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Sample records for laguna potrok aike

  1. Laguna Potrok Aike: palaeoenvironmental reconstruction in southern South America covering the last 50,000 years

    Science.gov (United States)

    Schaebitz, F. W.

    2012-12-01

    Laguna Potrok Aike located in the Province of Santa Cruz, southern Argentina, is one of the very few locations that are suited to reconstruct the palaeoenvironmental and climatic history of southern Patagonia outside of the Andes. The lake was drilled in the framework of the multinational ICDP (International Continental Scientific Drilling Program) project "Potrok Aike maar lake sediment archive drilling project" PASADO in 2008, when several long sediment cores to a composite depth of more than 100 m were obtained, which dates back about 50,000 years. Laguna Potrok Aike is located at about 52°S 70°W, just north of the Strait of Magellan and close to the Antarctic continent. The origin of that 100 m deep lake was a maar explosion around 770,000 years ago. Today it has an episodic inflow in the west from its catchment area stretching in SW-direction and is surrounded by Patagonian steppe formation. The first forest patches are situated about 80 km further west at the foothills of the Andes. Laguna Potrok Aike is one of the few permanent lakes in the area and was not covered by glaciers during the last ice ages. It therefore offers a unique archive providing a continuous lacustrine record of the climatic and ecological history. Thus, the presentation will give a brief overview of the most important results gathered by different disciplines covering aspects of Quaternary geology, hydrology, climate reconstruction, and different dating techniques, while the focus will be on palaeobiological proxies like pollen. A continuous paleoprecipitation record for the last 50,000 years will be presented based on a pollen transfer function using the Weighted Average Partial Least Square method. Results show higher precipitation values during the Holocene than during the Last Glacial with a transition during Termination one. The paper will synthesize the locally derived palaeoecological data from Laguna Potrok Aike, compare them on a regional scale for south-eastern Patagonia and

  2. Origin and evolution of the Laguna Potrok Aike maar (Patagonia, Argentina)

    Science.gov (United States)

    Gebhardt, A. C.; de Batist, M.; Niessen, F.; Anselmetti, F. S.; Ariztegui, D.; Ohlendorf, C.; Zolitschka, B.

    2009-04-01

    Laguna Potrok Aike, a maar lake in southern-most Patagonia, is located at about 110 m a.s.l. in the Pliocene to late Quaternary Pali Aike Volcanic Field (Santa Cruz, southern Patagonia, Argentina) at about 52°S and 70°W, some 20 km north of the Strait of Magellan and approximately 90 km west of the city of Rio Gallegos. The lake is almost circular and bowl-shaped with a 100 m deep, flat plain in its central part and an approximate diameter of 3.5 km. Steep slopes separate the central plain from the lake shoulder at about 35 m water depth. At present, strong winds permanently mix the entire water column. The closed lake basin contains a sub saline water body and has only episodic inflows with the most important episodic tributary situated on the western shore. Discharge is restricted to major snowmelt events. Laguna Potrok Aike is presently located at the boundary between the Southern Hemispheric Westerlies and the Antarctic Polar Front. The sedimentary regime is thus influenced by climatic and hydrologic conditions related to the Antarctic Circumpolar Current, the Southern Hemispheric Westerlies and sporadic outbreaks of Antarctic polar air masses. Previous studies demonstrated that closed lakes in southern South America are sensitive to variations in the evaporation/precipitation ratio and have experienced drastic lake level changes in the past causing for example the desiccation of the 75 m deep Lago Cardiel during the Late Glacial. Multiproxy environmental reconstruction of the last 16 ka documents that Laguna Potrok Aike is highly sensitive to climate change. Based on an Ar/Ar age determination, the phreatomagmatic tephra that is assumed to relate to the Potrok Aike maar eruption was formed around 770 ka. Thus Laguna Potrok Aike sediments contain almost 0.8 million years of climate history spanning several past glacial-interglacial cycles making it a unique archive for non-tropical and non-polar regions of the Southern Hemisphere. In particular, variations of

  3. Patagonian and Antarctic dust as recorded in the sediments of Laguna Potrok Aike (Patagonia, Argentina)

    Science.gov (United States)

    Haberzettl, Torsten; Stopp, Annemarie; Lisé-Pronovost, Agathe; Gebhardt, Catalina; Ohlendorf, Christian; Zolitschka, Bernd; von Eynatten, Hilmar; Kleinhanns, Ilka; Pasado Science Team

    2010-05-01

    Although an increasing number of terrestrial paleoclimatic records from southern South America has been published during the last decade, these archives mostly cover the Lateglacial and/or the Holocene. Only little is known about the Patagonian climate before the Last Glacial Maximum. Here, we present a continuous, high-resolution magnetic susceptibility record for the past 48 ka from the maar lake Laguna Potrok Aike (51°58' S, 70°23' W, southern Patagonia, Argentina). Magnetic susceptibility serves as an excellent parameter for the parallelization of sediment cores all over Laguna Potrok Aike including sediment cores taken within the ICDP (International Continental Scientific Drilling Program) project PASADO (Potrok Aike maar lake Sediment Archive Drilling prOject). Additionally, magnetic susceptibility is assumed to be a proxy for dust deposition in this lake. Distinct similarities were found between the independently dated magnetic susceptibility record from Laguna Potrok Aike and the non-sea-salt calcium (nss-Ca) flux from the EPICA Dome C ice core record (75°06'S, 123°24'E) the latter being a proxy for mineral dust deposition in Antarctica [1]. Comparison of the two records and variations in grain size of the Laguna Potrok Aike sediment records indicate a relatively high aeolian activity in southern South America during the glacial period. During the Holocene climatic conditions driving sediment deposition seem to have been more variable and less dominated by wind compared to glacial times. Although the source of the dust found in Antarctic ice cores often has been attributed to Patagonia [2], we present the first evidence for contemporaneity of aeolian deposition in both the target area (Antarctica) and the major source area (Patagonia). Considering the similarities of the two records, magnetic susceptibility might yield the potential for chronological information: transfer of the ice core age model to a lacustrine sediment record. This would be important

  4. Luminescence dating of the PASADO core 5022-1D from Laguna Potrok Aike (Argentina) using IRSL signals from feldspar

    DEFF Research Database (Denmark)

    Buylaert, Jan-Pieter; Murray, A.S.; Gebhardt, A.C.;

    2013-01-01

    We have measured and tested a luminescence chronology for the PASADO core 5022-1D from the maar lake of Laguna Potrok Aike. Because of unsuitable quartz OSL characteristics, sand-sized K-feldspar extracts were chosen as a dosimeter and the dose was measured using a post-IR IRSL (pIRIR290) measure...

  5. Environmental History of Southern Patagonia Unraveled by Seismic Stratigraphy and Sediment Cores of Laguna Potrok Aike

    Science.gov (United States)

    Anselmetti, F. S.; Ariztegui, D.; de Batist, M.; Gebhardt, C.; Haberzettl, T.; Niessen, F.; Ohlendorf, C.; Zolitschka, B.

    2006-12-01

    Laguna Potrok Aike, located in Southernmost Patagonia (Argentina, 52°S) is a maar lake and likely provides the only continental Southern Patagonian archive that covers a long and continuous interval of several glacial- to-interglacial cycles. In the context of a proposed ICDP-drilling initiative (see Zolitschka et al., this session), several site surveys have been undertaken that characterize in detail the shallow subsurface of the lake. A variety of environmental changes are identified based on seismic stratigraphic analyses of a dense grid of high- resolution data. Long sediment cores recovered the material to date and calibrate these changes providing a chronology of events. The paleoenvironmental history reflects the complex interplay between variations in the hydrologic cycle, wind regime, and volcanic/tectonic activity. Laguna Potrok Aike is the largest and deepest lake (maximum depth 100 m) in the Pali Aike Volcanic Field. It is steeply-rimmed, circular in shape with a diameter of 3 km and surrounded subaerially by a series of paleoshorelines, reflecting its sensitivity to changes in the evaporation/precipitation ratio. Seismic subsurface data indicate a basinwide erosional unconformity, that consistently occurs on the shoulder of the lake down to a depth of -35 m (below modern lake level) marking the lowest lake level during the Late Glacial-to-Holocene times. Cores that penetrate this unconformity comprise MIS3-dated sediments (45 ka) 3.5 m below the unconformity that were deposited during high lake levels. These cores also provide an age of 6800 cal BP for the transgressional sediments burying the unconformity. This middle Holocene transgression following the maximum lake level lowstand marks the onset of a stepwise increase in moisture, as shown by a series of buried paleoshorelines that were formed during at least five lake level stillstands between the depths of -32 and -12 m. No indications point towards an intermittent lake level lowering, so that

  6. Origin and evolution of the Laguna Potrok Aike maar (Southern Patagonia, Argentina) as revealed by seismic data

    Science.gov (United States)

    Gebhardt, C.; de Batist, M. A.; Niessen, F.; Anselmetti, F.; Ariztegui, D.; Haberzettl, T.; Ohlendorf, C.; Zolitschka, B.

    2009-12-01

    Seismic reflection and refraction data provide insights into the sedimentary infill and the underlying volcanic structure of Laguna Potrok Aike, a maar lake situated in the Pali Aike Volcanic Field, Southern Patagonia. The lake has a diameter of ~3.5 km, a maximum water depth of ~100 m and a presumed age of ~770 ka. Its sedimentary regime is influenced by climatic and hydrologic conditions related to the Antarctic Circumpolar Current, the Southern Hemispheric Westerlies and sporadic outbreaks of Antarctic polar air masses. Multiproxy environmental reconstructions of the last 16 ka document that this terminal lake is highly sensitive to climate change. Laguna Potrok Aike has recently become a major focus of the International Continental Scientific Drilling Program and was drilled down to 100 m below lake floor in late 2008 within the PASADO project. The sediments are likely to contain a continental record spanning the last ca. 80 kyrs unique in the South American realm. Seismic reflection data show relatively undisturbed, stratified lacustrine sediments at least in the upper ~100 m of the sedimentary infill but are obscured possibly by gas and/or coarser material in larger areas. A model calculated from seismic refraction data reveals a funnel-shaped structure embedded in the sandstone rocks of the surrounding Santa Cruz Formation. This funnel structure is filled by lacustrine sediments of up to 370 m in thickness. These can be separated into two distinct subunits with low acoustic velocities of 1500-1800 m s-1 in the upper subunit pointing at unconsolidated lacustrine muds, and enhanced velocities of 2000-2350 m s-1 in the lower subunit. Below these lacustrine sediments, a unit of probably volcanoclastic origin is observed (>2400 m s-1). This sedimentary succession is well comparable to other well-studied sequences (e.g. Messel and Baruth maars, Germany), confirming phreatomagmatic maar explosions as the origin of Laguna Potrok Aike.

  7. The Laguna Potrok Aike Scientific Drilling Project PASADO (ICDP Expedition 5022

    Directory of Open Access Journals (Sweden)

    Pierre Francus

    2009-09-01

    Full Text Available In the Southern Hemisphere long, continuous, and high-resolution series of terrestrial paleoclimatic data are scarce, and they are only slowly emerging. Globally speaking, the most extreme oceanic character is encountered between 40°S and 60°S (Fig. 1. In this latitudinal belt ninety-eight percent of water is juxtaposed to only two percent of land—Patagonia and a few sub-Antarctic islands. Therefore, records from Patagonia are a key to a better evaluation ofinter-hemispheric linkages and differences in the climate system, especially as the Southern Ocean plays a key role for a proper understanding of the global climate system (Kaiser et al., 2007. Moreover, this region—close to the Andean volcanic chain—is one of the source regions for southern hemispheric dust. It is also subject to shifts in polar to mid-latitude pressure fields and precipitation regimes related to the Southern Hemispheric Westerlies and the Antarctic Oscillation. Patagonia thus potentially provides uniqueterrestrial records of variations in (1 climate, (2 hydrology, (3 erosion and deposition of atmospheric dust, and (4 volcanic activity. Additionally, links can be established to ice cores from Antarctica and to marine records from the South Atlantic where dust and tephra of Patagonian provenance have been deposited (Ackert, 2009; Narcisi et al., 2005; Sugden et al., 2009. For southernmost South America most lake sediments extend in time not beyond theLate-Glacial. However, Laguna Potrok Aike (Fig. 1 is older than the numerous Patagonian glacial lakes and offers the opportunity for volcanological studies.

  8. New Constraints on Maar Geometry and Sedimentary Fill of Laguna Potrok Aike, Southern Patagonia

    Science.gov (United States)

    Gebhardt, C. A.; Niessen, F.; Anselmetti, F.; Ariztegui, D.; de Batist, M.; Haberzettl, T.; Ohlendorf, C.; Zolitschka, B.

    2007-12-01

    Laguna Potrok Aike is located in Southern Patagonia, Argentina, at 52°S and 70°W. The maar lake has a diameter of 3.5 km and is almost circular and bowl-shaped with a deep, flat plain (100 m water depth) in its central part. Steep flanks separate the lake shoulders at 15 to 35 m water depth from the central plain. The lake is situated in the Pali Aike Volcanic Field at the present boundary between the Southern Hemispheric Westerlies and the Antarctic Polar Front. Its lake level is highly susceptible to changes in the Antarctic Circumpolar Current that controls the regional precipitation patterns. Its sedimentary infill possibly contains a long and continuous record of several glacial and interglacial cycles, which is unique in the southern South American realm. Two major stratigraphic units (I and II) were distinguished in the seismic sections. Unit I consists of the lacustrine infill and was further subdivided into Sub-units I-a and I-b on the lake shoulders and I-ab, I-c, and I-d in the central basin. Sub-units I-a and I-b on the lake shoulders are separated by a major unconformity and contain several paleoshoreline structures formed during a step-wise transgression after a lake level lowstand of approx. 35 m below the present lake level. In the central basin, Sub-units I-a and I-b are merged into Sub-unit I-ab, not being separated by any unconformity. Pelagic sedimentation dominates in the northern and central parts, whereas mass movement deposits were found in the southern, western and eastern parts close to the steep diatreme flanks. The boundary between I-ab and I-c is non-erosive with I-ab forming downlaps onto I-c from the eastern and western parts of the lake, pointing at a significantly lower lake level during its accumulation. Sub-unit I-d shows similar characteristics as I-ab. The bedrock (Unit II) that forms the steep diatreme flanks consists of the well-layered sandstones found in the lake surroundings.

  9. Vegetation history in southern Patagonia: first palynological results of the ICDP lake drilling project at Laguna Potrok Aike, Argentina

    Science.gov (United States)

    Schäbitz, Frank; Michael, Wille

    2010-05-01

    Laguna Potrok Aike located in southern Argentina is one of the very few locations that are suited to reconstruct the paleoenvironmental and climatic history of southern Patagonia. In the framework of the multinational ICDP deep drilling project PASADO several long sediment cores to a composite depth of more than 100 m were obtained. Here we present first results of pollen analyses from sediment material of the core catcher. Absolute time control is not yet available. Pollen spectra with a spatial resolution of three meters show that Laguna Potrok Aike was always surrounded by Patagonian Steppe vegetation. However, the species composition underwent some marked proportional changes through time. The uppermost pollen spectra show a high contribution of Andean forest and charcoal particles as it can be expected for Holocene times and the ending last glacial. The middle part shows no forest and relatively high amounts of pollen from steppe plants indicating cold and dry full glacial conditions. The lowermost samples are characterized by a significantly different species composition as steppe plants like Asteraceae, Caryophyllaceae, Ericaceae and Ephedra became more frequent. In combination with higher charcoal amounts and an algal species composition comparable to Holocene times we suggest that conditions during the formation of sediments at the base of the record were more humid and/or warmer causing a higher fuel availability for charcoal production compared to full glacial times.

  10. Characterizing the eolian sediment component in the lacustrine record of Laguna Potrok Aike (southeastern Patagonia)

    Science.gov (United States)

    Ohlendorf, C.; Gebhardt, C.

    2013-12-01

    Southern South America with its extended dry areas was one of the major sources for dust in the higher latitudes of the southern hemisphere during the last Glacial, as was deduced from fingerprinting of dust particles found in Antarctic ice cores. The amount of dust that was mobilized is mostly related to strength and latitudinal position of the Southern Hemisphere Westerly Winds (SWW). How exactly SWW shifted between glacial and interglacial times and what consequences such shifts had for ocean and atmospheric circulation changes during the last deglaciation is currently under debate. Laguna Potrok Aike (PTA) as a lake situated in the middle of the source area of dust offers the opportunity to arrive at a better understanding of past SWW changes and their associated consequences for dust transport. For this task, a sediment record of the past ~51 ka is available from a deep drilling campaign (PASADO). From this 106 m long profile, 76 samples representing the different lithologies of the sediment sequence were selected to characterize an eolian sediment component. Prior to sampling of the respective core intervals, magnetic susceptibility was measured and the element composition was determined by XRF-scanning on fresh, undisturbed sediment. After sampling and freeze drying, physical, chemical and mineralogical sediment properties were determined before and after separation of each sample into six grainsize classes for each fraction separately. SEM techniques were used to verify the eolian origin of grains. The aim of this approach is to isolate an exploitable fingerprint of the eolian sediment component in terms of their grain size, physical properties, geochemistry and mineralogy. Thereby, the challenging aspect is that such a fingerprint should be based on high-resolution down-core scanning techniques, so time-consuming techniques such as grain-size measurements by laser detection can be avoided. A first evaluation of the dataset indicates that magnetic

  11. PASADO - ICDP Deep Drilling at Laguna Potrok Aike (Argentina): A 50 ka Record of Increasing Environmental Dynamics

    Science.gov (United States)

    Zolitschka, Bernd; Anselmetti, Flavio; Ariztegui, Daniel; Francus, Pierre; Gebhardt, Catalina; Kliem, Annette Hahn Pierre; Lücke, Andreas; Ohlendorf, Christian; Schäbitz, Frank; Wastegard, Stefan

    2010-05-01

    Laguna Potrok Aike, located in the South-Patagonian province of Santa Cruz (52°58'S, 70°23'W), was formed by a volcanic (maar) eruption in the late Quaternary Pali Aike Volcanic Field several hundred thousand years ago. This archive holds a unique record of paleoclimatic and paleoecological variability from a region sensitive to variations in southern hemispheric wind and pressure systems, which provide a significant cornerstone for the understanding of the entire global climate system. Moreover, Laguna Potrok Aike is close to many active volcanoes allowing a better understanding of the history of volcanism in the Pali Aike Volcanic Field as well as in the Andean mountain chain, the latter located in a distance of less than 150 km to the west. Finally, Patagonia is the source region of eolian dust blown from the South American continent into the South Atlantic and onto the Antarctic ice sheet. The currently ongoing global climate change, the thread of volcanic hazards as well as of regional dust storms are of increasing socio-economic relevance and thus challenging scientific themes that are tackled for southernmost South America with an interdisciplinary research approach in the framework of the ICDP-funded "Potrok Aike Maar Lake Sediment Archive Drilling Project" (PASADO). Using the GLAD800 drilling platform seven holes were drilled in the southern spring of 2008. A total of 510 m of lacustrine sediments were recovered by an international scientific team from the central 100 m deep basin with an excellent core recovery rate of 94.4%. The reference profile with a composite depth of 106 m consists of undisturbed laminated and sand-layered lacustrine silts with an increasing number of coarse gravel layers, turbidites and homogenites with depth. Below 80 m composite depth two mass-movement deposits (10 m and 5 m in thickness) are recorded. These deposits show tilted and distorted layers as well as nodules of fine-grained sediments and randomly distributed gravel

  12. Deep Drilling at Laguna Potrok Aike, Argentina: Recovery of a Paleoclimate Record for the Last Glacial from the Southern Hemisphere

    Science.gov (United States)

    Zolitschka, B.; Anselmetti, F.; Ariztegui, D.; Corbella, H.; Francus, P.; Gebhardt, C.; Hahn, A.; Kliem, P.; Lücke, A.; Ohlendorf, C.; Schäbitz, F.

    2009-12-01

    Laguna Potrok Aike, located in the South-Patagonian province of Santa Cruz (52°58’S, 70°23’W), was formed 770 ka ago by a volcanic (maar) eruption. Within the framework of the ICDP-funded project PASADO two sites were drilled from September to November 2008 using the GLAD800 drilling platform. A total of 513 m of lacustrine sediments were recovered from the central deep basin by an international team. The sediments hold a unique record of paleoclimatic and paleoecological variability from a region sensitive to variations in southern hemispheric wind and pressure systems and thus significant for the understanding of the global climate system. Moreover, Laguna Potrok Aike is close to many active volcanoes allowing a better understanding of the history of volcanism in the Pali Aike Volcanic Field and in the nearby Andean mountain chain. These challenging scientific themes need to be tackled in a global context as both are of increasing socio-economic relevance. On-site core logging based on magnetic susceptibility data documents an excellent correlation between the quadruplicate holes drilled at Site 1 and between the triplicate holes recovered from Site 2. Also, correlation between both sites located 700 m apart from each other is feasible. After splitting the cores in the lab, a reference profile was established down to a composite depth of 107 m for the replicate cores from Site 2. Sediments consist of laminated and sand-layered lacustrine silts with an increasing number of turbidites and homogenites with depth. Below 80 m composite depth two mass movement deposits (10 m and 5 m in thickness) are recorded. These deposits show tilted and distorted layers as well as nodules of fine grained sediments and randomly distributed gravel. Such features indicate an increased slump activity probably related to lake level fluctuations or seismicity. Also with depth coarse gravel layers are present and point to changes in hydrological conditions in the catchment area

  13. Linking microbial assemblages to paleoenvironmental conditions from the Holocene and Last Glacial Maximum times in Laguna Potrok Aike sediments, Argentina

    Science.gov (United States)

    Vuillemin, Aurele; Ariztegui, Daniel; Leavitt, Peter R.; Bunting, Lynda

    2014-05-01

    Laguna Potrok Aike is a closed basin located in the southern hemisphere's mid-latitudes (52°S) where paleoenvironmental conditions were recorded as temporal sedimentary sequences resulting from variations in the regional hydrological regime and geology of the catchment. The interpretation of the limnogeological multiproxy record developed during the ICDP-PASADO project allowed the identification of contrasting time windows associated with the fluctuations of Southern Westerly Winds. In the framework of this project, a 100-m-long core was also dedicated to a detailed geomicrobiological study which aimed at a thorough investigation of the lacustrine subsurface biosphere. Indeed, aquatic sediments do not only record past climatic conditions, but also provide a wide range of ecological niches for microbes. In this context, the influence of environmental features upon microbial development and survival remained still unexplored for the deep lacustrine realm. Therefore, we investigated living microbes throughout the sedimentary sequence using in situ ATP assays and DAPI cell count. These results, compiled with pore water analysis, SEM microscopy of authigenic concretions and methane and fatty acid biogeochemistry, provided evidence for a sustained microbial activity in deep sediments and pinpointed the substantial role of microbial processes in modifying initial organic and mineral fractions. Finally, because the genetic material associated with microorganisms can be preserved in sediments over millennia, we extracted environmental DNA from Laguna Potrok Aike sediments and established 16S rRNA bacterial and archaeal clone libraries to better define the use of DNA-based techniques in reconstructing past environments. We focused on two sedimentary horizons both displaying in situ microbial activity, respectively corresponding to the Holocene and Last Glacial Maximum periods. Sequences recovered from the productive Holocene record revealed a microbial community adapted to

  14. High-resolution Late Pleistocene paleomagnetic secular variation record from Laguna Potrok Aike, Southern Patagonia (Argentina): preliminary results from the ICDP-PASADO drilling

    Science.gov (United States)

    Lisé-Pronovost, Agathe; St-Onge, Guillaume; Haberzettl, Torsten; Pasado Science Team

    2010-05-01

    High-resolution paleomagnetic reconstructions from sedimentary sequences are scarce in the Southern Hemisphere. Therefore, the millennial- to centennial-scale variability of the geomagnetic field is under-represented in the Southern Hemisphere relative to the Northern Hemisphere and the possible global nature of that variability cannot be assessed. Here we present the first high-resolution Late Pleistocene paleomagnetic secular variation (PSV) reconstruction from the continental archive Laguna Potrok Aike south of 42°S in South America. Laguna Potrok Aike (51°58'S, 70°23'W) is a maar lake located in the Pali Aike Volcanic Field in southern Patagonia (Argentina). Previous studies revealed very high Holocene sedimentation rates (> 100 cm/ka) in the center of the lake. During the austral spring 2008, the multi-national Potrok Aike maar lake Sediment Archive Drilling prOject (PASADO) science team drilled two ~100 m holes under the framework of the International Continental scientific Drilling Program (ICDP). A preliminary Holocene age model based on comparison of magnetic susceptibility data from the PASADO core with the well-dated (radiocarbon- and tephra-based chronology) core located nearby in the center of the lake (PTA03-12) indicates a continuous deposition of ~19 m of lacustrine sediments since the last 16 ka cal. BP. Hysteresis measurements using an alternating gradient force magnetometer indicate a magnetic assemblage dominated by magnetite grains in the pseudo-single domain range. Principal component analysis (PCA) inclination and declination profiles were constructed from the stepwise alternating field demagnetization of the natural remanent magnetization (NRM) measured on u-channels at 1 cm intervals using a 2G Enterprises cryogenic magnetometer. The PCA inclinations vary around the expected geocentric axial dipole (GAD) inclination for the latitude of the coring site and the maximum angular deviation (MAD) values are generally lower than 5°, indicating

  15. Frequency of event deposits reflecting glacial/interglacial conditions during the last ca. 50,000 years in the south Patagonian maar lake Laguna Potrok Aike, Argentina

    Science.gov (United States)

    Kliem, Pierre; Hahn, Annette; Ohlendorf, Christian; Zolitschka, Bernd; Pasado Science Team

    2010-05-01

    Laguna Potrok Aike is a 100m deep maar lake located in the dry steppe of southern Patagonia. The catchment area of >200km² mainly consists of till from Bella Vista and Río Ciaike Glaciations as well as of alkali-olivine basalts of the Pali Aike Volcanic Field. Today's regional climate is affected by the Southern Hemispheric Westerlies and the rainshadow effect of the north-south striking Andean mountain chain. Since lakes are valuable terrestrial paleoclimate archives, sediments of Laguna Potrok Aike should reflect shifts of mid latitude wind and pressure fields as well as precipitation changes in southeastern South America. Aiming at the reconstruction of past climate, the deep drilling at Laguna Potrok Aike was accomplished in the framework of the ICDP project PASADO during Sept. to Dec. 2008. By correlation of three holes drilled at Site 2 ca. 700 m south of the lake's center, a composite profile of 106.09 mcd (meters composite depth) was established. According to the lowermost 14C-age of aquatic macro remains from 80.6 mcd, the entire record comprises at least 50,000 years. The initial lithological description indicates that 50.74 m (i.e. 47.8%) of the sediment record consists of remobilized sediment (turbidity currents; homogenites; ball and pillow structures, gravel layers, slumps). Such deposits are almost absent in the top 12 mcd, where laminated clays and silts dominate. Correlation with an existing piston core allows a temporal relation to the Holocene. Apart from obviously remobilized deposits Holocene sediments are distinguished from Late Glacial deposits by a lower frequency of coarse silt/fine sand layers within a silt/clay matrix. Frequency and thickness of remobilized deposits increase with sediment depth. Most reworked sections are composed of three units: (1) a dark, coarse and fining upward base overlain by (2) a homogeneous layer of silt and (3) clay capped by a relatively thin light colored clay layer. Such sequences were often described as

  16. Laguna Potrok Aike, Argentina: the first non-tropical environmental record in South America extending far beyond the Late-Glacial - a progress report

    Science.gov (United States)

    Zolitschka, B.; Anselmetti, F.; Ariztegui, D.; Corbella, H.; Francus, P.; Gebhardt, C.; Lücke, A.; Ohlendorf, C.; Schäbitz, F.; Pasado Science Team

    2009-04-01

    Within the framework of the ICDP-funded "Potrok Aike maar lake sediment archive drilling project" (PASADO) an international team of scientists carried out interdisciplinary research at the unique mid-Pleistocene (770 ka) maar lake of Laguna Potrok Aike in southern Patagonia (Province of Santa Cruz, Argentina). This lake is very sensitive to variations in southern hemispheric wind and pressure systems and thus holds a unique and continuous lacustrine record of climatic and ecological variability of global significance. Moreover, Southern Patagonia with its many active volcanoes is an ideal location to better understand the regional history of volcanism. These are two challenging geo-scientific themes that need to be tackled, especially as both of them have an increasing socio-economic relevance. Three months of drilling activities that finished last November 2008 were carried out by DOSECC from the drilling platform R/V "Kerry Kelts". More than 500 m of lacustrine sediments were recovered. This sedimentary archive will provide (1) new insights into the processes of regional back arc volcanism within the Pali Aike Volcanic Field itself as well as the more distant explosive volcanism of the Andean mountain chains; and, (2) high-resolution (decadal) quantitative climate and environmental reconstructions supported by multiple dating and stratigraphic correlations. Marine - ice core - terrestrial linkages will be emphasized as well as the incorporation of results from global climate modelling simulations for the last ca. 100 ka. The two drilled sites in the central deep basin of Laguna Potrok Aike have been selected based on four seismic surveys carried out between 2003 and 2005. Sediments were recovered at both drilled sites down to a subbottom depth of slightly more than 100 m using the GLAD800 drill rig with the hydraulic piston corer tool (HPC) at water depths varying between 95 and 100 m. The total core recovery is 94%. On-site core logging with the multi sensor

  17. Modern and subrecent spatial distribution and characteristics of sediment infill controlled by internal depositional dynamics, Laguna Potrok Aike (southern Patagonia, Argentina)

    Science.gov (United States)

    Kastner, S.; Ohlendorf, C.; Haberzettl, T.; Lücke, A.; Maidana, N. I.; Mayr, C.; Schäbitz, F.; Zolitschka, B.

    2009-04-01

    Situated in the dry steppe environment of south-eastern Patagonia the 100 m deep and max. 770 ka old maar lake Laguna Potrok Aike (51°58'S, 70°23'W) has a high potential as a palaeolimnological key site for the reconstruction of terrestrial palaeoclimate conditions. As this area is sensitive to variations in southern hemispheric wind and pressure systems the lake holds a unique lacustrine record of palaeoclimatic and palaeoecological variability. Depositional changes inferred from the lacustrine sediment sequence as well as subaerial and subaquatic lake level terraces provide detailed information about the water budget of the lake related to the variability of the Southern Hemispheric Westerlies. For this reason the lake was chosen as an ICDP drilling site in 2008 within the "Potrok Aike maar lake sediment archive drilling project" (PASADO). Based on high resolution multi-proxy investigations of the last 16,000 years carried out on a 18.9 m long sediment record (Haberzettl et al., 2007; Mayr et al., 2009; Wille et al., 2007) this study focuses on the understanding of internal depositional dynamics which control the characteristics and spatial distribution of the sediment infill of this lake. Furthermore, it provides information improving the accuracy of the interpretation of the long sediment record recovered within the PASADO project. A survey of the spatial sediment distribution was carried out in 2005 using 46 gravity cores of up to 49 cm length covering a range of water depths from 9 to 100 m. All 46 cores were scanned with X-ray fluorescence technique and for magnetic susceptibility with up to 1 mm spatial resolution. Using Ca and Ti as well as magnetic susceptibility data the cores were correlated and linked to the established age model (Haberzettl et al., 2005). As these parameters vary considerably and not consistently within the suite of littoral cores, a correlation prior to the 2005 sediment surface is solely based on cores from water depths exceeding

  18. Magnetic parameters and their palaeoclimatic implications—the sediment record of the last 15 500 cal. BP from Laguna Potrok Aike (Argentina)

    Science.gov (United States)

    Irurzun, M. A.; Orgeira, M. J.; Gogorza, C. S. G.; Sinito, A. M.; Compagnucci, R.; Zolitschka, B.

    2014-08-01

    Lake sediments are excellent sources of palaeoenvironmental and palaeoclimatic information because they provide continuous and high-resolution records. South America is of particular interest because it is the only landmass that stretches southward into the Pacific and Atlantic Oceans towards Antarctica. The aim of this study is to explore the relationship of magnetic parameters with elemental and palaeobiological data of Laguna Potrok Aike to develop a model of lake-level changes and related hydrological and climatic fluctuations. Magnetic measurements were performed on subsamples from 15 500 cal. BP to the present, and associated rock magnetic parameters were calculated to infer magnetic mineralogy, concentration and grain size. According to the model, parameters dependent on magnetic concentration and grain size are directly related to lake-level changes. During dry periods, the remanent coercivity displays high values, whereas the proportion of magnetite is relatively low. Low percentages of greigite are observed, indicating that the water of the lake was stratified at least four times during the studied period, at approximately 10 300, 8900, 8500 and 8300 cal. BP. The preservation of greigite by inhibiting its complete transformation into pyrite is associated with a rapid burial that occurs with high sedimentation rates. Thermal stratification could be caused by a slight cooling in the area triggered by a weakening of the Westerlies and/or low activity of the sun, sum to the effect of a flood of melt water in the North Atlantic.

  19. Changements climatiques et variations du champ magnetique terrestre dans le sud de la Patagonie (Argentine) depuis 51 200 ans reconstitues a partir des proprietes magnetiques des sediments du lac Laguna Potrok Aike

    Science.gov (United States)

    Lise-Pronovost, Agathe

    Rock magnetism is influenced by climate and by the Earth's magnetic field. The goal of this thesis is to use the rock magnetic properties of the long sedimentary sequence from the lake Laguna Potrok Aike (106 m, 51200 cal BP) to derive paleomagnetic and paleoclimatic records in a key area of the Southern Hemisphere that is poorly documented. Laguna Potrok Aike (52°S, 70°W) is located in southeastern Patagonia (Argentina) in the path of the strong Southern Hemisphere westerly winds and in the source area of the dust deposited in Antarctica during Glacial periods. The lake geographical location is therefore ideal to reconstruct past changes in aeolian activity and climate changes in Patagonia. It is also a key location to reconstruct past changes of the geomagnetic field because the Southern Hemisphere is significantly under-documented relative to the Northern Hemisphere. In addition, the proximity of the South Atlantic Anomaly (SAA) as well as the Southern Hemisphere high flux lobes could allow identifying differences in the paleomagnetic field evolution in southern South America relative to the much more documented Northern Hemisphere. For his strong potential to provide high-resolution climatic, aeolian and paleomagnetic records beyond the last climatic transition, the maar lake Laguna Potrok Aike was drilled in the framework of the International scientific Continental Drilling Program (ICDP) for the Potrok Aike maar lake Sediment Archive Drilling prOject (PASADO). In this thesis, high-resolution rock-magnetic and physical properties are used in order to reconstruct paleoclimate and paleomagnetic records from the southernmost part of South America. In the first chapter, the full-vector paleomagnetic record (inclination, declination and relative paleointensity) derived from the sediments of Laguna Potrok Aike. A grain size influence on the relative paleointensity record (NRM/ARM) was corrected using the median destructive field of the natural remanent

  20. Climate history of the Southern Hemisphere Westerlies belt during the last glacial-interglacial transition revealed from lake water oxygen isotope reconstruction of Laguna Potrok Aike (52° S, Argentina

    Directory of Open Access Journals (Sweden)

    J. Zhu

    2014-05-01

    Full Text Available The Southern Hemisphere westerly winds (SHW play a crucial role in the large-scale ocean circulation and global carbon cycling. Accordingly, the reconstruction of its latitudinal position and intensity is essential for understanding global climatic fluctuations during the last glacial cycle. The southernmost part of the South American continent is of great importance for paleoclimate studies as the only continental mass intersecting a large part of the SHW belt. However, continuous proxy records back to the last Glacial are rare in southern Patagonia, owing to the Patagonian Ice Sheets expanding from the Andean area and the scarcity of continuous paleoclimate archives in extra-Andean Patagonia. Here, we present an oxygen isotope record from cellulose and purified bulk organic matter of aquatic moss shoots from the last glacial-interglacial transition preserved in the sediments of Laguna Potrok Aike (52° S, 70° W, a deep maar lake located in semi-arid, extra-Andean Patagonia. The highly significant correlation between oxygen isotope values of aquatic mosses and their host waters and the abundant well-preserved moss remains allow a high-resolution oxygen isotope reconstruction of lake water (δ18Olw for this lake. Long-term δ18Olw variations are mainly determined by δ18O changes of the source water of lake, surface air temperature and evaporative 18O enrichment. Under permafrost conditions during the Glacial, the groundwater may not be recharged by regional precipitation. The isolated groundwater could have had much less negative δ18O values than glacial precipitation. The less 18O depleted source water and prolonged lake water residence time caused by reduced interchange between in- and outflows could have resulted in the reconstructed glacial δ18Olw that was only ca. 3‰ lower than modern values. The significant two-step rise in reconstructed δ18Olw during the last deglaciation demonstrated the response of isotope composition of lake

  1. Environment and climate of the last 51,000 years - new insights from the Potrok Aike maar lake Sediment Archive Drilling prOject (PASADO)

    Science.gov (United States)

    Zolitschka, B.; Anselmetti, F.; Ariztegui, D.; Corbella, H.; Francus, P.; Lücke, A.; Maidana, N. I.; Ohlendorf, C.; Schäbitz, F.; Wastegård, S.

    2013-07-01

    In this introductory paper we summarize the history and achievements of the Potrok Aike maar lake Sediment Archive Drilling prOject (PASADO), an interdisciplinary project embedded in the International Continental Scientific Drilling Program (ICDP). The stringent multiproxy approach adopted in this research combined with radiocarbon and luminescence dating provided the opportunity to synthesize a large body of hydrologically relevant data from Laguna Potrok Aike (southern Patagonia, Argentina). At this site, lake level was high from 51 ka until the early Holocene when the Southern Hemisphere Westerlies (SHW) were located further to the north. At 9.3 ka cal. BP the SHW moved southward and over the latitude of the study area (52°S) causing a pronounced negative water balance with a lake level decrease of more than 50 m. Two millennia later, the SHW diminished in intensity and lake level rose to a subsequent maximum during the Little Ice Age. Since the 20th century, a strengthening of the SHW increased the evaporative stress resulting in a more negative water balance. A comparison of our data with other hydrological fluctuations at a regional scale in south-eastern Patagonia, provides new insights and also calls for better chronologies and high-resolution records of climate variability.

  2. Crater lakes of the Pali Aike Volcanic Field as key sites for paleoclimatic and paleoecological reconstructions in southern Patagonia, Argentina

    Science.gov (United States)

    Zolitschka, Bernd; Schäbitz, Frank; Lücke, Andreas; Corbella, Hugo; Ercolano, Bettina; Fey, Michael; Haberzettl, Torsten; Janssen, Stephanie; Maidana, Nora; Mayr, Christoph; Ohlendorf, Christian; Oliva, Gabriel; Paez, Marta M.; Schleser, Gerhard H.; Soto, Julio; Tiberi, Pedro; Wille, Michael

    2006-07-01

    Sedimentary records from crater lakes are of major scientific interest because they provide continuous high-resolution climatic and environmental archives. From a limnogeological survey of crater lakes performed in the Pali Aike Volcanic Field (52°S, southeastern Patagonia, Santa Cruz, Argentina), two deep crater lakes have been recognized: Laguna Potrok Aike (100 m water depth) and Laguna Azul (56 m water depth). Physico-chemical analyses of these closed lake systems demonstrate that Laguna Azul has a dimictic and thermally stratified freshwater body, whereas Laguna Potrok Aike is a subsaline polymictic lake. Both have an oxygen-rich water column from top to bottom. Laguna Potrok Aike in particular is enriched in Na, P, and Cl. The morphometry suggests that Laguna Azul is of Holocene age, whereas the potential sediment infill of Laguna Potrok Aike may comprise 250 m to a mid-Pleistocene age (770 ka). Several aerial and subaquatic lake level terraces at Laguna Potrok Aike point to lake level fluctuations triggered by prior hydrological changes. Although fine-grained sediments of both lakes are not varied, they may eventually provide a detailed terrestrial record of past environmental and climatic variations for this southern mid-latitude region.

  3. Garnet - Spinel Peridotites from Potrok Aike: An insight into the Patagonian Lithospheric Mantle

    Science.gov (United States)

    Schrott, C.; Ntaflos, T.; Bjerg, E. A.; Tschegg, C.

    2009-04-01

    The mantle-xenolith bearing hyaloclastic tephra from Potrok Aike, located 68 km SW of Río Gallegos, Argentina, provide good opportunities for studying the lithospheric mantle beneath southern Patagonia. The Potrok Aike maar belongs to the Pliocene to Holocene Pali Aike volcanic field located east of the Andean volcanic arc. The studied samples are spinel-bearing and garnet + spinel-bearing lherzolites and harzburgites. The entire suite of the studied mantle-xenoliths have protogranular to protogranular-equigranular textures. The most interesting textural features are the kelyphitic rims around both garnet and spinel, that clearly demonstrate break-down of garnet in spinel bearing xenoliths. Detailed petrographic investigations showed different degrees of kelyphitisation. Another feature is the intergranular growth of clinopyroxene, representing a late metasomatic event. No hydrous minerals were so far found in the studied xenoliths. The Potrok Aike clinopyroxenes are Cr-diopsides with Al2O3 contents ranging from 3.2 to 7.1 wt %, whereas the garnets show pyrope composition (Alm16.3Py69.3Gros13.7 Spess0.7). The spinel shows broad range of compositional variation with Cr# varying between 0.1 and 0.5. The bulk chemistry points out the fertile character of the lherzolithes (Al2O3 2.6 - 3.6 wt % and CaO 2.5 - 2.9 wt %), while the harzburgites indicate a depleted character (Al2O3 0.7 - 2.5 wt % and CaO 0.33 - 2.14 wt %). According to the REE patterns, the Protok Aike peridotites can be divided into three groups: group I, non-metasomatised peridotites with Lan/Smn from 0.76 to 0.91 and Tbn/Ybn from 0.70 to 0.71; group II, slightly metasomatised peridotites with Lan/Smn from 0.95 to 1.27 and Tbn/Ybn from 0.96 to 1.18; and group 3, metasomatised peridotites with Lan/Smn from 1.36 to 3.2 and Tbn/Ybn from 1.06 to 2.12. LA-ICP-MS analyses on clinopyroxenes from spinel-peridotites have convex upward REE patterns resembling those from the spinel-garnet-bearing peridotites

  4. Recording of climate and diagenesis through sedimentary DNA and fossil pigments at Laguna Potrok Aike, Argentina

    Science.gov (United States)

    Vuillemin, Aurèle; Ariztegui, Daniel; Leavitt, Peter R.; Bunting, Lynda; The Pasado Science Team

    2016-04-01

    Aquatic sediments record past climatic conditions while providing a wide range of ecological niches for microorganisms. In theory, benthic microbial community composition should depend on environmental features and geochemical conditions of surrounding sediments, as well as ontogeny of the subsurface environment as sediment degraded. In principle, DNA in sediments should be composed of ancient and extant microbial elements persisting at different degrees of preservation, although to date few studies have quantified the relative influence of each factor in regulating final composition of total sedimentary DNA assemblage. Here geomicrobiological and phylogenetic analyses of a Patagonian maar lake were used to indicate that the different sedimentary microbial assemblages derive from specific lacustrine regimes during defined climatic periods. Two climatic intervals (Mid-Holocene, 5 ka BP; Last Glacial Maximum, 25 ka BP) whose sediments harbored active microbial populations were sampled for a comparative environmental study based on fossil pigments and 16S rRNA gene sequences. The genetic assemblage recovered from the Holocene record revealed a microbial community displaying metabolic complementarities that allowed prolonged degradation of organic matter to methane. The series of Archaea identified throughout the Holocene record indicated an age-related stratification of these populations brought on by environmental selection during early diagenesis. These characteristics were associated with sediments resulting from endorheic lake conditions and stable pelagic regime, high evaporative stress and concomitant high algal productivity. In contrast, sulphate-reducing bacteria and lithotrophic Archaea were predominant in sediments dated from the Last Glacial Maximum, in which pelagic clays alternated with fine volcanic material characteristic of a lake level highstand and freshwater conditions, but reduced water column productivity. Comparison of sedimentary DNA composition with that of fossil pigments suggested that post-depositional diagenesis resulted in a rapid change in the initial nucleic acid composition and overprint of phototrophic communities by heterotrophic assemblages with preserved pigment compositions. Long DNA sequences (1400-900 bp) appeared to derive from intact bacterial cells, whereas short fragments (290-150 bp) reflected extracellular DNA accumulation in ancient sediments. We conclude that sedimentary DNA obtained from lacustrine deposits provides essential genetic information to complement paleoenvironmental indicators and trace post-depositional diagenetic processes over tens of millennia. However, it remains difficult to estimate the time lag between original deposition of lacustrine sediments and establishment of the final composition of the sedimentary DNA assemblage.

  5. Recording of climate and diagenesis through fossil pigments and sedimentary DNA at Laguna Potrok Aike, Argentina

    Science.gov (United States)

    Vuillemin, A.; Ariztegui, D.; Leavitt, P. R.; Bunting, L.; Pasado Science Team

    2015-11-01

    Aquatic sediments record past climatic conditions while providing a wide range of ecological niches for microorganisms. Although marine sedimentary microbial assemblages are often defined by their surrounding geochemical conditions, the influence of environmental features upon microbial development and post-depositional survival remains largely unknown in the lacustrine realm. Due to long-term microbial activity, the composition of environmental DNA can be expected to evolve with sediment depth and over time and therefore should reflect both ancient and extant microbial populations, but this hypothesis has rarely been tested using a multiproxy approach. Here geomicrobiological and phylogenetic analyses of a Patagonian maar lake were used to indicate that the different sedimentary microbial assemblages derive from specific lacustrine regimes during defined climatic periods. Two well defined climatic intervals whose sediments harboured active microbial populations and measurable ATP were sampled for a comparative environmental study based on fossil pigments and 16S rRNA gene sequences. Bacterial and archaeal 16S rRNA gene sequences recovered from the Holocene record revealed a microbial community adapted to subsaline conditions actively producing methane during organic matter degradation. These characteristics were associated with sediments resulting from endorheic lake conditions with high evaporative stress and concomitant high algal productivity. Moreover, archaeal clone libraries established throughout the Holocene record indicate an age-related stratification of these populations, consistent with a gradual use of organic substrates after deposition. In contrast, sulphate-reducing bacteria and lithotrophic Archaea were predominant in sediments dated from the Last Glacial Maximum, in which pelagic clays alternated with fine volcanic material characteristic of a lake level highstand and freshwater conditions, but reduced water column productivity. These patterns reveal that microbial assemblages identified from environmental DNA stemmed from a variety of sedimentary niches associated with climate-dependent factors (catchment inflows, water column conditions, productivity), but that initial assemblages underwent structural changes and selective preservation during early diagenesis to result in the final composition entombed in the sediments. We conclude that environmental DNA obtained from lacustrine sediments provides essential genetic information to complement paleoenvironmental indicators and trace climate change and post-depositional diagenetic processes over tens of millennia.

  6. The Laguna Potrok Aike Scientific Drilling Project PASADO (ICDP Expedition 5022)

    OpenAIRE

    Zolitschka, B.; F. Anselmetti; Ariztegui, D.; H. Corbella; P. Francus; C. Ohlendorf; F. Schäbitz; the PASADO Scientific Drilling Team

    2009-01-01

    In the Southern Hemisphere long, continuous, and high-resolution series of terrestrial paleoclimatic data are scarce, and they are only slowly emerging. Globally speaking, the most extreme oceanic character is encountered between 40°S and 60°S (Fig. 1). In this latitudinal belt ninety-eight percent of water is juxtaposed to only two percent of land—Patagonia and a few sub-Antarctic islands. Therefore, records from Patagonia are a key to a better evaluation ofinter-hemispheric linkages and dif...

  7. Magnitude, geomorphologic response and climate links of lake level oscillations at Laguna Potrok Aike, Patagonian steppe (Argentina)

    DEFF Research Database (Denmark)

    Kliem, P.; Buylaert, Jan-Pieter; Hahn, A.

    2013-01-01

    groundwater table. Frequent lake level oscillations caused deflation of emerged terraces only along the eastern shoreline due to prevailing westerly winds. Preservation of eolian deposits might be linked to relatively moist climate conditions during the past 2.5 ka.Precisely dated lake level reconstructions...

  8. Rock Magnetic Properties of Laguna Carmen (Tierra del Fuego, Argentina): Implications for Paleomagnetic Reconstruction

    Science.gov (United States)

    Gogorza, C. G.; Orgeira, M. J.; Ponce, F.; Fernández, M.; Laprida, C.; Coronato, A.

    2013-05-01

    We report preliminary results obtained from a multi-proxy analysis including paleomagnetic and rock-magnetic studies of two sediment cores of Laguna Carmen (53°40'60" S 68°19'0" W, ~83m asl) in the semiarid steppe in northern Tierra del Fuego island, Southernmost Patagonia, Argentina. Two short cores (115 cm) were sampled using a Livingstone piston corer during the 2011 southern fall. Sediments are massive green clays (115 to 70 cm depth) with irregularly spaced thin sandy strata and lens. Massive yellow clay with thin sandy strata continues up to 30 cm depth; from here up to 10 cm yellow massive clays domain. The topmost 10 cm are mixed yellow and green clays with fine sand. Measurements of intensity and directions of Natural Remanent Magnetization (NRM), magnetic susceptibility, isothermal remanent magnetization, saturation isothermal remanent magnetization (SIRM), back field and anhysteretic remanent magnetization at 100 mT (ARM100mT) were performed and several associated parameters calculated (ARM100mT/k and SIRM/ ARM100mT). Also, as a first estimate of relative magnetic grain-size variations, the median destructive field of the NRM (MDFNRM), was determined. Additionally, we present results of magnetic parameters measured with vibrating sample magnetometer (VSM). The stability of the NRM was analyzed by alternating field demagnetization. The magnetic properties have shown variable values, showing changes in both grain size and concentration of magnetic minerals. It was found that the main carrier of remanence is magnetite with the presence of hematite in very low percentages. This is the first paleomagnetic study performed in lakes located in the northern, semiarid fuegian steppe, where humid-dry cycles have been interpreted all along the Holocene from an aeolian paleosoil sequence (Orgeira et el, 2012). Comparison between paleomagnetic records of Laguna Carmen and results obtained in earlier studies carried out at Laguna Potrok Aike (Gogorza et al., 2012

  9. Relative paleointensity of the geomagnetic field over the last 4,500 years BP from sediment cores of Laguna Chaltel (Patagonia, Argentina)

    Science.gov (United States)

    Gogorza, C. G.; Irurzun, M. A.; Sinito, A. M.; Aldana, M.; Fey, M.; Ohlendorf, C.; Zolitschka, B.

    2013-05-01

    ). Our paleointensity (NRM15mT/ARM15mT) versus age curve shows good agreement with the published record from Laguna Potrok Aike, Argentina (Gogorza et al., 2012) suggesting that, in suitable sediments, paleointensity of the geomagnetic field can give a globally coherent and dominantly bipolar signal. References Aldana, M., Costanzo-Álvarez, V., Gómez, L., González, C., Díaz, M., Silva, P., Rada, M., 2011. Identification of magnetic minerals related to hydrocarbon authigenesis in Venezuelan oil fields using an alternative decomposition of isothermal remanence curves. Studia Geophysica et Geodaetica. 55, 343-358. Gogorza, C.S.G., Irurzun, M.A., Sinito, A.M., Lisé-Pronovost, A., St-Onge, G., Haberzettl, T., Ohlendorf, C., Kastner, S., Zolitschka, B., 2012. High-resolution paleomagnetic records from Laguna Potrok Aike (Patagonia, Argentina) for the last 16,000 years. Geochemistry Geophysics Geosystems. 13, Q12Z37.

  10. The Pueblo of Laguna.

    Science.gov (United States)

    Lockart, Barbetta L.

    Proximity to urban areas, a high employment rate, development of natural resources and high academic achievement are all serving to bring Laguna Pueblo to a period of rapid change on the reservation. While working to realize its potential in the areas of natural resources, commercialism and education, the Pueblo must also confront the problems of…

  11. The Maar-Diatreme System in a Mixed "Hard/Soft-Rock" Setting: an Example from the Pali Aike Volcanic Field, Argentina

    Science.gov (United States)

    Delpit, S.; Ross, P.

    2009-05-01

    The eruptive processes in diatremes remain poorly understood compared to those at other volcano types, because these processes occur at depth. Except for maar-diatreme volcanoes formed during kimberlitic eruptions, volcanologists agree that these systems are of phreatomagmatic origin. The origin of kimberlitic diatremes is more contentious, but studying non kimberlitic equivalents can be a good approach to better understand kimberlitic diatremes considering their numerous common characteristics. The geometry of maar-diatreme systems is strongly influenced by their setting in "hard-rock" or "soft-rock" environments (Lorenz, 2003, Geolines 15:72-83). Formation of maar-diatreme systems in "hard-rock" environments, like in the West Eifel Volcanic Field of Germany, is largely described in the literature but emplacement in "soft-rock" environments or mixed settings is not. In the case of "hard-rock" environments external water is provided by fracture aquifers. The eruption products are juvenile clasts and country rock fragments. The inner crater walls of the maar, and the diatreme walls, have steep slopes. In the case of "soft- rock" environments, water is contained in the sediment pores and the walls tend to be at lower angles. We recently conducted field work on maars, cinder cones and spatter rings of the Pali Aike Volcanic Field of southern Argentina as part of the Potrok Aike Maar Lake Sediment Archive Drilling Project (PASADO). These Quaternary monogenetic volcanoes were emplaced in a mixed "hard/soft-rock" environment containing young glacial sediments, basaltic lava flows, partly consolidated fluviatile sediments, and older indurated sedimentary rocks. The mixed environment of emplacement is reflected in a phreatomagmatic deposit on the inner slope of a tephra ring exposing some lapilli-tuff layers. The lapilli fraction comprises approximately 40% lithics on average (visual estimate): at least half of the fraction is composed of basaltic lava derived from a pre

  12. Laguna Atascosa Wilderness study area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a brief report on a wilderness study area located in the Laguna Atascosa National Wildlife Refuge. It discusses the history of the study area, its...

  13. The LAGUNA-LBNO Project

    Science.gov (United States)

    Avanzini, Margherita Buizza

    LAGUNA-LBNO is a Design Study funded by the European Commission to develop the design of a large and deep underground neutrino observatory; its physics program involves the study of neutrino oscillations at long baselines, the investigation of the Grand Unification of elementary forces and the detection of neutrinos from astrophysical sources. Building on the successful format and on the findings of the previous LAGUNA Design Study, LAGUNA-LBNO is more focused and is specifically considering Long Baseline Neutrino Oscillations (LBNO) with neutrino beams from CERN. Two sites, Fréjus (in France at 130 km) and Pyhäsalmi (in Finland at 2300 km), are being considered. Three different detector technologies are being studied: Water Cherenkov, Liquid Scintillator and Liquid Argon. Recently the LAGUNA-LBNO consortium has submitted an Expression of Interest for a very long baseline neutrino experiment, selecting as a first priority the option of a Liquid Argon detector at Pyhäsalmi. Detailed potential studies have been curried out for the determination of the neutrino Mass Hierarchy and the discovery of the CP-violation, using a conventional neutrino beam from the CERN SPS with a power of 750 kW.

  14. Variables Affecting Change at Laguna Elementary School.

    Science.gov (United States)

    Lockart, Barbetta L.

    After nearly 14 years of non-Indian administration, Laguna Elementary School (LES) has acquired a principal and a teacher supervisor who are not merely Indian, but of the Laguna Tribe itself, making LES the only school in the Southern Pueblos Agency with Tribal members as administrators. At first glance the situation is ideal, but there are…

  15. 2013 Tres Lagunas Post Fire, 2

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  16. 2013 Tres Lagunas Post Fire, 20

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  17. 2013 Tres Lagunas Post Fire, 7

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  18. 2013 Tres Lagunas Post Fire, 31

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    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  19. 2013 Tres Lagunas Post Fire, 15

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  20. 2013 Tres Lagunas Post Fire, 34

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    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  1. 2013 Tres Lagunas Post Fire, 10

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  2. 2013 Tres Lagunas Post Fire, 8

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    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  3. 2013 Tres Lagunas Post Fire, 22

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    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  4. 2013 Tres Lagunas Post Fire, 36

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  5. 2013 Tres Lagunas Post Fire, 23

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    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  6. 2013 Tres Lagunas Post Fire, 13

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  7. 2013 Tres Lagunas Post Fire, 3

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  8. 2013 Tres Lagunas Post Fire, 29

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  9. 2013 Tres Lagunas Post Fire, 5

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  10. 2013 Tres Lagunas Post Fire, 12

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  11. 2013 Tres Lagunas Post Fire, 35

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  12. 2013 Tres Lagunas Post Fire, 25

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  13. 2013 Tres Lagunas Post Fire, 28

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  14. 2013 Tres Lagunas Post Fire, 14

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  15. 2013 Tres Lagunas Post Fire, 18

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  16. 2013 Tres Lagunas Post Fire, 32

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  17. 2013 Tres Lagunas Post Fire, 16

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  18. 2013 Tres Lagunas Post Fire, 33

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  19. 2013 Tres Lagunas Post Fire, 19

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  20. 2013 Tres Lagunas Post Fire, 6

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  1. 2013 Tres Lagunas Post Fire, 26

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  2. 2013 Tres Lagunas Post Fire, 30

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  3. 2013 Tres Lagunas Post Fire, 4

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  4. 2013 Tres Lagunas Post Fire, 17

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  5. 2013 Tres Lagunas Post Fire, 11

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  6. 2013 Tres Lagunas Post Fire, 37

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  7. 2013 Tres Lagunas Post Fire, 1

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  8. Summary : Laguna Atascosa Wilderness study area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a very brief report on the area designated as the Laguna Atascosa Wilderness study area. Topics covered include the area's history, its land status,...

  9. Laguna Atascosa National Wildlife Refuge photographs

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a collection of photographs from Laguna Atascosa National Wildlife Refuge. The photographs show the typical terrain found within the refuge.

  10. 2013 Tres Lagunas Post Fire, 21

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  11. 2013 Tres Lagunas Post Fire, 24

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  12. 2013 Tres Lagunas Post Fire, 9

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  13. 2013 Tres Lagunas Post Fire, 27

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — USDA USFS Southwestern Region Contract # AG-8371-C-10-0011 Delivery # AG-8371-D-13-0056 DIGITAL PHOTOGRAPHY ACQUISITION, TRES LAGUNAS FIRE, NEW MEXICO Project...

  14. Synopsis of Laguna Atascosa wilderness record : Laguna Atascosa National Wildlife Refuge, Texas

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a synopsis of information regarding the wilderness status of Laguna Atascosa National Wildlife Refuge. Information covered includes a description of...

  15. Remarkable similarity in genome nucleotide sequences between the Schwarz FF-8 and AIK-C measles virus vaccine strains and apparent nucleotide differences in the phosphoprotein gene.

    Science.gov (United States)

    Ito, Chie; Ohgimoto, Shinji; Kato, Seiichi; Sharma, Luna Bhatta; Ayata, Minoru; Komase, Katsuhiro; Takeuchi, Kaoru; Ihara, Toshiaki; Ogura, Hisashi

    2011-07-01

    The Schwarz FF-8 (FF-8) and AIK-C measles virus vaccine strains are currently used for vaccination in Japan. Here, the complete genome nucleotide sequence of the FF-8 strain has been determined and its genome sequence found to be remarkably similar to that of the AIK-C strain. These two strains are differentiated only by two nucleotide differences in the phosphoprotein gene. Since the FF-8 strain does not possess the amino acid substitutions in the phospho- and fusion proteins which are responsible for the temperature-sensitivity and small syncytium formation phenotypes of the AIK-C strain, respectively, other unidentified common mechanisms likely attenuate both the FF-8 and AIK-C strains.

  16. Safety enhancement solutions Laguna Verde NPP

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-10-15

    After the event happened in the nuclear power plant of Fukushima (Japan) proposals are carried out to improve the safety systems in the nuclear power plant of Laguna Verde (Mexico), from the application of the recommendations of the US NRC, until the considerations for the renovation of the operation license. (Author)

  17. The Pali Aike Volcanic Field, Patagonia: slab-window magmatism near the tip of South America

    Science.gov (United States)

    D'Orazio, Massimo; Agostini, Samuele; Mazzarini, Francesco; Innocenti, Fabrizio; Manetti, Piero; Haller, Miguel J.; Lahsen, Alfredo

    2000-06-01

    The Pali Aike Volcanic Field (PAVF) represents the southernmost occurrence of the Cenozoic back-arc Patagonian Plateau Lavas. Its activity (Pliocene-Recent) started forming tabular lavas followed by the growth of about 470 essentially monogenetic volcanic centers (tuff-rings, maars, spatter and scoria cones). Azimuths of cone alignment, cone elongation and morphologic lineations show prevailing ENE-WSW and NW-SE trends. Erupted products consist mainly of alkaline basalt and basanite, with minor olivine basalt. PAVF rocks are quite primitive in composition (average Mg#=66, Ni=220 ppm and Cr=313 ppm) with relatively high TiO 2 (average 3.0 wt.%). Ultramafic garnet- and/or spinel-bearing xenoliths are found within PAVF volcanics. Chondrite-normalized REE patterns are significantly LREE-enriched and almost rectilinear [(La/Yb) N=10.9-21.0]. Primordial mantle-normalized distributions of incompatible trace elements, as well as Sr and Nd isotope ratios ( 87Sr/ 86Sr=0.70317-0.70339, 143Nd/ 144Nd=0.51290-0.51294), show values typical of intra-plate basalts, despite the fact that these rocks occur only 200 km east of the Andean Cordillera. Primary magmas were generated from a fertile garnet-bearing asthenospheric source at P=1.9-2.9 GPa and T=1420-1470°C. The data suggest a geodynamic model that implies sub-slab asthenosphere flow through a slab window, which started opening below this sector of South America 14 m.y. ago as a consequence of the collision of the Chile Ridge with the Chile Trench. The trailing edge of the Nazca Plate crossed below the Pali Aike area at 9-10 Ma, that is 6-5 m.y. before the onset of the volcanic activity. We hypothesize that this time delay resulted from changes in the kinematics of the South America-Scotia transform plate boundary which only allowed the Pali Aike magmas to rise after about 4 m.y.

  18. Microstructures and seismic properties of south Patagonian mantle xenoliths (Gobernador Gregores and Pali Aike)

    Science.gov (United States)

    Zaffarana, Claudia; Tommasi, Andréa; Vauchez, Alain; Grégoire, Michel

    2014-05-01

    The subcontinental lithospheric mantle evolves through time due to tectonic events and processes as static recrystallization and melt percolation. To constrain the extent of these processes in the South Patagonian subcontinental mantle lithosphere we performed a microstructural and Electron Backscattered Diffraction (EBSD) study of a suite of 35 peridotite xenoliths brought to the surface by Plio-Pleistocene alkaline volcanic rocks from Gobernador Gregores and Pali Aike. All samples show a well-developed olivine and pyroxene crystallographic preferred orientation (CPO), consistent with deformation by dislocation creep with dominant activation of [100]{0kl} in olivine. The coarse granular or tabular textures and the low density of intracrystalline deformation features indicate that deformation was followed by annealing under static conditions. The xenoliths also show microstructural evidence of multiple episodes of reactive melt percolation. Neither annealing nor melt percolation erased the olivine CPO, which has [010]-fiber, [100]-fiber and orthorhombic patterns in Pali Aike xenoliths and essentially [010]-fiber and orthorhombic patterns in Gobernador Gregores xenoliths. Seismic properties calculated based on the CPO and modal compositions are, however, rather homogeneous, with fast S-wave polarization and P-wave propagation parallel to the [100] olivine axis. The variation in the olivine CPO solely changes the minimum S-wave birefringence direction, which is normal to the foliation for axial-[010] olivine CPO. Average samples for the two localities, obtained by adding up the individual samples CPO data in a common reference frame, show, however, a ‘normal' upper mantle anisotropy with a maximum S-wave birrenfringence of ca. 5% at high angle to the both the maximum [010] and [100] axes concentrations, that is in the foliation, but normal to the lineation, and a minimum birefringence at low angle to the [100] maximum, that is parallel to the lineation.

  19. Oxidation state of Paleozoic subcontinental lithospheric mantle below the Pali Aike volcanic field in southernmost Patagonia

    Science.gov (United States)

    Wang, Jian; Hattori, Keiko H.; Li, Jianping; Stern, Charles R.

    2008-09-01

    Mantle xenoliths in the Quaternary Pali Aike alkaline basalts of southernmost Patagonia include lherzolites and harzburgites with and without garnet. The values of fO 2 for all xenoliths range from 0.33 logarithmic unit below the fayalite-magnetite-quartz buffer (FMQ - 0.33) to FMQ + 0.75, which overlap those for abyssal peridotites. The fO 2 data, together with the bulk rock and mineral compositions, suggest that the subcontinental lithospheric mantle (SCLM) below Pali Aike formed through the accretion of oceanic lithosphere. The oceanic accretion likely occurred in mid to late Paleozoic time when the southern Patagonian terrane formed along the southwest margin of Gondwana. Relict spinel inclusions in garnet suggest that garnet-facies peridotites formed from spinel-facies peridotites most likely in response to pressure increase during the accretion. Comparable fO 2 for garnet- and spinel-facies peridotites suggests that this spinel-garnet transformation was not accompanied by changes in fO 2. Metasomatism by asthenosphere-derived melt through a slab window resulted in the formation of Ti-bearing minerals, and lowering of Mg and enrichment of Ti in bulk rocks and minerals. The replacement of olivine by orthopyroxene formed orthopyroxenites in extreme cases. No significant change in fO 2 is associated with this metasomatism since similar oxidation state is observed between un-metasomatized (FMQ - 0.23 to + 0.48) and metasomatized (FMQ - 0.33 to + 0.75) samples. This is explained by the fO 2 of the asthenospheric melt (~ FMQ - 0.50) similar to the SCLM prior to the metasomatism.

  20. Recombinant Measles AIK-C Vaccine Strain Expressing the prM-E Antigen of Japanese Encephalitis Virus.

    Science.gov (United States)

    Higuchi, Akira; Toriniwa, Hiroko; Komiya, Tomoyoshi; Nakayama, Tetsuo

    2016-01-01

    An inactivated Japanese encephalitis virus (JEV) vaccine, which induces neutralizing antibodies, has been used for many years in Japan. In the present study, the JEV prM-E protein gene was cloned, inserted at the P/M junction of measles AIK-C cDNA, and an infectious virus was recovered. The JEV E protein was expressed in B95a cells infected with the recombinant virus. Cotton rats were inoculated with recombinant virus. Measles PA antibodies were detected three weeks after immunization. Neutralizing antibodies against JEV developed one week after inoculation, and EIA antibodies were detected three weeks after immunization. The measles AIK-C-based recombinant virus simultaneously induced measles and JEV immune responses, and may be a candidate for infant vaccines. Therefore, the present strategy of recombinant viruses based on a measles vaccine vector would be applicable to the platform for vaccine development.

  1. Perencanaan Kegiatan Wisata Pendidikan Dalam Kawasan Geopark Rinjani Lombok Berbasis Daya Dukung Lingkungan (Studi Daerah Aik Berik

    Directory of Open Access Journals (Sweden)

    Dwi Hardoyo

    2016-10-01

      ABSTRACT Aik Berik is a tourist destination within Geopark Rinjani Lombok. In this area there is a geological site that can be used as an education mean through educational tours for school children, but it is necessary to study environment carrying capacity so that these activities do not cause disturbance to the ecosystem as well as maintaining students activity comfort. The aim of this study was to determine Aik Berik carrying capacity that can be used to determine the best times in conducting educational tours. The method used based on modified environment carrying capacity formula calculation, the Physical Carrying Capacity (PCC,  Real Carrying Capacity (RCC and Effective Carrying Capacity (ECC. Data collected through observation/field surveys, literature, and interviews. The results showed that Aik Berik area  has value of physical carrying capacity (PCC 18.665 person/day and the Real carrying capacity (RCC 3,863 person/day. On Sunday the real carrying capacity has not been reached, approximately 19.9% of RCC or 767 person/day. Implementation of the educational tour can be done on a weekday (Monday-Friday by internship activities together or by allocating scheduled time in teaching and learning activities. Keywords:  Geopark Rinjani Lombok,  Educational Tourism, Carrying Capacity Cara sitasi: Hardoyo  ,D., Muhammad, F., dan Taruna, T. (2016. Perencanaan Kegiatan Wisata Pendidikan Dalam Kawasan Geopark Rinjani Lombok Berbasis Daya Dukung Lingkungan (Studi Daerah Aik Berik. Jurnal Ilmu Lingkungan,14(2,103-107, doi:10.14710/jil.14.2.103-107

  2. Explorando la intensidad de uso de las materias primas líticas en Pali Aike (provincia de Santa Cruz, Argentina Exploring the reduction intensity of lithic raw materials in Pali Aike (Santa Cruz province, Argentina

    Directory of Open Access Journals (Sweden)

    Judith Charlin

    2007-12-01

    Full Text Available El objetivo general del presente trabajo es evaluar la intensidad de uso a la que estuvieron sujetas las materias primas líticas utilizadas en la manufactura de artefactos en Pali Aike (sector meridional de la provincia de Santa Cruz, Argentina. La muestra analizada comprende artefactos tallados de formatización unifacial y/o con rastros complementarios que fueron recuperados en diversas localidades del campo volcánico con ocupaciones asignadas al Holoceno tardío. Diversas variables son consideradas como indicadores de la intensidad de uso o grado de reducción de las rocas, tales como la longitud de los artefactos al momento del descarte, el grado de fragmentación de los mismos, el porcentaje de corteza que conservan, la cantidad de filos y/o puntas formatizados y/o con rastros complementarios por artefacto, el ángulo de desgaste y la reactivación de los filos y/o puntas. Los resultados obtenidos señalan la existencia de diferencias en la explotación y aprovechamiento de las materias primas líticas en algunas de estas variables, en tanto que otras no ofrecen un comportamiento diferencial o simplemente no resultan sensitivas a estos factores.The main goal of this paper is to evaluate the intensity of human utilization of lithic raw materials in Pali Aike (southern Santa Cruz Province, Argentina. The sample includes artifacts unifacially retouched and/or with macroscopic edge-wear damage from different Late Holocene localities within Pali Aike. The variables considered include the length of the artifacts, fragmentation, amount of retouched and/or wear damaged edges and/or points by artifact, percentage of cortex, and resharpening. The results show that some variables point to differences in the intensity of exploitation of different raw materials, while others are not sensitive to this variation.

  3. Santa Fe Indian Camp, House 21, Richmond, California: Persistence of Identity among Laguna Pueblo Railroad Laborers, 1945-1982.

    Science.gov (United States)

    Peters, Kurt

    1995-01-01

    In 1880 the Laguna people and the predecessor of the Atchison, Topeka, and Santa Fe Railroad reached an agreement giving the railroad unhindered right-of-way through Laguna lands in exchange for Laguna employment "forever." Discusses the Laguna-railroad relationship through 1982, Laguna labor camps in California, and the persistence of…

  4. First fuel reload in Laguna Verde; Primera recarga de combustible en Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Bahena B, D

    1992-01-15

    A report containing the activities carried out during the first reload of nuclear fuel and major maintenance in the Laguna Verde nuclear reactor is presented. The previous and the specific activities are included. These last are related without including the technical considerations, data or the operation details, because these data were documented inside the registrations of the CFE, the ININ and in personal way. (Author)

  5. Laguna Atascosa National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Laguna Atascosa NWR for the next 15 years. This plan outlines the Refuge vision and...

  6. Wilderness synopsis: Laguna Atascosa National Wildlife Refuge : Wilderness study

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a synopsis of the wilderness study of the Laguna Atascosa National Wildlife Refuge. Topics covered include a description of the refuge, current...

  7. The Trail Inventory of Laguna Atascosa NWR [Cycle 2

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to create a baseline inventory of all non-motorized trails on Laguna Atascosa National Wildlife Refuge. Trails in this inventory are...

  8. Laguna Atascosa Wilderness study area : Wilderness study report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is an in-depth report containing the results of a wilderness study done of the Laguna Atascosa National Wildlife Refuge. It covers the objectives of...

  9. Letter to President [Laguna Atascosa National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a letter from the Secretary of the Interior to the President regarding the establishment of the Laguna Atascosa Wilderness area. The letter...

  10. No wilderness designation announcement [Laguna Atascosa National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a brief announcement stating that wilderness designation will not be recommended for any portion of the Laguna Atascosa National Wildlife Refuge....

  11. Laguna Atascosa National Wildlife Refuge [Land Status Map

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This map was produced by the Division of Realty to depict landownership at Laguna Atascosa National Wildlife Refuge. It was generated from rectified aerial...

  12. Statement of Bureau representative [template] [Laguna Atascosa National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a template used for the statement of the bureau representative and the public hearing for the Laguna Atascosa National Wildlife Refuge Wilderness...

  13. Laguna Cartagena National Wildlife Refuge [Land Status Map

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This map was produced by the Division of Realty to depict landownership at Laguna Cartagena National Wildlife Refuge. It was generated from rectified aerial...

  14. Laguna Cartagena National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Laguna Cartagena NWR for the next 15 years. This plan outlines the Refuge vision and...

  15. Slide presentation at wilderness public hearing : Laguna Atascosa

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a layout for the presentation to be given at the public hearing for the Laguna Atascosa National Wildlife Refuge. It details the slides that will be...

  16. Future perspectives in neutrino physics: The Laguna-LBNO case

    CERN Document Server

    Buizza Avanzini, M

    2013-01-01

    LAGUNA-LBNO is a Design Study funded by the European Commission to develop the de- sign of a deep underground neutrino observatory; its physics program involves the study of neutrino oscillations at long baselines, the investigation of the Grand Unication of elemen- tary forces and the detection of neutrinos from known and unknown astrophysical sources. Building on the successful format and on the ndings of the previous LAGUNA Design Study, LAGUNA-LBNO is more focused and is specically considering Long Baseline Neutrino Oscil- lations (LBNO) with neutrino beams from CERN. Two sites, Frejus (in France at 130 km) and Pyhasalmi (in Finland at 2300 km), are being considered. Three dierent detector technolo- gies are being studied: Water Cherenkov, Liquid Scintillator and Liquid Argon. Recently the LAGUNA-LBNO consortium has submitted an Expression of Interest for a very long baseline neutrino experiment, selecting as a rst priority the option of a Liquid Argon detector at Pyhasalmi.

  17. Tourism in Laguna (SC: Impacts and attitude.

    Directory of Open Access Journals (Sweden)

    Susana de Araujo Gastal

    2012-04-01

    Full Text Available The places by the sea, as spaces of tourism and second homes, suffer the impacts from the activity. The local population attitude, seeing these places as bonuses or otherwise, as a burden, contributes to the viability of tourism in the locality. This article aims to present a research, methodologically related to attitude construct of social psychology, conducted in Laguna, Santa Catarina, Brazil to evaluate the relationship between the community and the different impacts caused by tourism,. Data collection, using an instrument originally proposed and validated by Molero and Cuadrado (2006, allowed the analysis to forward the position of residents on the effects of tourism in the place, evaluating eight impacts factors: environmental; delinquency; everyday life; perceived importance of tourism; public services and infrastructure; intercultural; employment; and values. The results indicate that most impacts are positive on younger residents, and in the environmental, crime and social values the impact is indifferent.

  18. Metasomatic origin of garnet orthopyroxenites in the subcontinental lithospheric mantle underlying Pali Aike volcanic field, southern South America

    Science.gov (United States)

    Wang, Jian; Hattori, Keiko H.; Stern, Charles R.

