissure with T=197 K. The contribution of this hottest component of the fissure emission contributes only a small fraction of the total observed radiated power from the fissures which is dominated by much larger areas at lower T and is best characterized using the CIRS instrument. Copyright 2013 California Institute of Technology.

  11. 21 CFR 872.3765 - Pit and fissure sealant and conditioner.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pit and fissure sealant and conditioner. 872.3765 Section 872.3765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3765 Pit and fissure sealant...

  12. 21 CFR 872.3765 - Pit and fissure sealant and conditioner.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pit and fissure sealant and conditioner. 872.3765 Section 872.3765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3765 Pit and fissure sealant...

  13. Holocene intracontinental deformation of the northern North China Plain: Evidence of tectonic ground fissures

    NASA Astrophysics Data System (ADS)

    Xu, Liqing; Li, Sanzhong; Cao, Xianzhi; Somerville, I. D.; Suo, Yanhui; Liu, Xin; Dai, Liming; Zhao, Shujuan; Guo, Lingli; Wang, Pengcheng; Cao, Huahua

    2016-04-01

    Following the collecting and analyzing of field data on the geometry and kinematics characteristics of ground fissures in the northern North China Plain (NNCP), this paper shows that en échelon ground fissures or tectonic ground fissures with a length of several meters to tens of kilometers extending along active faults are possibly controlled by underlying active faults. There are two groups of tectonic ground fissures developed in the NNCP. One group consists of ENE-trending "right-stepping" ground fissures, some of which have a component of sinistral motion. The other group is NNE-trending "left-stepping" ground fissures with dextral motion. A large amount of data from trenches, boreholes and seismic exploration reflect that they are active-faulting-related. The NNW-trending regional extensional stress field and the reactivation of pre-existing faults are the major factors controlling ground fissures. Data from the Quaternary sedimentary records, deep incised valleys, the distribution of earthquakes and ground fissures, and our field work show that the Holocene intracontinental deformation of the NNCP is characterized by intense faulting and northwestward tilting, which may be related to a NNW-SSE-oriented tensional stress field in the shallow crust and asthenospheric upwelling in the mantle.

  14. Mineralization of Alvinella polychaete tubes at hydrothermal vents

    PubMed Central

    Georgieva, M N; Little, C T S; Ball, A D; Glover, A G

    2015-01-01

    Alvinellid polychaete worms form multilayered organic tubes in the hottest and most rapidly growing areas of deep-sea hydrothermal vent chimneys. Over short periods of time, these tubes can become entirely mineralized within this environment. Documenting the nature of this process in terms of the stages of mineralization, as well as the mineral textures and end products that result, is essential for our understanding of the fossilization of polychaetes at hydrothermal vents. Here, we report in detail the full mineralization of Alvinella spp. tubes collected from the East Pacific Rise, determined through the use of a wide range of imaging and analytical techniques. We propose a new model for tube mineralization, whereby mineralization begins as templating of tube layer and sublayer surfaces and results in fully mineralized tubes comprised of multiple concentric, colloform, pyrite bands. Silica appeared to preserve organic tube layers in some samples. Fine-scale features such as protein fibres, extracellular polymeric substances and two types of filamentous microbial colonies were also found to be well preserved within a subset of the tubes. The fully mineralized Alvinella spp. tubes do not closely resemble known ancient hydrothermal vent tube fossils, corroborating molecular evidence suggesting that the alvinellids are a relatively recent polychaete lineage. We also compare pyrite and silica preservation of organic tissues within hydrothermal vents to soft tissue preservation in sediments and hot springs. PMID:25556400

  15. Mineralization of Alvinella polychaete tubes at hydrothermal vents.

    PubMed

    Georgieva, M N; Little, C T S; Ball, A D; Glover, A G

    2015-03-01

    Alvinellid polychaete worms form multilayered organic tubes in the hottest and most rapidly growing areas of deep-sea hydrothermal vent chimneys. Over short periods of time, these tubes can become entirely mineralized within this environment. Documenting the nature of this process in terms of the stages of mineralization, as well as the mineral textures and end products that result, is essential for our understanding of the fossilization of polychaetes at hydrothermal vents. Here, we report in detail the full mineralization of Alvinella spp. tubes collected from the East Pacific Rise, determined through the use of a wide range of imaging and analytical techniques. We propose a new model for tube mineralization, whereby mineralization begins as templating of tube layer and sublayer surfaces and results in fully mineralized tubes comprised of multiple concentric, colloform, pyrite bands. Silica appeared to preserve organic tube layers in some samples. Fine-scale features such as protein fibres, extracellular polymeric substances and two types of filamentous microbial colonies were also found to be well preserved within a subset of the tubes. The fully mineralized Alvinella spp. tubes do not closely resemble known ancient hydrothermal vent tube fossils, corroborating molecular evidence suggesting that the alvinellids are a relatively recent polychaete lineage. We also compare pyrite and silica preservation of organic tissues within hydrothermal vents to soft tissue preservation in sediments and hot springs. PMID:25556400

  16. Mineralization of Alvinella polychaete tubes at hydrothermal vents.

    PubMed

    Georgieva, M N; Little, C T S; Ball, A D; Glover, A G

    2015-03-01

    Alvinellid polychaete worms form multilayered organic tubes in the hottest and most rapidly growing areas of deep-sea hydrothermal vent chimneys. Over short periods of time, these tubes can become entirely mineralized within this environment. Documenting the nature of this process in terms of the stages of mineralization, as well as the mineral textures and end products that result, is essential for our understanding of the fossilization of polychaetes at hydrothermal vents. Here, we report in detail the full mineralization of Alvinella spp. tubes collected from the East Pacific Rise, determined through the use of a wide range of imaging and analytical techniques. We propose a new model for tube mineralization, whereby mineralization begins as templating of tube layer and sublayer surfaces and results in fully mineralized tubes comprised of multiple concentric, colloform, pyrite bands. Silica appeared to preserve organic tube layers in some samples. Fine-scale features such as protein fibres, extracellular polymeric substances and two types of filamentous microbial colonies were also found to be well preserved within a subset of the tubes. The fully mineralized Alvinella spp. tubes do not closely resemble known ancient hydrothermal vent tube fossils, corroborating molecular evidence suggesting that the alvinellids are a relatively recent polychaete lineage. We also compare pyrite and silica preservation of organic tissues within hydrothermal vents to soft tissue preservation in sediments and hot springs.

  17. Relative air permeability as function of saturation in soil venting

    SciTech Connect

    Stylianou, C.; DeVantier, B.A.

    1995-04-01

    Traditionally, soil remediation involved soil flushing, or excavation followed by landfilling or treatment. In recent years, recognizing the major environmental problem of soil contamination by VOCs, soil vapor extraction (SVE, also known as soil venting) has been applied as a form of in situ remediation. A key parameter in modeling soil-venting systems is relative air permeability, determined as a function of liquid saturation. The focus of the present study was to characterize the relationship of the relative air permeability as a function of air saturation in soil-venting systems. A new laboratory apparatus was used to simulate the soil venting and measure the air permeability of soil samples. Sand samples wetted with mixtures of water and gasoline at different ratios were used. It was revealed that the prediction of relative air permeability for moist noncohesive soil can be made in terms of intrinsic permeability and air-filled porosity alone, and not the type of liquid present in the pores. Comparisons of measured data with existing relations for relative air permeability as a function of total liquid saturation were made to determine the most accurate and practical forms for engineering applications. For the sand sample used, the evaluation revealed that compared to the existing relations, a derived second-order polynomial expression provides a good estimate of relative air permeability and does not require estimation of soil-water-retention curve parameters.

  18. Explosive Volcanic Eruptions from Linear Vents on Earth, Venus and Mars: Comparisons with Circular Vent Eruptions

    NASA Technical Reports Server (NTRS)

    Glaze, Lori S.; Baloga, Stephen M.; Wimert, Jesse

    2010-01-01

    Conditions required to support buoyant convective plumes are investigated for explosive volcanic eruptions from circular and linear vents on Earth, Venus, and Mars. Vent geometry (linear versus circular) plays a significant role in the ability of an explosive eruption to sustain a buoyant plume. On Earth, linear and circular vent eruptions are both capable of driving buoyant plumes to equivalent maximum rise heights, however, linear vent plumes are more sensitive to vent size. For analogous mass eruption rates, linear vent plumes surpass circular vent plumes in entrainment efficiency approximately when L(sub o) > 3r(sub o) owing to the larger entrainment area relative to the control volume. Relative to circular vents, linear vents on Venus favor column collapse and the formation of pyroclastic flows because the range of conditions required to establish and sustain buoyancy is narrow. When buoyancy can be sustained, however, maximum plume heights exceed those from circular vents. For current atmospheric conditions on Mars, linear vent eruptions are capable of injecting volcanic material slightly higher than analogous circular vent eruptions. However, both geometries are more likely to produce pyroclastic fountains, as opposed to convective plumes, owing to the low density atmosphere. Due to the atmospheric density profile and water content on Earth, explosive eruptions enjoy favorable conditions for producing sustained buoyant columns, while pyroclastic flows would be relatively more prevalent on Venus and Mars. These results have implications for the injection and dispersal of particulates into the planetary atmosphere and the ability to interpret the geologic record of planetary volcanism.

  19. Exploring rock fissures: does a specialized root morphology explain endemism on granite outcrops?

    PubMed Central

    Poot, Pieter; Hopper, Stephen D.; van Diggelen, Josepha M.H.

    2012-01-01

    Background and Aims Worldwide, many plant species are confined to open, shallow-soil, rocky habitats. Although several hypotheses have been proposed to explain this habitat specificity, none has been convincing. We suggest that the high level of endemism on shallow soils is related to the edaphic specialization needed to survive in these often extremely drought-prone habitats. Previous research has shown that species endemic to ironstone communities in SW Australia have a specialized root morphology that enhances their chance to access fissures in the underlying rock. Here we test the generality of these findings for species that are confined to a shallow-soil habitat that is of much greater global significance: granite outcrops. Methods We compared temporal and spatial root growth and allocation of three endemic woody perennials of SW Australian granite outcrop communities with those of congeners occurring on nearby deeper soils. Seedlings of all species were grown in 1·2 m long custom-made containers with a transparent bottom that allowed monitoring of root growth over time. Key Results The granite outcrop endemics mostly differed in a predictable way from their congeners from deeper soils. They generally invested a larger portion of their biomass in roots, distributed their roots faster and more evenly over the container and had a lower specific root length. In different species pairs the outcrop endemics achieved their apparent advantage by a different combination of the aforementioned traits. Conclusions Our results are consistent with earlier work, indicating that species restricted to different types of drought-prone shallow-soil communities have undergone similar selection pressures. Although adaptive in their own habitat in terms of obtaining access to fissures in the underlying rock, these root system traits are likely to be maladaptive in deeper soil habitats. Therefore, our results may provide an explanation for the narrow endemism of many shallow

  20. Pleistocene microvertebrates from fissure-fillings in Thailand

    NASA Astrophysics Data System (ADS)

    Chaimanee, Yaowalak; Jaeger, Jean-Jacques; Suteethorn, Varavudh

    Microvertebrates (and among them specially, rodents) have contributed to the elaboration of precise biochronological time scales and to the reconstitution of Pleistocene paleoenvironments in several parts of the world (North America, Africa, Europe and Japan). They have been demonstrated to be highly sensitive to climatic changes since they are very sensitive to vegetation changes. Up to now, no data is available for Southeast Asia and very few information is available concerning the nature of climatic changes which affected that part of the tropical world during the Pleistocene. In the past few years, we have discovered several fissure fillings in Thailand yielding numerous remains of microvertebrates which have been extracted by dissolution in acetic acid solution. These deposits are the result of the feeding activity of predators, like owls or diurnal raptors, whose pellets are accumulated in caves or fissures. Eleven localities, located in Central (2), Eastern (1), Western (2) and Peninsular Thailand (6) have been investigated so far. Several rodent species, belonging to 9 genera of Murinae (rats and mice) and 9 genera of Sciuridae (squirrels) have been identified in these localities. The most important differences with the extant representatives often concern the size of the teeth of these fossil species. The meaning of these size differences is not yet clearly understood since they can be attributed either to significant time differences between localities (microevolution) or as the result of size variations related to climatic changes (clinical variations). More data will have to be collected to calibrate the temporal frame. Already, important modification of the geographic distribution of some species have been discovered which testify that during the Pleistocene, significative climatic changes have affected Southeast Asia. For example, Exilisciurus, a squirrel which is presently restricted to Borneo has been recognized in Peninsular Thailand. Also, Iomys

  1. Fissure sealant materials: Wear resistance of flowable composite resins

    PubMed Central

    Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

    2016-01-01

    Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm2 and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm2of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics.

  2. Fissure sealant materials: Wear resistance of flowable composite resins

    PubMed Central

    Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

    2016-01-01

    Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm2 and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm2of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics. PMID:27651887

  3. Fissure sealant materials: Wear resistance of flowable composite resins.

    PubMed

    Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

    2016-01-01

    Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm(2) and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm(2)of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics. PMID:27651887

  4. Fissure sealant materials: Wear resistance of flowable composite resins.

    PubMed

    Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

    2016-01-01

    Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm(2) and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm(2)of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics.

  5. Discrete element modeling on the crack evolution behavior of brittle sandstone containing three fissures under uniaxial compression

    NASA Astrophysics Data System (ADS)

    Yang, Sheng-Qi; Huang, Yan-Hua; Ranjith, P. G.; Jiao, Yu-Yong; Ji, Jian

    2015-12-01

    Based on experimental results of brittle, intact sandstone under uniaxial compression, the micro-parameters were firstly confirmed by adopting particle flow code (PFC^{2D}). Then, the validation of the simulated models were cross checked with the experimental results of brittle sandstone containing three parallel fissures under uniaxial compression. The simulated results agreed very well with the experimental results, including the peak strength, peak axial strain, and ultimate failure mode. Using the same micro-parameters, the numerical models containing a new geometry of three fissures are constructed to investigate the fissure angle on the fracture mechanical behavior of brittle sandstone under uniaxial compression. The strength and deformation parameters of brittle sandstone containing new three fissures are dependent to the fissure angle. With the increase of the fissure angle, the elastic modulus, the crack damage threshold, and the peak strength of brittle sandstone containing three fissures firstly increase and secondly decrease. But the peak axial strain is nonlinearly related to the fissure angle. In the entire process of deformation, the crack initiation and propagation behavior of brittle sandstone containing three fissures under uniaxial compression are investigated with respect to the fissure angle. Six different crack coalescence modes are identified for brittle sandstone containing three fissures under uniaxial compression. The influence of the fissure angle on the length of crack propagation and crack coalescence stress is evaluated. These investigated conclusions are very important for ensuring the stability and safety of rock engineering with intermittent structures.

  6. 46 CFR 151.15-5 - Venting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Pressure-vacuum venting. A normally closed venting system fitted with a device to automatically limit the pressure or vacuum in the tank to design limits. Pressure-vacuum relief valves shall comply with the... devices in accordance with the requirements of § 54.15-13 of this chapter. (2) When a...

  7. Hydrothermal Vents in Yellowstone Lake: Chemical Fluxes, Siliceous Deposits, and Collapse Structures

    NASA Astrophysics Data System (ADS)

    Shanks, W. P.; Morgan, L. A.; Balistrieri, L.; Alt, J.; Meeker, G.

    2002-12-01

    The geochemistry of Yellowstone Lake is strongly influenced by sublacustrine hydrothermal vent activity. The hydrothermal source fluid is identified using Cl and dD data on water column and sublacustrine hydrothermal vent fluid samples. Silica-rich hydrothermal deposits occur on the lake bottom near active and presently inactive hydrothermal vents. Pipe- and flange-like deposits contain cemented and recrystallized diatoms and represent pathways for hydrothermal fluid migration. Another major type of hydrothermal deposit comprises hard, porous siliceous spires up to 7 m tall that occur in 15 m of water in Bridge Bay. Bridge Bay spires are hydrothermal silica deposits formed in place by growth of chimney-like features from lake-bottom hydrothermal vents. The Cl concentrations indicate that Yellowstone Lake water is about 1 percent hydrothermal source fluid and 99 percent inflowing stream water and that the flux is about 10 percent of the total hydrothermal water flux in Yellowstone National Park. With recent swath-sonar mapping studies that show numerous new hydrothermal features, Yellowstone Lake should now be considered one of the most significant hydrothermal basins in the Park. Many lake-bottom hydrothermal vents occur in small depressions that are clearly imaged on multibeam sonar, some of which are interpreted as collapse structures based on seismic reflection data. Sediments collected from such vents show chemical evidence of leaching of 60-70 wt. percent SiO2, which may result in volume reductions up to 80 percent and provides a mechanism for vent structure formation.

  8. Infrasound from the 2007 fissure eruptions of Kīlauea Volcano, Hawai'i

    USGS Publications Warehouse

    Fee, D.; Garces, M.; Orr, T.; Poland, M.

    2011-01-01

    Varied acoustic signals were recorded at Kīlauea Volcano in mid-2007, coincident with dramatic changes in the volcano's activity. Prior to this time period, Pu'u 'Ō'ō crater produced near-continuous infrasonic tremor and was the primary source of degassing and lava effusion at Kīlauea. Collapse and draining of Pu'u 'Ō'ō crater in mid-June produced impulsive infrasonic signals and fluctuations in infrasonic tremor. Fissure eruptions on 19 June and 21 July were clearly located spatially and temporally using infrasound arrays. The 19 June eruption from a fissure approximately mid-way between Kīlauea's summit and Pu'u 'O'o produced infrasound for ~30 minutes-the only observed geophysical signal associated with the fissure opening. The infrasound signal from the 21 July eruption just east of Pu'u 'Ō'ō shows a clear azimuthal progression over time, indicative of fissure propagation over 12.9 hours. The total fissure propagation rate is relatively slow at 164 m/hr, although the fissure system ruptured discontinuously. Individual fissure rupture times are estimated using the acoustic data combined with visual observations.

  9. Are pit and fissure sealants needed in children with a higher caries risk?

    PubMed

    Berger, Susanne; Goddon, Inka; Chen, Chih-Mei; Senkel, Helga; Hickel, Reinhard; Stösser, Lutz; Heinrich-Weltzien, Roswitha; Kühnisch, Jan

    2010-10-01

    The aim of this cross-sectional study was to analyse the preventive need of pit and fissure sealants (PFS) in a German population with a relatively high caries risk. The study involved 311 8- to 12-year-old children from the Ennepe-Ruhr District in North Rhine-Westphalia, Germany. Caries experience was scored according to WHO (1997) and ICDAS II criteria. PFS were assessed as intact or partially lost. The mean DFS values amounted to 0.5 for occlusal fissures, 0.2 for palatal/buccal pits and 0.3 for the remaining teeth. Non-cavitated caries lesions were recorded in average on 1.8 occlusal fissures and 1.5 palatal/buccal pits. Sealants were registered on 1.4 occlusal fissures and 0.4 palatal/buccal pits. The descriptive data and the adjusted Poisson regression models revealed that children with at least one fissure sealant are less likely to have decayed fissures or fissures with non-cavitated lesions on their permanent molars. Therefore, PFS are needed and indicated in caries-risk children.

  10. Modeling of earth fissures caused by land subsidence due to groundwater withdrawal

    NASA Astrophysics Data System (ADS)

    Panda, B. B.; Rucker, M. L.; Fergason, K. C.

    2015-11-01

    Land subsidence and earth fissures are phenomena related to groundwater withdrawal in a sedimentary basin. If the rock basement or basin lithology is irregular, both vertical and horizontal displacements can be induced due to differential settlement and tensile stresses appearing in the soil mass. If the differential settlement is of sufficient magnitude, earth fissuring can occur within tensile zones. The magnitudes of compaction and fissure geometry are closely related to the thickness and skeletal compressibility of fine-grained sediments within the aquifer system. Land subsidence and earth fissuring were modeled by employing a two-dimensional (2-D) coupled seepage and stress-strain finite element analysis. The basin bedrock geometry, lithological variation, measurements of surface displacements, and changes in hydraulic head were the critical input parameter for the subsidence modeling. Simulation results indicate that strain had exceeded the approximate threshold for fissure formation of 0.02 to 0.06 % in the area of the identified fissures. The numerical model was used to predict future subsidence and potential earth fissures for flood control structures within the metro Phoenix area.

  11. Automatic segmentation of pulmonary fissures in computed tomography images using 3D surface features.

    PubMed

    Yu, Mali; Liu, Hong; Gong, Jianping; Jin, Renchao; Han, Ping; Song, Enmin

    2014-02-01

    Pulmonary interlobar fissures are important anatomic structures in human lungs and are useful in locating and classifying lung abnormalities. Automatic segmentation of fissures is a difficult task because of their low contrast and large variability. We developed a fully automatic training-free approach for fissure segmentation based on the local bending degree (LBD) and the maximum bending index (MBI). The LBD is determined by the angle between the eigenvectors of two Hessian matrices for a pair of adjacent voxels. It is used to construct a constraint to extract the candidate surfaces in three-dimensional (3D) space. The MBI is a measure to discriminate cylindrical surfaces from planar surfaces in 3D space. Our approach for segmenting fissures consists of five steps, including lung segmentation, plane-like structure enhancement, surface extraction with LBD, initial fissure identification with MBI, and fissure extension based on local plane fitting. When applying our approach to 15 chest computed tomography (CT) scans, the mean values of the positive predictive value, the sensitivity, the root-mean square (RMS) distance, and the maximal RMS are 91 %, 88 %, 1.01 ± 0.99 mm, and 11.56 mm, respectively, which suggests that our algorithm can efficiently segment fissures in chest CT scans.

  12. Neotectonic activity at the Giant Gjallar Vent (Norwegian Sea) indicates a future phase of active fluid venting

    NASA Astrophysics Data System (ADS)

    Dumke, Ines; Berndt, Christian; Crutchley, Gareth; Couillard, Mélanie; Gay, Aurélien

    2013-04-01

    The Giant Gjallar Vent (GGV) is a hydrothermal vent complex that formed during the opening of the North Atlantic at about 55 Ma. Sill intrusions into Cretaceous organic-rich sediments led to the production and subsequent vigorous seafloor venting of methane. A later phase of fluid escape occurred in mid-Oligocene times. The GGV is characterised by two pipes of 440 m and 480 m in diameter that reach up to the Base Late Pliocene Unconformity (BLPU) between the Kai and Naust formations. The unconformity is strongly deformed over an area of c. 18,000 km² across the vent, with a positive relief of up to 38 m above the surrounding paleo-seafloor. The overlying sediments of the Naust Formation conformally drape this deformation, smoothing its relief to a maximum of 15 m at the modern seafloor. The sediment drape indicates present inactivity of the vent system, as does the absence of indicators of active fluid escape in the water column during RV METEOR cruise M87-2 in 2012. However, high-resolution 2D seismic and Parasound data from the same cruise, and exploration-type 3D seismic data acquired by Norsk Hydro, show several indications for recent to ongoing activity at the GGV. Beneath the BLPU, strong frequency attenuation and chaotic reflections indicate the presence of free gas. At the edges of the extent of chaotic reflections, subvertical faults cut the unconformity as well as horizons of the lower and middle Naust Formation, suggesting tectonic activity after deposition of these horizons. Neotectonic activity is further indicated by the extensive occurrence of shallow faults apparent in Parasound records in the immediate vicinity of the vent and up to 16 km away. Some of these faults reach the seafloor. The observed deformation and faults may be the result of fluids accumulating beneath the BLPU due to increased loading of the oozy Kai Formation by denser glacigenic Naust sediments. Because of the lower permeability of the Naust Formation, the unconformity acts as a

  13. Cassini VIMS Spectra of the Thermal Emission from Hot Spots Along Enceladus South Pole Fissures

    NASA Astrophysics Data System (ADS)

    Goguen, Jay D.; Buratti, Bonnie J.; Cassini VIMS Team

    2016-10-01

    Most of the south pole fissure region has not been directly illuminated by sunlight since the sub-solar point moved into the northern hemisphere in 2009, thereby eliminating the background of reflected sunlight at VIMS wavelengths and making the fissure thermal emission readily measureable. Since then, VIMS has measured spectra of at least 11 hot spots along the fissures. Most of these measurements were acquired in ride-along mode with CIRS as the prime instrument. During at least 2 encounters, VIMS and CIRS acquired simultaneous or near-simultaneous spectra of the same fissure location. VIMS spectra include multiple hot spots along Damascus, Baghdad, Cairo, and a likely hot spot on Alexandria.All of the VIMS spectra examined to date are consistent with this scenario of a self-regulating fissure maximum T~200 K with brighter VIMS emissions corresponding to fissures up to ~20 m wide. Emission from the warm fissure interior walls dominate the VIMS spectra with <15% contributed by conductive heating of the adjacent terrain at VIMS wavelengths.CIRS spectra report slightly cooler T's due to CIRS increased sensitivity to lower T emission at longer wavelengths and averaging over contributions from both the hottest and cooler areas. Combined analysis of the CIRS and VIMS spectra spanning 3 to 500 micron wavelengths promises to reveal the distribution of [T, area] near the fissures that cannot be spatially resolved. This [T, area] distribution holds the key to understanding how heat is transferred to the surface within a few 100 m of the fissures.The VIMS-detected emission is concentrated in localized hot spots along the fissures and does not seem to be distributed continuously along them. CIRS spectra suggest a more continuous distribution of the emission along the fissure length. Jets locations also are distributed along the fissure length and it appears that the VIMS-detected hot spots in general correlate with jet locations, but not all of the jet locations have been

  14. Inhomogeneites dans le Vent des Etoiles Wolf-Rayet

    NASA Astrophysics Data System (ADS)

    Robert, Carmelle

    1992-01-01

    Des mesures spectroscopiques effectuees avec un haut rapport signal sur bruit et une bonne resolution ont demontre l'existence de regions perturbees en mouvement dans le vent d'etoiles Wolf-Rayet (WR). L'echantillon d'objets etudies ici comprend 9 etoiles WR couvrant differents sous-types WN et WC. De nombreuses petites structures variables superposees au profil des raies d'emission formees dans le vent stellaire signalent la presence des perturbations. L'etude des variations globales des raies et l'examen des micro-structures individuelles ont permis de decrire plusieurs caracteristiques des perturbations. Entre autres, on observe des correlations significatives entre le niveau de variabilite des raies et certains parametres des etoiles qui confirment que le phenomene de variabilite est intrinseque au vent stellaire. En comparant les changements des vitesses radiales et des largeurs equivalentes des differentes raies d'une meme etoile, on conclut que les regions perturbees ont une etendue finie par rapport a l'enveloppe des etoiles. On peut facilement suivre les structures individuelles sur une periode de temps couvrant ~eq8 heures (et peut etre meme 24 heures) avant qu'elles ne disparaissent. Durant ce temps les structures se deplacent en s'eloignant du centre de la raie. A partir des differents comportements notes lors de l'analyse des variations globales et lors de l'examen des structures individuelles, on propose de representer les perturbations par un modele d'inhomogeneites discretes en expansion dans le vent. On suppose simplement que les inhomogeneites emettent comme le vent global (et absorbent aussi si le vent global montre un profil P Cyg). La superposition du graphique de l'acceleration radiale moyenne des inhomogeneites de WR140 en fonction de leur vitesse radiale et du modele theorique d'inhomogeneites qui suivent la loi generale de vitesse donne un taux d'acceleration lent, avec beta >= 3 pour les inhomogeneites de cette etoile. On obtient, entre

  15. Geological and hydrothermal controls on the distribution of megafauna in Ashes Vent Field, Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Arquit, Anne M.

    1990-08-01

    A computerized data base was constructed to aid in the interpretation of biological and geological observations recorded from 7662 photographs taken of Ashes vent field (located along the SW wall of the summit caldera of Axial Volcano, Juan de Fuca Ridge) during 1985-1986 using the Pisces IV submersible and a towed camera system. The transition region between the locus of high-temperature vents in Ashes vent field (i.e., Inferno, 326°C; Hell, 301°C; and Virgin Mound, 298°C) and more typical environmental conditions for the summit caldera of Axial Volcano as a whole is zoned spatially with respect to sediment type and organism assemblage. Three general ecological zones are identified within the vent field: (1) the central vent zone (within 100 m of a high-temperature vent), dominated by vent-associated organisms (vestimentiferan tube worms, clams, bacterial mats) and sedimentation (high-temperature, plume-derived and low-temperature, in situ deposits); (2) the distal vent zone (100-725 m from any high-temperature vent), characterized by extensive fields of iron oxide, iron silicate and silica chimneys and sediment (nontronite assemblage material), as well as maximum densities of most nonvent fauna; and (3) the nonvent impact zone (725-1300 m), indicated by elevated densities of nonvent organisms relative to regional (i.e., caldera-wide) values and maximum Bathydorus sp. sponge densities. The distribution of vestimentiferan tube worms is limited to within 90 m of known high-temperature venting (central vent zone); and anemones were observed only between 30 and 40 m from hot vents. Clams and microbial mats are concentrated in the central vent zone, as well, but occur sporadically up to 1250 m from the hot vents in association with hydrothermal nontronite that is probably precipitating in situ from <60°C vent fluid; thus megafaunal distributions are a useful indicator of poorly defined, often diffuse low-temperature hydrothermal activity on the seafloor. Maximum

  16. Painless Ulcers and Fissures of Toes: Hereditary Sensory Neuropathy, Not Leprosy

    PubMed Central

    Rao, Angoori Gnaneshwar

    2016-01-01

    Hereditary sensory neuropathies (HSN) are rare genetically determined neuropathies. They often manifest as painless injuries in children. We present HSN in a 5-year-old boy who presented with recurrent fissuring and ulceration involving both great toes. PMID:26955138

  17. Putative fissure-resistance QTLs mapped to chromosomes 1 and 8 based on allelic frequency differences observed between fissure-resistant and fissure-susceptible progeny from two segregating populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whole rice kernels have two to three times more market value than broken, which means that any reduction in milling yield results in financial losses for both rice producers and millers. One of the primary causes of rice breakage during milling is fissuring of the rice before it even enters the mil...

  18. Diverse styles of submarine venting on the ultra-slow spreading Mid-Cayman Rise (Invited)

    NASA Astrophysics Data System (ADS)

    German, C. R.; Bowen, A.; Coleman, M. L.; Honig, D. L.; Huber, J. A.; Jakuba, M.; Kinsey, J. C.; Kurz, M. D.; Leroy, S.; McDermott, J.; Mercier de Lepinay, B. F.; Nakamura, K.; Seewald, J.; Smith, J.; Sylva, S.; van Dover, C. L.; Whitcomb, L. L.; Yoerger, D. R.

    2010-12-01

    Thirty years after the first discovery of high-temperature submarine venting, the vast majority of the global Mid Ocean Ridge remains unexplored for hydrothermal activity. Of particular interest are the world’s ultra-slow spreading ridges which were the last to be demonstrated to host high-temperature venting, but may host systems particularly relevant to pre-biotic chemistry and the origins of life. Here we report first evidence for diverse and very deep hydrothermal vents along the ~110 km long, ultra-slow spreading Mid-Cayman Rise collected using a combination of CTD-rosette operations and dives of the Hybrid Remotely Operated Vehicle (HROV) Nereus in 2009 followed by shore based work-up of samples for geochemical and microbiological analyses. Our data indicate that the Mid-Cayman Rise hosts at least three discrete hydrothermal sites, each representing a different type of water-rock interaction, including both mafic and ultra-mafic systems and, at ~5000 m, the deepest known hydrothermal vent. Although submarine hydrothermal circulation, in which seawater percolates through and reacts with host lithologies, occurs on all mid-ocean ridges, the diversity of vent-types identified here and their relative geographic isolation make the Mid-Cayman Rise unique in the oceans. These new sites offer prospects for: an expanded range of vent-fluid compositions; varieties of abiotic organic chemical synthesis and extremophile microorganisms; and unparalleled faunal biodiversity - all in close proximity.

  19. Diverse styles of submarine venting on the ultraslow spreading Mid-Cayman Rise

    PubMed Central

    German, C. R.; Bowen, A.; Coleman, M. L.; Honig, D. L.; Huber, J. A.; Jakuba, M. V.; Kinsey, J. C.; Kurz, M. D.; Leroy, S.; McDermott, J. M.; de Lépinay, B. Mercier; Nakamura, K.; Seewald, J. S.; Smith, J. L.; Sylva, S. P.; Van Dover, C. L.; Whitcomb, L. L.; Yoerger, D. R.

    2010-01-01

    Thirty years after the first discovery of high-temperature submarine venting, the vast majority of the global mid-ocean ridge remains unexplored for hydrothermal activity. Of particular interest are the world’s ultraslow spreading ridges that were the last to be demonstrated to host high-temperature venting but may host systems particularly relevant to prebiotic chemistry and the origins of life. Here we report evidence for previously unknown, diverse, and very deep hydrothermal vents along the ∼110 km long, ultraslow spreading Mid-Cayman Rise (MCR). Our data indicate that the MCR hosts at least three discrete hydrothermal sites, each representing a different type of water-rock interaction, including both mafic and ultramafic systems and, at ∼5,000 m, the deepest known hydrothermal vent. Although submarine hydrothermal circulation, in which seawater percolates through and reacts with host lithologies, occurs on all mid-ocean ridges, the diversity of vent types identified here and their relative geographic isolation make the MCR unique in the oceans. These new sites offer prospects for an expanded range of vent-fluid compositions, varieties of abiotic organic chemical synthesis and extremophile microorganisms, and unparalleled faunal biodiversity—all in close proximity. PMID:20660317

  20. Diverse styles of submarine venting on the ultraslow spreading Mid-Cayman Rise.

    PubMed

    German, C R; Bowen, A; Coleman, M L; Honig, D L; Huber, J A; Jakuba, M V; Kinsey, J C; Kurz, M D; Leroy, S; McDermott, J M; de Lépinay, B Mercier; Nakamura, K; Seewald, J S; Smith, J L; Sylva, S P; Van Dover, C L; Whitcomb, L L; Yoerger, D R

    2010-08-10

    Thirty years after the first discovery of high-temperature submarine venting, the vast majority of the global mid-ocean ridge remains unexplored for hydrothermal activity. Of particular interest are the world's ultraslow spreading ridges that were the last to be demonstrated to host high-temperature venting but may host systems particularly relevant to prebiotic chemistry and the origins of life. Here we report evidence for previously unknown, diverse, and very deep hydrothermal vents along the approximately 110 km long, ultraslow spreading Mid-Cayman Rise (MCR). Our data indicate that the MCR hosts at least three discrete hydrothermal sites, each representing a different type of water-rock interaction, including both mafic and ultramafic systems and, at approximately 5,000 m, the deepest known hydrothermal vent. Although submarine hydrothermal circulation, in which seawater percolates through and reacts with host lithologies, occurs on all mid-ocean ridges, the diversity of vent types identified here and their relative geographic isolation make the MCR unique in the oceans. These new sites offer prospects for an expanded range of vent-fluid compositions, varieties of abiotic organic chemical synthesis and extremophile microorganisms, and unparalleled faunal biodiversity--all in close proximity.

  1. Monitoring arrangement for vented nuclear fuel elements

    DOEpatents

    Campana, Robert J.

    1981-01-01

    In a nuclear fuel reactor core, fuel elements are arranged in a closely packed hexagonal configuration, each fuel element having diametrically opposed vents permitting 180.degree. rotation of the fuel elements to counteract bowing. A grid plate engages the fuel elements and forms passages for communicating sets of three, four or six individual vents with respective monitor lines in order to communicate vented radioactive gases from the fuel elements to suitable monitor means in a manner readily permitting detection of leakage in individual fuel elements.

  2. Catalytic Diversity in Alkaline Hydrothermal Vent Systems on Ocean Worlds

    NASA Astrophysics Data System (ADS)

    Cameron, Ryan D.; Barge, Laura; Chin, Keith B.; Doloboff, Ivria J.; Flores, Erika; Hammer, Arden C.; Sobron, Pablo; Russell, Michael J.; Kanik, Isik

    2016-10-01

    Hydrothermal systems formed by serpentinization can create moderate-temperature, alkaline systems and it is possible that this type of vent could exist on icy worlds such as Europa which have water-rock interfaces. It has been proposed that some prebiotic chemistry responsible for the emergence of life on Earth and possibly other wet and icy worlds could occur as a result ofredox potential and pH gradients in submarine alkaline hydrothermal vents (Russell et al., 2014). Hydrothermal chimneys formed in laboratory simulations of alkaline vents under early Earth conditions have precipitate membranes that contain minerals such as iron sulfides, which are hypothesized to catalyze reduction of CO2 (Yamaguchi et al. 2014, Roldan et al. 2014) leading to further organic synthesis. This CO2 reduction process may be affected by other trace components in the chimney, e.g. nickel or organic molecules. We have conducted experiments to investigate catalytic properties of iron and iron-nickel sulfides containing organic dopants in slightly acidic ocean simulants relevant to early Earth or possibly ocean worlds. We find that the electrochemical properties of the chimney as well as the morphology/chemistry of the precipitate are affected by the concentration and type of organics present. These results imply that synthesis of organics in water-rock systems on ocean worlds may lead to hydrothermal precipitates which can incorporate these organic into the mineral matrix and may affect the role of gradients in alkaline vent systems.Therefore, further understanding on the electroactive roles of various organic species within hydrothermal chimneys will have important implications for habitability as well as prebiotic chemistry. This work is funded by NASA Astrobiology Institute JPL Icy Worlds Team and a NAI Director's Discretionary Fund award.Yamaguchi A. et al. (2014) Electrochimica Acta, 141, 311–318.Russell, M. J. et al. (2014), Astrobiology, 14, 308-43.Roldan, A. (2014) Chem. Comm

  3. 46 CFR 153.358 - Venting system flow capacity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Venting system flow capacity. 153.358 Section 153.358... Venting Systems § 153.358 Venting system flow capacity. (a) The cross-sectional flow area of any vent system segment, including any PV or SR valve, must at no point be less than that of a pipe whose...

  4. 40 CFR 65.62 - Process vent group determination.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Process vent group determination. 65... (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Process Vents § 65.62 Process vent group determination. (a) Group status. The owner or operator of a process vent shall determine the group status (i.e., Group 1, Group...

  5. 14 CFR 125.159 - Vent and drain lines.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Vent and drain lines. 125.159 Section 125... Requirements § 125.159 Vent and drain lines. All vent and drain lines, and their fittings, that are located in... Administrator finds that the rupture or breakage of any vent or drain line may result in a fire hazard....

  6. 40 CFR 63.1321 - Batch process vents provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... vent streams except as specified in paragraphs (b)(1) through (b)(2) of this section. For continuous... and aggregate batch vent streams, the control requirements for individual batch process vents or aggregate batch vent streams (e.g., 90 percent emission reduction) as specified in § 63.1322(a)(1),...

  7. Monitoring on Xi'an ground fissures deformation with TerraSAR-X data

    USGS Publications Warehouse

    Zhao, C.; Zhang, Q.; Zhu, W.; Lu, Zhiming

    2012-01-01

    Owing to the fine resolution of TerraSAR-X data provided since 2007, this paper applied 6 TerraSAR data (strip mode) during 3rd Dec. 2009 to 23rd Mar. 2010 to detect and monitor the active fissures over Xi'an region. Three themes have been designed for high precision detection and monitoring of Xi'an-Chang'an fissures, as small baseline subsets (SBAS) to test the atmospheric effects of differential interferograms pair stepwise, 2-pass differential interferogram with very short baseline perpendicular to generate the whole deformation map with 44 days interval, and finally, corner reflector (CR) technique was used to closely monitor the relative deformation time series between two CRs settled crossing two ground fissures. Results showed that TerraSAR data are a good choice for small-scale ground fissures detection and monitoring, while special considerations should be taken for their great temporal and baseline decorrelation. Secondly, ground fissures in Xi'an were mostly detected at the joint section of stable and deformable regions. Lastly, CR-InSAR had potential ability to monitor relative deformation crossing fissures with millimeter precision.

  8. RECURRENT ECTOPIC CRANIOPHARYNGIOMA IN THE SYLVIAN FISSURE THIRTY YEARS AFTER RESECTION THROUGH A PTERIONAL APPROACH: A CASE REPORT AND REVIEW OF THE LITERATURE

    PubMed Central

    CLARK, SHANNON W.; KENNING, TYLER J.; EVANS, JAMES J.