    2008-11-01

    Garnet-bearing orthopyroxenites occur as both discrete xenoliths and as veinlets in peridotite xenoliths that were brought to the surface by Quaternary Pali Aike alkali basalts in the southernmost of the Patagonian plateau lava fields in southern South America. Orthopyroxenites commonly contain Ti-rich minerals and also relict grains of olivine (Ol) and clinopyroxene (Cpx) occurring as inclusions in secondary orthopyroxene (Opx). The secondary Opx contains high TiO2 (0.20-0.59 wt.%), moderate Al2O3 (2.87-5.10 wt.%) and low magnesium numbers (Mg#, 84.5-89.2) compared with Opx in garnet-bearing peridotites. This suggests that secondary Opx formed at the expense of Ol and Cpx during metasomatism by an evolved Ti-rich melt. The orthopyroxenites contain bulk-rock concentrations of Cr, Ni and platinum group elements similar to peridotites, suggesting that these metals were essentially immobile during metasomatism, and that the metasomatizing melt did not introduce these elements. Instead, the metasomatizing melt contributed alkalis, Ti, Si, Al, and S to the orthopyroxenites based on increased concentrations of these elements and mineralogy. Secondary Opx has also been documented in mantle peridotite xenoliths derived from beneath both active arcs and ancient cratons. In comparison with such Opx in these mantle samples, the secondary Opx in the Pali Aike xenoliths contains relatively high Ti and Al and low Mg. High Ti and low Mg in these samples reflect the evolved nature of the metasomatizing melt that originated from the underlying asthenospheric mantle. The type of secondary Opx, typified by these samples, may be common elsewhere in subcontinental mantle lithosphere (SCLM) affected by asthenospheric upwelling.

  19. Climate Development in Southern Santa Cruz (Argentina) During the last 1600 Years Gained from Proxies of the Salsa-Project

    Science.gov (United States)

    Schaebitz, F.; Wille, M.

    2004-12-01

    The DEKLIM project SALSA: "South Argentinean Lake Sediment Archives and Modelling" investigates lacustrine sediments with an integrated research strategy to understand quaternary ecosystem changes in space and time. SALSA studies are carried out in the Pali Aike Volcanic Field (PAVF; Santa Cruz province, southern Patagonia, Argentina). A few maar-like structures in the PAVF contain permanent lakes varying from 500 to 3700 m in diameter and exhibiting up to 100 m water depth. We will present results from short gravity cores of two different maars: Laguna Potrok Aike and Laguna Azul covering the last 1600-1300 years, respectively. An interpretation integrating the prominent sediment, isotopes and microfossil data from both lakes suggests the following climatic changes during the last 1.6 ka AD: Between the 5th and the 11th century relatively frequent moist/dry fluctuations were noticed. Between the 11th and the 20th century conditions were relatively moist except for a dry/warm period between the 13th and 15th century. The change from dry to moister conditions was dated to the 15th century. Since the middle of the 20th century climate is characterized by increasing drought.

  20. Unravelling the collapse mechanisms at a Jurassic caldera of the Chon Aike silicic LIP in Southern Patagonia (47° 15 'S, 71° 40'W), Argentina

    Science.gov (United States)

    Sruoga, P.; Japas, S.; Salani, F.; Kleiman, L.; Graffigna, M.

    2008-10-01

    La Peligrosa Caldera is located at Sierra Colorada (47° 15'S, 71° 40' W) in the Chon-Aike silicic LIP. It represents an unique window to understand the eruptive mechanisms that prevailed throughout the ignimbritic flare-up in Southern Patagonia during middle to late Jurassic times. Key pieces of lithologic and structural evidences are taken into account to reconstruct the volcanic structure.

  1. Shallow Landslide Assessment using SINMAP in Laguna, Philippines

    Science.gov (United States)

    Bonus, A. A. B.; Rabonza, M. L.; Alemania, M. K. B.; Alejandrino, I. K.; Ybanez, R. L.; Lagmay, A. M. A.

    2014-12-01

    Due to the tectonic environment and tropical climate in the Philippines, both rain-induced and seismic-induced landslides are common in the country. Numerous hazard mapping activities are regularly conducted by both academic and government institutions using various tools and software. One such software is Stability Index Mapping (SINMAP), a terrain stability mapping tool applied to shallow translational landslide phenomena controlled by shallow groundwater flow convergence. SINMAP modelling combines a slope stability model with a steady-state hydrology model to delineate areas prone to shallow landslides. DOST- Project NOAH, one of the hazard-mapping initiatives of the government, aims to map all landslide hazard in the Philippines using both computer models as well as validating ground data. Laguna, located in the island of Luzon, is one such area where mapping and modelling is conducted. SINMAP modelling of the Laguna area was run with a 5-meter Interferomteric Synthetic Aperture Radar (IFSAR) derived digital terrain model (DTM). Topographic, soil-strength and physical hydrologic parameters, which include cohesion, angle of friction, bulk density and hydraulic conductivity, were assigned to each pixel of a given DTM grid to compute for the corresponding factor of safety. The landslide hazard map generated using SINMAP shows 2% of the total land area is highly susceptible in Santa Mara, Famy, Siniloan, Pangil, Pakil and Los Baἦos Laguna and 10% is moderately susceptible in the eastern parts of Laguna. The data derived from the model is consistent with both ground validation surveys as well as landslide inventories derived from high resolution satellite imagery from 2003 to 2013. With these combined computer and on-the-ground data, it is useful in identifying no-build zone areas and in monitoring activities of the local government units and other agencies concerned. This provides a reasonable delineation of hazard zones for shallow landslide susceptible areas of

  2. Evidencias bioarqueológicas en patagonia meridional: el sitio Orejas de Burro 1 (Pali Aike, provincia de Santa Cruz Bioarchaeological Evidence In Meridional Patagonia: The Orejas De Burro 1 Site (Pali Aike, Santa Cruz Province

    Directory of Open Access Journals (Sweden)

    Gabriela L. L'Heureux

    2008-12-01

    Full Text Available En este trabajo se presentan los resultados de las excavaciones realizadas recientemente en el sitio Orejas de Burro 1, localizado en el campo volcánico Pali Aike, provincia de Santa Cruz, Argentina. En el mismo se recuperó un entierro humano compuesto por cinco individuos de diferentes edades depositados en un único evento de inhumación. La información desarrollada incluye datos estratigráficos, contextuales, bioarqueológicos e isotópicos, que contribuyen a la evaluación de temas mortuorios y biogeográficos discutidos en el Proyecto Magallania.The results from recent excavations at the Orejas de Burro 1 site (Santa Cruz Province, Argentina are presented in this paper. A human burial was recovered with the remains of five individuals from different age groups that were deposited simultaneously. Stratigraphic, contextual, bioarchaeological, and isotopic data are provided. This data contributes to discussions of mortuary behavior and human biogeography currently being developed within the Magallania Project.

  3. Laguna Verde after the extended power increase; Laguna Verde despues del aumento de potencia extendido

    Energy Technology Data Exchange (ETDEWEB)

    Herrera C, M. N.; Castaneda G, M. A.; Cardenas J, J. B.; Garcia de la C, F. M., E-mail: mitzi.herrera@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km 42.5, Alto Lucero, Veracruz (Mexico)

    2012-10-15

    The project of extended power increase that was implemented in both units of the nuclear power plant of Laguna Verde beginning with the stage feasibility evaluation in nuclear side of the facilities, that is to say the affectation of the power increase in the equipment s, systems and components of the nuclear power plant; besides the feasibility evaluation a study cost-benefit for the rehabilitated and modernization of the equipment s, systems and components of Plant Balance was realized. Once considered technical and economically feasible the project began the engineering evaluations required to carry out the licensing of the new operation conditions, as well as beginning to the elaboration of the technical specifications purchase of the equipment s, systems and components of the Plant Balance. While on one hand was carried out the administration of the licensing of the extended power increase for other was carried out the necessary engineering to make the physical changes in the conventional side of the nuclear power plant. Once concluded the constructive stage beginning the final stage of the project, the starting-up tests, operation and performance of the Units under the new operation conditions. This work describes this last stage that contains the technical base, the realized tests and the obtained results. (Author)

  4. Port Isabel (GIWW) Channel Improvements at the Queen Isabella Causeway. Laguna Madre, Texas, Navigation Improvement Project

    Science.gov (United States)

    2009-09-01

    ER D C/ CH L TR -0 9 -1 3 Port Isabel (GIWW) Channel Improvements at the Queen Isabella Causeway Laguna Madre , Texas, Navigation...Causeway Laguna Madre , Texas, Navigation Improvement Project Timothy W. Shelton, P.E. and Dennis Webb, P.E. Coastal and Hydraulics Laboratory U.S...distribution is unlimited. Prepared for U.S. Army Corps of Engineer District, Galveston Galveston, TX 77550 ERDC/CHL TR-09-13 ii Abstract: Laguna Madre is

  5. Laguna Las Tres Pascualas, Concepción

    Directory of Open Access Journals (Sweden)

    Roberto Lira Olmo

    2015-04-01

    Full Text Available La ciudad de Concepción constituye un área urbana privilegiada en relación a su asentamiento físico, ya que posee, entre otros, un paisaje natural de pocas ciudades en el mundo con sus lagunas y humedales. Entre ellas, destaca la laguna Las Tres Pascualas, la más conocida, y de mayor tamaño con una superficie de 5,3 hectáreas, emplazada en pleno casco urbano en la remozada Avenida Paicaví y próxima al nodo de Avenida Los Carrera.

  6. Recuperación urbana Laguna Las Tres Pascualas

    Directory of Open Access Journals (Sweden)

    Carolina Araya

    2015-04-01

    Full Text Available La laguna Las Tres Pascualas como hito urbano se constituye como la laguna de mayor tamaño, con una superficie de 5,3 has. y una profundidad de 5,09m, emplazada dentro del casco urbano de la ciudad. Sin embargo, a pesar de su privilegiada ubicación, se vio afectada por una paulatina y espontánea ocupación de las zonas aledañas promoviendo la consolidación de núcleos poblacionales irregulares, caracterizados por un estado permanente de marginalidad social y, lo que contribuyó a que este sistema presentara elevados índices de contaminación.

  7. Spatial distribution of cones and satellite-detected lineaments in the Pali Aike Volcanic Field (southernmost Patagonia): insights into the tectonic setting of a Neogene rift system

    Science.gov (United States)

    Mazzarini, Francesco; D'Orazio, Massimo

    2003-07-01

    The relationships between the distribution and morphometric features of eruptive structures (scoria and spatter cones, maar, tuff rings) and the fracture network were investigated in the Pliocene-Quaternary Pali Aike Volcanic Field (southernmost Patagonia, Argentina-Chile). The alkali basaltic/basanitic magmas which erupted in this area have nearly primary magma compositions and often bear mantle xenoliths; hence magma ascent from deep-seated reservoirs was probably very fast, with no significant stagnation at crustal levels. Field surveys and satellite image analysis led to the identification of up to 467 eruptive structures and four main NW-SE, NE-SW, E-W and N-S fracture systems. The spatial distribution of eruptive cones and fractures was investigated through the computation of power-law exponents ( Df) for self-similar clustering. The self-similarity of cones and fractures was defined between lower and upper cut-offs which were in turn related to the thickness of the fractured mechanical layer. The fractal character of cones and fracture distribution (clustering) in the Pali Aike Volcanic Field area was thus correlated with crustal thickness. The self-similarity of fractures was used to establish the relative chronology of the detected fracture systems. The self-similar clustering exponent is highest in the E-W and NW-SE fracture systems ( Df=1.78 and 1.77, respectively), and lowest in the N-S system ( Df=1.65). The self-similar clustering of eruptive structures is well defined ( Df=1.45). The intense volcano-tectonic activity in the Pali Aike area marks a major Pliocene-Quaternary phase in the development of the Magellan Neogene Rift System.

  8. Effects of a cattail marsh on sediment and water quality of the Laguna Atascosa National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The drainage known as the Cayo Atascosa transports irrigation return flow water through a cattail marsh and into Laguna Atascosa (Lake) located in Laguna Atascosa...

  9. Titanium and oxygen isotope diffusion in quartz-phenocrysts from a Jurassic rhyolite, Chon Aike Province (Fitz Roy, Patagonia)

    Science.gov (United States)

    Seitz, S.; Putlitz, B.; Baumgartner, L. P.; Escrig, S.; Meibom, A.; Leresche, S.; Vennemann, T. W.

    2014-12-01

    The volcanic El Quemado Complex was deposited during the breakup of Gondwana during the Middle and Late Jurassic. It is part of a large silicic igneous province, which includes the Chon Aike Province in Southern Patagonia and related rocks from the Antarctic Peninsula [1]. The Complex consists of rhyolitic and dacitic ignimbrites and air-fall tuffs, intercalated with andesitic to rhyolitic lava flows. New LA-ICPMS U/Pb-dates of zircons from the Fitz Roy area yield ages between 148 and 153Ma. No inherited zircons were found, suggesting that the temperature of 850°C calculated from zircon saturation is a minimum temperature. Lava flows are typically rich in quartz phenocrysts, which preserved magmatic trace element zoning, as revealed by cathodoluminescence (CL): light cores are surrounded by several darker and lighter zones towards the rim. The δ18O-values for quartz of between 11 to 14 ‰ are compatible with a crustal source for the magma and the SIMS analyses of phenocrysts reveal no zoning in O-isotope compositions. High-resolution Ti-profiles were obtained by NanoSIMS with a beam size of ~200 nm and a minimum step size of ~120 nm. Several lines perpendicular to the magmatic zoning of the quartz-phenocrysts were measured. The profiles show sharp changes in the 48Ti/29Si-ratio over a distance of 5 μm, which correlate with CL-intensity changes. The profiles can be used for diffusion chronometry. The distances obtained from NanoSIMS profiles were used to calculate maximum diffusional relaxation times. Assuming a step function as initial condition and extrusion temperatures from zircon saturation of 850°C, we obtain a maximum residence time for the quartz-phenocrysts of 3.5 years. [1] Pankhurst R.J., Riley T.R., Fanning C.M., Kelley S.P., 2000. J. Pet., 41, 605-625.

  10. Relationship between Bajo Pobre and Chon Aike formations (Deseado Massif, Patagonia, Argentina):a melt inclusions study

    Science.gov (United States)

    Busà, T.; Bellieni, G.; Fernandez, R.; Hecheveste, H.; Piccirillo, E. M.

    2003-04-01

    The Deseado Massif covers the centre-east of the Santa Cruz Province, in the extra-Andean Patagonia. Although the Deseado Massif is mainly composed of silicic volcanic rocks (Chon Aike Formation, CA; 151.5 ±0.5 - 177.8 ±0.4 Ma), mafic and intermediate volcanites (Bajo Pobre Formation, BP; 152.7 ±0.5 and 164 ±0.3 Ma) outcrop largely in the central part of the Massif. In this paper quarz-trapped melt inclusions (rhyolitic in composition) from selected samples of the BP and the CA are analysed. On the basis of major elements content, for BP the sequence from andesite (BP whole rock) to ryholite (trapped as inclusions in quartz) can be modelled by simple fractional crystallisation of ortho- and clinopyroxene, plagioclase, quartz and apatite. As regards trace elements, a good calculated/measured ratio (around 1 ±0.2) is obtained assuming only a relatively high apatite fractionation. Since the apatite fractionation amount is not acceptable for major elements, the evolution of BP Formation cannot be modelled by a simple process of fractional crystallisation, and a contamination process probably occurred. The sequence from BP to CA cannot be modelled by fractional crystallisation. 30% batch melting of BP andesite (BP whole rock) produces a magma from which the CA ryholites (trapped as inclusions in quartz) can be obtained by Rayleigh fractional crystallisation of ortho- and clinopyroxene, plagioclase, magnetite, quartz, apatite and small amounts of zircon and minor allanite. Since the latter one was not observed in the analysed sample, a contamination process during magma evolution cannot be completely excluded. Finally, on the basis of the different trace elements concentration (Nb anomaly, different content in LILE, B/Be and B/Nb), it is possible to suppose that, at the time of the BP and CA emplacement, a changing in the tectonic setting, from subduction to a lithospheric extension, was active.

  11. 75 FR 74073 - Laguna Atascosa National Wildlife Refuge, Cameron and Willacy Counties, TX; Final Comprehensive...

    Science.gov (United States)

    2010-11-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Fish and Wildlife Service Laguna Atascosa National Wildlife Refuge, Cameron and Willacy Counties, TX... Register July 19, 2004 (69 FR 43010). Laguna Atascosa NWR is located in Cameron and Willacy Counties, Texas...

  12. Laguna Verde BWRs operational experience: steady-state fuel performance

    Energy Technology Data Exchange (ETDEWEB)

    Cuevas V, G. F.; Bravo S, J. M. [Global Nuclear Fuel - Americas, 3901 Castle Hayne Road, Wilmington, 28401 North Carolina (United States); Casillas, J. L., E-mail: gabriel.cuevas-vivas@gnf.co [General Electric Hitachi Nuclear Energy, 1989 Little Orchard St. Romm 239, San Jose, 95125 California (United States)

    2010-10-15

    The two BWR at Laguna Verde nuclear power station are finishing 21 and 15 years of continuous successful operation as of 2010. During Unit 1 and 2 commercial operations only Ge/GNF fuel designs have been employed; fuel lattice designs 8 x 8 and 10 x 10 were used at the reactor, with an original licensed thermal power (OLTP: 1931 MWt) and the reactor's first power up-rates of 5%. GNF fuel will be also used for the second EPU to reach 120% of OLTP in the near future. Thermal and gamma traversing in-core probes (Tip) are used for power monitoring purposes along with the Ge (now GNF-A) core monitoring system, 3-dimensional Monicore{sup TM}. GNF-A has also participated by preparing the core management plan that is regularly fine-tuned in collaboration with Comision Federal de Electricidad (CFE owner of the Laguna Verde reactors). For determination of thermal margins and eigenvalue prediction, GNF-A employs the NRC-licensed steady-state core simulator PANAC11. Tip comparisons are routinely used to adapt power distributions for a better thermal margin calculation. Over the years, several challenges have appeared in the near and long term fuel management planning such as increasing cycle length, optimization of the thermal margins, rated power increase, etc. Each challenge has been successfully overcome via operational strategy, code improvements and better fuel designs. This paper summarizes Laguna Verde Unit 1 and 2 steady-state performance from initial commercial operation, with a discussion of the nuclear and thermal-hydraulic design features, as well as of the operational strategies that set and interesting benchmark for future fuel applications, code development and operation of the BWRs. (Author)

  13. Antineutrino Flux from the Laguna Verde Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    Marisol Chavez-Estrada

    2015-01-01

    Full Text Available We present a calculation of the antineutrino flux produced by the reactors at the Laguna Verde Nuclear Power Plant in México, based on the antineutrino spectra produced in the decay chains of the fission fragments of the main isotopes in the reactor core, and their fission rates, which have been calculated using the DRAGON simulation code. We also present an estimate of the number of expected events in a detector made of plastic scintillator with a mass of 1 ton, at 100 m from the reactor cores.

  14. Quaternary pollen record from laguna de tagua tagua, chile.

    Science.gov (United States)

    Heusser, C J

    1983-03-25

    Pollen of southern beech and podocarp at Laguna de Tagua Tagua during the late Pleistocene indicates that cooler and more humid intervals were a feature of Ice Age climate at this subtropical latitude in Chile. The influence of the southern westerlies may have been greater at this time, and the effect of the Pacific anticyclone was apparently weakened. The climate today, wet in winter and dry in summer, supports broad sclerophyll vegetation that developed during the Holocene with the arrival of paleo-Indians and the extinction of mastodon and horse.

  15. Antineutrino flux from the Laguna Verde Nuclear Power Plant

    CERN Document Server

    Chavez-Estrada, Marisol

    2015-01-01

    We present a a calculation of the antineutrino flux produced by the reactors at the Laguna Verde Nuclear Power Plant in M\\'exico, based on the antineutrino spectra produced in the decay chains of the fission fragments of the main isotopes in the reactor core, and their fission rates, that have been calculated using the DRAGON simulation code. We also present an estimate of the number of expected events in a detector made of plastic scintillator with a mass of 1 ton, at 100 m from the reactor cores.

  16. High-$\\gamma$ Beta Beams within the LAGUNA design study

    CERN Document Server

    Orme, Christopher

    2010-01-01

    Within the LAGUNA design study, seven candidate sites are being assessed for their feasibility to host a next-generation, very large neutrino observatory. Such a detector will be expected to feature within a future European accelerator neutrino programme (Superbeam or Beta Beam), and hence the distance from CERN is of critical importance. In this article, the focus is a $^{18}$Ne and $^{6}$He Beta Beam sourced at CERN and directed towards a 50 kton Liquid Argon detector located at the LAGUNA sites: Slanic (L=1570 km) and Pyh\\"{a}salmi (L=2300 km). To improve sensitivity to the neutrino mass ordering, these baselines are then combined with a concurrent run with the same flux directed towards a large Water \\v{C}erenkov detector located at Canfranc (L=650 km). This degeneracy breaking combination is shown to provide comparable physics reach to the conservative Magic Baseline Beta Beam proposals. For $^{18}$Ne ions boosted to $\\gamma=570$ and $^{6}$He ions boosted to $\\gamma=350$, the correct mass ordering can be...

  17. Gamma thermometer longevity test: Laguna Verde 2 instruments recent performance

    Energy Technology Data Exchange (ETDEWEB)

    Cuevas V, G. [Global Nuclear Fuel, Americas, 3901 Castle Hayne Road, Wilmington, North Carolina (United States); Avila N, A.; Calleros M, G., E-mail: Gabriel.Cuevas-Vivas@gnf.com [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verda, Carretera Veracruz-Nautla Km 42.5, Alto Lucero, Veracruz (Mexico)

    2013-10-15

    This paper is informative of the General Electric Hitachi and Global Nuclear Fuel - Americas are collaboration with Comision Federal de Electricidad in a longevity test of thermocouples as power monitoring devices. The test conclusions will serve for final engineering design in detailing the Automated Fixed In-core Probes for calibration of the Local Power Range Monitors (LPRMs) of the Economic Simplified Boiling Water Reactor. This paper introduces the collaboration description and some recent performance evaluation of the thermocouples that are sensitive to gamma radiation and are known generically as Gamma Thermometers (G T). The G Ts in Laguna Verde 2 are radially located inside six instrumentation tubes in the core and consist of seven thermocouples, four are aligned with the LPRM heights and three are axially located between LPRM heights. The Laguna Verde 2 G T test has become the longest test of thermocouples as power monitoring devices in a BWR industry history and confirms their reliability in terms of time-dependent small noise under steady state reactor conditions and good agreement against Traversing In-core Probes power measurements. (Author)

  18. Tratamiento de aguas residuales urbanas mediante lagunas de alta carga: evaluación experimental

    OpenAIRE

    García, Joan; Hernández-Mariné, Mariona; Mujeriego Sahuquillo, Rafael

    1998-01-01

    El objetivo del presente estudio es determinar las condiciones de explotación de dos lagunas experimentales que permiten obtener un mayor rendimento de eliminación de la materia orgánica y los nutrientes del agua residual urbana. También se pretende establecer el rendimiento de los decantadores secundarios experimentales utilizados para la separación de la biomasa del fitoplancton que crece en las lagunas. Se han estudiado durante un año dos lagunas de alta carga provistas cada una de un deca...

  19. The Trail Inventory of Laguna Atascosa National Wildlife Refuge [Cycle 1

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to create a baseline inventory of all non-motorized trails on Laguna Atascosa National Wildlife Refuge. Trails in this inventory are...

  20. 76 FR 24512 - Laguna Cartagena National Wildlife Refuge, Lajas, Puerto Rico; Draft Comprehensive Conservation...

    Science.gov (United States)

    2011-05-02

    ... Fish and Wildlife Service Laguna Cartagena National Wildlife Refuge, Lajas, Puerto Rico; Draft Comprehensive Conservation Plan and Environmental Assessment AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of availability; request for comments. SUMMARY: We, the Fish and Wildlife Service...

  1. Wilderness studies : Public hearing officer request [Laguna Atascosa National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a request for an a certain individual to be the hearing officer for the Laguna Atascosa National Wildlife Refuge public hearing.

  2. Contaminants survey of fish on Laguna Atascosa National Wildlife Refuge, Texas

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The primary source of water for the Laguna Atascosa National Wildlife Refuge (NWR), Texas is the Cayo Atascosa which receives water from the Rio Grande as irrigation...

  3. History and current safety measures at Laguna Palcacocha, Huaraz, Peru

    Science.gov (United States)

    Salazar Checa, César; Cochachin, Alejo; Frey, Holger; Huggel, Christian; Portocarrero, César

    2017-04-01

    Laguna Palcacocha is a large glacier lake in the Cordillera Blanca, Peru, located in the Quillcay catchment, above the city of Huaraz, the local capital. On 13 December 1941, the moraine dam lake collapsed, probably after having been impacted by a large ice avalanche, and triggered a major outburst flood. This GLOF destroyed about a third of the city of Huaraz, causing about 2,000 casualties and is therefore one of the deadliest glacier lake outbursts known in history. In 1974, the Glaciology Unit of Peru, responsible for the studying, monitoring and mitigation works related to glacier hazards installed a reinforcement of the natural moraine dam of the newly filled Laguna Palcacocha, with an artificial drainage channel at 7 m below the crest of the reinforced dam. At that time, the lake had an area of 66,800 m2 and a volume of 0.5 x 106 m3. During the past decades, in the course of continued glacier retreat, Laguna Palcacocha has undergone an extreme growth. In February 2016, the lake had an area of 514,000 m2 (7.7 times the area of 1974) and a volume of more than 17 x 106 m3 (more than 34 times the volume of 1974). At the same time, the city of Huaraz, located 20 km downstream of the lake, grew significantly after its almost complete destruction by the 1970 earthquake. Today, about 120,000 people are living in the city. Due to the persisting possibility for large ice avalanches directly above the Palcacocha lake, this constitutes a high-risk situation, requiring new hazard and risk mitigation measures. As an immediate temporal measure, in order to bridge the time until the realization of a more permanent measure, a syphoning system has been installed in 2011, using about ten 700-m pipes with a 10-inch (25.4 cm) diameter. The aim of this syphoning attempt is to lower the lake level by about 7 m, and therefore reduce the lake volume on the one hand, and also reach a higher dam freeboard. However, the system is less effective than assumed, currently the lake level

  4. Andrés Laguna: a great medical humanist (1499-1559).

    Science.gov (United States)

    Kousoulis, Antonis A; Karamanou, Marianna; Androutsos, George

    2011-01-01

    Andrés Laguna, a Spanish humanist physician of the 16th century, occupies an important position in the history of medicine. An illustrious and brilliant mind, pioneer of anatomy and urology, Laguna proved to be a true pacifist and humanitarian with his knowledge standards and his political eloquence. He deserves to be remembered today as the perfect example of the Renaissance men, a true Homo Universalis.

  5. Hatching success of Caspian terns nesting in the lower Laguna Madre, Texas, USA

    Science.gov (United States)

    Mitchell, C.A.; Custer, T.W.

    1986-01-01

    The average clutch size of Caspian Terns nesting in a colony in the Lower Laguna Madre near Laguna Vista, Texas, USA in 1984 was 1.9 eggs per nest. Using the Mayfield method for calculating success, one egg hatched in 84.1% of the nests and 69.8% of the eggs laid hatched. These hatching estimates are as high or higher than estimates from colonies in other areas.

  6. Radiological protection in Laguna Verde, the challenge of being better; Proteccion radiologica en Laguna Verde, el reto de ser mejores

    Energy Technology Data Exchange (ETDEWEB)

    Serrano R, H. [CFE, Central Laguna Verde, Proteccion Radiologica, Km 42.5 Carretera Cardel-Nautla, Veracruz (Mexico)]. e-mail: hsr98581@cfe.gob.mx

    2008-07-01

    The operation of the nuclear power plants in the last decade is based on the application of standard directed towards the excellence. The nuclear power plant of Laguna Verde (CNLV), is not the exception and in the 18 years of commercial operation, the safety culture has matured in the personnel. Standard and political implemented like in the control of dosimeter alarms, equipment condition, meetings pre-work, the practice of protection to the systems and the fuel, as well as the order and the cleaning have distinguished to the CNLV with other power stations. The sense of property of the personnel towards its work is fundamental for the achievement of results. It is reason for the present work to show since it has been gotten to obtain results directed to the excellence in the activities or of normal operation and recharge, where the security is the principle priority. (Author)

  7. Design optimization of the Laguna Verde nuclear power station fuel recharge; Optimacion del diseno de recargas de combustible para la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Cortes Campos, Carlos Cristobal [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Montes Tadeo, Jose Luis [Instituto Nacional de Investigaciones Nucleares (ININ), Salazar (Mexico)

    1991-12-31

    It is described, in general terms, the procedure that is followed to accomplish the optimization of the recharge design, and an example is shown where this procedure was applied for the analysis of the type BWR reactor of Unit No. 1 of the Laguna Verde Nuclear Power Station. [Espanol] Se describe en terminos generales el procedimiento que se sigue para realizar la optimacion del diseno de recargas, y se muestra un ejemplo en el que se utilizo dicho procedimiento para el analisis del reactor tipo BWR de la unidad 1, de la Central Laguna Verde (CLV).

  8. SEBARAN HORIZONTAL JUVENIL UDANG DI PERAIRAN LAGUNA SEGARA ANAKAN

    Directory of Open Access Journals (Sweden)

    Didik Wahyu Hendro Tjahjo

    2016-03-01

    Full Text Available Terdapat sembilan spesies udang ekonomis penting di  perairan Cilacap dan sekitarnya yang termasuk komoditas perikanan tangkap, dimana sebanyak 34% dari total udang yang tertangkap nelayan, menetas dan dibesarkan di kawasan laguna Segara Anakan. Kondisi ini mengisyaratkan agar dalam pengelolaan perikanan, Segara Anakan perlu mendapat perhatian termasuk aspek ekologis perairan. Untuk itu dilakukan penelitian dengan tujuan untuk mengkaji kelimpahan dan sebaran horizontal juvenil udang  serta preferensi habitatnya di perairan Laguna Segara Anakan. Penelitian lapang dilakukan sebanyak 3 kali frekuensi pengambilan sampel, yaitu pada April, September dan Desember 2012. Pengambilan sampel udang dilakukan dengan alat tangkap mini beam trawl secara terstratifikasi pada delapan titik stasiun pengamatan. Analisa data meliputi kelimpahan dan distribusi horizontal udang, serta preferensi habitatnya. Kelimpahan juvenil udang tertinggi ditemukan di stasiun Klaces dan terendah di stasiun Sapuregel Kecil, dimana nilainya berkisar antara 8-446 ekor/1000 m2 (udang penaeid 8-336 ekor/1000 m2. Post larva udang penaeid tampak dapat  menyesuaikan diri terhadap fluktuasi salinitas yang berkisar antara 2-35 ‰ hingga menjadi juvenil muda serta siap bermigrasi kembali ke laut hingga dewasa untuk melakukan siklus berikutnya. Dari data variasi kelimpahan dan pola sebaran juvenil udang diperoleh gambaran bahwa preferensi habitat bagi udang adalah tipe dasar perairan yang lembut (soft, biasanya terdiri dari campuran lumpur dan pasir.  Kelompok udang penaeid ini tersebar relatif merata di perairan laguna.   There are nine species of economically important shrimp in Cilacap water  which  belonging to  fisheries commodities, where as many as 34 % of the total shrimp caughted are hatched and raised in the Segara Anakan lagoon. This condition implies that in fisheries management option, Segara Anakan lagoon  include its ecological aspects need attention.  In this

  9. Crab death assemblages from Laguna Madre and vicinity, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Plotnick, R.E.; McCarroll, S. (Univ. of Illinois, Chicago (USA)); Powell, E. (Texas A M Univ., College Station (USA))

    1990-02-01

    Crabs are a major component of modern marine ecosystems, but are only rarely described in fossil assemblages. Studies of brachyuran taphonomy have examined either the fossil end-products of the taphonomic process or the very earliest stages of decay and decomposition. The next logical step is the analysis of modern crab death assemblages; i.e., studies that examine taphonomic loss in areas where the composition of the living assemblage is known. The authors studied crab death assemblages in shallow water sediments at several localities in an near Laguna Madre, Texas. Nearly every sample examined contained some crab remains, most commonly in the form of isolated claws (dactyl and propodus). A crab fauna associated with a buried grass bed contained abundant remains of the xanthid crab Dyspanopeus texanus, including carapaces, chelipeds, and thoraxes, as well as fragments of the portunid Callinectes sapidus and the majiid Libinia dubia. Crab remains may be an overlooked portion of many preserved benthic assemblages, both in recent and modern sediments.

  10. Factors controlling navigation-channel Shoaling in Laguna Madre, Texas

    Science.gov (United States)

    Morton, R.A.; Nava, R.C.; Arhelger, M.

    2001-01-01

    Shoaling in the Gulf Intracoastal Waterway of Laguna Madre, Tex., is caused primarily by recycling of dredged sediments. Sediment recycling, which is controlled by water depth and location with respect to the predominant wind-driven currents, is minimal where dredged material is placed on tidal flats that are either flooded infrequently or where the water is extremely shallow. In contrast, nearly all of the dredged material placed in open water >1.5 m deep is reworked and either transported back into the channel or dispersed into the surrounding lagoon. A sediment flux analysis incorporating geotechnical properties demonstrated that erosion and not postemplacement compaction caused most sediment losses from the placement areas. Comparing sediment properties in the placement areas and natural lagoon indicated that the remaining dredged material is mostly a residual of initial channel construction. Experimental containment designs (shallow subaqueous mound, submerged levee, and emergent levee) constructed in high-maintenance areas to reduce reworking did not retain large volumes of dredged material. The emergent levee provided the greatest retention potential approximately 2 years after construction.

  11. Severe Accident Simulation of the Laguna Verde Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    Gilberto Espinosa-Paredes

    2012-01-01

    Full Text Available The loss-of-coolant accident (LOCA simulation in the boiling water reactor (BWR of Laguna Verde Nuclear Power Plant (LVNPP at 105% of rated power is analyzed in this work. The LVNPP model was developed using RELAP/SCDAPSIM code. The lack of cooling water after the LOCA gets to the LVNPP to melting of the core that exceeds the design basis of the nuclear power plant (NPP sufficiently to cause failure of structures, materials, and systems that are needed to ensure proper cooling of the reactor core by normal means. Faced with a severe accident, the first response is to maintain the reactor core cooling by any means available, but in order to carry out such an attempt is necessary to understand fully the progression of core damage, since such action has effects that may be decisive in accident progression. The simulation considers a LOCA in the recirculation loop of the reactor with and without cooling water injection. During the progression of core damage, we analyze the cooling water injection at different times and the results show that there are significant differences in the level of core damage and hydrogen production, among other variables analyzed such as maximum surface temperature, fission products released, and debris bed height.

  12. The Marine Ecology of the Laguna San Rafael (Southern Chile): Ice Scour and Opportunism

    Science.gov (United States)

    Davenport, John

    1995-07-01

    Surveys of the intertidal fauna and flora, the plankton, fish, birds and marine mammals of the Laguna San Rafael were carried out by a Raleigh International Expedition in January-February 1993. The Laguna is dominated by the effects of scouring, low temperature and low salinity produced by the calving, tide-water San Rafael glacier that discharges into the Laguna. The fauna and flora are simple and largely limited to a small sector of the Laguna, relatively unaffected by ice. There is a predominance of herbivorous fish, ducks, geese and swans, feeding mainly on macroalgae. Penguins, cormorants, sea lions and porpoises make up the top predators. The strandline is influenced by very heavy rainfall and supports a fauna of freshwater and terrestrial molluscs and earthworms, fed upon by birds and frogs. Large numbers of mussels are present in the north-eastern sector of the Laguna, but many are found in poor condition, high on the shore. It is suggested that poor condition and mortality are caused by large calving waves that dislodge mussels. Such waves are caused by occasional loss of massive quantities of ice from the glacier.

  13. Petrogenesis of volcanic rocks that host the world-class Agsbnd Pb Navidad District, North Patagonian Massif: Comparison with the Jurassic Chon Aike Volcanic Province of Patagonia, Argentina

    Science.gov (United States)

    Bouhier, Verónica E.; Franchini, Marta B.; Caffe, Pablo J.; Maydagán, Laura; Rapela, Carlos W.; Paolini, Marcelo

    2017-05-01

    We present the first study of the volcanic rocks of the Cañadón Asfalto Formation that host the Navidad world-class Ag + Pb epithermal district located in the North Patagonian Massif, Patagonia, Argentina. These volcanic and sedimentary rocks were deposited in a lacustrine environment during an extensional tectonic regime associated with the breakup of Gondwana and represent the mafic to intermediate counterparts of the mainly silicic Jurassic Chon Aike Volcanic Province. Lava flows surrounded by autobrecciated carapace were extruded in subaerial conditions, whereas hyaloclastite and peperite facies suggest contemporaneous subaqueous volcanism and sedimentation. LA-ICPMS Usbnd Pb ages of zircon crystals from the volcanic units yielded Middle Jurassic ages of 173.9 ± 1.9 Ma and 170.8 ± 3 Ma. In the Navidad district, volcanic rocks of the Cañadón Asfalto Formation show arc-like signatures including high-K basaltic-andesite to high-K dacite compositions, Rb, Ba and Th enrichment relative to the less mobile HFS elements (Nb, Ta), enrichment in light rare earth elements (LREE), Ysbnd Ti depletion, and high Zr contents. These characteristics could be explained by assimilation of crustal rocks in the Jurassic magmas, which is also supported by the presence of zircon xenocrysts with Permian and Middle-Upper Triassic ages (281.3 Ma, 246.5, 218.1, and 201.3 Ma) and quartz xenocrysts recognized in these volcanic units. Furthermore, Sr and Nd isotope compositions suggest a contribution of crustal components in these Middle Jurassic magmas. High-K basaltic andesite has initial 87Sr/86Sr ratios of 0.70416-0.70658 and ξNd(t) values of -5.3 and -4. High-K dacite and andesite have initial 87Sr/86Sr compositions of 0.70584-0.70601 and ξNd(t) values of -4,1 and -3,2. The range of Pb isotope values (206Pb/204Pb = 18.28-18.37, 207Pb/204Pb = 15.61-15.62, and 208Pb/204Pb = 38.26-38.43) of Navidad volcanic rocks and ore minerals suggest mixing Pb sources with contributions of

  14. The Late Pliocene mafic lavas from the Camusú Aike volcanic field (˜50°S, Argentina): Evidence for geochemical variability in slab window magmatism

    Science.gov (United States)

    D'Orazio, M.; Innocenti, F.; Manetti, P.; Haller, M. J.; Di Vincenzo, G.; Tonarini, S.

    2005-01-01

    The Camusú Aike volcanic field (CAVF), part of the discontinuous N-S-trending belt of Cenozoic mafic lava formations that occur in a backarc position along extra-Andean Patagonia, is located in southern Patagonia (˜50°S, Santa Cruz province), approximately 70 km east of the extensive Meseta de las Vizcachas and just south of the upper Río Santa Cruz valley. The CAVF volcanics cover a surface of ˜200 km 2 and occur mainly as lava flows and scoria cones. They are subdivided into two groups: Group I volcanics are high-TiO 2, low-Mg# olivine-hypersthene-normative basalts and trachybasalts that erupted at about 2.9 Ma; Group II lavas are much less abundant, more primitive basaltic andesites that erupted at about 2.5 Ma. Both groups show a within-plate geochemical signature, though it is more marked in Group I lavas. The main geochemical characteristics, age, and location of CAVF volcanics are consistent with the slab window opening model proposed by different authors for the genesis of the Miocene-Recent mafic magmatism of Patagonia south of 46.5°S. The whole-rock geochemical and Sr-Nd isotope features of Group I lavas ( 87Sr/ 86Sr=0.7035-0.7037; 143Nd/ 144Nd=0.51288-0.51291) indicate a genetic link between these lavas and the primitive basalts in southernmost Patagonia (Pali Aike volcanic field and Estancia Glencross area), which have been interpreted as melting products of an isotopically depleted asthenosphere. The relatively evolved compositions of the erupted Group I magmas are modeled by a polybaric crystal fractionation process without significant involvement of crustal contamination. The more primitive Group II lavas are strongly depleted in incompatible elements, have slightly higher (LREE+Ba+Th+U)/HFSE ratios, and have more enriched Sr-Nd isotope compositions ( 87Sr/ 86Sr≈0.7039; 143Nd/ 144Nd≈0.51277) that are more akin to the Patagonian basalts farther to the north. The most likely explanation for the geochemical features of Group II lavas is the

  15. Analysis of the stability of events occurred in Laguna Verde; Analisis de estabilidad de eventos ocurridos en Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Castillo D, R.; Ortiz V, J. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Calleros M, G. [CFE, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km. 42.5, Alto Lucero, Veracruz (Mexico)

    2005-07-01

    The new fuel designs for operation cycles more long have regions of uncertainty bigger that those of the old fuels, and therefore, they can have oscillations of power when an event is presented that causes that the reactor operates to high power and low flow of coolant. During the start up of the reactor there are continued procedures that avoid that oscillations are presented with that which makes sure the stable behavior of the reactor. However, when the reactor is operating to nominal conditions and they are shot or they are transferred to low speed the recirculation pumps, it cannot make sure that the reactor doesn't present oscillations of power when entering to the restricted operation regions. The methods of stability analysis commonly use signs of neutronic noise that require to be stationary, but after a transitory one where they commonly get lost the recirculation pumps the signs they don't have the required characteristics, for what they are used with certain level of uncertainty by the limited validity of the models. In this work the Prony method is used to determine the reactor stability, starting from signs of transitory and it is compared with autoregressive models. Four events are analyzed happened in the Laguna Verde power plant where the reactor was in the area of high power and low flow of coolant, giving satisfactory results. (Author)

  16. Estudio y monitoreo de glaciares y lagunas altoandinas: plan de trabajo institucional 2005

    OpenAIRE

    Ministerio de Agricultura; Instituto Nacional de Recursos Naturales. Intendencia de Recursos Hídricos. Unidad de Glaciología y Recursos Hídricos

    2005-01-01

    Muestra el plan de trabajo institucional correspondiente al año 2005 en el marco del proyecto "Estudio y monitoreo de glaciares y lagunas altoandinas". En virtud de ello, proporciona datos generales del proyecto así como detalles del marco lógico, análisis FODA, estrategias de ejecución, beneficios del proyecto, actividades, tareas y productos, entre otros aspectos. Cabe señalar que el objetivo del proyecto es evaluar y monitorear el comportamiento de los glaciares y lagunas con la finalidad ...

  17. Macroalgas bentónicas de la laguna de Tampamachoco, Veracruz, México

    OpenAIRE

    Kurt M. Dreckmann; Pérez-Hemández, Marco A

    2016-01-01

    A total of 23 macroalgal species were identified in Laguna Tampamachoco, Veracruz, Mexico: 9 ChIorophyceae, 2 Phaeophyceae and 12 Rhodophyceae. Algal richness per area is relatively higher (60-100 times) than in another coastal lagoon and one estuary of the area (Laguna Madre and Tamiahua with 29 and 22 species respectively). We report the presence of Phaeophyceae in this environment for the first time. The three sites have 58 species in total, twice the number reported from any other North A...

  18. Investigation of chikungunya fever outbreak in Laguna, Philippines, 2012

    Directory of Open Access Journals (Sweden)

    Julius Erving Ballera

    2015-12-01

    Full Text Available Background: In July 2012, the Philippines National Epidemiology Center received a report of a suspected chikungunya fever outbreak in San Pablo City, Laguna Province, the first chikungunya cases reported from the city since surveillance started in 2007. We conducted an outbreak investigation to identify risk factors associated with chikungunya. Methods: A case was defined as any resident of Concepcion Village in San Pablo City who had fever of at least two days duration and either joint pains or rash between 23 June and 6 August 2012. Cases were ascertained by conducting house-to-house canvassing and medical records review. An unmatched case-control study was conducted and analysed using a multivariate logistic regression. An environmental investigation was conducted by observing water and sanitation practices, and 100 households were surveyed to determine House and Breteau Indices. Human serum samples were collected for confirmation for chikungunya IgM through enzyme-linked immunosorbent assay. Results: There were 98 cases identified. Multivariate analysis revealed that having a chikungunya case in the household (adjusted odds ratio [aOR]: 6.2; 95% confidence interval [CI]: 3.0–12.9 and disposing of garbage haphazardly (aOR: 2.7; 95% CI: 1.4–5.4 were associated with illness. House and Breteau Indices were 27% and 28%, respectively. Fifty-eight of 84 (69% serum samples were positive for chikungunya IgM. Conclusion: It was not surprising that having a chikungunya case in a household was associated with illness in this outbreak. However, haphazard garbage disposal is not an established risk factor for the disease, although this could be linked to increased breeding sites for mosquitoes.

  19. Investigation of chikungunya fever outbreak in Laguna, Philippines, 2012

    Science.gov (United States)

    Zapanta, Ma Justina; de los Reyes, Vikki Carr; Sucaldito, Ma Nemia; Tayag, Enrique

    2015-01-01

    Background In July 2012, the Philippines National Epidemiology Center received a report of a suspected chikungunya fever outbreak in San Pablo City, Laguna Province, the first chikungunya cases reported from the city since surveillance started in 2007. We conducted an outbreak investigation to identify risk factors associated with chikungunya. Methods A case was defined as any resident of Concepcion Village in San Pablo City who had fever of at least two days duration and either joint pains or rash between 23 June and 6 August 2012. Cases were ascertained by conducting house-to-house canvassing and medical records review. An unmatched case-control study was conducted and analysed using a multivariate logistic regression. An environmental investigation was conducted by observing water and sanitation practices, and 100 households were surveyed to determine House and Breteau Indices. Human serum samples were collected for confirmation for chikungunya IgM through enzyme-linked immunosorbent assay. Results There were 98 cases identified. Multivariate analysis revealed that having a chikungunya case in the household (adjusted odds ratio [aOR]: 6.2; 95% confidence interval [CI]: 3.0–12.9) and disposing of garbage haphazardly (aOR: 2.7; 95% CI: 1.4–5.4) were associated with illness. House and Breteau Indices were 27% and 28%, respectively. Fifty-eight of 84 (69%) serum samples were positive for chikungunya IgM. Conclusion It was not surprising that having a chikungunya case in a household was associated with illness in this outbreak. However, haphazard garbage disposal is not an established risk factor for the disease, although this could be linked to increased breeding sites for mosquitoes. PMID:26668759

  20. Investigation of chikungunya fever outbreak in Laguna, Philippines, 2012.

    Science.gov (United States)

    Ballera, Julius Erving; Zapanta, Ma Justina; de los Reyes, Vikki Carr; Sucaldito, Ma Nemia; Tayag, Enrique

    2015-01-01

    In July 2012, the Philippines National Epidemiology Center received a report of a suspected chikungunya fever outbreak in San Pablo City, Laguna Province, the first chikungunya cases reported from the city since surveillance started in 2007. We conducted an outbreak investigation to identify risk factors associated with chikungunya. A case was defined as any resident of Concepcion Village in San Pablo City who had fever of at least two days duration and either joint pains or rash between 23 June and 6 August 2012. Cases were ascertained by conducting house-to-house canvassing and medical records review. An unmatched case-control study was conducted and analysed using a multivariate logistic regression. An environmental investigation was conducted by observing water and sanitation practices, and 100 households were surveyed to determine House and Breteau Indices. Human serum samples were collected for confirmation for chikungunya IgM through enzyme-linked immunosorbent assay. There were 98 cases identified. Multivariate analysis revealed that having a chikungunya case in the household (adjusted odds ratio [aOR]: 6.2; 95% confidence interval [CI]: 3.0-12.9) and disposing of garbage haphazardly (aOR: 2.7; 95% CI: 1.4-5.4) were associated with illness. House and Breteau Indices were 27% and 28%, respectively. Fifty-eight of 84 (69%) serum samples were positive for chikungunya IgM. It was not surprising that having a chikungunya case in a household was associated with illness in this outbreak. However, haphazard garbage disposal is not an established risk factor for the disease, although this could be linked to increased breeding sites for mosquitoes.

  1. Determination of Piperine in Uyghur medinice Aike Majun by HPLC%HPLC法测定维吾尔药柯艾蜜膏中胡椒碱的含量

    Institute of Scientific and Technical Information of China (English)

    吐鲁洪·卡地尔; 努尔拉江·帕合尔丁; 希尔艾力·吐尔逊

    2016-01-01

    目的:建立艾柯蜜膏中胡椒碱的含量测定方法.方法:采用HPLC法测定艾柯蜜膏中胡椒碱的含量,用十八烷基硅烷键合硅胶为填充剂,以甲醇-水(70∶30)为流动相;检测波长为343nm,流速为1.0 mL· min-1.结果:线性范围116.16ng~271.04ng,平均回收率为100.9%,RSD%=3.5%(n=6).结论:该法简便,灵敏度高,重现性好,可作为该制剂的质量控制方法.%Objective:To develop a HPLC method for determination of piperine in Uyghur medinice Aike majun.Methods:HPLC was applied for determination of piperine in Uyghur medinice Aike majun.The column of Phenomenex luna C18 (4.6 mm×250 mm,4 μm) was used in HPLC.The methanol-water (70∶30) was taken as mobile phase;detection wave-length was set at 343 nm.The flow rate was 1.0 mL·min-1.Results:The linear range of piperine was l16.16ng~271.04ng,and the recovery was 100.9% (RSD=-3.5%).Conclusion:This method is simple,with high sensitivity and good reproducibility;it can be used for the quality control of Aike majun.

  2. Dormideros de Grulla Común en la Laguna de Gallocanta

    OpenAIRE

    2006-01-01

    Citación completa: Bautista LM. 2006. Dormideros de Grulla Común en la Laguna de Gallocanta. págs.: 133-136, en: Fauna en acción; Guía para observar comportamiento animal en España. Eds.: M. Soler y colaboradores. Lynx edicions. Bellaterra, Barcelona.

  3. A pollen diagram from “Laguna de la Herrera” (Sabana de Bogota)

    NARCIS (Netherlands)

    Hammen, van der T.; Gonzalez, E.

    1965-01-01

    The Laguna de La Herrera (alt. ca 2550 m) is a lake situated on the western border of the Sabana de Bogotá, near Mosquera (dept. of Cundinamarca, Colombia) (fig. 2). This part of the Sabana has a relatively dry climate (appr. 600—700 mm rainfall), as it lies in the rain-shadow of the hills that bord

  4. Redhead duck behavior on lower Laguna Madre and adjacent ponds of southern Texas

    Science.gov (United States)

    Mitchell, C.A.; Custer, T.W.; Zwank, P.J.

    1992-01-01

    Behavior of redheads (Aythya americana) during winter was studied on the hypersaline lower Laguna Madre and adjacent freshwater to brackish water ponds of southern Texas. On Laguna Madre, feeding (46%) and sleeping (37%) were the most common behaviors. Redheads fed more during early morning (64%) than during the rest of the day (40%); feeding activity was negatively correlated with temperature. Redheads fed more often by dipping (58%) than by tipping (25%), diving (16%), or gleaning (0.1%). Water depth was least where they fed by dipping (16 cm), greatest where diving (75 cm), and intermediate where tipping (26 cm). Feeding sequences averaged 5.3 s for dipping, 8.1 s for tipping, and 19.2 s for diving. Redheads usually were present on freshwater to brackish water ponds adjacent to Laguna Madre only during daylight hours, and use of those areas declined as winter progressed. Sleeping (75%) was the most frequent behavior at ponds, followed by preening (10%), swimming (10%), and feeding (0.4%). Because redheads fed almost exclusively on shoalgrass while dipping and tipping in shallow water and shoalgrass meadows have declined in the lower Laguna Madre, proper management of the remaining shoalgrass habitat is necessary to ensure that this area remains the major wintering area for redheads.

  5. Design Study for a Future Laguna-LBNO Long-Baseline Neutrino Facility at CERN

    CERN Document Server

    Alabau-Gonzalvo, J; Antoniou, F; Benedikt, M; Calviani, M; Efthymiopoulos, I; Ferrari, A; Garoby, R; Gerigk, F; Gilardoni, S; Goddard, B; Kosmicki, A; Lazaridis, C; Osborne, J; Papaphillippou, Y; Parfenova, A; Shaposhnikova, E; Steerenberg, R; Velten, P; Vincke, H

    2013-01-01

    The Large Apparatus studying Grand Unification and Neutrino Astrophysics (LAGUNA) study [1] investigated seven pre-selected underground sites in Europe (Finland, France, Italy, Poland, Romania, Spain and UK), capable of housing large volume detectors for terrestrial, accelerator generated and astrophysical neutrino research. The study was focused on geo-technical assessment of the sites, concluding that no show-stoppers exist for the construction of the required large underground caverns in the chosen sites. The LAGUNA-LBNO FP7/EC-funded design study extends the LAGUNA study in two key aspects: the detailed engineering of detector construction and operation, and the study of a long-baseline neutrino beam from CERN, and possibly other accelerator centres in Europe. Based on the findings of the LAGUNA study, the Pyh¨asalmi mine in Finland is chosen as prime site for the far detector location. The mine offers the deepest underground location in Europe (-1400 m) and a baseline of 2’300 km from CERN (Fig. 1). ...

  6. Subsidence History of the Laguna Salada Basin in Northeastern Baja California, Mexico

    Science.gov (United States)

    Contreras, J.; Martin-Barajas, A.; Herguera, J.

    2008-12-01

    The Salton Trough region in southern California and the Mexicali valley in northwestern Mexico are areas of (i) rapid subsidence due to trans-tension along the San Andreas-Imperial fault system, and (ii) high flux of sediments transported by the Colorado River, all of which confer this region with a high potential to preserve a complete record of climatic and tectonic activity information. Here we present the subsidence history of the Laguna Salada basin, and the history of activity of the master bounding faults on its eastern side. The Laguna Salada is a lacustrine basin located west of the Mexicali valley and to the south of the Salton Trough. Sedimentological as well as time series analyses performed on two 42 m-long cores drilled in the center of the basin, estimated to span the past 50 and 70KaBP, indicate a modulation of the late Quaternary stratigraphy by cyclic variations in lake level driven by Milankovitch forcing. Based on these results we derive the long-term history of the basin from a gamma-ray log recovered from a 2.8 km-deep geothermal borehole drilled by the Mexican Power Company adjacent to the Laguna Salada fault. The stratigraphy of the deep borehole reveals a history of activity pulses related to the initial breakage of the Laguna Salada fault and its interaction with neighboring faults. A first pulse started at 1.5 Ma and records the initiation of the Laguna Salada fault and rapid uplift of the crystalline block of the Sierra Cucapa. A second pulse started around 1 Ma, and is very likely related to the hard linking of the Laguna Salada fault with the Cañada David detachment by the Cañon Rojo fault. The onset of the Laguna Salada fault at 1.5 Ma appears to be synchronous with an early Pleistocene regional fault reorganization among the San Jacinto, San Andreas and Elsinore fault systems in southern California, suggesting that this reorganization may have affected a large area from San Gorgonio pass to the northern Gulf of California.

  7. Potencial uso agrícola del agua de la laguna Unamuno. Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    V. Bohn

    2007-01-01

    Full Text Available La laguna Unamuno se localiza en el sudoeste de la provincia de Buenos Aires (Argentina y pertenece a la cuenca del arroyo Napostá Chico. Su origen se relaciona con la topografía y con el incremento de las precipitaciones promedio de la región durante las últimas décadas. Debido a que no existen experiencias de riego con agua de la laguna, el objetivo de este trabajo es determinar su aptitud para riego y el riesgo de sodificación del suelo de la cubeta de inundación. El grado de dicho riesgo es un aporte al conocimiento del estado actual de los suelos de la cubeta de inundación y es un parámetro a tener en cuenta en futuros planes de manejo para el uso de la laguna en suelos aledaños. Los parámetros físicos y químicos del agua se obtuvieron a partir del análisis de muestras correspondientes al período abril/04-junio/05. Se aplicó el índice de absorción de sodio y el de carbonato sódico residual. Se determinó que existe un alto riesgo de sodificación de los suelos que están en contacto con el agua de la laguna. Sin embargo, la permanencia de los mismos y la variación areal de la laguna contrarrestaron los efectos de la permanencia de agua con alto contenido de sodio(Na, cloro y sulfatos sobre tierras productivas.

  8. DINAMIKA LARVA IKAN SEBAGAI DASAR OPSI PENGELOLAAN SUMBER DAYA IKAN DI LAGUNA PULAU PARI KEPULAUAN SERIBU

    Directory of Open Access Journals (Sweden)

    Reny Puspasari

    2013-05-01

    Full Text Available Proses rekruitmen populasi ikan sangat ditentukan oleh kelangsungan hidup larva ikan yang ada di daerah pemijahan/asuhan. Laguna Pulau Pari merupakan daerah pemjahan bagi banyak jenis larva ikan karang. Tujuan dari penelitian ini adalah untuk mengkaji dinamika kelimpahan dan komposisi dari larva ikan di laguna Pulau Pari. Hasil penelitian menunjukkan bahwa kelimpahan larva ikan yang ditemukan berkisar antara 1,0 x103 – 14,7 x 103 individu/m3. Puncak kelimpahan tertinggi terjadi pada bulan Juli dan Oktober. Larva ikan ditemukan tersebar di semua lokasi pengamatan. Larva pada fase perkembangan pre flexion ditemukan dalam presentase yang paling tinggi. Selama masa pengamatan ditemukan 79 famili larva ikan yang didominasi oleh Pomacentridae, Aulostomidae, Blenniidae, Engraulidae dan Pinguipedidae. Dinamika yang terjadi pada larva ikan dapat dijadikan dasar bagi pengelolaan perikanan di wilayah Laguna Pulau Pari dengan cara memperluas daerah perlindungan laut dan rehabilitasi ekosistem Laguna Pulau Pari, sehingga peran dan fungsinya sebagai pemasok rekrut bagi stok ikan di perairan sekitarnya terjaga.   Fish Recruitment is, in turn, thought to be directly related to the survival of the early life stages in the spawning/nursery ground. Pulau Pari Laguna is considered as a spawning ground for many reef fishes. The aims of the research were to investigate the dynamic of abundance and composition of fish larvae in Pulau Pari lagune. The Results show, fish larvae abundance range between 1,0 x 103 – 14,7 x 103 ind/m3. Highest larval abundance occurred on July and October, which predicted as the month of fish larvae production seasons. Fish larvae were distributed in all part of the lagune. Larvae in the pre flexion stage found in the highest precentation compare to other. Totally 79 families of reef fish larvae were found during June – November 2010 dominated by Pomacentridae, Aulostomidae, Blenniidae, Engraulidae and Pinguipedidae.

  9. Migration chronology and distribution of redheads on the lower Laguna Madre, Texas

    Science.gov (United States)

    Custer, Christine M.; Custer, T.W.; Zwank, P.J.

    1997-01-01

    An estimated 80% of redheads (Aythya americana) winter on the Laguna Madre of southern Texas and Mexico. Because there have been profound changes in the Laguna Madre over the past three decades and the area is facing increasing industrial and recreational development, we studied the winter distribution and habitat requirements of redheads during two winters (1987-1988 and 1988-1989) on the Lower Laguna Madre, Texas to provide information that could be used to understand, identify, and protect wintering redhead habitat. Redheads began arriving on the Lower Laguna Madre during early October in 1987 and 1988, and continued to arrive through November. Redhead migration was closely associated with passing weather fronts. Redheads arrived on the day a front arrived and during the following two days; no migrants were observed arriving the day before a weather front arrived. Flock size of arriving redheads was 26.4 ± 0.6 birds and did not differ among days or by time of day (morning midday, or afternoon). Number of flocks arriving per 0.5 h interval (arrival rate) was greater during afternoon (21.7 ± 0.6) than during morning (4.3 ± 1.2) or midday (1.5 ± 0.4) on the day of frontal passage and during the first day after frontal passage. Upon arrival, redhead flocks congregated in the central portion of the Lower Laguna Madre. They continued to use the central portion throughout the winter, but gradually spread to the northern and southern ends of the lagoon. Seventy-one percent of the area used by flocks was vegetated with shoalgrass (Halodule wrightii) although shoalgrass covered only 32% of the lagoon. Flock movements seemed to be related to tide level; redheads moved to remain in water 12-30 cm deep. These data can be used by the environmental community to identify and protect this unique and indispensable habitat for wintering redheads.

  10. El registro de la pequena edad de hielo en lagunas pampeanas

    Directory of Open Access Journals (Sweden)

    Cecilia Laprida

    2009-12-01

    Full Text Available Se conoce como Pequeña Edad de Hielo (LIA al episodio acontecido entre el siglo 16 y mediados del siglo 19, durante el cual el clima en Europa se tornó frío y ocasionalmente tormentoso. En ciertas partes de Europa, las observaciones instrumentales lo abarcan parcialmente, pero para Sudamérica no se dispone de registros instrumentales contemporáneos a dicho evento. Con el objetivo de obtener nuevas evidencias para el período comprendido por la Pequeña Edad de Hielo en la llanura pampeana, se analizaron testigos cortos de la laguna de Chascomús y de la laguna del Monte los que, de acuerdo a dataciones AMS, abarcan los últimos 500 años. Ambos testigos constan de tres secuencias granodecrecientes. El análisis del registro de la laguna de Chascomús ha permitido reconocer un período benigno desde fines del siglo 15 hasta alrededor del 1700, cuando se evidencia una retracción de la laguna que inaugura un período seco. Este episodio habría continuado por casi 150 años y se revierte alrededor de 1850, momento a partir del cual los eventos de excesos hídricos comenzaron a dominar el escenario pampeano. La base del testigo de la laguna de Monte fue datada en 1441-1494 AD. Si bien el modelo de edades para este testigo aún no ha podido ser bien establecido, los eventos de Chascomús y Monte podrían ser correlacionables y expresar tendencias seculares regionales de la humedad.

  11. Influence of the substrate on maar-diatreme volcanoes — An example of a mixed setting from the Pali Aike volcanic field, Argentina

    Science.gov (United States)

    Ross, Pierre-Simon; Delpit, Séverine; Haller, Miguel J.; Németh, Károly; Corbella, Hugo

    2011-04-01

    The morphologic parameters, pyroclastic deposits and evolution of maar-diatreme volcanoes are affected by the type of environment in which they are emplaced. End-member cases are a hard substrate (rocks) and a soft substrate (unconsolidated volcaniclastic or sedimentary deposits). In this paper, we present an example of a volcanic complex emplaced in a mixed hard-soft setting from the Pali Aike volcanic field (PAVF) near the Argentina-Chile border. The Plio-Pleistocene PAVF is an alkaline, mafic, back-arc monogenetic field which contains over 100 phreatomagmatic volcanoes. The studied volcanic complex contains two large coalescent maars overlain by scoria and spatter. The 1.4 × 1.3 km East Maar has better exposures than the shallower, 1.9 km-wide West Maar and seems to have been less modified by post-eruptive processes. The tephra rim of the East Maar was studied in detail and we infer it was produced mostly by base surges from phreatomagmatic eruption columns, with rare instances of intercalated scoria fall layers. Based on regional information, the general pre-maar stratigraphy is dominated by sedimentary and volcaniclastic rocks of the Magallanes Basin, including a thick poorly consolidated upper unit dating from the Miocene. These are overlain by Plio-Pleistocene fluvio-glacial deposits and PAVF lavas, some of which are exposed in the East Maar just below the phreatomagmatic deposits. All of these units are represented as lithic clasts in the tephra rim of the East Maar, the most abundant being the clasts from the earlier basaltic lavas and rock fragments derived from the glacial deposits. There is no specific evidence for a deep diatreme under the East Maar, and in this particular case, the mixed environment seems to have produced a maar-diatreme volcano typical of a soft substrate.

  12. Evaluacion constante del virus de la enfermedad de Newcastle en aves silvestres de la laguna albufera de medio mundo

    National Research Council Canada - National Science Library

    Mendoza R., Luis; Icochea D., Eliana; Gonzalez Z., Armando; Gonzalez V., Rosa

    2012-01-01

    El estudio evaluo la presencia del virus de la Enfermedad de Newcastle en la laguna Albufera de Medio Mundo, situada al norte de Lima, y habitada por diversas especies de aves silvestres y migratorias...

  13. STATUS TERKINI DAN ALTERNATIF PENGELOLAAN SUMBER DAYA IKAN DI LAGUNA SEGARAANAKAN, CILACAP

    Directory of Open Access Journals (Sweden)

    Didik Wahyu Hendro Tjahjo

    2013-05-01

    Full Text Available Laguna Segara Anakan mempunyai peran penting sebagai kawasan pengelolaan perikanan udang sebagai daerah asuhan. Penyempitan dan pendangkalan perairan laguna sangat mempengaruhi populasi larva dan juvenil udang. Tujuan penulisan ini adalah untuk mengkaji hubungan perubahan lingkungan terhadap sumberdaya udang. Kandungan oksigen terlarut relatif rendah, kondisi tersebut dalam jangka panjang akan berpengaruh terhadap laju pertumbuhan ikan dan udang, dan akhirnya berdampak langsung terhadap laju rekruitmen udang dan ikan untuk perairan Segara Anakan dan perairan laut sekitar Cilacap. Kelimpahan larva udang dan ikan di perairan laguna ini berkisar antara 87 – 63,451 ind./1000 m3, dan kelimpahan juvenil tersebut berkisar antara 0 – 25,263 ind./1000 m2, dimana selama pengamatan didominasi oleh juvenil udang. Total produksi (ikan dan udang di Segara Anakan dari tahun ke tahun mengalami penurunan yang signifikan dalam periode tahun 1987-2004. Kondisi tersebut disebabkan luas perairan laguna semakin sempit dan dangkal, serta intensitas penangkapan semakin tinggi. Oleh karena itu, perlu suatu pengelolaan yang menyeluruh terhadap sumber daya laguna agar mampu mengurangi laju penurunan produksinya, yaitu pengelolaan sumberdaya perikanan di laguna Segara Anakan sebagai satu kesatuan ekologi yang utuh. Segara Anakan lagoon have an important role as the shrimp fishery management area in which shrimp species using this area of lagoons as a nursery ground. Refinement and siltation of the lagoon waters greatly affect populations of larvae and juvenile shrimp. The purpose of this paper is to study the relationship of environmental change on shrimp resources. Dissolved oxygen is relatively low, the condition will affect the growth of fish and shrimp in the long time, and ultimately it have a direct impact on the rate of recruitment of shrimp and fish for Segara Anakan waters and coastal waters around Cilacap. Abundance of larval shrimp and fish in this lagoon

  14. Modernization of electric power systems of the Laguna Verde Nuclear Power Plant; Modernizacion de los sistemas electricos de potencia de la Central Nuclear de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Gabaldon, M. A.; Gonzalez, J. J.; Prieto, I.

    2011-07-01

    The Power Increase Project of Laguna Verde Nuclear Plant has entailed the replacement, in one unique outage, of the main power electrical systems of the Plant (Isolated Phase Bars, Generator Circuit Breaker and Main Transformer) as well as the replacement of the Turbo-group. The simultaneous substitution of these entire system has never been done by any other Plant in the world, representing an engineering challenge that embraced the design of the new equipment up to the planning, coordination and management of the construction and commissioning works, which were successfully carried out by Iberdrola within the established outage period /47 days) for both units. (Author)

  15. Tres patos ocasionales en la Sabana de Bogotá y la Laguna de Fúquene

    Directory of Open Access Journals (Sweden)

    Borrero José Ignacio

    1944-12-01

    Full Text Available Agradezco al Dr. Armando Dugand la ayuda que se sirvió dispensarme para la presentación de este articulo. Creo de interes, para principiar, hacer una breve descripción de las condiciones de la Sabana de Bogotá y la Laguna de Fúquene, como localidades de paso o estacionamiento temporal para las especies migratorias de Anátidas.  La Sabana de Bogotá ocupa una vasta altiplanicie de unos 2000 kilómetros cuadrados a 2600 mts. de altura media, rodeada de montanas o cerros en toda su extensión y cruzada por pequeños rios. El rio Bogotá, que la atraviesa, forma en sus riberas y en casi toda su extensión grandes lagunas y pantanos apropiados para la llegada de los patos y otras aves acuáticas que anualmente vienen del Norte y otras regiones.

  16. Trace elements and organochlorines in the shoalgrass community of the lower Laguna Madre, Texas.

    Science.gov (United States)

    Custer, T W; Mitchell, C A

    1993-05-01

    Our objectives were to measure concentrations of seven trace elements and 14 organochlorine compounds in sediment and biota of the shoalgrass (Halodule wrightii) community of the lower Laguna Madre of south Texas and to determine whether chemicals associated with agriculture (e.g. mercury, arsenic, selenium, organochlorine pesticides) were highest near agricultural drainages. Arsenic, mercury, selenium, lead, cadmium, and organochlorines were generally at background concentrations throughout the lower Laguna Madre. Nickel and chromium concentrations were exceptionally high in shrimp and pinfish (Lagodon rhomboides), which is difficult to explain because of no known anthropogenic sources for these trace elements. For sediment and blue crabs (Callinectes sapidus), mercury was highest near agricultural drainages. Also, DDE was more frequently detected in blue crabs near agricultural drainages than farther away. In contrast, selenium concentrations did not differ among collecting sites and arsenic concentrations were lowest in shoalgrass, blue crabs, and brown shrimp (Penaeus aztecus) near agricultural drainages.

  17. Trace elements and organochlorines in the shoalgrass community of the lower Laguna Madre

    Science.gov (United States)

    Custer, T.W.; Mitchell, C.A.

    1993-01-01

    Our objectives were to measure concentrations of seven trace elements and 14 organochlorine compounds in sediment and biota of the shoalgrass (Halodule wrightii) community of the lower Laguna Madre of south Texas and to determine whether chemicals associated with agriculture (e.g. mercury, arsenic, selenium, organochlorine pesticides) were highest near agricultural drainages. Arsenic, mercury, selenium, lead, cadmium, and organochlorines were generally at background concentrations throughout the lower Laguna Madre. Nickel and chromium concentrations were exceptionally high in shrimp and pinfish (Lagodon rhomboides), which is difficult to explain because of no known anthropogenic sources for these trace elements. For sediment and blue crabs (Callinectes sapidus), mercury was highest near agricultural drainages. Also, DDE was more frequently detected in blue crabs near agricultural drainages than farther away. In contrast, selenium concentrations did not differ among collecting sites and arsenic concentrations were lowest in shoalgrass, blue crabs, and brown shrimp (Penaeus aztecus) near agricultural drainages.

  18. La vida cotidiana de La Laguna en la prensa del siglo XIX

    Directory of Open Access Journals (Sweden)

    Lic. Enrique Rodríguez López

    1998-01-01

    Full Text Available El binomio ciudad y comunicación enmarca ámbitos de trabajo muy variados. El propósito del autor es analizar cómo se refleja la vida cotidiana de la ciudad en la prensa que se edita en el mismo entorno. Las coordenadas de tiempo (siglo XIX y lugar (La Laguna no son casuales, pues nos permiten estudiar el tratamiento que la prensa de la época le da a la vida cotidiana en un ámbito de nacimiento, en el pasado que parece reunir muchos motivos de interés. La Laguna, ciudad con fecha de nacimiento, en el pasado siglo experimentó una serie de cambios importantes y muchos de ellos pasan casi inadvertidos por considerarse como aspectos menores para su estudio. La prensa de la época nos va a ayudar a formarnos una idea aproximada del acontecer cotidiano en la ciudad.

  19. Design Options of a High-power Synchrotron for Laguna-LBNO

    CERN Document Server

    Papaphilippou, Y; Alekou, A; Antoniou, F; Benedikt, M; Efthymiopoulos, I; Garoby, R; Gerigk, F; Goddard, B; Lazaridis, C; Parfenova, A; Shaposhnikova, E; Steerenberg, R

    2013-01-01

    Design studies have been initiated at CERN, exploring the prospects of future high-power proton beams for producing neutrinos, within the LAGUNA-LBNO project. These studies include the design of a 2 MW high-power proton synchrotron (HP-PS) using the LP-SPL as injector. This paper resumes the design options under study in order to reach this high power, and their implications regarding layout, magnet technology, beam loss control and RF considerations

  20. TRATAMIENTO DE EFLUENTES PISCÍCOLAS (TILAPIA ROJA EN LAGUNAS CON Azolla pinnata

    Directory of Open Access Journals (Sweden)

    GUILLERMO CHAUX F

    2013-12-01

    Full Text Available Los sistemas con plantas acuáticas flotantes son una alternativa económicamente sostenible para el tratamiento de efluentes piscícolas. Se evaluó a escala piloto el desempeñ,o de un sistema de lagunas con Azolla pinnata en serie para el tratamiento de efluentes de cría de tilapia roja durante el proceso de levante y engorde. El sistema construido en la piscícola La Yunga (Popayán, Colombia consistió en dos líneas de cinco lagunas en serie; la primera con A. pinnata y la segunda sin la planta acuática; cada laguna se operó con un tiempo de detención de un día. La evaluación se realizó en época seca. La producción de Azolla fresca osciló entre 42 y 87 g/m2.d y el contenido de proteína entre 18,5% y 20,4%. Las eficiencias de remoción obtenidas en las líneas (con Azolla, sin Azolla fueron respectivamente: 56% y 46% DBO5; 49% y 26% DQO; 56% y 33% SST; 28% y 36% N-NTK; -108% y 23% N-NH4+; 64% y 34% fósforo total, mostrando superioridad del sistema con Azolla. Con solo tres lagunas en serie plantadas con A. pinnata se alcanzan las eficiencias máximas obtenidas en la remoción de DBO5, DQO, SST y fósforo total.

  1. Persistent organic pollutants in sediment cores of Laguna El Yucateco, Tabasco, Southeastern Gulf of Mexico

    OpenAIRE

    Guadalupe Ponce-Vélez; Alfonso Vázquez Botello; Gilberto Díaz-González; Claudia García-Ruelas

    2012-01-01

    Information is presented on the content of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in sediment cores collected in the coastal ecosystem of Laguna El Yucateco, located in the tropical southeastern Gulf of Mexico. The ecosystem lies in a region where the human population is socially and economically limited, and it is subjected to great environmental pressure derived mainly from the oil industry. The vertical profiles data s...

  2. Correlation and Fishers’ Perception in Selected Sites in Laguna de Bay, Luzon Island, Philippines

    Directory of Open Access Journals (Sweden)

    Arthur J. Lagbas

    2017-01-01

    Full Text Available White goby (Glossogobius giuris Hamilton 1822 is an omnivorous, native fish species which can be found in Laguna de Bay and its tributaries, and in other bodies of water in the Philippines. Deteriorating water quality, unsustainable fishing practices, aquaculture and predation by introduced invasive species are threatening the population of white goby and other native fish species in Laguna de Bay. This study was conducted to correlate select physico-chemical parameters of lake water and zooplankton abundance, and to assess white goby population based on fishers’ perception. Water samples were collected in three sites in June, September and December 2014. Twenty one zooplankton species belonging to 12 families were identified. The most abundant and frequently encountered zooplankton species is Eurytemora affinis Poppe 1880. Zooplanktons were most abundant in June and lowest in September. Key informant interviews with local fishers revealed that white goby population was abundant in April to August while catch report showed that fish catch is abundant in June and least during December. The fish abundance in April to June could be attributed to high productivity especially in summer season. The fishers perceived that the population of white goby was declining mainly due to water pollution, aquaculture, and predation by invasive alien species. A multi-stakeholder sustainable watershed management should be adapted to improve the water quality and extinction of native fish species in Laguna de Bay.

  3. Calidad y aprovechamiento del agua de la Laguna Unamuno (Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Vanesa Yael Bohn

    2004-01-01

    Full Text Available Una de las características más destacadas de la geomorfología de la provincia de Buenos Aires es la presencia de un número muy grande de lagunas, de tamaños y formas diversas, con una distribución aparentemente caótica. Muchas de ellas han ocupado tierras potencialmente productivas. La laguna Unamuno se halla localizada en la cuenca del arroyo Napostá Chico (1320 km2, en la región pampeana argentina. El objetivo del trabajo es el estudio de la calidad del agua de la laguna y el análisis de las posibilidades de aprovechamiento del recurso hídrico. Se recopilaron datos edafológicos y meteorológicos, se midieron parámetros físicos y se analizaron muestras de agua en superfi cie y profundidad. La calidad del agua es evaluada desde las perspectivas biológica, química y física.