    2015-01-01

    ABSTRACT Local recurrence of craniopharyngiomas after apparently complete resection occurs frequently. Ectopic recurrence remote from the original site has been reported in 18 adult patients. The interval between the original diagnosis and the time of recurrence varies widely in these reports (1–26 years). We report a case of an ectopic recurrence in the sylvian fissure of an adamantinomatous type craniopharyngioma 34 years after the initial presentation and 30 years after the last surgical resection. In addition to this being the latest reported ectopic recurrence, the location of this new lesion in the sylvian fissure is fairly rare, having been reported in only three other cases. We also reviewed the English literature for reports of ectopic recurrent craniopharyngiomas in order to conduct an analysis of surveillance and treatment strategies. PMID:25797995

  9. The geochemical controls on vent fluids from the Lucky Strike vent field, Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Von Damm, K. L.; Bray, A. M.; Buttermore, L. G.; Oosting, S. E.

    1998-08-01

    Hydrothermal vent fluids were collected from the Lucky Strike site at 37°17'N on the Mid-Atlantic Ridge in both 1993 and 1996. Seven vents were sampled with the DSV Alvin in 1993 and six vents were sampled in 1996 using the ROV Jason during the LUSTRE '96 Cruise. As three of the vents were sampled in both 1993 and in 1996, a time series of vent fluid chemistry is also reported. Measured temperatures ranged from 202 to 333°C at the 1618-1726 m depth of the vent field, which is located on Lucky Strike Seamount. These fluids are either equal to or less than the local bottom seawater in chlorinity. While the range in fluid compositions at Lucky Strike is generally within that observed elsewhere, the unusual aspects of the fluid chemistries are the relatively high pH and low Fe, Mn, Li and Zn. We attribute this, as well as an usually low Sr/Ca ratio, to reaction with a highly altered substrate. The high Si and Cu contents suggest a deep, as well as hot, source for these fluids. The fluid compositions therefore suggest formation by super-critical phase separation at a depth not less than 1300 m below the seafloor, and reaction with a relatively oxic, and previously altered, substrate. There is temporal variability in some of the vent fluid compositions as Li, K, Ca and Fe concentrations have increased in some of the vents, as has the Fe/Mn (molar) ratio, although the chlorinities have remained essentially constant from 1993 to 1996. While there is not a simple relationship between vent fluid compositions (or temperatures) and distance from the lava lake at the summit of the seamount, the vent fluids from many of the vents can be shown to be related to others, often at distances >200 m. The most southeasterly vents (Eiffel Tower and the Marker/Mounds vents) are distinct in chlorinity and other chemical parameters from the rest of the vents, although closely related to each other within the southeastern area. Similarly all of the vents not in this one area, appear

  10. Geologic form and setting of a hydrothermal vent field at latitude 10/sup 0/56'N, East Pacific Rise: a detailed study using Angus and Alvin

    SciTech Connect

    McConachy, T.F.; Ballard, R.D.; Mottl, M.J.; Von Herzen, R.P.

    1986-04-01

    A hydrothermal vent field, here called the Feather Duster site, occurs on the eastern marginal high near the edge of a narrow (95-m) and shallow (15-20-m) axial graben, within an area dominated by sheet flows and collapse features. The sheet flows are intermediate in relative age between younger fluid-flow lavas on the floor of the axial graben and older pillow (constructional) lavas on the marginal highs. Hydrothermal activity occurs in two zones within a 65 by 45 m area. The main zone is located where a fissure system and sulfide-sulfate chimneys vent warm (9-47/sup 0/C) and hot (347/sup 0/C) hydrothermal fluids. Here, two mounds of massive sulfide totaling about 200 t are forming. One occurs at the base of a 3-m-high scarp which is the wall of a drained lava lake; the other is perched on top of the scarp. 19 references, 4 figures.

  11. Fracturing and earthquake activity within the Prestahnúkur fissure swarm in the Western Volcanic Rift Zone of Iceland

    NASA Astrophysics Data System (ADS)

    Hjartardóttir, Ásta Rut; Hjaltadóttir, Sigurlaug; Einarsson, Páll; Vogfjörd, Kristín.; Muñoz-Cobo Belart, Joaquín.

    2015-12-01

    The Prestahnúkur fissure swarm is located within the ultraslowly spreading Western Volcanic Zone in Iceland. The fissure swarm is characterized by normal faults, open fractures, and evidence of subglacial fissure eruptions (tindars). In this study, fractures and faults within the Prestahnúkur fissure swarm were mapped in detail from aerial photographs to determine the extent and activity of the fissure swarm. Earthquakes during the last ~23 years were relocated to map the subsurface fault planes that they delineate. The Prestahnúkur fissure swarm is 40-80 km long and up to ~20 km wide. Most of the areas of the fissure swarm have been glacially eroded, although a part of it is covered by postglacial lava flows. The fissure swarm includes numerous faults with tens of meters vertical offset within the older glacially eroded part, whereas open fractures are found within postglacial lava flows. Comparison of relocated earthquakes and surface fractures indicates that some of the surface fractures have been activated at depth during the last ~23 years, although no dike intrusions have been ongoing. The existence of tindars nevertheless indicates that dike intrusions and rifting events do occur within the Prestahnúkur fissure swarm. The low-fracture density within postglacial lava flows and low density of postglacial eruptive fissures indicate that rifting episodes occur less often than in the faster spreading Northern Volcanic Zone.

  12. Identification of possible recent water/lava source fissures in the Cerberus Plains: stratigraphic and crater count age constraints

    NASA Astrophysics Data System (ADS)

    Thomas, Rebecca J.

    2013-04-01

    The Cerberus plains are one of the youngest surfaces on Mars. They are thought to have been formed by lava and/or water flows, but there is considerable debate regarding the source of this material. Much of the material forming the western plains, including the Athabasca Valles outflow channels, appears to have flowed from the region of the Cerberus Fossae graben system [1,2,3] and limited areas forming the eastern plains may have been erupted by low shield volcanoes [4,5]. However, flow of material from west to east is obstructed by a ridge centred on 157°E, 7°N and, prior to this study, vents which might be the source of fluid of a low enough viscosity to form the majority of the flat eastern plains had not been identified. We studied new HiRISE (25cm/px, High Resolution Science Imaging Experiment) images of the ridge between the east and west plains and observed possible source vents for this material: the ridge is cut by a series of pits and fissures which lie at the heads of flows and channels extending towards the surrounding plains. In order to establish the stratigraphic relationships between the vents and plains, this study produced large scale geomorphological maps based on the HiRISE images. The mapping showed that both incised channels and leveed flows extend onto the plain to the south of the ridge and that these were the final phase of plains-forming activity in that region. Conversely, to the north, ridge-sourced deposits only form the plains surface close to the ridge - beyond that, they are overlain by large-scale regional flows that appear to have originated from the direction of Athabasca Valles. In the southeast, a large-scale flow which does not emanate from this ridge forms the plains surface, but there is evidence that the youngest outflow activity from the ridge was contemporaneous with emplacement of this unit. We also performed crater counts to age-date the surfaces and these indicate that plains-forming and ridge-sourced units are of a

  13. The vent microbiome: patterns and drivers

    NASA Astrophysics Data System (ADS)

    Pachiadaki, M.

    2015-12-01

    Microbial processes within deep-sea hydrothermal vents affect the global biogeochemical cycles. Still, there are significant gaps in our understanding of the microbiology and the biogeochemistry of deep-sea hydrothermal systems. Vents differ in temperature, host rock composition and fluid chemistry; factors that are hypothesized to shape the distribution of the microbial communities, their metabolic capabilities and their activities. Using large-scale single cell genomics, we obtained insights into the genomic content of several linkages of a diffuse flow vent. The genomes show high metabolic versatility. Sulfur oxidation appears to be predominant but there is the potential of using a variety of e- donors and acceptors to obtain energy. To further assess the ecological importance of the vent auto- and heterotrophs, the global biogeography of the analyzed lineages will be investigated by fragment recruitment of metagenomes produced from the same site as well as other hydrothermal systems. Metatranscriptomic and metaproteomic data will be integrated to examine the expression of the predominant metabolic pathways and thus the main energy sources driving chemoautotrophic production. The comparative analysis of the key players and associated pathways among various vent sites that differ in physicochemical characteristics is anticipated to decipher the patterns and drivers of the global dispersion and the local diversification of the vent microbiome.

  14. Explosion testing for the container venting system

    SciTech Connect

    Cashdollar, K.L.; Green, G.M.; Thomas, R.A.; Demiter, J.A.

    1993-09-30

    As part of the study of the hazards of inspecting nuclear waste stored at the Hanford Site, the US Department of Energy and Westinghouse Hanford Company have developed a container venting system to sample the gases that may be present in various metal drums and other containers. In support of this work, the US Bureau of Mines has studied the probability of ignition while drilling into drums and other containers that may contain flammable gas mixtures. The Westinghouse Hanford Company drilling procedure was simulated by tests conducted in the Bureau`s 8-liter chamber, using the same type of pneumatic drill that will be used at the Hanford Site. There were no ignitions of near-stoichiometric hydrogen-air or methane-air mixtures during the drilling tests. The temperatures of the drill bits and lids were measured by an infrared video camera during the drilling tests. These measured temperatures are significantly lower than the {approximately}500{degree}C autoignition temperature of uniformly heated hydrogen-air or the {approximately}600{degree}C autoignition temperature of uniformly heated methane-air. The temperatures are substantially lower than the 750{degree}C ignition temperature of hydrogen-air and 1,220{degree}C temperature of methane-air when heated by a 1-m-diameter wire.

  15. Comparative study of vent and seep macrofaunal communities in the Guaymas Basin

    NASA Astrophysics Data System (ADS)

    Portail, M.; Olu, K.; Escobar-Briones, E.; Caprais, J. C.; Menot, L.; Waeles, M.; Cruaud, P.; Sarradin, P. M.; Godfroy, A.; Sarrazin, J.

    2015-06-01

    Understanding the ecological processes and connectivity of chemosynthetic deep-sea ecosystems requires comparative studies. In the Guaymas Basin (Gulf of California, Mexico), the presence of seeps and vents in the absence of biogeographic barrier, comparable sedimentary settings and depths offers a unique opportunity to assess the role of ecosystem specific environmental conditions on macrofaunal communities. Six seep and four vent assemblages were studied, three of which were characterised by common major foundation taxa: vesicomyid bivalves, siboglinid tubeworms and microbial mats. Macrofaunal community structure at the family level showed that density, diversity and composition patterns were primarily shaped by seep and vent common abiotic factors including methane and hydrogen sulphide concentrations. The type of substratum and the heterogeneity provided by foundation species were identified as additional structuring factors and their roles were found to vary according to fluid regimes. Surprisingly, the presence of vent environmental specificities, with higher temperature, higher metal concentrations and lower pH was not significant in explaining community patterns. Moreover, Guaymas seep and vent shared an important number of common species suggesting frequent connections between the two ecosystems. Finally, this study provides further support for the hypothesis of continuity among deep-sea seep and vent ecosystems.

  16. Measurement of kinetic energy dissipation with gelatine fissure formation with special reference to gelatine validation.

    PubMed

    Jussila, Jorma

    2005-05-28

    Various methods for calculating the amount of kinetic energy dissipated by a bullet into ballistic gelatine have been suggested in literature. These methods were compared using the results of thirteen 9 mmx19 mm pistol and five 7.62 mmx 39 mm rifle bullets shot into 10% ballistic gelatine. The Wound Profile Method gave the highest correlation, 0.89, with the measured amounts of dissipated kinetic energy. The Fissure surface area and total crack length method gained 0.51 and 0.52, respectively. The experimental results were also compared with those from pig tests with the same bullet types. Using the z-test at 95% level of confidence no difference between impact velocity normalized bullet decelerations could be determined for the 9 mm bullet used. The same test showed significant difference for 7.62 mm bullets. That, however, can be considered to be the result of the bullet's tendency to tumble in non-homogenous living tissue causing significant dispersion of observed deceleration values. The results add further evidence supporting the validity of 10% gelatine at +4 degrees C as wound ballistic tissue simulant. The study also introduces the use of an elastic "shroud" to hold the gelatine in place, to some extent reduce the effects of asymmetric expansion of the gelatine and to simulate the expansion suppression effect of surrounding tissues. PMID:15837008

  17. Energy metabolism and cellular homeostasis trade-offs provide the basis for a new type of sensitivity to ocean acidification in a marine polychaete at a high-CO2 vent: adenylate and phosphagen energy pools versus carbonic anhydrase.

    PubMed

    Turner, Lucy M; Ricevuto, Elena; Massa-Gallucci, Alexia; Gambi, Maria-Cristina; Calosi, Piero

    2015-07-01

    Species distributions and ecology can often be explained by their physiological sensitivity to environmental conditions. Whilst we have a relatively good understanding of how these are shaped by temperature, for other emerging drivers, such as PCO2  we know relatively little. The marine polychaete Sabella spallanzanii increases its metabolic rate when exposed to high PCO2  conditions and remains absent from the CO2 vent of Ischia. To understand new possible pathways of sensitivity to CO2 in marine ectotherms, we examined the metabolic plasticity of S. spallanzanii exposed in situ to elevated PCO2  by measuring fundamental metabolite and carbonic anhydrase concentrations. We show that whilst this species can survive elevated PCO2  conditions in the short term, and exhibits an increase in energy metabolism, this is accompanied by a significant decrease in carbonic anhydrase concentration. These homeostatic changes are unlikely to be sustainable in the longer term, indicating S. spallanzanii may struggle with future high PCO2  conditions.

  18. Comparison of Various Concentrations of Tricalcium Phosphate Nanoparticles on Mechanical Properties and Remineralization of Fissure Sealants

    PubMed Central

    Tavassoli-Hojjati, Sara; Atai, Mohammad; Haghgoo, Roza; Rahimian-Imam, Sara; Kameli, Somayeh; Ahmaian-Babaki, Fatemeh; Hamzeh, Faezeh; Ahmadyar, Maryam

    2014-01-01

    Objective: The aim of this study was to investigate the mechanical properties (flexural strength, micro-shear bond strength) and remineralizing potential of fissure sealants by adding various concentrations of β-tricalcium phosphate nanoparticles. Materials and Methods: This in-vitro study consisted of five experimental groups containing prepared nano-fisssure sealants (1–5 wt.% β-TCP nanoparticles) and two control groups containing a prepared and a commercial fissure sealant. Flexural/micro-shear bond strength values were measured using Zwick test machine. Cavities on sixty healthy premolar teeth were filled with the fissure sealants containing 0–5 wt.% of nano β-TCP. The samples were assessed for remineralization under scanning electron microscopy (SEM) and EDAX. Kolmogorov-Smirnov test, One-way ANOVA and Tukey’s Post Hoc analysis/HSD were used to analyze the data. Results: There was no significant difference between the flexural strengths/elastic modulus of the 0–5 wt.% nano β-TCP groups (p>0.05). The average flexural strength/elastic modulus of the prepared fissure sealant group (0%) was significantly higher than the commercial fissure sealant group (Clinpro) (p<0.05). There was no significant difference between micro-shear bond strengths of the experimental groups (1–5 wt.%), and between the commercial and the prepared (0%) fissure sealant groups (p>0.05). Examining the samples under SEM showed a significant increase in thickness of the intermediate layer with increasing concentrations of β-TCP nanoparticles (p<0.05). Conclusion: Addition of 1–5 wt.% β-TCP nanoparticles to the fissure sealants significantly increased the remineralization potential without affecting the mechanical properties. PMID:25584048

  19. Retention of resin-based filled and unfilled pit and fissure sealants: A comparative clinical study

    PubMed Central

    Reddy, V. Rajashekar; Chowdhary, Nagalakshmi; Mukunda, K. S.; Kiran, N. K.; Kavyarani, B. S.; Pradeep, M. C.

    2015-01-01

    Background and Objectives: The most caries-susceptible period of a permanent first molar tooth is the eruption phase, during which the enamel is not fully matured and it is usually difficult for the child to clean the erupting tooth surfaces. Sealing occlusal pits and fissures with resin-based pit and fissure sealants is a proven method to prevent occlusal caries. The difference in the viscosity of the sealants differs in the penetration into pit and fissures and abrasive wear resistance property due to the addition of filler particles. The present study was conducted to evaluate and compare the retention of the resin-based filled (Helioseal F, Ivoclar Vivadent) and unfilled (Clinpro, 3M ESPE) pit and fissure sealants, which is important for their effectiveness. Materials and Methods: Fifty-six children between the age group of 6 and 9 years, with all four newly erupted permanent first molars were selected. Sealants were applied randomly using split mouth design technique on permanent first molars. Evaluation of sealant retention was performed at regular intervals over 12 months, using Simonsen's criteria at 2nd, 4th, 6th, 8th, 10th and 12th month. The results were subjected to statistical analysis. Results: At the end of our study period (12th month), 53.57% showed complete retention, 37.50% showed partial retention, and 8.83% showed complete missing of resin-based filled (Helioseal F) pit and fissure sealant. And, 64.29% showed complete retention, 32.14% showed partial retention, and 3.57% showed complete missing of resin-based unfilled (Clinpro) pit and fissure sealant. This difference in retention rates between filled and unfilled pit and fissure sealants was not statistically significant. Conclusion: The difference in retention rates between Helioseal F and Clinpro was not statistically significant, but Clinpro (unfilled) sealant showed slightly higher retention rates and clinically better performance than Helioseal F (filled). PMID:25821368

  20. ANALYSIS OF VENTING OF A RESIN SLURRY

    SciTech Connect

    Laurinat, J.; Hensel, S.

    2012-03-27

    A resin slurry venting analysis was conducted to address safety issues associated with overpressurization of ion exchange columns used in the Purex process at the Savannah River Site (SRS). If flow to these columns were inadvertently interrupted, an exothermic runaway reaction could occur between the ion exchange resin and the nitric acid used in the feed stream. The nitric acid-resin reaction generates significant quantities of noncondensable gases, which would pressurize the column. To prevent the column from rupturing during such events, rupture disks are installed on the column vent lines. The venting analysis models accelerating rate calorimeter (ARC) tests and data from tests that were performed in a vented test vessel with a rupture disk. The tests showed that the pressure inside the test vessel continued to increase after the rupture disk opened, though at a slower rate than prior to the rupture. Calculated maximum discharge rates for the resin venting tests exceeded the measured rates of gas generation, so the vent size was sufficient to relieve the pressure in the test vessel if the vent flow rate was constant. The increase in the vessel pressure is modeled as a transient phenomenon associated with expansion of the resin slurry/gas mixture upon rupture of the disk. It is postulated that the maximum pressure at the end of this expansion is limited by energy minimization to approximately 1.5 times the rupture disk burst pressure. The magnitude of this pressure increase is consistent with the measured pressure transients. The results of this analysis demonstrate the need to allow for a margin between the design pressure and the rupture disk burst pressure in similar applications.

  1. Examination of frit vent from Sixty-Watt Heat Source simulant fueled clad vent set

    SciTech Connect

    Ulrich, G.B.

    1995-11-01

    The flow rate and the metallurgical condition of a frit vent from a simulant-fueled clad vent set (CVS) that had been hot isostatically pressed (HIP) for the Sixty-Watt Heat Source program were evaluated. The flow rate form the defueled vent cup subassembly was reduced approximately 25% from the original flow rate. No obstructions were found to account for the reduced flow rate. Measurements indicate that the frit vent powder thickness was reduced about 30%. Most likely, the powder was compressed during the HIP operation, which increased the density of the powder layer and thus reduced the flow rate of the assembly. All other observed manufacturing attributes appeared to be normal, but the vent hole activation technique needs further refinement before it is used in applications requiring maximum CVS integrity.

  2. In vitro evaluation of shear bond strength and microleakage of different pit and fissure sealants

    PubMed Central

    Babaji, Prashant; Vaid, Shivali; Deep, S.; Mishra, Samvit; Srivastava, Madhulika; Manjooran, Thomas

    2016-01-01

    Aim and Objectives: Fissure caries is most common in children due to deep pit and fissures. Pit and fissure areas on the occlusal surface of the teeth make them susceptible to dental caries, which need to be prevented or restored. Fissures sealant reduces the risk of occlusal caries. The present study was done to evaluate microleakage and shear bond strength of various fissure sealants. Materials and Methods: Thirty-six extracted molars were randomly allocated equally (n = 12) into three groups with three different sealants to evaluate shear bond strength and microleakage at sealant space. The shear bond strengths was evaluated with one-way analysis of variance and microleakage by Kruskal-Wallis nonparametric test using the Statistical Package for the Social Sciences version 18.0 (Chicago: SPSS Inc, 2009). Results: Tetric flow (16.8 MPa) recorded the highest shear bond strength and the difference was statistically significant with enamel loc (12.8 MPa). There was no statistically significant difference in relation to microleakage (P > 0.05) in the tested groups. Conclusions: Tetric flow recorded the highest shear bond strength and the difference was statistically significant with enamel loc. However, there was no statistically significant difference among the groups regarding microleakage.

  3. In vitro evaluation of shear bond strength and microleakage of different pit and fissure sealants

    PubMed Central

    Babaji, Prashant; Vaid, Shivali; Deep, S.; Mishra, Samvit; Srivastava, Madhulika; Manjooran, Thomas

    2016-01-01

    Aim and Objectives: Fissure caries is most common in children due to deep pit and fissures. Pit and fissure areas on the occlusal surface of the teeth make them susceptible to dental caries, which need to be prevented or restored. Fissures sealant reduces the risk of occlusal caries. The present study was done to evaluate microleakage and shear bond strength of various fissure sealants. Materials and Methods: Thirty-six extracted molars were randomly allocated equally (n = 12) into three groups with three different sealants to evaluate shear bond strength and microleakage at sealant space. The shear bond strengths was evaluated with one-way analysis of variance and microleakage by Kruskal-Wallis nonparametric test using the Statistical Package for the Social Sciences version 18.0 (Chicago: SPSS Inc, 2009). Results: Tetric flow (16.8 MPa) recorded the highest shear bond strength and the difference was statistically significant with enamel loc (12.8 MPa). There was no statistically significant difference in relation to microleakage (P > 0.05) in the tested groups. Conclusions: Tetric flow recorded the highest shear bond strength and the difference was statistically significant with enamel loc. However, there was no statistically significant difference among the groups regarding microleakage. PMID:27652241

  4. Maps showing water-level declines, land subsidence, and earth fissures in south-central Arizona

    USGS Publications Warehouse

    Laney, R.L.; Raymond, R.H.; Winikka, C.C.

    1978-01-01

    From 1915 to 1975, more than 109 million acre-feet of ground water was withdrawn from about 4,500 square miles in Pinal and Maricopa Counties in south-central Arizona. The volume of water withdrawn greatly exceeds the volume of natural recharge, and water levels have been declining since 1923. As a result of the water-level declines, the land surface has subsided, the alluvial deposits have been subjected to stress, and earth fissures have developed. Land subsidence and earth fissures have damaged public and private properties. Subsidence and fissures will continue to occur as long as ground water is being mined and water levels continue to decline. As urban development expands, land subsidence and earth fissures will have an increasing socioeconomic impact. Information on maps includes change in water levels, measurements of land subsidence, and location of earth fissures. A section showing land subsidence between Casa Grande and the Picacho Peak Interchange also is included. Scale 1:250,000. (Woodard-USGS)

  5. Long-distance magma transport from arc volcanoes inferred from the submarine eruptive fissures offshore Izu-Oshima volcano, Izu-Bonin arc

    NASA Astrophysics Data System (ADS)

    Ishizuka, Osamu; Geshi, Nobuo; Kawanabe, Yoshihisa; Ogitsu, Itaru; Taylor, Rex N.; Tuzino, Taqumi; Sakamoto, Izumi; Arai, Kohsaku; Nakano, Shun

    2014-09-01

    Long-distance lateral magma transport away from volcanic centers in island arcs is emerging as a common phenomenon where the regional stress regime is favorable. It should also be recognized as an important factor in the construction and growth of island arcs, and a potential trigger for devastating eruptions. In this contribution, we report on recent investigations into the magma dynamics of Izu-Oshima volcano, an active basaltic volcano with an extensive fissure system. Izu-Oshima is flanked by numerous, subparallel NW-SE trending submarine ridges extending up to 22 km to the NW and the SE from the central vent. During a recent submersible survey we have identified that these ridges are fissures which erupted basaltic spatter and lava flows. Furthermore, lavas are petrographically similar along each ridge, while there are noticeable differences between ridges. The subparallel ridges are observed to transect a series of seamounts - the Izu-Tobu monogenetic volcanoes - which are dispersed across this area of the rear-arc. However, there are consistent petrographic and chemical differences between these seamounts and the ridges, indicating that they have different magma sources, yet, they are essentially bounding each other in dive tracks. The most appropriate scenario for their development is one where the Izu-Tobu Volcanoes are fed by an "in-situ" underlying source, while the NW-SE ridges are fed by lateral magma transport from Izu-Oshima. Magma erupted from each ridge is of a consistent geochemistry along its length, but has experienced crystal fractionation and some plagioclase accumulation. Compositions of the ridges are also very similar to lavas from the subaerial cones that can be traced down the flanks of Izu-Oshima. This implies that pairs of subaerial cones and submarine ridges represent the locus of magma transport events away from the storage system beneath Izu-Oshima. Hence, magma from this crustal reservoir moved upward to feed the on-edifice cones

  6. Automatic venting valve for gas storage tank

    SciTech Connect

    Johnson, H.

    1986-12-02

    A control valve is described for blocking atmospheric venting of gas fumes contained within a gasoline storage tank during tanker refill operations. The gasoline tank includes a venting tube coupled to open space within the top of the tank to provide air intake for pressure equalization as gasoline is gradually removed from the tank, the control valve comprising: a. a rigid, tubular valve casing having a top opening, a bottom opening and a flow channel therebetween; b. means for attaching the bottom end of the casing to an upper end of the venting tube such that the valve flow channel forms a continuation venting path for the venting tube; c. first and second valve seats and an intermediate seating member coupled to the casing and at least partially contained within the flow channel. The seating member is configured in shape and size to form restricted air space between the seating member and a surrounding wall of the flow channel to be reversibly displaceable in response to fume exhaust expelled during refill operations.

  7. Why does a mature volcano need new vents? The case of the New Southeast Crater at Etna

    NASA Astrophysics Data System (ADS)

    Acocella, Valerio; Neri, Marco; Behncke, Boris; Bonforte, Alessandro; Del Negro, Ciro; Ganci, Gaetana

    2016-06-01

    Mature volcanoes usually erupt from a persistent summit crater. Permanent shifts in vent location are expected to occur after significant structural variations and are seldom documented. Here we provide such an example that recently occurred at Etna. Eruptive activity at Mount Etna during 2007 focused at the Southeast Crater (SEC), the youngest (formed in 1971) and most active of the four summit craters, and consisted of six paroxysmal episodes. The related erupted volumes, determined by field-based measurements and radiant heat flux curves measured by satellite, totalled 8.67 x 106 m3. The first four episodes occurred, between late-March and early-May, from the summit of the SEC and short fissures on its flanks. The last two episodes occurred, in September and November, from a new vent ("pit crater" or "proto-NSEC") at the SE base of the SEC cone; this marked the definitive demise of the old SEC and the shift to the new vent. The latter, fed by NW-SE striking dikes propagating from the SEC conduit, formed since early 2011 an independent cone (the New Southeast Crater, or "NSEC") at the base of the SEC. Detailed geodetic reconstruction and structural field observations allow defining the surface deformation pattern of Mount Etna in the last decade. These suggest that the NSEC developed under the NE-SW trending tensile stresses on the volcano summit promoted by accelerated instability of the NE flank of the volcano during inflation periods. The development of the NSEC is not only important from a structural point of view, as its formation may also lead to an increase in volcanic hazard. The case of the NSEC at Etna here reported shows how flank instability may control the distribution and impact of volcanism, including the prolonged shift of the summit vent activity in a mature volcano.

  8. Spatial Compilation of Holocene Volcanic Vents in the Western Conterminous United States

    NASA Astrophysics Data System (ADS)

    Ramsey, D. W.; Siebert, L.

    2015-12-01

    A spatial compilation of all known Holocene volcanic vents in the western conterminous United States has been assembled. This compilation records volcanic vent location (latitude/longitude coordinates), vent type (cinder cone, dome, etc.), geologic map unit description, rock type, age, numeric age and reference (if dated), geographic feature name, mapping source, and, where available, spatial database source. Primary data sources include: USGS geologic maps, USGS Data Series, the Smithsonian Global Volcanism Program (GVP) catalog, and published journal articles. A total of 726 volcanic vents have been identified from 45 volcanoes or volcanic fields spanning ten states. These vents are found along the length of the Cascade arc in the Pacific Northwest, widely around the Basin and Range province, and at the southern margin of the Colorado Plateau into New Mexico. The U.S. Geological Survey (USGS) National Volcano Early Warning System (NVEWS) identifies 28 volcanoes and volcanic centers in the western conterminous U.S. that pose moderate, high, or very high threats to surrounding communities based on their recent eruptive histories and their proximity to vulnerable people, property, and infrastructure. This compilation enhances the understanding of volcano hazards that could threaten people and property by providing the context of where Holocene eruptions have occurred and where future eruptions may occur. Locations in this compilation can be spatially compared to located earthquakes, used as generation points for numerical hazard models or hazard zonation buffering, and analyzed for recent trends in regional volcanism and localized eruptive activity.

  9. Medium Fidelity Simulation of Oxygen Tank Venting

    NASA Technical Reports Server (NTRS)

    Sweet, Adam; Kurien, James; Lau, Sonie (Technical Monitor)

    2001-01-01

    The item to he cleared is a medium-fidelity software simulation model of a vented cryogenic tank. Such tanks are commonly used to transport cryogenic liquids such as liquid oxygen via truck, and have appeared on liquid-fueled rockets for decades. This simulation model works with the HCC simulation system that was developed by Xerox PARC and NASA Ames Research Center. HCC has been previously cleared for distribution. When used with the HCC software, the model generates simulated readings for the tank pressure and temperature as the simulated cryogenic liquid boils off and is vented. Failures (such as a broken vent valve) can be injected into the simulation to produce readings corresponding to the failure. Release of this simulation will allow researchers to test their software diagnosis systems by attempting to diagnose the simulated failure from the simulated readings. This model does not contain any encryption software nor can it perform any control tasks that might be export controlled.

  10. Bioremediated soil venting of light hydrocarbons

    SciTech Connect

    Ostendorf, D.W.; Kampbell, D.H.

    1990-01-01

    The effectiveness and feasibility of bioremediated soil venting of light hydrocarbons in the unsaturated zone was investigated. Degradation mechanics were considered as a one dimensional balance of storage, linear sorption, vertical advection, and Michaelis-Menton kinetics. The resulting analytical solution was tested successfully against field performance data of an unsaturated clay soil bioreactor for a propellant waste gas mixture of propane, n-butane, and isobutane. A series of venting simulations was run to assess the biodegradation of vapors above an aviation gasoline spill in sandy soil at Traverse City, Michigan, based on field and microcosm estimates of the kinetic parameters. Acclimated, nutrient rich soil effectively and feasibly reduced effluent vapor concentration from the strong influent concentration associated with dispersed residual gasoline in the contaminated capillary fringe. Aggregated residual contamination required a stronger airflow for a longer duration while natural kinetics were too slow for feasible and effective treatment by bioremediated soil venting at Traverse City.

  11. Geological and geochemical controls on the distribution of Alviniconcha vent snail symbioses: Have we finally linked mantle to microbe? (Invited)

    NASA Astrophysics Data System (ADS)

    Girguis, P. R.; Beinart, R.; Sanders, J.; Seewald, J.

    2010-12-01

    Gastropods of the genus Alviniconcha are found at hydrothermal vent fields in the Western Pacific, and have been reported to associate with either γ- or ɛ-Proteobacterial endosymbionts. These symbionts harness energy from the oxidation of chemicals in vent fluid to fix inorganic carbon and are the primary source of nutrition for the holobiont. An extensive sampling effort during a recent expedition to the Eastern Lau Spreading Center (ELSC) has revealed that Alviniconcha host both previously observed symbiont types, as well as an additional γ- proteobacterial symbiont. Specifically, we collected 266 Alviniconcha individuals from four vent fields along the spreading center (30-140km apart) which span the north-south transition from fast spreading, basalt-hosted to slower spreading, andesite-hosted fields. Vent fluids from each field were also analyzed for the abundances of aqueous volatile and non-volatile species. The symbionts of all collected Alviniconcha were genotyped using restriction fragment length polymorphism analysis as well as quantitative PCR. Individuals were found to primarily host one of the three symbiont genotypes (two γ- and one ɛ-Proteobacteria). Notably, we found that the two northern-most sites (basalt-hosted vents) were greatly dominated by individuals with the ɛ-Proteobacterial symbiont, while the two southern sites (andesite-hosted vents) were dominated by individuals hosting one of the two γ-Proteobacterial symbionts. This pattern corresponds to differences in the aqueous chemistry of the vent fluids along the spreading center. In particular, we have measured higher concentrations of hydrogen and hydrogen sulfide in the vent fluids at the northern sites than in the fluids of the southern sites. We posit that vent chemistry -which is influenced by subsurface water-rock interactions- may be influencing the dominance of each symbiont type along the ELSC. The putative implications for the role that geology and geochemistry plays in

  12. An experimental study on fracture mechanical behavior of rock-like materials containing two unparallel fissures under uniaxial compression

    NASA Astrophysics Data System (ADS)

    Huang, Yan-Hua; Yang, Sheng-Qi; Tian, Wen-Ling; Zeng, Wei; Yu, Li-Yuan

    2016-06-01

    Strength and deformability characteristics of rock with pre-existing fissures are governed by cracking behavior. To further research the effects of pre-existing fissures on the mechanical properties and crack coalescence process, a series of uniaxial compression tests were carried out for rock-like material with two unparallel fissures. In the present study, cement, quartz sand, and water were used to fabricate a kind of brittle rock-like material cylindrical model specimen. The mechanical properties of rock-like material specimen used in this research were all in good agreement with the brittle rock materials. Two unparallel fissures (a horizontal fissure and an inclined fissure) were created by inserting steel during molding the model specimen. Then all the pre-fissured rock-like specimens were tested under uniaxial compression by a rock mechanics servo-controlled testing system. The peak strength and Young's modulus of pre-fissured specimen all first decreased and then increased when the fissure angle increased from 0° to 75°. In order to investigate the crack initiation, propagation and coalescence process, photographic monitoring was adopted to capture images during the entire deformation process. Moreover, acoustic emission (AE) monitoring technique was also used to obtain the AE evolution characteristic of pre-fissured specimen. The relationship between axial stress, AE events, and the crack coalescence process was set up: when a new crack was initiated or a crack coalescence occurred, the corresponding axial stress dropped in the axial stress-time curve and a big AE event could be observed simultaneously. Finally, the mechanism of crack propagation under microscopic observation was discussed. These experimental results are expected to increase the understanding of the strength failure behavior and the cracking mechanism of rock containing unparallel fissures.

  13. A polarized light and scanning electron microscopic study of human fissure and lingual enamel of unerupted mandibular third molars.

    PubMed

    Ekstrand, K; Holmen, L; Qvortrup, K

    1999-01-01

    Using histological and ultrastructural techniques the aims of this study were to investigate whether the mineralization pattern and surface microanatomy of the caries-susceptible fissure enamel were different from those on the caries-inactive lingual surface. The material consisted of 31 unerupted third mandibular molars. The specimens were initially grouped into four categories: (1) without, (2) with initial, (3) with almost completed and (4) with completed root formation. One ground section with fissure-like morphology was selected from each tooth. Using water as a medium the observed birefringence was negative along the lingual and fissure transverses in specimens with almost completed and with completed root formation, while the observed birefringence was positive at different distances in the enamel in sections representing less maturation stages. Qualitative imbibition studies revealed hypomineralized enamel in the lower part of the fissures in specimens representing almost and completed root formation. Imbibed in quinoline, parts of the hypomineralized enamel behaved like a molecular sieve due to the presence of micropores, indicating that the structural arrangement is different from that in the enamel adjacent to this areas. After division of the sections into a lingual and a buccal part, SEM features were described from lower and upper parts of the buccal fissure wall and on lingual enamel in the area corresponding to the bottom part of the fissure. The surface microanatomy varied greatly. Negative developmental irregularities such as fissures and holes were associated with the immature enamel, while matured enamel - particularly fissures - housed many positive developmental irregularities such as enamel caps and protrusions. The crystal size in the mature specimens appeared smaller and more uniform than the crystals from the immature specimens. Apart from the occurrence of hypomineralized enamel in fissures and numerous positive developmental

  14. The effect of CT technical factors on quantification of lung fissure integrity

    NASA Astrophysics Data System (ADS)

    Chong, D.; Brown, M. S.; Ochs, R.; Abtin, F.; Brown, M.; Ordookhani, A.; Shaw, G.; Kim, H. J.; Gjertson, D.; Goldin, J. G.

    2009-02-01

    A new emphysema treatment uses endobronchial valves to perform lobar volume reduction. The degree of fissure completeness may predict treatment efficacy. This study investigated the behavior of a semiautomated algorithm for quantifying lung fissure integrity in CT with respect to reconstruction kernel and dose. Raw CT data was obtained for six asymptomatic patients from a high-risk population for lung cancer. The patients were scanned on either a Siemens Sensation 16 or 64, using a low-dose protocol of 120 kVp, 25 mAs. Images were reconstructed using kernels ranging from smooth to sharp (B10f, B30f, B50f, B70f). Research software was used to simulate an even lower-dose acquisition of 15 mAs, and images were generated at the same kernels resulting in 8 series per patient. The left major fissure was manually contoured axially at regular intervals, yielding 37 contours across all patients. These contours were read into an image analysis and pattern classification system which computed a Fissure Integrity Score (FIS) for each kernel and dose. FIS values were analyzed using a mixed-effects model with kernel and dose as fixed effects and patient as random effect to test for difference due to kernel and dose. Analysis revealed no difference in FIS between the smooth kernels (B10f, B30f) nor between sharp kernels (B50f, B70f), but there was a significant difference between the sharp and smooth groups (p = 0.020). There was no significant difference in FIS between the two low-dose reconstructions (p = 0.882). Using a cutoff of 90%, the number of incomplete fissures increased from 5 to 10 when the imaging protocol changed from B50f to B30f. Reconstruction kernel has a significant effect on quantification of fissure integrity in CT. This has potential implications when selecting patients for endobronchial valve therapy.

  15. Conversion degree, microhardness, microleakage and fluoride release of different fissure sealants.

    PubMed

    Kuşgöz, Adem; Tüzüner, Tamer; Ulker, Mustafa; Kemer, Bariş; Saray, Onur

    2010-11-01

    The purpose of this study was to determine the degree of conversion (DC), microhardness, microleakage and fluoride release of a nano-filled resin based fissure sealant (Grandio Seal, GS) and compare it with an un-filled resin based fissure sealant (Clinpro, CL) and a glass-ionomer based fissure sealant (Fuji Triage, FT). Disk shaped specimens were prepared from tested fissure sealants to determine the DC, Vicker hardness (VHN) and fluoride release (FR). The DC and VHN of each material was evaluated after 24 h. The cumulative fluoride concentrations were evaluated at 1 h, 6 h, 12 h, 1, 7, 15 and 30 days. For microleakage evaluation, fissure sealants were applied to the etched and dried enamel surfaces of sound third molar teeth according to the manufacturer's instructions (n=10). After the thermocycling and mechanical loading procedures, microleakage assessments were carried out. Data were analyzed using one-way ANOVA followed by a post hoc Tukey test, the Kruskal Wallis and Mann-Whitney U test (p<0.05). Results revealed differences regarding DC between all groups: FT (89%) > GS (55.02%) > CL (%51.10) (p<0.05). The VHN values were significantly different among all groups in the following order: GS > FT > CL (p<0.05). FT exhibited significantly higher microleakage scores compared to the CL and GS sealants (p<0.05). The FR of FT was significantly greater than CL and GS (p<0.05). Nano-filled resin based sealant can be used as an alternative to other fissure sealant materials because of its superior hardness results and feasible sealing ability.