  4. Hydrocarbon concentrations in sediments and clams (Rangia cuneata) in Laguna de Pom, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Legorreta, T.; Gold-Bouchot, G.; Zapata-Perez, O. [Unidad Merida (Mexico)

    1994-01-01

    Laguna de Pom is a coastal lagoon within the Laguna de Terminos system in southern Gulf of Mexico. It belongs to the Grijalva-Usumacinta basin, and is located between 18{degrees} 33{prime} and 18{degrees} 38{prime} north latitude and 92{degrees} 01{prime} and 92{degrees} 14{prime} west longitude, in the Coastal Plain physiographic Province of the Gulf. It is ellipsoidal and approximately 10 km long, with a surface area of 5,200 ha and a mean depth of 1.5 m. Water salinity and temperature ranges are 0 to 13 {per_thousand} and 25{degrees} to 31{degrees}C, respectively. Benthic macrofauna is dominated by bivalves such as the clams Rangia cuneata, R. flexuosa, and Polymesoda carolineana. These clams provide the basis of an artisanal fishery, which is the main economic activity in the region. The presence of several oil-processing facilities around the lagoon is very conspicuous, which together with decreasing yields has created social conflicts, with the fishermen blaming the mexican state oil company (PEMEX) for the decrease in the clam population. This work aims to determine if the concentration of hydrocarbons in the clams (R. cuneata) and sediments of Laguna de Pom are responsible for the declining clam fishery. 11 refs., 4 figs., 2 tabs.

  5. Subsidence and Extension Rates of Laguna Salada Basin, Northeastern Baja California, Mexico

    Science.gov (United States)

    Contreras, J.; Martin-Barajas, A.; Herguera, J. C.

    2002-12-01

    Laguna Salada basin in northeastern Baja California, Mexico, is an active half-graben product of the trans-tensional tectonics of the Gulf of California. It lies at the boundary between the North America and Pacific plates, 15 km west of the Cerro Prieto-Imperial fault system. We present the results of a time series analysis of the uppermost 980 m of a gamma ray log from the geothermal exploratory well ELS1 drilled in the proximity of the Laguna Salada fault, which bounds the basin on its eastern margin. Our analysis indicates its stratigraphy is cyclical and that the spectrum of the gamma ray log is similar to the spectrum of δ18O Pleistocene variations, which strongly suggest an orbital origin. Based on this, we establish a correlation between the gamma ray log and δ18O stages to constrain ages of sediments with an estimated uncertainty of ~10 kyr. We found that sedimentation rates at ELS1 site have remained constant during the last 780 kyr. The sedimentation rate at the ELS1 site is 1.6 mm/yr. This value is extrapolated to obtain the vertical and perpendicular to strike slip rates of Laguna Salada fault. It was found that the vertical slip component is 4.22 mm/yr and the perpendicular to strike slip component (E-W direction) is 1.55 mm/yr.

  6. Caldera La Peligrosa (47º15´S, 71°40´O: un evento clave en la Provincia Silícea Chon Aike

    Directory of Open Access Journals (Sweden)

    Patricia Sruoga

    2010-05-01

    Full Text Available En el área ubicada entre el lago Ghío y la sierra Colorada, en la Cordillera Patagónica Austral, aflora una secuencia piroclástico- lávica de carácter proximal correspondiente al Complejo El Quemado, de edad jurásica tardía. A partir del análisis integrado de litofacies y estructuras se llevó a cabo la reconstrucción de la arquitectura volcánica. Se han reconocido cuatro litofacies ignimbríticas y una litofacies lávico-hipabisal de composición riolítica, cuyo emplazamiento estuvo controlado por un sistema de fallas transtensionales de orientación NNO predominante. Se propone un modelo de evolución de la caldera La Peligrosa en tres etapas:1 pre-colapso, durante la cual se define una zona dilatante propicia para la formación de la caldera, con incipiente fallamiento en bloques, 2 colapso, cuando ocurre el emplazamiento de potentes ignimbritas cristalinas y megabrechas en una cubeta de subsidencia progresiva, controlada por un régimen transtensional con dirección de extensión NE y 3 post-colapso, durante la cual se produce el derrame de lavas junto con la intrusión de cuerpos dómicos, bajo condiciones de extensión oblicua con dirección de extensión NO. El pasaje de un ambiente transtensional a condiciones de extensión oblicua acompañó las últimas etapas del desarrollo de la caldera representando un notable cambio en las condiciones de la deformación en tiempos jurásicos. La formación y desarrollo de la caldera La Peligrosa puede ser considerada como un evento clave para entender los mecanismos eruptivos del vasto volcanismo ignimbrítico de la Provincia Silícea Chon Aike.

  7. Cinemática de la extensión jurásica vinculada a la Provincia Silícea Chon Aike, Santa Cruz, Argentina

    Directory of Open Access Journals (Sweden)

    María S. Japas

    2013-03-01

    Full Text Available La Provincia Silícea Chon Aike, de vasta distribución en Patagonia, plataforma continental y Península Antártica, representa un megaevento volcánico ocurrido en tiempos jurásicos (188-152 Ma, cuyo emplazamiento estuvo controlado por una tectónica extensional. El análisis cinemático llevado a cabo a partir de fallas y zonas de cizalla frágil-dúctil en cuatro localidades (El Dorado- Monserrat, Norte de Cerro Vanguardia y El Fénix, en la comarca del Deseado; y Lago Ghío, en la Cordillera Patagónica Austral, permitió definir los ejes cinemáticos de la deformación jurásica, reconocer dos eventos cinemáticos diferentes (principal y secundario e identificar la existencia de un régimen transtensional. En relación a la oblicuidad que presentan los ejes cinemáticos en estas localidades, se definieron en forma preliminar dos dominios: el oriental y el occidental. El dominio oriental (El Dorado - Monserrat, Norte de Cerro Vanguardia presenta una dirección de extensión ENE para el evento principal y NNO para el evento secundario, mientras que el dominio occidental (El Fénix y Lago Ghío exhibe direcciones de extensión NE y NO para los episodios principal y secundario, respectivamente. Estos eventos cinemáticos diferentes (principal y secundario guardan estrecha correlación con facies volcánicas definidas, ya que el episodio secundario se encuentra temporalmente restringido al momento del emplazamiento de la facies efusiva riolítica (domos, coladas, cuerpos hipabisales. Dado el marcado diacronismo de esta provincia volcánica, las diferencias estructurales y cinemáticas halladas entre ambos dominios podrían estar reflejando un emplazamiento controlado por estructuras desarrolladas progresivamente que, a escala continental, estarían vinculadas a un régimen de deformación no-coaxial mayor.

  8. The continuous improvement system of nuclear power plant of Laguna Verde; El sistema de mejora continua de la central nucleoelectrica Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Rivera C, A. [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Km. 42.5 Cardel-Nautla, Veracruz (Mexico)], e-mail: arr99999@cfe.gob.mx

    2009-10-15

    This paper describes the continuous improvement system of nuclear power plant of Laguna Verde and the achievements in implementing the same and additionally two study cases are presents. In February 2009 is noteworthy because the World Association of Nuclear Operators we identified as a learning organization, qualification which shows that the continuous improvement system has matured, and this system will expose as I get to learn to capitalize on our own experiences and external experiences diffused by the nuclear industry. In 2007 the management of nuclear power plants integrates its improvement systems and calls it continuous improvement system and is presented in the same extensive report that won the National Quality Award. This system is made up of 5 subsystems operating individually and are also related 1) human performance; 2) referential comparison or benchmarking; 3) self-assessment; 4) corrective action and 5) external operating experience. Five subsystems that plan, generate, capture, manage, communicate and protect the knowledge generated during the processes execution of nuclear power plant of Laguna Verde, as well as from external sources. The target set in 2007 was to increase the intellectual capital to always give response to meeting the security requirements, but creating a higher value to quality, customer, environment protection and society. In brief each of them, highlighting the objective, expectations management, implementation and some benefits. At the end they will describe two study cases selected to illustrate these cases as the organization learns by their continuous improvement system. (Author)

  9. Atmospheric emissions control at ENELVEN`s Ramon Laguna thermal power plant; Control de emisiones a la atmosfera en la central termoelectrica Ramon Laguna de ENELVEN

    Energy Technology Data Exchange (ETDEWEB)

    Rincon Rincon, Edis Rafael [Empresa de Servicio Electrico (ENELVEN), (Venezuela)

    1996-12-31

    ENELVEN is an electric utility that covers the areas of generation, transmission and distribution of the Western an South coast of the Maracaibo Lake of the Zulia State, Venezuela. General aspects of the Ramon Laguna of ENELVEN fossil power plant are presented, as well as the environmental measures implanted in this power station to avoid detrimental effects on the environment that could be caused by the emission of combustion products without the appropriate control, such as particulate matter, sulfur oxides, nitrogen oxides and carbon oxides [Espanol] ENELVEN es una empresa de servicio electrico que cubre las areas de generacion, transmision y distribucion de la Costa Occidental y Sur del Lago de Maracaibo, del Estado Zulia, Venezuela. Se presentan aspectos generales de la planta termoelectrica Ramon Laguna de la empresa ENELVEN, asi como las medidas ambientales implantadas en esta central para evitar efectos adversos sobre el ambiente que pudieran producirse por la emision de productos de la combustion si no existiera el debido control, tales como: particulas, oxidos de azufre, oxidos de nitrogeno y oxidos de carbono

  10. Botanical ecology and conservation of the Laguna de la Herrera (Sabana de Bogotá, Colombia Botanical ecology and conservation of the Laguna de la Herrera (Sabana de Bogotá, Colombia

    Directory of Open Access Journals (Sweden)

    Wijninga V. M.

    1989-09-01

    Full Text Available The acuatic, helophytic and pleustophytic vegetation of the Laguna de La Herrera, on the southwestern border of the high plain of Bogotá at 2550 m was studied following the Zurich- Montpellier approach. The communities recognized were: terrestrial community of Phytolacca bogotensis; helophytic communities of scirpus californicus and Typha angustifolia ; scirpus californicus ; Polygonum punctatum ; Rumex obtusifolius with Polygonum punctatum; Bidens laevis ; Hydrocotyle ranunculoides. Pleustophytic communities of Limnobium laevigatum; Azolla filiculoides with Lemna cf. gibba and Eichornia crassipes. The structure, floristic composition and ecological aspects were also considered. Several recommendations about conservation of the Laguna are given. Se estudió la vegetación alrededor de la Laguna de La Herrera, una laguna andina a 2550 m. Se diferenciaron una comunidad de Phytolacca bogotensis (1: comunidades helofíticas dominadas por: Scirpus californicus y Typha angustifolia (2; Scirpus californicus (3; Polygonum punctatum (4; Rumex obtusifolius y Polygonum punctatum (5; Bidens laevis (6; Hydrocotyle ranunculoides (7; comunidades pleustofíticas con: Limnobium laevigatum; (8; Azolla filiculoides y Lemna cf. gibba (9 y Eichhornia crassipes (10. Se registraron la estructura, composición florística, los rasgos ecológicos y la distribución de las comunidades y se comparó con la conductividad eléctrica y la calidad del agua. Finalmente, se hacen recomendaciones para la conservación de la laguna y la vegetación acuática.

  11. Subsidence of the Laguna Salada Basin, northeastern Baja California, Mexico, inferred from Milankovitch climatic changes

    Energy Technology Data Exchange (ETDEWEB)

    Contreras, Juan; Martin-Barajas, Arturo [Departamento de Geologia, CICESE, Ensenada Baja California (Mexico); Herguera, Juan Carlos [Division de Oceanologia, CICESE, Ensenada Baja California (Mexico)

    2005-01-15

    Laguna Salada in northern Baja California, Mexico, is an active half-graben product of the trans-tensional tectonics of the Gulf of California. It is sensitive to changes in sediment supply from the Colorado River basin. We present a time series analysis of the upper 980 m of a gamma-ray log from a borehole drilled near the Laguna Salada fault. The power spectrum of the gammaray log resembles the spectrum of {delta}{sup 1}8{omicron} Pleistocene isotopic variations from ice cores and from the deep ocean, known to be strongly controlled by Milankovitch cycles. We correlate {delta}{sup 1}8{omicron} stages with silty and sandy intervals in the log. Downcore ages for the last 780 ky are constrained within {approx}10 kyr. We derive a simple time vs. depth calibration relation for the basin over this time interval. Estimated sedimentation rates at the drill site appear to be constant with a value of {approx}1.6 mm/yr. We propose that this subsidence rate is produced by the Laguna Salada fault. [Spanish] La cuenca de Laguna Salada en el norte de Baja California, Mexico, es un semigraben activo producto de la tectonica ranstensional del Golfo de California. Esta cuenca endorreica es sensible a cambios en sedimentacion por variaciones en el aporte e sedimentos de fuentes cercanas y distales transportados por arroyos de las sierras adyacentes y por el Rio Colorado. Esta cuenca es un sitio excepcional para explorar el uso de cambios climaticos ciclicos como herramienta de datacion y estimar tasas de sedimentacion y subsidencia en el area. Para demostrar esto se presenta un analisis de series de tiempo de un registro de rayos de gama de un pozo geotermico exploratorio perforado adyacente a la falla de Laguna Salada, la cual limita el margen oriental de la cuenca. Los resultados del analisis indican que el espectro de los primeros 980 m del registro de rayos gama tiene una alta coherencia con el espectro de registros isotopicos paleoclimaticos de {delta}{sup 1}8{omicron} del

  12. Geología ambiental de la laguna de las Perdices, Monte, Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Nauris Dangavs

    2010-09-01

    Full Text Available El estudio de la laguna de las Perdices abarca tres aspectos: el geolimnológico, el geoambiental y el de remediación. El primero ha consistido en caracterizar el medio físico de un ambiente léntico típico de la Pampasia meridional prácticamente desconocido. El segundo, la evaluación del grado de deterioro natural y la contaminación físico-química y bacteriológica. El tercero propicia las medidas para su recuperación, máxime teniendo en cuenta que el Municipio de Monte pretende transformarla en Reserva Natural. Esta laguna de 11.50 km2, situada en el noreste bonaerense, pertenece a la cuenca de las Lagunas Encadenadas de Monte y fue evaluada con metodología geolimnológica, en base a cartografía, fotografía aérea e imágenes satelitales, nivelaciones, batimetría, freatimetría, perforaciones, muestreo de sedimentos, suelos y aguas. A tal efecto se caracterizaron los aspectos fisiográficos, geomorfológicos, geológicos e hidrológicos de la región y de la laguna. En la cubeta lagunar se estudiaron los depósitos colmatantes, integrados por siete unidades estratigráficas, de las cuales la de mayor interés corresponde a los depósitos actuales, indicadores directos del estado de degradación del ambiente. El régimen hidrológico de la laguna se estableció caracterizando las precipitaciones sobre la superficie lagunar, la evaporación, el escurrimiento superficial y freático, la freatimetría, la interrelación del cuerpo de agua con el agua subterránea, el balance hídrico anual y la dinámica acuática. Las aguas fueron evaluadas en los aspectos físico-químicos, estableciéndose su composición iónica y tipificación química según Maucha y la clasificación limnológica del ambiente acuático. Las determinaciones en agua y sedimentos confirmaron la severa contaminación físico-química y bacteriológica, incompatible con la vida acuática y el uso recreativo, de acuerdo a la normativa vigente. Dicha contaminaci

  13. Caldera La Peligrosa (47º15´S, 71°40´O: un evento clave en la Provincia Silícea Chon Aike La Peligrosa caldera (47°15´ 5,71°40´W: A key event in the siliceous province of Chon Aike

    Directory of Open Access Journals (Sweden)

    Patricia Sruoga

    2010-05-01

    Full Text Available En el área ubicada entre el lago Ghío y la sierra Colorada, en la Cordillera Patagónica Austral, aflora una secuencia piroclástico- lávica de carácter proximal correspondiente al Complejo El Quemado, de edad jurásica tardía. A partir del análisis integrado de litofacies y estructuras se llevó a cabo la reconstrucción de la arquitectura volcánica. Se han reconocido cuatro litofacies ignimbríticas y una litofacies lávico-hipabisal de composición riolítica, cuyo emplazamiento estuvo controlado por un sistema de fallas transtensionales de orientación NNO predominante. Se propone un modelo de evolución de la caldera La Peligrosa en tres etapas:1 pre-colapso, durante la cual se define una zona dilatante propicia para la formación de la caldera, con incipiente fallamiento en bloques, 2 colapso, cuando ocurre el emplazamiento de potentes ignimbritas cristalinas y megabrechas en una cubeta de subsidencia progresiva, controlada por un régimen transtensional con dirección de extensión NE y 3 post-colapso, durante la cual se produce el derrame de lavas junto con la intrusión de cuerpos dómicos, bajo condiciones de extensión oblicua con dirección de extensión NO. El pasaje de un ambiente transtensional a condiciones de extensión oblicua acompañó las últimas etapas del desarrollo de la caldera representando un notable cambio en las condiciones de la deformación en tiempos jurásicos. La formación y desarrollo de la caldera La Peligrosa puede ser considerada como un evento clave para entender los mecanismos eruptivos del vasto volcanismo ignimbrítico de la Provincia Silícea Chon Aike.In the area located between Ghío lake and sierra Colorada, in Cordillera Patagónica Austral, the Late Jurassic El Quemado Complex is represented by vent-facies of pyroclastic and lava origin. A reconstruction of the volcanic architecture has been carried out based on the integrated study of the lithofacies and the structures. Four ignimbritic

  14. Early alert system for oscillations detection applied to the Central of Laguna Verde; Sistema de alerta temprana para deteccion de oscilaciones aplicada a la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Calleros M, G.; Zapata Y, M.; Avila N, A.; Herrera H, S. F., E-mail: gcm9acpp@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Veder, Carretera Cardel-Nautla Km 42.5, Alto Lucero, Veracruz (Mexico)

    2011-11-15

    The code Early Alert System developed by Engineering of the Reactor of the nuclear power plant of Laguna Verde is presented, showing its reliability like preventive and corrective instrument to external interferences to the reactor core, due to equipment malfunction associated to the typical systems of a nuclear power plant, as those that control the reactor pressure, those that feed water to the reactor, those that control the valves of the main turbine. With this purpose, real cases of application of the System are shown where the results are compared with the independent evaluations carried out by the supplier, observing compatibility in both results. The benefits of the logarithm are discussed in the nuclear industry as soon as in non nuclear ambits. (Author)

  15. Negative sequence relay applied to generator 1 of the Laguna Verde nuclear power plant; Aplicacion de un relevador de secuencia negativa en el generador 1 de la central de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Diaz de la Serna P, Enrique [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    The rotor of a synchronous generator can be dangerously heated in a short time by stator current unbalance, therefore it must be protected with a specific relay. This article discusses the protection and the adjustments selected for Unit 1 of the Comision Federal de Electricidad Laguna Verde Nuclear Nuclear Power Station. [Espanol] El rotor de un generador sincrono puede calentarse peligrosamente en un tiempo corto debido a desbalance de corrientes en el estator, por lo que debe protegerse con un relevador especifico. En este articulo se describen la proteccion y los ajustes seleccionados para la unidad 1, de la central nucleoelectrica Laguna Verde de la Comision Federal de Electricidad.

  16. Contaminación producida por piscicultura intensiva en lagunas andinas de Junín, Perú

    Directory of Open Access Journals (Sweden)

    Mauro Mariano

    2011-05-01

    Full Text Available Se reportan los cambios producidos por el cultivo intensivo de la trucha Oncorhynchus mykiss en siete lagunas andinas. Las observaciones se realizaron en el año 1996, y entre el 2002 - 2007 y permitieron observar el proceso de deterioro de las lagunas, caracterizado por el incremento en las concentraciones de fosforo total y la disminución del oxigeno disuelto y la transparencia. La comunidad béntica fue evaluada en las siete lagunas en el 2007, resultando el número de especies y los índices de diversidad bajos (H'<1,26; <8 spp.. La abundancia varió entre 7 y 35 ind./0,04m2. La materia orgánica y carbonatos en fondo fueron altos (30,22 - 42,45%.

  17. Eficiencia del tratamiento de residuales porcinos en digestores de laguna tapada

    Directory of Open Access Journals (Sweden)

    D Blanco

    Full Text Available Se evaluó la eficiencia de dos lagunas tapadas, diseñadas para tratar los residuales de las granjas porcinas P-3 y T-2.1 _pertenecientes a la Asociación de Porcicultores de Yucatán, México_, con el objetivo de verificar la factibilidad de implementar en Cuba esta tecnología. Los indicadores físico-químicos y microbiológicos de los efluentes fueron determinados en el momento de su entrada y su salida de los digestores, y a su salida del lago de estabilización. El digestor de la granja P-3 logró remover más del 90 % de la demanda química de oxígeno (DQO y hasta el 71 % de los sólidos suspendidos totales (SST presentes; mientras que el digestor de la granja T-2.1 alcanzó una remoción del 78 % en la DQO y el 62 % de los SST. Los análisis sanitarios indicaron que las bacterias coliformes totales presentaron una disminución importante, de 2,4 x 108 a 1,7 x 103 en la granja P-3 y de 4,2 x 107 a 2,7 x 103 en la granja T-2.1. En ambas lagunas, los huevos de helmintos mostraron una reducción del 100 %. Se concluye que las lagunas tapadas tuvieron un adecuado desempeño en el tratamiento de los residuales porcinos, y que esta tecnología es factible de ser empleada en Cuba.

  18. Niebla ceruchis from Laguna Figueroa: dimorphic spore morphology and secondary compounds localized in pycnidia and apothecia.

    Science.gov (United States)

    Enzien, M; Margulis, L

    1988-01-01

    During and after the floods of 1979-80 Niebla ceruchis growing epiphytically on Lycium brevipes was one of the dominant aspects of the vegetation in the coastal dunal complex bordering the microbial mats at Laguna Figueroa, Baja California Norte, Mexico. The lichen on denuded branches of Lycium was far more extensively distributed than Lycium lacking lichen. Unusual traits of this Niebla ceruchis strain, namely localization of lichen compounds in the mycobiont reproductive structures (pycnidia and apothecia) and simultaneous presence of bilocular and quadrilocular ascospores, are reported. The abundance of this coastal lichen cover at the microbial mat site has persisted through April 1988.

  19. Bentos asociado al pastizal de Halodule (Potamogetonaceae) en Laguna de La Mancha, Veracruz, México

    OpenAIRE

    Reyes-Barragán, Ma del Pilar; Salazar-Vallejo, Sergio I.

    2016-01-01

    Se realizó un estudio puntual sobre la fauna asociada al pastizal de Halodule wrightii beaude t t eí en la Laguna de La Mancha, Veracruz, México, durante febrero, marzo, abril, junio, agosto, octubre, noviembre y diciembre de 1983 y febrero de 1984. Se pretendió detenninar la composición de la fauna béntica asociada al pasto y su variación estacional. Se efectuaron recolectas de material biológico y registros de parámetros ambientales (saliniudad, temperatura, profundidad del agua). La salini...

  20. Micobacteriosis en cercetas migratorias capturadas en lagunas del altiplano centro de México

    OpenAIRE

    Alicia E. Arrona-Rivera; Félix Sánchez-Godoy; Gary García-Espinosa

    2013-01-01

    Durante la inspección post mortem de las aves acuáticas migratorias cazadas durante la actividad cinegética correspondiente a la temporada invernal 2008-2009 en las lagunas del Altiplano centro de México, se detectaron nódulos firmes con contenido caseoso de color amarillo en el hígado de una cerceta ala azul (Anas discors) y una cerceta canela (Anas cyanoptera). A la histopatología con tinción de hematoxilina y eosina se observó exudado rodeado por células inflamatorias y tejido conectivo fi...

  1. Variaciones morfológicas en Blackfordia virginica (Hydroidomedusae: Blackfordiidae) en lagunas costeras de Chiapas, México

    OpenAIRE

    Carlos Álvarez Silva; Samuel Gómez Aguirre; Ma. Guadalupe Miranda Arce

    2003-01-01

    Blackfordia virginica es una hidromedusa importante en el zooplancton de lagunas costeras de México. Con el objeto de contribuir a su estudio se analizaron las variaciones morfológicas de esta especie en el sistema de lagunas costeras de Chiapas, México. Se estudiaron 503 ejemplares, sus tallas variaron de 6.1 a 9.9 mm de diámetro umbrelar; el número de tentáculos marginales varió de 86 a 125. Se reconocieron los sexos, 67.7% hembras y 30.2% machos. Solamente 31 medusas (26 hembras y cinco ma...

  2. The National Institute of Nuclear Research (ININ) and its participation in the External Radiological Emergency Plans at Laguna Verde Power plant; El ININ y su participacion en el Plan de Emergencia Radiologica Externo de la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, G. [Instituto Nacional de Investigaciones Nucleares, Departamento de Proteccion Radiologica, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1998-07-01

    In this article it is described the form in which the ININ participates in the External Radiological Emergency Plan at Laguna Verde Power plant. It is set the objective, mission and organization of this plan. The responsibilities and activities that plan has assigned are mentioned also the organization to fulfil them and the obtained results during 9 years of participation. (Author)

  3. Experience and results of modifications of systems power electric of Laguna Verde (Mexico); Experiencia y resultados de las modificaciones de los sistemas electricos de potencia de Laguna Verde (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Solorzano, J. J.; Gabaldon Martin, M.

    2011-07-01

    This paper describes the main findings and improvements in the Laguna Verde Nuclear Power Plant (Mexico), following the changes made to the systems electrical power thereof, derivatives of the Project of Increased Power. This project has been an increased power to 120% of the 2 units Plant, which has necessitated the replacement of major electric systems of power in Plant.

  4. Dynamic analysis of the condensate and of the feed water in the Laguna Verde nuclear power station; Analisis dinamico del sistema de condensado y agua de alimentacion de la nucleoelectrica de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Macedo Muth, Javier; Sandoval Pena, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    This article shows a non-lineal mathematical model for the condensate, and feed water systems and for feed water heater drains at the Laguna Verde Nuclear Power Station for its simulation in real time. The model allows the calculation of flows and pressures in all the piping system and equipment that integrate the systems. It was obtained by using the force unbalance in the fluid concept and is capable of reproducing its dynamic behavior through variations induced by the different operation modes and more common failures. The final model objective is to form part of the Laguna Verde simulator that will be used for operator training of this Nuclear Power Plant. [Espanol] En este articulo se muestra un modelo matematico no lineal de los sistemas de condensado, agua de alimentacion y drenes de calentadores de la central nuclear de Laguna Verde para su simulacion en tiempo real. El modelo permite calcular los flujos y las presiones en toda la red de tuberias y equipos que integran los sistemas. Se obtuvo utilizando el concepto de desbalance de fuerzas en el fluido, y es capaz de reproducir su comportamiento dinamico ante variaciones inducidas por los diversos modos de operacion y fallas mas comunes. El objetivo final del modelo es formar parte del simulador de Laguna Verde que se empleara para el adiestramiento de los operadores de dicha central nuclear.

  5. Environmental evidence of fossil fuel pollution in Laguna Chica de San Pedro lake sediments (Central Chile)

    Energy Technology Data Exchange (ETDEWEB)

    Chirinos, L. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile)]. E-mail: lchirin@pucp.edu.pe; Rose, N.L. [Environmental Change Research Centre, University College London, 26 Bedford Way, London WG1HOAP (United Kingdom); Urrutia, R. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile); Munoz, P. [Departamento de Biologia Marina, Universidad Catolica del Norte, Larrondo 1281, Coquimbo (Chile); Torrejon, F. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile); Torres, L. [Departamento de Botanica, Universidad de Concepcion, Concepcion (Chile); Cruces, F. [Departamento de Botanica, Universidad de Concepcion, Concepcion (Chile); Araneda, A. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile); Zaror, C. [Facultad de Ingenieria Quimica, Universidad de Concepcion, Concepcion (Chile)

    2006-05-15

    This paper describes lake sediment spheroidal carbonaceous particle (SCP) profiles from Laguna Chica San Pedro, located in the Biobio Region, Chile (36{sup o} 51' S, 73{sup o} 05' W). The earliest presence of SCPs was found at 16 cm depth, corresponding to the 1915-1937 period, at the very onset of industrial activities in the study area. No SCPs were found at lower depths. SCP concentrations in Laguna Chica San Pedro lake sediments were directly related to local industrial activities. Moreover, no SCPs were found in Galletue lake (38{sup o} 41' S, 71{sup o} 17.5' W), a pristine high mountain water body used here as a reference site, suggesting that contribution from long distance atmospheric transport could be neglected, unlike published data from remote Northern Hemisphere lakes. These results are the first SCP sediment profiles from Chile, showing a direct relationship with fossil fuel consumption in the region. Cores were dated using the {sup 21}Pb technique. - The lake sediment record of SCPs shows the record of fossil-fuel derived pollution in Central Chile.

  6. Water-quality reconnaissance of Laguna Tortuguero, Vega Baja, Puerto Rico, March 1999-May 2000

    Science.gov (United States)

    Soler-Lopez, Luis; Guzman-Rios, Senen; Conde-Costas, Carlos

    2006-01-01

    The Laguna Tortuguero, a slightly saline to freshwater lagoon in north-central Puerto Rico, has a surface area of about 220 hectares and a mean depth of about 1.2 meters. As part of a water-quality reconnaissance, water samples were collected at about monthly and near bi-monthly intervals from March 1999 to May 2000 at four sites: three stations inside the lagoon and one station at the artificial outlet channel dredged in 1940, which connects the lagoon with the Atlantic Ocean. Physical characteristics that were determined from these water samples were pH, temperature, specific conductance, dissolved oxygen, dissolved oxygen saturation, and discharge at the outlet canal. Other water-quality constituents also were determined, including nitrogen and phosphorus species, organic carbon, chlorophyll a and b, plankton biomass, hardness, alkalinity as calcium carbonate, and major ions. Additionally, a diel study was conducted at three stations in the lagoon to obtain data on the diurnal variation of temperature, specific conductance, dissolved oxygen, and dissolved oxygen saturation. The data analysis indicates the water quality of Laguna Tortuguero complies with the Puerto Rico Environmental Quality Board standards and regulations.

  7. Organochlorines and trace elements in four colonial waterbird species nesting in the lower Laguna Madre, Texas.

    Science.gov (United States)

    Mora, M A

    1996-11-01

    Eggs from four aquatic bird species nesting on the National Audubon Sanctuary Islands of the lower Laguna Madre were collected during 1993 and 1994 to determine concentrations of organochlorine compounds and trace metals and to evaluate their possible detrimental effects on birds nesting in this aquatic ecosystem. The only chlorinated hydrocarbons found above detection limits were p,p'-DDE (DDE), p,p'-DDT (DDT), HCB, HCH, chlordane, and polychlorinated biphenyls (PCBs). Median DDE and PCB levels in eggs of four species were below 1 microgram/g ww. Concentrations of DDE were much greater (6-70 fold) than the concentrations of other chlorinated pesticides which were present at or near detection limits. One egg from a snowy egret contained 9.65 micrograms/g DDE, 0.056 microgram/g DDD, and 1.75 micrograms/g DDT. Ten heavy metals and trace elements (Hg, Se, B, Cr, Cu, Fe, Mg, Mn, Sr, and Zn) were detected in 90% of the samples but at levels that were not of concern. In 1993-1994, concentrations of DDE in eggs of aquatic birds of the lower Laguna Madre were much lower than levels detected in this area during the late 1970s and early 1980s. Concentrations of DDE, PCBs, and trace metals in eggs detected in this study could not be associated with deformities or other detrimental effects on birds.

  8. Seagrasses, Dredging and Light in Laguna Madre, Texas, U.S.A.

    Science.gov (United States)

    Onuf, Christopher P.

    1994-07-01

    Light reduction resulting from maintenance dredging was the suspected cause of large-scale loss of seagrass cover in deep parts of Laguna Madre between surveys conducted in 1965 and 1974. Additional changes to 1988, together with an analysis of dredging frequency and intensity for different parts of the laguna, were consistent with this interpretation. Intensive monitoring of the underwater light regime and compilation of detailed environmental data for 3 months before and 15 months after a dredging project in 1988 revealed reduced light attributable to dredging in four of eight subdivisions of the study area, including the most extensive seagrass meadow in the study area. Dredging effects were strongest close to disposal areas used during this project but still were detectable on transects >1·2 km from the nearest dredge disposal area. In the subdivision of the study area where most of the dredge disposal occurred, light attenuation was increased throughout the 15 months of observation after dredging. In the seagrass meadow and the transition zone at the outer edge of the meadow, effects were evident up to 10 months after dredging. Resuspension and dispersion events caused by wind-generated waves are responsible for the propagation of dredge-related turbidity over space and time in this system.

  9. Water resources on the Pueblo of Laguna, west-central New Mexico

    Science.gov (United States)

    Risser, D.W.; Lyford, F.P.

    1983-01-01

    This study evaluates the quality and quantity of water available on the Pueblo of Laguna, New Mexico. Groundwater for public supply occurs in the valley fill along the Rio San Jose, in the Paguate and Encinal areas, and possibly in the northern part of the Sedillo Grant. The valley fill in the Rio San Jose will supply 50 to 450 gallons per minute of potable water to properly constructed wells. In the alluvium along Rio Paguate, additional development of as much as 250 gallons per minute is possible. Groundwater for irrigation is restricted by available yields and quality to the valley fill along the Rio San Jose and possibly the western part of the Major 's Ranch area. In the Rio San Jose valley yields of 50 to 450 gallons per minute of water containing 500 to 3,000 milligrams per liter are possible. Digital-model simulations of the valley-fill aquifer west of the Village of Laguna show a potential salvage of as much as 900 acre-feet per year of evapotranspiration losses if water levels are lowered. Model studies also indicate that the winter flow of the Rio San Jose could be used to recharge groundwater stored in the valley. (USGS)

  10. Winter distributions of North American Plovers in the Laguna Madre regions of Tamaulipas, Mexico and Texas, USA

    Science.gov (United States)

    Mabee, Todd J.; Plissner, Jonathan H.; Haig, Susan M.; Goossen, J.P.

    2001-01-01

    To determine the distribution and abundance of wintering plovers in the Laguna Madre of Texas and Tamaulipas, surveys were conducted in December 1997 and February 1998, along a 160 km stretch of barrier islands in Mexico and- 40 km of shoreline on South Padre Island, Texas. Altogether, 5,673 individuals, representing six plover species, were recorded during the surveys. Black-bellied Plovers Pluvialis squatarola were the most numerous (3 ,013 individuals) representing 53% of the total number of plovers observed. Numbers of Piping Charadriusm elodu, Snowy C . alexandrinus, Semipalmated C. semipalmatus and Wilson's Plovers C. wilsonia were 739, 1,345, 561, and 13 birds, respectively. Most individuals (97%) of all species except Wilson's Plovers were observed on bayside flats of the barrier islands. Similar numbers of Piping Plovers were recorded at South Padre Island, Texas, and in the Laguna Madre de Tamaulipas. Over 85% of the individuals of each of the other species were found in the more extensively surveyed Mexico portion of Laguna Madre. In Tamaulipas, most plover species were observed more often on algal flats than any other substrate. These results provide evidence of the value of these systems as wintering areas for plover species and indicate the need for more extensive survey efforts to determine temporal and spatial variation in the distribution of these species within the Laguna ecosystem.

  11. Late Neogene stratigraphy and tectonic control on facies evolution in the Laguna Salada Basin, northern Baja California, Mexico

    Science.gov (United States)

    Martín-Barajas, A.; Vázquez-Hernández, S.; Carreño, A. L.; Helenes, J.; Suárez-Vidal, F.; Alvarez-Rosales, J.

    2001-10-01

    The Laguna Salada Basin (LSB) in northeastern Baja California records late-Neogene marine incursions in the Salton Trough and progradation of the Colorado River delta. Early subsidence and subsequent tectonic erosion are related to evolution of the Sierra El Mayor detachment fault during late Miocene time (geothermal exploratory well on the eastern margin of LSB. Interfingering fluvial-sandstone deposits and prograding alluvial fanglomerates with coarse debris-flow and rock-avalanche deposits crudely mark the onset of vertical slip along the Laguna Salada fault and rapid uplift of Sierra Cucapa and Sierra El Mayor. Up to 2 km of Quaternary alluvial-fan and lacustrine deposits accumulated along the eastern margin of LSB, whereas lower subsidence rates produced a thinner sedimentary wedge over a ramp-like crystalline basement along the western margin. In early Pleistocene time (˜2-1 Ma), the Laguna Salada became progressively isolated from the Colorado River delta complex, and the Salton Trough by activity on the Elsinore and Laguna Salada fault zones.

  12. Asociación a sustratos de los erizos regulares (Echinodermata: Echinoidea) en la laguna arrecifal de Isla Verde, Veracruz, México

    OpenAIRE

    E.V. Celaya-Hernández; F.A. Solís-Marín; A. Laguarda-Figueras; A. de la L. Durán-González; T. Ruiz Rodríguez

    2008-01-01

    Se presenta el estudio de la diversidad, abundancia, distribución y asociación de sustrato de las especies de erizos regulares presentes en la parte Sur de la laguna arrecifal de Isla Verde, Veracruz, México. Se realizaron cuatro recolectas entre octubre del 2000 a octubre del 2002. Se seleccionó un cuadrante de muestreo, el más representativo, en la zona suroeste de la laguna arrecifal, con un área de 23 716 m2, asi mismo se muestreó en toda la parte sur de la laguna arrecifal. Las especies ...

  13. Economic analysis of extended cycles in the Laguna Verde nuclear power plant; Analisis economico de ciclos de extendidos en la Central Nucleoelectrica Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez N, H.; Hernandez M, J.L.; Francois L, J.L. [Facultad de Ingenieria, UNAM, 04510 Mexico D.F. (Mexico)]. E-mail: hermilo@correo.unam.mx

    2004-07-01

    The present work presents a preliminary analysis of economic type of extended cycles of operation of the Unit One in the Laguna Verde nuclear power plant. It is analysed an equilibrium cycle of 18 months firstly, with base to the Plan of Use of Energy of the Federal Commission of Electricity, being evaluated the cost of the energy until the end of the useful life of the plant. Later on an alternative recharge scenario is presented with base to an equilibrium cycle of 24 months, implemented to the beginning of the cycle 11, without considering transition cycles. It is added in both cycles the cost of the substitution energy, considering the unitary cost of the fuel of a dual thermoelectric power station of 350 M We and evaluating in each operation cycle, in both scenarios, the value of the substitution energy. The results show that a reduction of the days of recharge in the cycle of 24 months could make this option but favorable economically. The duration of the period of recharge rebounds in considerable grade in the cost of energy generation for concept of fuel. (Author)

  14. Optimization of the fuel use in the nuclear power plant of Laguna Verde; Optimizacion del uso de combustible en la Central Nuclear de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz S, J. J.; Castillo M, J. A.; Perusquia del Cueto, R., E-mail: juanjose.ortiz@inin.gob.m [ININ, Departamento de Sistemas Nucleares, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-07-01

    The fuel management in a nuclear power reactor for the electricity production has a main objective the efficient use of the nuclear fuel during the reactor operation, without to neglect the related with the security and to achieve the economic profitability in turn. The efficient use of the fuel implies to extract the maximum electric power of the uranium that the reactor security is guaranteed and provide economic benefits for the owner company of the nuclear reactor. In Mexico, the Federal Commission of Electricity have two boiling water reactors in the nuclear power plant of Laguna Verde (Veracruz, Mexico). In this nuclear power plant the operation of a nuclear reactor is carried out by means of operation cycles that have 18 months of duration at the moment. At the end of each cycle, the reactor stops to carry out the fuel recharge phase. The fuel assemblies can be removed or relocated in each cycle. Approximately a fourth part of the fuel assemblies are replaced by fresh fuels. This means that each fuel assemble remains, on the average, 4 cycles in the reactor or the order of six years. Therefore, the fuel management has for object to design the configuration of fuel load and form of reactor operation, so that the safety aspects are satisfied and that the expectations of electric generation are reached for each operation cycle of the useful life of the reactor. (Author)

  15. Reproduction of the flow-power map of the Laguna Verde power plant; Reproduccion del mapa flujo-potencia de la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Amador G, R.; Gonzalez M, V.M. [Comision Nacional de Seguridad Nuclear y Salvaguardias, 03000 Mexico D.F. (Mexico)

    1993-07-01

    The National Commission of Nuclear Safety and Safeguards (CNSNS) requires to have calculation tools which allows it to make analysis independent of the behavior of the reactor core of Laguna Verde nuclear power plant (CNLV) with the purpose to support the evaluation and discharge activities of the fuel recharges licensing. The software package Fms (Fuel Management System) allows to carry out an analysis of the core of the BWR type reactors along the operation cycle to detect possible anomalies and/or helping in the fuel management. In this work it is reproduced the flow-power for the CNLV using the Presto code of the Fms software package. The comparison of results with the map used by the operators of CNLV shows good agreement between them. Another exercise carried out was the changes study that the axial and radial power outlines undergo as well as the thermohydraulic parameters (LHGR, APLHGR, CPR) when moving a control rod. The obtained results show that is had the experience to effect analysis of the reactor behavior using the Presto-Fms code therefore the study of the rest of the software package for the obtention of nuclear parameters used in this code is recommended. (Author)

  16. Implementation of the project of equipment reliability in the nuclear power plant of Laguna Verde; Implementacion del proyecto de confiabilidad de equipo en la Central Nucleoelectrica Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Rios O, J. E.; Martinez L, A. G. [CFE, Central Laguna Verde, Subgerencia General de Operacion, Veracruz (Mexico)]. e-mail: jrios@cfe.gob.mx

    2008-07-01

    A equipment is reliable if it fulfills the function for which was designed and when it is required. To implement a project of reliability in a nuclear power plant this associate to a process of continuous analysis of the operation, of the conditions and faults of the equipment. The analysis of the operation of a system, of the equipment of the same faults and the parts that integrate to equipment take to identify the potential causes of faults. The predictive analysis on components and equipment allow to rectify and to establish guides to optimize the maintenance and to guarantee the reliability and function of the same ones. The reliability in the equipment is without place to doubts a wide project that embraces from the more small component of the equipment going by the proof of the parts of reserve, the operation conditions until the operative techniques of analysis. Without place of doubt for a nuclear power plant the taking of decisions based on the reliability of their systems and equipment will be the appropriate for to assure the operation and reliability of the same one. In this work would appear the project of reliability its processes, criteria, indicators action of improvement and the interaction of the different disciplines from the Nuclear Power Plant of Laguna Verde like a fundamental point for it put in operation. (Author)

  17. INTERAKSI TROFIK JUVENIL IKAN DAN UDANG DI LAGUNA SEGARA ANAKAN, CILACAP

    Directory of Open Access Journals (Sweden)

    Didik Wahju Hendro Tjahjo

    2016-05-01

    Full Text Available Segara Anakan mempunyai peran penting sebagai kawasan pengelolaan sumber daya ikan dan udang. Beberapa jenis ikan dan udang menggunakan laguna ini sebagai daerah asuhan. Penelitian dengan tujuan untuk mengetahui aspek biologi juvenil ikan dan udang dalam memanfaatkan sumber daya makanan alami dilakukan di perairan laguna Segara Anakan Kabupaten Cilacap pada tahun 2010. Pengambilan sampel dilakukan dengan menggunakan metode tersratifikasi dengan menetapkan 9 stasiun pengamatan. Analisis data meliputi kebiasaan makan, tingkat trofik, luas relung serta interaksi juvenile ikan dan udang dalam memanfaatkan sumber daya makanan alami. Hasil analisis kebiasaan makan menunjukkan bahwa juvenil ikan dan udang dapat dikelompokan menjadi tiga tingkatan trofik yaitu herbivora (2,00 – 2,50, omnivora (2,51 – 3,00 dan karnivora (3,01 – 3,50.  Luas relung makanan juvenil ikan dan udang adalah relatif sempit atau bersifat spesialis dengan nilai indeks berkisar antara 1,00 – 3,02. Hasil analisis kesamaan dalam pemanfaatan sumber daya makanan menunjukkan bahwa interaksi antar jenis ikan dan udang relatif rendah, sehingga peluang terjadinya kompetisi antar jenis rendah. Kondisi ini dapat diartikan bahwa ketersediaan makanan alami di perairan laguna tidak menjadi faktor pembatas.   Segara Anakan loogon plays an important role as the management area of fish and shrimp resources. Several species of fish and shrimp use this lagoon as an area of nursery ground. A research aimed to investigate the biological aspects of juvenile fish and shrimps in the utilization of natural food resources. Have been conductcd in the lagoon of Segara Anakan, Cilacap District in 2010. Sampling was done by using a stratification method with 9 research stations. Food habits, trophic level, niche width and interactions in the utilization of natural food resources were analyzed. Results showed that the juveniles of fish and shrimp could be grouped into three trophic levels i

  18. Trace metal partitioning in Thalassia testudinum and sediments in the Lower Laguna Madre, Texas.

    Science.gov (United States)

    Whelan, Thomas; Espinoza, Jorge; Villarreal, Xiomara; Cottagoma, Maria

    2005-01-01

    Seagrass communities dominate the Laguna Madre, which accounts for 25% of the coastal region of Texas. Seagrasses are essential to the health of the Laguna Madre (LM) and have experienced an overall decline in coverage in the Lower Laguna Madre (LLM) since 1967. Little is known on the existing environmental status of the LLM. This study focuses on the trace metal chemistry of four micronutrient metals, Fe, Mn, Cu, and Zn, and two non-essential metals, Pb and As, in the globally important seagrass Thalassia testudinum. Seasonal trends show that concentrations of most essential trace metals increase in the tissue during the summer months. With the exception of (1) Cu in the vertical shoot and root, and (2) Mn in the roots, no significant positive correlation exists between the rhizosphere sediment and T. testudinum tissue. Iron indicates a negative correlation between the morphological units and the rhizosphere sediments. No other significant relationship was found between the sediments and the T. testudinum tissue. Mn was enriched up to 10-fold in the leaf tissue relative to the other morphological units and also enriched relative to the rhizosphere sediments. Both Cu and Mn appear to be enriched in leaf tissue compared to other morphological units and also enriched relative to the Cu and Mn in the rhizoshpere sediments. Sediments cores taken in barren areas were slightly elevated in Zn relative to the rhizosphere sediments, whereas no other metals showed statistical differences between barren sediment cores and rhizosphere sediments. However, no correlation was measured in T. testudinum tissue and Zn in rhizosphere sediments. Previous studies suggested that Fe/Mn ratios could indicate differences between seagrass environments. Our results indicate that there is an influence from the Rio Grande in the Fe/Mn signature in sediments, and that ratio is not reflected in the T. testudinum tissue. The results from this study show that the LLM contains trace metal

  19. Proposal - Mapping of Six Federally Endangered Listed Plants and Surveying the Population Status of Eugenia woodburyana at La Tinaja, Laguna Cartagena National Wildlife Refuge. Lajas, Puerto Rico

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This proposal concerns the distribution and relative abundance of 5 federally endangered plants endemic to Puerto Rico and specifically on Laguna Cartagena National...

  20. Propuestas para el Programa Integral de Manejo y desarrollo del parque Nacional Lagunas de Montebello

    Directory of Open Access Journals (Sweden)

    Carlos Melo G.

    1986-01-01

    Full Text Available El Gobierno mexicano ha establecido un nuevo programa de manejo y protección ecológica. Este programa, denominado Sistema Nacional de Áreas Naturales Protegidas, pretende establecer una revisión crítica de los objetivos, manejo, formas de administración, y problemas en el uso del suelo, aspectos que son comunes en el sistema de parques nacionales; todo ello, con el fin de lograr establecer una forma óptima para su uso y manejo. El presente trabajo contiene una proposición nueva para el uso del suelo del parque nacional Lagunas de Montebello, Chiapas. Esta propuesta contiene innovaciones metodológicas para optimizar la utilización y conservación del paisaje y sus recursos, de acuerdo con las recomendaciones que la FAO ha dado para los países latinoamericanos.

  1. Remote sensing and numerical modeling of suspended sediment in Laguna de Terminos, Campeche, Mexico

    Science.gov (United States)

    Jensen, John R.; Kjerfve, Bjorn; Ramsey, Elijah W., III; Magill, Karen E.; Medeiros, Carmen

    1989-01-01

    It is necessary to understand the complex physical processes at work in coastal lagoons in order to manage them effectively. Improved methods of data collection and analysis must be found to provide synoptic, timely hydrodynamic information because of the sheer size of some lagoons and the difficulty of acquiring in situ data (particularly in the tropics). This paper summarizes research to model salinity and suspended sediment distributions in Laguna de Terminos, Mexico, using (1) a coupled hydrodynamic and dispersion model and (2) analysis of two Landsat Thematic Mapper images collected on November 25, 1984 and April 24, 1987. Atmospherically corrected chromaticity data derived from Thermatic Mapper data were significantly correlated with modeled total suspended sediment concentrations for the two dates. Comparison between numerically modeled and remotely sensed suspended sediment maps at 1.5 x 1.5 km resolution yielded a covariation map useful for identifying areas of discrepancy between the remotely sensed data and model output.

  2. Response of shoal grass, Halodule wrightii, to extreme winter conditions in the Lower Laguna Madre, Texas

    Science.gov (United States)

    Hicks, D.W.; Onuf, C.P.; Tunnell, J.W.

    1998-01-01

    Effects of a severe freeze on the shoal grass, Halodule wrightii, were documented through analysis of temporal and spatial trends in below-ground biomass. The coincidence of the second lowest temperature (-10.6??C) in 107 years of record, 56 consecutive hours below freezing, high winds and extremely low water levels exposed the Laguna Madre, TX, to the most severe cold stress in over a century. H. wrightii tolerated this extreme freeze event. Annual pre- and post-freeze surveys indicated that below-ground biomass estimated from volume was Unaffected by the freeze event. Nor was there any post-freeze change in biomass among intertidal sites directly exposed to freezing air temperatures relative to subtidal sites which remained submerged during the freezing period.

  3. Late Pleistocene-early Holocene karst features, Laguna Madre, south Texas: A record of climate change

    Energy Technology Data Exchange (ETDEWEB)

    Prouty, J.S. [Texas A& M Univ., Corpus Christi, TX (United States)

    1996-09-01

    A Pleistocene coquina bordering Laguna Madre, south Texas, contains well-developed late Pleistocene-early Holocene karst features (solution pipes and caliche crusts) unknown elsewhere from coastal Texas. The coquina accumulated in a localized zone of converging longshore Gulf currents along a Gulf beach. The crusts yield {sup 14}C dates of 16,660 to 7630 B.P., with dates of individual crust horizons becoming younger upwards. The karst features provide evidence of regional late Pleistocene-early Holocene climate changes. Following the latest Wisconsinan lowstand 18,000 B.P. the regional climate was more humid and promoted karst weathering. Partial dissolution and reprecipitation of the coquina formed initial caliche crust horizons; the crust later thickened through accretion of additional carbonate laminae. With the commencement of the Holocene approximately 11,000 B.P. the regional climate became more arid. This inhibited karstification of the coquina, and caliche crust formation finally ceased about 7000 B.P.

  4. Micobacteriosis en cercetas migratorias capturadas en lagunas del altiplano centro de México

    Directory of Open Access Journals (Sweden)

    Alicia E. Arrona-Rivera

    2013-01-01

    Full Text Available Durante la inspección post mortem de las aves acuáticas migratorias cazadas durante la actividad cinegética correspondiente a la temporada invernal 2008-2009 en las lagunas del Altiplano centro de México, se detectaron nódulos firmes con contenido caseoso de color amarillo en el hígado de una cerceta ala azul (Anas discors y una cerceta canela (Anas cyanoptera. A la histopatología con tinción de hematoxilina y eosina se observó exudado rodeado por células inflamatorias y tejido conectivo fibroso. La tinción de Ziehl-Neelsen evidenció la presencia de bacilos rectos o curvos. Este reporte muestra la presencia de Micobacteriosis en cercetas silvestres migratorias en México y resalta la necesidad de vigilar las enfermedades presentes en aves silvestres y su posible impacto en salud pública.

  5. Shallow sublittoral benthic communities of the Laguna Estuarine System, South Brazil

    Directory of Open Access Journals (Sweden)

    Gustavo Fonseca

    2006-03-01

    Full Text Available Sediment properties, microphytobenthos biomass (chlorophyll a and phaeopigments, and the structure of the benthic communities of the three main lagoons (Mirim, Imaruí and Santo Antonio of the Laguna Estuarine System, South Brazil, were analyzed during summer and winter. Microphytobenthos biomass did not differ significantly among the lagoons, but showed higher values in the summer. The macrofauna was characterized by low species richness and the dominance of the gastropod Heleobia australis, the tanaidean Kalliapseudes schubartti and the bivalve Erodona mactroides. The meiofauna was composed of 20 higher taxa and the nematodes dominated in all the lagoons and periods. Desmodora (Desmodora sp.1, Terschllingia sp. and Microlaimus sp. were numerically the most important among the 74 nematode species registered. This study showed that, in the Laguna Estuarine System, differences in the benthos among lagoons and periods were dependent on the fauna component analyzed. Whilst macrofauna and nematodes were significantly more diverse in the inner stations, in the Mirim Lagoon, the number of meiofauna taxa did not differ significantly among the lagoons and the diversity and evenness were highest in Santo Antonio. These results were a response of the fauna to the salinity oscillations coupled with the heterogeneity of the sediment in the lagoons. The temporal variability of the fauna, macrofauna being more abundant in the summer and meiofauna in the winter, could be related to the different life strategies of these groups.Propriedades do sedimento, biomassa microfitobêntica (clorofila a e feopigmentos, e a estrutura das comunidades bênticas das três principais lagoas (Mirim, Imaruí e Santo Antonio do Sistema Estuarino de Laguna, sul do Brasil, foram analisadas durante o verão e inverno. A biomassa microfitobêntica não diferiu significativamente entre as lagoas, mas seus valores foram maiores no verão. A macrofauna foi caracterizada pela baixa

  6. Helminth parasites in Chaunus marinus and Cranopis valliceps (Anura: Bufonidae) from Lagunas Yalahau, Yucatan, Mexico.

    Science.gov (United States)

    Espínola-Novelo, Juan Francisco; Guillén-Hernández, Sergio

    2008-06-01

    Eight helminth taxa were found parasitizing Chaunus marinus (n = 40) and Cranopsis valliceps (n = 40) from the Parque Estatal Lagunas Yalahau, Yucatan, Mexico. Seven taxa (2 digeneans: Langeronia macrocirra, Mesocoelium monas; 1 acanthocephalan: Oncicola sp.; 3 nematodes: Rhabdias füleborni, Aplectana itzocanensis, Cruzia morleyi; and a nematode larva) were found in C. marinus, while 4 taxa (all nematodes: Rhabdias fuelleborni, Aplectana itzocanensis, Ozwaldocruzia sp., and a nematode larva) were present in C. valliceps. Nematodes, particularly A. iztocanensis, showed high prevalence, mean abundance, and mean intensity values for both species of amphibians. The occurrence of R. fuelleborni, M. monas, L. macrocirra, and C. morleyi in these amphibians from the Yucatan Peninsula confirms their neotropical distribution, while the presence of A. itzocanensis increases its geographical distribution, suggesting a preference by neotropical, rather than neartic areas.

  7. Ostracode Paleoecology and Trace Element Shell Chemistry: A case study from Laguna Salada, Baja California, Mexico.

    Science.gov (United States)

    Romero-Mayen, V.; Bernal, J.; Palacios-Fest, M.; Carreno, A.

    2007-05-01

    The Laguna Salada Basin in northeastern Baja California constitutes the southwestern limit of the Salton Trough and provides insights into the evolution of marine and non-marine sedimentary basins during the latest Neogene at the head of the Gulf of California. A 43 m long core (LS04-1) recovered from the Basin consisted of alternating clay, silt and sand beds with gypsum lenses. Three radiocarbon dates provided the age control: 41,520±790 cal years BP at 30.21 m, 25,590±320 cal years BP at 26.60 m and 15,150±70 cal years BP at 7.50 m. A total of 103 samples were analyzed for taxonomy, taphonomy and geochemistry. Eighteen marine and brackish- water ostracode species and nine benthic foraminifera species were identified. Faunal changes suggest variations in the water source with the opening of the basin to the Gulf of California. The Mg/Ca and Sr/Ca ratios of valves of two ostracode species (Limnocythere staplini and Cyprideis castus) were measured using ICPMS. Based on the Mg/Ca ratios, water paleotemperatures were estimated using a regression model. Shell chemistry shows mixed results. Some intervals fit an acceptable range, whereas other are unrealistic. Analysis of Sr/Ca ratios ostracode valves from the conflicting horizons show evidence of diagenetic effects. The fossil assemblages indicate two dry periods: prior to the 41,520 cal years BP and after the 15 ,150 cal years BP, with the maximum highstand of the basin between 25,590 and 15,150 cal years BP. Given the diagenetic effects at Laguna Salada, ostracode shell chemistry paleotemperature estimates may not be warranted in attempting to determine this parameter from the dry periods shown by faunal assemblages.

  8. Thermal limits validation of gamma thermometer power adaption in CFE Laguna Verde 2 reactor core

    Energy Technology Data Exchange (ETDEWEB)

    Cuevas V, G.; Banfield, J. [GE-Hitachi Nuclear Energy Americas LLC, Global Nuclear Fuel, Americas LLC, 3901 Castle Hayne Road, Wilmingtonm, North Carolina (United States); Avila N, A., E-mail: Gabriel.Cuevas-Vivas@ge.com [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km 42.5, Alto Lucero, Veracruz (Mexico)

    2016-09-15

    This paper presents the status of GEH work on Gamma Thermometer (GT) validation using the signals of the instruments installed in the Laguna Verde Unit 2 reactor core. The long-standing technical collaboration between Comision Federal de Electricidad (CFE), Global Nuclear Fuel - Americas LLC (GNF) and GE-Hitachi Nuclear Energy Americas LLC (GEH) is moving forward with solid steps to a final implementation of GTs in a nuclear reactor core. Each GT is integrated into a slightly modified Local Power Range Monitor (LPRM) assembly. Six instrumentation strings are equipped with two gamma field detectors for a total of twenty-four bundles whose calculated powers are adapted to the instrumentation readings in addition to their use as calibration instruments for LPRMs. Since November 2007, the six GT instrumentation strings have been operable with almost no degradation by the strong neutron and gamma fluxes in the Laguna Verde Unit 2 reactor core. In this paper, the thermal limits, Critical Power Ratio (CPR) and maximum Linear Heat Generation Rate (LHGR), of bundles directly monitored by either Traverse In-core Probes (TIPs) or GTs are used to establish validation results that confirm the viability of TIP system replacement with automatic fixed in-core probes (AFIPs, GTs, in a Boiling Water Reactor. The new GNF steady-state reactor core simulator AETNA02 is used to obtain power and exposure distribution. Using this code with an updated methodology for GT power adaption, a reduced value of the GT interpolation uncertainty is obtained that is fed into the LHGR calculation. This new method achieves margin recovery for the adapted thermal limits for use in the Economic Simplified Boiling Water Reactor (ESBWR) or any other BWR in the future that employs a GT based AFIP system for local power measurements. (Author)

  9. BIOCHEMICAL, NUTRIENT AND INHIBITORY CHARACTERISTICS OF STREPTOMYCES CULTURED FROM A HYPERSALINE ESTUARY, THE LAGUNA MADRE (TEXAS

    Directory of Open Access Journals (Sweden)

    Luis E. Espinoza

    2013-01-01

    Full Text Available Streptomyces are common soil bacteria that produce secondary metabolites, including several antibiotics; however, the characteristics of marine Streptomyces are largely unknown. Sediment samples were taken from 3 sites in the Laguna Madre to isolate marine Streptomyces. Sediment was diluted, spread onto synthetic seawater media to estimate the total bacterial density of the samples and spread onto starch casein agar to isolate Streptomyces. Isolated Streptomyces were tested for salinity tolerance and optimal growth pH. Isolates were assayed using API 20E® test strips and BIOLOG™ plates to construct biochemical profiles and assess nutrient utilization abilities of the bacteria, respectively. Individual Streptomyces were tested for the ability to inhibit the growth of other isolated Streptomyces (i.e., interference competition and putatively identified by DNA sequencing. Results showed that there was no significant difference in microbial density in sediments from the 3 sampling sites. Eleven (11 Streptomyces pure cultures were obtained in total; most tolerated salinity up to 60 ppt and grew optimally at pH 7.5. Biochemical profile comparisons showed that the Streptomyces were only at least 74% similar; most (8/11 were >90% similar. Isolates could use between 87-95 carbon sources. Three (3 isolates displayed interference toward other isolates. Ten (10 isolates were identified as Streptomyces griseus by DNA sequencing. Laguna Madre Streptomyces organisms display some diverse characteristics with regards to their halotolerance, biochemical profiles, carbon source utilization and inhibition toward other organisms. Further investigations may yield greater understanding of these organisms in this and other marine environments and may be a reservoir of novel microorganisms and secondary metabolites.

  10. Implementacion de modulos constructivistas que atiendan "misconceptions" y lagunas conceptuales en temas de la fisica en estudiantes universitarios

    Science.gov (United States)

    Santacruz Sarmiento, Neida M.

    Este estudio se enfoco en los "misconception" y lagunas conceptuales en temas fundamentales de Fisica como son Equilibrio Termodinamico y Estatica de fluidos. En primer lugar se trabajo con la identificacion de "misconceptions" y lagunas conceptuales y se analizo en detalle la forma en que los estudiantes construyen sus propias teorias de fenomenos relacionados con los temas. Debido a la complejidad en la que los estudiantes asimilan los conceptos fisicos, se utilizo el metodo de investigacion mixto de tipo secuencial explicativo en dos etapas, una cuantitativa y otra cualitativa. La primera etapa comprendio cuatro fases: (1) Aplicacion de una prueba diagnostica para identificar el conocimiento previo y lagunas conceptuales. (2) Identificacion de "misconceptions" y lagunas del concepto a partir del conocimiento previo. (3) Implementacion de la intervencion por medio de modulos en el topico de Equilibrio Termodinamico y Estatica de Fluidos. (4) Y la realizacion de la pos prueba para analizar el impacto y la efectividad de la intervencion constructivista. En la segunda etapa se utilizo el metodo de investigacion cualitativo, por medio de una entrevista semiestructurada que partio de la elaboracion de un mapa conceptual y se finalizo con un analisis de datos conjuntamente. El desarrollo de este estudio permitio encontrar "misconceptions" y lagunas conceptuales a partir del conocimiento previo de los estudiantes participantes en los temas trabajados, que fueron atendidos en el desarrollo de las distintas actividades inquisitivas que se presentaron en el modulo constructivista. Se encontro marcadas diferencias entre la pre y pos prueba en los temas, esto se debio al requerimiento de habilidades abstractas para el tema de Estatica de Fluidos y al desarrollo intuitivo para el tema de Equilibrio Termodinamico, teniendo mejores respuestas en el segundo. Los participantes demostraron una marcada evolucion y/o cambio en sus estructuras de pensamiento, las pruebas estadisticas

  11. CARACTERIZACIÓN SOCIO-AMBIENTAL DE UN PAISAJE TRANSFORMADO: EL CASO DE LA LAGUNA NEGRA.TRELEW. CHUBUT. ARGENTINA

    Directory of Open Access Journals (Sweden)

    Gladys Alcarraz

    2008-12-01

    Full Text Available La ciudad de Trelew se encuentra en la Provincia del Chubut, departamento Rawson, a los 43o 14' de Latitud Sur y 65o 19' de Longitud Oeste, su Ejido Municipal cubre una superficie total de 248 km2. Aproximadamente el 70% de los líquidos cloacales domiciliarios y pluviales de la ciudad de Trelew, son vertidos desde principios de la década del 70’ a un sistema lagunar. Originalmente estas lagunas eran cuencas naturales, algunas permanentes y otras temporarias, alimentadas por aguas subterráneas y por precipitaciones. Los bajos, hoy convertidos en lagunas permanentes, hidrológicamente representaban áreas de descarga -evaporación- alimentadas por los aportes de cañadones que drenan desde la terraza intermedia y el valle o bien por crecientes y desbordes del Río Chubut. Hoy el proceso se ha revertido, y las lagunas aportan agua en forma constante al sistema freático, habiéndose convertido entonces, en áreas de recarga -infiltración-, con consecuencias ambientales, paisajísticas y sociales. El objetivo del presente trabajo fue determinar la variación multitemporal de las lagunas de estabilización de la ciudad de Trelew, desde los años 1969 a 2005 para estimar las consecuencias producidas en el paisaje y caracterizar social y económicamente la población aledaña a las lagunas. Metodológicamente, para caracterizar el área de estudio y realizar una evolución de la misma desde las características originales hasta la actualidad se utilizó la teledetección y un relevamiento censal a campo con aplicación de encuestas y observación directa. La población aledaña a las lagunas presenta características particulares en cuanto a las actividades económicas que desarrollan, las condiciones en las que viven y llevan adelante esas actividades, conformando “asentamientos aislados”, precarios, que le dan cierto carácter de espacio rural marginal, como categoría en el continuo rural-urbano. Cuando se cambian artificialmente las

  12. El Lago Chasicó: analogías y diferencias con las lagunas pampásicas.

    Directory of Open Access Journals (Sweden)

    Alejandra Vanina Volpedo

    2013-10-01

    Full Text Available La llanura pampeana es una de las grandes planicies a nivel mundial. La escasa pendiente y la geomorfología hacen que el escurrimiento de las aguas de  lluvia, sea relativamente lento y presente numerosos sistemas lénticos, que poseen diferentes orígenes geomorfológicos y características limnológicas. En este trabajo se comparan las características más relevantes de los sistemas lénticos más comunes presentes en la zona (lagunas pampásicas y se  analizan las analogías y diferencias de dichos cuerpos de agua con  un lago del sudoeste bonaerense (Lago Chasicó.  Las lagunas pampásicas poseen un perfil de “palangana”, no poseen un ciclo térmico definido, ni estratificación persistente,  poseen circulación continua, y no presentan una diferenciación entre la zona litoral y la central de la laguna. Otra de las características típicas de estos cuerpos de agua es la presencia de macrófitas. El Lago Chasicó posee un origen geomorfológico combinado tectónico-eólico, perfil en forma de “U” y una profundidad importante, significativamente mayor a la profundidad media de las lagunas pampásicas. Esta característica permite sugerir la posibilidad de la existencia de un gradiente térmico. Además no posee macrofitas en su costa. Las aguas del lago son  clorurada sódicas, poseen alta salinidad (>25 gL-1, mientras que las aguas de las lagunas pampásicas son bicarbonatadas sódicas o cloruradas sódicas bicarbonatadas, sin anión dominante, con una salinidad menor a 3 g L-1. El Lago Chasicó y las lagunas pampásicas son hipertróficos.

  13. Lacustrine evidence of anti-phase distribution of moisture in Southern South America during the Neoglacial period (Invited)

    Science.gov (United States)

    Piovano, E.; Ariztegui, D.; Sylvestre, F.; Córdoba, F.

    2009-12-01

    An increasing number of lacustrine records is now available for southern South America east of the Andes. As a result a network of well-studied sites is emerging allowing to track hydrological changes throughout time at a regional scale. New limnogeological results spanning the Holocene across the subtropical Pampean plains of Southern South America are compared with lacustrine records covering both Andean and extra Andean sectors of eastern Patagonia. The development of contrasting hydrological patterns can be observed between the Pampas (Laguna Mar Chiquita, 30°S; Laguna Melincué, 34°S; Lagunas Encadenadas del Oeste de Buenos Aires, 37°S) and eastern Patagonia (Lago Frías, 41°S; Lago Cardiel, 49°S; and Laguna Potrok Aike, 52°S) at both sides of the South American Arid Diagonal (AD) during prevailing warm or cold climatic phases, respectively. Paleohydrological reconstructions suggest wet conditions in regions located west and south of the AD, like Patagonia or even the Central Andes, during cold climatic phases such as those occurred during neoglaciations including the Little Ice Age (LIA). These phases are characterized by a dominant Pacific source of moisture. Conversely, dry conditions can be proposed for the same climatic interval across the subtropical low-lands east of the AD. These areas are mostly under the influence of an Atlantic summer rain regime. Conversely, extensive dryness across Patagonia and wet conditions in the Pampas can be inferred during warm climatic phases such as the Medieval Climatic Anomaly or the last part of the 20th century. This new paleohydrological data from Patagonia and the Pampean plains further indicate that the development of this anti-phase hydrological pattern was active only after the middle Holocene. Thus, it appears as contemporaneous to an intensification of the Southern Westerlies in concert with a weakened Monsoonal circulation. The anti-phasing cold/wet vs. cold/dry hydrological conditions at different

  14. Analysis of internal events for the Unit 1 of the Laguna Verde Nuclear Power Station. Appendixes; Analisis de eventos internos para la Unidad 1 de la Central Nucleoelectrica de Laguna Verde. Apendices

    Energy Technology Data Exchange (ETDEWEB)

    Huerta B, A.; Lopez M, R. [Comision Nacional de Seguridad Nuclear y Salvaguardias, 03000 Mexico D.F. (Mexico)

    1995-07-01

    This volume contains the appendices for the accident sequences analysis for those internally initiated events for Laguna Verde Unit 1, Nuclear Power Plant. The appendix A presents the comments raised by the Sandia National Laboratories technical staff as a result of the review of the Internal Event Analysis for Laguna Verde Unit 1 Nuclear Power Plant. This review was performed during a joint Sandia/CNSNS multi-day meeting by the end 1992. Also included is a brief evaluation on the applicability of these comments to the present study. The appendix B presents the fault tree models printed for each of the systems included and analyzed in the Internal Event Analysis for LVNPP. The appendice C presents the outputs of the TEMAC code, used for the cuantification of the dominant accident sequences as well as for the final core damage evaluation. (Author)

  15. Seismic qualification tests of fans of the NPP of Laguna Verde U-1 and U-2; Pruebas de calificacion sismica de ventiladores de la Central Laguna Verde U1 and U2

    Energy Technology Data Exchange (ETDEWEB)

    Jarvio C, G.; Garcia H, E. E.; Arguelles F, R.; Vela H, A. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Naranjo U, J. L., E-mail: gilberto.jarvio@inin.gob.mx [Comision Federal de Electricidad, Gerencia de Centrales Nucleoelectricas, Subgerencia de Ingenieria, Carretera Veracruz-Medellin Km 7.5, Dos Bocas, Veracruz (Mexico)

    2013-10-15

    This work presents the results of the seismic qualification tests applied to the fans that will be installed in the control panels of the three divisions of the diesel generators of the nuclear power plant (NPP) of Laguna Verde, Unit-1 and Unit-2. This seismic qualification process of the fans was carried out using two specimens that were tested in the seismic table (vibrating) of the Engineering Institute of Universidad Nacional Autonoma de Mexico (UNAM), in accordance with the requirements of the standard IEEE 344-1975, to satisfy the established requirements of seismic qualification in the technical specifications and normative documents required by the nuclear standards, in order to demonstrate its application in the diesel generators Divisions I, II and III of the NPP. The seismic qualification tests were developed on specimens that were retired of the NPP of Laguna Verde recently with a service life of 7.75 years. (Author)

  16. Analysis of internal events for the Unit 1 of the Laguna Verde Nuclear Power Station. Appendixes; Analisis de eventos internos para la Unidad 1 de la Central Nucleoelectrica de Laguna Verde. Apendices

    Energy Technology Data Exchange (ETDEWEB)

    Huerta B, A.; Lopez M, R. [Comision Nacional de Seguridad Nuclear y Salvaguardias, 03000 Mexico D.F. (Mexico)

    1995-07-01

    This volume contains the appendices for the accident sequences analysis for those internally initiated events for Laguna Verde Unit 1, Nuclear Power Plant. The appendix A presents the comments raised by the Sandia National Laboratories technical staff as a result of the review of the Internal Event Analysis for Laguna Verde Unit 1 Nuclear Power Plant. This review was performed during a joint Sandia/CNSNS multi-day meeting by the end 1992. Also included is a brief evaluation on the applicability of these comments to the present study. The appendix B presents the fault tree models printed for each of the systems included and.analyzed in the Internal Event Analysis for LVNPP. The appendice C presents the outputs of the TEMAC code, used for the cuantification of the dominant accident sequences as well as for the final core damage evaluation. (Author)

  17. Optimization of reloading Laguna Verde Central U1/U2, Federal Electricity Commission; Optimizacion de recargas Central Laguna Verde U1/U2, Comision Federal de Electricidad

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa G, J.M. [Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km. 45.5, Municipio de Alto Lucero, Veracruz (Mexico)

    2006-07-01

    The Laguna Verde Central from the beginning of the commercial operation settled down as maximum priority 'the total safety in its operation' taking in consideration the so much experience of the good operation and of multiple recharges made in a sure and reliable way, and without separate us of the safety mystic of the CLV, but looking for to be better every day a new challenge it settled down 'to compare us with the best plants in the world' and certainly to work to classify us like one of them. For this we established a 4.0 year old plan (2003/2006) for the effectiveness all the processes in the power station that allowed us to measure our acting with the same parameters that settle down at international level (nuclear safety, industrial safety, radiological safety, capacity factor, readiness factor, cleaning of the power station, attachment to procedures, attention to the detail and certainly to be competitive in the economic aspect, summing up means to be good in all the aspects). All the above mentioned would allow us to qualify us as level 1 of WANO (world proprietors association of nuclear centrals) at the end of the year 2006 and to pass to be part of this select group. After analyzing the acting record of the power station, evaluating our technical and economic capacity, the location of the installation besides revising the international experiences was defined that one of the concepts that impact considerably so much to the capacity factors and availability besides the dose and production cost is the duration of the recharge periods, for this reason the present work is elaborated. (Author)

  18. Planning of activities in the Laguna Verde Central planning at 12 weeks; Planeacion de Actividades en la Central Laguna Verde planeacion a doce semanas

    Energy Technology Data Exchange (ETDEWEB)

    Chimalpopoca, C. [Comision Federal de Electricidad, Central Laguna Verde, Subgerencia General de Operacion y Planeacion, Veracruz (Mexico)]. e-mail: carlos.chimalpopoca@cfe.gob.mx

    2007-07-01

    The universe of works that are carried out in a nuclear facility to maintain effective the structures, systems and components require of a continuous analysis, in the order of the maintenance frequencies that can be of the preventive, predictive or corrective type. Each component is associated to reserve parts, readiness of systems, in fulfillment to the operation technical specifications, to the environment of the one work; each component requires of a planning level, where it is distinguished with clarity when they are executed, in the operation stage, stop or recharge. This work has as end to show like the activities are planned during the operation, using planning methods to twelve weeks, where the reach of the task is conceptualized, operative requirements, of reserve parts, of the work environment analysis, of those radiological conditions, of the authorizations for their execution, the same execution and the evaluation post work like a technique to maintain in continuous improvement the tasks of the maintenance of the Units of the Power station. A motor valve to be worked in its internals requires access to the work point, it requires bill of the system, electric disconnection, maneuvers to disassemble actuators and retirement of thermal isolation if it applies, reserve parts of the caps joints, control mechanisms, personal, tools, radiological control. The success of the continuous operation of a power station is in the planning quality, the attention of each one of the details to assure that the components, structures and components stay effective to make their function when they are demanded. The planning task requires of experience and knowledge of each some of the components, the task of planning of activities and its execution is multidisciplinary This work has that purpose, to show the planning tools in the Laguna Verde Nuclear Power station, under the concept of twelve weeks. (Author)

  19. Electrical systems at the nuclear power plant of Laguna Verde after the event in Fukushima; Sistemas electricos en la central nucleoelectrica Laguna Verde despues del evento de Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Lopez J, J. F., E-mail: jflopez@cnsns.gob.mx [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Jose M. Barragan 779, Col. Narvarte, 03020 Ciudad de Mexico (Mexico)

    2016-09-15

    During the event at the nuclear power plant of Fukushima Daichii (Japan), the electrical systems were affected both Onsite and Offsite, which were lost for a long time with irreversible consequences. Therefore, the Mexican Regulatory Body known as the Comision Nacional de Seguridad Nuclear y Salvaguardias (CNSNS) has taken various actions to review the current capacity of the electrical systems at the nuclear power plant of Laguna Verde (NPP-LV) before an event beyond the design bases. The CNSNS made special inspections to the NPP-LV to verify the current capacity of the electrical systems of Ac and Dc; as a result of the inspections, requirements were generated that must be met to demonstrate that has the capacity to deal with events beyond the design bases. In addition, CNSNS has participated in the Ibero-American Forum to deal with resistance testing. Is important to note that prior to the event at the nuclear power plant of Fukushima, the NPP-LV had implemented 1) the project Extended Power Increase in both Units of the NPP-LV, and 2) the Generic Charter 2006-02, both issues are considered contributions in the robustness of electrical systems. But it is also important to mention that the US Nuclear Regulatory Commission will soon issue mitigation strategies for a Station Blackout event, which could involve new actions at nuclear power plants. Based on the aforementioned, the CNSNS concludes that all the actions being taken contribute to the strengthening of the NPP-LV electrical systems, in order to increase their reliability, safety and operation when these are required to deal with events beyond the design bases as the event occurred in Fukushima Daichii and avoid as far as possible, damage in the reactor cores of the NPP-LV. (Author)

  20. Actinides inventory of the nuclear power plant of Laguna Verde Unit 1; Inventario de actinidos de la Central Nuclear Laguna Verde Unidad 1

    Energy Technology Data Exchange (ETDEWEB)

    Martinez C, E.; Ramirez S, J. R. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Alonso V, G., E-mail: eduardo.martinez@inin.gob.mx [IPN, Escuela Superior de Fisica y Matematicas, Av. Instituto Politecnico Nacional s/n, U. P. Adolfo Lopez Mateos, Col. San Pedro Zacatenco, 07738 Mexico D. F. (Mexico)

    2013-10-15

    At the present time 435 nuclear power reactors exist for the electricity generation operating in the world and 63 in construction. Mexico has two reactors type BWR in the nuclear power plant of Laguna Verde. The nuclear fuel that is used in the nuclear reactors is retired of the reactor core when the energy that this contained has been extracted. This used fuel is known as spent nuclear fuel, the problem with this fuel is that was irradiated inside the reactor and continuous emitting a high radiation, as well as a significant heat quantity when being extracted, for what is necessary to maintain it in cooling and with some shielding to be protected of the radiation that emits. This objective is achieved confining the fuel in the spent nuclear fuel pool, where it is cooled and the same pool provides the necessary shielding to maintain the surroundings in safety radiation levels for the personnel that work in the power plant. An inconvenience of the pools is its limited storage capacity and that after certain time is necessary to remove the fuel, according to the established regulation to continue operating. To correct this inconvenience, two alternatives of spent fuel disposition exist, 1) the final disposition in deep geologic repositories and 2) the reprocessing and recycled of spent fuel. Each alternative presents its particularities and specific problems; however taking many years to be able to implement anyone of them. To carry out the second option, is indispensable to estimate the total mass of actinides generated in the spent nuclear fuel, that which represents to develop a methodology for it, this action is the main purpose of the present work. Inside our calculation method was necessary to appeal to diverse computation tools as the codes Origin-S and Keno V.a. Later on the obtained were compared with a problem type Benchmark, being obtained a smaller absolute error to 1.0%. (Author)

  1. Internal event analysis of Laguna Verde Unit 1 Nuclear Power Plant. System Analysis; Analisis de Eventos Internos para la Unidad 1 de la Central Nucleoelectrica de Laguna Verde. Analisis de sistemas

    Energy Technology Data Exchange (ETDEWEB)

    Huerta B, A.; Aguilar T, O.; Nunez C, A.; Lopez M, R. [Comision Nacional de Seguridad Nuclear y Salvaguardias, 03000 Mexico D.F. (Mexico)

    1993-07-01

    The Level 1 results of Laguna Verde Nuclear Power Plant PRA are presented in the {sup I}nternal Event Analysis of Laguna Verde Unit 1 Nuclear Power Plant{sup ,} CNSNS-TR-004, in five volumes. The reports are organized as follows: CNSNS-TR-004 Volume 1: Introduction and Methodology. CNSNS-TR-004 Volume 2: Initiating Event and Accident Sequences. CNSNS-TR-004 Volume 3: System Analysis. CNSNS-TR-004 Volume 4: Accident Sequence Quantification and Results. CNSNS-TR-004 Volume 5: Appendices A, B and C. This volume presents the results of the system analysis for the Laguna Verde Unit 1 Nuclear Power Plant. The system analysis involved the development of logical models for all the systems included in the accident sequence event tree headings, and for all the support systems required to operate the front line systems. For the Internal Event analysis for Laguna Verde, 16 front line systems and 5 support systems were included. Detailed fault trees were developed for most of the important systems. Simplified fault trees focusing on major faults were constructed for those systems that can be adequately represent,ed using this kind of modeling. For those systems where fault tree models were not constructed, actual data were used to represent the dominant failures of the systems. The main failures included in the fault trees are hardware failures, test and maintenance unavailabilities, common cause failures, and human errors. The SETS and TEMAC codes were used to perform the qualitative and quantitative fault tree analyses. (Author)

  2. Abundancia de juveniles de camarones peneidos comerciales en la zona norte de Laguna Madre, México Abundance of the commercial penaeid shrimp juveniles in the North zone of Laguna Madre, Mexico

    Directory of Open Access Journals (Sweden)

    Armando T. Wakida-Kusunoki

    2008-03-01

    Full Text Available Se tomaron muestras mensuales de agosto del 2005 a noviembre del 2006, para analizar los cambios de abundancia de juveniles de camarones peneidos comerciales en la parte norte de Laguna Madre, Tamaulipas. En cada una de las nueve estaciones de muestreo se realizó un arrastre nocturno, utilizando una red tipo chinchorro, de tamaño de malla de 1.25 cm y seis metros de longitud de relinga inferior. Se observaron tres especies de peneidos comerciales y cada una de ellas tuvo sus valores más altos de abundancia en diferentes periodos del año. El camarón café, Farfantepenaeus aztecus fue más abundante de abril-mayo; el camarón rosado, Farfantepenaeus dourarum en diciembre-enero y el camarón blanco, Litopenaeus setiferus en julio y septiembre. Estos resultados muestran que estas especies tienen un uso temporal diferencial en Laguna Madre, Tamaulipas.Monthly samplings were carried out during August, 2005 to November, 2006 to analizing the changes of the abundance of commercial juvenile penaeid shrimps in the North part of Laguna Madre, Tamaulipas. In every nine points a night trawl were carried out using a seine net of mesh size of 1.25 cm and 6 m length of bottom rope. Three commercial penaeid shrimp species were found and each one presented high abundance values for different periods of the year. Brown shrimp, Farfantepenaeus aztecus, in April-May period; pink shrimp, Farfantepenaeus dourarum, in December-January, and the white shrimp, Litopenaeus setiferus in July and September. These results showed that different species presented a differential temporal use in Laguna Madre.