  16. Anthropometric Analysis of Palpebral Fissure Dimensions and its Position in South Indian Ethnic Adults

    PubMed Central

    Vasanthakumar, P.; Kumar, Pramod; Rao, Mohandas

    2013-01-01

    Objectives The morphology and anatomical relationship of periorbital features vary according to age, sex and ethnicity. Standard database regarding periorbital region is available for other ethnic groups. Since there is no data available in the literature, specifically for south Indian ethnic adults, the present study was carried out to determine the normal average values for South Indian ethnic population related to gender. Methods Anthropometric measurements of both eyes were done on standardized frontal view photograph of 200 South Indian ethnic adults aged 18 to 26 years. Parameters included were palpebral fissure width (PFW), palpebral fissure height (PFH), palpebral fissure inclination (PFI), outercanthal distance (OCD), interpupillary distance (IPD), intercanthal distance (ICD) and comparisons were made between the genders using the independent t test. Results Significant sexual dimorphism was noted in the given parameters. Palpebral fissure width (male: 31.08 mm; female: 29.90 mm), palpebral fissure inclination (male: 5.053°; female: 6.102°), outercanthal distance (male: 95.55 mm; female: 92.44 mm) and interpupillary distance (male: 66.72 mm; female: 62.59 mm). The palpebral fissure height (male: 11.30 mm; female: 11.58 mm) and intercanthal distance (male: 34.27 mm; female: 33.41 mm) showed no significant sexual differences. Conclusion Statistically significant differences were found between South Indian ethnic males and female in certain key parameters. The present study suggests that ethnicity and gender should be considered in orbital surgery. To individualize the treatment planning and diagnosis, it is important for the surgeons to have knowledge of these local norms. PMID:23386941

  17. Vent conditions for expected eruptions at Vesuvius

    NASA Astrophysics Data System (ADS)

    Papale, Paolo; Longo, Antonella

    2008-12-01

    Determining consistent sets of vent conditions for next expected eruptions at Vesuvius is crucial for the simulation of the sub-aerial processes originating the volcanic hazard and the eruption impact. Here we refer to the expected eruptive scales and conditions defined in the frame of the EC Exploris project, and simulate the dynamics of magma ascent along the volcanic conduit for sub-steady phases of next eruptions characterized by intensities of the Violent Strombolian (VS), Sub-Plinian 2 (SP2), and Sub-Plinian 1 (SP1) scale. Sets of conditions for the simulations are determined on the basis of the bulk of knowledge on the past history of Vesuvius [Cioni, R., Bertagnini, A., Santacroce, R., Andronico, D., Explosive activity and eruption scenarios at Somma-Vesuvius (Italy): towards a new classification scheme. Journal of Volcanology and Geothermal Research, this issue.]. Volatile contents (H 2O and CO 2) are parameterized in order to account for the uncertainty in their expected amounts for a next eruption. In all cases the flow in the conduit is found to be choked, with velocities at the conduit exit or vent corresponding to the sonic velocity in the two-phase non-equilibrium magmatic mixture. Conduit diameters and vent mixture densities are found to display minimum overlapping between the different eruptive scales, while exit gas and particle velocities, as well as vent pressures, largely overlap. Vent diameters vary from as low as about 5 m for VS eruptions, to 35-55 m for the most violent SP1 eruption scale. Vent pressures can be as low as less than 1 MPa for the lowest volatile content employed of 2 wt.% H 2O and no CO 2, to 7-8 MPa for highest volatile contents of 5 wt.% H 2O and 2 wt.% CO 2 and large eruptive scales. Gas and particle velocities at the vent range from 100-250 m/s, with a tendency to decrease, and to increase the mechanical decoupling between the phases, with increasing eruptive scale. Except for velocities, all relevant vent quantities are

  18. Vented Cavity Radiant Barrier Assembly And Method

    DOEpatents

    Dinwoodie, Thomas L.; Jackaway, Adam D.

    2000-05-16

    A vented cavity radiant barrier assembly (2) includes a barrier (12), typically a PV module, having inner and outer surfaces (18, 22). A support assembly (14) is secured to the barrier and extends inwardly from the inner surface of the barrier to a building surface (14) creating a vented cavity (24) between the building surface and the barrier inner surface. A low emissivity element (20) is mounted at or between the building surface and the barrier inner surface. At least part of the cavity exit (30) is higher than the cavity entrance (28) to promote cooling air flow through the cavity.

  19. Double-porosity models for a fissured groundwater reservoir with fracture skin.

    USGS Publications Warehouse

    Moench, A.F.

    1984-01-01

    Theories of flow to a well in a double-porosity groundwater reservoir are modified to incorporate effects of a thin layer of low-permeability material or fracture skin that may be present at fracture-block interfaces as a result of mineral deposition or alteration. The commonly used theory for flow in double-porosity formations that is based upon the assumption of pseudo-steady state block-to-fissure flow is shown to be a special case of the theory presented in this paper. The latter is based on the assumption of transient block-to-fissure flow with fracture skin.-from Author

  20. [Saccular aneurysm of the azygos vein in a patient with azygos accessory fissure].

    PubMed

    Córdoba Rovira, S M; Guedea Martin, A; Salvador Adell, I; Elias Artiga, J

    2015-01-01

    The saccular aneurysm of the azygos vein is an extremely rare condition, which when located in the path of an accesory pulmonary fissure, becomes a diagnostic challenge because it can be mistaken for tumors arising from the accesory pleura, like solitary fibrous tumor of the pleura or mesothelioma. The diagnosis should ideally be done by non-invasive methods such as CT or MR angiographic technique in multiple phases, thus avoiding unnecessary surgical intervention. This case is exceptional because, to our knowledge, it is the first to report both concomitant clinical situations, an aneurysm of the azygos vein in the pathway of its accessory fissure.

  1. Quantifying diffuse and discrete venting at the Tour Eiffel vent site, Lucky Strike hydrothermal field

    NASA Astrophysics Data System (ADS)

    Mittelstaedt, Eric; EscartíN, Javier; Gracias, Nuno; Olive, Jean-Arthur; Barreyre, Thibaut; Davaille, Anne; Cannat, Mathilde; Garcia, Rafael

    2012-04-01

    The relative heat carried by diffuse versus discrete venting of hydrothermal fluids at mid-ocean ridges is poorly constrained and likely varies among vent sites. Estimates of the proportion of heat carried by diffuse flow range from 0% to 100% of the total axial heat flux. Here, we present an approach that integrates imagery, video, and temperature measurements to accurately estimate this partitioning at a single vent site, Tour Eiffel in the Lucky Strike hydrothermal field along the Mid-Atlantic Ridge. Fluid temperatures, photographic mosaics of the vent site, and video sequences of fluid flow were acquired during the Bathyluck'09 cruise (Fall, 2009) and the Momarsat'10 cruise (Summer, 2010) to the Lucky Strike hydrothermal field by the ROV Victor6000 aboard the French research vessel the "Pourquoi Pas"? (IFREMER, France). We use two optical methods to calculate the velocities of imaged hydrothermal fluids: (1) for diffuse venting, Diffuse Flow Velocimetry tracks the displacement of refractive index anomalies through time, and (2) for discrete jets, Particle Image Velocimetry tracks eddies by cross-correlation of pixel intensities between subsequent images. To circumvent video blurring associated with rapid velocities at vent orifices, exit velocities at discrete vents are calculated from the best fit of the observed velocity field to a model of a steady state turbulent plume where we vary the model vent radius and fluid exit velocity. Our results yield vertical velocities of diffuse effluent between 0.9 cm s-1 and 11.1 cm s-1 for fluid temperatures between 3°C and 33.5°C above that of ambient seawater, and exit velocities of discrete jets between 22 cm s-1 and 119 cm s-1 for fluid temperatures between 200°C and 301°C above ambient seawater. Using the calculated fluid velocities, temperature measurements, and photo mosaics of the actively venting areas, we calculate a heat flux due to diffuse venting from thin fractures of 3.15 ± 2.22 MW, discrete venting of

  2. 30 CFR 77.304 - Explosion release vents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Dryers § 77.304 Explosion release vents. Drying chambers, dry-dust collectors, ductwork connecting dryers to dust collectors, and ductwork between dust collectors and discharge stacks shall be protected with... vent dry dust collectors....

  3. 46 CFR 153.463 - Vent system discharges.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Requirements for Flammable Or Combustible Cargoes § 153.463 Vent system discharges. The discharge of a venting... to carry a flammable or combustible cargo; and (b) Table 1 requires the cargo to have a PV...

  4. 46 CFR 153.463 - Vent system discharges.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Requirements for Flammable Or Combustible Cargoes § 153.463 Vent system discharges. The discharge of a venting... to carry a flammable or combustible cargo; and (b) Table 1 requires the cargo to have a PV...

  5. Breeding for rice fissure resistance made possible through development of a new selection technique and identification of molecular gene tags

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Value: One of the primary causes of rice grain breakage during milling is fissuring, or cracking, of the rice before it enters the mill. Any reduction in kernel fissuring can result in direct increases in profit for both producers and millers. For a producer yielding 7,000 lb/A paddy, even a small (...

  6. 40 CFR 63.1321 - Batch process vents provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Batch process vents provisions. 63... Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins § 63.1321 Batch process vents provisions. (a) Batch process vents. Except as specified in paragraphs (b) through (d) of this...

  7. 40 CFR 63.1406 - Reactor batch process vent provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 12 2012-07-01 2011-07-01 true Reactor batch process vent provisions... § 63.1406 Reactor batch process vent provisions. (a) Emission standards. Owners or operators of reactor batch process vents located at new or existing affected sources shall comply with paragraph (a)(1) or...

  8. 40 CFR 63.1406 - Reactor batch process vent provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 12 2014-07-01 2014-07-01 false Reactor batch process vent provisions... Resins § 63.1406 Reactor batch process vent provisions. (a) Emission standards. Owners or operators of reactor batch process vents located at new or existing affected sources shall comply with paragraph...

  9. 40 CFR 63.1321 - Batch process vents provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 12 2014-07-01 2014-07-01 false Batch process vents provisions. 63... Batch process vents provisions. (a) Batch process vents. Except as specified in paragraphs (b) through (d) of this section, owners and operators of new and existing affected sources with batch...

  10. 40 CFR 63.1406 - Reactor batch process vent provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Reactor batch process vent provisions... § 63.1406 Reactor batch process vent provisions. (a) Emission standards. Owners or operators of reactor batch process vents located at new or existing affected sources shall comply with paragraph (a)(1) or...

  11. 40 CFR 63.1321 - Batch process vents provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 12 2012-07-01 2011-07-01 true Batch process vents provisions. 63.1321... Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins § 63.1321 Batch process vents provisions. (a) Batch process vents. Except as specified in paragraphs (b) through (d) of this...

  12. 40 CFR 63.1406 - Reactor batch process vent provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Reactor batch process vent provisions... § 63.1406 Reactor batch process vent provisions. (a) Emission standards. Owners or operators of reactor batch process vents located at new or existing affected sources shall comply with paragraph (a)(1) or...

  13. 40 CFR 63.1321 - Batch process vents provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Batch process vents provisions. 63.1321... Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins § 63.1321 Batch process vents provisions. (a) Batch process vents. Except as specified in paragraphs (b) through (d) of this...

  14. 40 CFR 63.1406 - Reactor batch process vent provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 12 2013-07-01 2013-07-01 false Reactor batch process vent provisions... Resins § 63.1406 Reactor batch process vent provisions. (a) Emission standards. Owners or operators of reactor batch process vents located at new or existing affected sources shall comply with paragraph...

  15. "Venting" in the Workplace: An Ethnographic Study among Resident Assistants.

    ERIC Educational Resources Information Center

    Burchard, Brendon

    The term "venting" has been used interchangeably with negatively-connotated words like "outburst,""bitching,""complaining," and with more functional words like "disclosing." A literature review of venting showed that researchers have approached the term from multiple perspectives. Because of the ambiguity of what venting is or is not, why it is…

  16. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... manufactured home. (d) Venting system terminations shall be not less than three feet from any motor-driven air... HOUSING AND URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Heating, Cooling and Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required...

  17. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... manufactured home. (d) Venting system terminations shall be not less than three feet from any motor-driven air... HOUSING AND URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Heating, Cooling and Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required...

  18. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... manufactured home. (d) Venting system terminations shall be not less than three feet from any motor-driven air... HOUSING AND URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Heating, Cooling and Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required...

  19. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... manufactured home. (d) Venting system terminations shall be not less than three feet from any motor-driven air... HOUSING AND URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Heating, Cooling and Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required...

  20. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... manufactured home. (d) Venting system terminations shall be not less than three feet from any motor-driven air... HOUSING AND URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Heating, Cooling and Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required...

  1. 46 CFR 153.358 - Venting system flow capacity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Venting system flow capacity. 153.358 Section 153.358 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS... Venting Systems § 153.358 Venting system flow capacity. (a) The cross-sectional flow area of any...

  2. 46 CFR 153.358 - Venting system flow capacity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Venting system flow capacity. 153.358 Section 153.358 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS... Venting Systems § 153.358 Venting system flow capacity. (a) The cross-sectional flow area of any...

  3. 46 CFR 153.358 - Venting system flow capacity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Venting system flow capacity. 153.358 Section 153.358 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS... Venting Systems § 153.358 Venting system flow capacity. (a) The cross-sectional flow area of any...

  4. 46 CFR 153.358 - Venting system flow capacity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Venting system flow capacity. 153.358 Section 153.358 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Venting Systems § 153.358 Venting system...

  5. 46 CFR 56.50-85 - Tank-vent piping.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... applies to vents for all independent, fixed, non-pressure tanks or containers or for spaces in which... liquids, such as lubricating oil, may terminate in the machinery space, provided— (i) The vents are... combustible liquids are not heated; and (iii) The vents terminate above the deep load waterline if the...

  6. 46 CFR 56.50-85 - Tank-vent piping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... applies to vents for all independent, fixed, non-pressure tanks or containers or for spaces in which... liquids, such as lubricating oil, may terminate in the machinery space, provided— (i) The vents are... combustible liquids are not heated; and (iii) The vents terminate above the deep load waterline if the...

  7. 46 CFR 56.50-85 - Tank-vent piping.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... applies to vents for all independent, fixed, non-pressure tanks or containers or for spaces in which... liquids, such as lubricating oil, may terminate in the machinery space, provided— (i) The vents are... combustible liquids are not heated; and (iii) The vents terminate above the deep load waterline if the...

  8. 46 CFR 56.50-85 - Tank-vent piping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... applies to vents for all independent, fixed, non-pressure tanks or containers or for spaces in which... liquids, such as lubricating oil, may terminate in the machinery space, provided— (i) The vents are... combustible liquids are not heated; and (iii) The vents terminate above the deep load waterline if the...

  9. 14 CFR 121.261 - Vent and drain lines.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Vent and drain lines. 121.261 Section 121... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.261 Vent and drain lines. All vent and drain lines and their fittings, that are located in a designated fire...

  10. 14 CFR 27.975 - Fuel tank vents.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank vents. 27.975 Section 27.975... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.975 Fuel tank vents. (a) Each fuel tank... flight conditions. Each vent must minimize the probability of stoppage by dirt or ice. (b) The...

  11. 40 CFR 65.143 - Closed vent systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Process § 65.143 Closed vent systems. (a) Closed vent system equipment and operating requirements. The... storage vessel, process vent, transfer rack, or equipment leaks. (1) Collection of emissions. Each closed... operate a flow indicator that takes a reading at least once every 15 minutes. Records shall be...

  12. 14 CFR 34.11 - Standard for fuel venting emissions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Engine Fuel Venting Emissions (New and In-Use Aircraft Gas Turbine Engines) § 34.11 Standard for fuel venting emissions. (a) No... turbine engine subject to the subpart. This paragraph is directed at the elimination of...

  13. 14 CFR 34.11 - Standard for fuel venting emissions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Engine Fuel Venting Emissions (New and In-Use Aircraft Gas Turbine Engines) § 34.11 Standard for fuel venting emissions. (a) No... turbine engine subject to the subpart. This paragraph is directed at the elimination of...

  14. 14 CFR 34.11 - Standard for fuel venting emissions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Engine Fuel Venting Emissions (New and In-Use Aircraft Gas Turbine Engines) § 34.11 Standard for fuel venting emissions. (a) No... turbine engine subject to the subpart. This paragraph is directed at the elimination of...

  15. 40 CFR 63.1408 - Aggregate batch vent stream provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 12 2013-07-01 2013-07-01 false Aggregate batch vent stream provisions... Resins § 63.1408 Aggregate batch vent stream provisions. (a) Emission standards. Owners or operators of aggregate batch vent streams at a new or existing affected source shall comply with either paragraph...

  16. 40 CFR 63.1408 - Aggregate batch vent stream provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Aggregate batch vent stream provisions... § 63.1408 Aggregate batch vent stream provisions. (a) Emission standards. Owners or operators of aggregate batch vent streams at a new or existing affected source shall comply with either paragraph...

  17. 40 CFR 63.1408 - Aggregate batch vent stream provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 12 2014-07-01 2014-07-01 false Aggregate batch vent stream provisions... Resins § 63.1408 Aggregate batch vent stream provisions. (a) Emission standards. Owners or operators of aggregate batch vent streams at a new or existing affected source shall comply with either paragraph...

  18. 40 CFR 63.1408 - Aggregate batch vent stream provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Aggregate batch vent stream provisions... § 63.1408 Aggregate batch vent stream provisions. (a) Emission standards. Owners or operators of aggregate batch vent streams at a new or existing affected source shall comply with either paragraph...

  19. 40 CFR 63.1408 - Aggregate batch vent stream provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 12 2012-07-01 2011-07-01 true Aggregate batch vent stream provisions... § 63.1408 Aggregate batch vent stream provisions. (a) Emission standards. Owners or operators of aggregate batch vent streams at a new or existing affected source shall comply with either paragraph...

  20. 14 CFR 34.11 - Standard for fuel venting emissions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Engine Fuel Venting Emissions (New and In-Use Aircraft Gas Turbine Engines) § 34.11 Standard for fuel venting emissions. (a) No... discharge to the atmosphere of fuel drained from fuel nozzle manifolds after engines are shut down and...

  1. 14 CFR 27.975 - Fuel tank vents.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel tank vents. 27.975 Section 27.975... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.975 Fuel tank vents. (a) Each fuel tank... system must be designed to minimize spillage of fuel through the vents to an ignition source in the...

  2. 40 CFR 63.983 - Closed vent systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... bypass lines that could divert a vent stream to the atmosphere. (i) Properly install, maintain, and... loading arm in the rack to the atmosphere. (5) Pressure relief devices in a transfer rack's closed vent... that no pressure relief device in the transfer rack's closed vent system shall open to the...

  3. 40 CFR 63.983 - Closed vent systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... bypass lines that could divert a vent stream to the atmosphere. (i) Properly install, maintain, and... loading arm in the rack to the atmosphere. (5) Pressure relief devices in a transfer rack's closed vent... that no pressure relief device in the transfer rack's closed vent system shall open to the...

  4. 33 CFR 183.520 - Fuel tank vent systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Fuel tank vent systems. 183.520...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.520 Fuel tank vent systems. (a) Each fuel tank must have a vent system that prevents pressure in the tank from exceeding...

  5. Discovery of a black smoker vent field and vent fauna at the Arctic Mid-Ocean Ridge

    PubMed Central

    Pedersen, Rolf B.; Rapp, Hans Tore; Thorseth, Ingunn H.; Lilley, Marvin D.; Barriga, Fernando J. A. S.; Baumberger, Tamara; Flesland, Kristin; Fonseca, Rita; Früh-Green, Gretchen L.; Jorgensen, Steffen L.

    2010-01-01

    The Arctic Mid-Ocean Ridge (AMOR) represents one of the most slow-spreading ridge systems on Earth. Previous attempts to locate hydrothermal vent fields and unravel the nature of venting, as well as the provenance of vent fauna at this northern and insular termination of the global ridge system, have been unsuccessful. Here, we report the first discovery of a black smoker vent field at the AMOR. The field is located on the crest of an axial volcanic ridge (AVR) and is associated with an unusually large hydrothermal deposit, which documents that extensive venting and long-lived hydrothermal systems exist at ultraslow-spreading ridges, despite their strongly reduced volcanic activity. The vent field hosts a distinct vent fauna that differs from the fauna to the south along the Mid-Atlantic Ridge. The novel vent fauna seems to have developed by local specialization and by migration of fauna from cold seeps and the Pacific. PMID:21119639

  6. Discovery of a black smoker vent field and vent fauna at the Arctic Mid-Ocean Ridge.

    PubMed

    Pedersen, Rolf B; Rapp, Hans Tore; Thorseth, Ingunn H; Lilley, Marvin D; Barriga, Fernando J A S; Baumberger, Tamara; Flesland, Kristin; Fonseca, Rita; Früh-Green, Gretchen L; Jorgensen, Steffen L

    2010-11-23

    The Arctic Mid-Ocean Ridge (AMOR) represents one of the most slow-spreading ridge systems on Earth. Previous attempts to locate hydrothermal vent fields and unravel the nature of venting, as well as the provenance of vent fauna at this northern and insular termination of the global ridge system, have been unsuccessful. Here, we report the first discovery of a black smoker vent field at the AMOR. The field is located on the crest of an axial volcanic ridge (AVR) and is associated with an unusually large hydrothermal deposit, which documents that extensive venting and long-lived hydrothermal systems exist at ultraslow-spreading ridges, despite their strongly reduced volcanic activity. The vent field hosts a distinct vent fauna that differs from the fauna to the south along the Mid-Atlantic Ridge. The novel vent fauna seems to have developed by local specialization and by migration of fauna from cold seeps and the Pacific.

  7. Processes and interactions in macrofaunal assemblages at hydrothermal vents: A modeling perspective

    NASA Astrophysics Data System (ADS)

    Shea, Katriona; Metaxas, Anna; Young, Curtis R.; Fisher, Charles R.

    Our understanding of the biological assemblages at hydrothermal vents is growing rapidly, in part facilitated by the coupling of experimental and observational methods with theoretical modeling efforts. We review theoretical approaches in four main areas and link them to empirical studies of the biology of hydrothermal vent systems. First, we describe models of dispersal of vent organisms within and among vent sites. These models fall broadly into two categories: those based on larval biology and currents that predict dispersal capabilities from a source, and those using genetic data to address historical genetic links between populations. Then we discuss models for individual and population growth at a location and give examples from work in a biologically similar deep-sea environment: cold seeps. Third, we address how these two aspects can be integrated using models that couple dispersal and demography. Last, we summarize existing modeling approaches for community succession in other types of habitats, and outline the conceptual models and the sorts of data that currently exist for hydrothermal vent communities. Throughout, we also examine the use of models in improving experimental design.

  8. Electrochemical cell having improved pressure vent

    DOEpatents

    Dean, Kevin; Holland, Arthur; Fillmore, Donn

    1993-01-01

    The electrochemical cell of the instant invention includes a case having a gas outlet, one or more positive electrodes positioned within the case, one or more negative electrodes positioned within the case electrode separators positioned between the positive and negative electrodes, electrolyte positioned within the case, and a pressure vent for releasing internal pressure occurring in the case to the surrounding atmosphere. The pressure vent is affixed to the case covering the gas outlet, the pressure vent includes a vent housing having a hollow interior area in gaseous communication with the surrounding atmosphere and the interior of the case via the gas outlet, a pressure release piston positioned within the hollow interior area, the pressure release piston sized to surround the gas outlet and having a seal groove configured to encapsulate all but one surface of a seal mounted within the seal groove, leaving the non-encapsulated surface of the seal exposed, and a compression spring positioned to urge the pressure release piston to compress the seal in the seal groove and block the gas outlet in the case.

  9. Flow fields of low pressure vent exhausts

    NASA Technical Reports Server (NTRS)

    Scialdone, John J.

    1989-01-01

    The flow field produced by low pressure gas vents are described based on experimental data obtained from tests in a large vacuum chamber. The gas density, pressure, and flux at any location in the flow field are calculated based on the vent plume description and the knowledge of the flow rate and velocity of the venting gas. The same parameters and the column densities along a specified line of sight traversing the plume are also obtained and shown by a computer-generated graphical representation. The fields obtained with a radially scanning Pitot probe within the exhausting gas are described by a power of the cosine function, the mass rate and the distance from the exit port. The field measurements were made for gas at pressures ranging from 2 to 50 torr venting from pipe fittings with diameters of 3/16 inch to 1-1/2 inches I.D. (4.76 mm to 38.1 mm). The N(2) mass flow rates ranged from 2E-4 to 3.7E-1 g/s.

  10. 46 CFR 98.25-70 - Venting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Venting. 98.25-70 Section 98.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  11. 46 CFR 98.25-70 - Venting.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Venting. 98.25-70 Section 98.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  12. 46 CFR 98.25-70 - Venting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Venting. 98.25-70 Section 98.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  13. 46 CFR 98.25-70 - Venting.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Venting. 98.25-70 Section 98.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  14. 46 CFR 98.25-70 - Venting.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Venting. 98.25-70 Section 98.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  15. 49 CFR 229.95 - Venting.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Venting. 229.95 Section 229.95 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment §...

  16. 49 CFR 229.95 - Venting.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Venting. 229.95 Section 229.95 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment §...

  17. 49 CFR 229.95 - Venting.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Venting. 229.95 Section 229.95 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment §...

  18. 49 CFR 229.95 - Venting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Venting. 229.95 Section 229.95 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment §...

  19. 49 CFR 229.95 - Venting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Venting. 229.95 Section 229.95 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment §...

  20. Preoperational test report, vent building ventilation system

    SciTech Connect

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Vent Building Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides Heating, Ventilation, and Air Conditioning (HVAC) for the W-030 Ventilation Building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  1. Evidence for Hydrothermal Vents as "Biogeobatteries" (Invited)

    NASA Astrophysics Data System (ADS)

    Nielsen, M. E.; Girguis, P. R.

    2010-12-01

    Hydrothermal vents are unique systems that play an important role in oceanic biogeochemical cycles. As chemically reduced hydrothermal fluid mixes with cold oxic seawater, minerals precipitate out of solution resulting in chimney structures composed largely of metal sulfides and anhydrite. Pyrite, which is a natural semi-conductor, is the primary sulfide mineral, but other minerals within chimneys are also conductive (e.g. chalcopyrite, wurtzite, and some iron oxides). Sulfide chimneys are also known to host an extensive endolithic microbial community. Accordingly, submarine hydrothermal systems appear to be examples of biogeobatteries, wherein conductive mineral assemblages span naturally occuring redox gradients and enable anaerobic microbes to access oxygen as an oxidant via extracellular electron transfer (or EET). To test this hypothesis, we ran a series of electrochemical laboratory experiments in which pyrite was used as an anode (in a vessel flushed with hydrothermal-like fluid). When placed in continuity with a carbon fiber cathode, pyrite was found to accept and conduct electrons from both abiotic and biological processes (microbial EET). Specifically, electrical current increased 4-fold (5 nA/m2 to 20 nA/m2) in response to inoculation with a slurry prepared from a hydrothermal vent sample. Inspection of the pyrite anode with SEM revealed ubiquitous coverage by microbes. DNA was extracted from the anodes and the inoculum, and was subjected to pyrosequencing to examine prokaryotic diversity. These data suggest that key microbial phylotypes were enriched upon the pyrite, implicating them in EET. In addition, we deployed an in situ experiment based on microbial fuel cell architecture with a graphite anode inserted into a vent wall coupled to a carbon fiber cathode outside the vent. We observed current production over the course of one year, implying microbial EET in situ. Via pyrosequencing, we observed that the microbial community on the anode was

  2. An Unusual Stress Metabolite from a Hydrothermal Vent Fungus Aspergillus sp. WU 243 Induced by Cobalt.

    PubMed

    Ding, Chihong; Wu, Xiaodan; Auckloo, Bibi Nazia; Chen, Chen-Tung Arthur; Ye, Ying; Wang, Kuiwu; Wu, Bin

    2016-01-01

    A novel hybrid polyketide-terpenoid, aspergstressin (1), possessing a unique fused polycyclic structure, was induced from culture broth of strain Aspergillus sp. WU 243 by cobalt ion stimulation. The strain was isolated from the digestive gland of Xenograpsus testudinatus, a unique type of crab which dwells in the Kueishantao hydrothermal vents off Taiwan. The chemical structure and relative configuration of the stress metabolite were established by spectroscopic means. Aspergillus sp. WU 243 produced aspergstressin (1) only under cobalt stressed culture conditions. The results show that stress-driven discovery of new natural products from hydrothermal vent fungi is an effective strategy to unveil the untapped reservoir of small molecules from species found in the hydrothermal vent environment. PMID:26784166

  3. An Unusual Stress Metabolite from a Hydrothermal Vent Fungus Aspergillus sp. WU 243 Induced by Cobalt.

    PubMed

    Ding, Chihong; Wu, Xiaodan; Auckloo, Bibi Nazia; Chen, Chen-Tung Arthur; Ye, Ying; Wang, Kuiwu; Wu, Bin

    2016-01-01

    A novel hybrid polyketide-terpenoid, aspergstressin (1), possessing a unique fused polycyclic structure, was induced from culture broth of strain Aspergillus sp. WU 243 by cobalt ion stimulation. The strain was isolated from the digestive gland of Xenograpsus testudinatus, a unique type of crab which dwells in the Kueishantao hydrothermal vents off Taiwan. The chemical structure and relative configuration of the stress metabolite were established by spectroscopic means. Aspergillus sp. WU 243 produced aspergstressin (1) only under cobalt stressed culture conditions. The results show that stress-driven discovery of new natural products from hydrothermal vent fungi is an effective strategy to unveil the untapped reservoir of small molecules from species found in the hydrothermal vent environment. PMID:26805789

  4. An Unusual Stress Metabolite from a Hydrothermal Vent Fungus Aspergillus sp. WU 243 Induced by Cobalt.

    PubMed

    Ding, Chihong; Wu, Xiaodan; Auckloo, Bibi Nazia; Chen, Chen-Tung Arthur; Ye, Ying; Wang, Kuiwu; Wu, Bin

    2016-01-16

    A novel hybrid polyketide-terpenoid, aspergstressin (1), possessing a unique fused polycyclic structure, was induced from culture broth of strain Aspergillus sp. WU 243 by cobalt ion stimulation. The strain was isolated from the digestive gland of Xenograpsus testudinatus, a unique type of crab which dwells in the Kueishantao hydrothermal vents off Taiwan. The chemical structure and relative configuration of the stress metabolite were established by spectroscopic means. Aspergillus sp. WU 243 produced aspergstressin (1) only under cobalt stressed culture conditions. The results show that stress-driven discovery of new natural products from hydrothermal vent fungi is an effective strategy to unveil the untapped reservoir of small molecules from species found in the hydrothermal vent environment.

  5. An Unusual Stress Metabolite from a Hydrothermal Vent Fungus Aspergillus sp. WU 243 Induced by Cobalt.

    PubMed

    Ding, Chihong; Wu, Xiaodan; Auckloo, Bibi Nazia; Chen, Chen-Tung Arthur; Ye, Ying; Wang, Kuiwu; Wu, Bin

    2016-01-01

    A novel hybrid polyketide-terpenoid, aspergstressin (1), possessing a unique fused polycyclic structure, was induced from culture broth of strain Aspergillus sp. WU 243 by cobalt ion stimulation. The strain was isolated from the digestive gland of Xenograpsus testudinatus, a unique type of crab which dwells in the Kueishantao hydrothermal vents off Taiwan. The chemical structure and relative configuration of the stress metabolite were established by spectroscopic means. Aspergillus sp. WU 243 produced aspergstressin (1) only under cobalt stressed culture conditions. The results show that stress-driven discovery of new natural products from hydrothermal vent fungi is an effective strategy to unveil the untapped reservoir of small molecules from species found in the hydrothermal vent environment.

  6. 49 CFR 179.300-13 - Venting, loading and unloading valves.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Venting, loading and unloading valves. 179.300-13..., loading and unloading valves. (a) Valves shall be of approved type, made of metal not subject to rapid deterioration by lading, and shall withstand tank test pressure without leakage. The valves shall be...

  7. Safety Testing of Left Ventricular Vent Valves.

    PubMed

    Gavin, Caroline; Coblentz, John; Acsell, Jeffrey R; Shackelford, Anthony G; Sistino, Joseph J

    2015-03-01

    Vent vacuum relief valves (VRVs) are used to limit the negative pressure at the ventricular vent catheter tip as well as prevent reversal of blood flow and prevention of air embolism. The purpose of this study was to evaluate the performance of three commercially available ventricular vent valves. The negative pressure at which the vent valve opened was measured at the valve inlet using high-fidelity pressure transducers. Also, the flow rate at which air entrainment occurred due to valve opening was recorded. Using a 51.5 cm column of saline, the resistance for each valve was calculated. The mean ± SD opening negative pressures were -231.3 ± 35.2 mmHg for the Quest Medical valve, -219.8 mmHg ± 17.2 for the Sorin valve, and -329.6 · 38.0 mmHg for the Terumo valve. The red Quest Medical valve opened at a lower flow (1.44 ± .03 L/min) than the dark blue Sorin valve (2.93 ± .01 L/min) and light blue LH130 Terumo valve (2.36 ± .02 L/min). The Sorin valve had the least resistance of 34.1 dyn-s/cm, followed by the Terumo LH130 valve resistance of 58.1 dyn·s/cm5, and the Quest Medical VRV-II valve with a resistance of 66.5 dyn·s/cm. We found that the valves are significantly different in the negative pressure generated. Understanding the limitations of these devices is important to reduce the occurrence of adverse events associated with venting and to select the best device for a specific clinical application.

  8. Response of rock-fissure seepage to snowmelt in Mount Taihang slope-catchment, North China.

    PubMed

    Cao, Jiansheng; Liu, Changming; Zhang, Wanjun

    2013-01-01

    The complex physiographic and hydrogeological systems of mountain terrains facilitate intense rock-fissure seepages and multi-functional ecological interactions. As mountain eco-hydrological terrains are the common water sources of river basins across the globe, it is critical to build sufficient understanding into the hydrological processes in this unique ecosystem. This study analyzes infiltration and soil/rock-fissure seepage processes from a 65 mm snowfall/melt in November 2009 in the typical granitic gneiss slope catchment in the Taihang Mountains. The snowfall, snowmelt and melt-water processes are monitored using soil-water time-domain reflectometry (TDR) probes and tipping bucket flowmeters. The results suggest that snowmelt infiltration significantly influences soil/rock water seepage in the 0-100 cm soil depth of the slope-catchment. It is not only air temperature that influences snowmelt, but also snowmelt infiltration and rock-fissure seepage. Diurnal variations in rock-fissure seepage are in close correlation with air temperature (R(2) > 0.7). Temperature also varies with soil/rock water viscosity, which element in turn influences soil/rock water flow. Invariably, water dynamics in the study area is not only a critical water supply element for domestic, industrial and agricultural uses, but also for food security and social stability.

  9. A comparison between three different pit and fissure sealants with regard to marginal integrity

    PubMed Central

    Fernandes, Kristlee Sabrin; Chalakkal, Paul; de Ataide, Ida de Noronha; Pavaskar, Rajdeep; Fernandes, Precylia Philo; Soni, Harleen

    2012-01-01

    Aim: The aim of this study is to compare the occurrence of enamel fractures, sealant fractures and marginal fissures after placement of three sealants: Helioseal F, Conseal F and Clinpro. Materials and Methods: Thirty individuals between 13 and 15 years of age, diagnosed with pit and fissure caries by visual and DIAGNOdent examination, were chosen for sealant placement on their mandibular molars. The sealants were placed at random, after which, impressions were made with polyvinyl siloxane and casts were fabricated. Dies were prepared, each of which were sputter coated with gold in order to be examined under a scanning electron microscope. The following morphologies were analyzed from dies from each of the sealant groups: Continuous margins, sealant fractures, marginal fissures and enamel fractures. After six months, they were recalled for impression making. Dies were prepared and microscopically analyzed as mentioned. Based on the time of evaluation, there were two groups: Initial group (soon after placement) and final group (after six months). Statistical analysis was done using the paired ‘t’ test and One-way analysis of variance (ANOVA). Results and Conclusions: Clinpro had the greatest fracture resistance, followed by Conseal F and Helioseal F. The occurrence of marginal fissure was found to be least with Clinpro. PMID:22557813

  10. Giant desiccation fissures on the Black Rock and Smoke Creek Deserts, Nevada

    USGS Publications Warehouse

    Willden, R.; Mabey, D.R.

    1961-01-01

    Open fissures, from 100 to several hundred feet apart, that have produced polygonal patterns on the Black Rock Desert, Nevada, are believed to be giant desiccation cracks resulting from a secular trend toward aridity in the last few decades. Similar features on the Smoke Creek Desert probably have the same origin.

  11. Influence of matrix diffusion and exchange reactions on radiocarbon ages in fissured carbonate aquifers

    SciTech Connect

    Maloszewski, P. ); Zuber, A. )

    1991-08-01

    The parallel fissure model coupled with the equation of diffusion into the matrix and with exchange reaction equations has been used to derive a simple formula for estimating the influence of matrix porosity and reaction parameters on the determination of radiocarbon ages in fissured carbonate rocks. Examples of evidently too great radiocarbon ages in carbonate formations, which are not explainable by models for the initial {sup 14}C corrections, can easily be explained by this formula. Parameters obtained for a chalk formation from a known multitracer experiment combined with a pumping test suggest a possibility of {sup 14}C ages more than three orders of magnitude greater than the ages which would be observed if the radiocarbon transport took place only in the mobile water in the fissures. It is shown that contrary to the solute movement on a small scale and with a variable input, the large-scale movement, characteristic for the {sup 14}C dating, does not necessarily require the knowledge of kinetic parameters, because they may be replaced by the distribution coefficient. Discordant tritium and {sup 14}C concentrations are commonly interpreted as a proof of mixing either in the aquifer or at the discharge site. For fissured carbonate formations, however, an alternative explanation is given by the derived model showing a considerable delay of {sup 14}C with respect to nonsorbable tracers.

  12. Tensions and Fissures: The Politics of Standardised Testing and Accountability in Ontario, 1995-2015

    ERIC Educational Resources Information Center

    Pinto, Laura Elizabeth

    2016-01-01

    While Ontario has received international accolades for its enactment of province-wide standardised testing upon the formation of the Education Quality and Accountability Office (EQAO), a closer look at provincial assessments over a 20-year span reveals successes as well as systemic tensions and fissures. The purpose of this paper is twofold.…

  13. Anatomy of the Inferior Orbital Fissure: Implications for Endoscopic Cranial Base Surgery

    PubMed Central

    De Battista, Juan Carlos; Zimmer, Lee A.; Theodosopoulos, Philip V.; Froelich, Sebastien C.; Keller, Jeffrey T.

    2012-01-01

    Considering many approaches to the skull base confront the inferior orbital fissure (IOF) or sphenomaxillary fissure, the authors examine this anatomy as an important endoscopic surgical landmark. In morphometric analyses of 50 adult human dry skulls from both sexes, we divided the length of the IOF into three segments (anterolateral, middle, posteromedial). Hemotoxylin- and eosin-stained sections were analyzed. Dissections were performed using transnasal endoscopy in four formalin-fixed cadaveric cranial specimens (eight sides); three endoscopic approaches to the IOF were performed. IOF length ranged from 25 to 35 mm (mean 29 mm). Length/width of the individual anterolateral, middle, and posteromedial segments averaged 6.46/5, 4.95/3.2, and 17.6/ 2.4 mm, respectively. Smooth muscle within the IOF had a consistent relationship with several important anatomical landmarks. The maxillary antrostomy, total ethmoidectomy approach allowed access to the posteromedial segment of the fissure. The endoscopic modified, medial maxillectomy approach allowed access to the middle and posterior-medial segment. The Caldwell-Luc approach allowed complete exposure of the IOF. The IOF serves as an important anatomic landmark during endonasal endoscopic approaches to the skull base and orbit. Each of the three segments provides a characteristic endoscopic corridor, unique to the orbit and different fossas surrounding the fissure. PMID:23542710

  14. Study of Operated Patients of Lateral Internal Anal Sphincterotomy for Chronic Anal Fissure

    PubMed Central

    Patel, Harshad Shankarlal; Chavda, Jagdish; Parikh, Jayesh; Naik, Nehal

    2013-01-01

    Introduction: Anal fissure causes significant morbidity in the population. It is proposed that elevated sphincter pressures may cause ischaemia of the anal lining and this may be responsible for the pain of anal fissures and their failure to heal. When pharmacologic therapy fails or fissures recur frequently, lateral internal sphincterotomy is the surgical treatment of choice. Material and Methods: Retrospective analysis was done of admitted and operated patients of anal fissure by lateral anal internal sphincterotomy either by open or closed technique between April 2010 and November 2011 in Gujarat Medical Education & Research Society Medical College, Sola, Ahmedabad, India. The follow-up data of all patients was evaluated for pain relief, recurrence, wound infection, incontinence to flatus or stool or both for a period of up to 6 months. Results: Wound infection rate was 10.3% in open method and 4.2% in closed method. Incontinence to flatus was 8.3% in closed method and 3.4% in open method. This was temporary and controlled within a 1 week. Incontinence to stool was 3.4% in open method which was temporary and controlled within 2 weeks while none in closed method. None of the patients in either group had come with recurrence within 6 months follow-up. Conclusion: Lateral anal internal sphincterotomy is safe regarding long term incontinence and effective regarding recurrence. PMID:24551659

  15. Response of rock-fissure seepage to snowmelt in Mount Taihang slope-catchment, North China.

    PubMed

    Cao, Jiansheng; Liu, Changming; Zhang, Wanjun

    2013-01-01

    The complex physiographic and hydrogeological systems of mountain terrains facilitate intense rock-fissure seepages and multi-functional ecological interactions. As mountain eco-hydrological terrains are the common water sources of river basins across the globe, it is critical to build sufficient understanding into the hydrological processes in this unique ecosystem. This study analyzes infiltration and soil/rock-fissure seepage processes from a 65 mm snowfall/melt in November 2009 in the typical granitic gneiss slope catchment in the Taihang Mountains. The snowfall, snowmelt and melt-water processes are monitored using soil-water time-domain reflectometry (TDR) probes and tipping bucket flowmeters. The results suggest that snowmelt infiltration significantly influences soil/rock water seepage in the 0-100 cm soil depth of the slope-catchment. It is not only air temperature that influences snowmelt, but also snowmelt infiltration and rock-fissure seepage. Diurnal variations in rock-fissure seepage are in close correlation with air temperature (R(2) > 0.7). Temperature also varies with soil/rock water viscosity, which element in turn influences soil/rock water flow. Invariably, water dynamics in the study area is not only a critical water supply element for domestic, industrial and agricultural uses, but also for food security and social stability. PMID:23128629

  16. Identification of genetic loci underlying the kernel fissure-resistance exhibited by 'cypress' and 'saber'

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The economic value of broken rice is about half that of whole milled rice, so one goal of producers, millers, and rice breeders is to reduce broken grains that result from the dehusking and milling processes One of the primary causes of rice breakage is fissuring, or cracking, of the rice before it ...