  3. Humberto Hernández (2002, Una palabra ganada. Notas lingMsticas. La Laguna, Tenerife: Altasur Ediciones; 337 pp.

    Directory of Open Access Journals (Sweden)

    Jasmina Markič

    2003-12-01

    Full Text Available Humberto Hernández, filólogo español y catedrático de la Universidad de La Laguna es el autor de Una palabra ganada - Notas lingüísticas, libra publicado en el año 2002 por Altasur Ediciones de La Laguna, Tenerife, en la colección Ensayo. El título del libro Una palabra ganada es un verso de Rilke y refleja bien el objetivo de la obra: el interés por los problemas normativos de la lengua. Con palabras de Manuel Seco, autor del prólogo, “nada lees ajeno a Humberto Hernández. Siempre tiene algo que decir de este milagro del lenguaje, aunque sea para mostrar los tristes harapos que con él nos hacemos los hablantes«.

  4. Estudio preliminar de contaminación bacteriológica en la laguna Pueblo Viejo, Veracruz, México

    OpenAIRE

    Guadalupe Barrera Escorcia; Irma Wong Chang; Alma S Sobrino Figueroa; Xóchitl Guzmán García; Fabiola Hernández Galindo; Fernando Saavedra Villeda

    1998-01-01

    La contaminación bacteriológica de la laguna de Pueblo Viejo fue evaluada en agua, sedimento y ostión, a través de las concentraciones de bacterias coliformes y estreptococos fecales (en dos épocas del año). Los conteos se realizaron utilizando la técnica de tubos múltiples de fermentación y se determinaron parámetros fisicoquímicos simultáneamente. Los resultados indican que el agua de la laguna fue inadecuada tanto para el cultivo de ostión, como para la recreación con contacto primario y p...

  5. La pantalla de papel. El cine en la prensa de La Laguna antes de la guerra civil

    Directory of Open Access Journals (Sweden)

    Lic. Enrique Ramírez Guedes

    1998-01-01

    Full Text Available Con la llegada del cine a la ciudad de La Laguna (Tenerife, Islas Canarias, en 1906, la prensa local comienza a tomar conciencia de la importancia del nuevo medio y a realizar un minucioso seguimiento de su devenir. Ya desde los primeros momentos las páginas de los rotativos laguneros sirven como plataforma para la difusión de las ideas y opiniones que en materia cinematográfica se estaban gestando entre los intelectuales locales, provocando verdaderos debates sobre su utilidad, sus repercusiones éticas y morales, o, más relacionado con lo cinematográfico, su calidad estética. Este notable interés por el cine se mantiene como una constante hasta el estallido de la guerra civil española, época en que se extingue el último periódico de La Laguna.

  6. Cloacal flora isolated from wild black-bellied whistling ducks (Dendrocygna autumnalis) in Laguna La Nacha, Mexico.

    Science.gov (United States)

    Aguirre, A A; Quan, T J; Cook, R S; McLean, R G

    1992-01-01

    Cloacal swabs from 110 adult black-bellied whistling ducks trapped at Laguna La Nacha, Tamaulipas, Mexico, were cultured to determine the prevalence of normal and potentially pathogenic bacteria. Twenty-five gram-negative enterobacteria and four gram-positive cocci were isolated. The most common isolates included Escherichia coli (54%), Staphylococcus spp. (29%), Streptococcus spp. (22%), Aeromonas hydrophila (15%) Enterobacter cloacae (14%), and Micrococcus sp. (14%). The implications of whistling ducks as possible reservoirs of pathogenic bacteria are discussed.

  7. A 6000-year record of ecological and hydrological changes from Laguna de la Leche, north coastal Cuba

    Science.gov (United States)

    Peros, Matthew C.; Reinhardt, Eduard G.; Davis, Anthony M.

    2007-01-01

    Laguna de la Leche, north coastal Cuba, is a shallow (≤ 3 m), oligohaline (˜ 2.0-4.5‰) coastal lake surrounded by mangroves and cattail stands. A 227-cm core was studied using loss-on-ignition, pollen, calcareous microfossils, and plant macrofossils. From ˜6200 to ˜ 4800 cal yr BP, the area was an oligohaline lake. The period from ˜ 4800 to ˜ 4200 cal yr BP saw higher water levels and a freshened system; these changes are indicated by an increase in the regional pollen rain, as well as by the presence of charophyte oogonia and an increase in freshwater gastropods (Hydrobiidae). By ˜ 4000 cal yr BP, an open mesohaline lagoon had formed; an increase in salt-tolerant foraminifers suggests that water level increase was driven by relative sea level rise. The initiation of Laguna de la Leche correlates with a shift to wetter conditions as indicated in pollen records from the southeastern United States (e.g., Lake Tulane). This synchronicity suggests that sea level rise caused middle Holocene environmental change region-wide. Two other cores sampled from mangrove swamps in the vicinity of Laguna de la Leche indicate that a major expansion of mangroves was underway by ˜ 1700 cal yr BP.

  8. Uranium mobility and accumulation along the Rio Paguate, Jackpile Mine in Laguna Pueblo, NM.

    Science.gov (United States)

    Blake, Johanna M; De Vore, Cherie L; Avasarala, Sumant; Ali, Abdul-Mehdi; Roldan, Claudia; Bowers, Fenton; Spilde, Michael N; Artyushkova, Kateryna; Kirk, Matthew F; Peterson, Eric; Rodriguez-Freire, Lucia; Cerrato, José M

    2017-04-19

    The mobility and accumulation of uranium (U) along the Rio Paguate, adjacent to the Jackpile Mine, in Laguna Pueblo, New Mexico was investigated using aqueous chemistry, electron microprobe, X-ray diffraction and spectroscopy analyses. Given that it is not common to identify elevated concentrations of U in surface water sources, the Rio Paguate is a unique site that concerns the Laguna Pueblo community. This study aims to better understand the solid chemistry of abandoned mine waste sediments from the Jackpile Mine and identify key hydrogeological and geochemical processes that affect the fate of U along the Rio Paguate. Solid analyses using X-ray fluorescence determined that sediments located in the Jackpile Mine contain ranges of 320 to 9200 mg kg(-1) U. The presence of coffinite, a U(iv)-bearing mineral, was identified by X-ray diffraction analyses in abandoned mine waste solids exposed to several decades of weathering and oxidation. The dissolution of these U-bearing minerals from abandoned mine wastes could contribute to U mobility during rain events. The U concentration in surface waters sampled closest to mine wastes are highest during the southwestern monsoon season. Samples collected from September 2014 to August 2016 showed higher U concentrations in surface water adjacent to the Jackpile Mine (35.3 to 772 μg L(-1)) compared with those at a wetland 4.5 kilometers downstream of the mine (5.77 to 110 μg L(-1)). Sediments co-located in the stream bed and bank along the reach between the mine and wetland had low U concentrations (range 1-5 mg kg(-1)) compared to concentrations in wetland sediments with higher organic matter (14-15%) and U concentrations (2-21 mg kg(-1)). Approximately 10% of the total U in wetland sediments was amenable to complexation with 1 mM sodium bicarbonate in batch experiments; a decrease of U concentration in solution was observed over time in these experiments likely due to re-association with sediments in the reactor. The

  9. The Maars of the Tuxtla Volcanic Field: the Example of 'laguna Pizatal'

    Science.gov (United States)

    Espindola, J.; Zamora-Camacho, A.; Hernandez-Cardona, A.; Alvarez del Castillo, E.; Godinez, M.

    2013-12-01

    Los Tuxtlas Volcanic Field (TVF), also known as Los Tuxtlas massif, is a structure of volcanic rocks rising conspicuously in the south-central part of the coastal plains of eastern Mexico. The TVF seems related to the upper cretaceous magmatism of the NW part of the Gulf's margin (e.g. San Carlos and Sierra de Tamaulipas alkaline complexes) rather than to the nearby Mexican Volcanic Belt. The volcanism in this field began in late Miocene and has continued in historical times, The TVF is composed of 4 large volcanoes (San Martin Tuxtla, San Martin Pajapan, Santa Marta, Cerro El Vigia), at least 365 volcanic cones and 43 maars. In this poster we present the distribution of the maars, their size and depths. These maars span from a few hundred km to almost 1 km in average diameter, and a few meters to several tens of meters in depth; most of them filled with lakes. As an example on the nature of these structures we present our results of the ongoing study of 'Laguna Pizatal or Pisatal' (18° 33'N, 95° 16.4'W, 428 masl) located some 3 km from the village of Reforma, on the western side of San Martin Tuxtla volcano. Laguna Pisatal is a maar some 500 meters in radius and a depth about 40 meters from the surrounding ground level. It is covered by a lake 200 m2 in extent fed by a spring discharging on its western side. We examined a succession of 15 layers on the margins of the maar, these layers are blast deposits of different sizes interbedded by surge deposits. Most of the contacts between layers are irregular; which suggests scouring during deposition of the upper beds. This in turn suggests that the layers were deposited in a rapid series of explosions, which mixed juvenile material with fragments of the preexisting bedrock. We were unable to find the extent of these deposits since the surrounding areas are nowadays sugar cane plantations and the lake has overspilled in several occassions.

  10. Multivariate analysis in the frequency mastery applied to the Laguna Verde Central; Analisis multivariable en el dominio de la frecuencia aplicado a la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Castillo D, R.; Ortiz V, J. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Calleros M, G. [CFE, Central Nucleoelectrica de Laguna Verde, carretera Nautla-Cardel Km. 42.5, Alto Lucero, Veracruz (Mexico)]. e-mail: rcd@nuclear.inin.mx

    2006-07-01

    The noise analysis is an auxiliary tool in the detection of abnormal operation conditions of equipment, instruments or systems that affect to the dynamic behavior of the reactor. The spectral density of normalized power has usually been used (NPSD, by its initials in English), to watch over the behavior of some components of the reactor, for example, the jet pumps, the recirculation pumps, valves of flow control in the recirculation knots, etc. The behavior change is determined by individual analysis of the NPSD of the signals of the components in study. An alternative analysis that can allow to obtain major information on the component under surveillance is the multivariate autoregressive analysis (MAR, by its initials in English), which allows to know the relationship that exists among diverse signals of the reactor systems, in the time domain. In the space of the frequency, the relative contribution of power (RPC for their initials in English) it quantifies the influence of the variables of the systems on a variable of interest. The RPC allows, therefore that for a peak shown in the NPSD of a variable, it can be determine the influence from other variables to that frequency of interest. This facilitates, in principle, the pursuit of the important physical parameters during an event, and to study their interrelation. In this work, by way of example of the application of the RPC, two events happened in the Laguna Verde Central are analyzed: the rods blockade alarms by high scale in the monitors of average power, in which it was presents a power peak of 12% of width peak to peak, and the power oscillations event. The main obtained result of the analysis of the control rods blockade alarm event was that it was detected that the power peak observed in the signals of the average power monitors was caused by the movement of the valve of flow control of recirculation of the knot B. In the other oscillation event the results its show the mechanism of the oscillation of

  11. Genetic structure of populations of Drosophila melanogaster natives from Laguna Verde, Veracruz; Estructura genetica de poblaciones de Drosophila melanogaster originarias de Laguna Verde, Veracruz

    Energy Technology Data Exchange (ETDEWEB)

    Salceda, V.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: vmss@nuclear.inin.mx

    2005-07-01

    The genetic variability hidden present in natural populations of Drosophila melanogaster, it has been broadly analyzed, and it is a tool that allows to detect differences among the different populations of this species, so much of natural nature as experimental. In this occasion we use it to see if differences exist in two neighboring populations inside the Laguna Verde nuclear power plant, Veracruz, and this way to suggest, of having differences in the mount of the relative frequencies of lethal genes, semi lethals and normal, be due to the radioactive emanations product of the reactors operation of the plant. Its were took samples of flies in both towns during three successive seasons and they were transported to the laboratory of the ININ where they were carried out the tests to determine the frequency of the different types of genes. This was made by means of the denominated technique C y L / Pm that allows by means of a cross series with a stump marker to obtain, in the third generation, in isolated form the different types of genes and this way to calculate their relative frequencies. The study understands the analysis of 299 chromosomes extracted from the populations, of those that 95 correspond at the control population and 204 to the experimental one. As a result of the analysis we find that 30.52 percent of the genes of the population witness contains detrimental genes (sum of the lethal plus the semi lethal genes) as long as in the experimental population this value corresponds to 23.03 percent. In accordance with this information was not significant difference among the studied populations. A similar analysis, but now comparing the seasons, (summer against winter), it showed significant difference to 5% with regard to the lethal genes frequency only in the population witness. These results indicate the absence of damage, however it is necessary to consider that this can be due to that indeed there is not him or that the investigation protocol is not

  12. Generation of the ECP database (ECP02.DAT) at the beginning of the cycle 1 of the Unit 1 of Laguna Verde; Generacion de la base ECP (ECP02.DAT) al inicio del ciclo 1 de la Unidad 1 de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Perusquia C, R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1992-10-15

    In order to carrying out a comparison among the results provided for the Program of Estimate of the ECP Critical Position and the Shutdown/Startup produced in the Cycle 1 of the Unit 1 of Laguna Verde, it was generated the base of the ECP program, following the outlines settled down in the Procedure 'Generation of ECP Database for Laguna Verde' (IT.SN/DFR 074). Next the data sheets filled when being generated the ECP02.DAT database at the beginning of the cycle are provided. In the IT.SN/DFR 079 report 'Adjustment and Preliminary Evaluation of the Predictions of Criticity of the ECP Program with Reported Data of Cycle 1 of the Unit 1 of Laguna Verde, the results of the comparison among the estimates of the ECP program using the ECP02.DAT with the real data of the Cycle 1 of the Unit 1 of Laguna Verde are presented. (Author)

  13. Waterbirds and human-related threats to their conservation in Laguna Cuyutlán, Colima, México

    Directory of Open Access Journals (Sweden)

    Eric Mellink

    2009-06-01

    Full Text Available Laguna Cuyutlán, the only large wetland in a span of 1 150 km along the Pacific coast of México, has been neglected as to its importance for waterbird conservation. At least 25 waterbird species nest there, with some of their colonies being very relevant, and at least 61 waterbird species use the lagoon during their nonbreeding season. This lagoon has been subject to several structural modifications, including levees and artificial channels which connect it to the sea, while water supply from continental sources has diminished, although its role has not been assessed yet. Salt extraction and artisanal fishery, the main economic activities, do not seem to pose a threat to waterbirds. Among potential threats to this acquatic ecosystem, are the raw sewage discharges that exist near urban areas, and pesticides from the surrounding agricultural lands might reach the lagoon. Seemingly, the most serious threat comes from waterway development in connection with a re-gasification plant to be built, and planned future port expansion, which could potentially increase water levels and alter important habitats for nesting and foraging. We recommend that: the area be declared an Important Bird Area; the development of the re-gasification plant and future port includes a levee to prevent alterations in water level in the remaining sections of the lagoon; supply of exogenous chemicals and waste products be prevented and monitored; alleged benefits from water interchange between the lagoon and the sea through artificial channels should be re-evaluated; and the role of fresh water supplies to the lagoon should be paid attention to. Rev. Biol. Trop. 57 (1-2: 1-12. Epub 2009 June 30.Laguna Cuyutlán, el único humedal grande a lo largo de 1 150 km del Pacífico mexicano, no ha sido considerado un ecosistema natural importante para la conservación de aves acuáticas. Cuando menos 25 especies de aves acuáticas anidan ahí, y al menos 61 especies de aves acu

  14. Estimating floodplain sedimentation in the Laguna de Santa Rosa, Sonoma County, CA

    Science.gov (United States)

    Curtis, Jennifer A.; Flint, Lorraine E.; Hupp, Cliff R.

    2013-01-01

    We present a conceptual and analytical framework for predicting the spatial distribution of floodplain sedimentation for the Laguna de Santa Rosa, Sonoma County, CA. We assess the role of the floodplain as a sink for fine-grained sediment and investigate concerns regarding the potential loss of flood storage capacity due to historic sedimentation. We characterized the spatial distribution of sedimentation during a post-flood survey and developed a spatially distributed sediment deposition potential map that highlights zones of floodplain sedimentation. The sediment deposition potential map, built using raster files that describe the spatial distribution of relevant hydrologic and landscape variables, was calibrated using 2 years of measured overbank sedimentation data and verified using longer-term rates determined using dendrochronology. The calibrated floodplain deposition potential relation was used to estimate an average annual floodplain sedimentation rate (3.6 mm/year) for the ~11 km2 floodplain. This study documents the development of a conceptual model of overbank sedimentation, describes a methodology to estimate the potential for various parts of a floodplain complex to accumulate sediment over time, and provides estimates of short and long-term overbank sedimentation rates that can be used for ecosystem management and prioritization of restoration activities.

  15. Transformation to Eco-Agri Tourism: The Case of Casile, Cabuyao City, Laguna, Philippines

    Directory of Open Access Journals (Sweden)

    Tuzon Troy P.

    2014-01-01

    Full Text Available The study was conducted to determine the acceptability of the residents of Barangay Casile, Cabuyao, Laguna, Philippines in transforming their locality into an eco-agri tourism site. A total of 241 residents participated in the data collection using a survey questionnaire and interviews. Barangay Casile is an agricultural area and is also noted for its natural heritage such as the Matang Tubig River and Falls and the Marcos Twin Tower. Because of this, the local government unit of Cabuyao City plans to develop the area as a nature- based tourism destination specifically as an eco-agri tourism site. The survey revealed that the respondents agreed on the proposition of transforming their area into agri-tourism site. Cultural acceptability ranks the highest which means that the locals are open on the possible effects on their culture that the development could bring them. Economic and social acceptability were also ranked high because of the income they could get from the influx of tourists. Environmental acceptability is the least agreeable because most of the respondents were environment sensitive and are concerned with the changes to the natural façade of their area. It can be concluded that agri-tourism development involving local residents provides control over the development and management of the project.

  16. Evaluación de aves en la laguna El Paraiso, Lima, Perú

    Directory of Open Access Journals (Sweden)

    Zoila Cruz

    2013-04-01

    Full Text Available Este estudio se realizó en la laguna El Paraíso, departamento de Lima, Perú, de abril de 1999 a abril del 2000. Tuvo como objetivos la determinación de la diversidad específi ca en aves; la densidad poblacional de las principales familias de uso cinegético y la determinación de los microhábitats más importantes para los grupos evaluados. Se reportaron 81 especies de aves las cuales pertenecen a 62 géneros y a 35 familias. En esta cifra se reportan 19 especies nuevas para el área de Paraíso; el 46% de la diversidad de aves está dada por las familias Scolopacidae (14%, Ardeidae (10%, Laridae (7%, Anatidae (5%, Charadriidae (5% y Columbidae (5%. La familia Rallidae es la más abundante y está representada por dos especies Gallinula chloropus “polla de agua” y Fulica ardesiaca“gallareta”, siendo la primera más numerosa. Asimismo, se dan las recomendaciones para la conservación del área.

  17. Laguna Negra Virus Infection Causes Hantavirus Pulmonary Syndrome in Turkish Hamsters (Mesocricetus brandti).

    Science.gov (United States)

    Hardcastle, K; Scott, D; Safronetz, D; Brining, D L; Ebihara, H; Feldmann, H; LaCasse, R A

    2016-01-01

    Laguna Negra virus (LNV) is a New World hantavirus associated with severe and often fatal cardiopulmonary disease in humans, known as hantavirus pulmonary syndrome (HPS). Five hamster species were evaluated for clinical and serologic responses following inoculation with 4 hantaviruses. Of the 5 hamster species, only Turkish hamsters infected with LNV demonstrated signs consistent with HPS and a fatality rate of 43%. Clinical manifestations in infected animals that succumbed to disease included severe and rapid onset of dyspnea, weight loss, leukopenia, and reduced thrombocyte numbers as compared to uninfected controls. Histopathologic examination revealed lung lesions that resemble the hallmarks of HPS in humans, including interstitial pneumonia and pulmonary edema, as well as generalized infection of endothelial cells and macrophages in major organ tissues. Histologic lesions corresponded to the presence of viral antigen in affected tissues. To date, there have been no small animal models available to study LNV infection and pathogenesis. The Turkish hamster model of LNV infection may be important in the study of LNV-induced HPS pathogenesis and development of disease treatment and prevention strategies.

  18. Radiocarbon dating of the Peruvian Chachapoya/Inca site at the Laguna de los Condores

    Energy Technology Data Exchange (ETDEWEB)

    Wild, Eva Maria [Vienna Environmental Research Accelerator (VERA) Laboratory, Fakultaet fuer Physik, Universitaet Wien, Waehringer Str. 17, A-1090 Vienna (Austria)]. E-mail: eva.maria.wild@univie.ac.at; Guillen, Sonia [Centro Mallqui, The Bioanthropology Foundation Peru, Ilo (Peru); Kutschera, Walter [Vienna Environmental Research Accelerator (VERA) Laboratory, Fakultaet fuer Physik, Universitaet Wien, Waehringer Str. 17, A-1090 Vienna (Austria); Seidler, Horst [Department fuer Anthropologie, Universitaet Wien, Althanstrasse 14, A-1090 Vienna (Austria); Steier, Peter [Vienna Environmental Research Accelerator (VERA) Laboratory, Fakultaet fuer Physik, Universitaet Wien, Waehringer Str. 17, A-1090 Vienna (Austria)

    2007-06-15

    In 1997 a new archaeological site was discovered in the Peruvian tropical rain forest. The site is located in an area which has been occupied by the Chachapoya, a pre-Incan people, from about 800AD on. The site comprises a large funerary place with several mausoleums built in the cliffs next to the Laguna de los Condores. More than 200 human mummies and funerary bone-bundles together with numerous grave artefacts have been found there. Although the site has been ascribed to the Chachapoya, the mummification method used is very similar to the one applied by the Inca. As part of an ongoing multidisciplinary project to explore the history of this site and of the Chachapoya people, twenty-seven (27) {sup 14}C-AMS age determinations were performed. Samples, bones and textile wrappings as well as samples from a funerary bone bundle plus associated grave artefacts were dated. The {sup 14}C data show that the site originates from the Chachapoya pre-Inca period and that in addition, it was used as a funerary place during the subsequent Inca occupation era. The radiocarbon results indicate that the Chachapoya may have changed their burial tradition due to the colonization by the Inca.

  19. Stratigraphy and Characterization of Volcanic Deposits on the Northwestern Flanks of Mt. Makiling, Laguna, Philippines

    Science.gov (United States)

    Ybanez, R. L.; Bonus, A. A. B.; Judan, J. M.; Racoma, B. A.; Morante, K. A. M.; Balangue, M. I. R. D.

    2014-12-01

    Mt. Makiling is an inactive stratovolcano located in the province of Laguna. Semi-detailed geologic field mapping on the northwestern low-level flanks and apron of the volcano was conducted. Exposures reveal a volcanic terrain hosting a wide variety of volcanic rocks: lava flows, pyroclastic surges, pyroclastic flows, and tuff deposits. Stratigraphic logging of the volcanic deposits showed differences in occurrence of the deposit types as well as their characteristics. The pyroclastic flow deposits are found at the base of the column overlain by pyroclastic surges which were more common in the area. Capping the pyroclastic surges is a thin layer of tuffaceous units. Isolated deposits of lava flows of andesitic composition were mapped in the western flank of Mt. Makiling. These varying volcanic deposits are derived from different eruptive activities of Mt. Makiling, with at least three separate eruptive episodes indicated by the exposed deposits. Two separate explosive eruptions are marked by two different pyroclastic deposits, while an effusive episode, marked by andesitic lava flows, can also be identified. The pyroclastic surge deposit is uncharacteristically thick, around a hundred meters or more exposed, providing further questions as to the magnitude of past eruptions or the mechanism of pyroclastic material deposition around the volcano. Mt. Makiling, thus, has historically undergone different eruption types, but still releases generally the same material composition across varying deposits: intermediate or andesitic composition. This is consistent with the trend of Philippine volcanoes, and with the Macolod corridor which hosts this volcanic system.

  20. Las lagunas estratigráficas y las superficies negativas en arqueología

    Directory of Open Access Journals (Sweden)

    Murillo Fragero, José I.

    2004-12-01

    Full Text Available Owing much to geological research, archaeological stratigraphy and its tools and principles are developed through continuous experiences following a model of critical study and reflection. In this case, we have attempted to approach the issue of stratigraphic gaps, a concept that includes various processes (hiatuses, erosional gaps and that we have identified through negative surfaces. Their definition and documentation is often vital in archaeological analysis and historical archaeology.La estratigrafía arqueológica, deudora de la investigación geológica, templa sus herramientas y desarrolla sus principios gracias a las continuas experiencias llevadas a cabo de acuerdo a un modelo de trabajo y reflexión crítico. En este caso, hemos pretendido un acercamiento al tema de las lagunas estratigráficas, concepto que encierra distintos procesos (hiatos, vacíos erosionales y que identificamos gracias a las superficies negativas. Su definición y documentación es, a menudo, clave en el análisis arqueológico de la arquitectura histórica.

  1. Vegetation and climate history from Laguna de Río Seco, Sierra Nevada, southern Spain

    Science.gov (United States)

    Anderson, R. S.; Jimenez-Moreno, G.

    2010-12-01

    The largest mountain range in southern Spain - the Sierra Nevada - is an immense landscape with a rich biological and cultural heritage. Rising to 3,479 m at the summit of Mulhacén, the range was extensively glaciated during the late Pleistocene. Subsequent melting of cirque glaciers allowed formation of numerous small lakes and wetlands. One south-facing basin contains Laguna de Río Seco, a small lake at ca. 3020 m elevation, presently above potential treeline. Pollen analysis of sediment cores documents over 11,000 calendar years of vegetation change there. The early record, to ca. 5,700 cal yr BP, is dominated by pine pollen, with birch, deciduous oak, and grass, with an understory of shrubs types. Pine trees probably never grew at the elevation of the lake, but aquatic microfossils indicate lake levels were highest prior to ca. 7,800 cal yr BP, perhaps as a result of heavy winter precipitation, and early Holocene expansion of the ITCZ. Drier conditions commenced by 5,700 cal yr BP, shown by declines in wetland pollen, and increases in high elevation steppe shrubs more common today (juniper, sage, and others). The local and regional impact of humans increased substantially after ca. 2700 years ago, with the regional loss of pine forest or woodland, increases in pollen and spore types associated with pasturing, and olive cultivation at lower elevations.

  2. Estructura del ensamble de anuros de la Reserva Integral Laguna de los Padres (Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Stellatelli, Oscar Aníbal

    2010-11-01

    Full Text Available La Reserva Municipal Integral Laguna de los Padres (RILaPa contiene al humedal más grande del Partido de General Pueyrredón que conserva una fracción valiosa del patrimonio cultural y natural de los humedales pampeanos. Conocer no sólo el listado de las especies de anfibios presentes, sino también el "dónde, cuándo y cómo se localizan esas especies", es información que sirve como punto de partida para monitorear posteriormente su estado y evaluar las causas de posibles fluctuaciones numéricas. Por estas razones, el objetivo general de este trabajo es relevar la composición, abundancia relativa, distribución espacial y estado sanitario general de las poblaciones, haciendo un énfasis comparativo entre las áreas destinadas a la conservación y a la recreación.

  3. Strategic planning 2007-2011, an opportunity for quality, competitiveness and excellence of the Laguna Verde Central; Planeacion estrategica 2007-2011, una oportunidad para la calidad, competitividad y excelencia de la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Rivera C, A. [CFE, Central Laguna Verde, Kilometro 42.5 Cardel Nautla, Veracruz (Mexico)]. e-mail: arr99999@cfe.gob.mx

    2007-07-01

    The reason is to give to know to the nuclear community in Mexico the good results that it located in the 2006 to the Laguna Verde Nucleo electric Central in the classification of the World Association of Nuclear Operators (WANO) like one of the best in the worldwide scale, and their Strategic Plan 2007-2011 like an opportunity to continue improving the Quality, the Competitiveness and the Excellency in their Generating Units. It stands out that the fuel reloads are carried out in systemic form in less than 30 days, and also other achievements like it is the certificate granted by PROFEPA of Clean Industry, the renovation of the Certifications of the ISO-9001 and the ISO-14001, as well as the accredit of the Laboratories, and they will give data of the project of the increment of power that their power rose in 15%. For those results in the Strategic Planning 2007-2011 are pointed out that the Laguna Verde Central is a highly viable option in Mexico, when continuing with reloads that will allow a capacity factor up of 90%, and the other concepts that will give the obtaining of the qualification level 1 of WANO in this strategic period. Finally I will conclude with the good news for the Nuclear Industry in Mexico that published the Reforma newspaper at November 01, 2006: 'To the president of Mexico, Felipe Calderon, interests him to impel during his command the alternating energy sources to the hydrocarbons, known it is that the hydrocarbons (petroleum, coal or natural gas) they are finite, while the appetite of the world for the energy is infinite. As you they know, Mexico possesses a nuclear plant that generates energy starting from enriched uranium: the famous Laguna Verde Thermonuclear Central. He declared that Mexico can and it should advance for the one on the way to the energy generation for the nuclear road.' (Author)0.

  4. Internal event analysis for Laguna Verde Unit 1 Nuclear Power Plant. Accident sequence quantification and results; Analisis de eventos internos para la Unidad 1 de la Central Nucleoelectrica de Laguna Verde. Cuantificacion de secuencias de accidente y resultados

    Energy Technology Data Exchange (ETDEWEB)

    Huerta B, A.; Aguilar T, O.; Nunez C, A.; Lopez M, R. [Comision Nacional de Seguridad Nuclear y Salvaguardias, 03000 Mexico D.F. (Mexico)

    1994-07-01

    The Level 1 results of Laguna Verde Nuclear Power Plant PRA are presented in the {sup I}nternal Event Analysis for Laguna Verde Unit 1 Nuclear Power Plant, CNSNS-TR 004, in five volumes. The reports are organized as follows: CNSNS-TR 004 Volume 1: Introduction and Methodology. CNSNS-TR4 Volume 2: Initiating Event and Accident Sequences. CNSNS-TR 004 Volume 3: System Analysis. CNSNS-TR 004 Volume 4: Accident Sequence Quantification and Results. CNSNS-TR 005 Volume 5: Appendices A, B and C. This volume presents the development of the dependent failure analysis, the treatment of the support system dependencies, the identification of the shared-components dependencies, and the treatment of the common cause failure. It is also presented the identification of the main human actions considered along with the possible recovery actions included. The development of the data base and the assumptions and limitations in the data base are also described in this volume. The accident sequences quantification process and the resolution of the core vulnerable sequences are presented. In this volume, the source and treatment of uncertainties associated with failure rates, component unavailabilities, initiating event frequencies, and human error probabilities are also presented. Finally, the main results and conclusions for the Internal Event Analysis for Laguna Verde Nuclear Power Plant are presented. The total core damage frequency calculated is 9.03x 10-5 per year for internal events. The most dominant accident sequences found are the transients involving the loss of offsite power, the station blackout accidents, and the anticipated transients without SCRAM (ATWS). (Author)

  5. Introduction of fuel GE14 in the nuclear power plant of Laguna Verde for the extended increase of power; Introduccion del combustible GE14 en la central nuclear Laguna Verde para el aumento de potencia extendido

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, N.; Vargas A, A. F.; Cardenas J, J. B.; Contreras C, P. [CFE, Central Nuclear Laguna Verde, Subgerencia de Ingenieria, Carretera Veracruz-Medellin Km. 7.5 (Mexico)]. e-mail: natividad.hernandez@cfe.gob.mx

    2008-07-01

    The project of extended increase of power responds to a necessity of electrical energy in the country, increasing the thermal exit of the reactors of the nuclear power plant of Laguna Verde of 2027 MWt to 2317 MWt. In order to support this transition, changes will make in the configuration of the reactor core and in the operation strategies of the cycle, also they will take initiatives to optimize the economy in fuel cycle. At present in both reactors of the nuclear plant of Laguna Verde fuel GE12 is used. The fuel GE14 presents displays with respect to the GE12, some improvements in the mechanical design and consequently in its performance generally. Between these improvements we can mention: 1. Spacers of high performance. 2. Shielding with barrier. 3. Filter for sweepings {sup d}ebris{sup a}nd 4. Fuel rods of minor partial length. The management of nuclear power plants has decided to introduce the use of fuel GE14 in Laguna Verde in the reload 14 for Unit 1 and of the reload 10 for Unit 2. The process of new introduction fuel GE14 consists of two stages, first consists on subjecting the one new design of fuel to the regulator organism in the USA: Nuclear Regulatory Commission, in Mexico the design must be analyzed and authorized by the National Commission of Nuclear Safety and Safeguards, for its approval of generic form, by means of the demonstration of the fulfillment with the amendment 22 of GESTAR II, the second stage includes the specific analyses of plant to justify the use of the new fuel design in a reload core. The nuclear plant of Laguna Verde would use some of the results of the security analyses that have been realized for the project of extended increase of power with fuel GE14, to document the specific analyses of plant with the new fuel design. The result of the analyses indicates that the reload lots are increased of 116-120 assemblies in present conditions (2027 MWt) to 140-148 assemblies in conditions of extended increase of power (2317 MWt

  6. Abundancia de juveniles de camarones peneidos comerciales en la zona norte de Laguna Madre, México Abundance of the commercial penaeid shrimp juveniles in the North zone of Laguna Madre, Mexico

    OpenAIRE

    Armando T. Wakida-Kusunoki; Leobardo García-Solorio; Norma Gloria Vázquez Benavides

    2008-01-01

    Se tomaron muestras mensuales de agosto del 2005 a noviembre del 2006, para analizar los cambios de abundancia de juveniles de camarones peneidos comerciales en la parte norte de Laguna Madre, Tamaulipas. En cada una de las nueve estaciones de muestreo se realizó un arrastre nocturno, utilizando una red tipo chinchorro, de tamaño de malla de 1.25 cm y seis metros de longitud de relinga inferior. Se observaron tres especies de peneidos comerciales y cada una de ellas tuvo sus valores más altos...

  7. Transient simulations, empirical reconstructions and forcing mechanisms for the Mid-holocene hydrological climate in southern Patagonia

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Sebastian; Widmann, Martin; Jones, Julie [Institute for Coastal Research, GKSS Research Centre, Geesthacht (Germany); Haberzettl, Torsten; Ohlendorf, Christian; Zolitschka, Bernd [University of Bremen, Institute of Geography, Bremen (Germany); Luecke, Andreas; Mayr, Christoph [Research Centre Juelich, Institute of Chemistry and Dynamics of the Geosphere V, Juelich (Germany); Schaebitz, Frank [University of Cologne, Seminar for Geography and its Didactics, Cologne (Germany)

    2007-09-15

    This study investigates the atmospheric circulation in transient climate simulations with a coupled atmosphere-ocean general circulation model (GCM) for the mid-Holocene (MH) period 7-4.5 ka BP driven with combinations of orbital, solar and greenhouse gas forcings. The focus is on southern South America. Statistical downscaling models are derived from observational data and applied to the simulations to estimate precipitation in south-eastern Patagonia during the MH. These estimates are compared with lake level estimates for Laguna Potrok Aike (LPA) from sediments. Relative to pre-industrial conditions (i.e. 1550-1850), which show extraordinarily high lake levels, the proxy-based reconstructed lake levels during the MH are lower. The downscaled simulated circulation differences indicate higher LPA precipitation during the MH from March to August, higher annual means, and reduced precipitation from September to February. Thus the reconstructed lower LPA lake levels can not be explained solely by the simulated precipitation changes. Possible reasons for this discrepancy are discussed. Based on proxy data from southern South America hypotheses have also been proposed on the latitudinal position of the southern hemispheric westerlies (SHWs). In agreement with some of these hypotheses our simulations show an increased seasonal cycle of the latitudinal position of the SHWs during the MH, which can be explained by the orbital forcing. The simulations also show stronger SHWs over southern Patagonia during austral summer and weaker SHWs during winter. The downscaling model associates weaker SHWs with increased precipitation in the LPA region. However, this relationship is only moderate, and therefore the downscaling model does not support the assumption of a strong link between mean SHWs and precipitation over south-eastern Patagonia, which is the basis of many proxy-based hypotheses about the SHWs. (orig.)

  8. Nutrientes y productividad primaria fitoplanctónica en una laguna costera tropical intermitente (La Mancha,Ver.) del Golfo de México

    OpenAIRE

    Francisco Contreras Espinosa; Nadia E. Rivera Guzmán; Raquel Segura Aguilar

    2005-01-01

    En el caso de la laguna de La Mancha, el efecto de la apertura de la boca implica que la laguna pierda, a lo largo de este período (157 días) 1’148,400 m3 de su volumen original; cuando la boca se cierra, el incremento de agua hacia el interior del sistema se calcula en aproximadamente 950,400 m3 alcanzando 1’ 663,200 m3. Cuando la laguna permaneció comunicada con el mar (del 23 de junio al 25 de noviembre), los parámetros medidos mostraron las siguientes medianas: la salinidad de 22.0 ups, e...

  9. Field reconnaissance of the effects of the earthquake of April 13, 1973, near Laguna de Arenal, Costa Rica

    Science.gov (United States)

    Plafker, George

    1973-01-01

    At about 3:34 a.m. on April 13, 1973, a moderate-sized, but widely-felt, earthquake caused extensive damage with loss of 23 lives in a rural area of about 150 km2 centered just south of Laguna de Arenal in northwestern Costa Rica (fig. 1). This report summarizes the results of the writer's reconnaissance investigation of the area that was affected by the earthquake of April 13, 1973. A 4-day field study of the meizoseismal area was carried out during the period from April 28 through May 1 under the auspices of the U.S. Geological Survey. The primary objective of this study was to evaluate geologic factors that contributed to the damage and loss of life. The earthquake was also of special interest because of the possibility that it was accompanied by surface faulting comparable to that which occurred at Managua, Nicaragua, during the disastrous earthquake of December 23, 1972 (Brown, Ward, and Plafker, 1973). Such earthquake-related surface faulting can provide scientifically valuable information on active tectonic processes at shallow depths within the Middle America arc. Also, identification of active faults in this area is of considerable practical importance because of the planned construction of a major hydroelectrical facility within the meizoseismal area by the Instituto Costarricense de Electricidad (I.C.E.). The project would involve creation of a storage reservoir within the Laguna de Arenal basin and part of the Río Arenal valley with a 75 m-high earthfill dam across Río Arenal at a point about 10 km east of the outlet of Laguna de Arenal.

  10. Microbiological quality of chicken- and pork-based street-vended foods from Taichung, Taiwan, and Laguna, Philippines.

    Science.gov (United States)

    Manguiat, Lydia S; Fang, Tony J

    2013-10-01

    The microbiological quality of chicken- and pork-based street-food samples from Taichung, Taiwan's night markets (50) and Laguna, Philippines' public places (69) was evaluated in comparison to a microbiological guideline for ready-to-eat foods. Different bacterial contamination patterns were observed between 'hot-grilled' and 'cold cooked/fried' food types from the two sampling locations with 'hot grilled' foods generally showing better microbiological quality. Several samples were found to be unsatisfactory due to high levels of aerobic plate count, coliform, Escherichia coli, and Staphylococcus aureus. The highest counts obtained were 8.2 log cfu g⁻¹, 5.4 log cfu g⁻¹, 4.4 log cfu g⁻¹, and 3.9 log cfu g⁻¹, respectively, suggesting poor food hygiene practices and poor sanitation. Salmonella was found in 8% and 7% of Taichung and Laguna samples, respectively, which made the samples potentially hazardous. None of the samples was found to be positive for Listeria monocytogenes and E. coli O157, but Bacillus cereus was detected at the unsatisfactory level of 4 log cfu g⁻¹ in one Laguna sample. Antimicrobial resistance was observed for Salmonella, E. coli, and S. aureus isolates. Food preparation, cooking, and food handling practices were considered to be contributors to the unacceptable microbiological quality of the street foods. Hence, providing training on food hygiene for the street vendors should result in the improvement of the microbiological quality of street foods. The data obtained in this study can be used as input to microbial risk assessments and in identifying science-based interventions to control the hazards.

  11. Lithologic controls on mineralization at the Lagunas Norte high-sulfidation epithermal gold deposit, northern Peru

    Science.gov (United States)

    Cerpa, Luis M.; Bissig, Thomas; Kyser, Kurt; McEwan, Craig; Macassi, Arturo; Rios, Hugo W.

    2013-06-01

    The 13.1-Moz high-sulfidation epithermal gold deposit of Lagunas Norte, Alto Chicama District, northern Peru, is hosted in weakly metamorphosed quartzites of the Upper Jurassic to Lower Cretaceous Chimú Formation and in overlying Miocene volcanic rocks of dacitic to rhyolitic composition. The Dafne and Josefa diatremes crosscut the quartzites and are interpreted to be sources of the pyroclastic volcanic rocks. Hydrothermal activity was centered on the diatremes and four hydrothermal stages have been defined, three of which introduced Au ± Ag mineralization. The first hydrothermal stage is restricted to the quartzites of the Chimú Formation and is characterized by silice parda, a tan-colored aggregate of quartz-auriferous pyrite-rutile ± digenite infilling fractures and faults, partially replacing silty beds and forming cement of small hydraulic breccia bodies. The δ34S values for pyrite (1.7-2.2 ‰) and digenite (2.1 ‰) indicate a magmatic source for the sulfur. The second hydrothermal stage resulted in the emplacement of diatremes and the related volcanic rocks. The Dafne diatreme features a relatively impermeable core dominated by milled slate from the Chicama Formation, whereas the Josefa diatreme only contains Chimú Formation quartzite clasts. The third hydrothermal stage introduced the bulk of the mineralization and affected the volcanic rocks, the diatremes, and the Chimú Formation. In the volcanic rocks, classic high-sulfidation epithermal alteration zonation exhibiting vuggy quartz surrounded by a quartz-alunite and a quartz-alunite-kaolinite zone is observed. Company data suggest that gold is present in solid solution or micro inclusions in pyrite. In the quartzite, the alteration is subtle and is manifested by the presence of pyrophyllite or kaolinite in the silty beds, the former resulting from relatively high silica activities in the fluid. In the quartzite, gold mineralization is hosted in a fracture network filled with coarse alunite

  12. Postglacial history of alpine vegetation, fire, and climate from Laguna de Río Seco, Sierra Nevada, southern Spain

    Science.gov (United States)

    Anderson, R. S.; Jiménez-Moreno, G.; Carrión, J. S.; Pérez-Martínez, C.

    2011-06-01

    The Sierra Nevada of southern Spain is a landscape with a rich biological and cultural heritage. The range was extensively glaciated during the late Pleistocene. However, the postglacial paleoecologic history of the highest range in southern Europe is nearly completely unknown. Here we use sediments from a small lake above present treeline - Laguna de Río Seco at 3020 m elevation - in a paleoecological study documenting over 11,500 calendar years of vegetation, fire and climate change, addressing ecological and paleoclimatic issues unique to this area through comparison with regional paleoecological sequences. The early record is dominated by Pinus pollen, with Betula, deciduous Quercus, and grasses, with an understory of shrubs. It is unlikely that pine trees grew around the lake, and fire was relatively unimportant at this site during this period. Aquatic microfossils indicate that the wettest conditions and highest lake levels at Laguna de Río Seco occurred before 7800 cal yr BP. This is in contrast to lower elevation sites, where wettest conditions occurred after ca 7800. Greater differences in early Holocene seasonal insolation may have translated to greater snowpack and subsequently higher lake levels at higher elevations, but not necessarily at lower elevations, where higher evaporation rates prevailed. With declining seasonality after ca 8000 cal yr BP, but continuing summer precipitation, lake levels at the highest elevation site remained high, but lake levels at lower elevation sites increased as evaporation rates declined. Drier conditions commenced regionally after ca 5700 cal yr BP, shown at Laguna de Río Seco by declines in wetland pollen, and increases in high elevation steppe shrubs common today ( Juniperus, Artemisia, and others). The disappearance or decline of mesophytes, such as Betula from ca 4000 cal yr BP is part of a regional depletion in Mediterranean Spain and elsewhere in Europe from the mid to late Holocene. On the other hand

  13. Lesiones causadas por helmintos del aparato digestivo en peces estuarinos de la Laguna Tres Palos, Guerrero, México

    OpenAIRE

    Ramón Vázquez Núñez; José Ramírez Lezama; David Osorio Sarabia; Larisa Adriana Chávez Soriano; Fernando Constantino Casas

    2004-01-01

    Se realizó el presente estudio con el fi n de identificar y comparar las lesiones macro y microscópicas asociadas a helmintos en el tracto digestivo del Ariopsis guatemalensis (“cuatete”) y Eleotris picta (“alahuate”) de la Laguna de Tres Palos, Guerrero, México. En Mayo, Julio y Diciembre del 2001 se colectaron 30 peces de cada especie. A 15 individuos de cada muestra se les practicó el examen histopatológico y a los 15 restantes el examen parasitológico. Se identifi caron tres grupos de hel...

  14. The LAGUNA design study-towards giant liquid based underground detectors for neutrino physics and astrophysics and proton decay searches

    CERN Document Server

    Angus, D; Autiero, D.; Apostu, A.; Badertscher, A.; Bennet, T.; Bertola, G.; Bertola, P.F.; Besida, O.; Bettini, A.; Booth, C.; Borne, J.L.; Brancus, I.; Bujakowsky, W.; Campagne, J.E.; Danil, G.Cata; Chipesiu, F.; Chorowski, M.; Cripps, J.; Curioni, A.; Davidson, S.; Declais, Y.; Drost, U.; Duliu, O.; Dumarchez, J.; Enqvist, T.; Ereditato, A.; von Feilitzsch, F.; Fynbo, H.; Gamble, T.; Galvanin, G.; Gendotti, A.; Gizicki, W.; Goger-Neff, M.; Grasslin, U.; Gurney, D.; Hakala, M.; Hannestad, S.; Haworth, M.; Horikawa, S.; Jipa, A.; Juget, F.; Kalliokoski, T.; Katsanevas, S.; Keen, M.; Kisiel, J.; Kreslo, I.; Kudryastev, V.; Kuusiniemi, P.; Labarga, L.; Lachenmaier, T.; Lanfranchi, J.C.; Lazanu, I.; Lewke, T.; Loo, K.; Lightfoot, P.; Lindner, M.; Longhin, A.; Maalampi, J.; Marafini, M.; Marchionni, A.; Margineanu, R.M.; Markiewicz, A.; Marrodan-Undagoita, T.; Marteau, J.E.; Matikainen, R.; Meindl, Q.; Messina, M.; Mietelski, J.W.; Mitrica, B.; Mordasini, A.; Mosca, L.; Moser, U.; Nuijten, G.; Oberauer, L.; Oprina, A.; Paling, S.; Pascoli, S.; Patzak, T.; Pectu, M.; Pilecki, Z.; Piquemal, F.; Potzel, W.; Pytel, W.; Raczynski, M.; Rafflet, G.; Ristaino, G.; Robinson, M.; Rogers, R.; Roinisto, J.; Romana, M.; Rondio, E.; Rossi, B.; Rubbia, A.; Sadecki, Z.; Saenz, C.; Saftoiu, A.; Salmelainen, J.; Sima, O.; Slizowski, J.; Slizowski, K.; Sobczyk, J.; Spooner, N.; Stoica, S.; Suhonen, J.; Sulej, R.; Szarska, M.; Szeglowski, T.; Temussi, M.; Thompson, J.; Thompson, L.; Trzaska, W.H.; Tippmann, M.; Tonazzo, A.; Urbanczyk, K.; Vasseur, G.; Williams, A.; Winter, J.; Wojutszewska, K.; Wurm, M.; Zalewska, A.; Zampaolo, M.; Zito, M.

    2010-01-01

    The feasibility of a next generation neutrino observatory in Europe is being considered within the LAGUNA design study. To accommodate giant neutrino detectors and shield them from cosmic rays, a new very large underground infrastructure is required. Seven potential candidate sites in different parts of Europe and at several distances from CERN are being studied: Boulby (UK), Canfranc (Spain), Fr\\'ejus (France/Italy), Pyh\\"asalmi (Finland), Polkowice-Sieroszowice (Poland), Slanic (Romania) and Umbria (Italy). The design study aims at the comprehensive and coordinated technical assessment of each site, at a coherent cost estimation, and at a prioritization of the sites within the summer 2010.

  15. Society and Environment Interaction. The Environment of the Laguna de los Tollos (Western Andalusia, 13th-15th Centuries

    Directory of Open Access Journals (Sweden)

    Emilio MARTÍN GUTIÉRREZ

    2014-12-01

    Full Text Available Environment of the Laguna de los Tollos is studied between 13th and 15th Centuries. The research, which aims to analyse the interaction environment-society, is part of a project that will deepen the knowledge of wetlands in this geographical area. In these ecosystems rural communities took advantage with their farmland for hunting, herding, fishing and gathering resources in riparian areas. The chosen chronological period includes a wide range of changes that had a direct impact on the management and organization of rural landscapes.

  16. La docencia del área de Toxicología de la Universidad de La Laguna

    OpenAIRE

    A. J. Gutiérrez Fernández; C. Rubio Armendáriz; G. Luis González; C Hernández Sánchez; D. González- Weller; J. M. Caballero Mesa; A. Hardisson de la Torre

    2012-01-01

    La docencia de Toxicología en la Universidad de La Laguna (ULL) se integra en diversas Licenciaturas y Grados tales como Farmacia, Ciencia y Tecnología de los Alimentos (CTA), Medicina, Náutica y Transporte Marítimo y el Máster Oficial de Seguridad y Calidad de los Alimentos. En la Licenciatura de Farmacia en la ULL, el Área de Toxicología imparte la asignatura troncal Toxicología de 7 créditos y dos asignaturas optativas, Drogodependencias y Toxicología Clínica y Laboral, de 4,5 créditos...

  17. Producción espacial y temporal de hojarasca del manglar en la laguna Barra de Navidad, Jalisco, México

    OpenAIRE

    Mendoza-Morales, Alma J.; González-Sansón, Gaspar; Aguilar-Betancourt, Consuelo

    2016-01-01

    La laguna de Barra de Navidad es un humedal costero de importancia internacional (sitio RAMSAR) y está incluida entre los 81 sitios prioritarios de manglar de México. Una de las características de mayor valor de la laguna, es la presencia de bosques de mangle en buen estado de conservación. El objetivo de nuestro trabajo, fue medir la producción de hojarasca del manglar y los factores ambientales que pueden influir en su dinámica. El manglar fue dividido en siete zonas y las recolectas de hoj...

  18. Aproximación ecotoxicológica a la contaminación por metales pesados en la laguna costera del Mar Menor

    OpenAIRE

    Marín Guirao, Lázaro

    2007-01-01

    El objetivo de la Tesis es obtener una visión de la situación actual de la laguna costera del Mar Menor en relación con la contaminación por metales pesados procedentes de actividades mineras mediante el empleo de herramientas ecotoxicológicas. Comienza con el estudio de la entrada de residuos mineros en el ecosistema, su distribución en las aguas de la laguna así como los efectos tóxicos asociados. Continua valorando la biodisponibilidad de los metales contenidos en los sedimentos lagunares ...

  19. Early and mid-Holocene age for the Tempanos moraines, Laguna San Rafael, Patagonian Chile

    Science.gov (United States)

    Harrison, Stephan; Glasser, Neil F.; Duller, Geoff A. T.; Jansson, Krister N.

    2012-01-01

    Data about the nature and timing of Holocene events from the Southern Hemisphere, especially in southern South America, are required to provide insight into the extent and nature of past climate change in a region where land-based records are restricted. Here we present the first use of single grain Optically Stimulated Luminescence (OSL) dating of a moraine sequence recording glacial advance along the western side of the Patagonian Icefields. Dates from the Tempanos moraines at Laguna San Rafael (LSR) show that the San Rafael Glacier (SRG) advanced to maximum Holocene positions during the period 9.3 to 9.7 ka and at 5.7 ka. Outwash lying beneath the moraine in its northern portion, dated to 7.7 ka, indicates that the glacier front was also advanced at this time. Since these advances span both the regional early Holocene warm-dry phase (11.5 ka to 7.8 ka) and the subsequent cooling and rise in precipitation in the mid-late Holocene (since 6.6 ka) we infer that the advances of the SRG are not simply climate-driven, but that the glacier has also probably responded strongly to non-climatic stimuli such as internal ice dynamics and the transition between calving and non-calving. Many westwards-flowing glaciers in Patagonia were probably calving during much of the Late Pleistocene and Holocene, so we conclude that establishing robust glacial chronologies where climatic and non-climatic factors cannot be distinguished is likely to remain a challenge.

  20. Nuove ricerche subacquee nella laguna di Santa Giusta (OR (campagna del 2009-2010

    Directory of Open Access Journals (Sweden)

    Carla Del Vais

    2012-07-01

    Full Text Available Le ricerche avviate nel 2005 nella laguna di Santa Giusta (OR stanno rivelando la presenza di contesti archeologici di età fenicio-punica di eccezionale rilevanza. In uno di questi, localizzato a circa 800 m dall’attuale linea di riva, è stato condotto, a partire dal 2006, uno scavo subacqueo, ancora in corso. Sono stati recuperati numerosi materiali ceramici, in larga parte rappresentati da anfore commerciali, ma anche da ceramica domestica e, più raramente, di carattere funerario e cultuale (VI-III/II sec. a.C.. In vari casi le anfore contenevano resti ossei animali, più spesso di ovicaprini, con evidenti tracce di macellazione; le condizioni anossiche garantite dal substrato limoso hanno favorito la conservazione di materiali organici, tra i quali pigne, semi di diverse specie e legni, prevalentemente lavorati, alcuni ancora in connessione. Research undertaken in 2005 in the lagoon of Santa Giusta (OR is revealing the presence of archaeological contexts of Phoenician-Punic date of exceptional importance. In one of these, located about 800 m from the current shoreline, an underwa­ter excavation was conducted since 2006; it is still in progress. Much pottery has been recovered, mostly represented by transport amphoras, but also by domestic pottery and, more rarely, ceramics associated with funerary and cultic use (6th-2nd century BC. In several cases the amphoras contained animal remains, most often of ovicaprines, with clear traces of slaughter; the anaerobic condi­tions guaranteed by the silty substrate have favoured the preservation of organic materials, including pine cones, seeds of different species and wood, mostly worked and some still joined together.

  1. Estructura del macrobentos de la laguna de Paca, Junín

    Directory of Open Access Journals (Sweden)

    Pedro Huamán

    2013-06-01

    Full Text Available Se caracterizó la estructura comunitaria del macrobentos de la laguna de Paca ubicada a 3364 msnm, a 11º 45 S y 75º 30’ W en el departamento de Junín-Perú. También se analizaron los principales factores físicos y químicos del agua y sedimentos que condicionan dicha estructura. Los muestreos se realizaron en el año 2000 en 8 estaciones, distribuidas en la zona litoral (5 y pelágica (3. En cada estación se tomaron muestras de agua cercana al fondo y de sedimentos para analizar los parámetros físicos, químicos y biológicos de la comunidad del macrobentos. Los datos fueron sometidos a pruebas univariadas y multivariadas para determinar el grado de interacción de los diversos factores con las variables biológicas. La diversidad del macrobentos es baja y muestra valores de diversidad menores a 1,5 y el número de especies menores a 11 especies. La abundancia varía en valores que van desde los 16 hasta 176 individuos/0,04 m2 . Tubifex tubifex y Chironomus sp. fueron las especies más resistentes a los altos valores de materia orgánica (35,22 a 38,28% y bajos valores de oxígeno disuelto (1 a 2 mg/L, lo que constituye indicadores biológicos de eutroficación.

  2. Disentangling High Frequency Climate Oscillations In A Volcanic Setting Laguna Lejia, Chile

    Science.gov (United States)

    Saltzman, S. H.; Ukstins Peate, I.; Giralt, S.; Peate, D. W.; van Alderwerelt, B. M.

    2015-12-01

    Our understanding of the tropics response to periods of rapid climate change such as CAPE I and the Younger Dryas is limited. Laguna Lejia (23°30'0" S 67°42'0" E ~4,300m asl), Chile is a small alkaline paleolake located in the central Altiplano. The volcanoes Lascar, Chiliques, Aguas Calientes and Acamarachi surround it. 1-3 mm laminations in calcareous clay sediments deposited on the southern terrace of Lejia record high-resolution chemical variability in the lake. Preliminary U-Th ages range from 19,567 +739/- 734 yr to 4208 +431/-429 yr, indicating that the Lejia terrace deposits span both CAPE I and the Younger Dryas, periods of rapid global climate change. Changes in the major and trace element composition, δ18O and δ13 C isotopic ratios, and the amount of Li, Mg, Ca, and Sr that can be readily leached from high magnesium smectite clays provide a direct proxy for hydrologic fluctuations. A climate signal can be detected through reoccurring trends in the chemical variability of these sediments; however, the detection of this signal is complicated by interaction with surrounding volcanic edifices. Statistical methods such as PCA analyses using R have been implemented to separate groupings of volcanic controlled elemental fluctuations (Fe, Zr, Nd, Ti, and Al) from ones under the influence of climate. Spectral analyses have been applied to high-resolution major element data collected on Lejia's paleoshores tufa deposits. Data was collected on Ca, Mg and As at .5 um intervals using a Jeol JXA- 8230 Electron Microprobe at the University of Iowa, Earth and Environmental Sciences. These analyses provided statistical evidence for cyclisity at intervals of 5-15 um and 75-150 um in the banding of the tufas. While previous literature attributes the larger bands to annual chemical cycles the origin of the smaller bands is currently under investigation.

  3. Preliminary evaluation of the profitability indexes of the Laguna Verde nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-10-15

    The Laguna Verde nuclear power plant of the Federal Commission of Electricity has an installed capacity of 1,350 MW and unit 1 started commercial operation in 1990 and unit 2 in 1995. This paper is a synthesis of the results of a preliminary evaluation of the expected profitability indexes of the power plant during an economic lifetime of 40 years. The following data was used as input to the evaluation model prescribed by the Finance and Public Credit Secretary for public investment projects. Unit investment cost: 3,500 US D/k W; Fixed operation and maintenance cost: 54.{sup 45} US D/year-k W; Variable operation and maintenance cost: 0.{sup 38} US D/M Wh; Nuclear fuel cycle cost: 10.{sup 28} US D/M Wh; Lifetime capacity factor: 85%; Discount rate: 12.0% per year; Sale price of electricity to the interconnected electric system: 80.{sup 75} US D/M Wh. The output of the evaluation model is the following: Cost of electricity generated: 60.{sup 2}1 US D/M Wh; fixed cost 49.{sup 55} US D/M Wh; variable cost 10.{sup 66} US D/M Wh; Internal rate of return (Irr): 18.0%; Benefit to cost quotient (B/C): 1.341. A very systematic sensitivity analysis was done, that shows that the cost is very sensitive to the capacity factor and to the investment cost, but is very insensitive to the fixed operation and maintenance cost and to the nuclear fuel cost. Finally, a comparison was made to the evaluation of the profitability indexes of a natural gas fired combined cycle power plant. (Author)

  4. Dynamics of a large, restless, rhyolitic magma system at Laguna del Maule, southern Andes, Chile

    Science.gov (United States)

    Singer, Brad S.; Andersen, Nathan L.; Le Mével, Hélène; Feigl, Kurt L.; DeMets, Charles; Tikoff, Basil; Thurber, Clifford H.; Jicha, Brian R.; Cardonna, Carlos; Córdova, Loreto; Gil, Fernando; Unsworth, Martyn J.; Williams-Jones, Glyn; Miller, Craig W.; Fierstein, Judith; Hildreth, Edward; Vazquez, Jorge A.

    2014-01-01

    Explosive eruptions of large-volume rhyolitic magma systems are common in the geologic record and pose a major potential threat to society. Unlike other natural hazards, such as earthquakes and tsunamis, a large rhyolitic volcano may provide warning signs long before a caldera-forming eruption occurs. Yet, these signs—and what they imply about magma-crust dynamics—are not well known. This is because we have learned how these systems form, grow, and erupt mainly from the study of ash flow tuffs deposited tens to hundreds of thousands of years ago or more, or from the geophysical imaging of the unerupted portions of the reservoirs beneath the associated calderas. The Laguna del Maule Volcanic Field, Chile, includes an unusually large and recent concentration of silicic eruptions. Since 2007, the crust there has been inflating at an astonishing rate of at least 25 cm/yr. This unique opportunity to investigate the dynamics of a large rhyolitic system while magma migration, reservoir growth, and crustal deformation are actively under way is stimulating a new international collaboration. Findings thus far lead to the hypothesis that the silicic vents have tapped an extensive layer of crystal-poor, rhyolitic melt that began to form atop a magmatic mush zone that was established by ca. 20 ka with a renewed phase of rhyolite eruptions during the Holocene. Modeling of surface deformation, magnetotelluric data, and gravity changes suggest that magma is currently intruding at a depth of ~5 km. The next phase of this investigation seeks to enlarge the sets of geophysical and geochemical data and to use these observations in numerical models of system dynamics.

  5. El uso hegemónico del agua en la laguna Chignahuapan 1940-1969

    Directory of Open Access Journals (Sweden)

    María Verónica Ibarra García

    2010-01-01

    Full Text Available Este artículo analiza los cambios en el uso predominante del agua, desde la geografía política, en los municipios de Almoloya del Río, San Mateo Texcalyacac y Santa Cruz Atizapan, localizados en la cuenca alta del Lerma, básicamente de los años cuarenta a los sesenta del siglo XX. Serán considerados elementos sociales, económicos y políticos que definen las condiciones de la naturaleza, esta propuesta crítica de la geografía política, se desarrolla en oposición a las vertientes de la naturaleza prístina, en contraste con esta corriente, planteamos el problema del uso-apropiación del agua como una segunda naturaleza, para la cual las relaciones de poder y el modelo de sustitución de importaciones y la consecuente urbanización e industrialización exigen la extracción y trasvase del agua de la cuenca alta de Lerma a la ciudad de México. La parcial desecación de la laguna de Chignahuapan es la manifestación ambiental de una forma de apropiación y uso del agua que responde a un modelo de desarrollo, con intereses precisos que iniciaron la producción del espacio nacional, dentro del sistema capitalista mexicano bajo un régimen político autoritario.

  6. Uso de lagunas algales de alta tasa para tratamiento de aguas residuales

    Directory of Open Access Journals (Sweden)

    Víctor Alfonso Cerón Hernández

    2015-01-01

    Full Text Available Se han propuesto muchos sistemas para la descontaminación de las aguas residuales domésticas, industriales y lixiviados. Actualmente se espera tratar las aguas residuales y derivar un beneficio económico-ambiental. Es en este contexto que los sistemas algales de alta tasa se propusieron inicialmente para el tratamiento de aguas residuales domésticas. Sin em - bargo, la investigación realizada alrededor de esta tecnología ha mostrado ventajas y beneficios que no se tenían contemplados inicialmente. En la actualidad se están realizando implementaciones en el tratamiento de las aguas residuales, buscando la producción de biocombustibles, bio - masa algal para alimento (animal y humano, la obtención de productos farmacéuticos y la bioprospección de las algas. Adicional a esto, se está investigando sobre la captura y reducción del dióxido de carbono ( CO 2 atmosférico, mecanismos de eliminación de contaminantes específicos y la optimización de la hidrobiología del sistema. Sin embargo, hace falta información sobre la función y la ecología de las algas y la relación alga/ bacteria, efecto del comportamiento hidrodinámico de la laguna sobre la producción algal, el efecto de las variables ambientales del trópico en el desempeño del sistema y el desarrollo de criterios de diseño para zonas tropicales.

  7. Perspectives of the central Laguna Verde after Fukushima for the period 2012 at the 2015 in operation and maintenance; Perspectivas de la central Laguna Verde despues de Fukushima para el periodo 2012 al 2015 en operacion y mantenimiento

    Energy Technology Data Exchange (ETDEWEB)

    Rivera C, A., E-mail: arr99999@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km 42.5, Veracruz (Mexico)

    2012-10-15

    The Nuclear Power Plants Management of the Federal Commission of Electricity in Mexico by means an internal analysis confronts the threat to the nuclear industry of the event of Fukushima that affected the public opinion, and the emission of new regulations. This situation demands to improve the results of the operation and maintenance of the nuclear power plant of Laguna Verde, to contribute value with their excellence in the acting to the nuclear option in Mexico. The internal analysis defined with clarity the perspectives based on weaknesses and strengths of the operation (monitoring and control of on-line parameters), and in the maintenance (sustained by the planning), enriched with the external experiences emitted by the institutes INPO and WANO for the nuclear industry, with all this strategic objectives 2012 to 2015 were presented and the initiatives as the extension of the useful life to 20 years more, as well as the focused actions to diminish the threat that the event of Fukushima influenced negatively in the public opinion, by means the diffusion of the good results that can be obtained in the nuclear power plant of Laguna Verde between 2012 and 2015, taking advantage of its modernized power of 810 MW-hour for each generating unit, doing visible that the Project of Extended Power Increase is a generation reality of 120% of the original value, to be able to enter at the excellence levels of the nuclear world. (Author)

  8. Application of six sigma to reloads design of the Laguna Verde Central with length until 17 days; Aplicacion de seis sigma para disenar recargas de la Central Laguna Verde con duracion hasta de 17 dias

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa G, J.M. [Comision Federal de Electricidad, Central Laguna Verde, Subgerencia General de Operacion, Planeacion, Veracruz (Mexico)]. e-mail: mespinos@cfe.gob.mx

    2007-07-01

    The more important value in the Laguna Verde Central it is the safety. The international experience it confirms us that the more safe plants its are those more productive, this conclusion and reasoning indicate to the power station that we are in the correct road, improving the acting we will obtain that greater interest for us in the Laguna Verde Central (to increase the safety) and as added value to be able to be one of the best business for the Federal Commission of Electricity. With a future vision and commitment of high acting was integrated in an external place to all the area headquarters: (Maintenance, Planning, Operation, Parts of Reserve, Finances, Contracts, Supplies, Warehouse, design Engineering, place Engineering, engineering of systems, radiological Protection, etc.) to carry out a combined work with the unique challenge of drifting with the biggest level detail the program of a recharge and certainly to get ready to achieve their execution (all this without omitting any consideration for smaller or simpler than it seemed), looking for high quality in the works, with and bigger level of safety, with the minimum possible dose, the more reasonable cost and considering a new concept of human character, to achieve the above-mentioned without the participant personnel's stress, with the premise that a good plan and commitment of all the only one that it can bring us as result it is the success of the whole organization. (Author)

  9. 15 years of production of electric energy of the Laguna Verde power plant, its plans and future; 15 anos de produccion de energia electrica de la Central Laguna Verde, sus planes y futuro

    Energy Technology Data Exchange (ETDEWEB)

    Rivera C, A. [CFE, Central Laguna Verde, Km. 42.5 Carretera Cardel-Nautla, Veracruz (Mexico)]. e-mail: arr99999@cfe.gob.mx

    2005-07-01

    In the year 2005 Laguna Verde power plant reaches 15 years of producing electric power in Mexico arriving to but of 100 million Megawatts-hour from their beginning of commercial activities. The Unit 1 that entered at July 29, 1990 and the Unit 2 at April 10, 1995, obtaining the Disposability Factors from their origin is: 84.63% in Unit 1 and 83.67% in Unit 2. The march of the X XI century gives big challenges of competition to the Laguna Verde Central, with the possible opening of the electric market to private investment, for their Goals and Objectives of a world class company, taking the evaluation system and qualification of the World Association of Nuclear Operators (WANO) that promotes the Excellence in the operation of the nuclear power stations in all their partners. This Association supports the development of programs that allow the monitoring of the behavior in Safety Culture, Human fulfilment, Equipment reliability, Industrial Safety, Planning, Programming and Control, Personalized Systematic Training, and the use of the Operational experience in the daily tasks. The present work tries to explain the system of evaluation/qualification of WANO, the definition of Goals and Objectives to reach the excellence and of the programs, it will present the Program of the Reliability of Equipment with its main actions the productivity. (Author)

  10. Estimation of fast neutron fluence in steel specimens type Laguna Verde in TRIGA Mark III reactor; Estimacion de la fluencia de neutrones rapidos en probetas de acero tipo Laguna Verde en el reactor Triga Mark III

    Energy Technology Data Exchange (ETDEWEB)

    Galicia A, J.; Francois L, J. L. [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Aguilar H, F., E-mail: blink19871@hotmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2015-09-15

    The main purpose of this work is to obtain the fluence of fast neutrons recorded within four specimens of carbon steel, similar to the material having the vessels of the BWR reactors of the nuclear power plant of Laguna Verde when subjected to neutron flux in a experimental facility of the TRIGA Mark III reactor, calculating an irradiation time to age the material so accelerated. For the calculation of the neutron flux in the specimens was used the Monte Carlo code MCNP5. In an initial stage, three sheets of natural molybdenum and molybdenum trioxide (MoO{sub 3}) were incorporated into a model developed of the TRIGA reactor operating at 1 M Wth, to calculate the resulting activity by setting a certain time of irradiation. The results obtained were compared with experimentally measured activities in these same materials to validate the calculated neutron flux in the model used. Subsequently, the fast neutron flux received by the steel specimens to incorporate them in the experimental facility E-16 of the reactor core model operating at nominal maximum power in steady-state was calculated, already from these calculations the irradiation time required was obtained for values of the neutron flux in the range of 10{sup 18} n/cm{sup 2}, which is estimated for the case of Laguna Verde after 32 years of effective operation at maximum power. (Author)

  11. Validation of the thermal balance of Laguna Verde turbine under conditions of extended power increase; Validacion del balance termico de turbina de Laguna Verde en condiciones de aumento de potencia extendido

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda G, M. A.; Cruz B, H. J.; Mercado V, J. J.; Cardenas J, J. B.; Garcia de la C, F. M., E-mail: miguel.castaneda01@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km 42.5, Alto Lucero, Veracruz (Mexico)

    2012-10-15

    The present work is a continuation of the task: Modeling of the vapor cycle of Laguna Verde with the PEPSE code to conditions of thermal power licensed at present (2027 MWt) in which the modeling of the vapor cycle of the nuclear power plant of Laguna Verde was realized with PEPSE code (Performance Evaluation of Power System Efficiencies). Once reached the conditions of nominal operation of extended power increase, operating both units to 2371 MWt; after the tests phase of starting-up and operation is necessary to carry out a verification of the proposed design of the vapor cycle for the new operation conditions. All this, having in consideration that the vapor cycle designer only knows the detail of the prospective performance of the main turbine, for all the other components (for example pumps, heat inter changers, valves, reactor, humidity separators and re-heaters, condensers, etc.) makes generic suppositions based on engineering judgment. This way carries out the calculations of thermal balance to determine the guaranteed gross power. The purpose of the present work is to comment the detail of the validation carried out of the specific thermal balance (thermal kit) of the nuclear power plant, making use of the design characteristics of the different components that conform the vapor cycle. (Author)

  12. Hidroquímica de la laguna de Tíscar (Córdoba, España

    Directory of Open Access Journals (Sweden)

    Giráldez Cervera, J. V.