  17. Rice fissure resistance QTLs from ‘Saber’ complement those from ‘Cypress’

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The economic value of broken rice is about half that of whole milled rice, so one goal of producers, millers, and rice breeders is to reduce grain breakage during the dehusking and milling processes. One of the primary causes of rice breakage is fissuring, or cracking, of the rice before it enters ...

  18. Effect of an Antibacterial Monomer on the Antibacterial Activity of a Pit-and-Fissure Sealant

    PubMed Central

    Dong, Yan; Zhang, Ling; Sun, Xiang; Liu, Zhengya; Guo, Huihui; Huang, Li; Chen, Jihua

    2016-01-01

    Resin-based pit-and-fissure sealants are often used to form a barrier on the occlusal surface of molars to treat caries lesions; however, bacteria can remain in the pit and fissures without detection, increasing the risk of secondary caries. Sealants with antimicrobial properties or microbial repellent actions might be advantageous. The aim of this study was to assess the inhibitory effect of a 2-methacryloxylethyl dodecyl methyl ammonium bromide (MAE-DB)-incorporated sealant against Streptococcus mutans. MAE-DB (4% wt) was incorporated into a commercially available sealant, Eco-S resin-based pit-and-fissure sealant (Vericom Co., Ltd., Korea); a sealant without MAE-DB served as a negative control, and Clinpro™ Sealant (3M™ ESPE™), a fluoride-releasing resin, was used as a commercial control. The effects of the cured sealants and their eluents on the growth of S. mutans were determined according to colony-forming unit counts and metabolic tests. The effects of the cured sealants on the adherence and membrane integrity of S. mutans were investigated using confocal laser-scanning microscopy (CLSM) in conjunction with fluorescent indicators. Compared with the negative control and commercial control, the cured MAE-DB-incorporated pit-and-fissure sealant exhibited a significant inhibitory effect on the growth of S. mutans (P < 0.05), whereas the eluents did not show any detectable antibacterial activity. The commercial control also showed no detectable bactericidal activity. Moreover, the aged experimental material retained its property of contact inhibition of biofilm formation. The fluorescence analysis of CLSM images demonstrated that the cured MAE-DB-incorporated sealant could hamper the adherence of S. mutans and exert a detrimental effect on bacterial membrane integrity. The incorporation of MAE-DB can render a pit-and-fissure sealant with contact antibacterial activity after polymerization via influencing the growth, adherence, and membrane integrity of S

  19. Ecology of deep-sea hydrothermal vent communities: A review

    SciTech Connect

    Lutz, R.A.; Kennish, M.J. )

    1993-08-01

    The present article reviews studies of the past 15 years of active and inactive hydrothermal vents. The focus of the discussion is on the ecology of the biological communities inhabiting hydrothermal vents. These communities exhibit high densities and biomass, low species diversity, rapid growth rates, and high metabolic rates. The authors attempt to relate the biology of hydrothermal vent systems to geology. Future directions for hydrothermal vent research are suggested. Since many vent populations are dependent on hydrothermal fluids and are consequently unstable, both short- and long-term aspects of the ecology of the vent organisms and the influence of chemical and geological factors on the biology of vent systems need to be established. 200 refs., 28 figs.

  20. Effect of Local Crystallographic Texture on the Fissure Formation During Charpy Impact Testing of Low-Carbon Steel

    NASA Astrophysics Data System (ADS)

    Ghosh, Abhijit; Patra, Sudipta; Chatterjee, Arya; Chakrabarti, Debalay

    2016-06-01

    The severity of the formation of fissures (also known as splitting or delamination) on the fracture surface of Charpy impact-tested samples of a low-carbon steel has been found to increase with the decrease in finish rolling temperature [1093 K to 923 K (820 °C to 650 °C)]. Combined scanning electron microscopy and electron back-scattered diffraction study revealed that crystallographic texture was the prime factor responsible for the fissure formation. Through-thickness texture band composed of cube [Normal Direction (ND)║<001>] and gamma [ND║<111>] orientations developed during the inter-critical rolling treatment. Strain incompatibility between these two texture bands causes fissure cracking on the main fracture plane. A new approach based on the angle between {001} planes of neighboring crystals has been employed in order to estimate the `effective grain size,' which is used to determine the cleavage fracture stress on different planes of a sample. The severity of fissure formation was found to be directly related to the difference in cleavage fracture stress between the `main fracture plane' and `fissure plane.' Clustering of ferrite grains having cube texture promoted the fissure crack propagation along the transverse `fissure plane,' by increasing the `effective grain size' and decreasing the cleavage fracture stress on that plane.

  1. The Biological Deep Sea Hydrothermal Vent as a Model to Study Carbon Dioxide Capturing Enzymes

    PubMed Central

    Minic, Zoran; Thongbam, Premila D.

    2011-01-01

    Deep sea hydrothermal vents are located along the mid-ocean ridge system, near volcanically active areas, where tectonic plates are moving away from each other. Sea water penetrates the fissures of the volcanic bed and is heated by magma. This heated sea water rises to the surface dissolving large amounts of minerals which provide a source of energy and nutrients to chemoautotrophic organisms. Although this environment is characterized by extreme conditions (high temperature, high pressure, chemical toxicity, acidic pH and absence of photosynthesis) a diversity of microorganisms and many animal species are specially adapted to this hostile environment. These organisms have developed a very efficient metabolism for the assimilation of inorganic CO2 from the external environment. In order to develop technology for the capture of carbon dioxide to reduce greenhouse gases in the atmosphere, enzymes involved in CO2 fixation and assimilation might be very useful. This review describes some current research concerning CO2 fixation and assimilation in the deep sea environment and possible biotechnological application of enzymes for carbon dioxide capture. PMID:21673885

  2. The biological deep sea hydrothermal vent as a model to study carbon dioxide capturing enzymes.

    PubMed

    Minic, Zoran; Thongbam, Premila D

    2011-01-01

    Deep sea hydrothermal vents are located along the mid-ocean ridge system, near volcanically active areas, where tectonic plates are moving away from each other. Sea water penetrates the fissures of the volcanic bed and is heated by magma. This heated sea water rises to the surface dissolving large amounts of minerals which provide a source of energy and nutrients to chemoautotrophic organisms. Although this environment is characterized by extreme conditions (high temperature, high pressure, chemical toxicity, acidic pH and absence of photosynthesis) a diversity of microorganisms and many animal species are specially adapted to this hostile environment. These organisms have developed a very efficient metabolism for the assimilation of inorganic CO₂ from the external environment. In order to develop technology for the capture of carbon dioxide to reduce greenhouse gases in the atmosphere, enzymes involved in CO₂ fixation and assimilation might be very useful. This review describes some current research concerning CO₂ fixation and assimilation in the deep sea environment and possible biotechnological application of enzymes for carbon dioxide capture.

  3. The biological deep sea hydrothermal vent as a model to study carbon dioxide capturing enzymes.

    PubMed

    Minic, Zoran; Thongbam, Premila D

    2011-01-01

    Deep sea hydrothermal vents are located along the mid-ocean ridge system, near volcanically active areas, where tectonic plates are moving away from each other. Sea water penetrates the fissures of the volcanic bed and is heated by magma. This heated sea water rises to the surface dissolving large amounts of minerals which provide a source of energy and nutrients to chemoautotrophic organisms. Although this environment is characterized by extreme conditions (high temperature, high pressure, chemical toxicity, acidic pH and absence of photosynthesis) a diversity of microorganisms and many animal species are specially adapted to this hostile environment. These organisms have developed a very efficient metabolism for the assimilation of inorganic CO₂ from the external environment. In order to develop technology for the capture of carbon dioxide to reduce greenhouse gases in the atmosphere, enzymes involved in CO₂ fixation and assimilation might be very useful. This review describes some current research concerning CO₂ fixation and assimilation in the deep sea environment and possible biotechnological application of enzymes for carbon dioxide capture. PMID:21673885

  4. The effects of vent-notch area on bulging and thinning during the clad vent test closure-weld operation

    SciTech Connect

    Ulrich, G.B.

    1996-09-01

    The internal gas pressure during clad vent set (CVS) welding is vented through aligned vent notches in each cup. For Galileo, Ulysses, and most of Cassini CVS production, the vent-notch dimensional requirements for both cups were as follows: (1) vent-notch depth, 0.15/0.20 mm; (2) vent-notch width, 0.25/0.35 nun; (3) bottom of vent-notch comers, sharp to full radius; (4) top of vent-notch edge, 0.05 mm maximum break; and (5) maximum variation between vent notch and grit-blasted triangle centerlines, 3{degrees}. During the fuel encapsulation operation (with {sup 238}PuO{sub 2} fuel pellets) at Los Alamos National Laboratory (LANL), excessive bulges or blowouts at the CVS closure-weld tie-in location occurred with 11.8% (27 out of 229) of the flight-quality welds made with the aforementioned standard vent-notch dimensions. These bulges and blowouts are primarily the result of inadequate venting of the increased gas pressure during the thermal cycle of the closure-weld operation. Proper venting is dependent mostly upon the weld parameters and the total vent-notch area. Because of the increased incidence of bulges/blowouts in the {sup 238}PuO{sub 2}-fueled CVS units, LANL personnel requested that consideration be given to increasing the vent-notch size to minimize further the loss of CVS hardware and the potential loss of {sup 238}PuO{sub 2} pellets. Thus, increasing further the production yield of the closure-weld operation would avoid potentially severe schedule delays.

  5. Comparative Study of Vented vs. Unvented Crawlspaces

    SciTech Connect

    Biswas, Kaushik; Christian, Jeffrey E; Gehl, Anthony C

    2011-10-01

    There has been a significant amount of research in the area of building energy efficiency and durability. However, well-documented quantitative information on the impact of crawlspaces on the performance of residential structures is lacking. The objective of this study was to evaluate and compare the effects of two crawlspace strategies on the whole-house performance of a pair of houses in a mixed humid climate. These houses were built with advanced envelope systems to provide energy savings of 50% or more compared to traditional 2010 new construction. One crawlspace contains insulated walls and is sealed and semi-conditioned. The other is a traditional vented crawlspace with insulation in the crawlspace ceiling. The vented (traditional) crawlspace contains fiberglass batts installed in the floor chase cavities above the crawl, while the sealed and insulated crawlspace contains foil-faced polyisocyanurate foam insulation on the interior side of the masonry walls. Various sensors to measure temperatures, heat flux through crawlspace walls and ceiling, and relative humidity were installed in the two crawlspaces. Data from these sensors have been analyzed to compare the performance of the two crawlspace designs. The analysis results indicated that the sealed and insulated crawlspace design is better than the traditional vented crawlspace in the mixed humid climate.

  6. King's Bowl Pit Crater, Lava Field and Eruptive Fissure, Idaho - A Multipurpose Volcanic Planetary Analog

    NASA Astrophysics Data System (ADS)

    Hughes, S. S.; Garry, B.; Kobs-Nawotniak, S. E.; Sears, D. W. G.; Borg, C.; Elphic, R. C.; Haberle, C. W.; Kobayashi, L.; Lim, D. S. S.; Sears, H.; Skok, J. R.; Heldmann, J. L.

    2014-12-01

    King's Bowl (KB) and its associated eruptive fissure and lava field on the eastern Snake River Plain, is being investigated by the NASA SSERVI FINESSE (Field Investigations to Enable Solar System Science and Exploration) team as a planetary analog to similar pits on the Moon, Mars and Vesta. The 2,220 ± 100 BP basaltic eruption in Craters of the Moon National Monument and Preserve represents early stages of low shield growth, which was aborted when magma supply was cut off. Compared to mature shields, KB is miniscule, with ~0.02 km3 of lava over ~3 km2, yet the ~6 km long series of fissures, cracks and pits are well-preserved for analog studies of volcanic processes. The termination of eruption was likely related to proximity of the 2,270 ± 50 BP eruption of the much larger Wapi lava field (~5.5 km3 over 325 km2 area) on the same rift. Our investigation extends early work by R. Greeley and colleagues, focusing on imagery, compositional variations, ejecta distribution, dGPS profiles and LiDAR scans of features related to: (1) fissure eruptions - spatter ramparts, cones, feeder dikes, extension cracks; (2) lava lake formation - surface morphology, squeeze-ups, slab pahoehoe lava mounds, lava drain-back, flow lobe overlaps; and (3) phreatic steam blasts - explosion pits, ejecta blankets of ash and blocks. Preliminary results indicate multiple fissure eruptions and growth of a basin-filled lava lake up to ~ 10 m thick with outflow sheet lava flows. Remnant mounds of original lake crust reveal an early high lava lake level, which subsided as much as 5 m as the molten interior drained back into the fissure system. Rapid loss of magma supply led to the collapse of fissure walls allowing groundwater influx that triggered multiple steam blasts along at least 500 m. Early blasts occurred while lake magma pressure was still high enough to produce squeeze-ups when penetrated by ejecta blocks. The King's Bowl pit crater exemplifies processes of a small, but highly energetic

  7. Ecology of deep-sea hydrothermal vent communities: A review

    NASA Astrophysics Data System (ADS)

    Lutz, Richard A.; Kennish, Michael J.

    1993-08-01

    Studies of the many active and inactive hydrothermal vents found during the past 15 years have radically altered views of biological and geological processes in the deep sea. The biological communities occupying the vast and relatively stable soft bottom habitats of the deep sea are characterized by low population densities, high species diversity, and low biomass. In contrast, those inhabiting the generally unstable conditions of hydrothermal vent environments exhibit high densities and biomass, low species diversity, rapid growth rates, and high metabolic rates. Biological processes, such as rates of metabolism and growth, in vent organisms are comparable to those observed in organisms from shallow-water ecosystems. An abundant energy source is provided by chemosynthetic bacteria that constitute the primary producers sustaining the lush communities at the hydrothermal sites. Fluxes in vent flow and fluid chemistry cause changes in growth rates, reproduction, mortality, and/or colonization of vent fauna, leading to temporal and spatial variation of the vent communities. Vent populations that cannot adapt to modified flow rates are adversely affected, as is evidenced by high mortality or lower rates of colonization, growth, or reproduction. Substantial changes in biota have been witnessed at several vents, and successional cycles have been proposed for the Galapagos vent fields. Dramatic temporal and spatial variations in vent community structure may also relate to variations in larval dispersal and chance recruitment, as well as biotic interactions.

  8. A case of focal lung infarction following right upper lobectomy in case of undeveloped lung fissure.

    PubMed

    Parissis, Haralabos; Booth, Karen; Al-Alao, Bassel

    2015-09-01

    We present a case of infarction of residual upper lobe tissue during right upper lobectomy. We believe that although the blood supply to the upper lobe had been isolated and divided in order to perform the right upper lobectomy, residual right upper lobe had been left behind secondary to "poorly estimated" staple separation of the upper from the middle lobe in a patient with non-developed oblique fissure. We suggest that in this situation the upper lobe bronchus should be identified and clamped and the lung re-inflated in order to accurately demarcate the borders of the upper and middle lobe prior to the application of the stapler to prevent infarction of residual upper lobe tissue. Therefore, this case emphasises that routine lung inflation during fissure development in right upper lobectomy may prevent unpredictable complications.

  9. Painful ophthalmoplegia secondary to a mucocele involving the sella turcica, superior orbital fissure, and sphenoid sinus.

    PubMed

    Clarke, H; Clarke, V; Gill, J; St John, A; Lashley, M

    1992-03-01

    A case of painful ophthalmoplegia associated with an extensive lesion involving the sella turcica, superior orbital fissure, and sphenoid sinus in a 57-year-old man is reported. Even though nasal and ocular symptoms and signs represent the usual features of sphenoidal mucoceles, extension to the intracranial cavity as seen in this lesion is rare. Surgical exploration via a sublabial, transseptal approach revealed a mucocele of the sphenoid sinus. This case exhibited extensive and aggressive behavior simulating a malignant neoplasm.

  10. Artificial recharge through a well in fissured carbonate rock, west St. Paul, Minnesota

    USGS Publications Warehouse

    Reeder, Harold O.; Wood, Warren W.; Ehrlich, G.G.; Sun, Ren Jen

    1976-01-01

    The injection test demonstrated that it is hydrologically feasible to recharge the Prairie du Chien Group and the Jordan Sandstone artificially through wells completed in the Prairie du Chien Group. The fissures in the Prairie du Chien Group act as conduits through which water spreads. The water passes into the Jordan Sandstone from the Prairie du Chien over a larger area than it would if it were injected directly into the Jordan.

  11. Comparative Evaluation of the Marginal Sealing Ability of two Commercially Available Pit and Fissure Sealants

    PubMed Central

    Moses, Joyson; Rangeeth, Bollam Nammalwar; Sivakumar, Subramanian

    2016-01-01

    Introduction The occlusal surfaces of the teeth usually have pits and fissures which provide a good environment for demineralization with minimal salivary access and make them caries prone. The success of pit and fissure sealing materials is highly dependent on the marginal sealing ability of the fissures. Aim The present study was carried out to evaluate and compare the marginal sealing ability of two commercially available pit and fissure sealants. Materials and Methods A total of 50 human premolar teeth were used in this invitro study. Group 1 included 25 teeth for application of Clinpro sealant and Group 2 included twenty 25 for application of Helioseal F sealant. Samples were stored in artificial saliva for 72 hours before thermocycling. The samples were immersed in 2% methylene blue solution for 24 hours. The sectioned samples were examined under an Optical Stereomicroscope and compared in terms of the extent of microleakage based on the amount of dye penetration between the sealant and tooth substance interface. The dye penetration scores in both the groups was statistically analysed using Chi square test and Mann Whitney Test. A p-value of less than 0.05 was considered to be statistically significant. Results It was seen that in Group 1, 12 samples (48%) had no dye penetration (Grade 0) while in Group 2, 6 samples (24%) demonstrated Grade 0 penetration. Group 2 had the most extensive dye penetration (Grade 3) in 8 of 25 samples (32%) (p=0.014). Conclusion On comparison of the microleakage scores of the groups, a statistically significant difference was found between the two groups; indicating a much better performance of Clinpro as compared to Helioseal F. PMID:27790568

  12. [Surgical therapy of chronic anal fissure--do additional proctologic operations impair continence?].

    PubMed

    Pfeifer, J; Berger, A; Uranüs, S

    1994-07-01

    78 patients with chronic anal fissures have been mainly operated on by lateral internal sphincterotomy (LATS). Continence have been evaluated by questionnaire at least 9 months postoperatively. Patient without any additional proctological operation had minor disturbances of continence in 17%. Patient with additional operations had disturbances of continence in 30%. Especially the subgroup of patients with LATS and haemorrhoidectomy had bad results. In this group only 45% were fully continent.

  13. Sizing an emergency venting system for a cryogenic dewar

    NASA Technical Reports Server (NTRS)

    Liu, C. K.; Naes, L. G.; Manikowski, A. F., Jr.

    1986-01-01

    If the vacuum vessel that insulates a cryogenic dewar for a spaceborne experiment prior to launch is damaged, air will leak into the vacuum insulation space. As the sudden heat load causes the pressure to rise in the dewar, a safety disk in the emergency vent line will burst at the design pressure differential to allow vaporized cryogenic fluid to escape. The emergency vent line should be sized such that sufficient gaseous cryogen will be vented to keep the pressure inside the dewar below the design limit. On the other hand, the line should not be so large as to impose an unnecessary heat load on the dewar filled with cryogenic fluid. A vent-line computer program was generated to compute the maximum flow rate allowed for a proposed vent-line system. Parametric studies have been carried out for different burst disk pressure differentials, liquid cryogen ullage, and vent-line sizes.

  14. Potential for aquifer compaction, land subsidence, and earth fissures in the Tucson basin, Pima County, Arizona

    USGS Publications Warehouse

    Anderson, S.R.

    1987-01-01

    In 1979 the U.S. Geological Survey, in cooperation with the city of Tucson, began an investigation of aquifer compaction and its effects in the Tucson basin, including the potential hazards of aquifer compaction and subsequent damage to engineered structures, roads, water supply systems, gaslines, and sewage systems. Groundwater is the main source of water for irrigation, public supply, and industry. Pumping has exceeded recharge for several decades, and declines in groundwater levels have occurred in parts of the basin. In places, water level declines have resulted in small amounts of aquifer compaction and land subsidence. Further water level declines in parts of the Tucson basin may result in large amounts of aquifer compaction and land subsidence. Differential land subsidence may, in places, be accompanied by the formation of earth fissures. Aquifer compaction, land subsidence, and earth fissures can damage or affect the functional capability of manmade features. Specifically, aquifer compaction may damage wells, fissures may damage engineered structures, and differential land subsidence may affect structures such as sewers and water-supply systems that are dependent on gravity for their operation. (USGS)

  15. Squamotympanic fissure in the Ngandong and Sambungmacan hominids: a reply to Delson et al.

    PubMed

    Durband, Arthur C

    2002-03-01

    In the present study the course of the squamotympanic fissure of the mandibular fossa is examined in several fossil hominid specimens. While previous work by several authors had found that the course of this fissure was potentially autapomorphic for the Ngandong and Sambungmacan fossil samples from Indonesia, a more recent study performed by Delson et al. (Anat Rec 2001; 262:380--397) reported that a number of other fossils, including OH 9, Sangiran 4 and 17, and KNM WT 15000 were similar to the Ngandong and Sambungmacan specimens in the expression of this feature. To test these findings, those specimens purported to share similarities with Ngandong and Sambungmacan were examined. The results of this study indicate clearly differing morphologies between the Ngandong and Sambungmacan fossils, on the one hand, and the four African and Indonesian fossils named by Delson et al. (2001). Hence, the course of the squamotympanic fissure remains a potentially autapomorphic feature separating the Ngandong and Sambungmacan samples from the remaining specimens allocated to Homo erectus.

  16. Endoscopic endonasal anatomy of superior orbital fissure and orbital apex regions: critical considerations for clinical applications.

    PubMed

    Dallan, Iacopo; Castelnuovo, Paolo; de Notaris, Matteo; Sellari-Franceschini, Stefano; Lenzi, Riccardo; Turri-Zanoni, Mario; Battaglia, Paolo; Prats-Galino, Alberto

    2013-05-01

    The superior orbital fissure is a critical three-dimensional space connecting the middle cranial fossa and the orbit. From an endoscopic viewpoint, only the medial aspect has a clinical significance. It presents a critical relationship with the lateral sellar compartment, the pterygopalatine fossa and the middle cranial fossa. The connective tissue layers and neural and vascular structures of this region are described. The role of Muller's muscle is confirmed, and the utility of the maxillary and optic strut is outlined. Muller's muscle extends for the whole length of the inferior orbital fissure, passes over the maxillary strut and enters the superior orbital fissure, representing a critical surgical landmark. Dividing the tendon between the medial and inferior rectus muscle allows the identification of the main trunk of the oculomotor nerve, and a little laterally, it is usually possible to visualize the first part of the ophthalmic artery. Based on a better knowledge of anatomy, we trust that this area could be readily addressed in clinical situations requiring an extended approach in proximity of the orbital apex.

  17. Flashback flame arrester devices for fuel cargo tank vapor vents

    NASA Technical Reports Server (NTRS)

    Bjorklund, R. A.; Kushida, R. O.

    1981-01-01

    The flame quenching capability of four types of flame arresting devices suitable for installation on fuel cargo tank vents of marine transport vessels is evaluated. A single 30 mesh screen, a dual 20 mesh screen, a spiral wound crimped metal ribbon, and a packed bed of ballast rings were tested. Flame speed and flame penetration of the test arresters were determined. Eight fuels representative of bulk cargoes were tested. The test arresters quenched a minimum of three flashback flames from all eight fuels, with one exception: high speed ethylene flames penetrated the dual 20 mesh screen on three tests. The arresters withstood the sustained flame from a propane/air mixture for 30 minutes. None of the arresters withstood the sustained flame from an ethylene/air mixture for more than 7 minutes.

  18. Experimental investigation of external explosion in the venting process*

    PubMed Central

    Du, Zhi-min; Jin, Xin-qiao; Cui, Dong-ming; Ye, Jing-fang

    2005-01-01

    Experimental investigations were conducted on the process of combustion and explosion vent in a 200 mm (diameter)×400 mm (length) vertical cylindrical vessel. When CH4-air mixture gases were used and the vent diameter was 55 mm, conditions of Φ (equivalent ratio)=0.8, Φ=1.0 and Φ=1.3 and two ignition positions (at the cylinder center and bottom) were selected. The venting processes and the correlated factors are discussed in this paper. PMID:15822147

  19. 46 CFR 153.353 - High velocity vents.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false High velocity vents. 153.353 Section 153.353 Shipping... Systems § 153.353 High velocity vents. The discharge point of a B/3 or 4m venting system must be located..., unimpeded jet; (b) The jet has a minimum exit velocity of 30 m/sec (approx. 98.4 ft/sec); and (c) The...

  20. 46 CFR 153.353 - High velocity vents.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false High velocity vents. 153.353 Section 153.353 Shipping... Systems § 153.353 High velocity vents. The discharge point of a B/3 or 4m venting system must be located..., unimpeded jet; (b) The jet has a minimum exit velocity of 30 m/sec (approx. 98.4 ft/sec); and (c) The...

  1. 46 CFR 153.353 - High velocity vents.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false High velocity vents. 153.353 Section 153.353 Shipping... Systems § 153.353 High velocity vents. The discharge point of a B/3 or 4m venting system must be located..., unimpeded jet; (b) The jet has a minimum exit velocity of 30 m/sec (approx. 98.4 ft/sec); and (c) The...

  2. 46 CFR 153.353 - High velocity vents.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false High velocity vents. 153.353 Section 153.353 Shipping... Systems § 153.353 High velocity vents. The discharge point of a B/3 or 4m venting system must be located..., unimpeded jet; (b) The jet has a minimum exit velocity of 30 m/sec (approx. 98.4 ft/sec); and (c) The...

  3. 46 CFR 153.353 - High velocity vents.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false High velocity vents. 153.353 Section 153.353 Shipping... Systems § 153.353 High velocity vents. The discharge point of a B/3 or 4m venting system must be located..., unimpeded jet; (b) The jet has a minimum exit velocity of 30 m/sec (approx. 98.4 ft/sec); and (c) The...

  4. An Experimental and Numerical Study on Cracking Behavior of Brittle Sandstone Containing Two Non-coplanar Fissures Under Uniaxial Compression

    NASA Astrophysics Data System (ADS)

    Yang, Sheng-Qi; Tian, Wen-Ling; Huang, Yan-Hua; Ranjith, P. G.; Ju, Yang

    2016-04-01

    To understand the fracture mechanism in all kinds of rock engineering, it is important to investigate the fracture evolution behavior of pre-fissured rock. In this research, we conducted uniaxial compression experiments to evaluate the influence of ligament angle on the strength, deformability, and fracture coalescence behavior of rectangular prismatic specimens (80 × 160 × 30 mm) of brittle sandstone containing two non-coplanar fissures. The experimental results show that the peak strength of sandstone containing two non-coplanar fissures depends on the ligament angle, but the elastic modulus is not closely related to the ligament angle. With the increase of ligament angle, the peak strength decreased at a ligament angle of 60°, before increasing up to our maximum ligament angle of 120°. Crack initiation, propagation, and coalescence were all observed and characterized from the inner and outer tips of pre-existing non-coplanar fissures using photographic monitoring. Based on the results, the sequence of crack evolution in sandstone containing two non-coplanar fissures was analyzed in detail. In order to fully understand the crack evolution mechanism of brittle sandstone, numerical simulations using PFC2D were performed for specimens containing two non-coplanar fissures under uniaxial compression. The results are in good agreement with the experimental results. By analyzing the stress field, the crack evolution mechanism in brittle sandstone containing two non-coplanar fissures under uniaxial compression is revealed. These experimental and numerical results are expected to improve the understanding of the unstable fracture mechanism of fissured rock engineering structures.

  5. Scientists as stakeholders in conservation of hydrothermal vents.

    PubMed

    Godet, Laurent; Zelnio, Kevin A; VAN Dover, Cindy L

    2011-04-01

    Hydrothermal vents are deep-sea ecosystems that are almost exclusively known and explored by scientists rather than the general public. Continuing scientific discoveries arising from study of hydrothermal vents are concommitant with the increased number of scientific cruises visiting and sampling vent ecosystems. Through a bibliometric analysis, we assessed the scientific value of hydrothermal vents relative to two of the most well-studied marine ecosystems, coral reefs and seagrass beds. Scientific literature on hydrothermal vents is abundant, of high impact, international, and interdisciplinary and is comparable in these regards with literature on coral reefs and seagrass beds. Scientists may affect hydrothermal vents because their activities are intense and spatially and temporally concentrated in these small systems. The potential for undesirable effects from scientific enterprise motivated the creation of a code of conduct for environmentally and scientifically benign use of hydrothermal vents for research. We surveyed scientists worldwide engaged in deep-sea research and found that scientists were aware of the code of conduct and thought it was relevant to conservation, but they did not feel informed or confident about the respect other researchers have for the code. Although this code may serve as a reminder of scientists' environmental responsibilities, conservation of particular vents (e.g., closures to human activity, specific human management) may effectively ensure sustainable use of vent ecosystems for all stakeholders.

  6. Fissure sealant retention: a comparison of three sealant types under field conditions.

    PubMed

    Barrie, A M; Stephen, K W; Kay, E J

    1990-09-01

    Two two-year double-blind clinical trials were undertaken involving the newly-erupted first permanent molars of 133 children aged 5-6 years at the outset. In one study of 76 subjects, half the teeth were sealed with the filled sealants Prismashield or Estiseal. In the other study of 58 children, half were again sealed with Prismashield, and the others with the unfilled Concise white sealant, by a community dental service hygienist, as part of her routine dental duties. Subjects were examined under blind conditions at 6 monthly intervals and, by 24 months in the first study, 71 per cent of Prismashield sites were intact and caries-free, compared with only 53 per cent of Estiseal-treated tooth units (P less than 0.001). In the second study comparing Prismashield and Concise, by two years, 81 per cent of Prismashield resins were complete, compared with 88 per cent of the nonfilled Concise material. There were, however, no differences noted with respect to buccal and palatal site retention for either study. It can be concluded that Estiseal is a poorer material than Prismashield, certainly in relation to its bulk retention properties. Nonetheless it is possible that, along with other tooth-coloured/transparent resins, small fragments may not be as readily detectable as is the case with the unfilled Concise white sealant. However, as the abrasion resistance of unfilled materials is poorer than that of filled resins, the similar buccal/palatal site retention for Prismashield and Concise was also unexpected. Nevertheless this study illustrates again the value of sealant placement in the erupting first permanent molars of 5-6-year-old children, at a time when these teeth are most susceptible to carious attack.

  7. 14 CFR 23.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... from the top part of the expansion space. In addition— (1) Each vent outlet must be located and... or level flight attitudes, unless drainage is provided. Any drain valve installed must be accessible... be arranged to prevent the loss of fuel, except fuel discharged because of thermal expansion,...

  8. 14 CFR 23.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... from the top part of the expansion space. In addition— (1) Each vent outlet must be located and... or level flight attitudes, unless drainage is provided. Any drain valve installed must be accessible... be arranged to prevent the loss of fuel, except fuel discharged because of thermal expansion,...

  9. Wisely use emergency scrubbers with vent systems

    SciTech Connect

    Bravo, F.; Cooper, R.S.; Contreras, D.

    1997-08-01

    Addressing the control of the gas stream constituents from emergency vents and their final disposal is an important consideration for chemical process industries (CPI) plant design and operation. Emergency scrubbing is a practical means of dealing with toxic, dangerous, or corrosive chemical products. The number of scrubber references is considerable and covers particulate and gaseous emissions. Applying scrubbers to mitigate the release of hazardous substances during emergency circumstances has been less well documented. This article reviews both the design and the operational considerations of scrubbers in emergency service.

  10. Geomicrobiology of Deep-Sea Hydrothermal Vents

    NASA Astrophysics Data System (ADS)

    Jannasch, Holger W.; Mottl, Michael J.

    1985-08-01

    During the cycling of seawater through the earth's crust along the midocean ridge system, geothermal energy is transferred into chemical energy in the form of reduced inorganic compounds. These compounds are derived from the reaction of seawater with crustal rocks at high temperatures and are emitted from warm (<= 25 degrees C) and hot (~ 350 degrees C) submarine vents at depths of 2000 to 3000 meters. Chemolithotrophic bacteria use these reduced chemical species as sources of energy for the reduction of carbon dioxide (assimilation) to organic carbon. These bacteria form the base of the food chain, which permits copious populations of certain specifically adapted invertebrates to grow in the immediate vicinity of the vents. Such highly prolific, although narrowly localized, deep-sea communities are thus maintained primarily by terrestrial rather than by solar energy. Reduced sulfur compounds appear to represent the major electron donors for aerobic microbial metabolism, but methane-, hydrogen-, iron-, and manganese-oxidizing bacteria have also been found. Methanogenic, sulfur-respiring, and extremely thermophilic isolates carry out anaerobic chemosynthesis. Bacteria grow most abundantly in the shallow crust where upwelling hot, reducing hydrothermal fluid mixes with downwelling cold, oxygenated seawater. The predominant production of biomass, however, is the result of symbiotic associations between chemolithotrophic bacteria and certain invertebrates, which have also been found as fossils in Cretaceous sulfide ores of ophiolite deposits.

  11. Diffuse flow from hydrothermal vents. Doctoral thesis

    SciTech Connect

    Trivett, D.A.

    1991-08-01

    The effluent from a collection of diffuse hydrothermal vents was modelled to determine the fate of the source of flow under typical environmental conditions at seafloor spreading centers. A laboratory simulation was conducted to test an analytic model of diffuse plume rise. The results showed that diffuse plumes are likely to remain near the seafloor, with their maximum rise height scaled with the diameter of the source of diffuse flow. The entrainment of ambient seawater into these plumes is limited by the proximity to the seafloor, thus slowing the rate of dilution. The model of diffuse plume behaviour was used to guide the design and implementation of a scheme for monitoring the flow from diffuse hydrothermal vents in the ocean. A deployment of an array at the Southern Juan de Fuca Ridge yielded measurements of a variety of diffuse plume properties, including total heat output. Two distinct sources of hydrothermal flow were detected during the field deployment. The larger source was 1-1.5km north of the instrument array, and its energy output was 450 + or - 270MW. A smaller source was located 100m east of one instrument in the array. The energy output of the source was 12 + or - 8MW. The rise heights of the centerlines of these plumes were 45m and 10m, respectively.

  12. Geomicrobiology of deep-sea hydrothermal vents.

    PubMed

    Jannasch, H W; Mottl, M J

    1985-08-23

    During the cycling of seawater through the earth's crust along the mid-ocean ridge system, geothermal energy is transferred into chemical energy in the form of reduced inorganic compounds. These compounds are derived from the reaction of seawater with crustal rocks at high temperatures and are emitted from warm (vents at depths of 2000 to 3000 meters. Chemolithotrophic bacteria use these reduced chemical species as sources of energy for the reduction of carbon dioxide (assimilation) to organic carbon. These bacteria form the base of the food chain, which permits copious populations of certain specifically adapted invertebrates to grow in the immediate vicinity of the vents. Such highly prolific, although narrowly localized, deep-sea communities are thus maintained primarily by terrestrial rather than by solar energy. Reduced sulfur compounds appear to represent the major electron donors for aerobic microbial metabolism, but methane-, hydrogen-, iron-, and manganese-oxidizing bacteria have also been found. Methanogenic, sulfur-respiring, and extremely thermophilic isolates carry out anaerobic chemosynthesis. Bacteria grow most abundantly in the shallow crust where upwelling hot, reducing hydrothermal fluid mixes with downwelling cold, oxygenated seawater. The predominant production of biomass, however, is the result of symbiotic associations between chemolithotrophic bacteria and certain invertebrates, which have also been found as fossils in Cretaceous sulfide ores of ophiolite deposits.

  13. MAVEN Contamination Venting and Outgassing Analysis

    NASA Technical Reports Server (NTRS)

    Petro, Elaine M.; Hughes, David W.; Secunda, Mark S.; Chen, Philip T.; Morrissey, James R.; Riegle, Catherine A.

    2014-01-01

    Mars Atmosphere and Volatile EvolutioN (MAVEN) is the first mission to focus its study on the Mars upper atmosphere. MAVEN will study the evolution of the Mars atmosphere and climate, by examining the conduit through which the atmosphere has to pass as it is lost to the upper atmosphere. An analysis was performed for the MAVEN mission to address two distinct concerns. The first goal of the analysis was to perform an outgassing study to determine where species outgassed from spacecraft materials would redistribute to and how much of the released material might accumulate on sensitive surfaces. The second portion of the analysis serves to predict what effect, if any, Mars atmospheric gases trapped within the spacecraft could have on instrument measurements when re-released through vents. The re-release of atmospheric gases is of interest to this mission because vented gases from a higher pressure spacecraft interior could bias instrument measurements of the Mars atmosphere depending on the flow rates and directions.

  14. Conceptual design of soil venting systems

    SciTech Connect

    DePaoli, D.W.; Wilson, J.H.; Thomas, C.O.

    1996-05-01

    A method for economically based conceptual design of soil venting systems is described. The objective of this method is to provide a means of estimating the cost and schedule of site cleanup for the purposes of technology selection and for focusing detailed system design. Idealized treatments of contaminant volatilization and flow of gas in the soil are employed to obtain estimates of transient off-gas concentration and the vacuum required at the extraction vents for a given set of site and system design conditions. Capital and operating costs of blowers and emissions control devices are estimated using standard techniques, allowing comparison of the required processing cost for cleanup under various design strategies. The utility of this technique is illustrated for an example case of a 95,000-L (25,000-gal) JP-4 jet fuel spill. The results for this test case indicate that emissions control predictably increases cleanup cost, with carbon adsorption being more costly than catalytic oxidation. This treatment predicts that an optimum flow rate and system size exist for each design strategy at a particular site.

  15. Feasibility and Safety Assessment for Advanced Reactor Concepts Using Vented Fuel

    SciTech Connect

    Klein, Andrew; Matthews, Topher; Lenhof, Renae; Deason, Wesley; Harter, Jackson

    2015-01-16

    Recent interest in fast reactor technology has led to renewed analysis of past reactor concepts such as Gas Fast Reactors and Sodium Fast Reactors. In an effort to make these reactors more economic, the fuel is required to stay in the reactor for extended periods of time; the longer the fuel stays within the core, the more fertile material is converted into usable fissile material. However, as burnup of the fuel-rod increases, so does the internal pressure buildup due to gaseous fission products. In order to reach the 30 year lifetime requirements of some reactor designs, the fuel pins must have a vented-type design to allow the buildup of fission products to escape. The present work aims to progress the understanding of the feasibility and safety issues related to gas reactors that incorporate vented fuel. The work was separated into three different work-scopes: 1. Quantitatively determine fission gas release from uranium carbide in a representative helium cooled fast reactor; 2. Model the fission gas behavior, transport, and collection in a Fission Product Vent System; and, 3. Perform a safety analysis of the Fission Product Vent System. Each task relied on results from the previous task, culminating in a limited scope Probabilistic Risk Assessment (PRA) of the Fission Product Vent System. Within each task, many key parameters lack the fidelity needed for comprehensive or accurate analysis. In the process of completing each task, the data or methods that were lacking were identified and compiled in a Gap Analysis included at the end of the report.

  16. 46 CFR 38.20-1 - Venting-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Venting-T/ALL. 38.20-1 Section 38.20-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Venting and Ventilation § 38.20-1 Venting—T/ALL. (a) Each safety relief valve installed on a cargo tank shall be connected to...

  17. 46 CFR 38.20-5 - Venting-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Venting-T/ALL. 38.20-5 Section 38.20-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Venting and Ventilation § 38.20-5 Venting—T/ALL. (a) Safety relief valves on cargo tanks in barges may be connected...

  18. 40 CFR 264.1032 - Standards: Process vents.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Air Emission Standards for Process Vents § 264.1032 Standards: Process vents. (a) The owner or... evaporation, solvent extraction, or air or steam stripping operations managing hazardous wastes with...

  19. 40 CFR 264.1032 - Standards: Process vents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Air Emission Standards for Process Vents § 264.1032 Standards: Process vents. (a) The owner or... evaporation, solvent extraction, or air or steam stripping operations managing hazardous wastes with...

  20. 40 CFR 264.1032 - Standards: Process vents.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Air Emission Standards for Process Vents § 264.1032 Standards: Process vents. (a) The owner or... evaporation, solvent extraction, or air or steam stripping operations managing hazardous wastes with...

  1. 40 CFR 265.1032 - Standards: Process vents.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Air Emission Standards for Process Vents § 265.1032 Standards: Process vents. (a) The...-film evaporation, solvent extraction or -air or steam stripping operations man-aging haz-ard-ous...

  2. 40 CFR 264.1032 - Standards: Process vents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Air Emission Standards for Process Vents § 264.1032 Standards: Process vents. (a) The owner or... evaporation, solvent extraction, or air or steam stripping operations managing hazardous wastes with...

  3. 40 CFR 265.1032 - Standards: Process vents.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Air Emission Standards for Process Vents § 265.1032 Standards: Process vents. (a) The...-film evaporation, solvent extraction or -air or steam stripping operations man-aging haz-ard-ous...

  4. 40 CFR 265.1032 - Standards: Process vents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Air Emission Standards for Process Vents § 265.1032 Standards: Process vents. (a) The...-film evaporation, solvent extraction or -air or steam stripping operations man-aging haz-ard-ous...

  5. 40 CFR 264.1032 - Standards: Process vents.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Air Emission Standards for Process Vents § 264.1032 Standards: Process vents. (a) The owner or... evaporation, solvent extraction, or air or steam stripping operations managing hazardous wastes with...

  6. 40 CFR 265.1032 - Standards: Process vents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Air Emission Standards for Process Vents § 265.1032 Standards: Process vents. (a) The...-film evaporation, solvent extraction or -air or steam stripping operations man-aging haz-ard-ous...

  7. 40 CFR 265.1032 - Standards: Process vents.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Air Emission Standards for Process Vents § 265.1032 Standards: Process vents. (a) The...-film evaporation, solvent extraction or -air or steam stripping operations man-aging haz-ard-ous...

  8. Thermodynamic Vent System Test in a Low Earth Orbit Simulation

    NASA Technical Reports Server (NTRS)

    VanOverbeke, Thomas J.

    2004-01-01

    A thermodynamic vent system for a cryogenic nitrogen tank was tested in a vacuum chamber simulating oxygen storage in low earth orbit. The nitrogen tank was surrounded by a cryo-shroud at -40 F. The tank was insulated with two layers of multi-layer insulation. Heat transfer into cryogenic tanks causes phase change and increases tank pressure which must be controlled. A thermodynamic vent system was used to control pressure as the location of vapor is unknown in low gravity and direct venting would be wasteful. The thermodynamic vent system consists of a Joule-Thomson valve and heat exchanger installed on the inlet side of the tank mixer-pump. The combination is used to extract thermal energy from the tank fluid, reducing temperature and ullage pressure. The system was sized so that the tank mixer-pump operated a small fraction of the time to limit motor heating. Initially the mixer used sub-cooled liquid to cool the liquid-vapor interface inducing condensation and pressure reduction. Later, the thermodynamic vent system was used. Pressure cycles were performed until steady-state operation was demonstrated. Three test runs were conducted at tank fills of 97, 80, and 63 percent. Each test was begun with a boil-off test to determine heat transfer into the tank. The lower tank fills had time averaged vent rates very close to steady-state boil-off rates showing the thermodynamic vent system was nearly as efficient as direct venting in normal gravity.

  9. 46 CFR 38.20-5 - Venting-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Venting-T/ALL. 38.20-5 Section 38.20-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Venting and Ventilation § 38.20-5 Venting—T/ALL. (a) Safety relief valves on cargo tanks in barges may be connected...

  10. 46 CFR 38.20-5 - Venting-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Venting-T/ALL. 38.20-5 Section 38.20-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Venting and Ventilation § 38.20-5 Venting—T/ALL. (a) Safety relief valves on cargo tanks in barges may be connected...

  11. 46 CFR 38.20-5 - Venting-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Venting-T/ALL. 38.20-5 Section 38.20-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Venting and Ventilation § 38.20-5 Venting—T/ALL. (a) Safety relief valves on cargo tanks in barges may be connected...

  12. 46 CFR 38.20-5 - Venting-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Venting-T/ALL. 38.20-5 Section 38.20-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Venting and Ventilation § 38.20-5 Venting—T/ALL. (a) Safety relief valves on cargo tanks in barges may be connected...

  13. Hydrogen Vent Ground Umbilical Quick Disconnect - Flight Seal Advanced Development

    NASA Technical Reports Server (NTRS)

    Girard, Doug; Jankowski, Fred; Minich, Mark C.; Yu, Weiping

    2012-01-01

    This project is a team effort between NASA Engineering (NE) and Team QNA Engineering personnel to provide support for the Umbilical Systems Development project which is funded by Advanced Exploration Systems (AES) and 21st Century Launch Complex. Specifically, this project seeks to develop a new interface between the PPBE baselined Legacy SSP LH2 Vent Arm QD probe and SLS vent seal.

  14. 46 CFR 182.450 - Vent pipes for fuel tanks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... (b) The net cross sectional area of the vent pipe for a gasoline fuel tank must not be less than that... thickness, 20 gauge), except that, where the tank is filled under pressure, the net cross sectional area of the vent pipe must be not less than that of the fill pipe. (c) The minimum net cross sectional area...

  15. 46 CFR 182.450 - Vent pipes for fuel tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... (b) The net cross sectional area of the vent pipe for a gasoline fuel tank must not be less than that... thickness, 20 gauge), except that, where the tank is filled under pressure, the net cross sectional area of the vent pipe must be not less than that of the fill pipe. (c) The minimum net cross sectional area...

  16. Antarctic marine biodiversity and deep-sea hydrothermal vents.

    PubMed

    Chown, Steven L

    2012-01-01

    The diversity of many marine benthic groups is unlike that of most other taxa. Rather than declining from the tropics to the poles, much of the benthos shows high diversity in the Southern Ocean. Moreover, many species are unique to the Antarctic region. Recent work has shown that this is also true of the communities of Antarctic deep-sea hydrothermal vents. Vent ecosystems have been documented from many sites across the globe, associated with the thermally and chemically variable habitats found around these, typically high temperature, streams that are rich in reduced compounds and polymetallic sulphides. The animal communities of the East Scotia Ridge vent ecosystems are very different to those elsewhere, though the microbiota, which form the basis of vent food webs, show less differentiation. Much of the biological significance of deep-sea hydrothermal vents lies in their biodiversity, the diverse biochemistry of their bacteria, the remarkable symbioses among many of the marine animals and these bacteria, and the prospects that investigations of these systems hold for understanding the conditions that may have led to the first appearance of life. The discovery of diverse and unusual Antarctic hydrothermal vent ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic vents south of 60°S benefit from automatic conservation under the Convention on the Conservation of Antarctic Marine Living Resources and the Antarctic Treaty. Other deep-sea hydrothermal vents located in international waters are not protected and may be threatened by growing interests in deep-sea mining.

  17. Where are the undiscovered hydrothermal vents on oceanic spreading ridges?

    NASA Astrophysics Data System (ADS)

    Beaulieu, Stace E.; Baker, Edward T.; German, Christopher R.

    2015-11-01

    In nearly four decades since the discovery of deep-sea vents, one-third of the length of global oceanic spreading ridges has been surveyed for hydrothermal activity. Active submarine vent fields are now known along the boundaries of 46 out of 52 recognized tectonic plates. Hydrothermal survey efforts over the most recent decade were sparked by national and commercial interests in the mineral resource potential of seafloor hydrothermal deposits, as well as by academic research. Here we incorporate recent data for back-arc spreading centers and ultraslow- and slow-spreading mid-ocean ridges (MORs) to revise a linear equation relating the frequency of vent fields along oceanic spreading ridges to spreading rate. We apply this equation globally to predict a total number of vent fields on spreading ridges, which suggests that ~900 vent fields remain to be discovered. Almost half of these undiscovered vent fields (comparable to the total of all vent fields discovered during 35 years of research) are likely to occur at MORs with full spreading rates less than 60 mm/yr. We then apply the equation regionally to predict where these hydrothermal vents may be discovered with respect to plate boundaries and national jurisdiction, with the majority expected to occur outside of states' exclusive economic zones. We hope that these predictions will prove useful to the community in the future, in helping to shape continuing ridge-crest exploration.

  18. Hermetically sealed galvanic cell having safety vent construction

    SciTech Connect

    Chaney, E.J. Jr.

    1984-12-04

    An hermetically sealed galvanic cell having a safety vent assembly comprising a housing having a portion which is inwardly depressed and flexible, which portion surrounds an aperture. The aperture is filled with a layer of glass or ceramic material thus producing an hermetically sealed cell which exhibits increased mechanical strength coupled with reliable venting.

  19. An authoritative global database for active submarine hydrothermal vent fields

    NASA Astrophysics Data System (ADS)

    Beaulieu, Stace E.; Baker, Edward T.; German, Christopher R.; Maffei, Andrew

    2013-11-01

    The InterRidge Vents Database is available online as the authoritative reference for locations of active submarine hydrothermal vent fields. Here we describe the revision of the database to an open source content management system and conduct a meta-analysis of the global distribution of known active vent fields. The number of known active vent fields has almost doubled in the past decade (521 as of year 2009), with about half visually confirmed and others inferred active from physical and chemical clues. Although previously known mainly from mid-ocean ridges (MORs), active vent fields at MORs now comprise only half of the total known, with about a quarter each now known at volcanic arcs and back-arc spreading centers. Discoveries in arc and back-arc settings resulted in an increase in known vent fields within exclusive economic zones, consequently reducing the proportion known in high seas to one third. The increase in known vent fields reflects a number of factors, including increased national and commercial interests in seafloor hydrothermal deposits as mineral resources. The purpose of the database now extends beyond academic research and education and into marine policy and management, with at least 18% of known vent fields in areas granted or pending applications for mineral prospecting and 8% in marine protected areas.

  20. 40 CFR 63.1254 - Standards: Process vents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Standards: Process vents. 63.1254... Standards for Pharmaceuticals Production § 63.1254 Standards: Process vents. (a) Existing sources. For each...-based emission reduction requirement. (i) Uncontrolled HAP emissions from the sum of all process...

  1. 40 CFR 63.983 - Closed vent systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... System or a Process § 63.983 Closed vent systems. (a) Closed vent system equipment and operating... operate a flow indicator that is capable of taking periodic readings. Records shall be generated as... indicator is used, take a reading at least once every 15 minutes. (ii) If the bypass line valve is...

  2. Deep-sea primary production at the Galapagos hydrothermal vents

    SciTech Connect

    Karl, D.M.; Wirsen, C.O.; Jannasch, H.W.

    1980-03-21

    Dense animal populations surrounding recently discovered hydrothermal vents at the Galapagos Rift sea-floor spreading center, 2550 meters deep, are probably sustained by microbial primary production. Energy in the form of geothermically reduced sulfur compounds emitted from the vents is liberated during oxidation and used for the reduction of carbon dioxide to organic matter by chemosynthetic bacteria.

  3. 46 CFR 38.20-1 - Venting-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... special conditions will prevent the vent line header outlets being permanently installed at a height above... such that the back pressure in the relief valve discharge lines shall not be more than 10 percent of... extremely large diameter vent pipe, the back pressure may exceed 10 percent provided: (1) The pressure...

  4. 46 CFR 153.1500 - Venting system rupture disks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....1500 Venting system rupture disks. The master shall ensure that a relief valve exposed to a cargo after the failure of a rupture disk or breaking pin is cleaned and operates properly before the next cargo... 46 Shipping 5 2010-10-01 2010-10-01 false Venting system rupture disks. 153.1500 Section...

  5. 46 CFR 153.1500 - Venting system rupture disks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....1500 Venting system rupture disks. The master shall ensure that a relief valve exposed to a cargo after the failure of a rupture disk or breaking pin is cleaned and operates properly before the next cargo... 46 Shipping 5 2012-10-01 2012-10-01 false Venting system rupture disks. 153.1500 Section...

  6. 46 CFR 153.1500 - Venting system rupture disks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....1500 Venting system rupture disks. The master shall ensure that a relief valve exposed to a cargo after the failure of a rupture disk or breaking pin is cleaned and operates properly before the next cargo... 46 Shipping 5 2011-10-01 2011-10-01 false Venting system rupture disks. 153.1500 Section...

  7. 46 CFR 153.1500 - Venting system rupture disks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....1500 Venting system rupture disks. The master shall ensure that a relief valve exposed to a cargo after the failure of a rupture disk or breaking pin is cleaned and operates properly before the next cargo... 46 Shipping 5 2014-10-01 2014-10-01 false Venting system rupture disks. 153.1500 Section...

  8. 46 CFR 153.1500 - Venting system rupture disks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....1500 Venting system rupture disks. The master shall ensure that a relief valve exposed to a cargo after the failure of a rupture disk or breaking pin is cleaned and operates properly before the next cargo... 46 Shipping 5 2013-10-01 2013-10-01 false Venting system rupture disks. 153.1500 Section...

  9. Vents to the north of the south elevation, note the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Vents to the north of the south elevation, note the hooded vents along the elevation - Over-the-Horizon Backscatter Radar Network, Christmas Valley Radar Site Transmit Sector Six Transmitter Building, On unnamed road west of Lost Forest Road, Christmas Valley, Lake County, OR

  10. Vented piston seal prevents fluid leakage between two chambers

    NASA Technical Reports Server (NTRS)

    Mac Glashan, W. F.; Morrison, R.

    1964-01-01

    To prevent fluid leakage around piston seals separating two fluids under differential pressure, a venting system has been devised. Two methods may be used for venting seals through internal passages to an external low-pressure area, O-ring or split-ring seals.

  11. Dispersal mechanisms of deep-sea hydrothermal vent fauna

    NASA Astrophysics Data System (ADS)

    Mullineaux, Lauren S.; France, Scott C.

    Species living at hydrothermal vents are faced with the problem of how to maintain their populations in a habitat that is patchy and ephemeral on time scales as short as decades. Because active hydrothermal venting is essential for the survival of vent communities, species must be capable of dispersing to a new location before a local vent closes. Many vent species are sessile or have limited mobility as adults, so dispersal can occur only in the larval stage of their life cycle. Larvae are typically small and are relatively weak swimmers, but they can potentially be transported long distances in oceanic currents. The range and frequency of larval dispersal influence how far away and how quickly a species can colonize a new vent habitat (i.e., will it be an opportunistic pioneer colonist or a later arrival), and constrain the amount of genetic exchange among existing vent populations. If dispersal between vent habitats is consistently impeded by geographic or physiological barriers, then gene flow will be reduced. Such barriers to dispersal can result in setting boundaries to a species' range and in genetic differentiation between previously interbreeding populations.

  12. Convection venting lensed reflector-type compact fluorescent lamp system

    DOEpatents

    Pelton, B.A.; Siminovitch, M.

    1997-07-29

    Disclosed herein is a fluorescent lamp housing assembly capable of providing convection cooling to the lamp and the ballast. The lens of the present invention includes two distinct portions, a central portion and an apertured portion. The housing assembly further includes apertures so that air mass is able to freely move up through the assembly and out ventilation apertures. 12 figs.

  13. Convection venting lensed reflector-type compact fluorescent lamp system

    DOEpatents

    Pelton, Bruce A.; Siminovitch, Michael

    1997-01-01

    Disclosed herein is a fluorescent lamp housing assembly capable of providing convection cooling to the lamp and the ballast. The lens of the present invention includes two distinct portions, a central portion and an apertured portion. The housing assembly further includes apertures so that air mass is able to freely move up through the assembly and out ventilation apertures.

  14. Assessment of Literature Related to Combustion Appliance Venting Systems

    SciTech Connect

    Rapp, V. H.; Less, B. D.; Singer, B. C.; Stratton, J. C.; Wray, C. P.

    2015-02-01

    In many residential building retrofit programs, air tightening to increase energy efficiency is often constrained by safety concerns with naturally vented combustion appliances. Tighter residential buildings more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spill combustion exhaust into the living space. Several measures, such as installation guidelines, vent sizing codes, and combustion safety diagnostics, are in place with the intent to prevent backdrafting and combustion spillage, but the diagnostics conflict and the risk mitigation objective is inconsistent. This literature review summarizes the metrics and diagnostics used to assess combustion safety, documents their technical basis, and investigates their risk mitigations. It compiles information from the following: codes for combustion appliance venting and installation; standards and guidelines for combustion safety diagnostics; research evaluating combustion safety diagnostics; research investigating wind effects on building depressurization and venting; and software for simulating vent system performance.

  15. In situ venting of jet fuel-contaminated soil

    SciTech Connect

    Elliott, M.G.; DePaoli, D.W.

    1989-01-01

    The Air Force Engineering and Services center is performing a field demonstration of in situ soil venting at a 27,000-gallon jet fuel spill site at Hill AFB UT. In situ soil venting is a soil cleanup technique which uses vacuum blowers to pull large volumes of air through contaminated soil. The air flow sweeps out the soil gas, disrupting the equilibrium existing between the contaminants on the soil and in the vapor. This causes volatilization of the contaminants and subsequent removal in the air stream. In situ soil venting has been used for removing volatile contaminants such as gasoline and trichloroethylene, but a full-scale demonstration for removing jet fuel from soil has not been reported. This paper describes our initial site characterization, the one-vent pilot test, and the design and preliminary results of our full-scale in situ soil venting system. 5 refs., 7 figs.

  16. 40 CFR 63.118 - Process vent provisions-periodic reporting and recordkeeping requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Synthetic Organic Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater § 63.118 Process vent provisions—periodic reporting and recordkeeping requirements....

  17. 40 CFR 63.118 - Process vent provisions-periodic reporting and recordkeeping requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Synthetic Organic Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater § 63.118 Process vent provisions—periodic reporting and recordkeeping requirements....

  18. 40 CFR 63.118 - Process vent provisions-periodic reporting and recordkeeping requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Synthetic Organic Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater § 63.118 Process vent provisions—periodic reporting and recordkeeping requirements....

  19. Trophic regions of a hydrothermal plume dispersing away from an ultramafic-hosted vent-system: Von Damm vent-site, Mid-Cayman Rise

    NASA Astrophysics Data System (ADS)

    Bennett, Sarah A.; Coleman, Max; Huber, Julie A.; Reddington, Emily; Kinsey, James C.; McIntyre, Cameron; Seewald, Jeffrey S.; German, Christopher R.