    1990-04-01

    Full Text Available The Natural Reserve of Westlands of Córdoba province is formed by Tiscar playa-lake and other five closed basin lagoons. The results obteined in the present work show that its basin are located on triassic saline materials, and its dissolution to originate from the ground water characteristics. The «Geochem» program application and other analitical methods show the presence of gypsum and halite minerals and the absence of calcite and dolomite in this playa-lake ecosystem.La laguna de Tíscar es uno de los seis espacios lagunares que constituyen la Reserva Natural de las Zonas húmedas de la provincia de Córdoba. De los resultados obtenidos en el presente trabajo se deduce la ubicación de dicha laguna sobre depósitos salinos triásicos, siendo la disolución de este sustrato la fuente originaria de los iones presentes en las aguas subterráneas que la alimentan. La aplicación del programa «Geochem» y la de otros métodos analíticos tradicionales, ponen de manifiesto la presencia en este medio lagunar de yeso y halita como especies minerales mayoritarias, no detectándose en ningún caso la presencia de calcita y dolomita.

  13. Distribution and community structure of ichthyoplankton in Laguna Madre seagrass meadows: Potential impact of seagrass species change

    Science.gov (United States)

    Tolan, J.M.; Holt, S.A.; Onuf, C.P.

    1997-01-01

    Seasonal ichthyoplankton surveys were made in the lower Laguna Madre, Texas, to compare the relative utilization of various nursery habitats (shoal grass, Halodule wrightii; manatee grass, Syringodium filiforme;, and unvegetated sand bottom) for both estuarine and offshore-spawned larvae. The species composition and abundance of fish larvae were determined for each habitat type at six locations in the bay. Pushnet ichthyoplankton sampling resulted in 296 total collections, yielding 107,463 fishes representing 55 species in 24 families. A broad spectrum of both the biotic and physical habitat parameters were examined to link the dispersion and distribution of both pre-settlement and post-settlement larvae to the utilization of shallow seagrass habitats. Sample sites were grouped by cluster analysis (Ward's minimum variance method) according to the similarity of their fish assemblages and subsequently examined with a multiple discriminant function analysis to identify important environmental variables. Abiotic environmental factors were most influential in defining groups for samples dominated by early larvae, whereas measures of seagrass complexity defined groups dominated by older larvae and juveniles. Juvenile-stage individuals showed clear habitat preference, with the more shallow Halodule wrightii being the habitat of choice, whereas early larvae of most species were widely distributed over all habitats. As a result of the recent shift of dominance from Halodule wrightii to Syringodium filiforme, overall reductions in the quality of nursery habitat for fishes in the lower Laguna Madre are projected.

  14. Ang Social Network sa Facebook ng mga Taga-Batangas at ng mga Taga-Laguna: Isang Paghahambing

    Directory of Open Access Journals (Sweden)

    Jaderick P. Pabico

    2013-12-01

    Full Text Available Online social networking (OSN has become of great influence to Filipinos, where Facebook, Twitter, LinkedIn, Google+, and Instagram are among the popular ones. Their popularity, coupled with their intuitive and interactive use, allow one's personal information such as gender, age, address, relationship status, and list of friends to become publicly available. The accessibility of information from these sites allow, with the aid of computers, for the study of a wide population's characteristics even in a provincial scale. Aside from being neighbouring locales, the respective residents of Laguna and Batangas both derive their livelihoods from two lakes, Laguna de Bay and Taal Lake. Both residents experience similar problems, such as that, among many others, of fish kill. The goal of this research is to find out similarities in their respective online populations, particularly that of Facebook's. With the use of computational dynamic social network analysis (CDSNA, we found out that the two communities are similar, among others, as follows: both populations are dominated by single young female; Homophily was observed when choosing a friend in terms of age (i.e., friendships were created more often between people whose ages do not differ by at most five years; and Heterophily was observed when choosing friends in terms of gender (i.e., more friendships were created between a male and a female than between both people of the same gender. This paper also presents the differences in the structure of the two social networks, such as degrees of separation and preferential attachment.

  15. El proyecto de recuperación de la laguna de La Nava: una iniciativa de éxito

    Directory of Open Access Journals (Sweden)

    Fernando Jubete

    2004-01-01

    Full Text Available La riqueza ornítica de una de las tres lagunas interiores más importantes de España, La Nava, hizo posible que llegaran los fondos necesarios para que en 1990 las aguas de un río volviesen de nuevo a inundar 60 ha de ella. Las obras realizadas en esta primera intervención trataron de anular los desagües de la red de canales y acequias existentes. Posteriormente, las acciones contempladas en un proyecto de la UE incluyeron la compra y arrendamiento de terrenos, trabajos de restauración dentro y fuera del vaso lagunar, actividades de gestión y uso público. El proyecto de recuperación de la Nava ha conseguido regenerar 300 ha de la antigua laguna y está generando unos interesantes recursos económicos directos e indirectos, derivados principalmente del turismo. La actual crisis que está sufriendo el sector agrario, especialmente notoria en la comarca de Tierra de Campos, nos enseña ahora que decisiones políticas tan arriesgadas como la destrucción de un enclave natural tan importante como la Nava deben contar con informes serios y rigurosos sobre cuales son las perspectivas de futuro.

  16. Congener-specific polychlorinated biphenyl patterns in eggs of aquatic birds from the lower Laguna Madre, Texas

    Science.gov (United States)

    Mora, Miguel A.

    1996-01-01

    Eggs from four aquatic bird species nesting in the Lower Laguna Madre, Texas, were collected to determine differences and similarities in the accumulation of congener-specific polychlorinated biphenyls (PCBs) and to evaluate PCB impacts on reproduction. Because of the different toxicities of PCB congeners, it is important to know which congeners contribute most to total PCBs. The predominant PCB congeners were 153, 138, 180, 110, 118, 187, and 92. Collectively, congeners 153, 138, and 180 accounted for 26 to 42% of total PCBs. Congener 153 was the most abundant in Caspian terns (Sterna caspia) and great blue herons (Ardea herodias) and congener 138 was the most abundant in snowy egrets (Egretta thula) and tricolored herons (Egretta tricolor). Principal component analysis indicated a predominance of higher chlorinated biphenyls in Caspian terns and great blue herons and lower chlorinated biphenyls in tricolored herons. Snowy egrets had a predominance of pentachlorobiphenyls. These results suggest that there are differences in PCB congener patterns in closely related species and that these differences are more likely associated with the species' diet rather than metabolism. Total PCBs were significantly greater (p Laguna Madre were below concentrations known to affect bird reproduction.

  17. Congener-specific polychlorinated biphenyl patterns in eggs of aquatic birds from the Lower Laguna Madre, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Mora, M.A. [Texas A and M Univ., College Station, TX (United States)

    1996-06-01

    Eggs from four aquatic bird species nesting in the Lower Laguna Madre, Texas, were collected to determine differences and similarities in the accumulation of congener-specific polychlorinated biphenyls (PCBs) and to evaluate PCB impacts on reproduction. Because of the different toxicities of PCB congeners, it is important to know which congeners contribute most to total PCBs. The predominant PCB congeners were 153, 138, 180, 110, 118, 187, and 92. Collectively, congeners 153, 138, and 180 accounted for 26 to 42% of total PCBs. Congener 153 was the most abundant in Caspian terns (Sterna caspia) and great blue herons (Ardea herodias) and congener 138 was the most abundant in snowy egrets (Egretta thula) and tricolored herons (Egretta tricolor). Principal component analysis indicated a predominance of higher chlorinated biphenyls in Caspian terns and great blue herons and lower chlorinated biphenyls in tricolored herons. Snowy egrets had a predominance of pentachlorobiphenyls. These results suggest that there are differences in PCB congener patterns in closely related species and that these differences are more likely associated with the species` diet rather than metabolism. Total PCBs were significantly greater (p < 0.05) in Caspian terns than in the other species. Overall, PCBs in eggs of birds from the Lower Laguna Madre were below concentrations known to affect bird reproduction.

  18. Estimated natural streamflow in the Rio San Jose upstream from the pueblos of Acoma and Laguna, New Mexico

    Science.gov (United States)

    Risser, D.W.

    1982-01-01

    The development of surface and ground water, which began about 1870 in the upper Rio San Jose drainage basin, has decreased the flow of the Rio San Jose on the Pueblo of Acoma and the Pueblo of Laguna. The purpose of this study was to estimate the natural streamflow in the Rio San Jose that would have entered the pueblos if no upstream water development had taken place. Estimates of natural flow were based upon streamflow and precipitation records, historical accounts of streamflow, records of irrigated acreage, and empirically-derived estimates of the effects on streamflow of Bluewater Lake, groundwater withdrawals, and irrigation diversions. Natural streamflow in the Rio San Jose at the western boundary of the Pueblo of Acoma is estimated to be between 13,000 and 15,000 acre-feet per year, based on 55 years of recorded and reconstructed streamflow data from water years 1913 to 1972. Natural streamflow at the western boundary of the Pueblo of Laguna is estimated to be between 17 ,000 and 19,000 acre-feet per year for the same period. The error in these estimates of natural streamflow is difficult to assess accurately, but it probably is less than 25 percent. (USGS)

  19. Modeling of the vapor cycle of Laguna Verde with the PEPSE code to conditions of thermal power licensed at present (2027 MWt); Modelado del ciclo de vapor de Laguna Verde con el codigo PEPSE a condiciones de potencia termica actualmente licenciada (2027 MWt)

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda G, M. A.; Maya G, F.; Medel C, J. E.; Cardenas J, J. B.; Cruz B, H. J.; Mercado V, J. J., E-mail: miguel.castaneda01@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km 42.5, Veracruz (Mexico)

    2011-11-15

    By means of the use of the performance evaluation of power system efficiencies (PEPSE) code was modeled the vapor cycle of the nuclear power station of Laguna Verde to reproduce the nuclear plant behavior to conditions of thermal power, licensed at present (2027 MWt); with the purpose of having a base line before the implementation of the project of extended power increase. The model of the gauged vapor cycle to reproduce the nuclear plant conditions makes use of the PEPSE model, design case of the vapor cycle of nuclear power station of Laguna Verde, which has as main components of the model the great equipment of the vapor cycle of Laguna Verde. The design case model makes use of information about the design requirements of each equipment for theoretically calculating the electric power of exit, besides thermodynamic conditions of the vapor cycle in different points. Starting from the design model and making use of data of the vapor cycle measured in the nuclear plant; the adjustment factors were calculated for the different equipment s of the vapor cycle, to reproduce with the PEPSE model the real vapor cycle of Laguna Verde. Once characterized the model of the vapor cycle of Laguna Verde, we can realize different sensibility studies to determine the effects macros to the vapor cycle by the variation of certain key parameters. (Author)

  20. Selected Hydrologic, Water-Quality, Biological, and Sedimentation Characteristics of Laguna Grande, Fajardo, Puerto Rico, March 2007-February 2009

    Science.gov (United States)

    Soler-López, Luis R.; Santos, Carlos R.

    2010-01-01

    Laguna Grande is a 50-hectare lagoon in the municipio of Fajardo, located in the northeasternmost part of Puerto Rico. Hydrologic, water-quality, and biological data were collected in the lagoon between March 2007 and February 2009 to establish baseline conditions and determine the health of Laguna Grande on the basis of preestablished standards. In addition, a core of bottom material was obtained at one site within the lagoon to establish sediment depositional rates. Water-quality properties measured onsite (temperature, pH, dissolved oxygen, specific conductance, and water transparency) varied temporally rather than areally. All physical properties were in compliance with current regulatory standards established for Puerto Rico. Nutrient concentrations were very low and in compliance with current regulatory standards (less than 5.0 and 1.0 milligrams per liter for total nitrogen and total phosphorus, respectively). The average total nitrogen concentration was 0.28 milligram per liter, and the average total phosphorus concentration was 0.02 milligram per liter. Chlorophyll a was the predominant form of photosynthetic pigment in the water. The average chlorophyll-a concentration was 6.2 micrograms per liter. Bottom sediment accumulation rates were determined in sediment cores by modeling the downcore activities of lead-210 and cesium-137. Results indicated a sediment depositional rate of about 0.44 centimeter per year. At this rate of sediment accretion, the lagoon may become a marshland in about 700 to 900 years. About 86 percent of the community primary productivity in Laguna Grande was generated by periphyton, primarily algal mats and seagrasses, and the remaining 14 percent was generated by phytoplankton in the water column. Based on the diel studies the total average net community productivity equaled 5.7 grams of oxygen per cubic meter per day (2.1 grams of carbon per cubic meter per day). Most of this productivity was ascribed to periphyton and macrophytes

  1. Diseño de Lagunas de Estabilización en Serie con Diferentes configuraciones. (Caso Comarca Lagunera Estado de Durango, México.

    Directory of Open Access Journals (Sweden)

    Facundo Cortés Martínez

    2011-01-01

    Full Text Available Una de las principales desventajas en un sistema de tratamiento de lagunas de estabilización es el requerimiento del terreno, es por ello que en el diseño se deben analizar varias propuestas. El objetivo del presente estudio fue realizar un análisis comparativo de resultados en el diseño de una planta de tratamiento a base de lagunas. Lo indicado incluyendo dos arreglos en serie, el primero: anaerobia, facultativa y maduración. En el segundo caso, facultativa y maduración. Se diseñó una planta de tratamiento para una comunidad rural localizada en el municipio de Gómez Palacio, Dgo. Los resultados del primer arreglo muestran un área menor del 17.11 % y un tiempo de retención de 21.68 días. Los dos esquemas analizados cumplen satisfactoriamente con los límites máximos permisibles de concentración de contaminantes que indica la normatividad. El primer arreglo de lagunas de estabilización es el que se recomienda de acuerdo con las condiciones climáticas locales. Es prudente proponer otros arreglos de lagunas, luego comparar los resultados considerando la disponibilidad del terreno, recursos económicos y las normas de calidad aplicables.

  2. Delivery of Services of Day Care Workers In Sta. Maria, Laguna

    Directory of Open Access Journals (Sweden)

    ROLANDO R. CRUZADA, JR.

    2014-02-01

    Full Text Available This study focused on the determination of the delivery of services of day care workers in the municipality of Sta. Maria, Province of Laguna during the first semester of school year 2012-2013. Descriptive research was used in this study. Among the key findings were that Day Care Workers with respect to interactional relationship accomplished the functions with outstanding adequacy such as constantly giving feedback and praises on the performance of children, along with workers and parents coordination and cooperation, with verbal interpretation of Always Observe. In terms of instructional quality both group of respondents perceived that day care workers in-charge had adequate abilities and competencies concerning their education and trainings in connection with teaching small children with verbal interpretation of Always Observe. The parents had confidence to the day care workers in-charge of their children aside from regularly consulting the day care workers about their children’s progress with verbal interpretation of Always Observe. There were only 871 households who availed of the services of day care centers in which 27 workers were employed and each of them assigned to handle an average of 33 children. Notable along with other findings was the day care workers and parents had the same perception as to the extent of services provided by the Day Care Center with respect to interactional relationship, instructional quality and parental participation. Subsequently the study ensued with these five factual remarks: Children’s interactions with parents in the centers were the direct mechanisms through which children learn. The educational qualification and the capability of the day care workers to handle small children were the primary essentials in children’s learning. Parents’ participation in the day care centers premises brought harmonious relationship between the Day Care Workers and children as well. The capacity of day care worker

  3. Instrumentos de molienda: evidencias del procesamiento de recursos vegetales en la laguna de Castillos (Rocha, Uruguay

    Directory of Open Access Journals (Sweden)

    Irina Capdepont

    2005-12-01

    Full Text Available Se presentan los resultados obtenidos del estudio de instrumentos de molienda recuperados en la Excavación I del montículo A del sitio Guardia del Monte -laguna de Castillos- Uruguay. Para realizar el trabajo se procedió a la caracterización de los instrumentos de molienda mediante el relevamiento de los atributos físicos y de las características funcionales. Para esto último se aplicó la Técnica de Extracción e Identificación de Partículas Biosilíceas, con el objetivo de realizar correlaciones entre instrumentos particulares y tipos de recursos vegetales específicos. Asimismo, se emplearon fuentes escritas profundizando en los aspectos relacionados con la molienda y uso de recursos vegetales. Los resultados obtenidos permitieron identificar el procesamiento de vegetales con aplicaciones alimenticias (preparación de harinas, bebidas fermentadas, etc. y tecnológicas (textilería, cordelería, cestería, entre los que se identificaron recursos silvestres y cultivados o manejados. Algunos instrumentos presentaron evidencias de procesamiento de recursos alimenticios, otros de recursos tecnológicos y finalmente otros con indicios de multifuncionalidad. Asimismo, se constató una cierta correlación entre algunos de los atributos físicos de los instrumentos y la funcionalidad atribuida a partir de los vegetales identificados y los usos referidos en las fuentes etnográficas.This paper presents the results from studies performed on milling stone tools recovered at Excavation I, Mound A from Guardia del Monte Site, Castillos lagoon, Uruguay. Physical attributes and functional features were used for the characterization of grinding artefacts. To this end opal phytoliths were extracted and analyzed in order to correlate different kinds of artefacts with specific vegetable resources. Written sources were used additionally to reach a deeper understanding of other aspects related to grinding activities and use of vegetable resources. The

  4. Magnetotelluric Studies of the Laguna del Maule Volcanic Field, Central Chile

    Science.gov (United States)

    Cordell, D. R.; Unsworth, M. J.; Diaz, D.; Pavez, M.; Blanco, B.

    2015-12-01

    Geodetic data has shown that the surface of the Laguna del Maule (LdM) volcanic field in central Chile has been moving upwards at rates >20 cm/yr since 2007 over a 200 km2 area. It has been hypothesized that this ground deformation is due to the inflation of a magma body at ~5 km depth beneath the lake (2.8 km b.s.l.). This magma body is a likely source for the large number of rhyolitic eruptions at this location over the last 25 ka. A dense broadband magnetotelluric (MT) array was collected from 2009 to 2015 and included data from a geothermal exploration project. MT phase tensor analysis indicates that the resistivity structure of the region is largely three-dimensional for signals with periods longer than 1 s, which corresponds to depths >5 km. The MT data were inverted using the ModEM inversion algorithm to produce a three-dimensional electrical resistivity model which included topography. Four primary features were identified in the model: 1) A north-south striking, 10 km by 5 km, low-resistivity zone (inflation centre at a depth of ~5 km (2.8 km b.s.l.) is interpreted as a zone of partial melt which may be supplying material via conduits to account for the observed ground deformation; 2) A shallow low-resistivity feature ~400 m beneath the lake surface (1.8 km a.s.l.) and spatially coincident with the inflation centre is interpreted to be a zone of hydrothermal alteration; 3) A thin, low-resistivity feature to the west of LdM at a depth of ~250 m (2.2 km a.s.l.) is interpreted to be the clay cap of a potential geothermal prospect; 4) A large, low-resistivity zone beneath the San Pedro-Tatara Volcanic Complex to the west of LdM at a depth of ~10 km (8 km b.s.l.) is interpreted to be a zone of partial melt. Further MT data collection is planned for 2016 which will expand the current grid of MT stations to better constrain the lateral extent of the observed features and give greater insight into the dynamics of this restless magma system.

  5. O jornal A Escola e a construção da escola moderna e republicana (Laguna, década de 1910 - The newspaper A Escola and the construction of modern and republican school (Laguna, decade of 1910

    Directory of Open Access Journals (Sweden)

    Gladys Mary Ghizoni Teive

    2013-04-01

    Full Text Available O presente estudo analisa dois exemplares do jornal A Escola, veiculado no Grupo Escolar Jerônimo Coelho, de Laguna, Sul de Santa Catarina, em 1916. O que este jornalzinho teria a ver com aqueles que anos mais tarde foram popularizados por Decroly e Freinet e incorporados às escolas primárias brasileiras como parte das associações auxiliares da escola? Esta questão constituiu-se no fio condutor desta reflexão histórica, buscando indícios que contribuam para a discussão acerca do ensino ativo, carro-chefe da pedagogia moderna, e da escola ativa, principal bandeira da escola nova. Para tanto, analisa principais temas pautados pela gazeta A Escola quais sejam: o patriotismo republicano e a civilidade burguesa.Palavras-chave: jornal escolar, pedagogia moderna, grupo escolar. THE NEWSPAPER A ESCOLA AND THE CONSTRUCTION OF MODERN AND REPUBLICAN SCHOOL (LAGUNA, DECADE OF 1910AbstractThis study examines two copies of the newspaper The School, published by the School Group Jerônimo Coelho, Laguna, south of Santa Catarina in 1916. What would this newspaper have to do with those that years later were popularized by Decroly and Freinet and incorporated to Brazilian primary schools as part of the auxiliary school associations? This question was the thread of this historical reflection, seeking clues that would contribute to the discussion of active teaching, flagship of Modern Pedagogy, and active school, main feature of progressive education. Therefore, it analyzes the main themes debated by the newspaper The School such as: republican patriotism and bourgeois civility.Key-words: school newspaper, modern pedagogy, school group. EL PERIÓDICO A ESCOLA Y LA CONSTRUCCIÓN DE LA ESCUELA MODERNA Y REPUBLICANA (LAGUNA, DÉCADA DE 1910ResumenEl presente estudio analiza dos ejemplares del Periódico La Escuela, vehiculado en el Grupo Escolar Jerônimo Coelho, de Laguna, sur de Santa Catarina, en 1916. ¿Este periodiquito qué tendría que ver con

  6. La Incidencia de la Pendiente en la Distribución de las Morfologías de las Lagunas sobre Lomadas Arenosas (Corrientes, Argentina

    Directory of Open Access Journals (Sweden)

    Félix Ignacio Contreras

    2017-01-01

    Full Text Available En la provincia de Corrientes, el río Paraná ocupó sucesivamente diferentes tramos de su abanico aluvial, formando lomadas arenosas. En la actualidad, contiene un gran número de lagunas descriptas como pequeñas y circulares, teniendo en cuenta una descripción cualitativa obtenida de fotografías aéreas e imágenes satelitales. Sin embargo, hasta el momento los estudios acerca de la distribución, tamaño, características morfométricas y funcionalidades de las lagunas solo se limitaban a estudios de casos particulares. Por tal motivo, surgió la necesidad de profundizar los conocimientos de estos cuerpos de agua en su totalidad, a fin de lograr información más integral de la región que las contiene. Los resultados de este trabajo permitieron conocer la distribución de 38926 lagunas, con una densidad de 3 lagunas por Km2 , que representan el 20% de la densidad lacustre del paisaje. A su vez, predomina la forma circular (72% y las restantes varían en subcirculares y triangulares. En cuanto a la distribución de las formas sobre el paisaje de lomadas arenosas se pudo observar que existe un gradiente en dirección Este-Oeste, donde la concentración de formas más complejas aumenta hacia el Este y las formas simples y circulares aumentan hacia el Oeste. Esta situación se relaciona directamente la con topografía de las lomadas arenosas con un gradiente que va en la misma dirección. Mayores diferencias topográficas permiten una mayor interconexión de lagunas y en consecuencia formas complejas, mientras que por el contrario, relieves más planos hacia el Oeste contribuye a la segmentación de lagunas. Como resultado del análisis estadístico de las variables morfométricas de las lagunas en función de la topografía de las lomadas arenosas, ha posibilitado clasificar al mega abanico aluvial del río Paraná en diferentes tramos.

  7. Análisis preliminares de los materiales líticos provenientes de la Laguna Blanca Chica (Olavarría, Buenos Aires

    Directory of Open Access Journals (Sweden)

    Pablo G. Messineo

    2004-12-01

    Full Text Available En este trabajo se presentan los resultados preliminares sobre el estudio de los materiales líticos recuperado en la Laguna Blanca Chica (Partido de Olavarría, Provincia de Buenos Aires. El objetivo principal es conocer las estrategias relacionadas al aprovisionamiento y explotación de las materias primas presentes, como los procesos tecnológicos utilizados sobre las mismas. Los resultados obtenidos indican que la ftanita (55,58% y la cuarcita (43,23% fueron las materias primas más utilizadas. Los instrumentos (formales e informales presentan mayores frecuencias de ftanita. Los altos porcentajes de esta materia prima en la laguna se asemejan a otros sitios del área (e.g., Laguna La Barrancosa 2, Arroyo Tapalqué 1, lo cual puede deberse a su alta disponibilidad y excelente calidad para la talla. Por otro lado, se observa una gran variabilidad entre las rocas cuarcíticas, proponiéndose la explotación de distintas formaciones geológicas.In this paper we report some preliminary results of the study of lithic material recovered from Laguna Blanca Chica, Olavarría district, Buenos Aires Province. The main aim of the study is to gain knowledge of aspects related to the acquisition of, and technological process involved in, raw material exploitation. The results obtained show that more than 50% of the principal lithic resource used consisted of chert. Formal and informal artefacts were also made using mainly chert as the raw material. The high frequency of this raw material in the lagoon is similar to other sites in the area (e.g., Laguna La Barrancosa 2, Arroyo Tapalqué 1, and may be due to its high natural availability and good chipping quality. Even so, a great variability of quartzite rocks was observed, showing that different geological formations were exploited.

  8. Availability of ground water in parts of the Acoma and Laguna Indian Reservations, New Mexico

    Science.gov (United States)

    Dinwiddie, George A.; Motts, Ward Sundt

    1964-01-01

    The need for additional water has increased in recent years on the Acoma and Laguna Indian Reservations in west-central New Mexico because the population and per capita use of water have increased; the tribes also desire water for light industry, for more modern schools, and to increase their irrigation program. Many wells have been drilled in the area, but most have been disappointing because of small yields and poor chemical quality of the water. The topography in the Acoma and Laguna Indian Reservations is controlled primarily by the regional and local dip of alternating beds of sandstone and shale and by the igneous complex of Mount Taylor. The entrenched alluvial valley along the Rio San Jose, which traverses the area, ranges in width from about 0.4 mile to about 2 miles. The climate is characterized by scant rainfall, which occurs mainly in summer, low relative humidity, and large daily fluctuations of temperature. Most of the surface water enters the area through the Rio San Jose. The average annual streamflow past the gaging station Rio San Jose near Grants, N. Mex. is about 4,000 acre-feet. Tributaries to the Rio San Jose within the area probably contribute about 1,000 acre-feet per year. At the present time, most of the surface water is used for irrigation. Ground water is obtained from consolidated sedimentary rocks that range in age from Triassic to Cretaceous, and from unconsolidated alluvium of Quaternary age. The principal aquifers are the Dakota Sandstone, the Tres Hermanos Sandstone Member of the Mancos Shale, and the alluvium. The Dakota Sandstone yields 5 to 50 gpm (gallons per minute) of water to domestic and stock wells. The Tres Hermanos sandstone Member generally yields 5 to 20 gpm of water to domestic and stock wells. Locally, beds of sandstone in the Chinle and Morrison Formations, the Entrada Sandstone, and the Bluff Sandstone also yield small supplies of water to domestic and stock wells. The alluvium yields from 2 gpm to as much as 150

  9. A High-Resolution Reconstruction of Late Holocene Environmental Change from Laguna Ek'Naab, Northern Holmul Region, Peten, Guatemala

    Science.gov (United States)

    Anderson, L.; Wahl, D.; Estrada-Belli, F.

    2015-12-01

    Widespread demographic shifts in the southern Maya lowlands at the end of the Classic period have been attributed to environmental change caused by human activity and/or climate variability. Fire was essential to landscape modification and was a primary agent of environmental change associated with prehispanic land use. While several studies have provided insight into the dynamic relationship between natural and anthropogenic drivers of change, defining the specific interplay between natural environmental change, human modification of the environment, and cultural response to changes remains a persistent challenge. Here we present the results of a multi-proxy study that reconstructs fire history, agricultural land use, and environmental change during and after Pre-Columbian Maya settlement. Results are interpreted in the context of settlement history as inferred from archaeological mapping around the study site. Our findings suggest landscape disturbance, as indicated by erosion, local burning, and nearby maize agriculture, was at its peak during the Early Classic period. This disturbance was likely due to large-scale settlement at the nearby site of Witzna'. All proxies indicate a slow decline in disturbance into the Late Classic period, beginning around 1300 cal yr BP. Cival and Chanchich, two proximal site centers to the south of Laguna Ek'Naab, supported their largest populations during the Late Preclassic and Late Classic, with little or no settlement during the Early Classic. The data from Laguna Ek'Naab suggests that Witzna' may have been an important center during the Early Classic. Whether the decreasing environmental degradation after 1240 cal yr BP is do to a decline in local population or changing land use strategies is not discernable based on the data thus far. However, the near complete absence of burning and continued decrease in erosion from 1240-1090 cal yr BP suggests little anthropogenic activity in the area. Burning resumes in the watershed

  10. Participation of the ININ in the activities of radioactive waste management of the Laguna Verde Central; Participacion del ININ en las actividades de gestion de desechos radiactivos de la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Medrano L, M.; Rodriguez C, C.; Linares R, D. [ININ, Gerencia Subsede Sureste (Mexico); Ramirez G, R.; Zarate M, N. [Central Laguna Verde, CFE (Mexico)]. e-mail: maam@nuclear.inin.mx

    2006-07-01

    From the beginning of the operation of the Laguna Verde Central (CLV) the National Institute of Nuclear Research (ININ) has come supporting the CLV in the activities of administration of the humid and dry radioactive waste generated by the operation of the two units of the CLV, from the elaboration of procedures to the temporary storage in site, the implementation of a program of minimization and segregation of dry solid wastes, until the classification of the lots of humid waste and bulk dry wastes. In this work the description of the management activities of radioactive wastes carried out by the ININ in the facilities of the CLV to the date is presented, as well as some actions that they are had drifted in the future near, among those that it stands out the determination of the total alpha activity in humid samples by means of scintillation analysis. (Author)

  11. Estimation of requirements of eolic energy equivalent to the electric generation of the Laguna Verde nuclear power plant; Estimacion de requerimientos de energia eolica equivalente a la generacion electrica de la Central Nucleoelectrica de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Garcia V, M.A.; Hernandez M, I.A. [Facultad de Ingenieria, Division de Ingenieria Electrica, UNAM, 04510 Mexico D.F. (Mexico)]. E-mail: maiki27@yahoo.com; Martin del Campo M, C. [Facultad de Ingenieria, Laboratorio de Analisis en Ingenieria de Reactores Nucleares, UNAM, Paseo Cuauhnahuac 8532, 62550 Jiutepec, Morelos (Mexico)

    2004-07-01

    The advantages are presented that have the nuclear and eolic energy as for their low environmental impact and to the human health. An exercise is presented in the one that is supposed that the electric power generated by the Laguna Verde Nuclear Power plant (CNLV), with capacity of 1365 M W, it should be produced by eolic energy when in the years 2020 and 2025 the units 1 and 2 of the CNLV reach its useful life and be moved away. It is calculated the number of aero generators that would produce the electric power average yearly of the CNLV, that which is equal to install eolic parks with capacity of 2758 M W, without considering that it will also be invested in systems of back generation to produce electricity when the aero generators stops for lack of wind. (Author)

  12. Improvements to the RELAP/SCDAPSIM of Laguna Verde model for the analysis of transients and accidents; Mejoras al modelo de Laguna Verde de RELAP/SCDAPSIM para el analisis de transitorios y accidentes

    Energy Technology Data Exchange (ETDEWEB)

    Amador G, R.; Castillo D, R.; Ortiz V, J.; Araiza M, E.; Martinez C, E., E-mail: rogelio.castillo@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2016-09-15

    This work presents the improvements to the integral model of the nuclear power plant of Laguna Verde for the RELAP/SCDAPSIM code, for the simulation of transients and severe accidents. The model includes a new detailed geometry of the steam lines, as well as improvements in the performance of the emergency systems. A primary containment model has also been created, which will be used to analyze the effect of safety valve and relief valve discharges to the wet well suppression pool and the effect of the rupture of a recirculation loop on the dry well. The simulations performed with the new model show that the changes made improve the prediction of the phenomenology involved during transients and accidents. (Author)

  13. Out of operation in simultaneous way of the two reactors of nucleoelectric central of Laguna Verde(Mexico); Fuera de operacion, de maneira simultanea, los dos reactores de la central nucleoelectrica de Laguna Verde (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Mar, Bernardo Salas, E-mail: salasmarb@yahoo.com.mx [Universidad Nacional Autonoma de Mexico, D.F. (Mexico). Facultad de Ciencias. Departamento de Fisica

    2013-11-01

    The two nuclear reactors that Mexico has in the Laguna Verde Nuclear Power Plant, were out of operation simultaneously in September 2012. First it was reported that one of the reactors had problems with the diesel generator, while the other had problems with the nuclear fuel reloading. The day after it was reported a problem related to sediment in the Obra de Toma, place the plant feeds seawater to cool the condenser the depth to which it must operate is 6 meters, with the current level of 1.5 meters, causing a lack of cooling water. Finally it was reported the cause of the suspension of operations, the cracks in jet pumps in both reactors. It is described a brief analysis of these opinions. The reactors are of cooling water of General Electric (BWR-5) and generate 1640 MWe each one.

  14. Applications of the monitor of loose parts in the cycle 6 of the Laguna Verde Unit 2 power plant; Aplicaciones del monitor de partes sueltas en el ciclo 6 de la Unidad 2 de la central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Calleros, G.; Mendez, A.; Gomez, R.A. [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Veracruz (Mexico); Castillo, R.; Bravo, J.M. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail: gcm9acpp@cfe.gob.mx

    2004-07-01

    The monitor of loose parts (Loose Parts Monitoring System) installed in the Unit 2 of the Laguna Verde Central is a tool to detect strange objects or parts loose in the system of refrigeration of the reactor that could be impacted in the walls of the recirculation knots or in the internal of the reactor. In this work two applications are shown carried out with the Monitor of Loose Parts, determining the characteristics of the stable nominal conditions, those which when changing, they are used to diagnose during the Cycle 6 of the Unit 2, failures in the components of the the recirculation circuits or to identify mechanical vibrations of the recirculation knots induced by a flow of recirculation bistable associated to operative conditions of the reactor. (Author)

  15. Turbine model for the Laguna Verde nucleo electric central based in the RELAP code; Modelo de turbina para la Central nucleoelectrica de Laguna Verde basado en el codigo RELAP

    Energy Technology Data Exchange (ETDEWEB)

    Cortes M, F.S.; Ramos P, J.C.; Salazar S, E.; Chavez M, C. [Facultad de Ingenieria, Division de Estudios de Posgrado, Grupo de Ingenieria Nuclear, UNAM (Mexico)]. e-mail: cchavez2@cableonline.com.mx

    2003-07-01

    The Nuclear Power stations as Laguna Verde occupy at the present time a place every time but important as non pollutant alternative, economic and trusty to generate electricity. It is for it that the Group of Nuclear Engineering of the Engineering Faculty (GrlNFI) of the National Autonomous University of Mexico (UNAM) it develops investigation projects applied to Nuclear Centrals. One of the projects in process is the development of a Classroom simulator, which it can configures to consent to diverse models of nuclear systems with training purposes in normal operation, or, to consent to specialized nuclear codes for the analysis of transitory events and have a severe accident. This work describes the development, implementation and it proves of a simplified model of the Main turbine to be integrated to the group of models of the Classroom simulator. It is part of the current effort of GrlNFI guided to obtain a representation of all the dynamic models necessary to simulate the Plant Balance of the Laguna Verde Central. It is included the development of the unfolding graphic which represent the modeling of the Main turbine, and of the control interface that allows the user to manipulate in simple way, direct and interactive this device during the training or the analysis. With this work it is wanted to contribute to the training of new technicians and to support the operation personnel of the Centrals. Also, the developed infrastructure is guided to contribute in the design and analysis of new Nuclear Power stations with the contribution of new computational tools for the visualization, simulation and process control. (Author)

  16. Development of an interactive model of the Laguna Verde nuclear power plant based on the RELAP/SCDAP code; Desarrollo del modelo interactivo de la central nucleoelectrica de Laguna Verde basado en el codigo RELAP/SCDAP

    Energy Technology Data Exchange (ETDEWEB)

    Salazar C, J.H.; Ramos P, J.C.; Salazar S, E.; Chavez M, C. [LAIRN, FI-UNAM, DEPFI Campus Morelos, Jiutepec, Morelos (Mexico)]. e-mail: cchavez2@cableonline.com.mx

    2003-07-01

    The present work describes the development of an interactive model of the Nuclear power plant of Laguna Verde (CNLV) based on the RELAP/SCDAP nuclear code, and it incorporation to a classroom simulator. The functional prototype it allows to make evaluations for operational transients and postulates accidents, with capacitation purposes, training, analysis and design. It emphasizes on the methodology used to establish the inter activity. Such methodology, is based on a modular structure in the one that multiple processes can be executed in an independent way and where the generated information is stored in segments of shared memory (characteristic that allows the UNIX operating system) and sent to the different processes by means of communication routines developed in C programming language. The utility of the system is demonstrated by means of the use of interactive display graphics (mimic diagrams, pictorials and tendency graphics) for the simultaneous dynamic visualization of the variables more significant that involve to the pattern of a transitory event type (for example failure of the controller of feeding water in a BWR reactor). Near with the interactive module, it was developed a model of the reactor of the CNLV for the code of better estimation RELAP/SCDAP. Finally the evaluation of the model is described, where it is interpreted in general form the behavior of those main variables that describe the stationary state, corroborating that follow the same tendency that those reported in the FSAR (Final Safety Analysis Report) of the Laguna Verde plant. The obtained results allow to conclude that the made development was satisfactory and that it presents enormous advantages regarding the capacity and time of analysis when using tools of visualization in real time of execution. (Author)

  17. Analysis of internal events for the Unit 1 of the Laguna Verde nuclear power station; Analisis de eventos internos para la Unidad 1 de la Central Nucleolelectrica de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Huerta B, A.; Aguilar T, O.; Nunez C, A.; Lopez M, R. [Comision Nacional de Seguridad Nuclear y Salvaguardias, 03000 Mexico D.F. (Mexico)

    1993-07-01

    This volume presents the results of the starter event analysis and the event tree analysis for the Unit 1 of the Laguna Verde nuclear power station. The starter event analysis includes the identification of all those internal events which cause a disturbance to the normal operation of the power station and require mitigation. Those called external events stay beyond the reach of this study. For the analysis of the Laguna Verde power station eight transient categories were identified, three categories of loss of coolant accidents (LOCA) inside the container, a LOCA out of the primary container, as well as the vessel break. The event trees analysis involves the development of the possible accident sequences for each category of starter events. Events trees by systems for the different types of LOCA and for all the transients were constructed. It was constructed the event tree for the total loss of alternating current, which represents an extension of the event tree for the loss of external power transient. Also the event tree by systems for the anticipated transients without scram was developed (ATWS). The events trees for the accident sequences includes the sequences evaluation with vulnerable nucleus, that is to say those sequences in which it is had an adequate cooling of nucleus but the remoting systems of residual heat had failed. In order to model adequately the previous, headings were added to the event tree for developing the sequences until the point where be solved the nucleus state. This process includes: the determination of the failure pressure of the primary container, the evaluation of the environment generated in the reactor building as result of the container failure or cracked of itself, the determination of the localization of the components in the reactor building and the construction of boolean expressions to estimate the failure of the subordinated components to an severe environment. (Author)

  18. Palinology and stratigraphic sequences of the well ELS-1, Laguna Salada, B.C., Mexico; Palinologia y secuencias estratigraficas del pozo ELS-1, Laguna Salada, B.C., Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Helenes Escamilla, Javier [CICESE, Ensenada, B.C. (Mexico)

    1999-04-01

    Palinological analysis of 16 samples from the well ELS-1 in Laguna Salada, allows recognition of environmental changes in the drilled section. No age assignments are made because of the low diversity of the palinological assemblages recovered. These assemblages include species with ages from Campanian to Pleistocene. The cretaceous forms indicate reworking from a cretaceous unit within the Colorado river drainage basin. Integration of the palinological, lithological and well log data permit the recognition of three main cycles. The lower one is regressive and contains mostly fluvial to deltaic shallow marine sediments. The intermediate cycle is transgressive-regressive, contains the maximum flooding surface of the section studied and represents an interval of strong tectonic movements with well developed marine transgressions. The upper cycle is also transgressive-regressive, with lagoon and distal alluvial fan deposits. [Spanish] El analisis palinologico de 16 muestras del pozo: ELS-1 del proyecto geotermico de Laguna Salada permite reconocer cambios ambientales en la seccion perforada. La baja diversidad de los conjuntos palinologicos recuperados impide determinar edades. Se observan especies indicadoras de edades desde Campaniese hasta Pleistoceno. Las formas cretacicas indican retrabajo de alguna unidad cretacica dentro de la cuenca del rio Colorado. La integracion de datos palinologicos, litologicos y de registros geofisicos, permite reconocer tres ciclos principales. El ciclo inferior es regresivo y contiene principalmente sedimentos fluviales a deltaicos de niveles bajos del mar. El ciclo intermedio, es transgresivo-regresivo, contiene la superficie de inundacion maxima de toda la seccion estudiada y representa una etapa de movimientos tectonicos fuertes con transgresiones marinas bien desarrolladas. El ciclo superior tambien es transgresivo-regresivo, con depositos lagunares y de abanicos aluviales distales.

  19. Composición por especies y tallas de los peces en la laguna Barra de Navidad, Pacífico central mexicano

    Directory of Open Access Journals (Sweden)

    Gaspar González-Sansón

    2014-03-01

    Full Text Available Las lagunas costeras son consideradas áreas de crianza importantes para muchas especies de peces costeros. La laguna costera Barra de Navidad (3.76km² es importante para la economía local y soporta un desarrollo turístico y pesquerías artesanales. Sin embargo, el rol de esta laguna en la dinámica de las poblaciones de peces costeros es poco conocido. Los objetivos de la investigación fueron: caracterizar el agua de la laguna y las condiciones climáticas relacionadas, elaborar el elenco sistemático de la ictiofauna y estimar la proporción de juveniles en el total de individuos capturados de las especies más abundantes. Las operaciones de recolecta de peces se realizaron entre marzo 2011 y febrero 2012. Se utilizaron varios artes de pesca diferentes que incluyeron atarraya, chinchorro playero y redes de agalla con cuatro tamaños de malla diferentes. Se midieron las variables físicas y químicas en épocas de lluvias y de secas. La laguna es euhalina (salinidad 30-40 ups la mayor parte del tiempo, aunque en determinados periodos cortos puede tener características mixopolihalinas (salinidad 18-30 ups. Las concentraciones de clorofila y nutrientes indican que la laguna está eutrofizada. La temperatura media del agua varió estacionalmente de 24.9°C (abril, pleamar a 31.4°C (octubre, bajamar. Se recolectaron en total 36 448 individuos, pertenecientes a 92 especies, de las cuales 31 tienen una relevancia ecológica con base en el número de individuos capturados. Las especies dominantes fueron: Anchoa spp. (44.6%, Diapterus peruvianus (10.5%, Eucinostomus currani (8.1%, Cetengraulis mysticetus (7.8%, Mugil curema (5.2% y Opisthonema libertate (4.5%. La laguna es un hábitat de juveniles importante para 22 de las 31 especies más abundantes. Estas incluyeron algunas especies de importancia comercial como los pargos (Lutjanus argentiventris, L. colorado y L. novemfasciatus, el robalo (Centropomus nigrescens y la lisa (Mugil curema. Otras

  20. La denuncia a través de la mujer: La casa de la laguna, de Rosario Ferré

    Directory of Open Access Journals (Sweden)

    Ana Molestina

    2015-08-01

    Full Text Available La historia puertorriqueña es una historia de imposiciones identitarias, choques culturales y ambivalencia desde la llegada de los españoles a la isla. En La casa de la laguna, Ferré analiza el pasado  y el presente de Puerto Rico. Crea una reconstrucción simbolizada en la historia de las familias Mendizábal-Monfort, en la cual Isabel Monfort, trata de descubrir las causas del fracaso de su matrimonio. En esta búsqueda y reflexión personal, se representan las versiones olvidadas o silenciadas de la historia puertorriqueña y de igual manera, da voz y vida a las mujeres marginadas o silenciadas.

  1. Las dependencias regionales de los asentamientos humanos localizados en el parque nacional “Lagunas de Chacahua”, Oaxaca

    Directory of Open Access Journals (Sweden)

    Marco Antonio Huerta García

    2000-01-01

    Full Text Available Este trabajo tiene como objetivo revelar la dinámica regional de los asentamientos humanos localizados en el parque nacional Lagunas de Chacahua". derivada de actividades de prioritaria necesidad poblacional. En una primera parte se presentan las principales posturas teórico-metodológicas asumidas en la investigación. En la segunda, se identifica una jerarquía de cuatro asentarnientos humanos de interés, presentes en el territorio, que permite apreciar la importancia relativa de éstos dentro del parque nacional. El contenido final se desarrolla sobre la base de la correlación espacial entre la jerarquía revelada y las dependencias regionales de funciones esenciales de los residentes locales, como la asistencia médica, el abasto alimentario y la comercialización de la producción pesquera.

  2. Diversidad florística asociada a las lagunas andinas Pomacocha y Habascocha, Junín, Perú

    Directory of Open Access Journals (Sweden)

    Mercedes Flores

    2013-05-01

    Full Text Available Se realizó un estudio de la diversidad florística de los alrededores de las lagunas Pomacocha y Habascocha (4350 - 4550 m de altitud, 11°45’-11°48’S y 75°12’-75°15’O, Provincia de Concepción, Junín, Perú. Se han registrado 29 familias, 64 géneros y 100 especies. Poaceae fue la familia con mayor diversidad específica (25%, seguida por Asteraceae (24% y Gentianaceae (6%. Se hace una comparación de la composición florística de la puna de Concepción con la de otras localidades de la puna del Perú.

  3. Tectonic forcing of shelf-ramp depositional architecture, Laguna Madre-Tuxpan Shelf, western Gulf of Mexico

    Science.gov (United States)

    Wawrzyniec, Tim F.; Ambrose, W.; Aranda-Garcia, M.; Romano, U. H.

    2004-07-01

    Analysis of seismic reflection data reveals the existence of a major listric fault that accommodates most of the Neogene extension of the Laguna Madre-Tuxpan shelf of the western Gulf of Mexico. The variation of related growth strata, the profile of the modern shelf-slope transition, the linear gradient of shelf extension (as well as basin accommodation) along the trace of the fault support a hypothesis that sediment loading along the northern part of the fault drives fault motion and influences sediment distribution along the southern end of the fault. In particular, where kinematic accommodation appears to outpace sediment supply, sedimentation is maximized along a shelf-ramp system and not the shelf-slope transition.

  4. Laguna del Maule magma feeding system and construction of a shallow silicic magma reservoir

    Science.gov (United States)

    Cáceres, Francisco; Castruccio, Ángelo; Parada, Miguel; Scheu, Bettina

    2017-04-01

    Laguna del Maule Volcanic Field is composed by at least 130 basaltic-to-rhyolitic eruptive vents that erupted more than 350 km3 of lavas and pyroclasts since Pleistocene in the Chilean Andes. It has captivated attention because of its current high accelerated uplift suggested to be formed by a growing shallow rhyolitic magma reservoir beneath the zone of deformation. Studying six Holocene post-glacial andesitic-to-rhyolitic lavas and one dome that partially overlap the ground-inflation zone, we determined the architecture and steps of construction of the magma feeding system that generated its post-glacial effusive volcanism. Further we suggest a possible origin for the rhyolitic magma that generated the ring of rhyolites encircling the lake and remain active causing the uplift. Mineral chemistry and textures suggest the same provenance of magma for the studied units, as well as complex magmatic history before eruptions. Similar temperatures, pressures, H2O and fO2 conditions for amphibole crystallisation in first stages indicate a common ˜17 km deep original reservoir that differentiated via in-situ crystallisation. The chemistry of the amphiboles present in all not-rhyolitic units shows trends that indicate a temperature domain on their crystallisation over other thermodynamic parameters such as pressure, water activity or chemistry of co-crystallising phases. All this supports a mush-like reservoir differentiating interstitial magma while crystallisation occurs. P-T conditions for amphibole crystallisation indicate that only amphiboles from rhyodacites show a non-adiabatic decompression that give rise to a polybaric and polythermal evolution trend from ˜450-200 MPa and ˜1030-900 ˚ C. In addition, unbuffered fO2 conditions were calculated for rhyodacite amphibole crystallisation upon cooling from melts with rather constant H2O contents. We propose that a large part of these rhyodacite amphiboles were formed during a non-adiabatic magma ascent similar to that

  5. La comunidad de peces de la Laguna de Términos: estructura actual comparada

    Directory of Open Access Journals (Sweden)

    Luis Amado Ayala-Pérez

    2003-09-01

    Full Text Available Se presentan los resultados de investigación sobre la ecología de la comunidad de peces de la Laguna de Términos. Se describe la estructura y se discute de manera comparada con la información publicada. Se realizaron 19 campañas mensuales de campo en 23 sitios de muestreo durante el periodo de septiembre de 1997 a marzo de 1999. Se identificaron 107 especies de peces que se agruparon en 76 géneros y 37 familias. Se capturaron 25588 organismos con un peso total de 601.5 kg. La abundancia de la comunidad en escala temporal osciló de 0.395 a 0.895 ind/m² ; 8.638 a 18.316 g/m² y 18.358 a 34.837 g/ind. La diversidad de la comunidad, estimada por el índice de Shannon y Weaver osciló entre 1.875 y 3.995. El valor de los índices de equitatividad y riqueza de especies presentaron una variación entre 0.519 y 0.993 y 4.94 y 7.88 respectivamente. Se identificaron 18 especies dominantes con base en el análisis de los valores de número de individuos, peso y porcentaje de aparición. La especie más importante tanto por su abundancia numérica como por su frecuencia de aparición es Arius melanopus que representa el 26.5% de la captura total seguida de Diapterus rhombeus con el 18.9%. También como especies dominantes cabe destacar la presencia de aquellas de interés pesquero tanto local como regional y son Bairdiella chrysura, B. ronchus, Archosargus rhomboidalis, Eugerres plumieri, Cynoscion arenarius y Chaetodipterus faberThe structure of the fish community in Terminos Lagoon, Campeche, is analyzed on the base the description of the abundance, distribution, length composition and identification of the dominant species. The results are discussed and compared with the published information. 437 trawl tows were made in 19 monthly collection in 23 sites between September 1997 to March 1999. A total of 25 588 individual with a total weight of 601.5 kg were grouped in 107 species, 76 gender and 37 families. The abundance of the fish community

  6. Laguna Verde: a 120% extended power up-rate project developed by Iberdrola

    Energy Technology Data Exchange (ETDEWEB)

    Merino Teillet, A.; Garcia-Serrano Tapia, J. L.; Ruiz Gutierrez, L. [Iberdrola Ingenieria y Construccion S.A Sociedad Unipersonal (Spain)

    2010-07-01

    The experience which this document wants to present, describes the work being developed by IBERDROLA Ingenieria y Construccion, for the Laguna Verde plant in Mexico, owned by the Federal Electricity Commission (CFE). This generation plant consists of two light boiling water type units (BWR) design by General Electric in the 80's. The objective of this project is to perform the modifications on the thermal cycle of the plant required by an Extended Power Up-rate, to achieve a safe and reliable operation of the plant at 120% of its original thermal power, whilst upgrading and renovating plant equipment and installations to achieve a license renewal from 40 to 60 years of operation The consortium formed in 97% by IBERDROLA Ingenieria y Construccion SAU and in 3% by ALSTOM Mexicana, S.A. de CV, was awarded the contract in an international bid, competing against General Electric and Siemens. The project began in March 2007 and is scheduled to finalize in December 2010. At this point the work carried out include modifications of the main condenser replacement, moisture separator reheaters (MSR's) and feedwater heaters no. 5 and 6 in the two units, therefore having executed two out of four scheduled outages. The scope, development and organization of this project, whose basic elements include the design, engineering, training, supply of equipment, dismantling, installation, testing, commissioning, treatment and delivery of radioactive waste generated during the project implementation to CFE, is aimed to ensure a safe and reliable operation of the plant under the new conditions of increased thermal power of the reactor, with a thermal cycle optimized so that the gross power of the generator increase from the current 686.7 MWe to a value of 817.1 MWe in both units. An Extended Power Up-rate means an opportunity to modernize equipments, to improve maintenance, to get a better plant knowledge and to motivate the employees facing a challenging project. This project

  7. Biología del pejerrey Odontesthes bonariensis (Pisces, Atherinopsidae de la laguna Los Charos (Córdoba, Argentina

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    Miguel Mancini

    2008-12-01

    Full Text Available El pejerrey Odontesthes bonariensis es la especie más importante de las pesquerías del centro de Argentina. Se estudio la captura por unidad de esfuerzo (CPUE, la condición corporal, el crecimiento y la alimentación de O. bonariensis de la laguna pampeana Los Charos (34º28´S, 64º23´W, 240 ha, ubicada en la provincia de Córdoba. Se realizaron cuatro muestreos estacionales en el periodo 2002-2003. Para la captura de peces se utilizaron redes de arrastre y enmalle. Se capturaron 2862 ejemplares de un rango de talla comprendido entre 38 y 380 mm de longitud estándar (LSt. La CPUE promedio fue de 74,3(±71,0kg/20 hs de tendido de red. La relación LSt-peso presentó diferencias significativas entre épocas del año (P< 0,01. Los índices de condición corporal estuvieron dentro de los límites de referencia de la especie. El crecimiento calculado fue: LSt(t=459,8*[1–exp(-0,3105*(t-0,175]. La relación LSt–Longitud total (LT fue: LT(mm=8,23+LSt*1,14 (n=283; R2=0,99. El zooplancton constituyó un ítem alimenticio secundario en los peces jóvenes. En los ejemplares de 3+ años de vida se observó un marcado canibalismo, situación que explicaría en parte su mejor condición corporal. La laguna Los Charos presenta una elevada producción de O. bonariensis.

  8. Recovery of floral and faunal communities after placement of dredged material on seagrasses in Laguna Madre, Texas

    Science.gov (United States)

    Sheridan, P.

    2004-03-01

    The objectives of this project were to determine how long alterations in habitat characteristics and use by fishery and forage organisms were detectable at dredged material placement sites in Laguna Madre, Texas. Water, sediment, seagrass, benthos, and nekton characteristics were measured and compared among newly deposited sediments and nearby and distant seagrasses each fall and spring over three years. Over this period, 75% of the estimated total surface area of the original deposits was either re-vegetated by seagrass or dispersed by winds and currents. Differences in water and sediment characteristics among habitat types were mostly detected early in the study. There were signs of steady seagrass re-colonization in the latter half of the study period, and mean seagrass coverage of deposits had reached 48% approximately three years after dredging. Clovergrass Halophila engelmannii was the initial colonist, but shoalgrass Halodule wrightii predominated after about one year. Densities of annelids and non-decapod crustaceans were generally significantly greater in close and distant seagrass habitats than in dredged material habitat, whereas densities of molluscs were not significantly related to habitat type. Nekton (fish and decapod) densities were almost always significantly greater in the two seagrass habitats than in dredged material deposits. Benthos and nekton communities in dredged material deposits were distinct from those in seagrass habitats. Recovery from dredged material placement was nearly complete for water column and sediment components after 1.5 to 3 years, but recovery of seagrasses, benthos, and nekton was predicted to take 4 to 8 years. The current 2 to 5 years dredging cycle virtually insures no time for ecosystem recovery before being disturbed again. The only way to ensure permanent protection of the high primary and secondary productivity of seagrass beds in Laguna Madre from acute and chronic effects of maintenance dredging, while ensuring

  9. Determinaciones de Parámetros de Diseño para Lagunas de Alta Velocidad con Residuales Pesqueros.

    Directory of Open Access Journals (Sweden)

    Teresita de Jesús Romero López

    2005-01-01

    Full Text Available Debido a la necesidad de conservar el medio ambiente circundante y muy especialmente las aguas interiores y costeras, se estudian diferentes sistemas de tratamiento de las aguas de desecho para su aplicación en instalaciones que carezcan de ellas. En el caso muy especial de la industria pesquera, donde solamente 14 establecimientos poseen tratamiento de los 42 activos hasta la fecha, se requiere del estudio y rápida puesta en marcha de alternativas que logren disminuir la carga contaminante hasta valores permisibles. Por tales motivos, además del estudio que se realizó a diferentes escalados para explorar y proponer un sistema de tratamiento por laguna de alta velocidad con microalgas del género Chlorella, se calcularon ecuaciones tanto empíricas como cinéticas a partir de los valores de Demanda Bioquímica de Oxígeno (DBO, con el objetivo de facilitar la predicción de la eficiencia del sistema en sí, así como su diseño. Para el cálculo de las ecuaciones empíricas se tuvieron en consideración las cargas orgánicas superficiales aplicadas y removidas (COa y COr y las cargas orgánicas volumétricas aplicadas y removidas (COva y COvr. Por otra parte, se comprobó que la ecuación de primer orden para un sistema en batch se ajusta al proceso depurador que ocurre en los mismos, siendo el valor promedio obtenido para la constante cinética del proceso 0,47 d¿1. Los resultados logrados en este estudio demuestran las grandes posibilidades que tienen las lagunas de alta velocidad para el tratamiento de las aguas residuales de la industria pesquera cubana, además de aportar una herramienta de gran valor para su diseño.

  10. Flora planctónica de laguna Lagartos, Quintana Roo Planktonic flora from Lagartos Lagoon, Quintana Roo

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    Viridiana Margarita Nava-Ruiz

    2012-09-01

    Full Text Available Se presenta una lista de la flora planctónica de la laguna Lagartos, basada en la observación de muestras superficiales obtenidas entre noviembre de 2007 a septiembre de 2008. Las muestras se recolectaron con una botella Van Dorn de 2 litros en la parte central de la laguna; se registraron 67 taxa: 28 Bacillariophyta, 22 Cyanoprokaryota, 7 Chlorophyta, 6 Dinoflagellata, 2 Euglenophyta y 2 Cryptophyta. Las cianofitas dominaron durante todo el periodo de estudio, con una contribución mayor al 80% de la abundancia total del fitoplancton. Son nuevos registros para México 13 especies: Chroococcus pulcherrimus, Coelosphaerium confertum, Cyanodyction iac, Phormidium pachydermaticum, Planktolyngbya contorta, Rhodomonas minuta, Amphidinium massartii, Ensiculifera cf. loeblichii, Heterocapsa cf. pseudotriquetra, Prorocentrum cassubicum, Licmophora normaniana, Fistulifera saprophila y Amphora richardiana. Todos los taxa listados se ilustran con microfotografías.The planktonic flora from Lagartos Lagoon, Quintana Roo, was examined based on the observation of samples collected from November 2007 to September 2008. The superficial samples were collected with a Van Dorn bottle of 2 L, in the core part of the lagoon. A total of 67 taxa were identified: 28 Bacillariophyta, 22 Cyanoprokaryota, 7 Chlorophyta, 6 Dinoflagellata, 2 Euglenophyta and 2 Cryptophyta. Nevertheless, the blue green algae dominated during all study period, with more of 80% to the total abundance of the phytoplankton. The species Chroococcus pulcherrimus, Coelosphaerium confertum, Cyanodyction iac, Phormidium pachydermaticum, Planktolyngbya contorta, Rhodomonas minuta, Amphidinium massartii, Ensiculifera cf. loeblichii, Heterocapsa cf. pseudotriquetra, Prorocentrum cassubicum, Licmophora normaniana, Fistulifera saprophila and Amphora richardiana were recorded for the first time in Mexico. All the taxa are illustrated with microphotographs.

  11. Variaciones morfológicas en Blackfordia virginica (Hydroidomedusae: Blackfordiidae en lagunas costeras de Chiapas, México

    Directory of Open Access Journals (Sweden)

    Carlos Álvarez Silva

    2003-06-01

    Full Text Available Blackfordia virginica es una hidromedusa importante en el zooplancton de lagunas costeras de México. Con el objeto de contribuir a su estudio se analizaron las variaciones morfológicas de esta especie en el sistema de lagunas costeras de Chiapas, México. Se estudiaron 503 ejemplares, sus tallas variaron de 6.1 a 9.9 mm de diámetro umbrelar; el número de tentáculos marginales varió de 86 a 125. Se reconocieron los sexos, 67.7% hembras y 30.2% machos. Solamente 31 medusas (26 hembras y cinco machos presentaron variaciones morfológicas, éstas fueron de 10 tipos distintos y afectaron principalmente el número y forma de conductos radiales y las gónadas. El tamaño de las medusas y el número de tentáculos reflejaron una correlación de 0.74.Blackfordia virginica is an important hydromedusae in the zooplankton of coastal lagoons at Mexico. In order to contribute to their study, morphological variations of these species were analyzed in the system of coastal lagoons of Chiapas, Mexico. A total of 503 jellyfish were studied their sizes varied from 6.1 to 9.9 mm of umbrelar diameter. The number of marginal tentacles varied from 86 to 125. A 67.7% females and 30.2% males were recognized. Only 31 jellyfish (26 females and five males presented morphological variations of ten different types and affected the number and form of the handles, radial channels and gonads. The size of the jellyfish and the number of tentacles reflected a correlation of 0.74.

  12. Atmospheric particles in the central coastal zone of the Gulf of Mexico, Laguna Verde area, Veracruz, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Salazar L, S.; Alvarez D, C.; Mendoza M, R.; Perez A, J. A. [Laboratorio de Ingenieria Ambiental, Central Nucleoelectrica Laguna Verde, Comision Federal de Electricidad, Veracruz (Mexico); Castellanos R, M. A; Gomez L, B. [Departamento de Quimica Analitica, Laboratorio de Rayos X, Facultad de Quimica, UNAM, Mexico, D.F. (Mexico)

    1997-01-01

    The results of mass concentration of atmospheric particles collected by low volume samplers in sixteen monitoring stations of the Environmental Radiological Monitoring Network from Laguna Verde Nucleoelectric Plant, in Mexico, from 1991 to 1993, are reported. The levels of the yearly average mass concentrations were in a range of 22.6 {mu}g/m{sup 3} {+-} 5.0 {mu}g/m{sup 3} to 107.8 {mu}g/m{sup 3} {+-} 3.7 {mu}g/m{sup 3}. This variability is explained through the location of the stations, anthropogenic and natural influences. There were no significant differences in the average concentration over time. Moreover, the preliminary results of the chemical composition obtained by X Ray Fluorescence analysis are presented. [Spanish] Se presentan los resultados de la concentracion por peso de las particulas atmosfericas recolectadas con muestreadores de bajos volumenes en 16 estaciones de la Red del Monitoreo Radiologico Ambiental de la Central Nucleoelectrica Laguna Verde, en Mexico, durante el periodo 1991 a 1993. Los niveles de concentracion por peso de las particulas varian en un rango de promedios anuales de 22.6 {mu}g/m{sup 3} {+-} 5.0 {mu}g/m{sup 3} a 107.8 {mu}g/m{sup 3} {+-} 3.7 {mu}g/m{sup 3}. Esta variabilidad es explicada por la ubicacion de las estaciones, y las influencias naturales y antropogenicas. No fue observada variabilidad significativa en las concentraciones promedio a lo largo del tiempo. Se presentan los primeros resultados de la caracterizacion quimica del aerosol costero obtenido por medio de Fluorescencia de Rayos X.

  13. Sr Isotopes and Migration of Prairie Mammoths (Mammuthus columbi) from Laguna de las Cruces, San Luis Potosi, Mexico

    Science.gov (United States)

    Solis-Pichardo, G.; Perez-Crespo, V.; Schaaf, P. E.; Arroyo-Cabrales, J.

    2011-12-01

    Asserting mobility of ancient humans is a major issue for anthropologists. For more than 25 years, Sr isotopes have been used as a resourceful tracer tool in this context. A comparison of the 87Sr/86Sr ratios found in tooth enamel and in bone is performed to determine if the human skeletal remains belonged to a local or a migrant. Sr in bone approximately reflects the isotopic composition of the geological region where the person lived before death; whereas the Sr isotopic system in tooth enamel is thought to remain as a closed system and thus conserves the isotope ratio acquired during childhood. Sr isotope ratios are obtained through the geologic substrate and its overlying soil, from where an individual got hold of food and water; these ratios are in turn incorporated into the dentition and skeleton during tissue formation. In previous studies from Teotihuacan, Mexico we have shown that a three-step leaching procedure on tooth enamel samples is important to assure that only the biogenic Sr isotope contribution is analyzed. The same Sr isotopic tools can function concerning ancient animal migration patterns. To determine or to discard the mobility of prairie mammoths (Mammuthus columbi) found at Laguna de las Cruces, San Luis Potosi, México the leaching procedure was applied on six molar samples from several fossil remains. The initial hypothesis was to use 87Sr/86Sr values to verify if the mammoth population was a mixture of individuals from various herds and further by comparing their Sr isotopic composition with that of plants and soils, to confirm their geographic origin. The dissimilar Sr results point to two distinct mammoth groups. The mammoth population from Laguna de Cruces was then not a family unit because it was composed by individuals originated from different localities. Only one individual was identified as local. Others could have walked as much as 100 km to find food and water sources.

  14. High-Resolution Paleosalinity Reconstruction From Laguna de la Leche, North Coastal Cuba, Using Sr, O, and C Isotopes

    Science.gov (United States)

    Peros, M. C.; Reinhardt, E. G.; Schwarcz, H. P.; Davis, A. M.

    2008-12-01

    Isotopes of Sr, O, and C were studied from a 227-cm long sediment core to develop a high-resolution paleosalinity record to investigate the paleohydrology of Laguna de la Leche, north coastal Cuba, during the Middle to Late Holocene. Palynological, plant macrofossil, foraminiferal, ostracode, gastropod, and charophyte data from predominantly euryhaline taxa, coupled with a radiocarbon-based chronology, indicate that the wetland evolved through four phases: (1) an oligohaline lake existed from 6200 to 4800 cal yr B.P.; (2) water level in the lake increased and the system freshened from 4800 to 4200 cal yr B.P.; (3) a mesohaline lagoon replaced the lake 4200 cal yr B.P.; and (4) mangroves enclosed the lagoon beginning 1700 cal yr B.P., forming a mesohaline lake. Isotopic ratios were measured on specimens of the euryhaline foraminifer Ammonia beccarii, although several measurements were also made on other calcareous microfossils in order to identify potential taphonomic and/or vital effects. The 87Sr/86Sr results show that the average salinity of Laguna de la Leche was 1.7 ppt during the early lake phase and 8 ppt during the lagoon phase - a change driven by relative sea level rise. The delta18O results do not record the salinity increase seen in the 87Sr/86Sr data, but instead indicate high evaporation from the lake surface. Variability in delta13C was controlled by plant productivity, episodic marine incursions, and vegetation community change. There is some evidence for seasonal effect and the lateral transport of microfossils prior to burial. Our results show that Sr isotopes, while often cited as a powerful paleosalinity tool, should be used in conjunction with other indicators when investigating paleosalinity trends; relying solely on any single isotopic or ecological indicator can lead to inaccurate results, especially in semi-enclosed and closed hydrological systems.

  15. Filogenética Molecular de Peces del Complejo Midas Cichlidae que habitan lagos y lagunas de Nicaragua, utilizando el gen COI

    Directory of Open Access Journals (Sweden)

    Lucía Páiz-Medina

    2012-12-01

    Full Text Available Las lagunas cratéricas de Nicaragua se consideran verdaderos "laboratorios" naturales de investigación debido a que son geológicamente jóvenes y por su pequeña dimensión, lo que permite el estudio de procesos evolutivos y de especiación. En estas lagunas se encuentran especies endémicas (familia Cichlidae que representan recursos valiosos para estudios de especiación, incluyendo la velocidad y fuerzas con las que el aislamiento geográfico, la selección natural y sexual provocan la diversificación fenotípica y, finalmente, la especiación misma. Los peces de la familia Cichlidae han sido objeto de mucha controversia debido a que morfológicamente es difícil diferenciarlos y se requieren de nuevas herramientas moleculares para descifrar las diferencias a nivel genético y entender mejor los procesos de especiación de este fascinante grupo de peces. En este estudio se utilizó el gen Citocromo Oxidasa I, COI, para determinar las relaciones filogenéticas entre los peces del Complejo presente en lagos y lagunas de Nicaragua. El COI ha sido propuesto como "código de barras" genético y como técnica ha sido estandarizada para animales. Este trabajo es parte de una investigación más grande que se enmarca en el Proyecto "DNA Barcoding de la biodiversidad nicaragüense" y se realiza en el Centro de Biología Molecular de la Universidad Centroamericana. Con este estudio se ha logrado determinar que: (1 el gen COI discrimina entre especies de diferentes lagunas, (2 las relaciones entre las especies Midas Cichlidae son complejas y es necesario más de un gen para obtener resultados concluyentes, (3 las especies fundadoras de las lagunas cratéricas provienen del lago de Nicaragua, (4 en las lagunas habitan más de una especie del Complejo Midas Cichlidae y (5 se infiere que la especiación simpátrica es el mecanismo evolutivo que ha conducido a la creación de estas especies, confirmando la hipótesis de otros autores y aportando nuevos

  16. Evaluación del proceso y la eficiencia de remoción de la materia orgánica en las lagunas de estabilización del municipio de La Ceja, Antioquia, Colombia

    Directory of Open Access Journals (Sweden)

    MEJÍA RUIZ ROBERTO

    2010-05-01

    Full Text Available En esta investigación, se estudió la condición ambiental y el funcionamiento de las lagunas de estabilización para el tratamiento de las aguas residuales del municipio de La Ceja, Antioquia. Este sistema ha presentado deficiencias en su operación, reflejadas en problemas organolépticos, hidráulicos y metabólicos. El sistema de lagunas del municipio de La Ceja está conformado por dos lagunas anaerobias y una laguna facultativa, que reciben las aguas residuales domésticas provenientes de un alcantarillado combinado. En los años 2003 y 2004, se realizaron mediciones de variables físicas, químicas y biológicas, incluyendo tres muestreos generales. El sistema funcionó deficientemente debido a problemas hidráulicos. La deficiencia del sistema estuvo acompañada de una baja remoción de nutrientes disueltos en la laguna facultativa asociada a un pobre desarrollo de la comunidad de microorganismos. El sistema presentó una remoción de carga orgánica del 75 %, relacionada principalmente con la sedimentación en las lagunas anaerobias.

  17. Modernization of the Electric Power Systems (transformers, rods and switches) in the Laguna Verde Nuclear Power Plant (Mexico); Modernizacion de los Sistemas Electricos de Potencia (Transformadores de Principales, Interruptor de Generacion, Barras de Fase Aislada) de la Central Nuclear de Laguna Verde (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Solarzano, J. J.; Gabaldon Martin, M. A.; Pallisa Nunez, J.; Florez Ordeonez, A.; Fernandez Corbeira, A.; Prieto Diez, I.

    2010-07-01

    Description of the changes made in the Electric Power Systems as a part of the power increase project in the Laguna Verde Nuclear Power Plant (Mexico). The main electrical changes to make, besides the turbo group, are the main generation transformers, the isolated rods and the generation switch.

  18. Components production and assemble of the irradiation capsule of the Surveillance Program of Materials of the nuclear power plant of Laguna Verde;Fabricacion de componentes y ensamble de la capsula de irradiacion del Programa de Vigilancia de Materiales de la central nuclear Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Medrano, A. [ININ, Departamento de Tecnologia de Materiales, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2009-07-01

    To predict the effects of the neutrons radiation and the thermal environment about the mechanical properties of the reactor vessel materials of the nuclear power plant of Laguna Verde, a surveillance program is implemented according to the outlines settled by Astm E185-02 -Standard practice for design of surveillance programs for light-water moderated nuclear power reactor vessels-. This program includes the installation of three irradiation capsules of similar materials to those of the reactor vessels, these samples are test tubes for mechanical practices of impact and tension. In the National Institute of Nuclear Research and due to the infrastructure as well as of the actual human resources of the Pilot Plant of Nuclear Fuel Assembles Production it was possible to realize the materials rebuilding extracted in 2005 of Unit 2 of nuclear power plant of Laguna Verde as well as the production, assemble and reassignment of the irradiation capsule made in 2006. At the present time the surveillance materials extracted in 2008 of Unit 1 of the nuclear power plant of Laguna Verde are reconstituting and the components are manufactured for the assembles of the irradiation capsule that will be reinstalled in the reactor vessel in 2010. The purpose of the present work is to describe the necessary components as well as its disposition during the assembles of the irradiation capsule for the surveillance program of the reactors vessel of the nuclear power plant of Laguna Verde. (Author)

  19. To report the obtained results in the simulation with the FCS-11 and Presto codes of the two first operation cycles of the Laguna Verde Unit 1 reactor; Reportar los resultados obtenidos en la simulacion con los codigos FCS-11 y PRESTO de los dos primeros ciclos de operacion del reactor Laguna Verde Unidad 1

    Energy Technology Data Exchange (ETDEWEB)

    Montes T, J.L.; Moran L, J.M.; Cortes C, C.C

    1990-08-15

    The objective of this work is to establish a preliminary methodology to carry out analysis of recharges for the reactor of the Laguna Verde U-1, by means of the evaluation of the state of the reactor core in its first two operation cycles using the FCS2 and Presto-B codes. (Author)

  20. Generation of the ECP database (ECP01.DAT) of the cycle 1 of the Unit 1 of Laguna Verde with burnt of 1377 MWD/MT; Generacion de la base ECP (ECP01.DAT) del ciclo 1 de la Unidad 1 de Laguna Verde con quemado de 1377 MWD/MT

    Energy Technology Data Exchange (ETDEWEB)

    Perusquia C, R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1992-10-15

    In order to carrying out a comparison among the results provided by the Program of Estimate of the ECP Critical Position and the Shutdown/Startup produced in the Cycle 1 of the Unit 1 of Laguna Verde, it was generated the base of the ECP program, following the outlines settled down in the Procedure 'Generation of ECP Database for Laguna Verde' (IT.SN/DFR-074). Next the data sheets filled when being generated the ECP01.DAT database with a burnt of 1377 MWD/MT are provided. In the report IT.SN/DFR-079 'Adjustment and Preliminary Evaluation of the Predictions of Criticity of the ECP Program with Reported Data of the Cycle 1 of the Unit 1 of Laguna Verde', the results of the comparison among those estimates of the ECP program using the ECP01.DAT database with the real data of the Cycle 1 of the Unit 1 of Laguna Verde are presented. (Author)

  1. Nuevas evidencias geofísicas de la existencia de una caldera cubierta en laguna Pozuelos: Puna norte New geophysical evidences of the presence of a buried caldera in Laguna Pozuelos: Northern Puna

    Directory of Open Access Journals (Sweden)

    Claudia B Prezzi

    2010-03-01

    Full Text Available En el extremo sur de la cuenca de laguna de Pozuelos aflora el complejo volcánico Pan de Azúcar. El mismo está integrado por varios centros eruptivos de composición dacítica y morfología dómica que poseen una edad de ~12 Ma. Interpretaciones previas de líneas sísmicas y un relevamiento magnetométrico detallado indicaron la presencia de cuerpos intrusivos no aflorantes. La determinación de la existencia de nuevos cuerpos intrusivos no aflorantes en la zona resulta de interés debido a que: 1 estos complejos volcánicos dacíticos están estrechamente asociados con mineralización de interés económico (forman parte del cinturón estañífero boliviano; y 2 la existencia de una caldera antigua (~ 12 Ma de grandes dimensiones, ahogada bajo la cubierta sedimentaria que rellena la depresión de Pozuelos, ha sido propuesta por distintos autores. Los complejos dómicos representarían las fases magmáticas finales de dicho sistema magmático caldérico. Con la finalidad de determinar la existencia de dicho sistema caldérico y/o de otros cuerpos intrusivos no aflorantes se llevaron a cabo nuevos relevamientos magnetométricos y gravimétricos terrestres detallados. El mapa magnetométrico obtenido presenta conspicuas anomalías positivas y negativas que dominan el sector sur de la cuenca, probablemente asociadas con la presencia de los domos dacíticos aflorantes. La anomalía residual de Bouguer presenta un patrón semicircular, mostrando sólo valores positivos. La curvatura de las señales magnetométricas y gravimétricas fue analizada y se utilizó la deconvolución de Euler para estimar las profundidades a las fuentes causantes de las anomalías detectadas. Los resultados obtenidos hasta el momento apoyan la hipótesis de la existencia de una gran caldera soterrada en la cuenca de Laguna Pozuelos. La identificación de un gran sistema caldérico mioceno medio contribuirá a una mejor comprensión de la evolución magmática de la Puna

  2. Determinación de Glifosato mediante inmunoensayo enzimático (ELISA en el Paisaje Protegido Laguna de Rocha y su entorno, Uruguay.