    2013-02-01

    type</span>="main">Abstract Deep-sea ultramafic-hosted <span class="hlt">vent</span> systems have the potential to provide large amounts of metabolic energy to both autotrophic and heterotrophic microorganisms in their dispersing hydrothermal plumes. Such <span class="hlt">vent</span>-systems release large quantities of hydrogen and methane to the water column, both of which can be exploited by autotrophic microorganisms. Carbon cycling in these hydrothermal plumes may, therefore, have an important influence on open-ocean biogeochemistry. In this study, we investigated an ultramafic-hosted system on the Mid-Cayman Rise, emitting metal-poor and hydrogen sulfide-, methane-, and hydrogen-rich hydrothermal fluids. Total organic carbon concentrations in the plume ranged between 42.1 and 51.1 μM (background = 43.2 ± 0.7 μM (n = 5)) and near-field plume samples with elevated methane concentrations imply the presence of chemoautotrophic primary production and in particular methanotrophy. In parts of the plume characterized by persistent potential temperature anomalies but lacking elevated methane concentrations, we found elevated organic carbon concentrations of up to 51.1 μM, most likely resulting from the presence of heterotrophic communities, their extracellular products and <span class="hlt">vent</span> larvae. Elevated carbon concentrations up to 47.4 μM were detected even in far-field plume samples. Within the Von Damm hydrothermal plume, we have used our data to hypothesize a microbial food web in which chemoautotrophy supports a heterotrophic community of microorganisms. Such an active microbial food web would provide a source of labile organic carbon to the deep ocean that should be considered in any future studies evaluating sources and sinks of carbon from hydrothermal <span class="hlt">venting</span> to the deep ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70176784','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70176784"><span id="translatedtitle">Submarine radial <span class="hlt">vents</span> on Mauna Loa Volcano, Hawai'i</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wanless, V. Dorsey; Garcia, M.O.; Trusdell, F.A.; Rhodes, J.M.; Norman, M.D.; Weis, Dominique; Fornari, D.J.; Kurz, M.D.; Guillou, Herve</p> <p>2006-01-01</p> <p>A 2002 multibeam sonar survey of Mauna Loa's western flank revealed ten submarine radial <span class="hlt">vents</span> and three submarine lava flows. Only one submarine radial <span class="hlt">vent</span> was known previously. The ages of these <span class="hlt">vents</span> are constrained by eyewitness accounts, geologic relationships, Mn-Fe coatings, and geochemical stratigraphy; they range from 128 years B.P. to possibly 47 ka. Eight of the radial <span class="hlt">vents</span> produced degassed lavas despite eruption in water depths sufficient to inhibit sulfur degassing. These <span class="hlt">vents</span> formed truncated cones and short lava flows. Two <span class="hlt">vents</span> produced undegassed lavas that created “irregular” cones and longer lava flows. Compositionally and isotopically, the submarine radial <span class="hlt">vent</span> lavas are typical of Mauna Loa lavas, except two cones that erupted alkalic lavas. He-Sr isotopes for the radial <span class="hlt">vent</span> lavas follow Mauna Loa's evolutionary trend. The compositional and isotopic heterogeneity of these lavas indicates most had distinct parental magmas. Bathymetry and acoustic backscatter results, along with photography and sampling during four JASON2 dives, are used to produce a detailed geologic map to evaluate Mauna Loa's submarine geologic history. The new map shows that the 1877 submarine eruption was much larger than previously thought, resulting in a 10% increase for recent volcanism. Furthermore, although alkalic lavas were found at two radial <span class="hlt">vents</span>, there is no systematic increase in alkalinity among these or other Mauna Loa lavas as expected for a dying volcano. These results refute an interpretation that Mauna Loa's volcanism is waning. The submarine radial <span class="hlt">vents</span> and flows cover 29 km2 of seafloor and comprise a total volume of ∼2×109 m3 of lava, reinforcing the idea that submarine lava eruptions are important in the growth of oceanic island volcanoes even after they emerged above sea level.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016HydJ...24..649C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016HydJ...24..649C"><span id="translatedtitle">Land subsidence and earth <span class="hlt">fissures</span> in south-central and southern Arizona, USA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Conway, Brian D.</p> <p>2016-05-01</p> <p>Land subsidence due to groundwater overdraft has been an ongoing problem in south-central and southern Arizona (USA) since the 1940s. The first earth <span class="hlt">fissure</span> attributed to excessive groundwater withdrawal was discovered in the early 1950s near Picacho. In some areas of the state, groundwater-level declines of more than 150 m have resulted in extensive land subsidence and earth <span class="hlt">fissuring</span>. Land subsidence in excess of 5.7 m has been documented in both western metropolitan Phoenix and Eloy. The Arizona Department of Water Resources (ADWR) has been monitoring land subsidence since 2002 using interferometric synthetic aperture radar (InSAR) and since 1998 using a global navigation satellite system (GNSS). The ADWR InSAR program has identified more than 25 individual land subsidence features that cover an area of more than 7,300 km2. Using InSAR data in conjunction with groundwater-level datasets, ADWR is able to monitor land subsidence areas as well as identify areas that may require additional monitoring. One area of particular concern is the Willcox groundwater basin in southeastern Arizona, which is the focus of this paper. The area is experiencing rapid groundwater declines, as much as 32.1 m during 2005-2014 (the largest land subsidence rate in Arizona State—up to 12 cm/year), and a large number of earth <span class="hlt">fissures</span>. The declining groundwater levels in Arizona are a challenge for both future groundwater availability and mitigating land subsidence associated with these declines. ADWR's InSAR program will continue to be a critical tool for monitoring land subsidence due to excessive groundwater withdrawal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4890055','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4890055"><span id="translatedtitle">Ability of Pit and <span class="hlt">Fissure</span> Sealant-containing Amorphous Calcium Phosphate to inhibit Enamel Demineralization</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Owais, Arwa I; Kawaja, Wasan</p> <p>2016-01-01</p> <p>ABSTRACT Aim: To evaluate the effect of amorphous calcium phosphate (ACP)-containing pit and <span class="hlt">fissure</span> sealant on inhibition of enamel demineralization in vitro. Materials and methods: Enamel specimens (n = 75) were prepared using freshly extracted noncarious human third molars. Box-shaped cavities (8 × 2 × 2 mm) on the buccal or lingual surfaces were prepared and restored with resin-based sealant (Concise™), ACP-containing sealant (Aegis®) or fluoride-containing sealant (Conseal-F™). The samples were acid challenged in a demineralizing solution of 50 mmol/l lactic acid at pH 5.0 for 4 days. The change in enamel microhardness (ASuH) was calculated. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey’s post hoc test. Results: The mean SuH0 (±SD) (in Vicker’s unit) prior to the acid challenge was: Concise™ (318.83 ± 33.86), Aegis® (331.03 ± 21.52), Conseal-F™ (310.12 ± 34.31). Following the acid challenge, the values dropped in all groups and ASuH (±SD) values were 269.17 ± 47.49, 151.39 ± 23.96 and 175.79 ± 32.39 respectively. Conclusion: The ACP-containing pit and <span class="hlt">fissure</span> sealant has the potential to inhibit enamel demineralization. How to cite this article: Zawaideh FI, Owais AI, Kawaja W. Ability of pit and <span class="hlt">fissure</span> sealant-containing amorphous calcium phosphate to inhibit enamel demineralization. Int J Clin Pediatr Dent 2016;9(1):10-14. PMID:27274148</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17024941','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17024941"><span id="translatedtitle">Performance of a conventional sealant and a flowable composite on minimally invasive prepared <span class="hlt">fissures</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Francescut, Paola; Lussi, Adrian</p> <p>2006-01-01</p> <p>Three different <span class="hlt">fissure</span> preparation procedures were tested and compared to the non-invasive approach using a conventional unfilled sealant and a flowable composite. Eighty permanent molars were selected and divided into 4 groups of 20 teeth each. All the teeth were split into 2 halves, and the exposed <span class="hlt">fissures</span> were photographed under a microscope (35x) before and after being prepared using the following methods: (I) Er:YAG laser (KEY Laser, KaVo) 600 mJ pulse energy, 6 Hz; (II) diamond bur; (III) Er: YAG laser (KEY Laser, KaVo) 200 mJ pulse energy, 4 Hz; (IV) Control group: Powder jet cleaner (Prophyflex, KaVo, Germany). The pre-and postimages were superimposed in order to evaluate the amount of hard tissue removed. Ten teeth in each group were then acid etched and sealed with an unfilled sealant (Delton opaque, Dentsply), while the remaining 10 teeth were acid etched, primed and bonded (Prime & Bond NT, Dentsply) and sealed with a flowable composite (X-flow, DeTrey, Dentsply). Material penetration and microleakage were evaluated after thermocycling (5000 cycles) and staining with methylene blue 5%. ANOVA and Mann-Whitney tests were applied for statistical analysis. The laser 600 mJ and bur eliminated the greatest amount of hard tissue. The control teeth presented the least microleakage when sealed with Delton or X-flow. A correlation between material penetration and microleakage could not be statistically confirmed. Mechanical preparation prior to <span class="hlt">fissure</span> sealing did not enhance the final performance of the sealant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/001130.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/001130.htm"><span id="translatedtitle">Anal <span class="hlt">fissure</span></span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... cream, if pain interferes with normal bowel movements Petroleum jelly Zinc oxide, 1% hydrocortisone cream, Preparation H, ... is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fascrs.org/patients/disease-condition/anal-fissure','NIH-MEDLINEPLUS'); return false;" href="https://www.fascrs.org/patients/disease-condition/anal-fissure"><span id="translatedtitle">Anal <span class="hlt">Fissure</span></span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>Skip to main content ASCRS Patients Educational Resources Diseases and Conditions Patient Education Library Patient Success Stories Treatments and Screening Resources Find a Surgeon Hereditary Colorectal Cancer Registries Helpful Links Physicians ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.aaom.com/index.php?option=com_content&view=article&id=130:fissured-tongue&catid=22:patient-condition-information&Itemid=120','NIH-MEDLINEPLUS'); return false;" href="http://www.aaom.com/index.php?option=com_content&view=article&id=130:fissured-tongue&catid=22:patient-condition-information&Itemid=120"><span id="translatedtitle"><span class="hlt">Fissured</span> Tongue</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... Executive Committee Board of Trustees Governance Past Presidents Staff/Contact History Awards Our Partners Membership Membership Categories Renew Your Membership Login Fellowship Academic Fellowship Affiliate Fellowship (AFAOM) Application Process Fellowship Study ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/184132','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/184132"><span id="translatedtitle">Addition of fluoride to pit and <span class="hlt">fissure</span> sealants--a feasibility study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Swartz, M L; Phillips, R W; Norman, R D; Elliason, S; Rhodes, B F; Clark, H E</p> <p>1976-01-01</p> <p>The data obtained in this in vitro study indicate that contact with pit and <span class="hlt">fissure</span> sealants to which NaF has been added in amounts ranging from 2 to 5% substantially increases the fluoride content of the enamel and reduces its solubility in acid. The properties of the materials do not seem to be impaired by the addition of fluoride in these amounts. It thus appears that this approach to providing a backup anticariogenic mechanism may, indeed, be feasible. However, further investigation must be done to confirm the anticariogenic effect and to establish the most efficacious means of fluoride incorporation in the materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25710951','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25710951"><span id="translatedtitle">Treating pit-and-<span class="hlt">fissure</span> caries: a systematic review and network meta-analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schwendicke, F; Jäger, A M; Paris, S; Hsu, L Y; Tu, Y K</p> <p>2015-04-01</p> <p>For shallow or moderately deep pit-and-<span class="hlt">fissure</span> lesions, various treatment options are available: (1) noninvasive treatments (e.g., fluoride application, antibacterial treatments, oral hygiene advice) avoid any dental hard tissue removal; (2) microinvasive treatments (e.g., sealing) remove only a few micrometers of hard tissues by etching; and minimally invasive methods (e.g., "preventive" resin/sealant restoration) remove carious dentin but avoid sacrificing sound tissues. We aimed at systematically reviewing and comparing these strategies for treating pit-and-<span class="hlt">fissure</span> lesions in permanent teeth using network meta-analysis. Randomized or nonrandomized clinical trials investigating shallow or moderately deep primary caries lesions in <span class="hlt">fissured</span> or pitted surfaces were included. We compared the risk of requiring invasive treatments or any retreatments in noninvasive, microinvasive, and minimally invasive treated lesions; untreated lesions were used as controls. Five electronic databases were systematically screened up to September 2013 and cross-referencing performed. Pairwise and network meta-analyses were performed and odds ratios and 95% confidence intervals (CI) calculated. Certainty of estimates was evaluated via GRADE criteria. From a total of 2,214 identified records, 14 studies representing 1,440 patients with 3,551 treated lesions were included. Pairwise meta-analysis found microinvasive and minimally invasive treated lesions to require less invasive retreatments than control lesions (odds ratios [95% confidence intervals]: 0.13 [0.07 to 0.26], 0.13 [0.03 to 0.50], respectively), whereas the estimate for noninvasively treated lesions remained nonsignificant (0.64 [0.39 to 1.06]). These findings were reflected in the strategy ranking stemming from network meta-analysis (first, minimally invasive; second, microinvasive; third, noninvasive). However, microinvasive treatment required significantly more total retreatments (including resealing) than minimally or</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6762Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6762Z"><span id="translatedtitle">3D model of fault and <span class="hlt">fissures</span> structure of the Kovdor Baddeleyite-Apatite-Magnetite Deposit (NE of the Fennoscandian Shield)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhirov, Dmitry; Klimov, Sergey</p> <p>2015-04-01</p> <p>The Kovdor baddeleyite-apatite-magnetite deposit (KBAMD) is represented by a large vertical ore body and is located in the southwestern part of the Kovdor ultramafic-alkaline central-<span class="hlt">type</span> intrusion. The intrusion represents a concentrically zoned complex of rocks with an oval shape in plan, and straight zoning, which complies with the injection and displacement of each of further magma phases from the center towards the periphery. The operation of the deposit in open pits started in 1962, and nowadays, it has produced over 500,000,000 tons of ore. This is one of the largest open pits in the Kola region, which is ca. 2 km long, 1.8 km wide, and over 400 m deep. Regular structural studies has been carried out since late 1970. A unique massif of spatial data has been accumulated so far to include over 25,000 measurements of <span class="hlt">fissures</span> and faults from the surface, ca. 20,000 measurements of <span class="hlt">fissures</span> in the oriented drill core (over 18 km) etc. Using this data base the 3D model of fault and <span class="hlt">fissures</span> structure was designed. The analysis of one has resulted in the identification of a series of laws and features, which are necessary to be taken into account when designing a deep open pit and mining is carried out. These are mainly aspects concerning the origin, kinematics, mechanics and ratio of spatial extension of various fault systems, variation of their parameters at deep horizons, features of a modern stress field in the country rocks, etc. The 3D model has allowed to divide the whole fracture / <span class="hlt">fissure</span> systems of the massif rocks into 2 large groups: prototectonic system of joints, including cracks of 'liquid magmatic (carbonatite stage) contraction genesis', and newly formed faults due to the superimposed tectonic stages. With regard to the deposit scale, these are characterized as intraformational and transformational, respectively. Each group shows a set (an assemblage) of fault systems with unique features and signs, as well as regular interconnections. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015PIAHS.372..305Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015PIAHS.372..305Z&link_type=ABSTRACT"><span id="translatedtitle">Different scale land subsidence and ground <span class="hlt">fissure</span> monitoring with multiple InSAR techniques over Fenwei basin, China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, C.; Zhang, Q.; Yang, C.; Zhang, J.; Zhu, W.; Qu, F.; Liu, Y.</p> <p>2015-11-01</p> <p>Fenwei basin, China, composed by several sub-basins, has been suffering severe geo-hazards in last 60 years, including large scale land subsidence and small scale ground <span class="hlt">fissure</span>, which caused serious infrastructure damages and property losses. In this paper, we apply different InSAR techniques with different SAR data to monitor these hazards. Firstly, combined small baseline subset (SBAS) InSAR method and persistent scatterers (PS) InSAR method is used to multi-track Envisat ASAR data to retrieve the large scale land subsidence covering entire Fenwei basin, from which different land subsidence magnitudes are analyzed of different sub-basins. Secondly, PS-InSAR method is used to monitor the small scale ground <span class="hlt">fissure</span> deformation in Yuncheng basin, where different spatial deformation gradient can be clearly discovered. Lastly, different track SAR data are contributed to retrieve two-dimensional deformation in both land subsidence and ground <span class="hlt">fissure</span> region, Xi'an, China, which can be benefitial to explain the occurrence of ground <span class="hlt">fissure</span> and the correlation between land subsidence and ground <span class="hlt">fissure</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.V21A2750K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.V21A2750K"><span id="translatedtitle">1891 Submarine eruption of Foerstner volcano (Pantelleria, Sicily) : insights into the <span class="hlt">vent</span> structure of basaltic balloon eruptions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kelly, J. T.; Carey, S.; Bell, K. L.; Rosi, M.; Marani, M.; Roman, C.; Pistolesi, M.; Baker, E. T.</p> <p>2012-12-01</p> <p> second, previously unknown <span class="hlt">vent</span> located north of Foerstner volcano at a depth of around 350 meters. Given the close proximity of these two <span class="hlt">vents</span>, the differences in deposit <span class="hlt">types</span> may be due to changing eruption style as a function of water depth. The abundant pillow flow lobes observed at the northern <span class="hlt">vent</span> are most likely the result of more effusive eruptions occurring in deeper water (350 m) whereas the dominantly fragmental nature of material in the main southern <span class="hlt">vent</span> indicates more vigorous explosive activity at shallower levels (250 m). Based on the nature of deposits found at the <span class="hlt">vent</span> areas, the basaltic balloons of the 1891 Foerstner eruption are suspected to be a result of both coarse, localized fire fountaining activity and detachment from gas-charged flow lobes. The larger and shallower southern <span class="hlt">vent</span> area is likely to have been the main source of the basaltic balloons observed on the surface during the 1891 eruption. A review of other historic eruptions that have produced basaltic balloons suggests that this style of activity is likely to be restricted to a rather narrow range of water depths and thus recognition of the distinct deposits produced by this <span class="hlt">type</span> of activity in ancient deposits could help place important paleodepth constraints on volcaniclastic sequences.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080047210','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080047210"><span id="translatedtitle">Deep-Sea Hydrothermal-<span class="hlt">Vent</span> Sampler</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Behar, Alberto E.; Venkateswaran, Kasthur; Matthews, Jaret B.</p> <p>2008-01-01</p> <p>An apparatus is being developed for sampling water for signs of microbial life in an ocean hydrothermal <span class="hlt">vent</span> at a depth of as much as 6.5 km. Heretofore, evidence of microbial life in deep-sea hydrothermal <span class="hlt">vents</span> has been elusive and difficult to validate. Because of the extreme conditions in these environments (high pressures and temperatures often in excess of 300 C), deep-sea hydrothermal- <span class="hlt">vent</span> samplers must be robust. Because of the presumed low density of biomass of these environments, samplers must be capable of collecting water samples of significant volume. It is also essential to prevent contamination of samples by microbes entrained from surrounding waters. Prior to the development of the present apparatus, no sampling device was capable of satisfying these requirements. The apparatus (see figure) includes an intake equipped with a temperature probe, plus several other temperature probes located away from the intake. The readings from the temperature probes are utilized in conjunction with readings from flowmeters to determine the position of the intake relative to the hydrothermal plume and, thereby, to position the intake to sample directly from the plume. Because it is necessary to collect large samples of water in order to obtain sufficient microbial biomass but it is not practical to retain all the water from the samples, four filter arrays are used to concentrate the microbial biomass (which is assumed to consist of particles larger than 0.2 m) into smaller volumes. The apparatus can collect multiple samples per dive and is designed to process a total volume of 10 L of <span class="hlt">vent</span> fluid, of which most passes through the filters, leaving a total possibly-microbe-containing sample volume of 200 mL remaining in filters. A rigid titanium nose at the intake is used for cooling the sample water before it enters a flexible inlet hose connected to a pump. As the water passes through the titanium nose, it must be cooled to a temperature that is above a mineral</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015DPS....4741003M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015DPS....4741003M"><span id="translatedtitle"><span class="hlt">Venting</span> of CO2 at Enceladus’ Surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matson, Dennis L.; Davies, Ashley G.; Johnson, Torrence V.; Combe, Jean-Philippe; McCord, Tom B.; Radebaugh, Jani</p> <p>2015-11-01</p> <p>Enceladus has CO2 surface deposits in its South Polar Region that have been recently mapped by J.-P. Combe et al. (2015 AGU Fall Meeting). Assuming that these are CO2 frost, we show how they can be formed. We use an ocean-water circulation model [1] that specifies pressure gradients that drive water to the surface from a relatively gas-rich, subsurface ocean. We now examine the movement of CO2 to the surface; formation of shallow CO2 gas pockets in the ice; and the <span class="hlt">venting</span> of CO2, when at least some of the gas freezes to form frost. If the local heat flow is known (cf. [2]), then the depths of the corresponding gas pockets can be calculated. References: [1] Matson et al. (2012) Icarus, 221, 53-62. [2] Howett et al. (2011) J. Geophys. Res. 116, E03003. Acknowledgements: AGD thanks the NASA OPR Program for support.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25134364','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25134364"><span id="translatedtitle">One-year clinical evaluation of a Glass Carbomer <span class="hlt">fissure</span> sealant, a preliminary study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gorseta, K; Glavina, D; Borzabadi-Farahani, A; Van Duinen, R N; Skrinjaric, I; Hill, R G; Lynch, E</p> <p>2014-06-01</p> <p>Glass Carbomer is a new generation of restorative material developed from glass-ionomer cements with possibility of gradual mineralization into fluorapatite. The aim of this clinical trial was to investigate the retention of Glass Carbomer <span class="hlt">fissure</span> sealant after 12 months, in comparison to a commonly used conventional resin-based sealant. Forty-eight teeth in 24 patients [mean (SD) = 8 (2.3) years] with well-delineated <span class="hlt">fissure</span> morphology were randomly divided into two equal groups and sealed with Bis-GMA resin-based Helioseal F (group A, Ivoclar Vivadent, Liechtenstein) and Glass Carbomer (group B, Glass Carbomer Sealant, Glass Carbomer Products, Leiden, Netherlands) using the split mouth design. Materials were placed and set according to the manufacturer's instructions using a polymerization unit Bluephase 16i (Vivadent, Liechtenstein). Complete sealant retentions in both groups were 100% and 75% after 6 and 12 months of clinical service, respectively. There were there were no secondary caries lesions in both groups after 6 months; two new carious lesions were detected in both groups after 12 months. The Mann-Whitney U test revealed no significant difference between the two groups at both evaluations points (P > 0.05). Glass Carbomer material showed a similar retention rate when compared with a resin-based sealant. Future studies are required to examine the long-term performance of Glass Carbomer sealants. PMID:25134364</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25642874','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25642874"><span id="translatedtitle">Dermal flap advancement combined with conservative sphincterotomy in the treatment of chronic anal <span class="hlt">fissure</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Theodoropoulos, George E; Spiropoulos, Vasileios; Bramis, Konstantinos; Plastiras, Aris; Zografos, George</p> <p>2015-02-01</p> <p>Lateral internal sphincterotomy (LIS) is considered the surgical treatment of choice for chronic anal <span class="hlt">fissure</span> (CAF). Flap techniques for <span class="hlt">fissure</span> coverage have the advantage of primary wound healing, potentially providing better functional results and faster pain relief. The standard surgical strategy for CAF consisting of conventional LIS (CLIS) up to the dentate line was modified by "tailoring" the LIS to the apex of the CAF, but never greater than 1 cm, and by advancing a dermal flap for coverage of the CAF (LIS + flap) after fissurectomy. Thirty consecutive patients who underwent "LIS + flap" were compared with 32 patients who had been previously treated by CLIS. A modified, trapezoid-like Y-V flap from perianal skin was advanced into the CAF base. Pain at the first postoperative day, pain at defecation during the first week, postoperative use of analgesics, and time for patients' pain relief were significantly less at the "LIS + flap" group (P < 0.01). Objective healing was achieved faster (P < 0.01) and soiling episodes were less (P < 0.05) after "LIS + flap." The addition of a dermal flap after "conservative" LIS resulted in better healing and significantly less postoperative discomfort than the isolated application of CLIS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19234725','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19234725"><span id="translatedtitle">Effects of aging on surface properties and adhesion of Streptococcus mutans on various <span class="hlt">fissure</span> sealants.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bürgers, Ralf; Cariaga, Tashiana; Müller, Rainer; Rosentritt, Martin; Reischl, Udo; Handel, Gerhard; Hahnel, Sebastian</p> <p>2009-12-01</p> <p>The aim of the present study was the quantification of Streptococcus mutans adhesion on ten widely used pit and <span class="hlt">fissure</span> sealant materials and the correlation of these findings to surface roughness (R(a)) and surface free energy (SFE). Additionally, changes in streptococcal adhesion and surface parameters after water immersion and artificial aging have been investigated. Circular specimens of ten <span class="hlt">fissure</span> sealants (seven resin-based composites, two glass ionomers, and one compomer) were made and polished. Surface roughness was determined by perthometer and SFE by goniometer measurements. Sealant materials were incubated with S. mutans suspension (2.5 h, 37 degrees C), and adhering bacteria were quantified by using a biofluorescence assay in combination with an automated plate reader. Surface properties and S. mutans adhesion were measured prior to and after water immersion after 1 and 6 months and after additional thermocycling (5,000 cycles; 5 degrees C/55 degrees C). The tested sealants showed significant differences in S. mutans adhesion prior to and after the applied aging procedures. Aging resulted in slight increases (mostly <0.2 microm) in surface roughness, as well as in significant decreases in SFE and in significantly lower quantities of adhering bacteria. Ketac Bond and UltraSeal XT plus revealed the lowest adhesion potential after artificial aging. In general, the amount of adhering S. mutans was reduced after aging, which may be related to the decline in SFEs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1290813','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1290813"><span id="translatedtitle">Maintenance therapy with unprocessed bran in the prevention of acute anal <span class="hlt">fissure</span> recurrence.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jensen, S L</p> <p>1987-01-01</p> <p>The effect of unprocessed bran in a dose of 5 g three times daily and a dose of 2.5 g three times daily for one year on the recurrence rate of anal <span class="hlt">fissures</span> was studied in a double-blind, placebo-controlled trial in 90 patients with recently healed acute posterior anal <span class="hlt">fissures</span>. Fifteen patients (16.6%) were withdrawn before the code was broken due to failure to follow the trial protocol for various reasons. Significantly fewer recurrences occurred in patients receiving bran 5 g three times daily (recurrence rate 16%, 95% confidence limits, 4.54 to 36.08) when compared with patients receiving bran 2.5 g three times daily (60%; 38.67 to 78.87) (P less than 0.01) and with patients receiving placebo three times daily (68%; 46.50 to 85.05) (P less than 0.01). No significant difference in recurrences was found between patients on bran 2.5 g and those on placebo. PMID:3039130</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3296975','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3296975"><span id="translatedtitle">Botulinum toxin for chronic anal <span class="hlt">fissure</span> after biliopancreatic diversion for morbid obesity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Vanella, Serafino; Brisinda, Giuseppe; Marniga, Gaia; Crocco, Anna; Bianco, Giuseppe; Maria, Giorgio</p> <p>2012-01-01</p> <p>AIM: To study the effect of botulinum toxin in patients with chronic anal <span class="hlt">fissure</span> after biliopancreatic diversion (BPD) for severe obesity. METHODS: Fifty-nine symptomatic adults with chronic anal <span class="hlt">fissure</span> developed after BPD were enrolled in an open label study. The outcome was evaluated clinically and by comparing the pressure of the anal sphincters before and after treatment. All data were analyzed in univariate and multivariate analysis. RESULTS: Two months after treatment, 65.4% of the patients had a healing scar. Only one patient had mild incontinence to flatus that lasted 3 wk after treatment, but this disappeared spontaneously. In the multivariate analysis of the data, two registered months after the treatment, sex (P = 0.01), baseline resting anal pressure (P = 0.02) and resting anal pressure 2 mo after treatment (P < 0.0001) were significantly related to healing rate. CONCLUSION: Botulinum toxin, despite worse results than in non-obese individuals, appears the best alternative to surgery for this group of patients with a high risk of incontinence. PMID:22416176</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3153C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3153C"><span id="translatedtitle">The link between circumferential dikes and eruptive <span class="hlt">fissures</span> around calderas: insights from numerical and analog models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Corbi, Fabio; Rivalta, Eleonora; Pinel, Virginie; Maccaferri, Francesco; Acocella, Valerio</p> <p>2016-04-01</p> <p>Active calderas are seldom associated with circumferential eruptive <span class="hlt">fissures</span> along their rim, but eroded portions of extinct magmatic complexes reveal widespread evidence of circumferential dikes. This discrepancy suggests that, while the conditions to emplace circumferential dikes below volcanoes are easily met, mechanisms must exist to arrest the dikes before they reach the surface. Here we explain this discrepancy with laboratory experiments of air injection into a gelatin medium shaped to mimic a volcanic edifice with caldera. Our models show that the ascending dikes experience a variable degree of deflection, depending on the competition between dike overpressure, Pe, and the forcing induced by the topographic load, Pl. When Pl/Pe = 4.3 - 4.5 the analog dikes proceed almost insensitive to the stress rotation and erupt within the caldera. When Pl/Pe = 4.8 - 5.3 the analog dikes closely propagate orthogonal to the least compressive stress σ3 and stall below the caldera rim in a circumferential arrangement. Progressive buoyancy increase through repeated supply of fluid is fundamental for the occurrence of circumferential <span class="hlt">fissures</span>. Complementary numerical models explain the observed circumferential arrangement and validate the experiments. These results contribute defining the shallow magma transfer and related hazard assessment within calderas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.6212C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.6212C"><span id="translatedtitle">Understanding the link between circumferential dikes and eruptive <span class="hlt">fissures</span> around calderas based on numerical and analog models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Corbi, Fabio; Rivalta, Eleonora; Pinel, Virginie; Maccaferri, Francesco; Acocella, Valerio</p> <p>2016-06-01</p> <p>Active calderas are seldom associated with circumferential eruptive <span class="hlt">fissures</span>, but eroded magmatic complexes reveal widespread circumferential dikes. This suggests that, while the conditions to emplace circumferential dikes are easily met, mechanisms must prevent them from reaching the surface. We explain this discrepancy with experiments of air injection into gelatin shaped as a volcano with caldera. Analog dikes show variable deflection, depending on the competition between overpressure, Pe, and topographic unloading, Pl; when Pl/Pe = 4.8-5.3, the dikes propagate orthogonal to the least compressive stress. Due to the unloading, they become circumferential and stall below the caldera rim; buoyancy is fundamental for the further rise and circumferential <span class="hlt">fissure</span> development. Numerical models quantitatively constrain the stress orientation within the gelatin, explaining the observed circumferential dikes. Our results explain how dikes propagate below the rim of felsic and mafic calderas, but only in the latter they are prone to feed circumferential <span class="hlt">fissures</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21232364','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21232364"><span id="translatedtitle">Biogeography of hydrothermal <span class="hlt">vent</span> communities along seafloor spreading centers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Van Dover, C L</p> <p>1990-08-01</p> <p>Compared to terrestrial and shallow-water habitats, deep-sea hydrothermal <span class="hlt">vents</span> are unique environments characterized by their local insularity, global distribution, individual ephemerality, collective geological longevity, geochemical homogeneity, and their physical and energetic isolation from the catastrophic events implicated in the extinction and speciation of terrestrial and shallow-water forms. Development of <span class="hlt">vent</span> communities has thus occurred in novel biogeographical contexts that challenge our ability to understand evolutionary processes in the deep sea. Recent field work by French, Canadian, German, Japanese and American scientists has revealed intriguing patterns in the taxonomic composition and distribution of <span class="hlt">vent</span> organisms at geographically disjunct study sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21232364','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21232364"><span id="translatedtitle">Biogeography of hydrothermal <span class="hlt">vent</span> communities along seafloor spreading centers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Van Dover, C L</p> <p>1990-08-01</p> <p>Compared to terrestrial and shallow-water habitats, deep-sea hydrothermal <span class="hlt">vents</span> are unique environments characterized by their local insularity, global distribution, individual ephemerality, collective geological longevity, geochemical homogeneity, and their physical and energetic isolation from the catastrophic events implicated in the extinction and speciation of terrestrial and shallow-water forms. Development of <span class="hlt">vent</span> communities has thus occurred in novel biogeographical contexts that challenge our ability to understand evolutionary processes in the deep sea. Recent field work by French, Canadian, German, Japanese and American scientists has revealed intriguing patterns in the taxonomic composition and distribution of <span class="hlt">vent</span> organisms at geographically disjunct study sites. PMID:21232364</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPJWC..9202062P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPJWC..9202062P"><span id="translatedtitle">Visualization of the air flow behind the automotive benchmark <span class="hlt">vent</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pech, Ondrej; Jedelsky, Jan; Caletka, Petr; Jicha, Miroslav</p> <p>2015-05-01</p> <p>Passenger comfort in cars depends on appropriate function of the cabin HVAC system. A great attention is therefore paid to the effective function of automotive <span class="hlt">vents</span> and proper formation of the flow behind the ventilation outlet. The article deals with the visualization of air flow from the automotive benchmark <span class="hlt">vent</span>. The visualization was made for two different shapes of the inlet channel connected to the benchmark <span class="hlt">vent</span>. The smoke visualization with the laser knife was used. The influence of the shape of the inlet channel to the airflow direction, its enlargement and position of air flow axis were investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3602071','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3602071"><span id="translatedtitle">Medical and surgical treatment of haemorrhoids and anal <span class="hlt">fissure</span> in Crohn’s disease: a critical appraisal</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2013-01-01</p> <p>Background The principle to avoid surgery for haemorrhoids and/or anal <span class="hlt">fissure</span> in Crohn’s disease (CD) patients is still currently valid despite advances in medical and surgical treatments. In this study we report our prospectively recorded data on medical and surgical treatment of haemorrhoids and anal <span class="hlt">fissures</span> in CD patients over a period of 8 years. Methods Clinical data of patients affected by perianal disease were routinely and prospectively inserted in a database between October 2003 and October 2011 at the Department of Surgery, Tor Vergata University Hospital, Rome. We reviewed and divided in two groups records on CD patients treated either medically or surgically according to the diagnosis of haemorrhoids or anal <span class="hlt">fissures</span>. Moreover, we compared in each group the outcome in patients with prior diagnosis of CD and in patients diagnosed with CD only after perianal main treatment. Results Eighty-six CD patients were included in the study; 45 were treated for haemorrhoids and 41 presented with anal <span class="hlt">fissure</span>. Conservative approach was initially adopted for all patients; in case of medical treatment failure, the presence of stable intestinal disease made them eligible for surgery. Fifteen patients underwent haemorrhoidectomy (open 11; closed 3; stapled 1), and two rubber band ligation. Fourteen patients required surgery for anal <span class="hlt">fissure</span> (Botox ± fissurectomy 8; LIS 6). In both groups we observed high complication rate, 41.2% for haemorrhoids and 57.1% for anal <span class="hlt">fissure</span>. Patients who underwent haemorrhoidectomy without certain diagnosis of CD had significantly higher risk of complications. Conclusions Conservative treatment of proctologic diseases in CD patients has been advocated given the high risk of complications and the evidence that spontaneous healing may also occur. From these preliminary results a role of surgery is conceivable in high selected patients, but definitve conclusions can’t be made. Further randomized trials are needed to establish the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70037208','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70037208"><span id="translatedtitle">Monitoring of land subsidence and ground <span class="hlt">fissures</span> in Xian, China 2005-2006: Mapped by sar Interferometry</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Zhao, C.Y.; Zhang, Q.; Ding, X.-L.; Lu, Zhiming; Yang, C.S.; Qi, X.M.</p> <p>2009-01-01</p> <p>The City of Xian, China, has been experiencing significant land subsidence and ground <span class="hlt">fissure</span> activities since 1960s, which have brought various severe geohazards including damages to buildings, bridges and other facilities. Monitoring of land subsidence and ground <span class="hlt">fissure</span> activities can provide useful information for assessing the extent of, and mitigating such geohazards. In order to achieve robust Synthetic Aperture Radar Interferometry (InSAR) results, six interferometric pairs of Envisat ASAR data covering 2005-2006 are collected to analyze the InSAR processing errors firstly, such as temporal and spatial decorrelation error, external DEM error, atmospheric error and unwrapping error. Then the annual subsidence rate during 2005-2006 is calculated by weighted averaging two pairs of D-InSAR results with similar time spanning. Lastly, GPS measurements are applied to calibrate the InSAR results and centimeter precision is achieved. As for the ground <span class="hlt">fissure</span> monitoring, five InSAR cross-sections are designed to demonstrate the relative subsidence difference across ground <span class="hlt">fissures</span>. In conclusion, the final InSAR subsidence map during 2005-2006 shows four large subsidence zones in Xian hi-tech zones in western, eastern and southern suburbs of Xian City, among which two subsidence cones are newly detected and two ground <span class="hlt">fissures</span> are deduced to be extended westward in Yuhuazhai subsidence cone. This study shows that the land subsidence and ground <span class="hlt">fissures</span> are highly correlated spatially and temporally and both are correlated with hi-tech zone construction in Xian during the year of 2005-2006. ?? Springer-Verlag 2008.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B23J..02P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B23J..02P"><span id="translatedtitle">Energy and Carbon Flow: Comparing ultramafic- and basalt-hosted <span class="hlt">vents</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perner, M.; Bach, W.; Seifert, R.; Strauss, H.; Laroche, J.</p> <p>2010-12-01</p> <p>In deep-sea <span class="hlt">vent</span> habitats hydrothermal fluids provide the grounds for life by supplying reduced inorganic compounds (e.g. H2, sulfide). Chemolithoautotrophs can oxidize these substrates hereby yielding energy, which can then be used to fuel autotrophic CO2 fixation. Depending on the <span class="hlt">type</span> of host rocks (and the degree of admixed ambient seawater) the availability of inorganic electron donors can vary considerably. While in ultramafic-hosted <span class="hlt">vents</span> H2 levels are high and H2-oxidizing metabolisms are thought to dominate, in basalt-hosted <span class="hlt">vents</span>, H2 is much lower and microbial sulfide oxidation is considered to prevail [1, 2]. We have investigated the effect of H2 and sulfide availability on the microbial community of distinct H2-rich and H2-poor <span class="hlt">vent</span> sites along the Mid-Atlantic Ridge. Hydrothermally influenced samples were collected from the H2-rich ultramafic-hosted Logatchev field (15°N) and the comparatively H2-poor basalt-hosted <span class="hlt">vents</span> from 5°S and 9°S. We conducted catabolic energy calculations to estimate the potential of various electron donors to function as microbial energy sources. We performed incubation experiments with hydrothermal fluids amended with H2 or sulfide and radioactively labelled bicarbonate and determined H2 and sulfide consumption and carbon incorporation rates. We constructed metagenomic libraries for sequence-based screening of genes encoding key enzymes for H2 uptake (NiFe uptake hydrogenases, group 1), sulfide oxidation (sulfide quinone oxidoreductase, sqr) and CO2 fixation pathways (RubisCOs of the Calvin cycle [CBB] and beta-subunit of the ATP citrate lyase of the reductive tricarboxylic acid cycle [rTCA]). We evaluated parts of the metagenomes from basalt-hosted sites by pyrosequencing. Based on our incubation experiments - under the conditions applied - we could not confirm that generally H2 consumption rates and biomass syntheses in fluids derived from ultramafic-hosted locations are significantly enhanced over those from basalt</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol13/pdf/CFR-2010-title40-vol13-sec63-7892.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol13/pdf/CFR-2010-title40-vol13-sec63-7892.pdf"><span id="translatedtitle">40 CFR 63.7892 - What are my inspection and monitoring requirements for process <span class="hlt">vents</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... requirements for process <span class="hlt">vents</span>? 63.7892 Section 63.7892 Protection of Environment ENVIRONMENTAL PROTECTION... Process <span class="hlt">Vents</span> § 63.7892 What are my inspection and monitoring requirements for process <span class="hlt">vents</span>? For each closed <span class="hlt">vent</span> system and control device you use to comply with § 63.7890(b), you must monitor and...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol25/pdf/CFR-2010-title40-vol25-sec265-1060.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol25/pdf/CFR-2010-title40-vol25-sec265-1060.pdf"><span id="translatedtitle">40 CFR 265.1060 - Standards: Closed-<span class="hlt">vent</span> systems and control devices.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Standards: Closed-<span class="hlt">vent</span> systems and...: Closed-<span class="hlt">vent</span> systems and control devices. (a) Owners and operators of closed-<span class="hlt">vent</span> systems and control... owner or operator of an existing facility who can not install a closed-<span class="hlt">vent</span> system and control device...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol9/pdf/CFR-2010-title40-vol9-sec63-172.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol9/pdf/CFR-2010-title40-vol9-sec63-172.pdf"><span id="translatedtitle">40 CFR 63.172 - Standards: Closed-<span class="hlt">vent</span> systems and control devices.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... olfactory indications of leaks. (2) If the vapor collection system or closed-<span class="hlt">vent</span> system is constructed of... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Standards: Closed-<span class="hlt">vent</span> systems and... Standards: Closed-<span class="hlt">vent</span> systems and control devices. (a) Owners or operators of closed-<span class="hlt">vent</span> systems...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1813553K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1813553K"><span id="translatedtitle">3D structure and formation of hydrothermal <span class="hlt">vent</span> complexes in the Møre Basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kjoberg, Sigurd; Schmiedel, Tobias; Planke, Sverre; Svensen, Henrik H.; Galland, Oliver; Jerram, Dougal A.</p> <p>2016-04-01</p> <p>The mid-Norwegian Møre margin is regarded as a <span class="hlt">type</span> example of a volcanic rifted margin, with its formation usually related to the influence of the Icelandic plume activity. The area is characterized by the presence of voluminous basaltic complexes such as extrusive lava sequences, intrusive sills and dikes, and hydrothermal <span class="hlt">vent</span> complexes within the Møre Basin. Emplacement of hydrothermal <span class="hlt">vent</span> complexes is accommodated by deformation of the host rock. The edges of igneous intrusions mobilize fluids by heat transfer into the sedimentary host rock (aureoles). Fluid expansion may lead to formation of piercing structures due to upward fluid migration. Hydrothermal <span class="hlt">vent</span> complexes induce bending of overlying strata, leading to the formation of dome structures at the paleo-surface. These dome structures are important as they indicate the accommodation created for the intrusions by deformation of the upper layers of the stratigraphy, and may form important structures in many volcanic margins. Both the morphological characteristics of the upper part and the underlying feeder-structure (conduit-zone) can be imaged and studied on 3D seismic data. Seismic data from the Tulipan prospect located in the western part of the Møre Basin have been used in this study. The investigation focusses on (1) the <span class="hlt">vent</span> complex geometries, (2) the induced surface deformation patterns, (3) the relation to the intrusions (heat source), as well as (4) the emplacement depth of the hydrothermal <span class="hlt">vent</span> complexes. We approach this by doing a detailed 3D seismic interpretation of the Tulipan seismic data cube. The complexes formed during the initial Eocene, and are believed to be a key factor behind the rapid warming event called the Paleocene-Eocene thermal maximum (PETM). The newly derived understanding of age, eruptive deposits, and formation of hydrothermal <span class="hlt">vent</span> complexes in the Møre Basin enables us to contribute to the general understanding of the igneous plumbing system in volcanic basins and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970025336','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970025336"><span id="translatedtitle"><span class="hlt">Vented</span> Tank Resupply Experiment--Flight Test Results</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chato, David J.; Martin, Timothy A.</p> <p>1997-01-01</p> <p>This paper reports the results of the <span class="hlt">Vented</span> Tank Resupply Experiment (VTRE) which was flown as a payload on STS 77. VTRE looks at the ability of vane Propellant Management Devices (PMD) to separate liquid and gas in low gravity. VTRE used two clear 0.8 cubic foot tanks one spherical and one with a short barrel section and transferred Refrigerant 113 between them as well as <span class="hlt">venting</span> it to space. Tests included retention of liquid during transfer, liquid free <span class="hlt">venting</span>, and recovery of liquid into the PMD after thruster firing. Liquid was retained successfully at the highest flow rate tested (2.73 gpm). Liquid free <span class="hlt">vents</span> were achieved for both tanks, although at a higher flow rate (0.1591 cfm) for the spherical tank than the other (0.0400 cfm). Recovery from a thruster firing which moved the liquid to the opposite end of the tank from the PMD was achieved in 30 seconds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/hi0873.photos.576217p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/hi0873.photos.576217p/"><span id="translatedtitle">DETAIL OF WEST END SLIDING DOOR AND EAVE <span class="hlt">VENTS</span> ON ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>DETAIL OF WEST END SLIDING DOOR AND EAVE <span class="hlt">VENTS</span> ON THE SOUTH SIDE - Hickam Field, Practice Bomb Loading Shed, Bomb Storage Road near the intersection of Moffet and Kamakahi Streets, Honolulu, Honolulu County, HI</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/mo1878.photos.364072p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/mo1878.photos.364072p/"><span id="translatedtitle">Looking North at Reactor Number One and Air <span class="hlt">Vent</span> on ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>Looking North at Reactor Number One and Air <span class="hlt">Vent</span> on Fourth Floor of Oxide Building - Hematite Fuel Fabrication Facility, Oxide Building & Oxide Loading Dock, 3300 State Road P, Festus, Jefferson County, MO</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title46-vol4/pdf/CFR-2012-title46-vol4-sec119-450.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title46-vol4/pdf/CFR-2012-title46-vol4-sec119-450.pdf"><span id="translatedtitle">46 CFR 119.450 - <span class="hlt">Vent</span> pipes for fuel tanks.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-10-01</p> <p>... area of 16 millimeters (0.625 inches) outer diameter (O.D.) tubing (0.9 millimeter (0.035 inch) wall... practicable from opening into any enclosed spaces. <span class="hlt">Vent</span> pipes terminating on the hull exterior must...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/ct0598.photos.317472p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/ct0598.photos.317472p/"><span id="translatedtitle">42. VIEW EAST OF PLASTIC STACK (PROBABLY PVC) WHICH <span class="hlt">VENTED</span> ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>42. VIEW EAST OF PLASTIC STACK (PROBABLY PVC) WHICH <span class="hlt">VENTED</span> FUMES FROM THE DIPPING OPERATIONS IN BUILDING 49A; BUILDING 49 IS AT THE LEFT OF THE PHOTOGRAPH - Scovill Brass Works, 59 Mill Street, Waterbury, New Haven County, CT</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/ca1499.photos.012875p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/ca1499.photos.012875p/"><span id="translatedtitle">10. VIEW OF SILO DOORS, AIR <span class="hlt">VENTS</span>, AND ESCAPE HATCH, ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>10. VIEW OF SILO DOORS, AIR <span class="hlt">VENTS</span>, AND ESCAPE HATCH, LOOKING EAST. WHITE STRUCTURES BELONG TO CURRENT OCCUPANTS Everett Weinreb, photographer, April 1988 - Los Pinetos Nike Missile Site, Santa Clara Road, Los Angeles National Forest, Sylmar, Los Angeles County, CA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/ca2228.photos.324343p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/ca2228.photos.324343p/"><span id="translatedtitle">22. STEEL ARCH SEGMENT AND <span class="hlt">VENT</span> IN OFFICE, ROOM 2351, ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>22. STEEL ARCH SEGMENT AND <span class="hlt">VENT</span> IN OFFICE, ROOM 2351, SECOND FLOOR, NORTH SIDE. - Hughes Aircraft Company, Processing & Electronics Building, 6775 Centinela Avenue, Los Angeles, Los Angeles County, CA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/hi0775.photos.367194p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/hi0775.photos.367194p/"><span id="translatedtitle">Detail of the exterior "selfclosing" sliding door with <span class="hlt">vent</span> above. ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>Detail of the exterior "self-closing" sliding door with <span class="hlt">vent</span> above. View facing northeast - U.S. Naval Base, Pearl Harbor, Paint & Oil Storehouse, Avenue D near Seventh Street intersection, Pearl City, Honolulu County, HI</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/ca2475.photos.325615p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/ca2475.photos.325615p/"><span id="translatedtitle">DETAIL OF SECOND STORY WINDOWS AND ROOF <span class="hlt">VENT</span> ON SOUTH ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>DETAIL OF SECOND STORY WINDOWS AND ROOF <span class="hlt">VENT</span> ON SOUTH END OF EAST ELEVATION; CAMERA WEST. - Mare Island Naval Shipyard, Transportation Building & Gas Station, Third Street, south side between Walnut Avenue & Cedar Avenue, Vallejo, Solano County, CA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/ca2475.photos.325614p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/ca2475.photos.325614p/"><span id="translatedtitle">DETAIL OF WINDOW AND ROOF <span class="hlt">VENT</span> AT EAST ELEVATION GABLE ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>DETAIL OF WINDOW AND ROOF <span class="hlt">VENT</span> AT EAST ELEVATION GABLE END; CAMERA FACING WEST. - Mare Island Naval Shipyard, Transportation Building & Gas Station, Third Street, south side between Walnut Avenue & Cedar Avenue, Vallejo, Solano County, CA</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/ma1517.photos.320563p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/ma1517.photos.320563p/"><span id="translatedtitle">13. DETAIL VIEW NORTHEAST OF BOILER <span class="hlt">VENTS</span> (LOWER LEFT), BREECHING ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>13. DETAIL VIEW NORTHEAST OF BOILER <span class="hlt">VENTS</span> (LOWER LEFT), BREECHING (CENTER LEFT AND CENTER), AND COAL BUNKERS (RIGHT) - Turners Falls Power & Electric Company, Hampden Station, East bank of Connecticut River, Chicopee, Hampden County, MA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/id0093.photos.059686p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/id0093.photos.059686p/"><span id="translatedtitle">7. Front of northern kiln group, looking north. <span class="hlt">Vents</span> are ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>7. Front of northern kiln group, looking north. <span class="hlt">Vents</span> are visible in all kilns, in two rows above present grade. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/ca1500.photos.012939p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/ca1500.photos.012939p/"><span id="translatedtitle">48. DETAIL VIEW OF AIR <span class="hlt">VENT</span> AT 'CATFISH' LAUNCH PAD ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>48. DETAIL VIEW OF AIR <span class="hlt">VENT</span> AT 'CATFISH' LAUNCH PAD Everett Weinreb, photographer, March 1988 - Mount Gleason Nike Missile Site, Angeles National Forest, South of Soledad Canyon, Sylmar, Los Angeles County, CA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/ca1500.photos.012938p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/ca1500.photos.012938p/"><span id="translatedtitle">47. VIEW OF AIR <span class="hlt">VENT</span> AT 'CATFISH' SILO, LOOKING SOUTHEAST. ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>47. VIEW OF AIR <span class="hlt">VENT</span> AT 'CATFISH' SILO, LOOKING SOUTHEAST. ENTRANCE TO 'BRAVO' IN BACK Everett Weinreb, photographer, March 1988 - Mount Gleason Nike Missile Site, Angeles National Forest, South of Soledad Canyon, Sylmar, Los Angeles County, CA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/va2048.photos.362277p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/va2048.photos.362277p/"><span id="translatedtitle">INTERIOR VIEW, DETAIL ORIGINAL <span class="hlt">VENTING</span> AND WINDOW, FACING NORTHWEST. ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>INTERIOR VIEW, DETAIL ORIGINAL <span class="hlt">VENTING</span> AND WINDOW, FACING NORTHWEST. - Southern Branch of the National Home for Disabled Volunteer Soldiers, Building 13, Harris Avenue at its intersection of Black Avenue and Woodfin Street, Hampton, Hampton, VA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080003809','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080003809"><span id="translatedtitle">Turbofan Engine Core Compartment <span class="hlt">Vent</span> Aerodynamic Configuration Development Methodology</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hebert, Leonard J.</p> <p>2006-01-01</p> <p>This paper presents an overview of the design methodology used in the development of the aerodynamic configuration of the nacelle core compartment <span class="hlt">vent</span> for a typical Boeing commercial airplane together with design challenges for future design efforts. Core compartment <span class="hlt">vents</span> exhaust engine subsystem flows from the space contained between the engine case and the nacelle of an airplane propulsion system. These subsystem flows typically consist of precooler, oil cooler, turbine case cooling, compartment cooling and nacelle leakage air. The design of core compartment <span class="hlt">vents</span> is challenging due to stringent design requirements, mass flow sensitivity of the system to small changes in <span class="hlt">vent</span> exit pressure ratio, and the need to maximize overall exhaust system performance at cruise conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/ca3272.photos.206903p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/ca3272.photos.206903p/"><span id="translatedtitle">View of building 11070 showing <span class="hlt">vents</span> and forced air system ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>View of building 11070 showing <span class="hlt">vents</span> and forced air system on east side, looking southwest. - Naval Ordnance Test Station Inyokern, China Lake Pilot Plant, Maintenance Shop, C Street, China Lake, Kern County, CA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7008056','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7008056"><span id="translatedtitle">Evaluation of soil-<span class="hlt">venting</span> application. Ground-water issue</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>DiGiulio, D.C.</p> <p>1992-04-01</p> <p>The Regional Superfund Ground-Water Forum is a group of scientists, representing EPA's Regional Superfund Offices, organized to exchange up-to-date information related to ground-water remediation at Superfund sites. One of the major issues of concern to the Forum is the transport and fate of contaminants in soil and ground water as related to subsurface remediation. The ability of soil <span class="hlt">venting</span> to inexpensively remove large amounts of volatile organic compounds (VOCs) from contaminated soils is well established. However, the time required using <span class="hlt">venting</span> to remediate soils to low contaminant levels often required by state and federal regulators has not been adequately investigated. Discussion is presented to aid in evaluating the feasibility of <span class="hlt">venting</span> application. Methods to optimize <span class="hlt">venting</span> application are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol20/pdf/CFR-2010-title40-vol20-sec87-11.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol20/pdf/CFR-2010-title40-vol20-sec87-11.pdf"><span id="translatedtitle">40 CFR 87.11 - Standard for fuel <span class="hlt">venting</span> emissions.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... fuel <span class="hlt">venting</span> emissions shall be discharged into the atmosphere from any new or in-use aircraft gas... discharge to the atmosphere of fuel drained from fuel nozzle manifolds after engines are shut down and...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol21/pdf/CFR-2013-title40-vol21-sec87-11.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol21/pdf/CFR-2013-title40-vol21-sec87-11.pdf"><span id="translatedtitle">40 CFR 87.11 - Standard for fuel <span class="hlt">venting</span> emissions.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... fuel <span class="hlt">venting</span> emissions shall be discharged into the atmosphere from any new or in-use aircraft gas... discharge to the atmosphere of fuel drained from fuel nozzle manifolds after engines are shut down and...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol20/pdf/CFR-2014-title40-vol20-sec87-11.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol20/pdf/CFR-2014-title40-vol20-sec87-11.pdf"><span id="translatedtitle">40 CFR 87.11 - Standard for fuel <span class="hlt">venting</span> emissions.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... <span class="hlt">venting</span> emissions shall be discharged into the atmosphere from any new or in-use aircraft gas turbine... the atmosphere of fuel drained from fuel nozzle manifolds after engines are shut down and does...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title14-vol1/pdf/CFR-2014-title14-vol1-sec34-11.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title14-vol1/pdf/CFR-2014-title14-vol1-sec34-11.pdf"><span id="translatedtitle">14 CFR 34.11 - Standard for fuel <span class="hlt">venting</span> emissions.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-01-01</p> <p>... fuel <span class="hlt">venting</span> emissions shall be discharged into the atmosphere from any new or in-use aircraft gas... discharge to the atmosphere of fuel drained from fuel nozzle manifolds after engines are shut down and...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040065937&hterms=Hydrothermal+vents&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D%2528Hydrothermal%2Bvents%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040065937&hterms=Hydrothermal+vents&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D%2528Hydrothermal%2Bvents%2529"><span id="translatedtitle">Optical Detection of Organic Chemical Biosignatures at Hydrothermal <span class="hlt">Vents</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Conrad, P. G.; Lane, A. L.; Bhartia, R.; Hug, W. H.</p> <p>2004-01-01</p> <p>We have developed a non-contact, optical life detection instrument that can detect organic chemical biosignatures in a number of different environments, including dry land, shallow aqueous, deep marine or in ice. Hence, the instrument is appropriate as a biosignature survey tool both for Mars exploration or in situ experiments in an ice-covered ocean such as one might wish to explore on Europa. Here, we report the results we obtained on an expedition aboard the Russian oceanographic vessel Akademik Mstislav Keldysh to hydrothermal <span class="hlt">vent</span> sites in the Pacific Ocean using our life detection instrument MCDUVE, a multichannel, deep ultraviolet excitation fluorescence detector. MCDUVE detected organic material distribution on rocks near the <span class="hlt">vent</span>, as well as direct detection of organisms, both microbial and microscopic. We also were able to detect organic material issuing directly from <span class="hlt">vent</span> chimneys, measure the organic signature of the water column as we ascended, and passively observe the emission of light directly from some <span class="hlt">vents</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=291906','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=291906"><span id="translatedtitle">Three QTLs conferring resistance to kernel <span class="hlt">fissuring</span> in rice (Oryza sativa L.) identified by selective genotyping in two tropical japonica populations</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Kernel <span class="hlt">fissures</span> caused by pre- or post-harvest stresses are the leading cause of breakage among milled rice, causing economic losses for producers, millers, and processors. Being an environmentally sensitive trait, it is difficult to reliably select for rice <span class="hlt">fissure</span> resistance among breeding progen...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.P41B3898P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.P41B3898P"><span id="translatedtitle">The Implications of Flank <span class="hlt">Vents</span> on Olympus Mons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peters, S.; Christensen, P. R.</p> <p>2014-12-01</p> <p>Flank <span class="hlt">vents</span> are a common feature on polygenetic volcanoes. They indicate that magma has propagated away from the main conduit and/or magma chamber. Flank <span class="hlt">vents</span> and flank eruptions have been documented and studied on a number of terrestrial volcanoes and to a lesser degree on Mars. The distribution of volcanic <span class="hlt">vents</span> about a central caldera can provide information on radial dikes and tectonic stresses acting on the volcano, and can constrain models involving the emplacement and flexure of the edifice (e.g. Nakamura, 1976; McGovern and Solomon, 1993). In the absence of spectral data (due to optically thick dust cover) and in situ observations, morphology is a powerful tool for ascertaining the eruptive and tectonic history of Olympus Mons. Approximately 190 high-resolution CTX (Context Camera) images covering Olympus Mons have been mosaicked together. The analysis of a CTX mosaic reveals Mars's largest shield volcano in stunning detail and allows for a thorough analysis of the targeted features. Preliminary results show numerous flank <span class="hlt">vents</span> some of which produce leveed channels on the slopes of Olympus Mons. Some <span class="hlt">vents</span> display varying morphologies, suggesting that the style of volcanism has evolved over time. Flank <span class="hlt">vents</span> are observed to occur over a range of elevations, although a paucity of <span class="hlt">vents</span> is observed on the lower flank. Analyses are ongoing and include mapping the spatial and elevation distribution of flank <span class="hlt">vents</span> on the shield. Once mapped, the distribution of flank <span class="hlt">vents</span> will define the orientation of tectonic stresses acting on Olympus Mons and help determine whether they are influenced by underlying topography, regional scale processes or a combination of both. In addition, these <span class="hlt">vents</span> act as a window into the subsurface which can help characterize dike emplacement within the shield. Furthermore, the morphology of flank <span class="hlt">vents</span> will provide information on the evolution of their eruptive styles. All of this information is crucial to help understand the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1714688G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1714688G"><span id="translatedtitle">Morphology and dynamics of explosive <span class="hlt">vents</span> through cohesive rock formations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Galland, Olivier; Gisler, Galen R.; Haug, Øystein T.</p> <p>2015-04-01</p> <p>Shallow explosive volcanic processes, such as kimberlite volcanism, phreatomagmatic and phreatic activity, produce volcanic <span class="hlt">vents</span> exhibiting a wide variety of morphologies, including vertical pipes and V-shaped <span class="hlt">vents</span>. In this study we report on experimental and numerical models designed to capture a range of <span class="hlt">vent</span> morphologies in an eruptive system (Galland et al., 2014). Using dimensional analysis, we identified key governing dimensionless parameters, in particular the gravitational stress-to-fluid pressure ratio (Π2=P/rho.g.h), and the fluid pressure-to-host rock strength ratio (Π3=P/C). We used combined experimental and numerical models to test the effects of these parameters. The experiments were used to test the effect of Π2 on <span class="hlt">vent</span> morphology and dynamics. A phase diagram demonstrates a separation between two distinct morphologies, with vertical structures occurring at high values of Π2, and diagonal ones at low values of Π2. The numerical simulations were used to test the effect of Π3 on <span class="hlt">vent</span> morphology and dynamics. In the numerical models we see three distinct morphologies: vertical pipes are produced at high values of Π3, diagonal pipes at low values of Π3, while horizontal sills are produced for intermediate values of Π3. Our results show that vertical pipes form by plasticity-dominated yielding for high-energy systems (high Π2 and Π3), whereas diagonal and horizontal <span class="hlt">vents</span> dominantly form by fracturing for lower-energy systems (low Π2 and Π3). Although our models are 2-dimensionnal, they suggest that circular pipes result from plastic yielding of the host rock in a high-energy regime, whereas V-shaped volcanic <span class="hlt">vents</span> result from fracturing of the host rock in lower-energy systems. Galland, O., Gisler, G.R., Haug, Ø.T., 2014. Morphology and dynamics of explosive <span class="hlt">vents</span> through cohesive rock formations. J. Geophys. Res. 119, 10.1002/2014JB011050.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3250503','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3250503"><span id="translatedtitle">Antarctic Marine Biodiversity and Deep-Sea Hydrothermal <span class="hlt">Vents</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chown, Steven L.</p> <p>2012-01-01</p> <p>The diversity of many marine benthic groups is unlike that of most other taxa. Rather than declining from the tropics to the poles, much of the benthos shows high diversity in the Southern Ocean. Moreover, many species are unique to the Antarctic region. Recent work has shown that this is also true of the communities of Antarctic deep-sea hydrothermal <span class="hlt">vents</span>. <span class="hlt">Vent</span> ecosystems have been documented from many sites across the globe, associated with the thermally and chemically variable habitats found around these, typically high temperature, streams that are rich in reduced compounds and polymetallic sulphides. The animal communities of the East Scotia Ridge <span class="hlt">vent</span> ecosystems are very different to those elsewhere, though the microbiota, which form the basis of <span class="hlt">vent</span> food webs, show less differentiation. Much of the biological significance of deep-sea hydrothermal <span class="hlt">vents</span> lies in their biodiversity, the diverse biochemistry of their bacteria, the remarkable symbioses among many of the marine animals and these bacteria, and the prospects that investigations of these systems hold for understanding the conditions that may have led to the first appearance of life. The discovery of diverse and unusual Antarctic hydrothermal <span class="hlt">vent</span> ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic <span class="hlt">vents</span> south of 60°S benefit from automatic conservation under the Convention on the Conservation of Antarctic Marine Living Resources and the Antarctic Treaty. Other deep-sea hydrothermal <span class="hlt">vents</span> located in international waters are not protected and may be threatened by growing interests in deep-sea mining. PMID:22235192</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950057135&hterms=Hydrothermal+vents&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528Hydrothermal%2Bvents%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950057135&hterms=Hydrothermal+vents&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528Hydrothermal%2Bvents%2529"><span id="translatedtitle">The stability of amino acids at submarine hydrothermal <span class="hlt">vent</span> temperatures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bada, Jeffrey L.; Miller, Stanley L.; Zhao, Meixun</p> <p>1995-01-01</p> <p>It has been postulated that amino acid stability at hydrothermal <span class="hlt">vent</span> temperatures is controlled by a metastable thermodynamic equilibrium rather than by kinetics. Experiments reported here demonstrate that the amino acids are irreversibly destroyed by heating at 240 C and that quasi-equilibrium calculations give misleading descriptions of the experimental observations. Equilibrium thermodynamic calculations are not applicable to organic compounds under high-temperature submarine <span class="hlt">vent</span> conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title46-vol5/pdf/CFR-2010-title46-vol5-sec153-351.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title46-vol5/pdf/CFR-2010-title46-vol5-sec153-351.pdf"><span id="translatedtitle">46 CFR 153.351 - Location of 4m <span class="hlt">vent</span> discharges.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-10-01</p> <p>... 46 Shipping 5 2010-10-01 2010-10-01 false Location of 4m <span class="hlt">vent</span> discharges. 153.351 Section 153.351... <span class="hlt">Venting</span> Systems § 153.351 Location of 4m <span class="hlt">vent</span> discharges. Except as prescribed in § 153.353, a 4m <span class="hlt">venting</span>...) any walkway that is within a 4m (approx. 13.1 ft) horizontal radius from the <span class="hlt">vent</span> discharge. (b)...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994AnPh...19..459S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994AnPh...19..459S"><span id="translatedtitle">Des <span class="hlt">Vents</span> et des Jets Astrophysiques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sauty, C.</p> <p></p> <p> well expected result from the theory. Although, collimation may be conical, paraboloidal or cylindrical (Part 4), cylindrical collimation is the more likely to occur. The shape of outflows may then be used as a tool to predict physical conditions on the flows or on their source. L'éjection continue de plasma autour d'objets massifs est un phénomène largement répandu en astrophysique, que ce soit sous la forme du <span class="hlt">vent</span> solaire, de <span class="hlt">vents</span> stellaires, de jets d'étoiles en formation, de jets stellaires autour d'objets compacts ou de jets extra-galactiques. Cette zoologie diversifiée fait pourtant l'objet d'un commun effort de modélisation. Le but de cette revue est d'abord de présenter qualitativement le développement, depuis leur origine, des diverses théories de <span class="hlt">vents</span> (Partie 1) et l'inter disciplinarité dans ce domaine. Il s'agit d'une énumération, plus ou moins exhaustive, des idées proposées pour expliquer l'accélération et la morphologie des <span class="hlt">vents</span> et des jets, accompagnée d'une présentation sommaire des aspects observationnels. Cette partie s'abstient de tout aspect faisant appel au formalisme mathématique. Ces écoulements peuvent être décrits, au moins partiellement, en résolvant les équations magnétohydrodynamiques, axisymétriques et stationnaires. Ce formalisme, à la base de la plupart des théories, est exposé dans la Partie 2. Il permet d'introduire quantitativement les intégrales premières qu'un tel système possède. Ces dernières sont amenées à jouer un rôle important dans la compréhension des phénomènes d'accélération ou de collimation, en particulier le taux de perte de masse, le taux de perte de moment angulaire ou l'énergie du rotateur magnétique. La difficulté de modélisation réside dans l'existence de points critiques, propres aux équations non linéaires, qu'il faut franchir. La nature physique et la localisation de ces points critiques fait l'objet d'un débat important car ils sont la clef de voute de la r</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3779335','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3779335"><span id="translatedtitle">Cryptic species of Archinome (Annelida: Amphinomida) from <span class="hlt">vents</span> and seeps</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Borda, Elizabeth; Kudenov, Jerry D.; Chevaldonné, Pierre; Blake, James A.; Desbruyères, Daniel; Fabri, Marie-Claire; Hourdez, Stéphane; Pleijel, Fredrik; Shank, Timothy M.; Wilson, Nerida G.; Schulze, Anja; Rouse, Greg W.</p> <p>2013-01-01</p> <p>Since its description from the Galapagos Rift in the mid-1980s, Archinome rosacea has been recorded at hydrothermal <span class="hlt">vents</span> in the Pacific, Atlantic and Indian Oceans. Only recently was a second species described from the Pacific Antarctic Ridge. We inferred the identities and evolutionary relationships of Archinome representatives sampled from across the hydrothermal <span class="hlt">vent</span> range of the genus, which is now extended to cold methane seeps. Species delimitation using mitochondrial cytochrome c oxidase subunit I (COI) recovered up to six lineages, whereas concatenated datasets (COI, 16S, 28S and ITS1) supported only four or five of these as clades. Morphological approaches alone were inconclusive to verify the identities of species owing to the lack of discrete diagnostic characters. We recognize five Archinome species, with three that are new to science. The new species, designated based on molecular evidence alone, include: Archinome levinae n. sp., which occurs at both <span class="hlt">vents</span> and seeps in the east Pacific, Archinome tethyana n. sp., which inhabits Atlantic <span class="hlt">vents</span> and Archinome jasoni n. sp., also present in the Atlantic, and whose distribution extends to the Indian and southwest Pacific Oceans. Biogeographic connections between <span class="hlt">vents</span> and seeps are highlighted, as are potential evolutionary links among populations from <span class="hlt">vent</span> fields located in the east Pacific and Atlantic Oceans, and Atlantic and Indian Oceans; the latter presented for the first time. PMID:24026823</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21833083','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21833083"><span id="translatedtitle">Hydrogen is an energy source for hydrothermal <span class="hlt">vent</span> symbioses.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Petersen, Jillian M; Zielinski, Frank U; Pape, Thomas; Seifert, Richard; Moraru, Cristina; Amann, Rudolf; Hourdez, Stephane; Girguis, Peter R; Wankel, Scott D; Barbe, Valerie; Pelletier, Eric; Fink, Dennis; Borowski, Christian; Bach, Wolfgang; Dubilier, Nicole</p> <p>2011-08-11</p> <p>The discovery of deep-sea hydrothermal <span class="hlt">vents</span> in 1977 revolutionized our understanding of the energy sources that fuel primary productivity on Earth. Hydrothermal <span class="hlt">vent</span> ecosystems are dominated by animals that live in symbiosis with chemosynthetic bacteria. So far, only two energy sources have been shown to power chemosynthetic symbioses: reduced sulphur compounds and methane. Using metagenome sequencing, single-gene fluorescence in situ hybridization, immunohistochemistry, shipboard incubations and in situ mass spectrometry, we show here that the symbionts of the hydrothermal <span class="hlt">vent</span> mussel Bathymodiolus from the Mid-Atlantic Ridge use hydrogen to power primary production. In addition, we show that the symbionts of Bathymodiolus mussels from Pacific <span class="hlt">vents</span> have hupL, the key gene for hydrogen oxidation. Furthermore, the symbionts of other <span class="hlt">vent</span> animals such as the tubeworm Riftia pachyptila and the shrimp Rimicaris exoculata also have hupL. We propose that the ability to use hydrogen as an energy source is widespread in hydrothermal <span class="hlt">vent</span> symbioses, particularly at sites where hydrogen is abundant. PMID:21833083</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21833083','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21833083"><span id="translatedtitle">Hydrogen is an energy source for hydrothermal <span class="hlt">vent</span> symbioses.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Petersen, Jillian M; Zielinski, Frank U; Pape, Thomas; Seifert, Richard; Moraru, Cristina; Amann, Rudolf; Hourdez, Stephane; Girguis, Peter R; Wankel, Scott D; Barbe, Valerie; Pelletier, Eric; Fink, Dennis; Borowski, Christian; Bach, Wolfgang; Dubilier, Nicole</p> <p>2011-08-10</p> <p>The discovery of deep-sea hydrothermal <span class="hlt">vents</span> in 1977 revolutionized our understanding of the energy sources that fuel primary productivity on Earth. Hydrothermal <span class="hlt">vent</span> ecosystems are dominated by animals that live in symbiosis with chemosynthetic bacteria. So far, only two energy sources have been shown to power chemosynthetic symbioses: reduced sulphur compounds and methane. Using metagenome sequencing, single-gene fluorescence in situ hybridization, immunohistochemistry, shipboard incubations and in situ mass spectrometry, we show here that the symbionts of the hydrothermal <span class="hlt">vent</span> mussel Bathymodiolus from the Mid-Atlantic Ridge use hydrogen to power primary production. In addition, we show that the symbionts of Bathymodiolus mussels from Pacific <span class="hlt">vents</span> have hupL, the key gene for hydrogen oxidation. Furthermore, the symbionts of other <span class="hlt">vent</span> animals such as the tubeworm Riftia pachyptila and the shrimp Rimicaris exoculata also have hupL. We propose that the ability to use hydrogen as an energy source is widespread in hydrothermal <span class="hlt">vent</span> symbioses, particularly at sites where hydrogen is abundant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24026823','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24026823"><span id="translatedtitle">Cryptic species of Archinome (Annelida: Amphinomida) from <span class="hlt">vents</span> and seeps.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Borda, Elizabeth; Kudenov, Jerry D; Chevaldonné, Pierre; Blake, James A; Desbruyères, Daniel; Fabri, Marie-Claire; Hourdez, Stéphane; Pleijel, Fredrik; Shank, Timothy M; Wilson, Nerida G; Schulze, Anja; Rouse, Greg W</p> <p>2013-11-01</p> <p>Since its description from the Galapagos Rift in the mid-1980s, Archinome rosacea has been recorded at hydrothermal <span class="hlt">vents</span> in the Pacific, Atlantic and Indian Oceans. Only recently was a second species described from the Pacific Antarctic Ridge. We inferred the identities and evolutionary relationships of Archinome representatives sampled from across the hydrothermal <span class="hlt">vent</span> range of the genus, which is now extended to cold methane seeps. Species delimitation using mitochondrial cytochrome c oxidase subunit I (COI) recovered up to six lineages, whereas concatenated datasets (COI, 16S, 28S and ITS1) supported only four or five of these as clades. Morphological approaches alone were inconclusive to verify the identities of species owing to the lack of discrete diagnostic characters. We recognize five Archinome species, with three that are new to science. The new species, designated based on molecular evidence alone, include: Archinome levinae n. sp., which occurs at both <span class="hlt">vents</span> and seeps in the east Pacific, Archinome tethyana n. sp., which inhabits Atlantic <span class="hlt">vents</span> and Archinome jasoni n. sp., also present in the Atlantic, and whose distribution extends to the Indian and southwest Pacific Oceans. Biogeographic connections between <span class="hlt">vents</span> and seeps are highlighted, as are potential evolutionary links among populations from <span class="hlt">vent</span> fields located in the east Pacific and Atlantic Oceans, and Atlantic and Indian Oceans; the latter presented for the first time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/884807','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/884807"><span id="translatedtitle">A Feasibility Study of H{sub 2}S Abatement by Incineration of Noncondensable Gases in <span class="hlt">Vented</span> Steam Flow from Davies-State 5206-1 Geothermal Steam Well, Geysers Geothermal Steam Field, Lake County, California</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>2006-08-25</p> <p>Determine feasibility of using an incineration-<span class="hlt">type</span> device to accomplish the required reduction in <span class="hlt">vent</span> steam H{sub 2}S content to meet ICAPCO rules. This approach is to be the only method considered in this feasibility study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.V44A..01B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.V44A..01B"><span id="translatedtitle">Overview of <span class="hlt">Vent</span> Fluid Chemistry From the Marianas Volcanic Arc</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Butterfield, D. A.; Roe, K. K.; Bolton, S. A.; Baross, J. A.; Lupton, J. E.; Lilley, M. D.; Embley, R. W.; Chadwick, W. W.; Resing, J. A.</p> <p>2004-12-01</p> <p>In March and April 2004, a research expedition on the R.V.T.G. Thompason with the ROV ROPOS investigated and sampled hydrothermal systems on six submarine volcanoes of the Marianas volcanic arc between 14.3 and 21.5 degrees N. In this two-year project sponsored by NOAA Ocean Exploration, dive targets were selected based on bathymetric and hydrothermal plume mapping conducted in 2003. Hydrothermal plume intesity and chemistry was used with success to target and sample a remarkable variety of volcanic and hydrothermal features. At NW Rota-1 submarine volcano, there is clear evidence of ongoing eruptive activity producing clouds of particulate and molten sulfur as well as mm to cm-size glassy volcanic ejecta. Fluids (34 deg C) sampled directly from an eruptive pit crater has pH of 2.0, with a high content of particulated sulfur, excess sulfate relative to seawater, and very low H2s content. Fluids percolating through volcaniclastic sand adjacent to the pit reached 100 deg C and had higher silica, slightly higher pH, and millimolar levels of H2s. The chemistry of both <span class="hlt">types</span> of fluids is indicative of input of volcanic SO2 and disproportionation into sulfate and H2s (in volcaniclastic sands) and elemental sulfur (in the pit crater). Molten sulfur droplets indicate a high-temperature source at the base of the pit crater that rapidly mixes with seawater, while fluids <span class="hlt">venting</span> through the sand remain hotter and react with volcanic glass. DNA was collected by in-situ filtration and both archaea and bacteria were amplified by PCR. Bacterial clone libraries were dominated by epsilon Proteobacteria with a high degree of relatedness to microaerophilic sulfur-, sulfide-, and hydrogen oxidizers belonging to the genera Sulfurimonas and Calderomonas. At East Diamante submarine volcano, several hydrothermal areas were found on resurgent domes within the large caldera. One of these sites hosted the only high-temperature deposits. The high volatile content of the volcanic arc</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS13B1731M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS13B1731M"><span id="translatedtitle">How Disturbance Influences Community Composition at Hydrothermal <span class="hlt">Vents</span>: a Theoretical Model of Macrofaunal Coexistence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miller, A. D.; Hsing, P.; Roxburgh, S. H.; Shea, K.; Fisher, C. R.</p> <p>2012-12-01</p> <p>Biological communities at spreading centers experience a continuum of disturbance regimes, with fast spreading ridges characterized by relatively frequent tectonic and magmatic events, and slow spreading ridges displaying more stable environmental conditions. We develop a theoretical model to show how disturbance (or lack thereof) can influence the composition of biological communities at hydrothermal <span class="hlt">vents</span>. Our model assumptions are based on empirical data, which show that macrofaunal species of interest (Riftia pachyptila, Bathymodiolus thermophilus, Calyptogena magnifica) establish in distinct microhabitats, based on availability of <span class="hlt">vent</span> fluids that nourish endosymbiotic chemoautotrophs. We focus on how these establishment strategies interact with species fecundity, and with disturbance frequency and intensity, to determine what <span class="hlt">types</span> of strategies can coexist in the system. We find that species must adopt sufficiently different fecundity-establishment strategies to coexist in the community, though strict tradeoffs between fecundity and establishment ability are not required. Additionally, we describe how the strategies that lead to coexistence depend on habitat availability and disturbance regime. Though other coexistence mechanisms may also play a role, our findings suggest why communities within a single biogeographic province may vary with spreading rate (as from N to S along the East Pacific Rise), and what strategies will allow coexistence under different disturbance regimes. Understanding how changes to disturbance regimes influence community composition is very important, as commercial mining interests are rapidly developing plans to exploit the rich mineral resources associated with hydrothermal <span class="hlt">vents</span> and their activities will change the disturbance regime.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23630523','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23630523"><span id="translatedtitle">Biogeography of Persephonella in deep-sea hydrothermal <span class="hlt">vents</span> of the Western Pacific.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mino, Sayaka; Makita, Hiroko; Toki, Tomohiro; Miyazaki, Junichi; Kato, Shingo; Watanabe, Hiromi; Imachi, Hiroyuki; Watsuji, Tomo-O; Nunoura, Takuro; Kojima, Shigeaki; Sawabe, Tomoo; Takai, Ken; Nakagawa, Satoshi</p> <p>2013-01-01</p> <p>Deep-sea hydrothermal <span class="hlt">vent</span> fields are areas on the seafloor with high biological productivity fueled by microbial chemosynthesis. Members of the Aquificales genus Persephonella are obligately chemosynthetic bacteria, and appear to be key players in carbon, sulfur, and nitrogen cycles in high temperature habitats at deep-sea <span class="hlt">vents</span>. Although this group of bacteria has cosmopolitan distribution in deep-sea hydrothermal ecosystem around the world, little is known about their population structure such as intraspecific genomic diversity, distribution pattern, and phenotypic diversity. We developed the multi-locus sequence analysis (MLSA) scheme for their genomic characterization. Sequence variation was determined in five housekeeping genes and one functional gene of 36 Persephonella hydrogeniphila strains originated from the Okinawa Trough and the South Mariana Trough (SNT). Although the strains share >98.7% similarities in 16S rRNA gene sequences, MLSA revealed 35 different sequence <span class="hlt">types</span> (ST), indicating their extensive genomic diversity. A phylogenetic tree inferred from all concatenated gene sequences revealed the clustering of isolates according to the geographic origin. In addition, the phenotypic clustering pattern inferred from whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis can be correlated to their MLSA clustering pattern. This study represents the first MLSA combined with phenotypic analysis indicative of allopatric speciation of deep-sea hydrothermal <span class="hlt">vent</span> bacteria.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4677816','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4677816"><span id="translatedtitle">Seagrass biofilm communities at a naturally CO2-rich <span class="hlt">vent</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hassenrück, Christiane; Hofmann, Laurie C; Bischof, Kai; Ramette, Alban</p> <p>2015-01-01</p> <p>Seagrass meadows are a crucial component of tropical marine reef ecosystems. Seagrass plants are colonized by a multitude of epiphytic organisms that contribute to broadening the ecological role of seagrasses. To better understand how environmental changes like ocean acidification might affect epiphytic assemblages, the microbial community composition of the epiphytic biofilm of Enhalus acroides was investigated at a natural CO2 <span class="hlt">vent</span> in Papua New Guinea using molecular fingerprinting and next-generation sequencing of 16S and 18S rRNA genes. Both bacterial and eukaryotic epiphytes formed distinct communities at the CO2-impacted site compared with the control site. This site-related CO2 effect was also visible in the succession pattern of microbial epiphytes. We further found an increased relative sequence abundance of bacterial <span class="hlt">types</span> associated with coral diseases at the CO2-impacted site (Fusobacteria, Thalassomonas), whereas eukaryotes such as certain crustose coralline algae commonly related to healthy reefs were less diverse. These trends in the epiphytic community of E. acroides suggest a potential role of seagrasses as vectors of coral pathogens and may support previous predictions of a decrease in reef health and prevalence of diseases under future ocean acidification scenarios. PMID:25727314</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25727314','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25727314"><span id="translatedtitle">Seagrass biofilm communities at a naturally CO2 -rich <span class="hlt">vent</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hassenrück, Christiane; Hofmann, Laurie C; Bischof, Kai; Ramette, Alban</p> <p>2015-06-01</p> <p>Seagrass meadows are a crucial component of tropical marine reef ecosystems. Seagrass plants are colonized by a multitude of epiphytic organisms that contribute to broadening the ecological role of seagrasses. To better understand how environmental changes like ocean acidification might affect epiphytic assemblages, the microbial community composition of the epiphytic biofilm of Enhalus acroides was investigated at a natural CO2 <span class="hlt">vent</span> in Papua New Guinea using molecular fingerprinting and next-generation sequencing of 16S and 18S rRNA genes. Both bacterial and eukaryotic epiphytes formed distinct communities at the CO2 -impacted site compared with the control site. This site-related CO2 effect was also visible in the succession pattern of microbial epiphytes. We further found an increased relative sequence abundance of bacterial <span class="hlt">types</span> associated with coral diseases at the CO2 -impacted site (Fusobacteria, Thalassomonas), whereas eukaryotes such as certain crustose coralline algae commonly related to healthy reefs were less diverse. These trends in the epiphytic community of E. acroides suggest a potential role of seagrasses as vectors of coral pathogens and may support previous predictions of a decrease in reef health and prevalence of diseases under future ocean acidification scenarios. PMID:25727314</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/567228','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/567228"><span id="translatedtitle">Validation testing of radioactive waste drum filter <span class="hlt">vents</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weber, L.D.; Rahimi, R.S.; Edling, D.</p> <p>1997-08-01</p> <p>The minimum requirements for Drum Filter <span class="hlt">Vents</span> (DFVs) can be met by demonstrating conformance with the Waste Isolation Pilot Plant (WIPP) Trupact II Safety Assessment Report (SAR), and conformance with U.S. Federal shipping regulations 49 CFR 178.350, DOT Spec 7A, for <span class="hlt">Type</span> A packages. These together address a number of safety related performance parameters such as hydrogen diffusivity, flow related pressure drop, filtration efficiency and, separately, mechanical stability and the ability to prevent liquid water in-leakage. In order to make all metal DFV technology (including metallic filter medium) available to DOE sites, Pall launched a product development program to validate an all metal design to meet these requirements. Numerous problems experienced by DOE sites in the past came to light during this development program. They led us to explore enhancements to DFV design and performance testing addressing these difficulties and concerns. The result is a patented all metal DFV certified to all applicable regulatory requirements, which for the first time solves operational and health safety problems reported by DOE site personnel but not addressed by previous DFV`s. The new technology facilitates operations (such as manual, automated and semi-automated drum handling/redrumming), sampling, on-site storage, and shipping. At the same time, it upgrades filtration efficiency in configurations documented to maintain filter efficiency following mechanical stress. 2 refs., 2 figs., 10 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25727314','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25727314"><span id="translatedtitle">Seagrass biofilm communities at a naturally CO2 -rich <span class="hlt">vent</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hassenrück, Christiane; Hofmann, Laurie C; Bischof, Kai; Ramette, Alban</p> <p>2015-06-01</p> <p>Seagrass meadows are a crucial component of tropical marine reef ecosystems. Seagrass plants are colonized by a multitude of epiphytic organisms that contribute to broadening the ecological role of seagrasses. To better understand how environmental changes like ocean acidification might affect epiphytic assemblages, the microbial community composition of the epiphytic biofilm of Enhalus acroides was investigated at a natural CO2 <span class="hlt">vent</span> in Papua New Guinea using molecular fingerprinting and next-generation sequencing of 16S and 18S rRNA genes. Both bacterial and eukaryotic epiphytes formed distinct communities at the CO2 -impacted site compared with the control site. This site-related CO2 effect was also visible in the succession pattern of microbial epiphytes. We further found an increased relative sequence abundance of bacterial <span class="hlt">types</span> associated with coral diseases at the CO2 -impacted site (Fusobacteria, Thalassomonas), whereas eukaryotes such as certain crustose coralline algae commonly related to healthy reefs were less diverse. These trends in the epiphytic community of E. acroides suggest a potential role of seagrasses as vectors of coral pathogens and may support previous predictions of a decrease in reef health and prevalence of diseases under future ocean acidification scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ChJOL..34.1238Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ChJOL..34.1238Z"><span id="translatedtitle">Effect of an escape <span class="hlt">vent</span> in accordion-shaped traps on the catch and size of Asian paddle crabs Charybdis japonica in an artificial reef area</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Peng; Li, Chao; Li, Wentao; Zhang, Xiumei</p> <p>2016-11-01</p> <p>Accordion-shaped traps are widely used in China to catch the Asian paddle crab Charybdis japonica but traps of conventional design often catch juvenile crabs. A new <span class="hlt">type</span> of accordion-shaped trap with an escape <span class="hlt">vent</span> (L×W=4.3 cm×3.0 cm) was designed and a comparative study between the newly designed and conventional traps was performed in the artificial reef area of Zhuwang, Laizhou Bay, China from June to August 2012. The mean catch per unit effort (CPUE) of undersized crabs was significantly lower in the <span class="hlt">vented</span> traps than in the conventional traps (paired t -test, n=30, P<0.001), while the CPUE of marketable crabs was significantly higher in the <span class="hlt">vented</span> traps (paired t-test, n=30, P<0.001). The mean size of crabs (carapace length) caught in the <span class="hlt">vented</span> traps was significantly larger than in conventional traps (paired t-test, n=29, P<0.001). The ratio of undersized crabs was 35.05±2.57% in conventional traps and 12.53±0.69% in <span class="hlt">vented</span> traps (significantly lower, paired t-test, n=29, P<0.001). Therefore, a 4.3 cm×3.0 cm escape <span class="hlt">vent</span> was considered appropriate for C. japonica fishing in the artificial reef area. This finding will assist the development of more sustainable and efficient crab fishing methods using accordion-shaped traps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ChJOL.tmp...30Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ChJOL.tmp...30Z&link_type=ABSTRACT"><span id="translatedtitle">Effect of an escape <span class="hlt">vent</span> in accordion-shaped traps on the catch and size of Asian paddle crabs Charybdis japonica in an artificial reef area</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Peng; Li, Chao; Li, Wentao; Zhang, Xiumei</p> <p>2016-02-01</p> <p>Accordion-shaped traps are widely used in China to catch the Asian paddle crab Charybdis japonica but traps of conventional design often catch juvenile crabs. A new <span class="hlt">type</span> of accordion-shaped trap with an escape <span class="hlt">vent</span> (L×W=4.3 cm×3.0 cm) was designed and a comparative study between the newly designed and conventional traps was performed in the artificial reef area of Zhuwang, Laizhou Bay, China from June to August 2012. The mean catch per unit effort (CPUE) of undersized crabs was significantly lower in the <span class="hlt">vented</span> traps than in the conventional traps (paired t -test, n=30, P<0.001), while the CPUE of marketable crabs was significantly higher in the <span class="hlt">vented</span> traps (paired t-test, n=30, P<0.001). The mean size of crabs (carapace length) caught in the <span class="hlt">vented</span> traps was significantly larger than in conventional traps (paired t-test, n=29, P<0.001). The ratio of undersized crabs was 35.05±2.57% in conventional traps and 12.53±0.69% in <span class="hlt">vented</span> traps (significantly lower, paired t-test, n=29, P<0.001). Therefore, a 4.3 cm×3.0 cm escape <span class="hlt">vent</span> was considered appropriate for C. japonica fishing in the artificial reef area. This finding will assist the development of more sustainable and efficient crab fishing methods using accordion-shaped traps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016DSRI..116..118K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016DSRI..116..118K"><span id="translatedtitle">Geochemical characteristics of sinking particles in the Tonga arc hydrothermal <span class="hlt">vent</span> field, southwestern Pacific</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Hyung Jeek; Kim, Jonguk; Pak, Sang Joon; Ju, Se-Jong; Yoo, Chan Min; Kim, Hyun Sub; Lee, Kyeong Yong; Hwang, Jeomshik</p> <p>2016-10-01</p> <p>Studies of sinking particles associated with hydrothermal <span class="hlt">vent</span> fluids may help us to quantify mass transformation processes between hydrothermal <span class="hlt">vent</span> plumes and deposits. Such studies may also help us understand how various <span class="hlt">types</span> of hydrothermal systems influence particle flux and composition. However, the nature of particle precipitation out of hydrothermal <span class="hlt">vent</span> plumes in the volcanic arcs of convergent plate boundaries has not been well studied, nor have the characteristics of such particles been compared with the characteristics of sinking particles at divergent boundaries. We examined sinking particles collected by sediment traps for about 10 days at two sites, each within 200 m of identified hydrothermal <span class="hlt">vents</span> in the south Tonga arc of the southwestern Pacific. The total mass flux was several-fold higher than in the non-hydrothermal southwest tropical Pacific. The contribution of non-biogenic materials was dominant (over 72%) and the contribution of metals such as Fe, Mn, Cu, and Zn was very high compared to their average levels in the upper continental crust. The particle flux and composition indicate that hydrothermal authigenic particles are the dominant source of the collected sinking particles. Overall, our elemental ratios are similar to observations of particles at the divergent plate boundary in the East Pacific Rise (EPR). Thus, the nature of the hydrothermal particles collected in the south Tonga arc is probably not drastically different from particles in the EPR region. However, we observed consistent differences between the two sites within the Tonga arc, in terms of the contribution of non-biogenic material, the radiocarbon content of sinking particulate organic carbon, the ratios of iron to other metals (e.g. Cu/Fe and Zn/Fe), and plume maturity indices (e.g. S/Fe). This heterogeneity within the Tonga arc is likely caused by differences in physical environment such as water depth, phase separation due to subcritical boiling and associated sub</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4734175','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4734175"><span id="translatedtitle">Strong Ion Regulatory Abilities Enable the Crab Xenograpsus testudinatus to Inhabit Highly Acidified Marine <span class="hlt">Vent</span> Systems</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hu, Marian Y.; Guh, Ying-Jey; Shao, Yi-Ta; Kuan, Pou-Long; Chen, Guan-Lin; Lee, Jay-Ron; Jeng, Ming-Shiou; Tseng, Yung-Che</p> <p>2016-01-01</p> <p>Hydrothermal <span class="hlt">vent</span> organisms have evolved physiological adaptations to cope with extreme abiotic conditions including temperature and pH. To date, acid-base regulatory abilities of <span class="hlt">vent</span> organisms are poorly investigated, although this physiological feature is essential for survival in low pH environments. We report the acid-base regulatory mechanisms of a hydrothermal <span class="hlt">vent</span> crab, Xenograpsus testudinatus, endemic to highly acidic shallow-water <span class="hlt">vent</span> habitats with average environment pH-values ranging between 5.4 and 6.6. Within a few hours, X. testudinatus restores extracellular pH (pHe) in response to environmental acidification of pH 6.5 (1.78 kPa pCO2) accompanied by an increase in blood HCO3- levels from 8.8 ± 0.3 to 31 ± 6 mM. Branchial Na+/K+-ATPase (NKA) and V-<span class="hlt">type</span> H+-ATPase (VHA), the major ion pumps involved in branchial acid-base regulation, showed dynamic increases in response to acidified conditions on the mRNA, protein and activity level. Immunohistochemical analyses demonstrate the presence of NKA in basolateral membranes, whereas the VHA is predominantly localized in cytoplasmic vesicles of branchial epithelial- and pillar-cells. X. testudinatus is closely related to other strong osmo-regulating brachyurans, which is also reflected in the phylogeny of the NKA. Accordingly, our results suggest that the evolution of strong ion regulatory abilities in brachyuran crabs that allowed the occupation of ecological niches in euryhaline, freshwater, and terrestrial habitats are probably also linked to substantial acid-base regulatory abilities. This physiological trait allowed X. testudinatus to successfully inhabit one of the world's most acidic marine environments. PMID:26869933</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5892210','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5892210"><span id="translatedtitle">Chimney related energy losses in oil-fired heating systems: Configuration effects and <span class="hlt">venting</span> alternatives</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Butcher, T.; McDonald, R.; Krajewski, R.; Batey, J.