    Directory of Open Access Journals (Sweden)

    Daniela Nardo

    2015-12-01

    Full Text Available En el entorno de la Laguna de Rocha se ha visto incrementada la superficie dedicada a las actividades agrícolas con un mayor uso de plaguicidas, entre ellos el herbicida glifosato, usado en cultivos de soja principalmente. Mediante la utilización de técnicas de inmunoensayo enzimático (ELISA, se investigó la presencia de glifosato en la Laguna y algunos de sus afluentes en dos momentos específicos de tiempo. Se detectó glifosato en 27 de las 28 muestras estudiadas. Muestras positivas por ELISA fueron confirmadas por cromatografía iónica. El método ELISA demostró ser una herramienta de screening adecuada para determinar la presencia de glifosato en agua.

  3. Groundwater flow in a closed basin with a saline shallow lake in a volcanic area: Laguna Tuyajto, northern Chilean Altiplano of the Andes.

    Science.gov (United States)

    Herrera, Christian; Custodio, Emilio; Chong, Guillermo; Lambán, Luis Javier; Riquelme, Rodrigo; Wilke, Hans; Jódar, Jorge; Urrutia, Javier; Urqueta, Harry; Sarmiento, Alvaro; Gamboa, Carolina; Lictevout, Elisabeth

    2016-01-15

    Laguna Tuyajto is a small, shallow saline water lake in the Andean Altiplano of northern Chile. In the eastern side it is fed by springs that discharge groundwater of the nearby volcanic aquifers. The area is arid: rainfall does not exceed 200mm/year in the rainiest parts. The stable isotopic content of spring water shows that the recharge is originated mainly from winter rain, snow melt, and to a lesser extent from some short and intense sporadic rainfall events. Most of the spring water outflowing in the northern side of Laguna Tuyajto is recharged in the Tuyajto volcano. Most of the spring water in the eastern side and groundwater are recharged at higher elevations, in the rims of the nearby endorheic basins of Pampa Colorada and Pampa Las Tecas to the East. The presence of tritium in some deep wells in Pampa Colorada and Pampa Las Tecas indicates recent recharge. Gas emission in recent volcanoes increase the sulfate content of atmospheric deposition and this is reflected in local groundwater. The chemical composition and concentration of spring waters are the result of meteoric water evapo-concentration, water-rock interaction, and mainly the dissolution of old and buried evaporitic deposits. Groundwater flow is mostly shallow due to a low permeability ignimbrite layer of regional extent, which also hinders brine spreading below and around the lake. High deep temperatures near the recent Tuyajto volcano explain the high dissolved silica contents and the δ(18)O shift to heavier values found in some of the spring waters. Laguna Tuyajto is a terminal lake where salts cumulate, mostly halite, but some brine transfer to the Salar de Aguas Calientes-3 cannot be excluded. The hydrogeological behavior of Laguna Tuyajto constitutes a model to understand the functioning of many other similar basins in other areas in the Andean Altiplano.

  4. La principal colección de periódicos sobre Canarias: la hemeroteca de la Universidad de La Laguna

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    Dr. Javier González Antón

    1998-01-01

    Full Text Available Descripción de uno de los más importantes fondos hemerográficos del mundo sobre las Islas Canarias, las colecciones de periódicos y revistas, desde los manuscritos del siglo XVIII, los primeros impresos de 1785, hasta la serie completa de los actuales, conservados en la Hemeroteca de Canarias de la Universidad de La Laguna, con sus servicios y prestaciones.

  5. Modelización de la hidroquímica y sedimentoquímica de una laguna tipo playa (Cl- So2-4 Mg2+ - Na+: La Laguna Grande de Quero (Toledo

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    García del Cura, M. A.

    1991-08-01

    Full Text Available The «Laguna Grande de Quero», is a saline pond located on the aluvial system from the Cigüela and Riansares rivers. The pond's underground impermeable materials are claystone with gypsum from the Triassic ages. On the next reliefs appears gypsiferous-detrital and calcareous materials from the Tertiary ages. A model have been created for the evaporative process, correcting the saline effect bearing in mind the climatic parameters; the conclusions obtained are coherents with the experimental data, which have been obtained in two experimental pools placed for the evaporative- concentration processes chasing. The experimental precipitation sequence obtained was: calcite + gypsum → bloedite + thenardite → bloedite → epsomite + halite. This sequence has been studied about saits generated on the air-brine interface. Moreover coincide with the foreseeable theoric sequence, according to Valyashko diagrams. In the natural environment appears facies and paragenesis associations coherents with the experimental data. During the evaporative process to specific gravity and concentration evolution graphics show a stagnancy period, «plateau effect», that it seams to coincide with a differential heating from the depth waters. The explanation of this effect can be related with the salts dissolution previously formed.La Laguna Grande de Quero, se ubica en el sistema aluvial de los ríos Cigüela-Riansares. Los materiales del subsuelo impermeable de la laguna son lutitas con yeso del Trías. En los relieves próximos afloran materiales detrítico-yesíferos y calcáreos de edad Terciaria. Se ha establecido un modelo del proceso de evaporación, corrigiendo el efecto salino, y teniendo en cuenta los parámetros climáticos, obteniendo resultados coherentes con los datos obtenidos en las balsas experimentales instaladas para el seguimiento del proceso de evaporación-concentración de la salmuera. La secuencia de precipitación experimental

  6. Pesticide and PCB residues in the aquatic ecosystems of Laguna de Terminos, a protected area of the coast of Campeche, Mexico.

    Science.gov (United States)

    Carvalho, Fernando P; Villeneuve, Jean-Pierre; Cattini, C; Rendón, Jaime; Mota de Oliveira, J

    2009-02-01

    The coastal lagoon system of Laguna de Terminos, Campeche, Mexico, a natural reserve since 1994, was investigated for contamination by agricultural and industrial chemical residues. Water, sediment and biota samples were analyzed for a wide variety of organochlorine and organophosphorus compounds. Chlorpyrifos was detected in water in concentrations up to 72 pgL(-1) and, amongst organochlorine compounds, summation operator PCB were measured averaging 1177 pgL(-1) and summation operator DDT 279 pgL(-1). Residues of chlorinated compounds were present in sediments and in biota with summation operator DDT averaging 190 pg g(-1) and 5876 pg g(-1) in sediment and oysters, respectively. Results show that the more widespread contaminants in the Laguna were residues of chlorinated hydrocarbons, such as DDTs, PCBs, endosulfan, and lindane. Concentrations of residues were not at an alarming level and were even lower than reported for other costal lagoons of the region. Still there is a need to implement control measures on persistent and bioaccumulative compounds that may reach the aquatic system of Laguna de Terminos.

  7. Identification and dating of indigenous water storage reservoirs along the Rio San José at Laguna Pueblo, western New Mexico, USA

    Science.gov (United States)

    Huckleberry, Gary; Ferguson, T.J.; Rittenour, Tammy M.; Banet, Chris; Mahan, Shannon

    2016-01-01

    An investigation into indigenous water storage on the Rio San José in western New Mexico was conducted in support of efforts by the Pueblo of Laguna to adjudicate their water rights. Here we focus on stratigraphy and geochronology of two Native American-constructed reservoirs. One reservoir located near the community of Casa Blanca was formed by a ∼600 m (2000 feet) long stone masonry dam that impounded ∼1.6 × 106 m3 (∼1300 acre-feet) of stored water. Four optically stimulated luminescence (OSL) ages obtained on reservoir deposits indicate that the dam was constructed prior to AD 1825. The other reservoir is located adjacent to Old Laguna Pueblo and contains only a small remnant of its former earthen dam. The depth and distribution of reservoir deposits and a photogrammetric analyses of relict shorelines indicate a storage capacity of ∼6.5 × 106 m3 (∼5300 ac-ft). OSL ages from above and below the base of the reservoir indicate that the reservoir was constructed sometime after AD 1370 but before AD 1750. The results of our investigation are consistent with Laguna oral history and Spanish accounts demonstrating indigenous construction of significant water-storage reservoirs on the Rio San José prior to the late nineteenth century.

  8. The Laguna Verde Central by it results in maintenance and operation consolidates it position of world class enterprise; La central Laguna Verde por sus resultados en mantenimiento y operacion consolida su posicion de empresa de clase mundial

    Energy Technology Data Exchange (ETDEWEB)

    Rivera C, A. [CFE, Central Laguna Verde, Km. 42.5 Carretera Cardel- Nautla, Veracruz (Mexico)

    2008-07-01

    This work has the objective of showing the results of the Laguna VerdeCentral in the maintenance and the operation that in the short term the generation of electricity in Mexico by nuclear means is a viable option, in virtue of their positioning like Company of World Class, when winning March 25, 2008 the National Prize of Quality with the more high qualification in the history of this prize, same that allows us to be very optimistic in increasing the possibility to that the Nuclear Industry in Mexico grows. The focus of the comparative graphs, with official data of the Comision Federal de Electricidad (CFE), it is so that it is observed that the Laguna Verde Central is above those the other types of generation like they are the Coal power stations, Thermoelectric, Hydroelectric, likewise they can see that we are for up of the Independent Producers of Energy. The information of the electric power generation is presented by reactors nuclear at world level that is growing, in having 31 Generating Units in the construction process that favors the decisions making in the Government federal, likewise contributed data of the increment projected for 2016 in the country of 380,102 GWh that equivalent to 63% of growth, where it exists without place to doubts a good opportunity for the nucleoelectricity. The Investment Works Program of Public Sector (POISE), it shows the information that 6,178 Mwe will be installed settled of a Non-defined Technology in Mexico, information that specifies the opportunity to be a viable option, because the one Plant Factor, the Production of Electric power, and the Variable Cost of Production, the energy generation by nuclear means is the more competitiveness. Finally this work stood out the effort that communitary works are developed to benefit to the society and the environment to be one Viable option not only for their high performance, or competitive for those more low costs, but also to improve the public opinion with the sustainable

  9. Fuertes paleosismos de intraplaca y sus retornos vinculados a la falla Las Lagunas, Sierras Pampeanas de Cordoba Strong intraplate paleoearthquakes and their recurrence related to Las Lagunas fault, Sierras Pampeanas of Cordoba

    Directory of Open Access Journals (Sweden)

    Guillermo L Sagripanti

    2011-03-01

    Full Text Available En la intraplaca argentina, a la latitud 33°S, región sur de la provincia de Córdoba, la presencia de morfologías superficiales y deformaciones en sedimentos sueltos cuaternarios hacen suponer que la actividad tectónica neógena tuvo continuidad en el Holoceno y que seguramente fue acompañada por la ocurrencia de paleoterremotos. Los objetivos del presente trabajo son, por medio de investigaciones paleosismológicas realizar la reconstrucción del registro de la sismicidad prehistórica de la región y una estimación del potencial sismogénico de una fuente, con probada actividad cuaternaria, que sean de base en la estimación del riesgo sísmico de la región. Se excavaron seis trincheras transversales a la traza de la falla Las Lagunas, en sedimentos de origen eólico, fluvial y lagunar, en las cuales se relevaron estructuras cosísmicas, deformacionales y de licuefacción, de escala mesoscópica. Los resultados obtenidos han permitido proponer un modelo de retrodeformación para la falla, calcular el período de recurrencia de fuertes terremotos que es del orden de 1,2 - 2,0 Ka, calcular la magnitud de algunos paleo-eventos, Ms > 6,6 y hacer una estimación de la magnitud del terremoto máximo.Evidences like landforms and deformations in loose quaternary sediments, in the argentinian intraplate, at latitude 33° S, southern part of the Cordoba province, suggest that the Neogene tectonic activity continues into the Holocene and certainly had been associated to strong paleoearthquakes. The objectives of this work are to make a reconstruction of the prehistoric seis-micity record of the region by paleoseismological investigations, and to estimate the seismogenic potential of a source with proven Quaternary activity, with the aim of setting the basis to estimate the seismic risk of the region. Six trenches were dug across the trace of the Las Lagunas fault, cutting eolian, fluvial, and lagoon sediments. In the sites, several coseismic

  10. Dinámica e implicancia del aluvión de la laguna 513, Cordillera Blanca, Ancash, Perú Dinamics and implications of the laguna 513 Aluvion, Cordillera Blanca, Ancash Perú

    Directory of Open Access Journals (Sweden)

    Patricio Valderrama

    2012-09-01

    Full Text Available La Cordillera Blanca, al norte de Perú, es la zona con más actividad geodinámica externa en Perú. En ella ocurrieron grandes flujos de detritos de origen glaciar, varios de ellos fueron grandes desastres y cobraron miles de vidas. El 11 de abril del 2010, la laguna 513, ubicada en el centro de la Cordillera Blanca, sufrió un desembalse parcial por la caída de un gran bloque de hielo y rocas del nevado Hualcán (5500 m.s.n.m.. Este evento pese a ser de dimensiones considerables, no generó grandes pérdidas ni afectó alguna ciudad importante. Mediante simulaciones numéricas de flujo se estudió su dinámica, se determinó sus volúmenes y su turbulencia así como también explicamos e papel de la morfología de la zona en la desaceleración del flujo, su encausamiento en un valle fluvial y su posterior comportamiento como crecida de río. Las simulaciones realizadas mediante FLO2D se validan mediante comparaciones con imágenes de satélite post evento y datos de campo.The Cordillera Blanca in northern Peru is the most external geodynamics active areas in Perú. There have been occurred the biggest glacier source debris flow in the Peruvian history, most of them became on major disasters and claimed thousands of lives. On April 11th, 2010, the Laguna 513, located in the center of the Cordillera Blanca, suffered a partial GLOF due a massive rock and ice fall from Nevado Hualcán (5500 masl. This event, despite being of considerable size, did not generate large losses or affect any major city. Using numerical simulations we study the dynamics of the consequent GLOF and debris flow. We determined the volume and turbulence as well as also explained the role of the geomorphology of the area in the flow deceleration process and the river flood subsequent behavior. The FLO 2D simulations are validated with post event satellite image and field data.

  11. Analysis of the ecosystem structure of Laguna Alvarado, western Gulf of Mexico, by means of a mass balance model

    Science.gov (United States)

    Cruz-Escalona, V. H.; Arreguín-Sánchez, F.; Zetina-Rejón, M.

    2007-03-01

    Alvarado is one of the most productive estuary-lagoon systems in the Mexican Gulf of Mexico. It has great economic and ecological importance due to high fisheries productivity and because it serves as a nursery, feeding, and reproduction area for numerous populations of fishes and crustaceans. Because of this, extensive studies have focused on biology, ecology, fisheries (e.g. shrimp, oysters) and other biological components of the system during the last few decades. This study presents a mass-balanced trophic model for Laguna Alvarado to determine it's structure and functional form, and to compare it with similar coastal systems of the Gulf of Mexico and Mexican Pacific coast. The model, based on the software Ecopath with Ecosim, consists of eighteen fish groups, seven invertebrate groups, and one group each of sharks and rays, marine mammals, phytoplankton, sea grasses and detritus. The acceptability of the model is indicated by the pedigree index (0.5) which range from 0 to 1 based on the quality of input data. The highest trophic level was 3.6 for marine mammals and snappers. Total system throughput reached 2680 t km -2 year -1, of which total consumption made up 47%, respiratory flows made up 37% and flows to detritus made up 16%. The total system production was higher than consumption, and net primary production higher than respiration. The mean transfer efficiency was 13.8%. The mean trophic level of the catch was 2.3 and the primary production required to sustain the catch was estimated in 31 t km -2 yr -1. Ecosystem overhead was 2.4 times the ascendancy. Results suggest a balance between primary production and consumption. In contrast with other Mexican coastal lagoons, Laguna Alvarado differs strongly in relation to the primary source of energy; here the primary producers (seagrasses) are more important than detritus pathways. This fact can be interpreted a response to mangrove deforest, overfishing, etc. Future work might include the compilation of

  12. Abundancia y estructura poblacional de Crocodylus acutus (Reptilia: Crocodylidae en la laguna Palmasola, Oaxaca, México

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    Jesús García-Grajales

    2014-03-01

    Full Text Available La abundancia y estructura poblacional son pará-metros importantes para evaluar y comparar el estatus de conservación de una población a través del tiempo en un área determinada. Este estudio describe la abundancia y estructura poblacional de Crocodylus acutus en la laguna Palmasola, Oaxaca. El trabajo consistió en recorridos nocturnos, entre las 21 y 24h, durante la fase de luna nueva para contabilizar el número de individuos y obtener estimaciones poblacionales. El tamaño poblacional estimado fluctuó de 32.7 a 93 individuos según el modelo utilizado. Las tasas de encuentro registradas fluctuaron de 32 a 109.3 ind/km lineal durante los 40 recorridos efectuados con un tiempo promedio de navegación de 18 minutos. Existió una marcada dominancia de la clase III (subadultos, seguido por la clase II y en menor proporción las clases IV y V, así como aquellos individuos en los que no se pudo determinar el tamaño corporal, en ambas épocas del año. Mientras tanto, los individuos juveniles (Clase II se observaron en mayor proporción asociados al manglar que cubre las orillas del cuerpo de agua (26.1%, los individuos subadultos (Clase III a menudo se observaron sobre el espejo de agua sin vegetación flotante (22.7% y entre el manglar que cubre las orillas del cuerpo de agua (15.7%, mientras que los ejemplares adultos se observaron con mayor frecuencia sobre el espejo de agua sin vegetación flotante (9.7%. Con la presente información se contribuye al conocimiento de la ecología poblacional de C. acutus en la laguna Palmasola donde el tamaño poblacional estimado parece mostrar valores altos con respecto a lo reportado en otros estados de la República Mexicana.

  13. Variables ambientales y abundancia de los huevos de Anchoa mitchilli (Pisces: Engraulidae en la laguna de Tamiahua, México

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    Carlos Díaz-Avalos

    2003-06-01

    Full Text Available Se estudió la abundancia de huevos de Anchoa mitchilli (Cuvier y Valenciennes 1848 en la laguna de Tamiahua, Ver. durante tres ciclos anuales (84-85, 85-86 y 86-87, para determinar zonas y épocas de alta concentración de huevos y su posible asociación con variables como temperatura, salinidad, transparencia y profundidad, así como con factores espacio-temporales como posición geográfica, época climática y el ciclo anual de recolecta. Para probar estadísticamente la asociación de la abundancia de huevos con dichos factores y variables se ajusto un Modelo Lineal Generalizado (MLG con error tipo Gamma. Los resultados del modelo ajustado sugieren que no todas las variables tienen un efecto significativo sobre la abundancia de huevos (t de Student, p >0.05. Las variables que resultaron estadísticamente significativas indican la presencia de un componente estacional y que la salinidad tiene un efecto condicional a la localidad. Las mayores abundancias promedio durante los tres ciclos de recolecta ocurrieron siempre durante el verano. Asimismo, debido a la presencia de interacciones significativas (t de Student, pEgg abundance of Anchoa mitchilli was studied in Laguna de Tamiahua, Veracruz during three annual cycles (84-85, 85-86 and 86-87. Our goal was to detect areas and seasons with high egg abundance and the possible association of such areas and seasons with covariates such as temperature, salinity, transparency, depth, location, season and year. The association was tested statistically using a Generalized Linear Model (GLM with Gamma type error. The results suggest that not all the covariates considered have a significant effect on egg abundance (Student’s T, p>0.005. The significant effects show the presence of a seasonal component and that the effect of salinity on egg abundance is conditional to location. High average egg abundances for the three annual cycles were observed during summer. The presence of significant interactions

  14. Impact of flow induced vibration acoustic loads on the design of the Laguna Verde Unit 2 steam dryer

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, D. R.; Wellstein, L. F.; Theuret, R. C.; Han, Y.; Rajakumar, C. [Westinghouse Electric Company LLC, Cranberry Township, PA 16066 (United States); Amador C, C.; Sosa F, W., E-mail: forsytdr@westinghouse.com [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Km 42.5 Carretera Cardel-Nautla, 91680 Alto Lucero, Veracruz (Mexico)

    2015-09-15

    Industry experience with Boiling Water Reactors (BWRs) has shown that increasing the steam flow through the main steam lines (MSLs) to implement an extended power up rate (EPU) may lead to amplified acoustic loads on the steam dryer, which may negatively affect the structural integrity of the component. The source of these acoustic loads has been found to be acoustic resonance of the side branches on the MSLs, specifically, coupling of the vortex shedding frequency and natural acoustic frequency of safety relief valves (SRVs). The resonance that results from this coupling can contribute significant acoustic energy into the MSL system, which may propagate upstream into the reactor pressure vessel steam dome and drive structural vibration of steam dryer components. This can lead to high-cycle fatigue issues. Lock-in between the vortex shedding frequency and SRV natural frequency, as well as the ability for acoustic energy to propagate into the MSL system, are a function of many things, including the plant operating conditions, geometry of the MSL/SRV junction, and placement of SRVs with respect to each other on the MSLs. Comision Federal de Electricidad and Westinghouse designed, fabricated, and installed acoustic side branches (ASBs) on the MSLs which effectively act in the system as an energy absorber, where the acoustic standing wave generated in the side-branch is absorbed and dissipated inside the ASB. These ASBs have been very successful in reducing the amount of acoustic energy which propagates into the steam dome. In addition, modifications to the Laguna Verde Nuclear Power Plant Unit 2 steam dryer have been completed to reduce the stress levels in critical locations in the dryer. The objective of this paper is to describe the acoustic side branch concept and the design iterative processes that were undertaken at Laguna Verde Unit 2 to achieve a steam dryer design that meets the guidelines of the American Society of Mechanical Engineers, Boiler and Pressure

  15. Nuevas evidencias geofísicas de la existencia de una caldera cubierta en laguna Pozuelos: Puna norte

    Directory of Open Access Journals (Sweden)

    Claudia B Prezzi

    2010-03-01

    Full Text Available En el extremo sur de la cuenca de laguna de Pozuelos aflora el complejo volcánico Pan de Azúcar. El mismo está integrado por varios centros eruptivos de composición dacítica y morfología dómica que poseen una edad de ~12 Ma. Interpretaciones previas de líneas sísmicas y un relevamiento magnetométrico detallado indicaron la presencia de cuerpos intrusivos no aflorantes. La determinación de la existencia de nuevos cuerpos intrusivos no aflorantes en la zona resulta de interés debido a que: 1 estos complejos volcánicos dacíticos están estrechamente asociados con mineralización de interés económico (forman parte del cinturón estañífero boliviano; y 2 la existencia de una caldera antigua (~ 12 Ma de grandes dimensiones, ahogada bajo la cubierta sedimentaria que rellena la depresión de Pozuelos, ha sido propuesta por distintos autores. Los complejos dómicos representarían las fases magmáticas finales de dicho sistema magmático caldérico. Con la finalidad de determinar la existencia de dicho sistema caldérico y/o de otros cuerpos intrusivos no aflorantes se llevaron a cabo nuevos relevamientos magnetométricos y gravimétricos terrestres detallados. El mapa magnetométrico obtenido presenta conspicuas anomalías positivas y negativas que dominan el sector sur de la cuenca, probablemente asociadas con la presencia de los domos dacíticos aflorantes. La anomalía residual de Bouguer presenta un patrón semicircular, mostrando sólo valores positivos. La curvatura de las señales magnetométricas y gravimétricas fue analizada y se utilizó la deconvolución de Euler para estimar las profundidades a las fuentes causantes de las anomalías detectadas. Los resultados obtenidos hasta el momento apoyan la hipótesis de la existencia de una gran caldera soterrada en la cuenca de Laguna Pozuelos. La identificación de un gran sistema caldérico mioceno medio contribuirá a una mejor comprensión de la evolución magmática de la Puna

  16. Limnology in El Dorado: some surprising aspects of the regulation of phytoplankton productive capacity in a high-altitude Andean lake (Laguna de Guatavita, Colombia).

    Science.gov (United States)

    Donato, Jhon; Jimenez, Paola; Reynolds, Colin

    2012-09-01

    High-altitude mountain lakes remain understudied, mostly because of their relative inaccessibility. Laguna de Guatavita, a small, equatorial, high-altitude crater lake in the Eastern Range of the Colombian Andes, was once of high cultural importance to pre-Columban inhabitants, the original location of the legendary El Dorado. We investigated the factors regulating the primary production in Laguna de Guatavita (4degrees58'50" N - 73degrees46'43" W, alt. 2 935m.a.s.l., area: 0.11km2, maximum depth: 30m), during a series of three intensive field campaigns, which were conducted over a year-long period in 2003-2004. In each, standard profiles of temperature, oxygen concentration and light intensity were determined on each of 16-18 consecutive days. Samples were collected and analysed for chlorophyll and for biologically-significant solutes in GF/F-filtered water (NH4+, NO3(-), NO2(-); soluble reactive phosphorus). Primary production was also determined, by oxygen generation, on each day of the campaign. Our results showed that the productive potential of the lake was typically modest (campaign averages of 45-90mg C/m2.h) but that many of the regulating factors were not those anticipated intuitively. The lake is demonstrably meromictic, reminiscent ofkarstic dolines in higher latitudes, its stratification being maintained by solute- concentration gradients. Light penetration is poor, attributable to the turbidity owing to fine calcite and other particulates in suspension. Net primary production in the mixolimnion of Laguna de Guavita is sensitive to day-to-day variations in solar irradiance at the surface. However, deficiencies in nutrient availability, especially nitrogen, also constrain the capacity of the lake to support a phytoplankton. We deduced that Laguna de Guatavita is something of a limnological enigma, atypical of the common anticipation of a "mountain lake". While doubtlessly not unique, comparable descriptions of similar sites elsewhere are sufficiently

  17. Patrones de variación espacial y temporal de los macroinvertebrados acuáticos en la Laguna de Tecocomulco, Hidalgo (México

    Directory of Open Access Journals (Sweden)

    Axel Eduardo Rico-Sánchez

    2014-04-01

    Full Text Available La Laguna de Tecocomulco (Hidalgo es un relicto de los antiguos Lagos del Anáhuac con suma importancia para la conservación de aves acuáticas. No obstante, se desconoce su composición de macroinvertebrados. En el presente estudio se analizaron las variaciones espaciales y temporales de los macroinvertebrados acuáticos de la laguna. Se realizaron cuatro campañas de monitoreo (lluvias y estiaje. Se estudiaron seis sitios (litorales y en interior de la laguna, se registraron factores ambientales, se determinaron parámetros de calidad del agua y se recolectaron macroinvertebrados acuáticos. Se obtuvo la riqueza de familias y se calculó su Índice de Valor de Importancia. Se realizaron análisis multivariados de ordenación por componentes principales (ACP con base en sus características físicas y químicas y de similitud entre sitios y familias con los índices de Jaccard y Bray-Curtis. Tambien se hizo un análisis de correspondencias canónicas (ACC de factores ambientales y macroinvertebrados acuáticos y macrófitas. El ACP mostró la variación estacional, con el período cálido (mayo y agosto y el periodo frío (noviembre y enero mostrando altos valores de conductividad, alcalinidad, dureza, sulfatos y macronutrientes (N y P. Se encontraron 26 familias de macroinvertebrados, con la máxima riqueza en agosto. El análisis de similitud de Jaccard diferenció los sitios litorales por su mayor riqueza de familias de la zona limnética, mismos que presentan diferencias en la composición de macrófitas. El estudio revela que la Laguna de Tecocomulco tiene variaciones espaciales y temporales relacionadas tanto con factores ambientales como bióticos con la presencia de grupos dominantes. En ese sentido, y considerando su diversidad de macroinvertebrados, la Laguna de Tecocomulco debe ser sujeta a un plan de conservación y manejo.

  18. Development of a methodology for the economical analysis of fuel cycles, application to the Laguna Verde central; Desarrollo de una metodologia para el analisis economico de ciclos de combustible, aplicacion a la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Malfavon, S.M.; Trejo, M.G.; Hernandez, H. [FI-UNAM, 04500 Mexico D.F. (Mexico); Francois, J.L.; Ortega, R.F. [FI-UNAM, Paseo Cuauhnahuac 8532, Jiutepec, Morelos (Mexico)

    2003-07-01

    In this work a methodology developed to carry out the economical analysis of the fuel cycle of a nuclear reactor is presented. The methodology was applied to the Laguna Verde Nuclear Power Station (CNLV). The design of the reload scenarios of the CNLV are made with the Core Master Presto code (CM-Presto), three-dimensional simulator of the reactor core, the launched data by this, as well as the information of the Energy use plan (PUE), it allowed us to obtain reliable results through the fitness of an algorithm of economic calculation that considers all the components of the fuel cycle to present worth. With the application of the methodology it was obtained the generated energy, as well as their respective cost of each sub lot type of assemblies by operation cycle, from the start-up of the CNLV until September 13, 2002. Using the present worth method its were moved all the values at November 5, 1988, date of operation beginning. To the final of the analysis an even cost of 6.188 mills/kWh was obtained for those first 9 cycles of the Unit 1 of the CNLV, being observed that the costs of those first 3 operation cycles are the more elevated. Considering only the values starting from the cycle 4, the levelled cost turns out to be of 5.96 mills/kWh. It was also obtained the cost by fuel lot to evaluate the performance of assemble with the same physical composition. (Author)

  19. Evaluation of radwaste minimization program of dry and wet active waste in the Laguna Verde Nuclear Power Plant; Evolucion del programa de minimizacion de desechos solidos secos y humedos en la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Luna-Garza, Hector [Comision Federal de Electricidad, Veracruz (Mexico). Central Nucleoeletrica Laguna Verde; Zarate-Montoya, Norma [Instituto Nacional de Investigaciones Nucleares, Veracruz (Mexico)

    2001-07-01

    A growing rate of radwaste volume production combined with an increase of both, costs and associated dose involved in its treatment and disposition processes have created a serious problem to the Laguna Verde Nuclear Power Plant (BWR, two Units, 682 Mwe each) in Mexico. Due the lack of a Final Repository in the country, the solution in the short or long terms relies on the success of a continuous and aggressive minimization program mainly based on modifications and upgrades applied to these processes. Technical and administrative strategies adopted by LVNPP for the reduction of Liquid Effluents and Dry and Wet Active Waste in the next three years are described. Based on the results of the LVNPP current radwaste process systems, an estimated accumulation of 11,502 m{sup 3} by the year 2035 will exceed the actual on-site storage capacity. If the strategies succeed, this production would fall to an expected manageable volume of 4067 m{sup 3}. (author)

  20. NucleoRed - Computerized system for increasing the effectiveness of the technical administrative conduct of the Laguna Verde Central; NucleoRed - Sistema computarizado para incrementar la efectividad de la gestion tecnico-administrativa de la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Luna D, J. [Central Nucleoelectrica Laguna Verde, Carretera cardel-Nautla Km. 42.5 Veracruz (Mexico)]. e-mail: jluna@cfe.gob.mx

    2003-07-01

    The on-line systems for the management of the Laguna Verde Central (CLV) have had the challenge to evolve from the PC's of first generation until emigrate to the new Internet technologies, so that they allow to the diverse work groups to have the computer tool that allows them to gather the necessary data and to carry out efficiently the analysis of their results. To confront the previous challenge, in the CLV it has been developed and implemented the Nucleo Red that is an on-line system with the objective of providing in it lines strategic information for the Technician-administrative management of the plant in the nuclear context. The Nucleo Red is the computational tool that reflects the technical administrative processes implemented by personnel of the different Operative departments, it seeks to cooperate to the reliable and efficient operation of the first nucleo electric central of Mexico, with technology and Mexican personnel the one which already it had received international recognitions. The perspective of this computer system is to continue inside the process of continuous improvement and that although it was designed for a nucleo electric plant it can also be taken to the conventional plants of generation of electric power, so that this technology can be taken advantage of in other non nuclear facilities. The objective of the present work, is to show the new modules that have been developed in the Nucleo Red, its operation in general, and the benefits that it presents its use. (Author)

  1. Technological evaluation for the extension of the operation license to the nuclear power plant of Laguna Verde; Evaluacion tecnologica para la extension de la licencia de operacion de la Central Nucleoelectrica Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Arganis J, C. R.; Medina A, A. L., E-mail: carlos.arganis@inin.gob.m [ININ, Departamento de Tecnologia de Materiales, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-07-01

    At the present time one of the tendencies in the nuclear industry is the renovation of operation licenses of the nuclear power plants, with the purpose of prolonging their operation 20 years more than the time settled down in their original license, which is of 30 years for the case of the nuclear power plant of Laguna Verde. This allows the electric power generation for a major period of time and to a relatively low price, giving this way a bigger competitiveness to the power stations of nuclear power. However, to request the license extension of the nuclear power plant requires to get ready the documentation and necessary studies for: to maintain a high level of security, to optimize the operation, maintenance and service life of the structures, systems and components, to maintain an acceptable level of performance, to maximize the recovery of the investment about the service of the nuclear power plant and to preserve the sure conditions for a major operation period at the license time. This paper describes the studies conducted by the Materials Technology Department of the Instituto Nacional de Investigaciones Nucleares (ININ) to substantiate the required documentation for obtaining the extension of operating license of the nuclear power plant. These studies are focused mainly in the reactor pressure vessels of both units, as well as in the deposit of noble metals and the influence of the sludges (crud s) in this deposit. (Author)

  2. Temporary storage in dry of the spent nuclear fuel in the Nuclear Power Plant of Laguna Verde; Almacenamiento temporal en seco del combustible nuclear gastado en la Central Nuclear Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, N.; Vargas A, A., E-mail: natividad.hernandez@cfe.gob.mx [Comision Federal de Electricidad, Gerencia de Centrales Nucleoelectricas, Carretera Veracruz-Medellin Km. 7.5, 94270 Dos Bocas, Veracruz (Mexico)

    2013-10-15

    To guarantee the continuity in the operation of the two nuclear reactors of the nuclear power plant of Laguna Verde (NPP-L V) is an activity of high priority of the Comision Federal de Electricidad (CFE) in Mexico. At the present time, the CFE is working in the storage project in dry of the spent fuel with the purpose of to liberate space of the pools and to have the enlarged capacity of storage of the spent fuel that is discharged of the reactors. This work presents the storage option in dry of the spent fuel, considering that the original capacity of the spent fuel pools of the NPP-L V was of 1242 spaces each one and that in 1991, through a modification of the original design, the storage capacity was increased to 3177 spaces by pool. At present, the cells occupied by unit are of 2165 (68%) for the Unit-I and 1839 (58%) for the Unit-2, however, in 2017 and 2022 the capacity to discharge the complete core will be limited by what is required of a retirement option of spent fuel assemblies to liberate spaces. (author)

  3. Experiences in the implementation of the Coaching project in the nuclear power plant of Laguna Verde (NPP-L V); Experiencias en la implementacion del proyecto Coaching en la Central Nucleoelectrica Laguna Verde (CNLV)

    Energy Technology Data Exchange (ETDEWEB)

    Mendez M, H. I., E-mail: hugo.mendez01@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Departamento del Centro de Entrenamiento, Carretera Cardel-Nautla Km 42.5, Alto Lucero, Veracruz (Mexico)

    2012-10-15

    This document has the purpose of to share acquired experiences during the implementation of the Coaching project focused the training of supervisors and directive personnel of the nuclear power plant of Laguna Verde (NPP-L V). Derived of the improvement areas identified by the supervisor organization of the nuclear power stations WANO (World Association Nuclear of Operators) and of the auto-evaluations realized by the expert personnel of the same power station that based on external experiences carried out through the Benchmarking (comparison with other power stations) they have reflected the necessity to activate a training process in Coaching with a practical focus toward the directive and supervisor personnel in the power station. By means of the observation of the personnel's acting so much in the control rooms like in different areas, three focus areas have been identified for the training in Coaching, these are the personnel's motivation, the organizational communication so much in vertical form as horizontal and the perception of confidence lack among directive, supervisors, operators and technicians. The plan focused in the abilities training of Coaching with practical sense was development, supported with an evaluation of 360 grades as tool of competitions development through a computer application e-Coaching. The use of application and Coaching following techniques facilitated the conformation of the practical focus, same that are of continuous use starting from the training of the supervisor and directive personnel. (Author)

  4. Analysis of the preliminary trajectory of emergency venting of the nuclear power plant of Laguna Verde using RELAP5; Analisis de la trayectoria preliminar del venteo de emergencia de la Central Laguna Verde mediante RELAP5

    Energy Technology Data Exchange (ETDEWEB)

    Cecenas F, M.; Jimenez S, R.; Ovando C, R. [Instituto Nacional de Electricidad y Energias Limpias, Reforma No. 113, Col. Palmira, 42490 Cuernavaca, Morelos (Mexico); Tijerina S, F.; Tapia M, R. N., E-mail: mcf@iie.org.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Subgerencia de Ingenieria, Carretera Veracruz-Medellin Km. 7.5, 94271 Veracruz (Mexico)

    2016-09-15

    For a commercial nuclear plant, the availability of a vent line to the atmosphere is an improvement to achieve the prevention and mitigation of the consequences of a severe accident. The importance of this system received greater attention after the Fukushima accident in 2011. Subsequently, in 2012 and 2013, the United States Nuclear Regulatory Commission issued documents stating that the venting must be able to dislodge 1% of the rated thermal power of the core without over pressurizing the primary container. To analyze the venting of the nuclear power plant of Laguna Verde, the line and the primary container are modeled using the thermo-hydraulic code RELAP5, simulating a release of 1% of the nominal licensed power to the container in the form of saturated steam. The vent has no problem to evacuate the energy and manages to keep the container without exceeding its design limit, and the highest percentage of thermal power that can channel the vent to the outside is approximately 3%. A sensitivity analysis increasing the diameter of the line to 14 inches allows increasing in 10% the percentage of power that can be vented to the outside without problem for the containment. (Author)

  5. Feasibility analysis in the expansion proposal of the nuclear power plant Laguna Verde: application of real options, binomial model; Analisis de viabilidad en la propuesta de expansion de la central nucleoelectrica Laguna Verde: aplicacion de opciones reales, modelo binomial

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez I, S.; Ortiz C, E.; Chavez M, C., E-mail: lunitza@gmail.com [UNAM, Facultad de Ingenieria, Circuito Interior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2011-11-15

    At the present time, is an unquestionable fact that the nuclear electrical energy is a topic of vital importance, no more because eliminates the dependence of the hydrocarbons and is friendly with the environment, but because is also a sure and reliable energy source, and represents a viable alternative before the claims in the growing demand of electricity in Mexico. Before this panorama, was intended several scenarios to elevate the capacity of electric generation of nuclear origin with a variable participation. One of the contemplated scenarios is represented by the expansion project of the nuclear power plant Laguna Verde through the addition of a third reactor that serves as detonator of an integral program that proposes the installation of more nuclear reactors in the country. Before this possible scenario, the Federal Commission of Electricity like responsible organism of supplying energy to the population should have tools that offer it the flexibility to be adapted to the possible changes that will be presented along the project and also gives a value to the risk to future. The methodology denominated Real Options, Binomial model was proposed as an evaluation tool that allows to quantify the value of the expansion proposal, demonstrating the feasibility of the project through a periodic visualization of their evolution, all with the objective of supplying a financial analysis that serves as base and justification before the evident apogee of the nuclear energy that will be presented in future years. (Author)

  6. Analysis of a natural draught tower in the circulation seawater system of nuclear power plant of Laguna Verde; Analisis de una torre de tiro natural en el sistema de agua de circulacion de mar de la central nucleoelectrica Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Tijerina S, F.; Vargas A, A. [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Subgerencia de Ingenieria, Carretera Veracruz-Medellin Km. 7.5, Veracruz (Mexico)], e-mail: francisco.tijerina@cfe.gob.mx

    2009-10-15

    The analysis of a natural draught tower in open circuit for the cooling system of seawater circulation on the nuclear power plant of Laguna Verde, it is based on conditions of 2027 MWt and 2317 MWt, where the flows of circulation water system hardly vary and whose purpose will be, to cool the seawater circulation. The circulation water system is used as heat drain in main condenser of turbo generator to condense the nuclear vapor. The annual average temperature in the seawater at present is of 26 C to the entrance to circulation water system and it is vary in accordance with the time of year. The mean temperature of leaving of circulation water system to the sea is of 41 C. Having a cooling tower to reduce the entrance temperature to the circulation water system, it improves the efficiency of thermal transfer in condenser, it improves the vacuum in condenser giving more operative margin to avoid condenser losses by air entrances and nuclear power plant shutdowns, as well as for to improve the efficiency of operative balance of nuclear power plant, also it prevents the impact in thermal transfer efficiency in condenser by the climatic change. (Author)

  7. Questions to the reactors power upgrade of the Nuclear Power Plant of Laguna Verde; Cuestionamientos al aumento de potencia de los reactores de la Central Nuclear de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Salas M, B., E-mail: salasmarb@yahoo.com.mx [UNAM, Facultad de Ciencias, Departamento de Fisica, Circuito exterior s/n, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2014-08-15

    The two reactors of the Nuclear Power Plant of Laguna Verde (NPP-L V) were subjected to power upgrade labors with the purpose of achieving 20% upgrade on the original power; these labors concluded in August 24, 2010 for the Reactor 1 and in January 16, 2011 for the Reactor 2, however in January of 2014, the NNP-L V has not received by part of the Comision Nacional de Seguridad Nuclear y Salvaguardias (CNSNS) the new Operation License to be able to work with the new power, because it does not fulfill all the necessary requirements of safety. In this work is presented and analyzed the information obtained in this respect, with data provided by the Instituto Federal de Acceso a la Informacion Publica y Proteccion de Datos (IFAI) and the Comision Federal de Electricidad (CFE) in Mexico, as well as the opinion of some workers of the NPP-L V. The Governing Board of the CFE announcement that will give special continuation to the behavior on the operation and reliability of the NPP-L V, because the frequency of not announced interruptions was increased 7 times more in the last three years. (Author)

  8. Relative frequencies of deletereo genes in populations of droshopila Melanogaster from Laguna Verde, Veracruz; Frecuencias relativas de genes deletereos en poblaciones de Drosophila melanogaster originarias de Laguna Verde, Veracruz

    Energy Technology Data Exchange (ETDEWEB)

    Salceda, V. M. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: vmss@nuclear.inin.mx

    2008-07-01

    In order to obtain data about the possible changes and/or damages that could cause the operation of the reactors of the nuclear power plant of Laguna Verde to the populations of drosophila Melanogaster that lives in the zone, one carried out one series of biannual collections (summer and winter) during the years 1991-1992 and 1996-1998 to obtain individuals of this species and to subject them to a battery of tests. The flies of this species that it was possible to capture were transported to the Biology Laboratory of the National Institute of Nuclear Research, where they were put under in individual form a series of you cross they allowed that us in the third generation to detect the presence of deletereo genes that following their viability were catalogued like normal, lethal or less lethal according to the methodology of Wallace. This way a total of 933 second chromosomes was analyzed to leave of them the relative frequencies were calculated of each one of the categories, for each sample station. The result of the applied statistical test indicates us that not significant difference exists among the populations and that the differences of having them must only to the environment changes something that usually happen in all the population. For what we can point out that the presence of the reactors does not seem to influence negatively in the behavior of the population that lives in the zone. (Author)

  9. El consumo de sustancias psicoactivas en estudiantes de Psicología de la Universidad de la Laguna

    Directory of Open Access Journals (Sweden)

    Conrado M. Viña

    2004-01-01

    Full Text Available El presente estudio descriptivo ha tenido como principales objetivos explorar la extensión del consumo de distintas sustancias psicoactivas tanto legales como ilegales y comprobar si éstas se consumen de manera diferencial en ambos géneros. Además, se ha tratado de detectar la posible presencia de patrones de policonsumo y si éstos también variaban en función del género. El estudio se ha llevado a cabo sobre una muestra de 544 estudiantes de ambos géneros (84% mujeres y 16% hombres de la Facultad de Psicología de la Universidad de La Laguna, con un diseño descriptivo transversal mediante encuestas. Se realizaron diversos análisis multivariados: análisis discriminantes, análisis de regresión y análisis factoriales. Los resultados indican que las drogas más utilizadas en esta muestra universitaria fueron dos sustancias legales (alcohol y tabaco y una ilegal (cannabis. Además, se encontraron diferencias en función del género en el consumo de sustancias tales como la cocaína, las anfetaminas, el cannabis, el alcohol y otras sustancias. Los análisis factoriales aislaron patrones claros de policonsumo.

  10. Knowledge, Attitude and Practices towards Leptospirosis among Lakeshore Communities of Calamba and Los Baños, Laguna, Philippines

    Directory of Open Access Journals (Sweden)

    Joseph Arbiol

    2016-04-01

    Full Text Available Leptospirosis is a serious and potentially fatal zoonotic disease, but often neglected owing to lack of awareness. This study examined the knowledge, attitudes, and practices concerning leptospirosis among agricultural (n = 152 and non-agricultural (n = 115 workers in the lakeshore communities of Calamba and Los Baños, Laguna, Philippines. The findings showed no significant differences for the knowledge and attitude scores between agricultural and non-agricultural workers. However, agricultural workers had significantly lower prevention practice scores than non-agricultural workers. The ordinary least squares regression model identified gender, use of broadcast media as a source of health information, and knowledge and attitudes about leptospirosis as significant predictors of prevention practices common to both workers. Higher educational attainment was significantly associated with prevention practices among agricultural workers, while higher age and income level were significantly associated with prevention practices among non-agricultural workers. Public health interventions to improve leptospirosis knowledge and prevention practices should include health education and promotion programs, along with the strengthening of occupational health and safety programs in the agricultural sector.

  11. [The feeding ecology of the endemic fish Girardinichthys multiradiatus (Cyprinidontiformes: Goodeidae) in Lagunas of Zempoala National Park, Mexico].

    Science.gov (United States)

    Trujillo-Jiménez, Patricia; Monteros Viveros, Efrén Espinosa de los

    2006-12-01

    Girardinichthys multiradiatus, locally known as "mexcalpique", is a small endemic fish of the Lerma river basin. Its presence in lakes (Zempoala) suggests a long-standing connection between these lakes and the river basin. The current range of this species in the Mexico and Toluca valley appears to have been reduced, making this park a refuge for the species. Nevertheless, little is known about its biology. We studied its diet and feeding habits in Acoyotongo Lake, Lagunas de Zempoala National Park (19 degrees 01'30"-19 degrees 06' N, 99 degrees 16'20"-99 degrees 21' W) where seasonal collections were carried out. The gut contents of 97 specimens were identified to the most specific taxonomic category possible and analyzed with numeric and frequency of occurrence methods. The general diet of this species consists of twelve dietary components, eleven of which are of animal origin. Hymenopterans, springtails and chironomids represented the highest percentage of ingestion and preference. G. multiradiatus is as a carnivorous species with entomophagous tendencies.

  12. The capturing of pollens in the atmosphere of La Laguna City, Tenerife, Canary Islands 1990-1995.

    Science.gov (United States)

    García Cobaleda, I; De la Torre Morin, F; García Robaina, J C; Hardisson de la Torre, A

    1997-01-01

    This paper forms part of a Doctorate Thesis, carried out in the Allergy and Immunology Department of the Nuestra Señora de la Candelaria Hospital, Tenerife, entitled "Epidemiology of Pollens on the Island of Tenerife. Allergy to Pollen". This paper deals with the capturing of pollen in the atmosphere of the city of La Laguna, Tenerife, during the period 1990-1995, and demonstrates that the Occidental Islands of the Canarian Archipelago are similar to a miniature continent with a special microclimate and a large amount of vegetation, where all classes of pollen can be found given the large variety of plants and trees including native species. High concentrations of more than 50 grains of pollen per m3 can be found in the air of the Occidental Islands, above all wild grasses, cultivated grasses, weeds, Artemisa vulgaris, Parietaria officinalis and Plantago lanceolata, and in a lowe proportion, Cupressaceae, Pinaceas, Mercurialis and Rumex. We have pollen concentrations very similar to other parts of the continent.

  13. EVALUACIÓN PRELIMINAR DE LAS COMUNIDADES DE MACROINVERTEBRADOS BENTÓNICOS DE LA LAGUNA DE QUISTOCOCHA, IQUITOS, PERÚ

    Directory of Open Access Journals (Sweden)

    Jemima Alván Alvarado

    2012-12-01

    Full Text Available El objetivo del presente trabajo fue realizar una evaluación preliminar de la riqueza y abundancia de las comunidades de macroinvertebrados bentónicos colectados en dos estratos (orilla y 1 metro de profundidad de la Laguna de Quistococha (Loreto, Perú. Las muestras de orilla fueron colectadas utilizándose una red de colecta de bentos (en forma de D con malla de 1 mm2, mientras que las de 1 m de profundidad fueron colectadas con una draga tipo Eckman, colectándose en total 30 muestras (15 de orilla y 15 de 1 m de profundidad. En la orilla se registró la mayor riqueza (11 especies y abundancia (109 individuos de macroinvertebrados bentónicos, en comparación con la de 1 m de profundidad, donde solo se registraron 5 especies y 51 individuos, registrándose diferencias significativas según la prueba de Mann-Whitney (P<0,05. Para todas las zonas de colecta, la especie Chironomus sp. fue la más abundante tanto en orilla (79 individuos, 72,48%, como a 1 m de profundidad (43 individuos, 84,31%.

  14. Estimation of seismic return periods in the Laguna Verde nuclear plant; Estimacion de periodos de retorno sismico en la PNLV

    Energy Technology Data Exchange (ETDEWEB)

    Flores R, J.H

    1992-01-15

    The study of seismic risk in the area of the Laguna Verde Nucleo electric plant (PNLV) and its surroundings, one carries out estimating the different return periods and the occurrence probability in different intervals of time (5, 75, 100, 125, 150 years starting from the distribution of first type of Gumbel (G1) of extreme values (Burton, 1986), the value that was used to evaluate the useful life of the PNLV was of 50 years, the other periods will be occupy to evaluate 'temporal' nuclear cemeteries, that is to say for diminish the radioactive activity of the fuel assemblies already burned in the reactor pool or in a near place to the place. The seismic data that were used for the analysis were of the seismic catalog that it was elaborated from (1920-1982), around the place whose seismic half magnitude was of 5 grades Richter and a depth 65 km, these earthquakes are classified as shallow earthquakes, which are located in the continental plaque of North-America, these they are induced by the efforts of push of the plaque of Cocos, existing 36% of intermediate and 2 of deep earthquakes. (Author)

  15. Flora vascular y vegetación de la laguna de Parinacochas y alrededores (Ayacucho, Perú

    Directory of Open Access Journals (Sweden)

    José E. Roque

    2013-03-01

    Full Text Available La laguna de Parinacochas, situada en el extremo sur del departamento de Ayacucho, a 3200 m de altitud, está considerada como un importante humedal altoandino; sin embargo, su riqueza florística es poco conocida. En un intento por cubrir este vacío de información botánica, se presentan los resultados de evaluaciones realizadas entre los años 2003—2006 en este ecosistema altoandino. La flora vascular está conformada por 234 taxones (225 especies y nueve taxones infraespecíficos, en 179 géneros y 73 familias; las Asteraceae, Poaceae y Fabaceae son las familias con más especies. Se encontraron siete tipos de vegetación, constituyendo los matorrales los más diversos. Veinte taxones, incluyendo cinco subespecies, son considerados endémicos para el país; se amplía, igualmente, el conocimiento sobre la distribución departamental de 93 taxones. La actividad ganadera constituye la principal amenaza antrópica, en tanto que otras actividades no representan riesgo potencial para la flora y vegetación de este ecosistema.

  16. Analysis of a signal during bistable flow events in Laguna Verde Nuclear Power Station with wavelets techniques

    Energy Technology Data Exchange (ETDEWEB)

    Nunez-Carrera, A. [Comision Nacional de Seguridad Nuclear y Salvaguardias, Doctor Barragan 779, Col. Narvarte, Mexico D.F. 03020 (Mexico); Prieto-Guerrero, A. [Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco, 186, Col. Vicentina, Mexico D.F. 09340 (Mexico); Espinosa-Martinez, E.-G. [Retorno Quebec 6, Col. Burgos de Cuernavaca 62580, Temixco, Mor. (Mexico); Espinosa-Paredes, G., E-mail: gepe@xanum.uam.m [Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco, 186, Col. Vicentina, Mexico D.F. 09340 (Mexico)

    2009-12-15

    This paper is concerned about bistable flow, which is manifested by a small and spontaneous change in the recirculation loop flow that has been reported in some Boiling Water Reactors. Here some real time series of the bistable flow from the Laguna Verde Nuclear Power Plant (LVNPP) are analyzed using a methodology based on wavelet transform. This methodology involves the decomposition of the original signal using the Continuous Wavelet Transform (CWT) and the application of the Discrete Wavelet Transform (DWT) based on the Multiresolution Analysis (MRA). The CWT provides information about ruptures, discontinuities and fractal behavior. The MRA allows a fast implementation of the Discrete Wavelet Transform providing information about frequencies, discontinuities and transients that can be detected with analysis at different levels of details coefficients. The combination of both techniques allows the definition of an integral methodology for the study of reactor signals. We found that the associated frequencies for the singularities observed due to bistable flow for the case of LVNPP, correspond to the interval 0.01-0.1 Hz.

  17. Influencia de la dispersión del flujo en la remoción de coliformes fecales en las lagunas secundarias de estabilización de Masaya

    Directory of Open Access Journals (Sweden)

    S. Gámez

    2006-08-01

    Full Text Available Lagunas de estabilización de aguas residuales domésticas en Nicaragua diseñadas para que el efluente no contenga un NMP de CF mayor que el indicado en el Decreto 33-95 “Normativas para el control de la contaminación proveniente de las descargas de aguas residuales domésticas, industriales y agropecuarias” no producen un efluente con esa calidad. Se realizaron estudios, para conocer el por qué de esta situación, en dos lagunas secundarias de estabilización de la ciudad de Masaya. Una laguna cuenta con pantallas deflectoras y por tanto un número de dispersión mucho menor que la segunda. Los resultados son: a La laguna secundaria con pantallas deflectoras produce un efluente con menos variaciones y menor NMPCF/100 ml; b El valor del coeficiente de extinción bacterial es menor que el reportado en la literatura; c No se encontró evidencia que este valor estuviera influido por el número de dispersión de flujo de la laguna.

  18. Macromicetos del Parque Educativo Laguna Bélgica, municipio de Ocozocoautla de Espinosa, Chiapas, México Macrofungi from Parque Educativo Laguna Bélgica, Municipality of Ocozocoautla de Espinosa, Chiapas, Mexico

    Directory of Open Access Journals (Sweden)

    Freddy Chanona-Gómez

    2007-12-01

    Full Text Available El presente estudio tuvo como objetivos contribuir al conocimiento de los macromicetos que crecen en el Parque Educativo Laguna Bélgica (PELB, en Ocozocoautla de Espinosa, Chiapas y determinar el índice de diversidad de Simpson y similitud de Sorensen de la micobiota existente en los diferentes tipos de vegetación. Se realizaron 24 exploraciones micológicas durante un año, encontrándose 144 especies (24 Ascomycota y 120 Basidiomycota. El índice de diversidad, mostró que la vegetación con la micobiota más diversa fue la del bosque de Quercus elliptica (D= 0.9678 la cual presentó mayor similitud con el bosque de Liquidambar stracyflua (Is= 83 %. El sustrato más frecuente fue la madera en descomposición (57.63 %. Se determinaron las especies de macromicetos potencialmente utilizables para el consumo humano (22 especies, lo que determinó el valor micológico del área de estudio en 15.27 %. Del total de especies determinadas 22 son nuevos registros para el estado de Chiapas; 4 Ascomicetos Scutellinia scutellata, Xylaria amphitele, X. persicaria, Chlorociboria aeruginosa, y 18 Basidiomicetos Amanita pantherina, Geastrum striatum, Hydnum repandum, Hygrocybe miniata, Scleroderma verrucosum, Cotylidia diaphana, Lactarius indigo, Phlogiotis helvelloides, Hydnochaete olivaceae, Phellinus ferruginosus, P. contiguus, P.rufitinctus, Thelephora terrestris, T. cervicornis, Perenniporia ohiensis, Diplomitoporus lenis, Schizopora paradoxa y Tremella fuciformis.The objectives of this study were to contribute to the knowledge of macro fungi growing in the "Parque Educativo Laguna Belgica" (PELB, in Chiapas, Mexico and to determine the diversity and similarity indexes for its mycobiota in each type of vegetation. Twenty four mycological explorations were made during a year, resulting in the identification of 144 species (24 Ascomycota and 120 Basidiomycota. The diversity of fungal species was determined through the index of Simpson and the similarity

  19. Preliminary analysis of an hydrogen generator system based on nuclear energy in the Laguna Verde site; Analisis preliminar de un sistema generador de hidrogeno basado en energia nuclear en el sitio de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Flores y Flores, A. [FI-UNAM, 04500 Mexico D.F. (Mexico); Francois L, J.L. [FI-UNAM, Jiutepec, Morelos (Mexico)]. e-mail: alain_fyf@yahoo.com

    2003-07-01

    The shortage of fossil fuels in the next future, as well as the growing one demand of energetics and the high cost of the production of alternating fuels, it forces us to take advantage of to the maximum the fossil fuel with the one which we count and to look for the form of producing alternating fuels at a low cost and better even if these supply sources are reliable and non pollutants. It is intended a solution to the shortage of fuel; to use the thermal energy liberated of some appropriate nuclear reactor to be able to obtain a fuel but clean and relatively cheap as it is the hydrogen. In the first place the methods were looked for to produce hydrogen using thermal energy, later it was analyzed the temperature liberated by the existent nuclear reactors as well as the advanced designs, according to this liberated temperature settled down that the methods but feasible to produce hydrogen its were the one of reformed with water stream of the natural gas (methane) and the other one of the S-I thermochemical cycle, and the nuclear reactors that give the thermal energy for this production they are those of gas of high temperature. Once established the processes and the appropriate reactors, it was analyzed the site of Laguna Verde, with relationship to the free space to be able to place the reactor and the plant producer of hydrogen, as well as the direction in which blow the dominant winds and the near towns to the place, it was carried out an analysis of some explosion of tanks that could store hydrogen and the damage that its could to cause depending from the distance to which its were of the fire. Finally it was carried out an evaluation of capital and of operation costs for those two methods of hydrogen production. (Author)

  20. Three stops of fuel reloading with length of less 30 days in the Laguna Verde Central; Tres paradas de recarga de combustible con duracion de menos de 30 dias en la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Lozano L, A. [Comision Federal de Electricidad, Central Laguna Verde, Subgerencia General de Operacion Planeacion, Veracruz (Mexico)]. e-mail: agustin.lozano@cfe.gob.mx

    2007-07-01

    The Laguna Verde Central having established as mission 'With maximum priority in the safety, to generate electricity by nuclear means with quality and cost competitive, sustained in our personnel's continuous overcoming and deep respect to the environment' and respecting our values (safety, responsibility by results, professional integrity, continuous improving, team working, excellence in the acting, quality of service, protection to the environment) they thought about our strategic objectives of the power station being born this way one of them that it is the program of improvement 'Reduction of reload times' looking for to be improves every day comparing us with the best plants in the world efficient all the processes in the power station that allowed us to measure our acting with the same parameters that settle down at international level like they are nuclear safety, industrial safety, radiological safety, capacity factor, readiness factor, cleaning of the power station attachment to procedures, attention to the detail and certainly to be competitive in the economic aspect. After analyzing the acting record of the power station, evaluating our technical capacity, economic, the location of the installation besides revising the international experiences it was defined that one of the concepts that impact considerably so much to the capacity and readiness factors besides the dose and production cost is the duration of the reload periods, for this reason they were elaborated work strategies to be able to reach our goal of reload days considered in being able to carry out them in less than 30 days, here the actions carried out that they made us complete the three last reloads in less than 30 days are captured. (Author)

  1. Four stops of fuel reloading with duration of less of 30 days in the Laguna Verde Central; Cuatro paradas de recarga de combustible con duracion de menos de 30 dias en la central laguna verde

    Energy Technology Data Exchange (ETDEWEB)

    Lozano L, A. [CFE, Central Laguna Verde, Planeacion, Veracruz (Mexico)]. e-mail: agustin.lozano@cfe.gob.mx

    2008-07-01

    The Laguna Verde Central having established as mission 'With maximum priority in the safety, to generate electricity by nuclear means with competitive quality and cost, sustained in our personnel's continuous overcoming and deep respect to the environment' and respecting our values (safety, responsibility by results, professional integrity, continuous improvement, team work, excellence in the performance, quality of service, protection to the environment its thought about our strategic objectives of the power station being born by this way one of them that it is the improvement program 'reduction of reloading times' looking for to be improves every day comparing us with the best plants of the world effectiveness all the processes in the power station that allowed us to measure our performance with the same parameters that settle down at international level as its are nuclear safety, industrial safety, radiological safety, capacity factor, readiness factor, cleaning of the power station attachment to procedures, attention to the detail and certainly to be competitive in the economic aspect. After analyzing the performance record of the power station, evaluating our technical, economic capacity, the location of the installation besides revising the international experiences was defined that one of the concepts that impact considerably so much to the capacity factors and readiness besides the dose and production cost is the duration of the reloading periods, for this reason work strategies were elaborated to be able to reach our goals of reloading days in less than 30 days, here are formed the carried out actions that they made us complete the four last reloading in less than 30 days. (Author)

  2. Technical and economic proposal for the extension of the Laguna Verde Nuclear Power plant with an additional nuclear reactor; Propuesta tecnica y economica para la ampliacion de la Central Nucleoelectrica Laguna Verde con un reactor nuclear adicional

    Energy Technology Data Exchange (ETDEWEB)

    Leal C, C.D.; Francois L, J.L. [Facultad de Ingenieria, UNAM, Circuito Interior, C.U. Coyoacan, 04510 Mexico D.F. (Mexico)]. e-mail: carlosdanielleal@yahoo.com.mx

    2006-07-01

    The increment of the human activities in the industrial environments and of generation of electric power, through it burns it of fossil fuels, has brought as consequence an increase in the atmospheric concentrations of the calls greenhouse effect gases and, these in turn, serious repercussions about the environment and the quality of the alive beings life. The recent concern for the environment has provoked that industrialized countries and not industrialized carry out international agreements to mitigate the emission from these gases to the atmosphere. Our country, like part of the international community, not is exempt of this problem for what is necessary that programs begin guided toward the preservation of the environment. As for the electric power generation, it is indispensable to diversify the sources of primary energy; first, to knock down the dependence of the hydrocarbons and, second, to reduce the emission of polluting gases to the atmosphere. In this item, the nucleo electric energy not only has proven to be safe and competitive technical and economically, able to generate big quantities of electric power with a high plant factor and a considerable cost, but rather also, it is one of the energy sources that less pollutants it emits to the atmosphere. The main object of this work is to carry out a technical and economic proposal of the extension of the Laguna Verde Nuclear power plant (CNLV) with a new nuclear reactor of type A BWR (Advanced Boiling Water Reactor), evolutionary design of the BWR technology to which belong the two reactors installed at the moment in the plant, with the purpose of increasing the installed capacity of generation of the CNLV and of the Federal Commission of Electricity (CFE) with foundation in the sustainable development and guaranteeing the protection of the environment by means of the exploitation of a clean and sure technology that counts at the moment with around 12,000 year-reactor of operational experience in more of

  3. Study of environmental noise in a BWR plant like the Nuclear Power Plant Laguna Verde; Estudio de ruido ambiental en una planta BWR como la Central Nuclear Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Tijerina S, F.; Cruz G, M.; Amador C, C., E-mail: francisco.tijerina@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Subgerencia de Ingenieria, Carretera Cardel-Nautla Km. 42.5, Alto Lucero, Veracruz (Mexico)

    2013-10-15

    In all industry type the health costs generated by the noise are high, because the noise can cause nuisance and to harm the capacity to work when causing tension and to perturb the concentration, and in more severe cases to reach to lose the sense of the hearing in the long term. The noise levels in the industry have been designated for the different types of use like residential, commercial, and industrial and silence areas. The noise can cause accidents when obstructing the communications and alarm signs. For this reason the noise should be controlled and mitigated, at a low level as reasonably is possible, taking into account that the noise is an acoustic contamination. The present study determines a bases line of the environmental noise levels in a nuclear power plant BWR-5 as Laguna Verde, (like reference) to be able to determine and to give pursuit to the possible solutions to eliminate or to limit the noise level in the different job areas. The noise levels were registered with a meter of integrative noise level (sonometer) and areas of noise exposure levels mapping the general areas in the buildings were established, being the registered maximum level of 96.94 dba in the building of the Reactor-elevation 0.65 m under the operation conditions of Extended Power Up rate (EPU) of 120% PTN. Knowing that the exposition to noises and the noise dose in the job place can influence in the health and in the safety of the workers, are extensive topics that they should be analyzed for separate as they are: to) the effects in the health of the exposure to the noise, b) how measuring the noise, c) the methods and technologies to combat and to control the noise in the industry by part of engineering area and d) the function of the industrial safety bodies as delegates of the health and safety in the task against the noise in the job. (author)

  4. Simulation of overpressure events with a Laguna Verde model for the RELAP code to conditions of extended power up rate; Simulacion de eventos de sobrepresion con un modelo de Laguna Verde para el codigo RELAP a condiciones de aumento de potencia extendido

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez H, A.; Araiza M, E.; Fuentes M, L.; Ortiz V, J., E-mail: andres.rodriguez@inin.gob.mx [ININ, Departamento de Sistemas Nucleares, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2012-10-15

    In this work the main results of the simulation of overpressure events are presented using a model of the nuclear power plant of Laguna Verde developed for the RELAP/SCDAPSIM code. As starting point we have the conformation of a Laguna Verde model that represents a stationary state to similar conditions to the operation of the power station with Extended Power Up rate (EPU). The transitory of simulated pressure are compared with those documented in the Final Safety Analysis Report of Laguna Verde (FSAR). The results of the turbine shot transitory with and without by-pass of the main turbine are showed, and the event of closes of all the valves of main vapor isolation. A preliminary simulation was made and with base in the results some adjustments were made for the operation with EPU, taking into account the Operation Technical Specifications of the power station. The results of the final simulations were compared and analyzed with the content in the FSAR. The response of the power station to the transitory, reflected in the model for RELAP, was satisfactory. Finally, comments about the improvement of the model are included, for example, the response time of the protection and mitigation systems of the power station. (Author)

  5. Cambios en el régimen hídrico de la laguna Lasuntay y Chuspicocha por variaciones en el Nevado Huaytapallana

    Directory of Open Access Journals (Sweden)

    Jacinto Arroyo Aliaga

    2011-12-01

    Full Text Available Objetivos: Estimar los efectos de las variaciones de torrentes de agua de los glaciares del Nevado Huaytapallana que emanan al sistema hídrico de las lagunas de Lasuntay y Chuspicocha. Métodos: Se utilizó el método general teórico deductivo de nivel explicativo, con un diseño no experimental del tipo transversal en el tratamiento de información; como método específico se ha utilizado el balance de masa del glaciar para el cálculo de volúmenes de agua de los torrentes a partir de la instalación de una red de balizas en la mayor parte del glaciar y en la zona de acumulación y ablación se excavaron pozos mediante perforaciones para medir directamente la cantidad de nieve acumulada entre el inicio y el fin del año hidrológico. Resultados: Se ha estimado los torrentes de caudal de agua que emanan del nevado Huaytapallana a las lagunas de Lasuntay y Chuspicocha en 1 226 700 m3 en la estación de verano; y de 245 340 m3 en la estación de primavera. Conclusiones: El volumen máximo de acumulación en ambas lagunas fue en el verano y el volumen mínimo en la estación de primavera, debido a las variaciones en el régimen hídrico del sistema de acumulación y ablación que afectan la disponibilidad de agua.

  6. Paleoecología del último interglacial (EEMIAN y su relación con la vegetación actual en la Laguna De Fúquene (Cundinamarca, Colombia

    Directory of Open Access Journals (Sweden)

    Rangel-Ch J. Orlando

    2006-12-01

    Full Text Available El análisis paleoecológico: polen, sedimentología, granulometría (Grain Size y análisis del contenido de materia
    orgánica por pérdidas por ignición (LOI, realizado en la sección 4.730-5.778 cm pozos Fúquene 9-10 en la laguna de Fúquene (5º28’12” de la latitud N y 73º44’14” de longitud W, localizada a 2.580 m en la cordillera Oriental, muestra un registro de los cambios climáticos y de vegetación del último ciclo glacial-interglacial.
    Se presentó un periodo prolongado de condiciones frías y húmedas (zonas 2, 3 y 4 dominado por pajonales
    de Poaceae y matorrales de especies de Asteraceae e Hypericum, con niveles de la laguna relativamente altos;
    y un periodo cálido y seco (zona 5 dominado por bosques de Myrica y Weinmannia, bosques de Quercus y
    niveles bajos de la laguna. Las zonas 2, 3 y 4 corresponden al estadio isotópico MIS-6 (190.000-130.000 años
    A.P. que comprende el penúltimo glacial con correspondencia al interestadial Muisca, al estadial río Frío y al interestadial Chía. La zona 5 corresponde al inicio del último interglacial MIS-5e Eemian (130.000-120.000
    años A.P. con correspondencia al interglacial Paloblanco temprano. Los resultados obtenidos de la reconstrucción
    paleoecológica fueron comparados con el registro palinológico del último máximo glacial y el actual interglacial Holoceno pozo Fúquene -2.

  7. Summer feeding ecology of Great Pampa-finches, Embernagra platensis at Laguna de Guaminí, Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Laura M. Ferman

    2010-09-01

    Full Text Available The aim of this study was to assemble data on the summer feeding ecology of the Great Pampa-finch, Embernagra platensis at the Laguna de Guaminí, Buenos Aires, Argentina, and to explore the differences related to the dietary patterns for each sex between winter and summer when possible. The stomach contents of 43 birds were analyzed. The animal fraction was composed of Hymenoptera (45.1%, Coleoptera (32.4%, Lepidoptera (6.0%, Araneae (5% and Orthoptera (3.2%. The application of the index of relative importance (IRI resulted in 1490.4 for Coleoptera, 428.5 for Hymenoptera and 162.5 for Lepidoptera caterpillars. The vegetal fraction consisted of Triticum aestivum (26.9%, Cyperaceous (25%, Poaceae (Gramineae (19.3% and Panicum sp. (11.2%. The IRI values were 893.8 for Triticum aestivum, 174.5 for Gramineae, 126.5 for Panicum sp. and 112.8 for Scirpus sp. The food niche width was 0.33 for both sexes; the diversity index resulted in 1.06 for females and 1.33 for males and specific diversity ranged from 1.87 to 2.84. A canonical component analysis (CCA was performed on environmental and morphometric variables, and a Monte Carlo test confirmed the canonical correlations. A t-test showed that some birds harmonized with a logarithmic model and some with a geometric curve. During the summer, Embernagra platensis ingests Hymenoptera and Coleoptera more often than seeds, suggesting that two biological mechanisms could be taking place in this bird.O objetivo deste estudo foi reunir dados referentes à ecologia alimentar do Sabiá-do-banhado, Embernagra platensis, na laguna de Guaminí, Buenos Aires, Argentina, e explorar as diferenças relacionadas aos padrões dietéticos para cada sexo entre inverno e verão, quando possível. O conteúdo estomacal de 43 pássaros foi analisado. A fração animal foi composta por Hymenoptera (45,1%, Coleoptera (32,4%, Lepidoptera(6,0%, Araneae (5% e Orthoptera (3,2%. A aplicação do índice de importância relativa (IRI

  8. Hydrologic, water-quality, and biological assessment of Laguna de las Salinas, Ponce, Puerto Rico, January 2003-September 2004

    Science.gov (United States)

    Soler-López, Luis R.; Gómez-Gómez, Fernando; Rodríguez-Martínez, Jesús

    2005-01-01

    The Laguna de Las Salinas is a shallow, 35-hectare, hypersaline lagoon (depth less than 1 meter) in the municipio of Ponce, located on the southern coastal plain of Puerto Rico. Hydrologic, water-quality, and biological data in the lagoon were collected between January 2003 and September 2004 to establish baseline conditions. During the study period, rainfall was about 1,130 millimeters, with much of the rain recorded during three distinct intense events. The lagoon is connected to the sea by a shallow, narrow channel. Subtle tidal changes, combined with low rainfall and high evaporation rates, kept the lagoon at salinities above that of the sea throughout most of the study. Water-quality properties measured on-site (temperature, pH, dissolved oxygen, specific conductance, and Secchi disk transparency) exhibited temporal rather than spatial variations and distribution. Although all physical parameters were in compliance with current regulatory standards for Puerto Rico, hyperthermic and hypoxic conditions were recorded during isolated occasions. Nutrient concentrations were relatively low and in compliance with current regulatory standards (less than 5.0 and 1.0 milligrams per liter for total nitrogen and total phosphorus, respectively). The average total nitrogen concentration was 1.9 milligrams per liter and the average total phosphorus concentration was 0.4 milligram per liter. Total organic carbon concentrations ranged from 12.0 to 19.0 milligrams per liter. Chlorophyll a was the predominant form of photosynthetic pigment in the water. The average chlorophyll a concentration was 13.4 micrograms per liter. Chlorophyll b was detected (detection limits 0.10 microgram per liter) only twice during the study. About 90 percent of the primary productivity in the Laguna de Las Salinas was generated by periphyton such as algal mats and macrophytes such as seagrasses. Of the average net productivity of 13.6 grams of oxygen per cubic meter per day derived from the diel

  9. Groundwater flow in a closed basin with a saline shallow lake in a volcanic area: Laguna Tuyajto, northern Chilean Altiplano of the Andes

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, Christian, E-mail: cherrera@ucn.cl [Departamento de Ciencias Geológicas, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile); Centro de Investigación Tecnológica del Agua en el Desierto (CEITSAZA), Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile); Custodio, Emilio [Department of Geo-Engineering, Technical University of Catalonia/Barcelona Tech (UPC), Barcelona (Spain); Chong, Guillermo [Departamento de Ciencias Geológicas, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile); Lambán, Luis Javier [Geological Institute of Spain (IGME), Zaragoza (Spain); Riquelme, Rodrigo; Wilke, Hans [Departamento de Ciencias Geológicas, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile); Jódar, Jorge [Department of Geo-Engineering, Technical University of Catalonia/Barcelona Tech (UPC), Barcelona (Spain); Urrutia, Javier; Urqueta, Harry [Departamento de Ciencias Geológicas, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile); Centro de Investigación Tecnológica del Agua en el Desierto (CEITSAZA), Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile); Sarmiento, Alvaro [Departamento de Ciencias Geológicas, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile); and others

    2016-01-15

    Laguna Tuyajto is a small, shallow saline water lake in the Andean Altiplano of northern Chile. In the eastern side it is fed by springs that discharge groundwater of the nearby volcanic aquifers. The area is arid: rainfall does not exceed 200 mm/year in the rainiest parts. The stable isotopic content of spring water shows that the recharge is originated mainly from winter rain, snow melt, and to a lesser extent from some short and intense sporadic rainfall events. Most of the spring water outflowing in the northern side of Laguna Tuyajto is recharged in the Tuyajto volcano. Most of the spring water in the eastern side and groundwater are recharged at higher elevations, in the rims of the nearby endorheic basins of Pampa Colorada and Pampa Las Tecas to the East. The presence of tritium in some deep wells in Pampa Colorada and Pampa Las Tecas indicates recent recharge. Gas emission in recent volcanoes increase the sulfate content of atmospheric deposition and this is reflected in local groundwater. The chemical composition and concentration of spring waters are the result of meteoric water evapo-concentration, water–rock interaction, and mainly the dissolution of old and buried evaporitic deposits. Groundwater flow is mostly shallow due to a low permeability ignimbrite layer of regional extent, which also hinders brine spreading below and around the lake. High deep temperatures near the recent Tuyajto volcano explain the high dissolved silica contents and the δ{sup 18}O shift to heavier values found in some of the spring waters. Laguna Tuyajto is a terminal lake where salts cumulate, mostly halite, but some brine transfer to the Salar de Aguas Calientes-3 cannot be excluded. The hydrogeological behavior of Laguna Tuyajto constitutes a model to understand the functioning of many other similar basins in other areas in the Andean Altiplano. - Highlights: • Recent volcanism formations play a key role in producing recharge. • Groundwater can flow across local

  10. Salida de campo a la laguna de La Nava (Fuentes de Nava, Palencia) los días 1, 2 y 3 de noviembre de 1952

    OpenAIRE

    Valverde Gómez, José Antonio, 1926-2003

    2008-01-01

    Salida de campo a la laguna de La Nava, en Fuentes de Nava, recorriendo también Grijota y Villamartín de Campos, en la provincia de Palencia, los días 1, 2 y 3 de noviembre de 1952, de la que se anotaron observaciones sobre el pez Carassius sp. (Pez rojo), el reptil Natrix maura (Culebra viperina, llamada Tropidonotus viperinus por el autor), los siguientes anfibios: Pelobates cultripes (Sapo de espuelas) y Pelophylax esculentus (Rana verde europea, llamada Rana sculenta o R.esculenta ridibun...