</p> <p>1990-12-01</p> <p>Conventional <span class="hlt">venting</span> systems for oil-fired residential heating equipment include the flue connector, a barometric damper, and the chimney. This <span class="hlt">venting</span> arrangement is directly responsible for some of the annual energy losses associated with these heating installations. In the work described in this report a study of the relevant characteristics of burners and dampers was done to permit these energy losses to be estimated as a function of the installation details. The purpose of this work is to determine the potential energy savings which might be realized from alternative <span class="hlt">venting</span> methods in a wide range of situations. The basic draft/flow characteristics of barometric dampers were measured using a flow tunnel arrangement under cold (no combustion) conditions. A range of damper diameters and draft settings were used. Off-cycle draft/flow relations for several burners and heating units with the burner ports sealed were also measured over a range of conditions. Recently, oil burners have become available which have significantly higher static pressure fans. The excess air level provided by these burners is much less sensitive to variations in draft and burners of this <span class="hlt">type</span> might be operated without a barometric damper. Burner fan performance curves for both high and low static pressure units have been measured. Flows through the heating unit and barometric damper flows have been calculated during the on- and off-cycle for a range of configurations as a function of outdoor temperature. The annual energy losses due to the <span class="hlt">venting</span> system were calculated using a bin method. The calculated flows were compared with available field data. To supplement the available data some additional field measurements were taken during this project and are described in this report. 19 refs., 42 figs., 7 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20228114','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20228114"><span id="translatedtitle">Biogeography and biodiversity in sulfide structures of active and inactive <span class="hlt">vents</span> at deep-sea hydrothermal fields of the Southern Mariana Trough.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kato, Shingo; Takano, Yoshinori; Kakegawa, Takeshi; Oba, Hironori; Inoue, Kazuhiko; Kobayashi, Chiyori; Utsumi, Motoo; Marumo, Katsumi; Kobayashi, Kensei; Ito, Yuki; Ishibashi, Jun-ichiro; Yamagishi, Akihiko</p> <p>2010-05-01</p> <p>The abundance, diversity, activity, and composition of microbial communities in sulfide structures both of active and inactive <span class="hlt">vents</span> were investigated by culture-independent methods. These sulfide structures were collected at four hydrothermal fields, both on- and off-axis of the back-arc spreading center of the Southern Mariana Trough. The microbial abundance and activity in the samples were determined by analyzing total organic content, enzymatic activity, and copy number of the 16S rRNA gene. To assess the diversity and composition of the microbial communities, 16S rRNA gene clone libraries including bacterial and archaeal phylotypes were constructed from the sulfide structures. Despite the differences in the geological settings among the sampling points, phylotypes related to the Epsilonproteobacteria and cultured hyperthermophilic archaea were abundant in the libraries from the samples of active <span class="hlt">vents</span>. In contrast, the relative abundance of these phylotypes was extremely low in the libraries from the samples of inactive <span class="hlt">vents</span>. These results suggest that the composition of microbial communities within sulfide structures dramatically changes depending on the degree of hydrothermal activity, which was supported by statistical analyses. Comparative analyses suggest that the abundance, activity and diversity of microbial communities within sulfide structures of inactive <span class="hlt">vents</span> are likely to be comparable to or higher than those in active <span class="hlt">vent</span> structures, even though the microbial community composition is different between these two <span class="hlt">types</span> of <span class="hlt">vents</span>. The microbial community compositions in the sulfide structures of inactive <span class="hlt">vents</span> were similar to those in seafloor basaltic rocks rather than those in marine sediments or the sulfide structures of active <span class="hlt">vents</span>, suggesting that the microbial community compositions on the seafloor may be constrained by the available energy sources. Our findings provide helpful information for understanding the biogeography, biodiversity and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20228114','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20228114"><span id="translatedtitle">Biogeography and biodiversity in sulfide structures of active and inactive <span class="hlt">vents</span> at deep-sea hydrothermal fields of the Southern Mariana Trough.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kato, Shingo; Takano, Yoshinori; Kakegawa, Takeshi; Oba, Hironori; Inoue, Kazuhiko; Kobayashi, Chiyori; Utsumi, Motoo; Marumo, Katsumi; Kobayashi, Kensei; Ito, Yuki; Ishibashi, Jun-ichiro; Yamagishi, Akihiko</p> <p>2010-05-01</p> <p>The abundance, diversity, activity, and composition of microbial communities in sulfide structures both of active and inactive <span class="hlt">vents</span> were investigated by culture-independent methods. These sulfide structures were collected at four hydrothermal fields, both on- and off-axis of the back-arc spreading center of the Southern Mariana Trough. The microbial abundance and activity in the samples were determined by analyzing total organic content, enzymatic activity, and copy number of the 16S rRNA gene. To assess the diversity and composition of the microbial communities, 16S rRNA gene clone libraries including bacterial and archaeal phylotypes were constructed from the sulfide structures. Despite the differences in the geological settings among the sampling points, phylotypes related to the Epsilonproteobacteria and cultured hyperthermophilic archaea were abundant in the libraries from the samples of active <span class="hlt">vents</span>. In contrast, the relative abundance of these phylotypes was extremely low in the libraries from the samples of inactive <span class="hlt">vents</span>. These results suggest that the composition of microbial communities within sulfide structures dramatically changes depending on the degree of hydrothermal activity, which was supported by statistical analyses. Comparative analyses suggest that the abundance, activity and diversity of microbial communities within sulfide structures of inactive <span class="hlt">vents</span> are likely to be comparable to or higher than those in active <span class="hlt">vent</span> structures, even though the microbial community composition is different between these two <span class="hlt">types</span> of <span class="hlt">vents</span>. The microbial community compositions in the sulfide structures of inactive <span class="hlt">vents</span> were similar to those in seafloor basaltic rocks rather than those in marine sediments or the sulfide structures of active <span class="hlt">vents</span>, suggesting that the microbial community compositions on the seafloor may be constrained by the available energy sources. Our findings provide helpful information for understanding the biogeography, biodiversity and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26632131','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26632131"><span id="translatedtitle">Herpes zoster ophthalmicus presenting as orbital abscess along with superior orbital <span class="hlt">fissure</span> syndrome: A case report.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lavaju, Poonam; Badhu, Badri Prasad; Shah, Sangeeta</p> <p>2015-09-01</p> <p>Orbital abscess and superior orbital <span class="hlt">fissure</span> syndrome (SOFS) are rare manifestations of herpes zoster ophthalmicus. Herein, we report a case of orbital abscess along with SOFS in a 2.5-year-old-male child secondary to herpes zoster infection. He presented with a 5-day history of proptosis and ptosis of the right eye that had been preceded by vesicular eruptions on the right forehead and scalp. Computed tomography scan of the head and orbit showed orbital abscess and right cavernous sinus thrombosis. A diagnosis of orbital abscess with SOFS secondary to herpes infection was made. The condition subsequently improved following antiviral therapy, intravenous vancomycin and amikacin, and oral corticosteroids. PMID:26632131</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.V14B..05T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.V14B..05T"><span id="translatedtitle">Inside the <span class="hlt">Vent</span> of the 2011-2012 Cordón Caulle Eruption, Chile: The Nature of a Rhyolitic Ash Plume Source</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tuffen, H.; Castro, J. M.; Schipper, C. I.; Wadsworth, F. B.</p> <p>2014-12-01</p> <p>The 2011-2012 activity at Cordon Caulle has provided an unprecedented opportunity to observe a sustained explosive rhyolitic eruption. An initial 27 hour Plinian phase commenced on 4 June 2011, followed by ten months of hybrid explosive-effusive activity, which generated disruptive ≤6 km ash plumes. In January 2012 our close observations of the active <span class="hlt">vent</span>[1] revealed how episodic release of gas and ash from several sub-<span class="hlt">vents</span> on an incipient lava dome (Fig. 1b) merged to form a sustained ash plume. Sub-<span class="hlt">vents</span> ranged from metric point sources to arcuate fractures (>10 m) in the dome carapace. We visited the <span class="hlt">vent</span> in January 2014, and found two ~50 m-wide, rubble-strewn <span class="hlt">vent</span> areas adjacent to pancake-like obsidian domes, all within a breached, ~100 m-high tuff cone. <span class="hlt">Vent</span> areas consist of fractured obsidian lava strewn by loose, rotated lava blocks ≤5 m across. Prominent red fracture surfaces (Fig. 1 d,e) occur in both the in-situ lava and the blocky veneer; these closely correspond to the <span class="hlt">type</span> of sub-<span class="hlt">vents</span> observed in 2012[1]. They range from smooth, curviplanar surfaces extending over several m to complex smaller-scale surfaces that follow pre-existing cooling joints in the lava carapace. In-situ fracture surfaces display prominent, predominantly vertical grooves and impact marks, but negligible displacement. Surfaces are coated by μm-mm thick veneers of fine-grained ash, to which larger ash-coated clasts have adhered. Veneer thickness and sintering degree strongly decrease towards the upper carapace of the lava. SEM analysis of ash veneers reveals 1) a high proportion of sub-micron clasts, 2) strong clast sintering, 3) abundant ash aggregation textures spanning submicron-mm scales, and 4) local surface scouring and corrosion of glass and phenocrysts. During ash <span class="hlt">venting</span> the smallest particles are preferentially trapped on fracture surfaces and rapidly sintered, encouraging sub-<span class="hlt">vent</span> blockage. Extensive ash aggregation may have been electrostatically aided, with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003AGUFM.B12A0765Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003AGUFM.B12A0765Z&link_type=ABSTRACT"><span id="translatedtitle">Permeability-Porosity Relationships in Deep Sea Hydrothermal <span class="hlt">Vent</span> Deposits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, W.; Gittings, H.; Tivey, M. K.</p> <p>2003-12-01</p> <p>To map out the thermal and chemical regimes within <span class="hlt">vent</span> deposits where micro-and macro-organisms reside requires accurate modeling of mixing and reaction between hydrothermal fluid and seawater within the <span class="hlt">vent</span> structures. However, a critical piece of information, quantitative knowledge of the permeability of <span class="hlt">vent</span> deposits, and how it relates to porosity and pore geometry, is still missing. To address this, systematic laboratory measurements of permeability and porosity were conducted on 3 large <span class="hlt">vent</span> structures from the Mothra Hydrothermal <span class="hlt">vent</span> field on the Endeavor Segment of the Juan de Fuca Ridge. Twenty-five cylindrical cores with diameters of 2.54 cm and various lengths were taken from Phang (a tall sulfide-dominated spire that was not actively <span class="hlt">venting</span> when sampled), Roane (a lower temperature spire with dense macrofaunal communities growing on its sides that was <span class="hlt">venting</span> diffuse fluid of < 300° C) and Finn (an active black smoker with a well-defined inner conduit that was <span class="hlt">venting</span> 302° C fluids prior to recovery (Delaney et al., 2000; Kelley et al, 2000)). Measurements were made to obtain porosity and permeability of these drill cores using a helium porosimeter (UltraPoreTM300) and a nitrogen permeameter (UltrapermTM400) from Core Laboratories Instruments. The porosimeter uses Boyle's law to determine pore volume from the expansion of a know mass of helium into a calibrated sample holder, whereas the permeameter uses Darcy's law to determine permeability by measuring the steady-state flow rate through the sample under a given pressure gradient. A moderate confining pressure of 1.38 MPa was applied during the measurements to prevent leakage between the sample surface and the sample holder. The permeability and porosity relationship is best described by two different power law relationships with exponents of ˜9 (group I) and ˜3 (group II), respectively. Microstructural observations suggest that the difference in the two permeability-porosity relationships</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.4504G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.4504G"><span id="translatedtitle">Shift from magmatic to phreatomagmatic explosion controlled by the evolution of lateral <span class="hlt">fissure</span> eruption in Suoana Crater, Miyakejima</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geshi, Nobuo; Nemeth, Karoly; Noguchi, Rina; Oikawa, Teruki</p> <p>2016-04-01</p> <p>Combined analysis of the proximal deposit and exposed feeder-diatreme structure of the Suoana Crater of Miyakejima reveals the process of magma-water interaction controlled by the evolution of lateral <span class="hlt">fissure</span> eruption in a stratovolcanic edifice. The Suoana Crater, an oval maar with 400 x 300 m across is one of the craters of the Suoana-Kazahaya crater chain which is formed during a <span class="hlt">fissure</span> eruption in the 7th Century. The eruption <span class="hlt">fissure</span> extends ~3 km from the summit area (~700 m asl) to the lower-flank area (~200m asl). The eruption <span class="hlt">fissure</span> consists of upper maar-chain (>450 m asl) and lower scora-cone chain. As the wall of the 2000 AD caldera truncated at near the center of the Suoana Crater, the vertical section of the feeder dike - diatreme - maar system of the Suoana Crater is exposed in the caldera wall (Geshi et al., 2011). The ejected materials from the Suoana crater indicate the transition of eruption style from magmatic to phreatomagmatic. The juvenile clasts in the lower half of the deposit exhibit spatter-like shape, indicating the typical deposit from a vigorous fire fountain. Contrary, the juvenile clasts in the upper half are less vesiculated and exhibit cauliflower-shape, indicating the typical phreatomagmatic activity. This transition indicates that the magma-water interaction started at the middle of the eruption. Judging from the ratio of the thickness of the lower and upper parts, the contrast of the content of juvenile clasts, and bulk density of the deposit, the total ejected volume of magma is larger in the lower part compare to the upper part. The transition from magmatic to phreatomagmatic occurred only in the upper half of the eruption <span class="hlt">fissure</span>, including the Suoana crater, whereas the lower half of the <span class="hlt">fissure</span> continued dry magmatic eruption throughout their activity. The limited distribution of phreatomagmatic activity can be resulted by the magma extraction from the upper feeder dike system to the lower eruption <span class="hlt">fissure</span> as it</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GGG....16.2661W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GGG....16.2661W"><span id="translatedtitle">Geology, sulfide geochemistry and supercritical <span class="hlt">venting</span> at the Beebe Hydrothermal <span class="hlt">Vent</span> Field, Cayman Trough</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Webber, Alexander P.; Roberts, Stephen; Murton, Bramley J.; Hodgkinson, Matthew R. S.</p> <p>2015-09-01</p> <p>The Beebe <span class="hlt">Vent</span> Field (BVF) is the world's deepest known hydrothermal system, at 4960 m below sea level. Located on the Mid-Cayman Spreading Centre, Caribbean, the BVF hosts high temperature (˜401°C) "black smoker" <span class="hlt">vents</span> that build Cu, Zn and Au-rich sulfide mounds and chimneys. The BVF is highly gold-rich, with Au values up to 93 ppm and an average Au:Ag ratio of 0.15. Gold precipitation is directly associated with diffuse flow through "beehive" chimneys. Significant mass-wasting of sulfide material at the BVF, accompanied by changes in metal content, results in metaliferous talus and sediment deposits. Situated on very thin (2-3 km thick) oceanic crust, at an ultraslow spreading centre, the hydrothermal system circulates fluids to a depth of ˜1.8 km in a basement that is likely to include a mixture of both mafic and ultramafic lithologies. We suggest hydrothermal interaction with chalcophile-bearing sulfides in the mantle rocks, together with precipitation of Au in beehive chimney structures, has resulted in the formation of a Au-rich volcanogenic massive sulfide (VMS) deposit. With its spatial distribution of deposit materials and metal contents, the BVF represents a modern day analogue for basalt hosted, Au-rich VMS systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4279319','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4279319"><span id="translatedtitle">Comparative study of Ksharasutra suturing and Lord's anal dilatation in the management of Parikartika (chronic <span class="hlt">fissure</span>-in-ano)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dudhamal, Tukaram S.; Baghel, Madhav Singh; Bhuyan, Chaturbhuja; Gupta, Sanjay Kumar</p> <p>2014-01-01</p> <p>Background: Parikartika resembles <span class="hlt">fissure</span>-in-ano which is very common among all ano-rectal disorders. In Ayurvedic texts, Parikartika is described as a complication of Vamana and Virechana as well as complication of Atisara. Ksharasutra was proved successful in the management of fistula-in-ano, piles, and there is a need to try its efficacy in <span class="hlt">fissure</span>-in-ano. Aim: To evaluate the role of Ksharasutra suturing (KSS) in <span class="hlt">fissure</span> bed in chronic <span class="hlt">fissure</span>-in-ano. Materials and Methods: Total 100 patients of chronic <span class="hlt">fissure</span>-in-ano were selected and randomly divided into two groups (50 in each group). In group-A, patients were undergone by KSS; while in patients of Group-B Lord's anal dilatation followed by KSS was done under spinal anesthesia. The KSS was done once and after slough out of Ksharasutra, the wound was treated for 4 weeks and assessment of the result was done on the basis of gradation adopted. Results: The pain relief on 14th day in Group-A was 86% while in Group-B 100% was observed. As on 7th day in Group-A, oozing was stopped in 68% patients, while in Group-B, oozing was stopped in 82% patients. On 21st day, Group-B showed more healing (85%) as compared to Group-A (69%). In this study 68% of patients were cured. Conclusion: In Group-B (KSS with Lord's anal dilatation) patients were cured early as compared to patients of Group-A (KSS alone). PMID:25558158</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008epsc.conf..115L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008epsc.conf..115L"><span id="translatedtitle">Morphology of cone-fields in SW Elysium Planitia - Traces of hydrothermal <span class="hlt">venting</span> on Mars?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lanz, J. K.; Saric, M. B.</p> <p>2008-09-01</p> <p> wide. There are distinct morphological changes both within the band from north to south and along the band from east to west (Fig. 2). The cones are mostly circular but elongated, irregular forms are common. They are of varying size with basal diameters ranging from 20 to 200 meters, though most (single) cones have basal diameters below 100 meters. The heights of the cones are difficult to determine as their sizes are far below the resolution limits of either MOLA or HRSC stereo data, yet photoclinometric calculations have given approximate heights between ~ 10 up to several dozens of meters. Often the cones show hardly any elevation above the surroundings (e.g. Fig. 2c, e or f). Most of the APCs have steep convex flanks and large summit pits with diameters at least half as wide as their bases. The overall morphology of the cones changes from S to N with distance from the APF and from E to W along the edges of the APF. Toward the south, close to the strongly eroded borders of the APF, broad ridges and elongated domes are dominant. They form a narrow band approximately 2 km wide. The ridges and domes are a few dozen to several hundred meters long and between 10 to 50 meters wide and show numerous cracks and <span class="hlt">fissures</span>. They are often topped by small cones, elongated pits and remnants of APF sediments. Further north follows a rather abrupt transition from the ridged area to more cone-dominated regions. Here single cones are prevalent with a more random distribution. Their number decreases rapidly with increasing distance from the APF and approximately 3 km off the southern edge of the APF no further cones are found. Hydrothermal <span class="hlt">venting</span> on Mars? Morphology and stratigraphic relationships indicate that the cones are young and that they have, at least in places, developed inside the APF complex. APF remnants can be found covering the central pits of cones and APF units have been tilted and eroded by coneforming processes. Furthermore, cones are mainly found inside a narrow</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRB..119.4708G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRB..119.4708G"><span id="translatedtitle">Morphology and dynamics of explosive <span class="hlt">vents</span> through cohesive rock formations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Galland, O.; Gisler, G. R.; Haug, Ø. T.</p> <p>2014-06-01</p> <p>Shallow explosive volcanic processes, such as kimberlite volcanism and phreatomagmatic and phreatic activity, produce volcanic <span class="hlt">vents</span> exhibiting a wide variety of morphologies, including vertical pipes and V-shaped <span class="hlt">vents</span>. In this study we report on experimental and numerical models designed to capture a range of <span class="hlt">vent</span> morphologies in an eruptive system. Using dimensional analysis, we identified key governing dimensionless parameters, in particular the gravitational stress-to-fluid pressure ratio (Π2 = P/ρgh) and the fluid pressure-to-host rock strength ratio (Π3 = P/C). We used combined experimental and numerical models to test the effects of these parameters. The experiments were used to test the effect of Π2 on <span class="hlt">vent</span> morphology and dynamics. A phase diagram demonstrates a separation between two distinct morphologies, with vertical structures occurring at high values of Π2 and diagonal ones at low values of Π2. The numerical simulations were used to test the effect of Π3 on <span class="hlt">vent</span> morphology and dynamics. In the numerical models we see three distinct morphologies: vertical pipes are produced at high values of Π3, diagonal pipes at low values of Π3, and horizontal sills at intermediate values of Π3. Our results show that vertical pipes form by plasticity-dominated yielding in high-energy systems (high Π2 and Π3), whereas diagonal and horizontal <span class="hlt">vents</span> dominantly form by fracturing in lower energy systems (low Π2 and Π3). Although our models are two-dimensional, they suggest that circular pipes result from plastic yielding of the host rock in a high-energy regime, whereas V-shaped volcanic <span class="hlt">vents</span> result from fracturing of the host rock in lower energy systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24862554','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24862554"><span id="translatedtitle">Spatial patterns of Aquificales in deep-sea <span class="hlt">vents</span> along the Eastern Lau Spreading Center (SW Pacific).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ferrera, Isabel; Banta, Amy B; Reysenbach, Anna-Louise</p> <p>2014-09-01</p> <p>The microbial diversity associated with actively <span class="hlt">venting</span> deep-sea hydrothermal deposits is tightly connected to the geochemistry of the hydrothermal fluids. Although the dominant members of these deposits drive the structure of the microbial communities, it is less well understood whether the lower abundance groups are as closely connected to the geochemical milieu, or driven perhaps by biotic factors such as microbial community interactions. We used the natural geochemical gradients that exist in the back-arc basin, Eastern Lau Spreading Center and Valu-Fa Ridge (ELSC/VFR) in the Southwestern Pacific, to explore whether the chemolithotrophic Aquificales are influenced by geographical location, host-rock of the <span class="hlt">vent</span> field or deposit <span class="hlt">type</span>. Using a combination of cloning, DNA fingerprinting (DGGE) and enrichment culturing approaches, all genera of this order previously described at marine <span class="hlt">vents</span> were detected, i.e., Desulfurobacterium, Thermovibrio, Aquifex, Hydrogenivirga, Persephonella and Hydrogenothermus. The comparison between clone libraries and DGGE showed similar patterns of distribution of different Aquificales whereas results differed for the enrichment cultures that were retrieved. However, the use of cultivation-based and -independent methods did provide complementary phylogenetic diversity overview of the Aquificales in these systems. Together, this survey revealed that the ELSC/VFR contains some of the largest diversity of Aquificales ever reported at a deep-sea <span class="hlt">vent</span> area, that the diversity patterns are tied to the geography and geochemistry of the system, and that this geochemical diverse back-arc basin may harbor new members of the Aquificales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.V41B2076G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.V41B2076G"><span id="translatedtitle">Bacterial Diets of Primary Consumers at Hydrothermal <span class="hlt">Vents</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Govenar, B.; Shank, T. M.</p> <p>2008-12-01</p> <p>Chemical energy produced by mixing hydrothermal fluids and seawater supports dense biological communities on mid-ocean ridges. The base of the food web at deep-sea hydrothermal <span class="hlt">vents</span> is formed by chemolithoautotrophic bacteria that use the energy from the oxidation of reduced chemicals to fix inorganic carbon into simple sugars. With the exception of a few species that have chemolithoautotropic bacterial symbionts, most of the <span class="hlt">vent</span>-endemic macrofauna are heterotrophs that feed on free-living bacteria, protists, and other invertebrates. The most abundant and diverse group of primary consumers in hydrothermal <span class="hlt">vent</span> communities belong to the Gastropoda, particularly the patellomorph limpets. Gastropod densities can be as high as 2000 individuals m-2, and there can be as many as 13 species of gastropods in a single aggregation of the siboglinid tubeworm Riftia pachyptila and more than 40 species along the East Pacific Rise. Some gastropods are ubiquitous and others are found in specific microhabitats, stages of succession, or associated with different foundation species. To determine the mechanisms of species coexistence (e.g. resource partitioning or competition) among hydrothermal <span class="hlt">vent</span> primary consumers and to track the flow of energy in hydrothermal <span class="hlt">vent</span> communities, we employed molecular genetic techniques to identify the gut contents of four species of co-occurring hydrothermal <span class="hlt">vent</span> gastropods, Eulepetopsis vitrea, Lepetodrilus elevatus, Lepetodrilus ovalis and Lepetodrilus pustulosus, collected from a single diffuse-flow hydrothermal <span class="hlt">vent</span> site on the East Pacific Rise. Unique haplotypes of the 16S gene that fell among the epsilon-proteobacteria were found in the guts of every species, and two species had gut contents that were similar only to epsilon-proteobacteria. Two species had gut contents that also included haplotypes that clustered with delta-proteobacteria, and one species had gut contents that clustered with alpha- proteobacteria. Differences in the diets</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900009170','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900009170"><span id="translatedtitle">Zero-Gravity Vortex <span class="hlt">Vent</span> and PVT Gaging System</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Downey, M. G.; Trevathan, J. T.</p> <p>1989-01-01</p> <p>Space Station and satellite reservicing will require the ability to <span class="hlt">vent</span> gas on orbit from liquid supply or storage tanks and to gage liquid quantity under microgravity conditions. In zero gravity, (zero-g) the vortex <span class="hlt">vent</span> is capable of <span class="hlt">venting</span> gas from a tank of liquid containing gas randomly distributed as bubbles. The concept uses a spinning impeller to create centrifugal force inside a vortex tube within a tank. This creates a gas pocket and forces the liquid through a venturi and back into the tank. Gas is then <span class="hlt">vented</span> from the gas pocket through a liquid detector and then out through an exhaust port. If the liquid detector senses liquid in the <span class="hlt">vent</span> line, the fluid is directed to the low-pressure port on the venturi and is returned to the tank. The advantages of this system is that it has no rotating seals and is compatible with most corrosive and cryogenic fluids. A prototype was designed and built at the NASA Johnson Space Center and flown on the KC-135 zero-g aircraft. During these test flights, where microgravity conditions are obtained for up to 30 sec, the prototype demonstrated that less than 0.10 percent of the volume of fluid <span class="hlt">vented</span> was liquid when the tank was half full of liquid. The pressure volume temperature (PVT) gaging system is used in conjunction with the vortex <span class="hlt">vent</span> to calculate the amount of liquid remaining in a tank under microgravity conditions. The PVT gaging system is used in conjunction with the vortex <span class="hlt">vent</span> to gage liquid quantity in zero or low gravity. The system consists of a gas compressor, accumulator, and temperature and pressure instrumentation. To measure the liquid in a tank a small amount of gas is <span class="hlt">vented</span> from the tank to the compressor and compressed into the accumulator. Pressure and temperature in the tank and accumulator are measured before and after the gas transfer occurs. Knowing the total volume of the tank, the volume of the accumulator, the volume of the intermediate lines, and initial and final pressures and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10149013','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10149013"><span id="translatedtitle">In vitro comparison tests of three LV <span class="hlt">vent</span> valves.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lewis, G S; Czaplicka, C</p> <p>1990-01-01</p> <p>Many surgical teams employ a sump pump to <span class="hlt">vent</span> the left ventricle (LV). The problems associated with this technique are related to safety and convenience. If the flow is accidentally reversed in the LV <span class="hlt">vent</span> line, air embolism accidents and subsequent litigation may be the result. If the cannula is occluded, it is inconvenient to juggle pump speed to prevent the line from collapsing while maintaining gentle but adequate suction. In this study we in vitro tested three commercially available LV <span class="hlt">vent</span> valves (RLV-2100 "B," VRV-200 B, H-130) (GLV did not wish to send samples for comparison at the time of this study). Each valve was designed to: regulate suction in the LV <span class="hlt">vent</span> line; prevent the flow of air towards the heart; and <span class="hlt">vent</span> downstream pressure to the atmosphere. Each valve was tested for suction at various flow rates, pressure heads, and for the presence of air leakage during reversed flow conditions. The results of pressure and suction tests during normal flow and occluded line conditions have been tabulated. We found the RLV-2100 "B" offers the safest combination of suction control and pressure relief. The most astonishing fact learned was the RLV-2100 "B" was the only valve which prevented the flow of air towards the heart during reversed flow. As a result, we elected to use only this valve in our clinical practice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70028504','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70028504"><span id="translatedtitle">A ubiquitous thermoacidophilic archaeon from deep-sea hydrothermal <span class="hlt">vents</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Reysenbach, A.-L.; Liu, Yajing; Banta, A.B.; Beveridge, T.J.; Kirshtein, J.D.; Schouten, S.; Tivey, M.K.; Von Damm, K. L.; Voytek, M.A.</p> <p>2006-01-01</p> <p>Deep-sea hydrothermal <span class="hlt">vents</span> are important in global biogeochemical cycles, providing biological oases at the sea floor that are supported by the thermal and chemical flux from the Earth's interior. As hot, acidic and reduced hydrothermal fluids mix with cold, alkaline and oxygenated sea water, minerals precipitate to form porous sulphide-sulphate deposits. These structures provide microhabitats for a diversity of prokaryotes that exploit the geochemical and physical gradients in this dynamic ecosystem. It has been proposed that fluid pH in the actively <span class="hlt">venting</span> sulphide structures is generally low (pH < 4.5), yet no extreme thermoacidophile has been isolated from <span class="hlt">vent</span> deposits. Culture-independent surveys based on ribosomal RNA genes from deep-sea hydrothermal deposits have identified a widespread euryarchaeotal lineage, DHVE2 (deep-sea hydrothermal <span class="hlt">vent</span> euryarchaeotic 2). Despite the ubiquity and apparent deep-sea endemism of DHVE2, cultivation of this group has been unsuccessful and thus its metabolism remains a mystery. Here we report the isolation and cultivation of a member of the DHVE2 group, which is an obligate thermoacidophilic sulphur- or iron-reducing heterotroph capable of growing from pH 3.3 to 5.8 and between 55 and 75??C. In addition, we demonstrate that this isolate constitutes up to 15% of the archaeal population, providing evidence that thermoacidophiles may be key players in the sulphur and iron cycling at deep-sea <span class="hlt">vents</span>. ?? 2006 Nature Publishing Group.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830061540&hterms=slug&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dslug','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830061540&hterms=slug&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dslug"><span id="translatedtitle">Steam chugging analysis in single-<span class="hlt">vent</span> vapor injection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lee, C. K. B.; Chan, C. K.</p> <p>1982-01-01</p> <p>A complete cycle of the periodic steam chugging phenomenon is analyed. Steam velocity and pressure variations in the <span class="hlt">vent</span> are described by one-dimensional conservation equations. This is coupled either to the water slug model when water is in the <span class="hlt">vent</span>, or, the infinite pool spherical bubble model at the <span class="hlt">vent</span> exit during bubble growth. An isolated spherical bubble model is used for computing the collapse pressures. Comparisons of the model predictions with the UCLA 1/12-scale and the Japan 1/6-scale data indicate that the <span class="hlt">vent</span>-pipe model predicts the <span class="hlt">vent</span>-clearing times and the bubble growth times well. In addition, the predicted maximum chugging heights compared well with those measured in the Japan data. On bubble collapse pressures, the comparison with the spherical bubble model predictions is only fair. The model generally overpredicts the magnitude of the spikes. On examining the effects of pool subcooling and steam mass flux, general agreement is found between the predicted trends and those measured.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23785361','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23785361"><span id="translatedtitle">Microbiological characterization of post-eruption "snowblower" <span class="hlt">vents</span> at Axial Seamount, Juan de Fuca Ridge.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meyer, Julie L; Akerman, Nancy H; Proskurowski, Giora; Huber, Julie A</p> <p>2013-01-01</p> <p>Microbial processes within the subseafloor can be examined during the ephemeral and uncommonly observed phenomena known as snowblower <span class="hlt">venting</span>. Snowblowers are characterized by the large quantity of white floc that is expelled from the seafloor following mid-ocean ridge eruptions. During these eruptions, rapidly cooling lava entrains seawater and hydrothermal fluids enriched in geochemical reactants, creating a natural bioreactor that supports a subseafloor microbial "bloom." Previous studies hypothesized that the eruption-associated floc was made by sulfide-oxidizing bacteria; however, the microbes involved were never identified. Here we present the first molecular analysis combined with microscopy of microbial communities in snowblower <span class="hlt">vents</span> from samples collected shortly after the 2011 eruption at Axial Seamount, an active volcano on the Juan de Fuca Ridge. We obtained fluid samples and white flocculent material from active snowblower <span class="hlt">vents</span> as well as orange flocculent material found on top of newly formed lava flows. Both flocculent <span class="hlt">types</span> revealed diverse cell <span class="hlt">types</span> and particulates when examined by phase contrast and scanning electron microscopy (SEM). Distinct archaeal and bacterial communities were detected in each sample <span class="hlt">type</span> through Illumina tag sequencing of 16S rRNA genes and through sequencing of the sulfide oxidation gene, soxB. In fluids and white floc, the dominant bacteria were sulfur-oxidizing Epsilonproteobacteria and the dominant archaea were thermophilic Methanococcales. In contrast, the dominant organisms in the orange floc were Gammaproteobacteria and Thaumarchaeota Marine Group I. In all samples, bacteria greatly outnumbered archaea. The presence of anaerobic methanogens and microaerobic Epsilonproteobacteria in snowblower communities provides evidence that these blooms are seeded by subseafloor microbes, rather than from microbes in bottom seawater. These eruptive events thus provide a unique opportunity to observe subseafloor microbial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23785361','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23785361"><span id="translatedtitle">Microbiological characterization of post-eruption "snowblower" <span class="hlt">vents</span> at Axial Seamount, Juan de Fuca Ridge.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meyer, Julie L; Akerman, Nancy H; Proskurowski, Giora; Huber, Julie A</p> <p>2013-01-01</p> <p>Microbial processes within the subseafloor can be examined during the ephemeral and uncommonly observed phenomena known as snowblower <span class="hlt">venting</span>. Snowblowers are characterized by the large quantity of white floc that is expelled from the seafloor following mid-ocean ridge eruptions. During these eruptions, rapidly cooling lava entrains seawater and hydrothermal fluids enriched in geochemical reactants, creating a natural bioreactor that supports a subseafloor microbial "bloom." Previous studies hypothesized that the eruption-associated floc was made by sulfide-oxidizing bacteria; however, the microbes involved were never identified. Here we present the first molecular analysis combined with microscopy of microbial communities in snowblower <span class="hlt">vents</span> from samples collected shortly after the 2011 eruption at Axial Seamount, an active volcano on the Juan de Fuca Ridge. We obtained fluid samples and white flocculent material from active snowblower <span class="hlt">vents</span> as well as orange flocculent material found on top of newly formed lava flows. Both flocculent <span class="hlt">types</span> revealed diverse cell <span class="hlt">types</span> and particulates when examined by phase contrast and scanning electron microscopy (SEM). Distinct archaeal and bacterial communities were detected in each sample <span class="hlt">type</span> through Illumina tag sequencing of 16S rRNA genes and through sequencing of the sulfide oxidation gene, soxB. In fluids and white floc, the dominant bacteria were sulfur-oxidizing Epsilonproteobacteria and the dominant archaea were thermophilic Methanococcales. In contrast, the dominant organisms in the orange floc were Gammaproteobacteria and Thaumarchaeota Marine Group I. In all samples, bacteria greatly outnumbered archaea. The presence of anaerobic methanogens and microaerobic Epsilonproteobacteria in snowblower communities provides evidence that these blooms are seeded by subseafloor microbes, rather than from microbes in bottom seawater. These eruptive events thus provide a unique opportunity to observe subseafloor microbial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RMRE...49..763C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RMRE...49..763C"><span id="translatedtitle">Mechanical Behavior of Brittle Rock-Like Specimens with Pre-existing <span class="hlt">Fissures</span> Under Uniaxial Loading: Experimental Studies and Particle Mechanics Approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, Ri-hong; Cao, Ping; Lin, Hang; Pu, Cheng-zhi; Ou, Ke</p> <p>2016-03-01</p> <p>Joints and <span class="hlt">fissures</span> with similar orientation or characteristics are common in natural rocks; the inclination and density of the <span class="hlt">fissures</span> affect the mechanical properties and failure mechanism of the rock mass. However, the strength, crack coalescence pattern, and failure mode of rock specimens containing multi-<span class="hlt">fissures</span> have not been studied comprehensively. In this paper, combining similar material testing and discrete element numerical method (PFC2D), the peak strength and failure characteristics of rock-like materials with multi-<span class="hlt">fissures</span> are explored. Rock-like specimens were made of cement and sand and pre-existing <span class="hlt">fissures</span> created by inserting steel shims into cement mortar paste and removing them during curing. The peak strength of multi-<span class="hlt">fissure</span> specimens depends on the <span class="hlt">fissure</span> angle α (which is measured counterclockwise from horizontal) and <span class="hlt">fissure</span> number ( N f). Under uniaxial compressional loading, the peak strength increased with increasing α. The material strength was lowest for α = 25°, and highest for α = 90°. The influence of N f on the peak strength depended on α. For α = 25° and 45°, N f had a strong effect on the peak strength, while for higher α values, especially for the 90° sample, there were no obvious changes in peak strength with different N f. Under uniaxial compression, the coalescence modes between the <span class="hlt">fissures</span> can be classified into three categories: S-mode, T-mode, and M-mode. Moreover, the failure mode can be classified into four categories: mixed failure, shear failure, stepped path failure, and intact failure. The failure mode of the specimen depends on α and N f. The peak strength and failure modes in the numerically simulated and experimental results are in good agreement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1715136M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1715136M"><span id="translatedtitle">Volcanic field elongation, <span class="hlt">vent</span> distribution and tectonic evolution of continental rift: The Main Ethiopian Rift example</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mazzarini, Francesco; Le Corvec, Nicolas; Isola, Ilaria; Favalli, Massimiliano</p> <p>2015-04-01</p> <p>Magmatism and faulting operate in continental rifts and interact at a variety of scales, however their relationship is complex. The African rift, being the best example for both active continental rifting and magmatism, provides the ideal location to study the interplay between the two mechanisms. The Main Ethiopian Rift (MER), which connects the Afar depression in the north with the Turkana depression and Kenya Rift to the south, consists of two distinct systems of normal faults and its floor is scattered with volcanic fields formed by tens to several hundreds monogenetic, generally basaltic, small volcanoes and composite volcanoes and small calderas. The distribution of <span class="hlt">vents</span> defines the overall shape of the volcanic field. Previous work has shown that the distribution of volcanic <span class="hlt">vents</span> and the shape of a field are linked to its tectonic environment and its magmatic system. In order to distinguish the impact of each mechanism, we analyzed four volcanic fields located at the boundary between the central and northern MER, three of them (Debre Zeyit, Wonji and Kone) grew in the rift valley and one (Akaki) on the western rift shoulder. The elongation and shape of the fields were analyzed based on their <span class="hlt">vent</span> distribution using the Principal Component Analysis (PCA), the <span class="hlt">Vent-to-Vent</span> Distance (VVD), and the two dimensional symmetric Gaussian kernel density estimate methods. We extracted from these methods several parameters characterizing the spatial distribution of points (e.g., eccentricity (e), eigenvector index (evi), angular dispersion (Da)). These parameters allow to define at least three <span class="hlt">types</span> of shape for volcanic fields: strong elongate (line and ellipse), bimodal/medium elongate (ellipse) and dispersed (circle) shapes. Applied to the natural example, these methods well differentiate each volcanic field. For example, the elongation of the field increases from shoulder to rift axis inversely to the angular dispersion. In addition, the results show that none of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1211022R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1211022R"><span id="translatedtitle">Analysis of displacements and <span class="hlt">fissure</span> structures on a slow-moving landslide through very high-resolution orthophoto mosaicing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rothmund, Sabrina; Joswig, Manfred; Niethammer, Uwe; Malet, Jean-Philippe</p> <p>2010-05-01</p> <p>Very high-resolution multi-temporal images with a ground resolution of a few centimeters allowed to detect and analyze displacements and <span class="hlt">fissure</span> patterns of the Super-Sauze landslide (Southern French Alps). Images taken by an unmanned aerial vehicle (UAV) during a flight campaign in October 2008 have been used to produce a very high-resolution orthophoto-mosaic of the landslide. In this study, a set of 59 of a total of 1486 images was selected and photogrammetrically processed using different non-parametric rectification approaches (projective transformation, piecewise affine transformation and polynomial transformations of the second and third order). The generated orthophoto-mosaic covers the entire landslide area of 0.09 km² with a ground resolution of 3 to 8 cm. The comparison of this UAV-based orthophoto-mosaic with an orthophotograph from May 2007 (ground resolution of 20 cm) allowed the characterization of the horizontal displacements of the landslide. Displacement vectors were estimated by visually inspecting the images to identify distinct features (rocks, boulders and vegetation patches) in the two orthophotographs. This approach was chosen because of the high dynamics of the landslide and the disadvantageous long period between the repeated image acquisitions. Displacements between 7.1 and 55.4 m in varying directions have been detected and areas of different dynamics could be distinguished for the period between May 2007 and October 2008. Various structures, in particular <span class="hlt">fissures</span> of different distributions and orientations, could be resolved in the UAV-based orthophoto-mosaic. The similarity of the observed <span class="hlt">fissures</span> with glacial crevasses is striking and suggests a similar genesis. The identified longitudinal, transverse and cross-shaped <span class="hlt">fissures</span> are linked to abrupt changes of in-situ crest orientation in the shallow subsurface. The observed shear <span class="hlt">fissures</span> occur at the lateral boundary of emerging in-situ crests. The <span class="hlt">fissure</span> genesis could be traced</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812395T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812395T"><span id="translatedtitle">Interaction between central volcanoes and <span class="hlt">fissure</span> swarms along divergent plate boundaries: an example from Askja Volcano, Northern Iceland.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trippanera, Daniele; Ruch, Joel; Acocella, Valerio; Urbani, Stefano; Thordarson, Thor</p> <p>2016-04-01</p> <p>Central volcanoes located along divergent plate boundaries are typically part of a larger volcanic system that consists of a central edifice and a <span class="hlt">fissure</span> swarm through which magma propagates and spreads plates apart. Regional normal faults and graben structures develop within the volcanic system, also dissecting portions of the central volcano with ring-faults faults and eruptive <span class="hlt">fissures</span> related to the caldera structure. Both the <span class="hlt">fissure</span> swarm and the caldera structure influence the pathway of the ascending magma, however, the influences of the structures on magma propagation and vice versa are not well defined and understood. Here we aim to understand the relationship between the activity of the central volcano structures (e.g. caldera ring faults, radial dykes and cone sheets) and those of the <span class="hlt">fissure</span> swarm (e.g. regional normal faults, regional dikes). We focus on Askja volcano, located in the Northern Volcanic Zone of Iceland. It is comprised of three nested calderas, largely filled in with subaerial basaltic lava flows and surrounded by a massive hyaloclastite mountain on the Eastern side. Formation of the youngest, the Öskjuvatn caldera, was initiated during the 1874-1876 rifting episode on the Askja system. This major event was followed by several localized radial and circumferential magmatic intrusions taking place along the new-formed caldera ring fault, as well as intruding in the <span class="hlt">fissure</span> swarm related to the regional tectonics. In order to characterize the influence of the caldera structure on the regional tectonics, we analysed the structural framework of the caldera and direct surroundings using remote sensing (optical imagery and high resolution DEM from TanDEM-X data). Then we made detailed field measurements (500 data) by analysing azimuth, dip, and opening of eruptive <span class="hlt">fissures</span>, dikes, faults and extension fractures. Both remote sensing and field measurements have been then integrated producing a detailed structural map of Askja. Our results show</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS24B..07T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS24B..07T"><span id="translatedtitle">Post-drilling hydrothermal <span class="hlt">vent</span> and associated biological activities seen through artificial hydrothermal <span class="hlt">vents</span> in the Iheya North field, Okinawa Trough</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takai, K.; Kawagucci, S.; Miyazaki, J.; Watsuji, T.; Ishibashi, J.; Yamamoto, H.; Nozaki, T.; Kashiwabara, T.; Shibuya, T.</p> <p>2012-12-01</p> <p>In 2010, IODP Expedition 331 was conducted in the Iheya North Field, the Okinawa Trough and drilled several sites in hydrothermally active subseafloor. In addition, during the IODP Expedition 331, four new hydrothermal <span class="hlt">vents</span> were created. These post-drilling artificial hydrothermal <span class="hlt">vents</span> provide excellent opportunities to investigate the physical, chemical and microbiological characteristics of the previously unexplored subseafloor hydrothermal fluid reservoirs, and to monitor and estimate how the anthropogenic drilling behaviors affect the deep-sea hydrothermal <span class="hlt">vent</span> ecosystem. We were very much interested in the difference of hydrothermal fluid chemistry between the natural hydrothermal <span class="hlt">vents</span> and the artificial hydrothermal <span class="hlt">vents</span>. The IODP porewater chemistry of the cores pointed to the density-driven stratification of the phase-separated hydrothermal fluids and the natural <span class="hlt">vent</span> fluids were likely derived only from the shallower vapor-enriched phases. However, the artificial hydrothermal <span class="hlt">vents</span> had deeper fluid sources in the subseafloor hydrothermal fluid reservoirs composed of vapor-lost (Cl-enriched) phases. The fluids from the artificial hydrothermal <span class="hlt">vents</span> were sampled by ROV at 5, 12 and 18 months after the IODP expedition. The artificial hydrothermal <span class="hlt">vent</span> fluids were slightly enriched with Cl as compared to the natural hydrothermal <span class="hlt">vent</span> fluids. Thus, the artificial hydrothermal <span class="hlt">vents</span> successfully entrained the previously unexplored subseafloor hydrothermal fluids. The newly created hydrothermal <span class="hlt">vents</span> also hosted the very quickly grown, enormous chimney structures, of which mineral compositions were highly variable among the <span class="hlt">vents</span>. However, the quickly grown C0016B and C0016D <span class="hlt">vent</span> chimneys were found to be typical Kuroko ore even though the chimney growth rates in the artificial <span class="hlt">vents</span> were extremely faster than those in the natural <span class="hlt">vents</span>. In addition, the IODP drilling operation not only created new hydrothermal <span class="hlt">vents</span> by deep drilling but also induced the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. Their policies may differ from this site.</small> </div> </center> <div id="footer-wrapper"> <div class="footer-content"> <div id="footerOSTI" class=""> <div class="row"> <div class="col-md-4 text-center col-md-push-4 footer-content-center"><small><a href="http://www.science.gov/disclaimer.html">Privacy and Security</a></small> <div class="visible-sm visible-xs push_footer"></div> </div> <div class="col-md-4 text-center col-md-pull-4 footer-content-left"> <img src="https://www.osti.gov/images/DOE_SC31.png" alt="U.S. Department of Energy" usemap="#doe" height="31" width="177"><map style="display:none;" name="doe" id="doe"><area shape="rect" coords="1,3,107,30" href="http://www.energy.gov" alt="U.S. Deparment of Energy"><area shape="rect" coords="114,3,165,30" href="http://www.science.energy.gov" alt="Office of Science"></map> <a ref="http://www.osti.gov" style="margin-left: 15px;"><img src="https://www.osti.gov/images/footerimages/ostigov53.png" alt="Office of Scientific and Technical Information" height="31" width="53"></a> <div class="visible-sm visible-xs push_footer"></div> </div> <div class="col-md-4 text-center footer-content-right"> <a href="http://www.osti.gov/nle"><img src="https://www.osti.gov/images/footerimages/NLElogo31.png" alt="National Library of Energy" height="31" width="79"></a> <a href="http://www.science.gov"><img src="https://www.osti.gov/images/footerimages/scigov77.png" alt="science.gov" height="31" width="98"></a> <a href="http://worldwidescience.org"><img src="https://www.osti.gov/images/footerimages/wws82.png" alt="WorldWideScience.org" height="31" width="90"></a> </div> </div> </div> </div> </div> <p><br></p> </div><!-- container --> </body> </html>