  11. Cambios en el régimen hídrico de la laguna Lasuntay y Chuspicocha por variaciones en el Nevado Huaytapallana

    OpenAIRE

    Jacinto Arroyo Aliaga; Pedro Gurmendi Párraga

    2011-01-01

    Objetivos: Estimar los efectos de las variaciones de torrentes de agua de los glaciares del Nevado Huaytapallana que emanan al sistema hídrico de las lagunas de Lasuntay y Chuspicocha. Métodos: Se utilizó el método general teórico deductivo de nivel explicativo, con un diseño no experimental del tipo transversal en el tratamiento de información; como método específico se ha utilizado el balance de masa del glaciar para el cálculo de volúmenes de agua de los torrentes a partir de la instalació...

  12. A Case Study of Nearshore Wave Transformation Processes along the Coast of Mexico near the Laguna Verde Nuclear Power Plant Using a Fast Simulation Method

    Directory of Open Access Journals (Sweden)

    Israel-Enrique Herrera-Díaz

    2010-01-01

    numerical method was developed using a split proposed version of the mild-slope equation and solved by an implicit method in a finite volume grid; this technique easily allows model the wave effects caused by the breakwater building in coastal waters, where industrial and other economic activities take place. Controlled case studies have been made and the results match very well with the reference solution. The capability and utility of the model for real coastal areas are illustrated by application to the breakwater of the Laguna Verde Nuclear Power Plant (LVNPP.

  13. Los paisajes físico-geográficos de los manglares de la laguna de la Mancha, Veracruz, México

    OpenAIRE

    2006-01-01

    Los manglares que rodean la laguna de La Mancha en Veracruz, México, en condiciones de adecuada conservación, se caracterizan por la complejidad físico-geográfica de sus paisajes. Este trabajo profundiza en la estructura y composición de los geocomplejos en ese territorio. El empleo de los principios estructuro-genético e histórico-evolutivo permitió el levantamiento, clasificación y cartografía de los paisajes de manglares a escala detallada (1: 25000). Se lograron diferenciar 28 unidades in...

  14. La agricultura familiar de traspatio y los pasos hacia la sustentabilidad: una experiencia en la Laguna de Cajititlán, Jalisco, México

    OpenAIRE

    Roldán Roa, María Elena; Almeida Luján, Elena Catalina; Morales Hernández, Jaime; Alvarado Castro, Eric

    2015-01-01

    En Tlajomulco de Zuñiga, Jalisco, México, la agricultura industrial, el desmesurado crecimiento de la mancha urbana de la Zona Metropolitana de Guadalajara y las descargas de aguas industriales, ponen en riesgo la existencia de la Laguna de Cajititlán y con ello la vida de todos los pobladores ribereños. El equipo del Instituto Tecnológico y Estudios Superiores de Occidente realiza diversas actividades de acompañamiento a las organizaciones locales, en la perspectiva de fortalecer los avances...

  15. Ictiofauna de la laguna de San Ignacio, Baja California Sur, México: nuevos registros y ampliaciones de ámbito

    OpenAIRE

    1998-01-01

    Se actualiza el inventario ictiológico de la Laguna de San Ignacio, Baja California Sur (México), con la adición de 26 especies. Se registra la ampliación de distribución geográfica de ocho especies. En la lista sistemática se aportan datos acerca de las tallas, números de registro en la colección, cantidad de especímenes recolectados y su afinidad ictiogeográfica. La lista actualizada incluye 107 especies, 89 géneros, 54 familias y 21 órdenes.

  16. Estudio de percepción y análisis de evaluación sensorial del mezcal de Laguna Seca

    OpenAIRE

    Andrade Luna, Silvia Aurora

    2016-01-01

    Se analizó un estudio sobre percepción y la evaluación sensorial del mezcal artesanal elaborado en el municipio de Charcas, San Luis Potosí en la Fábrica de mezcal Laguna Seca. La valoración consistió en describir sensorialmente y determinar el nivel de aceptación por un grupo de estudio, con el propósito de generar una base de la calidad sensorial que permita a los productores del mezcal compararlo con otros mezcales. Se tomaron tres mezcales de comparación: mezcal joven, reposado ...

  17. Análisis preliminares de los materiales líticos provenientes de la Laguna Blanca Chica (Olavarría, Buenos Aires)

    OpenAIRE

    Pablo G. Messineo; Lázaro D'Augerot

    2004-01-01

    En este trabajo se presentan los resultados preliminares sobre el estudio de los materiales líticos recuperado en la Laguna Blanca Chica (Partido de Olavarría, Provincia de Buenos Aires). El objetivo principal es conocer las estrategias relacionadas al aprovisionamiento y explotación de las materias primas presentes, como los procesos tecnológicos utilizados sobre las mismas. Los resultados obtenidos indican que la ftanita (55,58%) y la cuarcita (43,23%) fueron las materias primas más utiliza...

  18. Especies fitoplanctónicas formadoras de proliferaciones algales nocivas en la boca de la laguna costera de Sontecomapan, Veracruz, México

    OpenAIRE

    Muciño Márquez, Rocío Elizabeth; Figueroa Torres, María Guadalupe; Gárate Lizárraga, Ismael

    2011-01-01

    En Veracruz, la mortandad de peces debido a la formación de proliferaciones algales nocivas se conoce históricamente desde 1792. Analizamos la distribución y la abundancia de las especies que forman Proliferaciones Algales Nocivas (FAN) a lo largo de un ciclo nictemeral, en la boca de la laguna costera de Sontecomapan, Veracruz, el 27 y 28 de octubre de 1999. Se recolectaron muestras de agua cada dos horas con una botella Van Dorn para medir la temperatura, la salinidad, el pH, el oxígeno dis...

  19. Variación nictemeral del género Prorocentrum (Dinophyceae) en la laguna costera Sontecomapan, Veracruz, México

    OpenAIRE

    MUCIÑO-MÁRQUEZ, Rocio Elizabeth; Figueroa-Torres, Maria Guadalupe; Gárate Lizárraga, Ismael

    2011-01-01

    El género Prorocentrum Ehrenberg, incluye 62 especies marinas, 21 son consideradas formadoras de florecimientos algales nocivos (FAN), de las cuales aproximadamente 10 especies producen toxinas. Considerando lo anterior, el objetivo de este trabajo consistió en determinar la distribución y abundancia de las especies del género Prorocentrum durante un ciclo nictemeral, así como la influencia de algunas variables ambientales, en la boca de la laguna costera de Sontecomapan Veracruz, México. Los...

  20. Análisis prospectivo del conflicto político ambiental, sobre el uso del espacio público Parque La Laguna, localizado en la Urbanización Nueva Casarapa, Estado Miranda.Venezuela

    Directory of Open Access Journals (Sweden)

    Mildred Zerpa

    2013-06-01

    Full Text Available Nueva Casarapa, es un complejo urbanístico integral concebido bajo el concepto de ciudad. Posee espacios abiertos, centros comerciales, espacios verdes y públicos cuidados por los propios habitantes y un parque central conocido como La Laguna. En 2009 comenzó una polémica que podría convertirse en conflicto socio natural con implicaciones en la gestión integral de riesgo del Municipio Plaza, por la incertidumbre acerca de cuál grupo es el más indicado para administrar y gestionar el parque La Laguna.

  1. Fuertes paleosismos de intraplaca y sus retornos vinculados a la falla Las Lagunas, Sierras Pampeanas de Cordoba

    Directory of Open Access Journals (Sweden)

    Guillermo L Sagripanti

    2011-03-01

    Full Text Available En la intraplaca argentina, a la latitud 33°S, región sur de la provincia de Córdoba, la presencia de morfologías superficiales y deformaciones en sedimentos sueltos cuaternarios hacen suponer que la actividad tectónica neógena tuvo continuidad en el Holoceno y que seguramente fue acompañada por la ocurrencia de paleoterremotos. Los objetivos del presente trabajo son, por medio de investigaciones paleosismológicas realizar la reconstrucción del registro de la sismicidad prehistórica de la región y una estimación del potencial sismogénico de una fuente, con probada actividad cuaternaria, que sean de base en la estimación del riesgo sísmico de la región. Se excavaron seis trincheras transversales a la traza de la falla Las Lagunas, en sedimentos de origen eólico, fluvial y lagunar, en las cuales se relevaron estructuras cosísmicas, deformacionales y de licuefacción, de escala mesoscópica. Los resultados obtenidos han permitido proponer un modelo de retrodeformación para la falla, calcular el período de recurrencia de fuertes terremotos que es del orden de 1,2 - 2,0 Ka, calcular la magnitud de algunos paleo-eventos, Ms > 6,6 y hacer una estimación de la magnitud del terremoto máximo.

  2. Local climate change induced by groundwater overexploitation in a high Andean arid watershed, Laguna Lagunillas basin, northern Chile

    Science.gov (United States)

    Scheihing, Konstantin; Tröger, Uwe

    2017-08-01

    The Laguna Lagunillas basin in the arid Andes of northern Chile exhibits a shallow aquifer and is exposed to extreme air temperature variations from 20 to -25 °C. Between 1991 and 2012, groundwater levels in the Pampa Lagunillas aquifer fell from near-surface to 15 m below ground level (bgl) due to severe overexploitation. In the same period, local mean monthly minimum temperatures started a declining trend, dropping by 3-8 °C relative to a nearby reference station. Meanwhile, mean monthly maximum summer temperatures shifted abruptly upwards by 2.7 °C on average in around 1996. The observed air temperature downturns and upturns are in accordance with detected anomalies in land-surface temperature imagery. Two major factors may be causing the local climate change. One is related to a water-table decline below the evaporative energy potential extinction depth of 2 m bgl, which causes an up-heating of the bare soil surface and, in turn, influences the lower atmosphere. At the same time, the removal of near-surface groundwater reduces the thermal conductivity of the upper sedimentary layer, which consequently diminishes the heat exchange between the aquifer (constant heat source of 10 °C) and the lower atmosphere during nights, leading to a severe dropping of minimum air temperatures. The observed critical water-level drawdown was 2-3 m bgl. Future and existing water-production projects in arid high Andean basins with shallow groundwater should avoid a decline of near-surface groundwater below 2 m bgl and take groundwater-climate interactions into account when identifying and monitoring potential environmental impacts.

  3. Reproducción y crecimiento de Heterandria bimaculata (Cyprinodontiformes: Poeciliidae en la Laguna "El Rodeo", Morelos, México

    Directory of Open Access Journals (Sweden)

    José Luis Gómez-Márquez

    1999-09-01

    Full Text Available De diciembre de 1986 a diciembre de 1987 se determinaron algunos aspectos de reproducción y crecimiento de Heterandria bimaculata de la laguna "El Rodeo", Morelos, México. Los resultados obtenidos muestran que de los 1 421 organismos recolectados, el 60.12% corresponden a hembras, el 34.98% a machos y el 4.89% a juveniles; con proporción sexual a favor de las hembras de 1.7: 1 (hembras: machos ;pWe studied reproduction and growth of Heterandria bimaculata in "El Rodeo" lake Morelos, Mexico, from December 1986 through December 1987. A total of 1 452 specimens were obtained (monthly samples. Females represented 60.12 %, males 34.98 % and the young 4.89 % of the population. Overall sex ratio was 1.7: 1 in favor of females (p<0.05. The size at first reproduction for females was 27 mm and for males 22 mm (standard lengths; multiple spawning occured throughout the reproductive cycle (from March through May and July through October primarily, during the rainy season. There was evidence of breeding activity throughout the year. In July the gonadosomatic index mean was highest (4.7%. The number of embryos in the ovaries were between 5 and 78, with a mean fertility of 23, the fertility was associated with standard length with determination coefficients above 93.22 percent. There was a direct relationship between specimen length and weight, and the asymptotic size for males was 64 mm and for females 81 mm (standard lengths.

  4. Preliminary Seismic Velocity Structure Results from Ambient Noise and Teleseismic Tomography: Laguna del Maule Volcanic Field, Chile

    Science.gov (United States)

    Wespestad, C.; Thurber, C. H.; Zeng, X.; Bennington, N. L.; Cardona, C.; Singer, B. S.

    2016-12-01

    Laguna del Maule Volcanic Field is a large, restless, rhyolitic system in the Southern Andes that is being heavily studied through several methods, including seismology, by a collaborative team of research institutions. A temporary array of 52 seismometers from OVDAS (the Southern Andean Volcano Observatory), PASSCAL (Portable Array Seismic Studies of the Continental Lithosphere), and the University of Wisconsin-Madison was used to collect the 1.3 years worth of data for this preliminary study. Ambient noise tomography uses surface wave dispersion data obtained from noise correlation functions (NCFs) between pairs of seismic stations, with one of each pair acting as a virtual source, in order to image the velocity structure in 3-D. NCFs were computed for hour-long time windows, and the final NCFs were obtained with phase-weighted stacking. The Frequency-Time Analysis technique was then utilized to measure group velocity between station pairs. NCFs were also analyzed to detect temporal changes in seismic velocity related to magmatic activity at the volcano. With the surface wave data from ambient noise, our small array aperture limits our modeling to the upper crust, so we employed teleseismic tomography to study deeper structures. For picking teleseismic arrivals, we tested two different correlation and stacking programs, which utilize adaptive stacking and multi-channel cross-correlation, to get relative arrival time data for a set of high quality events. Selected earthquakes were larger than magnitude 5 and between 30 and 95 degrees away from the center of the array. Stations that consistently show late arrivals may have a low velocity body beneath them, more clearly visualized via a 3-D tomographic model. Initial results from the two tomography methods indicate the presence of low-velocity zones at several depths. Better resolved velocity models will be developed as more data are acquired.

  5. Recent nuclear technology advances of GE-H and GNF in partnership with CFE's Laguna Verde 2

    Energy Technology Data Exchange (ETDEWEB)

    Cuevas V, G.; Iwamoto, T.; Banfield, J. [GE-Hitachi Nuclear Energy Americas LLC, Global Nuclear Fuel - Americas LLC, 3901 Castle Hayne Road, Wilmington, 28401 North Carolina (United States); Calleros M, G., E-mail: Gabriel.Cuevas-Vivas@age.com [Comision Federal de Electricidad, Central Nucleoelectrica de Laguna Verde, Carretera Veracruz-Nautla Km 42.5, Alto Lucero, Veracruz (Mexico)

    2015-09-15

    This paper is presented based on work stemming from the long-standing technical partnership between Comision Federal de Electricidad (CFE) and Global Nuclear Fuel - Americas LLC (GNF), and this paper's purpose is to provide valuable information for the nuclear industry. First, a one-to-one comparison of measurements from Gamma Thermometers (G Ts) installed in Laguna Verde 2 (LV-2) core against axially corresponding Traverse In-core Probe (Tip) measurements is remarkably close. This longest running G T plant validation for the Economic Simplified Boiling Water Reactor (ESBWR) power monitoring devices is also proving that the devices have the potential to simplify power measurements in Boiling Water Reactors (BWRs). Second, code validation results show remarkable reduction of radial power uncertainty with respect to current technology when new GNF codes for three-dimensional core simulations are compared to Tip power measurements. The LV-2 core is of paramount importance for BWR data analysis since the core has been loaded from the start of operation with different GNF fuel bundle types, fuel management has been designed with GNF codes and on-line core monitoring has been performed with GNF's 3-Dimensional Monicore system. This validation is also reliable since gamma Tips are used for local power measurements rather than thermal neutron Tips, which are more sensitive to local turbulence and positional changes. A nuclear/thermal-hydraulic core simulation of GNF fuel is undertaken from the beginning of operation of LV-2 (cycle 1) through the range of different power scenarios including low power, original licensed thermal power, power up rate and extended power up rate. Results confirm the conclusions from previous validations in different BWRs and support GNF efforts for licensing the new generation of nuclear engineering codes. (Author)

  6. [Specific diversity and culicidian nuisance in the villages of N'gatty and Allaba in laguna area of Ivory Coast].

    Science.gov (United States)

    Fofana, D; Konan, K L; Djohan, V; Konan, Y L; Koné, A B; Doannio, J M C; N'goran, K E

    2010-12-01

    Entomological surveys were undertaken between June and December 2006 in N'gatty and Allaba. These villages are located in southern Ivory Coast in a laguna area in Dabou department. In these villages, there are large swampy areas, which have caused the multiplication of anthropophilic Culicidae. Mosquitoes have been collected at preimaginal stage at the time of the larval prospecting and at adult stage through human landing catch. Larval collections have been made using the classic method of "dipping". Larvae have been identified to the genus level. Then, they have been bred in the laboratory to identify adults. Adults collection has been made once a month during three consecutive nights by human landing catch inside houses. Adults have been identified to the specific level. Eight genera of mosquitoes have been collected in these two villages: Aedes, Anopheles, Coquillettidia, Culex, Eretmapodites, Mansonia, Toxorhynchites and Uranotaenia. Twenty-four species have been listed during this stu y. The genus Mansonia is the most predominant with 86% (N = 15,811) and 80% (N = 1,385), respectively, in N'gatty and Allaba. The average biting rate per day varies between N'gatty and Allaba. It is estimated to 308 bites per human per night (b/h/n) in N'gatty and 72 b/h/n in Allaba. In these villages, mosquito nuisance is mainly due to Mansonia with 264 b/h/n and 58 b/h/n, respectively, in N'gatty and Allaba. However, Anopheles gambiae s.l. average rate was 12 b/h/n in N'gatty and 2 b/h/n in Allaba.

  7. Training in fundamentals of radiological coverage in Laguna Verde NPP; Entrenamiento de fundamentos de coberturas radiologicas en la CLV

    Energy Technology Data Exchange (ETDEWEB)

    Lara H, M. A., E-mail: marcolarah@gmail.com [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km. 42.5, Alto Lucero, Veracruz (Mexico)

    2014-10-15

    In 2010, the Institute of Nuclear Power Operations (INPO) celebrates the Knowledge Transfer and Retention Workshop, an event where nuclear regulators and operators presented the strategies that various NPP to worldwide were implemented to mitigate the consequences of this generational change and take advantage of it, the trend in the presented works was the same: the generational change occurs in a faster way that the transfer of knowledge, the future was already here and many NPP had not been adequately prepared to train its nuclear technicians and engineers in the tasks demanded by the industry of them, so in addition to preparing these workers to forced marches was necessary to establish strategies to retain at more experienced staff in the industry. The Laguna Verde NPP has not been exempt to this process; the preparation of personnel squares to replace those that reaching retirement age in the Comision Federal de Electricidad (CFE) has become extensive in the last five years, sometimes leading to have personnel covering functions without an alternate to the next lower position, the cause? Not enough staff. In the specific case of radiation protection (Rp) the time required for obtaining the status of Rp technician according to the ANSI/ANS 3.1 standard is 2 years, one of the tasks that most occupies part of these two years is training in radiological coverage, this training requires a mix of knowledge and experience, recently one of the concepts used for training in Rp is the evaluation and management of the radiological risk, topic that is considered in this technical work. (Author)

  8. COMUNIDADES DE PLANTAS ACUÁTICAS EN LAGUNAS DE LOS PÁRAMOS DEL NORTE Y SUR DEL ECUADOR

    Directory of Open Access Journals (Sweden)

    TERNEUS ESTEBAN

    2002-12-01

    Full Text Available Se analiza la distribución de plantas acuáticas y sus relaciones con factores ambientalesen 16 lagunas andinas (3100–3900 m snm, nueve ubicadas cerca a la fronteranorte del Ecuador, y siete ubicadas 600 km hacia el sur de las primeras, en el ParqueNacional Podocarpus. El propósito del estudio es identificar diferencias en la composiciónflorística y factores ambientales de dos sistemas lacustres ubicados enformaciones geológicas distintas y que por su distancia geográfica podrían serdistintos. La similitud florística se analizó mediante el índice de Steinhaus, mientrasque las similitudes ambientales fueron analizadas mediante la distancia euclidiana.La incidencia de la altitud, la temperatura del agua, el pH, la conductividad, el tipo desustrato, el contenido de SO4 y de macronutrientes (Ca, Na, K, Al, Fe, Pb se determinópor medio del Análisis de Componentes Principales (PCA. Se encontraron 19especies en total (16 en los páramos de El Ángel y nueve en los páramos del ParqueNacional Podocarpus, de las cuales seis fueron comunes a las dos áreas de estudio.La riqueza de especies cerca de las orillas fue mayor que en las zonas profundas (>1m. Las plantas enraizadas sumergidas fueron el modo de vida más diverso (47%,seguidas por las enraizadas flotantes (21% y enraizadas emergentes (21%. Lasplantas libre-flotantes (11% fueron las más pobres en especies. El tipo de sustratoy la concentración de SO4 fueron los parámetros ambientales que explicaron mejorlos cambios en la composición florística, mientras que el pH, la altitud y la temperaturadel agua tuvieron menos impacto.

  9. Características bio-ópticas y morfometría de una laguna de zona templada

    Directory of Open Access Journals (Sweden)

    Yael Bohn, Vanesa

    2013-06-01

    Full Text Available The aim of this study was to evaluate the correlation between field sensors and sate - llite images in the bio-optical characterization of Lake Chasicó (Argentina during the February-April 2010 period. The morphometric parameters of the body of water were obtained from in situ measurements and satellite data processing. The sensors that were used allowed spectral signatures to be acquired and then surface water characteristics were detected: turbidity, chlorophyll-a and depth variations. Results obtained from the morphometric analysis included that the lake surpassed the 50 km2 extension and showed a sub-rectangular elongated shape. The chlorophyll-a spatial distribution in the lake was modeled from the satellite image processing, in situ chlorophyll-a data and the Normalized Difference Vegetation Index (NDVI calculation. 53.2 % of its area showed a chlorophyll-a range between 5 and 10 g/l. Therefore, the body of water was characterized as a mesotrophic lake, during the studied period.El objetivo de este trabajo fue evaluar la correlación entre sensores de campo e imágenes satelitales en la caracterización bio-óptica de la laguna Chasicó (Argentina en el período febrero-abril de 2010. Los parámetros morfométricos del cuerpo de agua se obtuvieron a partir de mediciones in situ y datos satelitales. Los sensores empleados permitieron la adquisición de firmas espectrales en las que se detectaron algunas características del agua superficial: turbidez, clorofila «a» y variaciones de profundidad. Como resultado del análisis morfométrico, se obtuvo que la laguna superó los 50 km2 de extensión y presentó una forma subrectangular elongada. A partir del procesamiento de imágenes satelitales, datos de clorofila «a» y el cálculo del Índice de Vegetación de Diferencia Normalizada (en inglés, NDVI, se modeló la distribución espacial del pigmento en la laguna. El 53,2% de su área presentó entre 5 y 10 μg/l de clorofila «a», por

  10. Radiological analysis by the addition of hydrogen and noble metals in the reactors of the Laguna Verde central; Analisis radiologico por la adicion de hidrogeno y metales nobles en los reactores de la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Padilla C, I. [CFE, Proteccion Radiologica (Mexico)]. e-mail: ipadilla@cfe.gob.mx

    2006-07-01

    and of the radiological behavior when applying them, its allowed to settle down strategies in the Laguna Verde Central to control and to reduce the magnitude of the radiological increment in the primary steam lines in both units during the initial period of application. The radiological effects by the addition of hydrogen and of the noble metals, and its incorporation sequence to the reactor are the one reason of this work. (Author)

  11. Cause-Effect relationship of the Laguna Verde BWR power instability by empirical mode decomposition; Relacion efecto-causa de la inestabilidad de potencia del BWR de Laguna Verde por descomposicion modal empirica

    Energy Technology Data Exchange (ETDEWEB)

    Blazquez, J.; Ruiz, J.; Castillo, R. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)

    2008-07-01

    The signals coming from natural phenomena are in essence non lineal and not stationary. A recent development, well-known as Empirical Mode Decomposition (EMD) it presents a novel focus that allows to represent in adaptative form non stationary signals as a sum of components of half zero. These components denominated Intrinsic Mode Functions (IMF) they help to the analysis of the frequency composition of unidimensional signals. The use of the EMD followed by the Hilbert transform of the IMFs it allows to carry out an analysis in time-frequency of the non lineal and not stationary data. This technique is known as the Hilbert Huang Transform (HHT). In this work a power instability event occurred in January 24, 1995 in the unit I of the nuclear power station of Laguna Verde (Mexico), corresponding to a BWR/5 is analyzed. When a Nuclear Plant suffers a power instability event, it is required obligatorily to explain to the Regulator Organism the effects and the causes of the event. The effects are described simply; not in vain there is a registration of signals in the Process Computer of where the required information is extracted. But the causes are not always immediate and easy for to identify. The power instability can happen during the start, when the refrigeration flow is relatively low in front to the power. By reason of that the reactivity coefficient by holes is negative, the power oscillates with a very defined frequency, generally of the order of 0.5 Hz. If the oscillations increase progressively of amplitude, we are in an instability event. It is interesting to include in the report the instant in that the began instability and the actions of the operator before and after the same one. As the actions are registered, the investigation is focused toward the instant of the beginning to be able to identify them. In this work the power signal in five empiric ways of Hilbert-Huang and a residual breaks down. The instability is only reflected in the way of smaller

  12. Metodología para la selección del régimen de flujo en lagunas de estabilización

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Cruz T.

    2011-02-01

    Full Text Available Para modelar procesos biológicos, se necesita información sobre la estequiometría y cinética de las reacciones y sobre el régimen hidráulico del sistema. La estequiometría de una reacción se refiere a la cantidad de reactantes consumidos (tales como sustratos, y a la cantidad de productos formados (tales como microorganismos. El régimen hidráulico hace referencia a la configuración del flujo dentro y fuera del proceso y a la mezcla y distribución de los sólidos del fluido dentro del reactor. El presente artículo se centrará en estudiar los diferentes regímenes de mezcla y sus modelos cinéticos de degradación de materia orgánica aplicados al caso específico de la laguna de estabilización de aguas residuales del municipio de Tocancipá. Además se discute la metodología para determinar el tipo de flujo que sepresenta en una laguna de estabilización.

  13. REGISTROS NUEVOS O POCO CONOCIDOS DE AVES MIGRATORIAS EN LA LAGUNA DEL OTÚN, PARQUE NACIONAL NATURAL LOS NEVADOS, RISARALDA, COLOMBIA

    Directory of Open Access Journals (Sweden)

    ORLANDO ACEVEDO-CHARRY

    2013-01-01

    Full Text Available Colombia es un sitio importante para las aves migratorias. Sin embargo, aún falta mucho conocimiento de dónde estas se encuentran durante su paso o permanencia por el país y cuáles utilizan los páramos. Registramos nuevas especies de aves migratorias para la laguna del Otún, inmersa en un complejo de humedales declarados sitio Ramsar desde el 2008. La laguna está localizada en el Parque Nacional Natural Los Nevados a 3932 msnm, en ecosistema de páramo, en la Cordillera Central de los Andes de Colombia. Durante cinco salidas entre 2010 y 2012 se registraron cuatro nuevas especies de aves migratorias para el parque: Anas acuta, Pandion haliaetus, Riparia riparia y Dendroica petechia. Adicionalmente, se registró una ampliación del rango altitudinal para dos especies mi- gratorias que solo habían sido registradas en la región a menos de 3500 msnm: Tringa flavipes e Hirundo rustica. Estas observaciones sugieren que dichas especies podrían tolerar condiciones de alta montaña y utilizar el páramo. Es necesario estudiar a fondo las diná- micas migratorias y el uso de hábitat de alta montaña por las aves migratorias.

  14. Variaciones y características en los cambios de nivel de la laguna cratérica del Volcan Irazú (1965-2012, Costa Rica

    Directory of Open Access Journals (Sweden)

    Ronald Ramírez

    2013-06-01

    Full Text Available La laguna cratérica del Irazú ha presentado cambios notorios en su coloración, temperatura, grado de acidez y profundidad desde 1965 hasta 2012. El nivel ha variado desde los 31 m en 1995 y 2001 hasta quedarse totalmente seca como sucedió principalmente en 1977, 1979, 1982-83, 1987 y 1990. Estos niveles no siempre se encuentran relacionados en forma directa con el grado de precipitación pluvial. En ciertos momentos, al parecer, en el fondo impermeabilizado de la laguna, se forman grietas que permiten drenar relativamente rápido, dejando el fondo visible por varios meses o años, para que tiempo después se vuelva a formar debido a una nueva selladura de las mismas. La variación del color (verde, turquesa azulado a amarillo, más raramente blanquecino y rojizo en las periferias, temperatura (16º-35ºC, pH (2,85-5,85 parece estar relacionada con la profundidad, actividad de fumarolas subacuáticas, actividad de algas y a la formación de sedimentos ferruginosos producto de los constantes deslizamientos de las paredes.

  15. Estudio de viabilidad de recarga artificial del acuifero - que alimenta la laguna del senor, en la Comarca del Carracillo, Segovia, España

    Directory of Open Access Journals (Sweden)

    Cubero, J.

    2002-04-01

    Full Text Available The Carracillo District in North of the Segovia province belongs to the Quaternary sandbanks located at the South of the Duero river. It constitutes an extensive plain, where the main natural, geologic and geomorphologic elements are wetlands related to the discharge of underground waters. In the last years the intensive exploitation of the aquifers, especially the surficral quatern. a ry .t riggered important descents of the levels that caused the drying of important wetland. In this work, we propose to certificially recharge a specific wetland (Laguna del Señor.La Comarca del Carracillo se encuentra en el Norte de la provincia de Segovia, asentada sobre los arenales cuaternarios situados al Sur del río Duero. Constituye una extensa planicie, donde los principales elementos naturales, geológicos o geomorfológicos son zonas de encharcamiento relacionadas a la descarga de aguas subterráneas. En los últimos años la explotación intensiva de los acuíferos, en especial del cuaternario superficial, provocaron grandes descensos de los niveles que trajo aparejada la desecación progresiva de importantes humedales. En el presente trabajo se plantea la posibilidad de realizar una recarga artificial a un humedal específico (Laguna del Señor.

  16. El registro de la pequena edad de hielo en lagunas pampeanas The record of the Little Ice Age in the Pampean lakes

    Directory of Open Access Journals (Sweden)

    Cecilia Laprida

    2009-12-01

    Full Text Available Se conoce como Pequeña Edad de Hielo (LIA al episodio acontecido entre el siglo 16 y mediados del siglo 19, durante el cual el clima en Europa se tornó frío y ocasionalmente tormentoso. En ciertas partes de Europa, las observaciones instrumentales lo abarcan parcialmente, pero para Sudamérica no se dispone de registros instrumentales contemporáneos a dicho evento. Con el objetivo de obtener nuevas evidencias para el período comprendido por la Pequeña Edad de Hielo en la llanura pampeana, se analizaron testigos cortos de la laguna de Chascomús y de la laguna del Monte los que, de acuerdo a dataciones AMS, abarcan los últimos 500 años. Ambos testigos constan de tres secuencias granodecrecientes. El análisis del registro de la laguna de Chascomús ha permitido reconocer un período benigno desde fines del siglo 15 hasta alrededor del 1700, cuando se evidencia una retracción de la laguna que inaugura un período seco. Este episodio habría continuado por casi 150 años y se revierte alrededor de 1850, momento a partir del cual los eventos de excesos hídricos comenzaron a dominar el escenario pampeano. La base del testigo de la laguna de Monte fue datada en 1441-1494 AD. Si bien el modelo de edades para este testigo aún no ha podido ser bien establecido, los eventos de Chascomús y Monte podrían ser correlacionables y expresar tendencias seculares regionales de la humedad.The Little Ice Age (LIA is a climate episode between the 16th and middle 19th centuries, characterized in Europe by colder temperatures and occasionally stormy weather. In certain areas of Europe, long instrumental observations record the Little Ice Age partially; however, in the pampean region meteorological data only started about one hundred years ago. The objective of this contribution is to provide new evidences about the Little Ice Age in the Pampean plain based on lake cores. Short cores of Chascomús and Monte lakes were analyzed and, according to AMS data

  17. Technical assistance in relationship with the reloading analysis of the Laguna Verde Unit 2 reactor. Executive abstract; Asistencia tecnica en relacion con el analisis de recargas de la CNLV U-2

    Energy Technology Data Exchange (ETDEWEB)

    Alonso V, G.; Castro B, M.; Gallegos E, R.; Hernandez L, H.; Montes T, J.L.; Ortiz S, J. J.; Perusquia C, R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1993-11-15

    The objective of the report was to carry out a comparative analysis of costs of energy generation among the designs GE9B of General Electric, 9X9-IX of SIEMENS and SVEA-96 of ABB ATOM, proposed to be used as recharge fuel in the Unit 2 of the Laguna Verde Nuclear Power station. (Author)

  18. Simulation of an operation cycle of nuclear power plant of Laguna Verde with code TACHY and computation package CMS; Simulacion de un ciclo de operacion de la CNLV con el codigo TACHY y el paquete de computo CMS

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J. A.; Del Valle, E.; Vargas, S.; Xolocostli, J. V. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)], e-mail: joseangel.gonzalez@inin.gob.mx

    2009-10-15

    In this work the code TACHY is used, to simulate an operation cycle of the nuclear power plant of Laguna Verde. The code TACHY was designed originally to analyze recharge patterns of Hindu plants type BWR, that have near 800 assemblies, that is almost double the reactor of nuclear power plant of Laguna Verde. For this reason it was necessary to modify the code to be able to apply it to nuclear power plant of Laguna Verde. The values were modified like: operation power, entrance subcooling, flow through the nucleus, assemblies number in nucleus and dimensions of nucleus. In this work is take like base the cycle 9 of Unit 2 of nuclear power plant of Laguna Verde. This cycle is simulated with code TACHY and with code SIMULATE-3 that is part of computation package Core Management System, with the purpose of comparing the results. The results that are compared with the two codes, for the complete nucleus are: the burnt average of nucleus, the cycle longitude, the effective factor of neutrons multiplication, the pick of radial relative power; and for each assembly: the burnt and the relative power. Of the results obtained with TACHY we can conclude that we have a computation tool that allows to analyze a great number of recharge patterns in a reasonable time. (Author)

  19. CARACTERIZACIÓN ESTRUCTURAL DEL MANGLAR EN EL ESTERO PALO VERDE, LAGUNA DE CUYUTLÁN, COLIMA

    Directory of Open Access Journals (Sweden)

    Citlalli P. Téllez-García

    2012-01-01

    Full Text Available En el Estero Palo Verde, ubicado en el vaso IV de la Laguna de Cuyutlán, estado de Colima, se establecieron 48 unidades de muestreo (UM en tres rodales de mangle: 10 UM en rodal monoespecífico de Laguncularia racemosa, 25 UM en rodal monoespecífico de Rhizophora mangle y 13 UM en rodal mixto de L. racemosa-R. mangle. Se registró altura del dosel, diámetro del tronco, densidad de adultos y de repoblación, también se calculó área basal y volumen de madera. Los resultados indicaron que la densidad, área basal y volumen, para la categoría diamétrica (CD de 5 cm fueron significativamente diferentes (P < 0.05 entre los rodales monoespecíficos de R. mangle (2,500 árboles•ha-1, 4.2 m2•ha-1 y 22 m3•ha-1, respectivamente y L. racemosa (700 árboles•ha-1, 1.9 m2•ha-1 y 10 m3•ha-1, respectivamente. En las CD de 20 a 30 cm, el área basal fue significativamente mayor (P < 0.05 en el rodal monoespecífico de L. racemosa (1.6 - 3.8 m2•ha-1 que en el mixto de L. racemosa-R. mangle (0.5 - 2.5 m2•ha-1. La repoblación natural fue más abundante en el rodal de R. mangle (138 a 270 individuos•ha-1 que en el de L. racemosa (70 a 80 individuos•ha-1. Los valores estructurales mayores se alcanzaron para altura del dosel (10 m en el rodal de L. racemosa; para diámetro (40 cm y área basal (14.1 m2•ha-1 en el rodal de L. racemosa-R. mangle; y para repoblación natural (624 individuos•ha-1 en el rodal de R. mangle.

  20. Crustal deformation and magmatic processes at Laguna del Maule volcanic field (Chile): Geodetic measurements and numerical models

    Science.gov (United States)

    Le Mével, Hélène

    The Laguna del Maule (LdM) volcanic field in Chile is an exceptional example of postglacial rhyolitic volcanism in the Southern Volcanic Zone of the Andes. Since 2007, LdM has experienced an unrest episode characterized by high rates of deformation measured by interferometric analysis of synthetic aperture radar (SAR) images acquired between 2007 and 2016, and data from the Global Positioning System (GPS) recorded since 2012 at five stations. The inflating region includes most of the 16--km-by--14--km ring of rhyolitic domes and coulees. The fastest-moving GPS station (MAU2) has a velocity vector of [[special character omited]72 +/- 4, 19 +/- 1, 194 +/- 3] mm/yr between 2012 and 2016 for the eastward, northward, and upward components, respectively. First, we model the InSAR observations assuming a rectangular dislocation in a half space with uniform elastic properties. The best time function for modeling the InSAR data set is a double exponential model with rates increasing from 2007 through 2010 and decreasing slowly since 2011. Modeling of historical uplift at Yellowstone, Long Valley, and Three Sisters volcanic fields suggests a common temporal evolution of vertical displacement rates. We hypothesize that magma intruding into an existing silicic magma reservoir is driving the surface deformation and present a new dynamic model to describe this process. A Newtonian fluid characterized by its viscosity, density, and pressure flows through a vertical conduit, intruding into a reservoir embedded in an elastic domain and leading to time-dependent surface deformation. Using a grid-search optimization, we minimize the misfit to the InSAR displacement data by varying the three parameters governing the analytical solution: the characteristic timescale tauP for magma propagation, the injection pressure, and the inflection time when the acceleration switches from positive to negative. For a spheroid with semi-major axis a = 6200 m, semi-minor axis c = 100 m, located at a

  1. La docencia del área de Toxicología de la Universidad de La Laguna

    Directory of Open Access Journals (Sweden)

    A. J. Gutiérrez Fernández

    2012-01-01

    Full Text Available La docencia de Toxicología en la Universidad de La Laguna (ULL se integra en diversas Licenciaturas y Grados tales como Farmacia, Ciencia y Tecnología de los Alimentos (CTA, Medicina, Náutica y Transporte Marítimo y el Máster Oficial de Seguridad y Calidad de los Alimentos. En la Licenciatura de Farmacia en la ULL, el Área de Toxicología imparte la asignatura troncal Toxicología de 7 créditos y dos asignaturas optativas, Drogodependencias y Toxicología Clínica y Laboral, de 4,5 créditos cada una. En el Grado en Farmacia, se imparte la asignatura obligatoria de Toxicología (9 ECTS y la asignatura optativa de Drogodependencias (6 ECTS. Asimismo, se imparte un total de 11 créditos en la Licenciatura de CTA quedando ésta extinguida en el curso académico 2013/2014. En la Licenciatura de Medicina, se imparte docencia de Toxicología en las asignaturas de Medicina Legal y Toxicología (asignado 1 crédito y Toxicología clínica (4,5 créditos mientras que en el Grado de Medicina se integra en las asignaturas Farmacología, anestesia y tratamiento del dolor (9 ECTS y Aspectos éticos, aspectos legales y aspectos humanísticos de la Medicina (6 ECTS. En ellas, la Toxicología tiene asignado 1 y 0,5 ECTS, respectivamente. La Licenciatura de Náutica y Transporte Marítimo, la docencia de Toxicología se engloba en una asignatura obligatoria mientras que en el Grado en Ingeniería Radioelectrónica se incluye en una asignatura optativa (3 ECTS. En la docencia de Postgrado, la Toxicología se imparte en el Máster Oficial en Seguridad y Calidad de los Alimentos desde dos módulos con 6 ECTS cada uno de ellos.

  2. 3D gravity inversion and thermodynamic modelling reveal properties of shallow silicic magma reservoir beneath Laguna del Maule, Chile

    Science.gov (United States)

    Miller, Craig A.; Williams-Jones, Glyn; Fournier, Dominique; Witter, Jeff

    2017-02-01

    Active, large volume, silicic magma systems are potentially the most hazardous form of volcanism on Earth. Knowledge of the location, size, and physical properties of silicic magma reservoirs, is therefore important for providing context in which to accurately interpret monitoring data and make informed hazard assessments. Accordingly, we present the first geophysical image of the Laguna del Maule volcanic field magmatic system, using a novel 3D inversion of gravity data constrained by thermodynamic modelling. The joint analysis of gravity and thermodynamic data allows for a rich interpretation of the magma system, and highlights the importance of considering the full thermodynamic effects on melt density, when interpreting gravity models of active magmatic systems. We image a 30 km3, low density, volatile rich magma reservoir, at around 2 km depth, containing at least 85% melt, hosted within a broader 115 km3 body interpreted as wholly or partially crystallised (>70% crystal) cumulate mush. Our model suggests a magmatic system with shallow, crystal poor magma, overlying deeper, crystal rich magma. Even though a large density contrast (-600 kg/m3) with the surrounding crust exists, the lithostatic load is 50% greater than the magma buoyancy force, suggesting buoyancy alone is insufficient to trigger an eruption. The reservoir is adjacent to the inferred extension of the Troncoso fault and overlies the location of an intruding sill, driving present day deformation. The reservoir is in close proximity to the 2.0 km3 Nieblas (rln) eruption at 2-3 ka, which we calculate tapped approximately 7% of the magma reservoir. However, we suggest that the present day magma system is not large enough to have fed all post-glacial eruptions, and that the location, or size of the system may have migrated or varied over time, with each eruption tapping only a small aliquot of the available magma. The presence of a shallow reservoir of volatile rich, near liquidus magma, in close

  3. Rapid uplift in Laguna del Maule volcanic field of the Andean Southern Volcanic zone (Chile) 2007-2012

    Science.gov (United States)

    Feigl, Kurt L.; Le Mével, Hélène; Tabrez Ali, S.; Córdova, Loreto; Andersen, Nathan L.; DeMets, Charles; Singer, Bradley S.

    2014-02-01

    The Laguna del Maule (LdM) volcanic field in Chile is an exceptional example of postglacial rhyolitic volcanism in the Southern Volcanic Zone of the Andes. By interferometric analysis of synthetic aperture radar (SAR) images acquired between 2007 and 2012, we measure exceptionally rapid deformation. The maximum vertical velocity exceeds 280 mm yr-1. Although the rate of deformation was negligible from 2003 January to 2004 February, it accelerated some time before 2007 January. Statistical testing rejects, with 95 per cent confidence, four hypotheses of artefacts caused by tropospheric gradients, ionospheric effects, orbital errors or topographic relief, respectively. The high rate of deformation is confirmed by daily estimates of position during several months in 2012, as measured by analysis of signals transmitted by the Global Positioning System (GPS) and received on the ground at three stations around the reservoir forming the LdM. The fastest-moving GPS station (MAU2) has a velocity vector of [-180 ± 4, 46 ± 2, 280 ± 4] mm yr-1 for the northward, eastward and upward components, respectively, with respect to the stable interior of the South America Plate. The observed deformation cannot be explained by changes in the gravitational load caused by variations in the water level in the reservoir. For the most recent observation time interval, spanning 44 d in early 2012, the model that best fits the InSAR observations involves an inflating sill at a depth of 5.2 ± 0.3 km, with length 9.0 ± 0.3 km, width 5.3 ± 0.4 km, dip 20 ± 3° from horizontal and strike 14 ± 5° clockwise from north, assuming a rectangular dislocation in a half-space with uniform elastic properties. During this time interval, the estimated rate of tensile opening is 1.1 ± 0.04 m yr-1, such that the rate of volume increase in the modelled sill is 51 ± 5 million m3 yr-1 or 1.6 ± 0.2 m3 s-1. From 2004 January to 2012 April the total increase in volume was at least 0.15 km3 over the 5.2-yr

  4. Características físico-químicas y determinación de plaguicidas en el agua de la laguna de Gandoca, Limón, Costa Rica

    Directory of Open Access Journals (Sweden)

    Marta Coll

    2004-12-01

    Full Text Available Parámetros físico-químicos fueron determinados en tres puntos de muestreo y a dos profundidades entre noviembre 1999 y abril 2000, en la laguna de Gandoca, Refugio Nacional de Vida Silvestre Gandoca-Manzanillo, Limón, Costa Rica. Se determinó la temperatura, turbidez, salinidad, nutrimentos y clorofilas en la laguna. Se detectó una haloclina presente a 3 m de profundidad y se describió una circulación de aguas con fuerte estratificación por haloclina pero con una interfase entre la laguna y el mar de aguas parcialmente mezcladas. No se detectaron procesos de eutrofización. La fluctuación observada en los nutrimentos y clorofilas correspondería a procesos de circulación normales y complejos en la laguna, claramente influenciada por las aguas continentales. Además, durante febrero 2000, se realizó un estudio preliminar para la detección de sustancias organocloradas y organofosforadas en los puntos de muestreo. El análisis de residuos realizado mediante extracción líquido-líquido no detectó la presencia en las aguas de la laguna de ninguna de las veinte sustancias consideradas. La no detección de éstas podría indicar que no están llegando a la laguna a través del agua de escorrentía, o bien que una vez presentes en la laguna han sido lavadas por las fuertes lluvias durante el muestreoNutrients and chlorophylls concentrations, as well as salinity, temperature and Secchi disk depth were determined from November 1999 to April 2000, at three stations and two depths, at Gandoca lagoon, Gandoca-Manzanillo National Wildlife Refuge, Limón, Costa Rica. Salinity profiles indicated that the lagoon was a salt wedge estuary with a partially mixed region near the mouth. No processes of eutrophication were found. The distribution and abundance of nutrients and chlorophylls showed a slight influence of continental water and water circulation patterns in the lagoon. A preliminary study was done in order to analyze the presence of 20

  5. Limnology in El Dorado: some surprising aspects of the regulation of phytoplankton productive capacity in a high-altitude Andean lake (Laguna de Guatavita, Colombia

    Directory of Open Access Journals (Sweden)

    Jhon Donato

    2012-09-01

    Full Text Available High-altitude mountain lakes remain understudied, mostly because of their relative inaccessibility. Laguna de Guatavita, a small, equatorial, high-altitude crater lake in the Eastern Range of the Colombian Andes, was once of high cultural importance to pre-Columban inhabitants, the original location of the legendary El Dorado. We investigated the factors regulating the primary production in Laguna de Guatavita (4°58’50” N - 73°46’43” W, alt. 2 935m.a.s.l., area: 0.11km², maximum depth: 30m, during a series of three intensive field campaigns, which were conducted over a year-long period in 2003-2004. In each, standard profiles of temperature, oxygen concentration and light intensity were determined on each of 16-18 consecutive days. Samples were collected and analysed for chlorophyll and for biologically-significant solutes in GF/F-filtered water (NH4+, NO3- , NO2-; soluble reactive phosphorus. Primary production was also determined, by oxygen generation, on each day of the campaign. Our results showed that the productive potential of the lake was typically modest (campaign averages of 45-90mg C/m².h but that many of the regulating factors were not those anticipated intuitively. The lake is demonstrably meromictic, reminiscent of karstic dolines in higher latitudes, its stratification being maintained by solute- concentration gradients. Light penetration is poor, attributable to the turbidity owing to fine calcite and other particulates in suspension. Net primary production in the mixolimnion of Laguna de Guavita is sensitive to day-to-day variations in solar irradiance at the surface. However, deficiencies in nutrient availability, especially nitrogen, also constrain the capacity of the lake to support a phytoplankton. We deduced that Laguna de Guatavita is something of a limnological enigma, atypical of the common anticipation of a “mountain lake”. While doubtlessly not unique, comparable descriptions of similar sites elsewhere

  6. Laguna de Mucubají. Propuesta didáctica para la enseñanza de procesos geomorfológicos desde las Ciencias de la Tierra

    Directory of Open Access Journals (Sweden)

    Ramón Labarca-Rincón

    2016-12-01

    Full Text Available Esta investigación tiene como objetivo proponer el paisaje de la Laguna de Mucubají como recurso didáctico para la enseñanza de procesos y formas glaciales en la asignatura Ciencias de la Tierra. Se empleó una metodología descriptiva y proyectiva, bajo un diseño de campo y no experimental. Las técnicas utilizadas son observación, encuesta y revisión documental. En el diagnóstico de los “recursos didácticos”, más del 80% coincide en que el docente no utiliza recursos relacionados con la realidad, debido a la ausencia de recursos didácticos basados en paisajes naturales. En los resultados de “nivel de conocimiento”, más del 60% de los encuestados desacertó en los ítems referidos a formas de erosión y formas de acumulación glacial, lo que denota debilidad en el dominio del conocimiento. Se elaboró un paquete didáctico basado en el paisaje de la Laguna de Mucubají con la finalidad de estimular en los estudiantes el aprendizaje de procesos geomorfológicos. Palabras clave Laguna de Mucubají, recursos didácticos, paisaje natural, procesos y formas glaciales Mucubají’s Lagoon. Didactic Offer for Teaching Geomorphologic Processes from the Sciences of the Earth Abstract This investigation has as its aim propose the landscape of Mucubají's Lagoon as a didactic resource for the education of glacial processes and forms in the subject Sciences of the Earth. A descriptive and projective methodology was used, under a field design and not experimental. The techniques used are observation, survey and documentary review. In the diagnosis of the “didactic resources", more than 80% agreed that the teacher did not use resources related to reality, due to the absence of didactic resources based on natural landscapes. In the results of “level of knowledge", more than 60 % of respondents were wrong in the items referred to the erosion forms and accumulation of glacial forms, which denotes weaknesses in the domain of knowledge

  7. Evaluación de la riqueza de especies de peces en las lagunas costeras mexicanas: estudio de un caso en el Golfo de México

    Directory of Open Access Journals (Sweden)

    Marco Aurelio Pérez-Hernández

    2000-06-01

    Full Text Available Se analiza la manera como se ha conformado el conocimiento de la ictiofauna del sistema estuarino-lagunar de Tuxpan-Tampamachoco, en el estado mexicano de Veracruz. Se elaboró un inventario de los peces conocidos hasta la fecha en dicho sistema (N= 179, a partir de listas previamente publicadas y de muestreos propios en las áreas someras de la laguna cubiertas por pastos marinos, que nos permitieron detectar 14 especies antes desconocidas en el área. Al comparar los distintos listados se observa una escasa similitud, la cual se atribuye a las diferencias en las estrategias de recolecta empleadas. Al menos con los datos actualmente disponibles, la riqueza íctica registrada en las lagunas costeras del Golfo de México no está relacionada con su área, como se ha sugerido, sino con el número de inventarios disponibles para cada laguna, pues éste involucra importantes diferencias en el esfuerzo de muestreo y en las estrategias de recolecta. Se recomienda un diseño de muestreo que contemple: a emplear la mayor variedad posible de artes de pesca, b recolectar en todos los tipos de microhábitat y, c preferir los muestreos cada dos o tres meses por dos o más años sobre los muestreos mensuales durante un sólo año.We analyze the origin of knowledge about fish species richness in the Tuxpan-Tampamachoco estuarine system, in Veracuz, México. A complete inventory of the fish species known to date for this system (N=179 was elaborated from published lists and from sampling seagrass meadows of Tampamachoco Lagoon, which yielded 14 previously unknown species. When compared, the different lists showed a low similarity that may reflect differences in sampling methods and collecting strategies. Current data suggest that fish species richness in Mexican coastal lagoons (Gulf of Mexico is not related with lagoon surface area, as has been suggested, but with number of inventorie. A sampling design for the assessment of fish species richness in estuarine

  8. Potencial Productivo de una Laguna artificial en el desarrollo del cultivo de tilapia (Potencial Productive of artificial lagoon on development of tilapia

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    Ruiz Velazco Arce Javier Marcial de Jesús

    2007-03-01

    Full Text Available El estudio se realizó en la laguna de Mora,ubicada, a 4 km de la ciudad Tepic, capitaldel estado de Nayarit, en México. El objetivofue generar conocimiento acerca delpotencial acuícola de esta laguna, a partirdel análisis de las variables que explican elcomportamiento de su metabolismoproductivo en un ciclo anual. Con ello,identificar las estrategias de explotación másadecuadas para el desarrollo de laproducción acuícola de tilapia, en coherenciacon sus características de productividadnatural y las posibilidades de intensificaciónde la actividad, sin perjuicio de sumetabolismo productivo. Se partió de unaprimera fase de análisis cartográfico, seguidadel estudio de factibilidad ambiental,productividad natural y las condicioneshidrológicas mínimas para la subsistencia deorganismos cultivables. Después de esto, setuvieron elementos suficientes paradescartar alguna dificultad ambiental ohidrológica limitante para elaprovechamiento acuícola. Los resultados deltrabajo mostraron características deproductividad que ubican a este sistema enun nivel mesotrófico con variableshidrológicas consideradas de aptitud para unciclo del cultivo de tilapias en las estacionesde primavera, verano y parte de otoño.Estos resultados servirán de base para eldiseño, proyección y ejecuci��n de proyectosde inversión acuícola particulares para elsistema, cuyo plan de manejo se percibenecesario a fin de garantizar lasustentabilidad ambiental de suaprovechamiento. La tilapia es una especieque cuenta con buena aceptación en elmercado, sobre todo en el ámbito mundial,donde su cultivo genera empleo y divisas.Este estudio pretende contribuir al desarrollotecnológico del cultivo de tilapia para lasespecies Oreochomis aureus y Oreocchomisniloticus, en condiciones de cultivo extensivoen la laguna de Mora en Nayarit, México.

  9. Evolución trófica de Laguna Grande de San Pedro (VIII Región, Chile durante el último siglo, mediante el análisis de registros sedimentarios Trophic evolution of Laguna Grande de San Pedro (VIII Region, Chile during the last century, by means of the analysis of sedimentary records

    Directory of Open Access Journals (Sweden)

    FABIOLA CRUCES

    2001-06-01

    Full Text Available La presente investigación realizó una reconstrucción de la evolución trófica de Laguna Grande de San Pedro (VIII Región, Chile durante el último siglo, a través del análisis estratigráfico de diatomeas y registros geoquímicos preservados en un núcleo de sedimento obtenido en el lago. Los resultados obtenidos señalan que la comunidad de diatomeas ha variado su composición a través del tiempo, reconociéndose cuatro períodos distintos, que representan cada uno de ellos una condición trófica diferente. Por otra parte, los registros geoquímicos aumentan sus tasas de acumulación hacia los estratos superficiales del perfil, evidenciando un aumento de la productividad hacia la actualidad. De acuerdo a lo anterior, es posible concluir que la productividad de Laguna Grande ha experimentado importantes cambios, evolucionando desde un sistema oligo-mesotrófico (período más antiguo a uno eutrófico (período reciente. Los cambios más drásticos habrían sucedido en las últimas décadas, como respuesta al fuerte desarrollo de actividades forestales y de urbanización en la cuenca de este sistemaThis research reconstructs the trophic evolution of Laguna Grande de San Pedro (VIII Region, Chile during the last century, through both the stratigraphic analyses of diatom remains and geochemical parameters preserved in a sediment core obtained in this lake. The results obtained show that the community of diatoms has changed its composition throughout time, showing four different periods, representing each one a distinctive trophic condition. On the other hand, the geochemical records increase their accumulation rates to the profile surface layers, making evident an increase of the productivity to the present time. In this context, it is possible to conclude that the productivity at Laguna Grande has experienced significant changes, evolving from an oligo-mesotrophic system (earlier period to an eutrophic one (recent period. The most drastic

  10. Estudios de interés tafonómico en los restos óseos humanos de Laguna Tres Reyes 1 (Partido de Adolfo Gonzales Chaves, provincia de Buenos Aires) Taphonomic studies of human bones from Laguna Tres Reyes 1 (Gonzales Chaves District, Buenos Aires province, Argentina)

    OpenAIRE

    Mariela Edith González

    2007-01-01

    En este trabajo se presentan los resultados del análisis de los efectos tafonómicos del registro bioarqueológico del sitio Laguna Tres Reyes 1 (Partido de Adolfo Gonzales Chaves), realizado en el marco de la tesis de licenciatura. La metodología consistió en el examen macroscópico de la superficie cortical de cada elemento esqueletal sobre el conjunto de entierros primarios. Las variables analizadas fueron: marcas de raíces, depositación química (carbonato de calcio y manchas de manganeso), p...

  11. Validation of a new version of software for monitoring the core of nuclear power plant of Laguna Verde Unit 2, at the end of Cycle 10; Validacion de una nueva version del software para monitoreo del nucleo de la Central Laguna Verde Unidad 2, al final del Ciclo 10

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, G.; Calleros, G.; Mata, F. [Comision Federal de Electricidad, Central Nucleoelectrica de Laguna Verde, Carretera Cardel-Nautla Km 42.5, Veracruz (Mexico)], e-mail: gabriel.hernandez05@cfe.gob.mx

    2009-10-15

    This work shows the differences observed in thermal limits established in the technical specifications of operation, among the new software, installed at the end of Cycle 10 of Unit 2 of nuclear power plant of Laguna Verde, and the old software that was installed from the beginning of the cycle. The methodology allowed to validate the new software during the coast down stage, before finishing the cycle, for what could be used as tool during the shutdown of Unit 2 at the end of Cycle 10. (Author)

  12. El caso del Outburst Flood histórico de la laguna Derrumbe, Cholila, Chubut: Colapso de dique Morénico en la Cordillera Norpatagónica The historic outburst flood of the laguna Derrumbe, Cholila, Chubut: Fast glacier retreat and moraine dam failure in North Patagonian Cordillera

    Directory of Open Access Journals (Sweden)

    Bruno Colavitto

    2012-09-01

    Full Text Available La laguna Derrumbe es un cuerpo de agua ubicado en los Andes Norpatagónicos en la provincia de Chubut, Argentina. Está contenida en un circo glaciario y endicada por una morena frontal del glaciar homónimo. A través del reconocimiento de campo se pudo describir a esta laguna y a un importante depósito rocoso que se halla aguas abajo de la misma, interpretado como un depósito de outburst flood. Estos depósitos son generados por procesos de alta energía relacionados con la rotura de un dique natural, en este caso un dique morénico. El estudio realizado permitió concluir que la morena frontal del glaciar Derrumbe sufrió una rotura parcial en tiempos históricos, desatando así una inundación súbita aguas abajo de la laguna, a través del valle del río Tigre, en la localidad de Cholila. En este trabajo se analizaron las posibles causas que dieron lugar a la rotura, la cual probablemente sea producto del rápido retroceso que el glaciar experimentó durante la década del ´50 y principios del ´60. Retroceso comparable con el ocurrido en muchos de los cuerpos glaciares de los Andes Patagónicos durante el último siglo.The Laguna Derrumbe is a body of water located in the North Patagonian Andes, in Chubut province, Argentina. This lake is contained in a glacial cirque and dammed by the terminal moraine of the namesake glacier. Through field survey it was possible to describe this lake and an important rocky deposit downstream of it, which is interpreted as an outburst flood deposit. These deposits are generated by high-energy processes related to the failure of a natural dam, in this case a moraine dam. The study made allowed to conclude that the frontal moraine of the Derrumbe glacier suffered a partial rupture in historic times, unleashing a flash flood downstream to the lake, through the Tigre river valley in the town of Cholila. In this work the possible causes that led to the failure are discussed, concluding that the main cause

  13. Fuel management inside the reactor. Report of generation of the nuclear bank for the fuel of the initial load of the Laguna Verde U-1 reactor with the FMS codes; Administracion de combustible dentro del reactor. Reporte de generacion del banco nuclear para el combustible de la carga inicial del reactor de Laguna Verde U-1 con los codigos del FMS

    Energy Technology Data Exchange (ETDEWEB)

    Alonso V, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Torres A, C. [CFE, Veracruz (Mexico)

    1991-06-15

    In this work in a general way the form in that it was generated the database of the initial fuel load of the Laguna Verde Unit 1 reactor is described. The initial load is formed with fuel of the GE6 type. The obtained results during the formation of the database in as much as to the behavior of the different cell parameters regarding the one burnt of the fuel and the variation of vacuums in the coolant channel its are compared very favorably with those reported by the General Electric fuel supplier and reported in the design documents of the same one. (Author)

  14. Validation of a new software version for monitoring of the core of the Unit 2 of the Laguna Verde power plant with ARTS; Validacion de una nueva version del software para monitoreo del nucleo de la Unidad 2 de la Central Laguna Verde con ARTS

    Energy Technology Data Exchange (ETDEWEB)

    Calleros, G.; Riestra, M.; Ibanez, C.; Lopez, X.; Vargas, A.; Mendez, A.; Gomez, R. [CFE, Central Nucleoelectrica de Laguna Verde, Alto Lucero, Veracruz (Mexico)]. e-mail: gcm9acpp@cfe.gob.mx

    2005-07-01

    In this work it is intended a methodology to validate a new version of the software used for monitoring the reactor core, which requires of the evaluation of the thermal limits settled down in the Operation Technical Specifications, for the Unit 2 of Laguna Verde with ARTS (improvements to the APRMs, Rod Block Monitor and Technical specifications). According to the proposed methodology, those are shown differences found in the thermal limits determined with the new versions and previous of the core monitoring software. Author)

  15. Programa educativo de salud bucodental dirigido a las personas adultas mayores del grupo amor y alegría, de Laguna de Alfaro Ruiz/ Oral health education program aimed to “Amor y Alegría” group, on Laguna of Alfaro Ruiz

    OpenAIRE

    Villalobos Rodríguez, Melania

    2011-01-01

    El objetivo principal de este trabajo fue medir los beneficios en la salud oral de un grupo de 21 mujeres adultas mayores vecinas de Laguna de Zarcero, en respuesta a su participación en la conformación de un programa orientado a promover la salud oral y a prevenir las enfermedades dentales más frecuentes. Las señoras son miembros del grupo ?Amor y Alegría? perteneciente a la Asociación Gerontológica Costarricense (AGECO). Con fines motivadores, se usaron principios andragógicos los cuales in...

  16. Ictiofauna de la Laguna Yahuarcaca y aspectos tróficos y reproductivos de cinco especies predominantes, Leticia - Colombia Ictiofauna de la Laguna Yahuarcaca y aspectos tróficos y reproductivos de cinco especies predominantes, Leticia - Colombia.

    Directory of Open Access Journals (Sweden)

    Mojica José Iván

    2000-06-01

    Full Text Available Las planicies de inundación del río Amazonas son sistemas pulsantes altamente productivos desde un punto de vista ecológico, debido principalmente al aporte periódico de sedimentos que son arrastrados desde la cordillera por las aguas del río. En Colombia, estos sistemas Amazónicos no han sido estudiados intensamente, razón por la cual se realizó este estudio en una laguna de desborde del plano de inundación del río Amazonas en cercanías de la ciudad de Leticia. Se realizaron muestreos ictiológicos en cuatro épocas de una año, correspondientes a diferentes niveles de las aguas del río Amazonas, aguas ascendentes (abril, altas (junio descendentes (julio y bajas (noviembre, con el fin de estudiar la variación de la comunidad de peces en el tiempo y crear una colección de referencia de la laguna Yahuarcaca. Se encontraron 134 especies de las cuales 54 son nuevos registros para la amazonía colombiana. La comunidad de peces presenta cambios significativos en su composición y abundancia a lo largo

  17. Evaluando los conocimientos previos de los alumnos a través de pruebas objetivas: ¿opción múltiple o test de lagunas?

    Directory of Open Access Journals (Sweden)

    Lucha Cuadros, Rosa M.

    2011-03-01

    Full Text Available En los test utilizados para comprobar los conocimientos previos de los alumnos y conocer sus necesidades, se suele utilizar pruebas indirectas tipo opción múltiple. ¿Son este tipo de pruebas las más adecuadas para evaluar los conocimientos de los estudiantes? Para dilucidar esta cuestión, hemos analizado los resultados de dos tipos de pruebas indirectas evaluadas objetivamente: el test de opción múltiple y el test de lagunas. En la discusión de los resultados se analizan las implicaciones pedagógicas que la elección del tipo de prueba ofrece tanto para el profesor como para el alumno.

  18. [Feeding habits and trophic ecology of the fish Lutjanus griseus (Pisces: Lutjanidae) associated with submerged vegetation in Laguna de Términos, Campeche, Mexico].

    Science.gov (United States)

    Guevara, Emma; Alvarez, Hernán; Mascaró, Maite; Rosas, Carlos; Sánchez, Alberto

    2007-01-01

    In Campeche, Mexico, the Laguna de Términos has Thalassia testudinum beds inhabited by the grey snapper, Lutjanus griseus (Linnaeus 1758). Along one year, we collected 994 individuals and 672 had food in their stomachs; we recorded number, weight, and frequency oftrophic groups, and the index of relative importance. Dominant food components were Farfantepenaeus duorarum and Palemonetes octaviae, Eucinostomus gula (Cuvier 1830) and Libinia dubia. Salinity and temperature were related to the number of individuals collected and with greater fish consumption by large L. griseus. The trophic niche breadth index was calculated for six size-classes of fish. The smallest and the largest fish had the lowest index values, whereas medium-size snappers had higher values. This snapper has a preference for habitats with submerged vegetation. The percentage of fish with food in their stomachs was higher during dark hours, providing evidence of the nocturnal habits of this fish.

  19. Modernidad arquitectónica atlántica y restauración en Canarias: la casa Ossuna de Alejandro Beautell en La Laguna

    Directory of Open Access Journals (Sweden)

    Carlos Javier Castro Brunetto

    2013-12-01

    Full Text Available This article discusses the renovation of the Ossuna House (2009-2011 in San Cristóbal de la Laguna in Tenerife. Faced with a plethora of options Alejandro Beautell harmonises the principles of popular Atlantic architecture together with new building materials from contemporary architecture in the Canary Islands. By doing so, he takes on the challenge of renovating a domestic space from the eighteenth century. The materials provide the project with a great conceptual uniqueness as they combine the historic value of the building with a touch of modernity. The timelessness of certain architectural resources complicates the narrative as well as the ability to estimate authenticity; however, the technical rigour of the processes and actions that are completely reversible are the most relevant part of the project.

  20. Population fluctuations of Pyrodinium bahamense and Ceratium furca (Dinophyceae) in Laguna Grande, Puerto Rico, and environmental variables associated during a three-year period.

    Science.gov (United States)

    Sastre, Miguel P; Sánchez, Efrain; Flores, Marineé; Astacio, Samuel; Rodríguez, Julianna; Santiago, Melissa; Olivieri, Karina; Francis, Veronica; Núñez, Juan

    2013-12-01

    Bioluminescent bays and lagoons are unique natural environments and popular tourist attractions. However, the bioluminescence in many of these water bodies has declined, principally due to anthropogenic activities. In the Caribbean, the bioluminescence in these bays and lagoons is mostly produced by the dinoflagellate Pyrodinium bahamense var. bahamense. Laguna Grande is one of the three year-round bioluminescent water bodies in Puerto Rico that are known to remain but P. bahamense var. bahamense density fluctuations have not been studied. In this study we describe water quality parameters and density fluctuations of the most common dinoflagellates in Laguna Grande, P. bahamense var. bahamense and Ceratium furca, over a three-year period. For this, three sampling stations were established in Laguna Grande from which water samples were collected in triplicate and analyzed for temperature, phosphates, nitrates, salinity, water transparency, fluorescence, and dinoflagellate densities, at the water surface and at 2m depth, from May 2003 to May 2006. The results showed a density fluctuation pattern for P. bahamense var. bahamense, where higher densities were observed mainly from April to September, and lower densities from October to February. Density fluctuations of C. furca were more erratic and a repetitive pattern was not observed. Densities of P. bahamense var. bahamense ranged from 0.48 to 90978 cells/L and densities of C. furca ranged from 0 to 11,200 cells/L. The mean population density throughout the sampling period was significantly higher in P. bahamense var. bahamense (mean = 18,958.5 cells/L) than in C. furca (mean = 2601.9 cells/L). Population densities of P. bahamense var. bahamense were negatively correlated with C. furca densities during the first year of sampling; however, they were positively correlated during the third year. Non-significant differences between surface and 2m depth samples were observed for temperature, phosphates, nitrates, salinity

  1. Population fluctuations of Pyrodinium bahamense and Ceratium furca (Dinophyceae in Laguna Grande, Puerto Rico, and environmental variables associated during a three-year period

    Directory of Open Access Journals (Sweden)

    Miguel P. Sastre

    2013-12-01

    Full Text Available Bioluminescent bays and lagoons are unique natural environments and popular tourist attractions. However, the bioluminescence in many of these water bodies has declined, principally due to anthropogenic activities. In the Caribbean, the bioluminescence in these bays and lagoons is mostly produced by the dinoflagellate Pyrodinium bahamense var. bahamense. Laguna Grande is one of the three year-round bioluminescent water bodies in Puerto Rico that are known to remain but P. bahamense var. bahamense density fluctuations have not been studied. In this study we describe water quality parameters and density fluctuations of the most common dinoflagellates in Laguna Grande, P. bahamense var. bahamense and Ceratium furca, over a three-year period. For this, three sampling stations were established in Laguna Grande from which water samples were collected in triplicate and analyzed for temperature, phosphates, nitrates, salinity, water transparency, fluorescence, and dinoflagellate densities, at the water surface and at 2m depth, from May 2003 to May 2006. The results showed a density fluctuation pattern for P. bahamense var. bahamense, where higher densities were observed mainly from April to September, and lower densities from October to February. Density fluctuations of C. furca were more erratic and a repetitive pattern was not observed. Densities of P. bahamense var. bahamense ranged from 0.48 to 90 978 cells/L and densities of C. furca ranged from 0 to 11 200 cells/L. The mean population density throughout the sampling period was significantly higher in P. bahamense var. bahamense (mean=18 958.5 cells/L than in C. furca (mean=2 601.9 cells/L. Population densities of P. bahamense var. bahamense were negatively correlated with C. furca densities during the first year of sampling; however, they were positively correlated during the third year. Non-significant differences between surface and 2m depth samples were observed for temperature

  2. EVALUACIÓN DEL DISEÑO Y CONSTRUCCIÓN DE LOS SENDEROS Y MALECONES DE LA LAGUNA DE ZAPOTLÁN

    OpenAIRE

    2012-01-01

    El presente trabajo se realizó de febrero a octubre de 2011 utilizando para ello un estudio ecológico, transversal y descriptivo en el que se describieron las características arquitectónicas en su primera etapa de los senderos y malecones de la laguna de Zapotlán. Se realizó el estudio de impacto ambiental con su mecánica de suelo, levantamiento topográfi co, análisis de medio físico trasformado, análisis de las vías de comunicación, análisis de infraestructuras especiales, análisis económic...

  3. Cianofitas de los sistemas fluvio-lagunares Pom-Atasta y Palizada del Este, adyacentes a la Laguna de Términos, Campeche, México

    Directory of Open Access Journals (Sweden)

    R.E. Muciño-Márquez

    2015-07-01

    Full Text Available Las cianofitas son un grupo muy diverso de microorganismos procariontes fotosintetizadores, con una amplia distribución en diferentes ambientes tanto terrestres como acuáticos. Algunas especies pueden formar florecimientos algales nocivos o tóxicos. El objetivo de este estudio consistió en identificar la composición de las especies de cianofitas en los sistemas fluvio-lagunares Pom-Atasta (PA y Palizada del Este (PE. Se recolectaron muestras de agua tanto en superficie como medio fondo para cada laguna, en febrero del 2011, en 10 sitios utilizando una botella van Dorn. Se identificaron 21 taxones, de las cuales siete especies forman florecimientos algales como: Pseudanabaena catenata, P. limnetica, Anabaenopsis circularis, A. elenkinii, Aphanizomenon cf. ovalisporum, Ap. schindleri y Dolichospermum circinalis. Además, se reportan dos nuevos registros correspondientes a Aphanizomenon cf. ovalisporum y Ap. schindleri.

  4. Acción bactericida de la laguna minero-medicinal "Santa Cruz de las Salinas" Chilca, Lima-Perú

    Directory of Open Access Journals (Sweden)

    Gloria Chacón Roldán

    2014-06-01

    Full Text Available El presente estudio trata de la acción bactericida in vitro e in vivo del agua de la laguna minero-medicinal "Santa Cruz de las Salinas", Chilca. Investigaciones realizadas en el período Febrero 1977 -Julio 1979 en el Instituto de Salud, Lima, han probado que esta agua ejerce acción bacteriostática y bactericida sobre un germen altamente patógeno para el organismo humano de tipo Gram negativo (Cepa So/mone/Ia typhy TY2. Pruebas de toxicidad de esta agua en el organismo animal se han hecho inoculando 2 grupos de ratones por vías endovenosa e intraperitoneal, demostrando que no ejerce acción tóxica, más bien produce una acción estimulante sobre las células sanguíneas. Se han elaborado 17 Cuadros y 37 figuras.

  5. Efectos antrópicos sobre las praderas sumergidas de carófitos en una laguna cárstica

    Directory of Open Access Journals (Sweden)

    Sosnovsky, Alejandro

    2005-06-01

    Full Text Available Charophytes are submerged macrophyte algae often found in diverse aquatic habitats. Chara-dominated lakes are typically hard water, calcium-rich and low in phosphate. La Colgada is a 18 m deep, 103 ha small lake located in a tourist area, which has partly resulted in nutrient increases in recent years. Chara hispida var. major (Hartm. R.D. Wood and Chara hispida f. polyacantha (A. Braun R.D. Wood meadows are extensive in this ecosystem, but their distribution are influenced by human activities. Negligible densities of C. hispida, always covered by epiphytes, were recorded in the shores adjacent to tourist areas. Horizontal cover and biomass distributions were heterogeneous throughout the lake (0,95 ± 0,55 kg DW•m-2, with minimum values nearby the tourist area (0,68 ± 0,32 kg DW•m-2. Charophyte biomass was inversely related to depth in areas not influenced by anthropogenic impacts. However, that relationship did not occur in anthropized areas. The biomass range of Charophytes in La Colgada lake, 0,22-2,27 kg DW•m-2, was much higher than that recorded in other world lakes and wetlands.Los carófitos son algas macrófitas que viven sumergidas en aguas con características físico-químicas muy diferentes. La Colgada es una laguna de 103 ha y 18 m de profundidad máxima ubicada en una zona de gran afluencia turística (Parque Natural Las Lagunas de Ruidera, Albacete-Ciudad Real, en la que los nutrientes han ido aumentando durante las últimas décadas. Los fondos de esta laguna están cubiertos parcialmente por formaciones monoespecíficas de Chara hispida var. major (Hartm. R.D. Wood y Chara hispida f. polyacantha (A. Braun R.D. Wood, cuya distribución está siendo afectada por las actividades humanas. Las densidades más bajas de C. hispida, siempre cubierta por abundantes algas epífitas filamentosas, se registraron en los bordes próximos a la zona más urbanizada. La distribución horizontal y la biomasa seca de C

  6. Variación anual de la biomasa de Nymphoides fallax Ornduff (Menyanthaceae en la Laguna de Tecocomulco, Hidalgo, México

    Directory of Open Access Journals (Sweden)

    Agustin Quiroz-Flores

    2015-07-01

    Full Text Available Durante un ciclo anual se cuantificó la variación en la estratifi cación vertical de la biomasa deNymphoides fallaxy se analizaron las variables físicas y químicas del agua y sedimentos de la laguna de Tecocomulco, Hidalgo. La producción anual neta de N. fallax fue de 3 070.1 g PS m2. En el mes de junio la biomasa alcanzó su máximo (958.4 g PS m2 . La contribución de biomasa foliar de N. fallax a la proporción total de biomasa representa el 10%, la de peciolos alcanza el 40% y la contribución de biomasa subterránea equivale en ocasiones a más del 50%. El nivel de fósforo en los sedimentos se encuentra por arriba de la cantidad necesaria para sostener la producción vegetal (= 0.04%. Por los resultados obtenidos en este estudio, se puede señalar que en aquellas zonas ribereñas de la laguna en donde los agricultores han construido bordos, se propicia que durante la época de lluvias la columna de agua cambie bruscamente sus dimensiones pasando de 10 cm hasta alcanzar los 75 cm de profundidad y se eleven los niveles de fósforo en agua y sedimentos, lo que a su vez induce queNymphoides fallaxse vea estresada, y en un caso extremo, temporalmente sea sustituida por aquellas especies mejor adaptadas a las nuevas condiciones físicas y químicas del medio.

  7. Formación Laguna Tordillo: Volcanismo dacítico eoceno en el Macizo del Deseado, provincia de Santa Cruz

    Directory of Open Access Journals (Sweden)

    D. Guido

    2004-12-01

    Full Text Available Se determinó una nueva entidad formacional para la provincia geológica Macizo del Deseado. Se trata de rocas volcánicas melanocráticas que se presentan como dos afloramientos en inmediaciones de la laguna Tordillo, en el sector oriental del macizo del Deseado. Son lavas de color negro a rojizo, de textura porfírica con fenocristales de labradoritas (An55-57 inmersos en una pasta de textura hialocristalina, de tipo hialofítica. Además, poseen xenolitos de roca volcánica de textura glomeroporfírica con fenocristales de labradoritas (An56-59 y enstatitas (En56-Fs40-Wo4, con rebordes de reacción pigeoníticos (En44-Fs47-Wo9. Los análisis de elementos mayoritarios y traza las definen como lavas dacíticas, de tipo subalcalino y con afinidad calcoalcalina. Las relaciones estratigráficas evidencian una edad post-Jurásico superior, la cual fue confirmada mediante un fechado radimétrico K/Ar en roca total (fracción vidrio, que resultó en 40,8 ± 2,4 Ma (Eoceno. Teniendo en cuenta el marco paleogeográfico y geotectónico paleógeno para la Patagonia, se propone que estas rocas se generaron como consecuencia de un subplacado básico de magmas, posiblemente vinculados con el Basalto Cerro del Doce o unidades paleógenas correlacionables. Sin embargo, no se descarta una vinculación entre las rocas de la Formación Laguna Tordillo y las piroclastitas de la Formación o Grupo Sarmiento.

  8. Lake records of Northern Hemisphere South American summer monsoon variability from the Cordillera Oriental, Colombia: Initial results from Lago de Tota and Laguna de Ubaque

    Science.gov (United States)

    Escobar, J.; Rudloff, O.; Bird, B. W.

    2013-12-01

    The lack of terrestrial paleoclimate records from the Northern Hemisphere Andes with decadal resolution has meant that our understanding of abrupt South American summer monsoon (SASM) variability during the Holocene is almost exclusively based on data from Southern Hemisphere sites. In order to develop a more integrated and complete picture of the SASM as a system and its response during rapid climate changes, high-resolution paleoclimate records are needed from the Northern Hemisphere Andes. We present initial results from analysis of lake sediment cores that were collected from Lago de Tota (N 5.554, W 72.916) and Laguna de Ubaque (N 4.500, W 73.935) in the Eastern Cordillera of the Colombian Andes. These sediment cores were collected in July 2013 as part on an ongoing paleoclimate research initiative in Colombia. Located in the Boyacá Provence, Lago de Tota is the largest high-altitude lake (3010 masl) in the Northern Hemisphere Andes and the second largest Andean lake in South America. As such, hydrologic changes recorded in the lake's sediment record reflect regional climate responses. Lago de Ubaque (2070 masl) is a small east facing moraine-dammed lake near the capital of Bogotá that contains finely laminated clastic sediments. The initial sedimentological and chronological results demonstrate that Lago de Tota and Laguna de Ubaque have excellent potential for resolving Northern Hemisphere SASM variability at decadal time scales or better. Such records will provide important counterparts to high-resolution paleoclimate records from the Southern Hemisphere Andes.

  9. 30 years in the Veracruz state coast landscape: Laguna Verde nuclear power station. 1. ed.; 30 anos de paisaje costero veracruzano: Central Nucleoelectrica Laguan Verde

    Energy Technology Data Exchange (ETDEWEB)

    Guevara, S; Moreno Casasola, P; Castillo Campos, G; Dorantes, C; Gonzalez Garcia, F; Halffter, G; Isunza, E; Lot H, A; Mendoza, R; Paradowska, K; Priego, A; Sanchez Vigil, C; Vazquez, G [Comision Federal de Electricidad and Instituto Nacional de Ecologia A.C. (Mexico)

    2008-07-01

    36 years ago one of the most important power projects of Mexico was born; the design and construction of the Nuclear power station Laguna Verde. This project became reality thanks to the commitment of a group of Mexican professionals that gave the best of them for its accomplishment. At that time, there was not in Mexico a legislation that contemplated the environmental protection; nevertheless, the Mexican Constitution anticipates that when in the country there is not legislation for the development of a project, this must adopt the legislation of the country that is selling it. In the specific case of Laguna Verde, the legislation of the United States of America was adopted and in the environmental part it had to issue the first Manifest of Environmental impact, that was called Informe Ambiental para la Contruccion de Laguna Verde en el Estado de Veracruz. This study was performed by several national as well as foreign institutions. Among the most outstanding are the Universidad Nacional Autonoma de Mexico, the Intituto Politecnico Nacional, the Universidad Veracruzana, the Intituto National para la Investigacion de Recursos Biologicos, the Instituto de Ecologia, A.C. With this report, the engineers undertook the task of designing and constructing, the biologists and ecologists to realize the studies to mitigate the effects caused to the environment during the construction and later, during the operation of the Nuclear power station. After 18 years of commercial operation of the power station the present book is completed, in which the results obtained in 1972, when the studies of the environmental report began are compared against the ones obtained throughout this period. It is important to see in the results of the different studies and indicators presented/displayed in this book, that the important changes on the environment are due, to the change of the ground use and the over-exploitation of the natural resources as it happens in almost all the country. The

  10. Evaluation of the integrity and duration of the Laguna Verde nuclear power plant life- Plant Life Management program (PLIM). TC MEX 04/53 Technical Cooperation Project; Evaluacion de la integridad y extension de vida de la planta de potencia nuclear Laguna Verde- Programa de manejo de vida de planta (PLIM). Proyecto de cooperacion tecnica TC MEX 04/53

    Energy Technology Data Exchange (ETDEWEB)

    Arganis J, C.R.; Diaz S, A.; Aguilar T, J.A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2006-07-01

    As part of the IAEA TC MEX 04/53 Project 'Evaluation of the integrity and extension of life of the Laguna Verde nuclear power plant Handling Program of plant' whose objective is the one of beginning the actions to apply the methodology of Handling of plant life in the Unit 1 of the Laguna Verde Nucleo electric Central for to obtain the Renovation of License in 2020 the ININ, through the Department of Synthesis and Characterization of materials has carried out more of 20 analysis of susceptibility to the intergranular cracking for corrosion under effort in interns so much of the reactor of the unit 1 like of the unit 2 documenting the current state of components based on the type or types of materials that conform them, to it thermomechanical history, operational and of production, as well as of the particularities associated to its use and operation. For the application of the methodology of life handling of plant 5 structure systems or pilot components were selected, to carry out the programs of handling of the aging and handling of plant life: The encircling of the reactor core (Core Shroud), the reactor pressure vessel (Reactor Pressure Vessel), the primary container (Primary Containment), the recirculation system of feeding water (Reactor Feed Water) and cables. (Author)

  11. REGISTROS NUEVOS O POCO CONOCIDOS DE AVES MIGRATORIAS EN LA LAGUNA DEL OTÚN, PARQUE NACIONAL NATURAL LOS NEVADOS, RISARALDA, COLOMBIA Records of New or Poorly Known Migratory Birds from Laguna del Otún, los Nevados National Natural Park, Risaralda, Colombia

    Directory of Open Access Journals (Sweden)

    ORLANDO ACEVEDO-CHARRY

    2013-04-01

    Full Text Available Colombia es un sitio importante para las aves migratorias. Sin embargo, aún falta mucho conocimiento de dónde estas se encuentran durante su paso o permanencia por el país y cuáles utilizan los páramos. Registramos nuevas especies de aves migratorias para la laguna del Otún, inmersa en un complejo de humedales declarados sitio Ramsar desde el 2008. La laguna está localizada en el Parque Nacional Natural Los Nevados a 3932 msnm, en ecosistema de páramo, en la Cordillera Central de los Andes de Colombia. Durante cinco salidas entre 2010 y 2012 se registraron cuatro nuevas especies de aves migratorias para el parque: Anas acuta, Pandion haliaetus, Riparia riparia y Dendroica petechia. Adicionalmente, se registró una ampliación del rango altitudinal para dos especies migratorias que solo habían sido registradas en la región a menos de 3500 msnm: Tringa flavipes e Hirundo rustica. Estas observaciones sugieren que dichas especies podrían tolerar condiciones de alta montaña y utilizar el páramo. Es necesario estudiar a fondo las dinámicas migratorias y el uso de hábitat de alta montaña por las aves migratorias.

  12. Evaluación de impacto ambiental por el método Batelle Columbus del túnel de desfogue de la laguna de Metztitlán, Estado de Hidalgo.

    OpenAIRE

    Mayra MENDOZA CARIÑO

    2010-01-01

    El Distrito de Riego 08 se localiza en la Cuenca de Metztitlán, en la Reserva de la Biósfera de la Barranca de Metztitlán (RBBM) parte Norte. El desbordamiento del río y la laguna Metztitlán ocasionan inundaciones en la zona con una frecuencia de 2.5 años (CNA, 2003). Aunque ya existen dos túneles de desfogue de la laguna al río Almolón, estos son insuficientes pues liberan el agua en más de seis meses por ello, la Comisión Nacional del Agua propone construir un nuevo túnel. El objetivo de es...

  13. Tratamiento de agua potable por filtración inducida en una laguna costera en el sur de Brasil Bank filtration drinking water treatment in a costal lagoon in south Brazil

    OpenAIRE

    Luis Guillermo Romero Esquivel; Bruno Segalla Pizzolatti; Mauricio Luiz Sens

    2012-01-01

    La filtración inducida (FI) consiste en obtener agua potable de pozos situados en acuíferos de aluvión u otro tipo de depósitos no consolidados conectados hidráulicamente con una fuente de agua superficial. La posibilidad de aplicar esta técnica en las riberas de la laguna Lagoa do Peri, Brasil, se evaluó a nivel piloto. Por medio de observación y de análisis granulométricos se determinó que el fondo de la laguna y el acuífero aledaño presentan una textura arenosa. Además, ensayos de permeáme...

  14. Turismo Sustentable como Alternativa de Desarrollo en las Comunidades de la Faja Petrolífera del Orinoco. Caso: Sector Laguna de Mamo, Municipio Independencia, Estado Anzoátegui, Venezuela

    Directory of Open Access Journals (Sweden)

    María Virginia Blanco

    2012-01-01

    Full Text Available La Laguna de Mamo tiene una superficie de 55 km2; recibe las aguas de los ríos Camoruco y Merey y desemboca en el Orinoco por el río Mamo. Está ubicada al sur-oeste del estado Anzoátegui en el municipio Independencia, parroquia Mamo y pertenece al Área Carabobo de la Faja Petrolífera del Orinoco. La zona en la que se ubica la Laguna de Mamo concentra grandes posibilidades de desarrollo turístico a nivel local, pues cuenta con varios sitios naturales para la recreación y el esparcimiento al aire libre; así como valores culturales que pueden ser aprovechados para el turismo de naturaleza, bajo la modalidad del turismo rural. Durante la celebración de las diversas fiestas patronales que se celebran en la zona, en temporadas de Semana Santa y Carnaval, las comunidades son visitadas por grupos de personas que se trasladan, principalmente en vehículos propios, a pasar el día en los ríos y lagunas. La zona se caracteriza por la presencia de gran variedad de cuerpos de agua, en torno a los cuales se desarrolla una de las principales actividades económicas de la región, como es la pesca. Estos cuerpos de agua, constituyen pequeños ecosistemas en los que habitan diversas especies de flora y fauna autóctonas y que también pueden ser aprovechadas con fines turísticos. El objetivo de la investigación consistió en identificar las posibilidades de desarrollo del turismo sustentable bajo la modalidad del turismo rural, en torno a la Laguna de Mamo, como una alternativa económica regional

  15. Aislamiento e identificación de diez cepas bacterianas desnitrificantes a partir de un suelo agrícola contaminado con abonos nitrogenados proveniente de una finca productora de cebolla en la Laguna de Tota, Boyacá, Colombia

    OpenAIRE

    ostos ortiz, olga lucia; Benavides López de Mesa, Joaquín; Quintero, Gladys

    2006-01-01

    Este articulo presenta los resultados de la versatilidad adaptativa y tolerancia de una consorcio bacteriano constituido por 10 cepas bacterianas endémicas de un suelo agrícola contaminado, proveniente de una finca productora de cebolla ubicada en la laguna de Tota en Aquitania, Boyacá, Colombia, expuesto al uso incontrolado de fertilizantes nitrogenados. La consorcio bacteriano aislado del suelo está conformado por: Bacillus megaterium, Bacillus licheniformis, Pseudomonas stutzeri, Acinetoba...

  16. Carotenogénesis de cinco cepas del alga Dunaliella sp. (Chlorophyceae aisladas de lagunas hipersalinas de Venezuela

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    Miguel Guevara

    2005-09-01

    Full Text Available Se realizaron cultivos discontinuos (medio Algal con 0.5 mM de NaNO3 y 27% de NaCl de cinco cepas de Dunaliella sp., aisladas de diferentes lagunas hipersalinas de Venezuela (Araya, Coche, Peonía, Cumaraguas y Boca Chica y una cepa de referencia (Dunaliella salina LB1644. Los bioensayos se mantuvieron a 25 ± 1 °C con aireación constante, fotoperiodo 12:12 y dos intensidades luminosas (195 y 390 µE.m-2.s-1 durante 30 días. El crecimiento celular se determinó diariamente mediante conteo celular en cámara de Neubaüer. La clorofila a y los carotenoides totales se analizaron al final del ensayo. Las mayores densidades celulares correspondieron a los ensayos de menor intensidad luminosa. La cepa que alcanzó la mayor densidad celular fue la aislada de Boca Chica (8 x10(6 y 2.5 x10(6 cel.ml-1 a 195 y 390 µE.m-2.s-1, respectivamente. El incremento de la intensidad luminosa en los cultivos produjo una disminución significativa de las tasas de crecimiento en todas las cepas. Los carotenoides totales por volumen fueron mayores a 390 µE.m-2 .s-1; siendo las cepas de referencia LB1644, Coche y Araya las que produjeron mayor cantidad (38.4; 32.8 y 21.0 µg.ml-1, respectivamente. El contenido de carotenoides totales por célula en los dos tratamientos fue significativamente diferente, obteniéndose la mayor concentración a 390 µE.m-2.s-1. Las cepas LB1644 y Coche fueron las que produjeron los valores más altos de carotenos (137.14 y 106.06 pg.cel-1, respectivamente. La cepa LB1644 presentó la mayor relación carotenoides totales:clorofila a (20:1 a 195 µE.m-2.s-1, mientras que en la cepa Coche no se evidenciaron diferencias significativas entre las dos intensidades (15:1. El resto de las cepas mostraron relaciones inferiores a uno. Nuestros resultados sugieren que las cepas Coche y Araya pueden ser potencialmente utilizadas en la biotecnología de producción de carotenoides.Carotenogenesis of five strains of the algae Dunaliella sp

  17. El caso del Outburst Flood histórico de la laguna Derrumbe, Cholila, Chubut: Colapso de dique Morénico en la Cordillera Norpatagónica

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    Bruno Colavitto

    2012-09-01

    Full Text Available La laguna Derrumbe es un cuerpo de agua ubicado en los Andes Norpatagónicos en la provincia de Chubut, Argentina. Está contenida en un circo glaciario y endicada por una morena frontal del glaciar homónimo. A través del reconocimiento de campo se pudo describir a esta laguna y a un importante depósito rocoso que se halla aguas abajo de la misma, interpretado como un depósito de outburst flood. Estos depósitos son generados por procesos de alta energía relacionados con la rotura de un dique natural, en este caso un dique morénico. El estudio realizado permitió concluir que la morena frontal del glaciar Derrumbe sufrió una rotura parcial en tiempos históricos, desatando así una inundación súbita aguas abajo de la laguna, a través del valle del río Tigre, en la localidad de Cholila. En este trabajo se analizaron las posibles causas que dieron lugar a la rotura, la cual probablemente sea producto del rápido retroceso que el glaciar experimentó durante la década del ´50 y principios del ´60. Retroceso comparable con el ocurrido en muchos de los cuerpos glaciares de los Andes Patagónicos durante el último siglo.

  18. La influencia del régimen hídrico sobre las comunidades de macrófitos de lagunas someras de la Depresión del Duero

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    Margarita Fernández Aláez

    2004-01-01

    Full Text Available En la Depresión del Duero, caracterizada por condiciones de semiaridez, se encuentra la mayor cantidad y variedad de sistemas palustres españoles. En este conjunto, son de una gran singularidad las pequeñas lagunas someras, generalmente poco mineralizadas, asentadas sobre formaciones de rañas. Uno de los aspectos más interesantes del funcionamiento de estos sistemas acuáticos está relacionado con los ritmos de inundación. Los niveles del agua fluctúan intra e interanualmente, dependiendo en gran parte de las condiciones climáticas de la región, y afectando significativamente al desarrollo de las comunidades de macrófitos. La duración de la inundación, la regularidad de este proceso en el tiempo y la superficie de la laguna, que afectan a la disponibilidad y uso diferencial de los recursos y a la heterogeneidad, controlan la riqueza de especies, la abundancia y la distribución de los macrófitos en las lagunas del sureste de León. Además, las condiciones meteorológicas y el régimen hídrico ejercen una fuerte influencia sobre el modelo estacional y las diferencias interanuales en la biomasa de macrófitos sumergidos.

  19. Study and characterization of noble metal deposits on similar rusty surfaces to those of the reactor U-1 type BWR of nuclear power station of Laguna Verde; Estudio y caracterizacion de depositos de metales nobles sobre superficies oxidadas similares a las del reactor de la Central de Laguna Verde (CNLV) U1 del tipo BWR

    Energy Technology Data Exchange (ETDEWEB)

    Flores S, V. H.

    2011-07-01

    In the present investigation work, were determined the parameters to simulate the conditions of internal oxidation reactor circulation pipes of the nuclear power plant of Laguna Verde in Veracruz. We used 304l stainless steel cylinders with two faces prepared with abrasive paper of No. 600, with the finality to obtain similar surface to the internal circulation piping nuclear reactor. Oxides was formed within an autoclave (Autoclave MEX-02 unit B), which is a device that simulates the working conditions of the nuclear reactor, but without radiation generated by the fission reaction within the reactor. The oxidation conditions were a temperature of 280 C and pressure of 8 MPa, similar conditions to the reactor operating in nuclear power plant of Laguna Verde in Veracruz, Mexico (BWR conditions), with an average conductivity of 4.58 ms / cm and 2352 ppb oxygen to simulate normal water chemistry NWC. Were obtained deposits of noble metal oxides formed on 304l stainless steel samples, in a 250 ml autoclave at a temperature range of 180 to 200 C. The elements that were used to deposit platinum-rhodium (Pt-Rh) with aqueous Na{sub 2}Pt (OH){sub 6} and Na{sub 3}Rh (NO{sub 2}){sub 6}, Silver (Ag) with an aqueous solution of AgNO{sub 3}, zirconium (Zr) with aqueous Zr O (NO{sub 3}) and ZrO{sub 2}, and zinc (Zn) in aqueous solution of Zn (NO{sub 3}){sub 2} under conditions of normal water chemistry. Also there was the oxidation of 304l stainless steel specimens in normal water chemistry with a solution of Zinc (Zn) (NWC + Zn). Oxidation of the specimens in water chemistry with a solution of zinc (Zn + NWC) was prepared in two ways: within the MEX-02 autoclave unit A in a solution of zinc and a flask at constant temperature in zinc solution. The oxides formed and deposits were characterized by scanning electron microscopy, energy dispersive X-ray analysis, elemental field analysis and X-ray diffraction. By other hand was evaluated the electrochemical behavior of the oxides

  20. Indice fisicoquímico de la calidad de agua para el manejo de lagunas tropicales de inundación

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    Ana Gabriela Pérez-Castillo

    2008-12-01

    Full Text Available Se creó un índice fisicoquímico de calidad del agua (ICA-L, para lagunas que se desbordan, el cual fue validado en el sector de riego de Tamarindo, y en una sección del sistema de lagunas del Parque Nacional Palo verde (Guanacaste, Costa Rica. El índice incluye las variables: porcentaje de saturación de oxígeno disuelto, pH, concentración de nitratos, concentración de fósforo total, demanda química de oxígeno, concentración de sólidos suspendidos, conductividad eléctrica y temperatura. El índice se fija automáticamente en cero si la concentración de alguna sustancia tóxica excede el máximo permitido. Los factores de ponderación se ajustaron con base en los pesos definidos en el Índice de Calidad de Agua de la National Sanitation Foundation (ICA-NSF, se excluyó el peso del conteo de coliformes fecales, se integró la ponderación de turbiedad y de sólidos totales una sola, de sólidos suspendidos, y se asignó a la conductividad un factor de 0.08. El índice per-mite evaluar la capacidad del agua de las lagunas tropicales de inundación de agua dulce, para lograr el sostenimiento de la biodiversidad y el desarrollo de la vida acuática, cuando surgen peligros por prácticas agropecuarias.Physicochemical water quality index, a management tool for tropical-flooding lagoons. We propose ICA-L, a wetland physicochemical water quality index (WWQI, to be used as a management tool for seasonal-flooding lagoons in Palo verde National Park, Guanacaste, Costa Rica. The goal is to preserve their natural role for native plants as well as migrants and local animal species. The index was developed in four steps: parameter selection, assignment of parameter weight, transformation of data to their corresponding sub indices and selection of an appropriate aggregation function. In this process, the following criteria were used as a reference: WQI from the National Sanitation Foundation, WQI for the Des Moines River, Escribano and De Frutos

  1. Efecto de clausuras de ganado en la recuperación de la vegetación en el Parque Nacional Laguna Blanca

    Directory of Open Access Journals (Sweden)

    Luciana Inés Escobar

    2013-06-01

    Full Text Available El objetivo de este estudio fue analizar los efectos de la exclusión de ganado sobre la vegetación de tres ambientes del Parque Nacional Laguna Blanca (PNLB: un sector de estepa graminoso-arbustiva, un borde de laguna y un área de mallín. En ellos se comparó la composición florística, la riqueza y cobertura de especies dentro y fuera de las clausuras. Se evaluó el nivel de herbivoría mediante una escala semi-cuantitativa, y se midió el grado de compactación del suelo utilizando un penetrómetro de golpes. Las 276 especies presentes en el Parque corresponden a 56 familias (destacándose Asteraceae, Poaceae y Fabaceae y representan dos grandes grupos funcionales: herbáceas (73,6% y leñosas (26,3%. El 15% del total son exóticas, y su presencia se relaciona con el uso pastoril de las tierras. La diversidad en la composición vegetal del Parque es alta debido a la variedad de ambientes que allí existen, donde contrariamente a la cobertura, la riqueza de especies fue mayor en el sector estepario y menor en el mallín. La tendencia general es la de mayor riqueza y cobertura en el interior de las clausuras. El mayor impacto de herbivoría es producido por ganado ovino y caprino, debido a su amplia y versátil dieta como a la preferencia por el consumo de especies palatables, aunque la compactación del suelo fue significativa afuera de la clausura del sector estepario.Los resultados obtenidos mostraron la exitosa recuperación de la cobertura vegetal dentro de las clausuras contra ganado, poniendo de manifiesto la capacidad productiva de este ecosistema. Esto sugiere que un mediante riguroso control de la carga animal, aún existe una buena probabilidad de regeneración de las condiciones naturales características de este medio ambiente. 

  2. La formación en competencias de la biblioteca de la Universidad de La Laguna en el contexto de la cooperación universitaria

    Directory of Open Access Journals (Sweden)

    Hernández, Carmen Julia

    2012-07-01

    Full Text Available This paper deals with the experience of the Library of the University of La Laguna since 2006-2007, when it began to change its model of user training for a new one based on information competences, in line with the requirements of the new European Higher Education Area. It analyzes what this change has meant from the point of view of planning a new training program and the acquisition of new competences by the librarian staff in order to help users acquire information management skills, abilities and behaviours that can be applied in their academic, professional and personal lives. It also describes cooperation with other university libraries, in the framework of an agreement signed in 2010. The aim of this agreement is for our model to be shared for training new students and subsequently evaluating it through a comparison of results from the different universities. Finally, it deals with the collaboration between librarians and professors for including information competence training in course guides.

    Se recoge la experiencia de La Biblioteca de la Universidad de La Laguna desde el curso 2006-2007, en el que comienza a cambiar su modelo de formación de usuarios por otro basado en formación en competencias, en consonancia con los requisitos que el nuevo entorno educativo recogía. Se analiza lo que ha significado dicha transformación desde el punto de vista de la planificación de un nuevo programa formativo y la adquisición de nuevas competencias por parte de los bibliotecarios para ayudar a los usuarios a conseguir unas destrezas, habilidades y conductas transferibles a su vida académica y personal, y a su futuro laboral en relación con la gestión de información. También se aborda el significado de trabajar de forma cooperativa con otras bibliotecas universitarias, como resultado de la firma de un convenio en el año 2010 con el objetivo de compartir nuestro modelo de formación para alumnos de nuevo ingreso y evaluarlo

  3. Sesgos de género en la educación científico-tecnológica: el caso de la Universidad de La Laguna

    Directory of Open Access Journals (Sweden)

    García, Rosana

    2008-10-01

    Full Text Available In this article are presented the results of a study about the existence of gender biases in the scientific-technological education. In this study we expect to demonstrate with data the existence of gender stereotyped beliefs in university and high school teachers of science and technology. This way, we wants to point out if what certain scientific disciplines affirm about the cognitive capacities, abilities, attitudes and women’s behaviors are transmitted in the teaching of the science and the technology, and if the gender biases characteristic of these disciplines are thus perpetuated through the education of the new scientifics and technologist generations. This study has been made at the University of La Laguna and the highs schools of Tenerife, but we believe that its results could be generalized to other Spanish universities and high schools.En este artículo se presentan los resultados de un estudio sobre la existencia de sesgos de género en la educación científico-tecnológica. En él se pretende demostrar con datos la existencia de creencias estereotipadas acerca de los géneros en el profesorado de ciencia y tecnología de la universidad y de la enseñanza secundaria. De esta manera se quiere establecer si lo que afirman ciertas disciplinas científicas acerca de las capacidades cognitivas, destrezas actitudes y comportamientos de las mujeres se transmite en la enseñanza de la ciencia y la tecnología, y si se perpetúan así los sesgos de género presentes en estas disciplinas a través de la formación de las nuevas generaciones de científicos/as y tecnólogos/as. Este estudio se ha realizado en la Universidad de La Laguna y los institutos de enseñanza secundaria de Tenerife, pero creemos que los resultados obtenidos podrían ser generalizados a las universidades e institutos del resto de España.

  4. El impacto de la desecación de la laguna de Lerma en la gastronomía lacustre de San Pedro Tultepec de Quiroga, Estado de México

    Directory of Open Access Journals (Sweden)

    Felipe Carlos Viesca González

    2011-01-01

    Full Text Available El objetivo de este trabajo es caracterizar la gastronomía lacustre en el Alto Lerma, prevaleciente antes y después de la desecación de la Laguna de Lerma, específicamente la de San Pedro Tultepec de Quiroga municipio de Lerma, en el Estado de México. Mediante la aplicación de la técnica etnográfica en la realización de la investigación de campo, se identificaron y localizaron a 30 personas adultas que aún entran a la laguna de Chimaliapan o Lerma, o que tienen conocimiento sobre los ingredientes lacustres y las preparaciones culinarias elaboradas con ellos. Además se realizaron visitas a los mercados locales e incursiones en la laguna y áreas aledañas con la guía de lugareños conocedores del entorno, con el fin de obtener información sobre estos productos. Se encontró que todavía se recolectan especies vegetales como nopales, hongos, papas de agua o apacloles y quelites, entre ellos berros o tiernitos y quintoniles. Asimismo, se aprovechan especies animales como patos, carpas, atepocates, ranas, acociles y ajolotes. Menos del 1% de la población estudiada aún elabora platillos basados en ingredientes extraídos de la laguna. Se preparan tamales de pescado, rana o carpa, acociles, hueva de carpa, carpas y patos de diversas maneras, chile relleno de támbulas y atepocates, y ranas empanizadas o fritas. Con base en lo anterior, se concluye, que a pesar de estar contaminada, todavía se extrae de la laguna de Chimaliapan una gran variedad de flora y fauna que se emplea para la alimentación, lo cual indica que estos recursos bióticos son una importante fuente para muchas familias, y que tienen un "buen potencial" de aprovechamiento.

  5. Simulation of the steady state of the Laguna Verde Nuclear power station at full power (1931 MWt and 2027 Mwt) with the SCDAPSIM code; Simulacion del estado estacionario de la Central Nucleoelectrica de Laguna Verde a plena potencia (1931 MWt y 2027 MWt) con el codigo SCDAPSIM

    Energy Technology Data Exchange (ETDEWEB)

    Amador G, R.; Nunez C, A.; Mateos, E. del A. [Comision Nacional de Seguridad Nuclear y Salvaguardias, Mexico D.F. (Mexico)

    2001-07-01

    This document describes two models developed for the Laguna Verde Nuclear Power Station (LVNPP) using SCDAPSIM computer code. These models represent the LVNPP in normal operation with a nominal power of 1931 MWt and power uprate conditions of 2027 MWt. The steady states obtained by means of these models comply with the criteria established by the ANSI/ANS-3.5-1985 for nuclear power plant simulators. This criteria has been applied to the models of the LVNPP developed by CNSNS in want of some international accepted criteria for ''Best Estimation'' computer codes. These models will be the bases to carry out studies of validation of the own models as well as the analysis of diverse scenarios that evolve to a severe accident. (Author)

  6. Estructura y composición florística de la vegetación del Parque Educativo Laguna Bélgica, Chiapas, México Structure and floristic composition of vegetation on Parque Educativo Laguna Bélgica, Chiapas, Mexico

    Directory of Open Access Journals (Sweden)

    Ma. Consuelo Escobar-Ocampo

    2007-12-01

    Full Text Available El estudio se realizó en el Parque Educativo Laguna Bélgica (PELB. El objetivo fue el de caracterizar las asociaciones vegetales para sentar las bases para su manejo y conservación. El mapa de vegetación se realizó con la interpretación de ortofotos, verificaciones de campo y un Sistema de Información geográfica. La caracterización de la vegetación y los inventarios de flora leñosa se elaboraron según el método de Mueller-Dombois y Ellenberg. Se censaron todas las leñosas con altura > 1 m y diámetro a la altura del pecho > 3 cm. La cobertura se evaluó cualitativamente. Se reconocieron 5 asociaciones vegetales: encinar de Quercus oleoides, encinar de Q. elliptica, acahual arbóreo, pastizal y asociación secundaria de herbáceas. En la zona de estudio se colectaron 159 especies, las cuales se complementaron mediante revisión bibliográfica obteniéndose un total de 254 especies, comprendidas en 157 géneros y 64 familias. Se aportan 68 nuevos registros para el PELB. La flora de Laguna Bélgica presenta una mayor afinidad florística con los bosques húmedos de la vertiente del golfo que con los de la depresión central. Se resalta la alta diversidad florística y la importancia por conservar y manejar este relicto de vegetación.The study was conducted in the Parque Educativo Laguna Bélgica (PELB. The objective was to characterize the vegetal associations to establish basis for management. The vegetation map was elaborated on interpretation of ortophotos, supported with field verification and processed using a GIS. The characterization of the vegetation used the method of Mueller-Dombois and Ellenberg. For forest inventories we registered woody species > 1 m height and > 3 cm diameter breast height. The coverage was evaluated in qualitative form based on Braun-Blanquet method. Five types of vegetal associations were recognized: oak forest of Quercus oleoides, oak forest of Q. elliptica, tree-secondary vegetation, grasslands, and

  7. Revision of documents guide to obtain the renovation of licence of the nuclear power plant of Laguna Verde, Units I and II; Revision de documentos guia para obtener la renovacion de licencia de la Central Nuclear Laguna Verde Unidades 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    Jarvio C, G. [ININ 52750 La Marquesa, Estado de Mexico (Mexico); Fernandez S, G. [CFE, Gerencia de Centrales Nucleoelectricas, Subgerencia de Ingenieria, Carretera Veracruz-Medellin s/n (Km. 7.5), Dos Bocas, 54270 Veracruz (Mexico)]. e-mail: giarvio@yahoo.com.mx

    2008-07-01

    Unquestionably the renovation of license of the nuclear power plants , it this converting in a promising option to be able to gather in sure, reliable form and economic those requests about future energy in the countries with facilities of this type. This work it analyzes four documents guide and their application for the determination of the renovation of it licenses in nuclear plants that will serve of base for their aplication in the Nuclear Power Plant of Laguna Verde Units I and 2. The four documents in question are: the one Inform Generic of Learned Lessons on the Aging (NUREG - 1801), the Standard Revision Plan for the Renovation of License (NUREG - 1800), the Regulatory Guide for Renovation of License (GR-1.188), and the NEI 95-10, developed by the Institute of Nuclear Energy that is an Industrial Guide to Implement the Requirements of the 1OCFR Part 54-the Rule of Renovation of It licenses. (Author)

  8. Methodology of aging management in structures, systems and components of a nuclear power plant and its application to a pilot program in Laguna Verde; Metodologia de la gestion del envejecimiento en estructuras, sistemas y componentes de una central nuclear y su aplicacion a un programa piloto en Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Jarvio C, G. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Fernandez S, G. [Comision Federal de Electricidad, Gerencia de Centrales Nucleoelectricas, Subgerencia de Ingenieria, Carretera Veracruz-Medellin Km. 7.5, Dos Bocas, 54270 Veracruz (Mexico)], e-mail: gfdezs@cfe.gob.mx

    2009-10-15

    From its origin the nuclear power plants confront the effects of time and of environment, giving as result the aging of its structures, systems and components. In this document the general process is described for the establishment of Aging Management Program developed by IAEA. Following the program methodology is guaranteed that a nuclear power plant manages the aging effects appropriately and to make decisions for its solution, assuring the characteristic functions of structures, systems and components of same nuclear power plant. On the other hand, the implantation of an aging management program constitutes the base for development of a licence renovation program, like it can be the specific case of the Central Laguna Verde Units 1 and 2. (Author)

  9. Analysis of the micro-structural damages by neutronic irradiation of the steel of reactor vessels of the nuclear power plant of Laguna Verde. Characterization of the design steel; Analisis de los danos micro-estructurales por irradiacion neutronica del acero de la vasija de los reactores de la Central Nuclear de Laguna Verde. Caracterizacion del acero de diseno

    Energy Technology Data Exchange (ETDEWEB)

    Moranchel y Rodriguez, M.; Garcia B, A. [IPN, Escuela Superior de Fisica y Matematicas, Departamento de Fisica, Av. Luis Enrique Erro s/n, Unidad Profesional Adolfo Lopez Mateos, Col. Lindavista, 07738 Mexico D. F. (Mexico); Longoria G, L. C., E-mail: mmoranchel@ipn.m [ININ, Direccion de Investigacion Cientifica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-09-15

    The vessel of a nuclear reactor is one of the safety barriers more important in the design, construction and operation of the reactor. If the vessel results affected to the grade of to have fracture and/or cracks it is very probable the conclusion of their useful life in order to guarantee the nuclear safety and the radiological protection of the exposure occupational personnel, of the public and the environment avoiding the exposition to radioactive sources. The materials of the vessel of a nuclear reactor are exposed continually to the neutronic irradiation that generates the same nuclear reactor. The neutrons that impact to the vessel have the sufficient energy to penetrate certain depth in function of the energy of the incident neutron until reaching the repose or to be absorbed by some nucleus. In the course of their penetration, the neutrons interact with the nuclei, atoms, molecules and with the same crystalline nets of the vessel material producing vacuums, interstitial, precipitate and segregations among other defects that can modify the mechanical properties of the steel. The steel A533-B is the material with which is manufactured the vessel of the nuclear reactors of nuclear power plant of Laguna Verde, is an alloy that, among other components, it contains atoms of Ni that if they are segregated by the neutrons impact this would favor to the cracking of the same vessel. This work is part of an investigation to analyze the micro-structural damages of the reactor vessels of the nuclear power plant of Laguna Verde due to the neutronic irradiation which is exposed in a continuous way. We will show the characterization of the design steel of the vessel, what offers a comprehension about their chemical composition, the superficial topography and the crystalline nets of the steel A533-B. It will also allow analyze the existence of precipitates, segregates, the type of crystalline net and the distances inter-plains of the design steel of the vessel. (Author)

  10. Diversidad de géneros de hongos del suelo en tres campos con diferente condición agrícola en La Laguna, México Diversity of soil fungi genera in three different condition agricultural fields in La Laguna, Mexico

    Directory of Open Access Journals (Sweden)

    José Alfredo Samaniego-Gaxiola

    2007-12-01

    Full Text Available En La Laguna, Coahuila-Durango, México (zona con una precipitación anual entre 80 a 250 mm se estudió la estructura de géneros de hongos del suelo en 3 campos de cultivo agrícola. Del suelo de Tierra Blanca, una huerta de nogal de 51 años, fueron aislados 23 géneros de hongos y de otros 2 suelos, una huerta de nogal de 14 años, nombrada El Chupón y un campo con cultivo de alfalfa, denominado San Jorge, se aislaron l2 géneros. Para cada género se calculó su valor índice de ímportancia (V I I. El género Fusarium tuvo el mayor V I I en los 3 suelos estudiados (71-98. La diversidad (calculada con el índice de Shannon de géneros fue diferente para cada suelo de acuerdo con intervalos de confianza (95%, con valores de 1.89, 1.72 y 1.19 para Tierra Blanca, El Chupón y San Jorge, respectivamente. Se calcularon índices ecológicos adicionales, como, Simpson, máxima riqueza (H' max y regularidad (J'. Los valores del índice de Simpson y de J' fueron similares en Tierra Blanca y San Jorge, pero sólo H' max fue similar entre El Chupón y San Jorge. El índice de similitud de Shøresen fue igual al comparar Tierra Blanca con El Chupón o Tierra Blanca con San Jorge (51.4, pero distinto entre el Chupón y San Jorge (58.3. El índice β para las combinaciones Tierra Blanca vs. San Jorge y Tierra Blanca vs. El Chupón fueron de 0.43, pero para San Jorge vs. El Chupón fue de 0.83. Los géneros de hongos del suelo que se encontraron en La Laguna coinciden en 67-75% con los encontrados en suelos desérticos de Israel, pero en La Laguna la estructura de los géneros de hongos es distinta; aquí domina Fusarium y aparecen nuevos géneros, como Trichoderma. Los cambios en la micobiota del suelo pueden haber ocurrido por la actividad agrícola en los últimos 50 años.This study was carried out in agricultural soils in La Laguna, Coahuila - Durango, Mexico (annual precipitation 80-250 mm. The structure of soil fungal genera of three field soil

  11. ANÁLISIS DE LA CALIDAD DEL AGUA EN LAS LAGUNAS DE BUSTILLOS Y DE LOS MEXICANOS (CHIHUAHUA, MÉXICO

    Directory of Open Access Journals (Sweden)

    Jesús Pilar Amado Álvarez

    2016-01-01

    Full Text Available En la parte central del estado de Chihuahua (México se encuentra la cuenca de drenaje que alimenta las lagunas endorreicas de Bustillos, y de los Mexicanos. Estos humedales de especial interés ambiental, se encuentran amenazados por una fuerte presión de actividades humanas. Para este trabajo se han planteado una serie de análisis químicos, físicos y microbiológicos, que determinan unos elevados índices de contaminación en estos hábitats acuáticos. Los resultados han mostrado bajos índices de oxígeno disuelto y elevadas concentraciones en nitratos y bacterias coliformes en el agua. Se ha detectado que las principales fuentes de contaminación de estos recursos hídricos son las actividades agropecuarias, los vertidos de aguas residuales de las áreas urbanas y, en mayor medida, por los desechos de los tratamientos industriales.

  12. Diameter at breast height estimation in Mt. Makiling, Laguna, Philippines using metrics derived from airborne LiDAR data and Worldview-2 bands

    Science.gov (United States)

    Tandoc, Fe Andrea M.; Paringit, Enrico C.; Bantayan, Nathaniel C.; Argamosa, Reginald Jay L.; Faelga, Regine Anne G.; Ibañez, Carlyn Ann G.; Posilero, Mark Anthony V.; Zaragosa, Gio P.; Malabanan, Matthew V.

    2016-05-01

    Airborne LiDAR is fast becoming an innovation for forest inventory. It aids in obtaining forest characteristics in areas or cases where actual field inventory would be very tedious. This study aims to estimate diameter at breast height (DBH) using airborne LiDAR point-cloud parameters with Worldview-2 satellite images, and to validate these with actual measurements done in the field. The study site is a field plot with forest inventory at Mt. Makiling, Laguna, Philippines that was surveyed into 20m, 10m and 5m subplots or grids. The estimation of DBH was carried out by extracting the said parameters from the LiDAR point-cloud, and extracting different bands from the Worldview image and performing linear and log-linear regression of these values. The regressions were done in four different cases, namely: LiDAR parameters without intensity (case1), LiDAR parameters without intensity with Worldview bands (case 2), intensity of LiDAR points (case 3), and LiDAR parameters with intensity and Worldview bands (case 4). From these it was found that the best case for estimating DBH is with the use of LiDAR parameters with intensity and Worldview bands in a 10x10 grid, in Log-Linear regression with a root mean squared error of 1.96 cm and an adjusted R2 value of 0.65. This was further improved through stepwise regression, and adjusted R2 value was 0.71.

  13. Holocene Amazon rainforest-savanna dynamics and climatic implications: high-resolution pollen record from Laguna Loma Linda in eastern Colombia

    Science.gov (United States)

    Behling, Hermann; Hooghiemstra, Henry

    2000-10-01

    We present a high-resolution pollen record of a 695-cm-long sediment core from Laguna Loma Linda, located at an altitude of 310 m in the transitional zone between the savannas of the Llanos Orientales and the Amazonian rainforest, about 100 km from the Eastern Cordillera. Based on eight AMS 14C ages, the record represents the last 8700 14C yr BP. During the period from 8700 to 6000 14C yr BP the vegetation was dominated by grass savanna with only a few woody taxa, such as Curatella and Byrsonima, present in low abundance. Gallery forest along the drainage system apparently was poorly developed. Compared with today, precipitation must have been significantly lower and seasonality stronger. During the period from 6000 to 3600 14C yr BP, rainforest taxa increased markedly, reflecting an increase in precipitation. Rainforest and gallery forest taxa such as Moraceae/Urticaceae, Melastomataceae, Alchornea, Cecropia and Acalypha, were abundant, whereas Poaceae were reduced in frequency. From 3600 to 2300 14C yr BP rainforest taxa continued to increase; Moraceae/Urticaceae became very frequent, and Myrtaceae and Myrsine became common. Savanna vegetation decreased continuously. We infer that precipitation was still increasing, and that the length of the annual dry period possibly shortened. From 2300 14C yr BP onwards, grass savanna (mainly represented by Poaceae) expanded and Mauritia palms became frequent. This reflects increased human impact on the vegetation.

  14. Análisis morfológico de escarpas asociadas a una falla de intraplaca con actividad cuaternaria: falla Las lagunas, Córdoba

    Directory of Open Access Journals (Sweden)

    Diego Villalba

    2014-03-01

    Full Text Available El objetivo de la presente contribución es, mediante el análisis cuantitativo de la morfología de escarpas de falla desarrolladas sobre sedimentos cuaternarios, estimar las edades de las reactivaciones prehistóricas e históricas de la falla Las Lagunas. El área de estudio se ubica al SO del departamento Río Cuarto, en el sector pedemontano de la sierra de Comechingones entre las localidades de Achiras y Sampacho, a 33° 18' S y 64° 49´ O, región central de Argentina. El análisis morfológico cuantitativo se realizó mediante la obtención de perfiles topográficos de detalle transversales a la traza de la estructura y la aplicación de curvas de regresión para determinar sus edades. Esto permitió interpretar que las evidencias de deformación mecánica, ruptura en superficie, corresponden a, al menos, cuatro fuertes terremotos asociados a esta falla con ocurrencia en los últimos 10 ka. Con esta información se elaboró una curva de aproximación característica para rupturas en superficie, asociadas a esta falla, de edades menores o iguales a 100 años.

  15. COMPETENCIAS DIGITALES DEL PROFESORADO Y ALUMNADO EN EL DESARROLLO DE LA DOCENCIA VIRTUAL. EL CASO DE LA UNIVERSIDAD DE LA LAGUNA

    Directory of Open Access Journals (Sweden)

    Ma Belén San Nicolás

    2012-01-01

    Full Text Available En este artículo se ofrecen algunos resultados de un estudio empírico desarrollado en la Universidad de La Laguna (España con la finalidad de conocer los usos que el alumnado y el profesorado universitario hace de las TIC e indagar acerca de su influencia en los procesos de enseñanza y aprendizaje virtual en la educación superior. Para el desarrollo de este estudio se crearon dos cuestionarios independientes en el que participaron un total de 1561 estudiantes y206 profesores. En el presente documento se aborda solo una parte de este estudio centrándose específicamente en la dimensión de uso de las TIC o competencia digital de profesores y estudiantes, donde se recoge información sobre actividades de búsqueda de información; desarrollo de procesos comunicacionales (consultar el correo electrónico, participar en foros, mensajería instantánea, usar redes sociales; elaboración de tareas (usar distintos paquetesofimáticos, manejar programas de retoque de en la web (editar páginas web personal, gestionar imágenes, utilizar programas de manipulación y dinamizar otras páginas web, escribir en blogs.

  16. Monitoreo de una formación deltaica reciente en un humedal costero tropical utilizando imágenes aeroespaciales y sig. Caso delta del río Guapo, laguna de Tacarigua, Venezuela

    Directory of Open Access Journals (Sweden)

    Argelia Calzadilla Pérez

    2003-01-01

    Full Text Available Un enfoque integrado del uso de imágenes aeroespaciales y SIG fue aplicado en el ‘monitoreo’ de un proceso acelerado de formación deltáica en la Laguna de Tacarigua, un humedal costero de manglar localizado en la costa norcentral de Venezuela. Recientemente, el reconocimiento del valor como recurso económico de humedales costeros tales como lagunas costeras y deltas, ha traído como consecuencia la necesidad de proteger y conservar estos ecosistemas. Con ese fin, estas áreas costeras deben ser continuamente “monitoreadas” de tal manera que los cambios temporales en su ambiente puedan ser analizados. Determinar la causa, extensión y distribución espacial de estos cambios, podría contribuir en etapas posteriores en muchos aspectos de la calidad ambiental, análisis de compatibilidad y conflictos del uso de la tierra, y, en general, en el diseño de planes para un manejo más racional de los recursos. Mediante el uso integrado de información aeroespacial y un levantamiento de campo, se estudió la formación del delta del río Guapo dentro de la Laguna de Tacarigua y se ‘mapeó’ la expansión que este ambiente deposicional ha venido sufriendo. Un set histórico de fotografías aéreas y una imagen de radar, conjuntamente con el chequeo de campo, sirvieron de base para evaluar el crecimiento del delta desde su formación, hasta el presente.

  17. Comunidades de insectos acuáticos de charcos temporarios y lagunas en la ciudad de Buenos Aires (Argentina Aquatic insect communities of temporary pools and permanent ponds in Buenos Aires City (Argentina

    Directory of Open Access Journals (Sweden)

    María S. Fontanarrosa

    2004-12-01

    Full Text Available Se realizó un estudio comparativo de la comunidad de insectos acuáticos presente en charcos temporarios de parques y plazas de la ciudad de Buenos Aires, y en lagunas permanentes de la Reserva Ecológica Costanera Sur, situada en la ribera del Río de la Plata. Se revisaron 3436 charcos y se visitaron, en 149 oportunidades, seis lagunas de la reserva. Para el conjunto de ambientes, se registraron 85 taxones pertenecientes a cinco órdenes de insectos. Los coleópteros fueron los más diversos (36 taxones, seguidos por los dípteros (27, heterópteros (17, odonatos (4 y efemerópteros (1. Se observaron altos valores de riqueza en los charcos temporarios (58 taxones y las lagunas sin vegetación flotante (64 taxones. La diversidad estimada de los charcos temporarios fue significativamente (pWe studied the community of aquatic insects inhabiting both temporary pools and permanent ponds occuring in Buenos Aires City. A total of 3436 rain pools were examined, and six permanent ponds at the "Reserva Ecológica Costanera Sur" in the Río de la Plata riverside were visited 149 times. A total of 85 taxa were recorded from both habitats, included in five orders of Insecta. The order Coleoptera showed the highest diversity values (36 taxa, followed by Diptera (27, Heteroptera (17, Odonata (4, and Ephemeroptera (1. High values of richness were observed in temporary pools (58 taxa and permanent ponds without floating vegetation (64 taxa. The diversity index for temporary ponds was significantly (p<0,05 lower than in permanent habitats.

  18. Paleoecología del Holoceno en la Gran Sabana, SE Venezuela: Análisis preliminar de polen y microcarbones en la Laguna Encantada

    Directory of Open Access Journals (Sweden)

    Montoya, E.

    2009-12-01

    Full Text Available The Gran Sabana region (SE Venezuela is characterized by extensive neotropical savannas, in a warm and wet climate, apparently more suitable for the existence of rain forests. Two main types of hypotheses have been proposed to explain this situation: natural factors, such as climate changes or soil poverty, and burning by humans. This study analyzes the pollen and charcoal content of a 7,500 years old peat bog, at the shore of Laguna Encantada. The savanna landscape has dominated the area during the whole interval, but local fi res did not appear until around 1,200 years ago, when the present communities began to establish. An expansion of gallery forests, likely due to a climatic shift, has been recorded around 4,000 years ago, followed by a deforestation triggered by fire, leading to present-day situation. These results, together with former similar studies, suggest that the present Gran Sabana landscape resulted from the interaction of diverse factors, being climate changes more related to its origin and human induced fires more linked to the recent expansion.

    La región de la Gran Sabana, al SE de Venezuela, se caracteriza por la presencia de extensas sabanas neotropicales, en un clima cálido y húmedo, que parece más propicio para la existencia de bosques húmedos. Existen dos grandes grupos de hipótesis para explicar esta configuración vegetal: las naturales (cambios climáticos, pobreza de suelos y las antrópicas (incendios provocados. El presente estudio utiliza el análisis de polen y microcarbones para reconstruir las tendencias paleoambientales, de la vegetación y del régimen de incendios, en la turbera litoral de la Laguna Encantada, durante los últimos 7.500 años. Las sabanas han dominado el paisaje durante todo este tiempo, a pesar de que los incendios locales no afectaron el área hasta hace unos 1.200 años, momento en el cual se establecen las comunidades actuales. Hacia los 4.000 años antes del presente tuvo

  19. Composición por tallas, edad y crecimiento de Litopenaeus vannamei (Natantia: Penaeidae, en la laguna Mar Muerto, Oaxaca-Chiapas, México

    Directory of Open Access Journals (Sweden)

    Sebastián Ramos-Cruz

    2000-12-01

    Full Text Available De mayo a noviembre de 1996 se muestreó la captura comercial de camarón blanco (L. vannamei en la laguna Mar Muerto, localizada entre los estados de Oaxaca y Chiapas, México. Con la finalidad de conocer el crecimiento de esta especie en el interior de este sistema lagunar se registraron las tallas y pesos individuales de 16,378 camarones que en conjunto pesaron 68,645 g. Las tallas observadas fluctuaron entre 11 y 145 mm de longitud total, con pesos entre 0.1 y 26.3 g. La talla media mínima de reclutamiento a la fase explotada es de 45 mm. Los organismos abandonan el sistema lagunar para reclutarse a la zona marina con una talla que varía entre 83 y 120 mm, con una edad de1.5 a 4.5 meses. Con el análisis de progresión modal se detectaron 13 generaciones en el interior de la laguna. Las tasas de crecimiento fluctuaron entre 0.13 y 1.27 mm/día con un valor medio de 0.64 mm/día. Las longitudes asintóticas estimadas para cada generación variaron entre 105 y 159 mm, ubicándose la talla media en 136 mm, mientras que el peso asintótico medio fue de 15 g, con valores extremos de 8 y 23 g. Los parámetros del modelo de crecimiento de von Bertalanffy son: L = 136 mm, P = 15 g, k = 0.0161 mm y to = 5 mm. Tanto L como P no representan, al menos en este caso, las tallas y pesos asintóticos que la especie alcanza dentro del sistema lagunar, sino que deben de interpretarse como las tallas y pesos medios que debieran tener los organismos al momento de abandonarlo.The commercial catches of white shrimp Litopenaeus vannamei were sampled (May through November 1996 in the Mar Muerto lagoon located between Oaxaca and Chiapas states, Mexico. To measure it’s growth rate at the innermost portions of this system, 16 378 length and weight records were obtained. Length fluctuated between 11 and 145 mm, and weights between 0.1 and 26.3 g. The minimum mean size for recruitment to the exploited phase is 45 mm. Organisms leave the lagunar system for

  20. Estudios de interés tafonómico en los restos óseos humanos de Laguna Tres Reyes 1 (Partido de Adolfo Gonzales Chaves, provincia de Buenos Aires)

    OpenAIRE

    González, Mariela Edith

    2017-01-01

    En este trabajo se presentan los resultados del análisis de los efectos tafonómicos del registro bioarqueológico del sitio Laguna Tres Reyes 1 (Partido de Adolfo Gonzales Chaves), realizado en el marco de la tesis de licenciatura. La metodología consistió en el examen macroscópico de la superficie cortical de cada elemento esqueletal sobre el conjunto de entierros primarios. Las variables analizadas fueron: marcas de raíces, depositación química (carbon...

  1. Analysis of the documents about the core envelopment of nuclear reactor at the Laguna Verde U-1 power plant; Analisis de documentos de los materiales de la envolvente del nucleo del reactor nuclear de la CLV U-1

    Energy Technology Data Exchange (ETDEWEB)

    Zamora R, L.; Medina F, A. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    The degradation of internal components at BWR type reactors is an important subject to consider in the performance availability of the power plant. The Wuergassen nuclear reactor license was confiscated due to the presence of cracking in the core envelopment. In consequence it is necessary carrying out a detailed study with the purpose to avoid these problems in the future. This report presents a review and analysis of documents and technical information referring to the core envelopment of a BWR/5/6 and the Laguna Verde Unit 1 nuclear reactor in Mexico. In this document are presented design data, documents about fabrication processes, and manufacturing of core envelopment. (Author)

  2. A mathematical model; Un modelo matematico para el comportamiento de la radiosensibilidad medida con la viabilidad huevo-adulto de Drosophila melanogaster y D. simulans de Laguna Verde, Veracruz

    Energy Technology Data Exchange (ETDEWEB)

    Castillo M, J.A.; Pimentel P, A.E. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    This work presents the results to define the adult egg viability behavior (VHA) of two species, Drosophila melanogaster and D. simulans obtained with the mathematical model proposed, as well as the respective curves. The data are the VHA result of both species coming from the vicinity of the Laguna Verde Nuclear Power plant (CNLV) comprise a 10 years collect period starting from 1987 until 1997. Each collect includes four series of data which are the VHA result obtained after treatment with 0, 4, 6 and 8 Gy of gamma rays. (Author)

  3. Relevamiento de la ictiofauna de la laguna Camba Cué, isla Apipé Grande, Corrientes, Argentina Ichthyological survey of the Camba Cué lagoon, Apipé Grande Island, Corrientes, Argentina

    Directory of Open Access Journals (Sweden)

    Juan M. Iwaszkiw

    2010-06-01

    Full Text Available La isla Apipé Grande se encuentra a la altura del kilómetro 1400 del río Paraná, dos kilómetros aguas abajo de la represa Yacyretá y actualmente constituye la Reserva Provincial Isla Apipé Grande. Esta isla se destaca por poseer cerca del 70% de la superficie compuesta por zonas bajas e inundables integradas por madrejones, esteros y lagunas. En la zona central de la isla se encuentran las lagunas Hermosa y Cambá Cué que cubren un área aproximada de 300 y 1000 hectáreas respectivamente. En el presente trabajo se informan los resultados del primer relevamiento ictiológico de los referidos cuerpos de agua. La toma de muestras realizada en la laguna Cambá Cué permitió identificar 55 especies de peces. La presencia de especies características de ambientes tanto lóticos como leníticos es interpretada como evidencia de la estrecha relación hidrológica entre estos cuerpos de agua y el sistema del río Paraná.The Apipé Grande island is a Provincial Reserve located in the Paraná river at 1400 km, from its origin at the Buenos Aires harbor, and two km downstream of the Yacyretá Dam. The outstanding feature of the island is that 70% of its area is composed of wetland. At the center of the island there are Hermosa and Cambá Cué «lagunas» with 300 and 1000 hectares respectively. The present paper reports the results of the first ichthyological survey to these water bodies. As a result of the sampling fieldwork 55 fish species were identified. The presence of species belonging to lotic and lenitic environments is interpreted as evidence for the close hydrological relationship of these water bodies and the Paraná river system.

  4. Limnología e ictiofauna de la laguna José María (Córdoba, Argentina, con especial referencia al pejerrey (Odontesthes bonariensis -Valenciennes, 1835-

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    M. Mancini

    2016-09-01

    Full Text Available La región sur de la provincia de Córdoba presenta numerosas lagunas cuyo origen y salinidad varían ampliamente. Muchos de estos ambientes son utilizados para la pesca recreativa del pejerrey (Odontesthes bonariensis. El objetivo del presente trabajo fue caracterizar la calidad del agua y determinar la diversidad del zooplancton y de la ictiofauna con especial referencia a O. bonariensis, de la laguna José María (34º50’17’’S, 63º37’23’’O. Este ambiente se ubica en la cuenca del río Quinto (Córdoba y está comunicado con numerosas lagunas. Se analizaron in situ (n=8, el pH, el oxígeno, la temperatura y transparencia del agua y se tomaron muestras de agua y zooplancton para su análisis en laboratorio. Para la captura de peces se utilizaron redes de enmalle, arrastre, trampa y espineles. La profundidad promedio fue de 1,99 m, con un máximo de 2,20 m. Los registros medios del pH, oxígeno disuelto, temperatura y transparencia fueron 8,51, 9,03 mg/L, 24,3 ºC y 44 cm respectivamente. Por su transparencia, la laguna fue caracterizada como “turbia”. El agua se clasificó como oligohalina (4,09 g/L, sulfatada-sódica y muy dura (484 ppm de CO3Ca. El zooplancton estuvo representado por 3 especies de crustáceos y 7 de rotíferos. Entre los primeros, Metacyclops mendocinus fue el que registró la mayor densidad (162,2 ind/L, mientras que entre los rotíferos fue Brachionus plicatilis con 482,7 ind/L. Se capturaron 12 especies de peces, pertenecientes a 5 órdenes y 9 familias (Shannon = 2,23 bits. El pejerrey fue la especie de mayor abundancia (50,8% y junto al sabalito Cyphocharax voga y la carpa Cyprinus carpio representaron el 85 % del total de biomasa de los peces capturados. Los parámetros poblacionales de O. bonariensis fueron: Peso= 0,0000047081*LEst3,178 (R2=0,99, n=116; longitud total= 5,854+LEst*1,168 (R2= 0,99, n= 117; LEst(t= 489,02 (1-e-0,225(t-0,46 y W(t= 1647,5 (1- e-0,225(t-0,463,177.

  5. Características ecofisiológicas de la reproducción de Nodipecten subnodosus (Sowerby, 1835) (Pectinidae) en la Laguna Ojo de Liebre, B.C.S.

    OpenAIRE

    Arellano Martínez, Marcial

    2005-01-01

    El conocimiento de los ciclos de vida, de las estrategias reproductivas y de los factores que influyen sobre el proceso reproductivo de cualquier especie, son fundamentales para desarrollar programas de manejo sustentable de los recursos. En este estudio se analizó el proceso reproductivo de la almeja mano de león Nodipecten subnodosus en la laguna Ojo de Liebre, B.C.S., México, y su relación con el ciclo de almacenamiento y utilización de energía, así como la influencia de los factores ambie...

  6. Abundancia y distribución de juveniles de Farfantepenaeus aztecus (Ives 1891), F. duorarum (Burkenroad 1939) y Litopenaeus setiferus (Linnaeus 1767) en la Laguna Madre, Tamaulipas, México

    OpenAIRE

    Alberto Ocaña-Luna; Gabriela Hernández-Batún; Marina Sánchez-Ramírez

    2008-01-01

    Se analizó la distribución y abundancia de los juveniles de camarones peneidos en Laguna Madre, en base a las recolectas realizadas en los meses de octubre (1997) y enero, mayo, julio (1998), con una red cónica de 50 cm de diámetro y 505 de apertura de malla, con un flujómetro adaptado a la misma. Además se tomaron datos de salinidad y temperatura superficial. Se realizó un análisis de varianza (ANOVA) y una prueba de rangos múltiples (SNK) para comparar las tallas entre las especies. La espe...

  7. Ocorrência e distribuição de Cetengraulis edentulus (Cuvier (Teleostei, Engraulidae na Laguna de Itaipu, Niterói, Rio de Janeiro, Brasil Ocurrence and distribution of Cetengraulis edentulus (Cuvier (Teleostei, Engraulidae in the Itaipu lagoon, Niterói, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Doti Gay

    2000-06-01

    Full Text Available Cetengraulis edentulus (Cuvier, 1828 was collected in Laguna de Itaipu, Niterói, Rio de Janeiro, between february 1990 and january 1992. The analisys of spacial-seasonal occurence and biomass of C. edentulus (n=2843 showed the predominance of these species in cold time (april to sepetember in muddy sediment, with little depth and turbid water. This species was frequent in Laguna de Itaipu during the two years study, being more abundant in cold time. The biomass of C. edentulus was high in cold time too.

  8. Capital Social Organizacional Base de la Sustentabilidad Organizacional para el Desarrollo Ambiental y Económico: El Caso de las Micro y Pequeñas Empresas en la Explotación del Tule (Typha spp.) de la Laguna de Zapotláne

    OpenAIRE

    José G. Vargas-Hernández

    2010-01-01

    En este trabajo se analiza la sustentabilidad de las organizaciones que realizan actividades de explotación del tule Thypha spp. en la Laguna de Zapotlán y su impacto en el desarrollo socioeconómico y ambiental de los municipios de Gómez Farías y Zapotlán el Grande. La hipótesis inicial de trabajo se delimita con la consideración de que el escaso capital social de las organizaciones que realizan la explotación del tule de la Laguna de Zapotlán, limita la sustentabilidad del desarrollo, a pesa...

  9. Evaluación del estado trófico de la Laguna de Ayarza utilizando el modelo de simulacion WASP

    Directory of Open Access Journals (Sweden)

    Andrea Eunice Rodas

    2017-03-01

    Full Text Available Los modelos de simulación de calidad de agua, son herramientas ambientales que permiten interpretar y predecir la respuesta de un cuerpo de agua a las cargas contaminantes externas. El programa de simulación de calidad de agua (WASP versión 7.41 se utilizó para simular y evaluar la relación entre los nutrientes externos y la calidad de agua, en la Laguna de Ayarza, Santa Rosa, Guatemala. El modelo toma en cuenta dos ciclos de nutrientes (N y P, por medio de variables de calidad de agua: temperatura, nitrato (NO 3 , amonio (NH 4 , nitrógeno total (TN,fosfato (PO 4 , fósforo total (TP, y oxígeno disuelto (OD. El modelo se construyó tomando en cuenta la morfología del lago y las condiciones climáticas. El lago se dividió en siete segmentos, tomando en cuenta los flujos y los parámetros fisicoquímicos para cada uno. Se determinó el coeficiente de dispersión del lago y se calibró utilizando los datos de octubre 2010 a febrero 2011. El post-procesamiento se realizó por medio del software GNUPLOT. Los resultados de la modelación muestran que los valores de fósforo en todo el lago, presentan niveles de eutrofización, los valores de nitrógeno presentan niveles oligotróficos e indican que el lago soporta carga contaminanterelativamente alta.

  10. Evaluación del desempeño de la planta de tratamiento de aguas residuales urbanas de ILHA Solteira (SP por lagunas facultativas primarias

    Directory of Open Access Journals (Sweden)

    Iván Andrés Sánchez Ortiz

    2012-01-01

    Full Text Available El objetivo principal de esta investigación fue evaluar el desempeño de la Planta de Tratamiento de Aguas Residuales de Ilha Solteira-SP durante las diferentes épocas climáticas del año. Se realizó un levantamiento batimétrico de las lagunas facultativas primarias, un monitoreo de 24 horas y el seguimiento de su desempeño en 3 etapas de colecta de 3 meses de duración cada una. La planta tuvo cerca del 40% de su volumen efectivo ocupado por lodos; el efluente final registró una eficiencia media de remoción de la DBO de 80,2%; únicamente 3 muestras reportaron valores de NMP de Coliformes Fecales menores al tope de 1000/100mL definidos por la legislación; en la tercera etapa, los valores de sólidos sedimentables superaron el límite permisible de 1,0 mL/L. La mayor parte del tiempo y pese a las variaciones climáticas, la planta cumplió con la normatividad ambiental brasilera en términos de remoción de DBO y sólidos sedimentables, pero transgredió la norma en cuanto a NMP de Coliformes Fecales, evidenciando la necesidad de implementar un sistema de pos tratamiento que reduzca los eventuales impactos ambientales producidos por los efluentes y los riesgos a la salud pública en la zona de descarga y aguas abajo del vertimiento.

  11. Vulnerabilidad al incremento del nivel del mar: estrategias de adaptación en el área Cabo Codera-Laguna de Tacarigua, estado Miranda, Venezuela

    Directory of Open Access Journals (Sweden)

    María de Lourdes Olivo-Garrido

    2012-01-01

    Full Text Available Las investigaciones científicas están corroborando que estamos enfrentándonos a impactos sociales, ambientales y económicos, debido al incremento de temperatura del aire originado por el cambio climático antropogénico. El objetivo de este estudio es evaluar la vulnerabilidad socio-ambiental al incremento potencial del nivel del mar, enfatizando los impactos físicos, específi camente la pérdida de superfi cie terrestre que puede ocurrir en la zona comprendida desde cabo Codera hasta el extremo más oriental de la laguna de Tacarigua, estado Miranda. Se aplicó la Metodología común: siete pasos para evaluar la vulnerabilidad (IPCC, 1992. Se presentan los resultados obtenidos en el quinto paso metodológico, referido a la “formulación de estrategias de respuestas y evaluación de costos”. Se evaluaron los costos preliminares de algunas respuestas de adaptación al incremento del nivel del mar en 0,5 m. con la fi nalidad de explorar las posibles acciones a seguir para enfrentar la erosión y la inundación potencial: levantamiento de la infraestructura costera existente (12.839,80x106Bs. y mantenimiento de playas (53,2x10 6Bs.. Se concluye que los costos de protección estimados para las opciones evaluadas son muy significativos, de manera que la estrategia más viable es proceder a implantar un efectivo Manejo Integrado de Áreas Costeras.

  12. Movimientos prehistóricos y recientes en la intraplaca argentina a la latitud 33º s, Falla Las Lagunas, Sampacho, Córdoba

    Directory of Open Access Journals (Sweden)

    Guillermo Luis Sagripanti

    2011-12-01

    Full Text Available En la intraplaca argentina a la latitud 33º S, región sur de la provincia de Córdoba se ubica la falla Las Lagunas. Esta estructura con probada actividad cuaternaria posee antecedentes de fuertes paleoterremotos, de terremotos históricos y sismicidad asociada frecuente. La aplicación de métodos paleosismológicos y geodésicos han permitido cuantificar los movimientos prehistóricos y recientes de la falla. Los estudios paleosismológicos realizados mediante la excavación de trincheras perpendiculares a la falla, han permitido relevar deformaciones cosísmicas correspondientes a cuatro paleoterremotos ocurridos en el Holoceno superior. La información relevada permitió estimar el desplazamiento vertical de la falla de 0,20 mm/año y el horizontal de 0,16 mm/año. En la sección Chañaritos de esta falla se emplazó una red geodésica con el fin de detectar y medir movimientos horizontales y verticales lentos e imperceptibles. La red está formada por seis estaciones distribuidas en el bloque hundido y elevado de la falla. Las mediciones de precisión fueron realizadas con una estación total electrónica. Se realizaron cuatro mediciones entre los años 2003 y 2010, cuyos datos han permitido interpretar una modificación en el sentido del movimiento de rumbo y un desplazamiento cosísmico de 37 mm, que se adjudica a un evento natural único como el terremoto de M 8,8 de Concepción, Chile de 2010.

  13. Magma injection into a long-lived reservoir to explain geodetically measured uplift: Application to the 2007-2014 unrest episode at Laguna del Maule volcanic field, Chile

    Science.gov (United States)

    Le Mével, Hélène; Gregg, Patricia M.; Feigl, Kurt L.

    2016-08-01

    Moving beyond the widely used kinematic models for the deformation sources, we present a new dynamic model to describe the process of injecting magma into an existing magma reservoir. To validate this model, we derive an analytical solution and compare its results to those calculated using the Finite Element Method. A Newtonian fluid characterized by its viscosity, density, and overpressure (relative to the lithostatic value) flows through a vertical conduit, intruding into a reservoir embedded in an elastic domain, leading to an increase in reservoir pressure and time-dependent surface deformation. We apply our injection model to Interferometric Synthetic Aperture Radar (InSAR) data from the ongoing unrest episode at Laguna del Maule (Chile) volcanic field that started in 2007. Using a grid search optimization, we minimize the misfit to the InSAR displacement data and vary the three parameters governing the analytical solution: the characteristic timescale τP for magma propagation, the maximum injection pressure, and the inflection time when the acceleration switches from positive to negative. For a spheroid with semimajor axis a = 6200 m, semiminor axis c = 100 m, located at a depth of 4.5 km in a purely elastic half-space, the best fit to the InSAR displacement data occurs for τP=9.5 years and an injection pressure rising up to 11.5 MPa for 2 years. The volume flow rate increased to 1.2 m3/s for 2 years and then decreased to 0.7 m3/s in 2014. In 7.3 years, at least 187 × 106 m3 of magma was injected.

  14. Vulnerabilidad al incremento del nivel del mar: pérdida de tierra en el área Cabo Codera-Laguna de Tacarigua, estado Miranda, Venezuela

    Directory of Open Access Journals (Sweden)

    María de Lourdes Olivo

    2011-01-01

    Full Text Available Investigaciones recientes han demostrado que ciertas actividades productivas del ser humano, están incidiendo en el aumento de las concentraciones de los gases de efecto invernadero en la atmósfera, con una tendencia ascendente de la temperatura promedio superficial del aire desde finales del siglo XIX. El objetivo de este estudio es evaluar la vulnerabilidad socioambiental al incremento potencial del nivel del mar, enfatizando los impactos físicos, específicamente la pérdida de superficie terrestre que puede ocurrir en la zona comprendida desde cabo Codera hasta la laguna de Tacarigua, estado Miranda, mediante la aplicación de la Metodología común: siete pasos para evaluar la vulnerabilidad (IPCC, 1992. Se presentan los resultados obtenidos en el cuarto paso metodológico, referido a la "evaluación de los cambios físicos". Se concluye que las posibles pérdidas por inundación (15,43 km2 serían más relevantes que las generadas por erosión (5 km2, adicionalmente se estimó una regresión de la línea de costa de aproximadamente 23 ± 5,44 m en 100 años. Los efectos del ascenso del nivel del mar son un acelerador de la problemática ambiental que existe en el área de estudio, se recomienda implantar un manejo integrado de costas para lograr su desarrollo sostenible

  15. Vulnerabilidad al incremento del nivel del mar: usos de la tierra y valor capital en el área Cabo Codera-Laguna de Tacarigua, estado Miranda, Venezuela

    Directory of Open Access Journals (Sweden)

    María de Lourdes Olivo

    2010-01-01

    Full Text Available A lo largo de estos últimos años se ha observado que el ser humano está transformando rápidamente el planeta, causando su degradación y conduciendo a efectos globales que modifican el ambiente terrestre, acuático y la atmósfera. El objetivo de la investigación es el de evaluar la vulnerabilidad socio-ambiental al incremento potencial del nivel del mar por al cambio climático, enfatizando los impactos físicos, específicamente la pérdida de tierra desde cabo Codera hasta el extremo más oriental de la laguna de Tacarigua, en el estado Miranda. Se aplicó la Metodología común: siete pasos para evaluar la vulnerabilidad (IPCC, 1992. En este artículo se presentan los resultados obtenidos en el tercer paso metodológico, referido a la ¿Identificación de los factores de desarrollo¿. Se concluye que el uso turístico-recreacional ocupa la mayor superficie (aproximadamente 37,60%, seguido del residencial (27,30% en el área de estudio. De no haber una respuesta efectiva ante el incremento del nivel del mar, estaría en situación de riesgo un valor capital significativo en infraestructura turística (132,90x106 Bs., urbana (96,40x106 Bs. y hasta la vialidad (13x106 Bs., con serias implicaciones sociales, económicas y ecológicas. Es de resaltar que las cifras son referenciales y no conllevan un análisis económico definitivo.

  16. DINÁMICA DE LA PRODUCCIÓN PRIMARIA FITOPLANCTÓNICA EN UN SISTEMA EUTRÓFICO TROPICAL: LAGUNA DEL PARQUE NORTE, MEDELLÍN, COLOMBIA

    Directory of Open Access Journals (Sweden)

    RAMÍREZ-R JOHN J.

    2002-12-01

    Full Text Available Entre marzo de 1999 y enero de 2000 se llevaron a cabo muestreos quincenales enuna sola estación, la cual se situó en el sitio más profundo de la laguna del ParqueNorte. Todas las muestras de agua y de fitoplancton fueron recogidas a una solaprofundidad correspondiente al límite de la zona fótica. En este ecosistema parte dela biomasa no se respira, lo que implica que hay una producción neta disponiblepara los demás componentes de la cadena trófica y para ser reciclada dentro dellago; por ello, el lago funciona como una trampa de nutrientes con metabolismo detipo autotrófico, una reducida contribución alóctona, un nivel de entropía bajo, ylimitado más por el fósforo disponible que por la luz. Durante el tiempo de muestreola comunidad permaneció en el mismo estado sucesional, como es mostrado por ladominancia de B. braunii. El valor medio de la Productividad Primaria Bruta fue altocomparado con el de otros lagos colombianos. Las bajas concentraciones de CO2libre y los valores altos, alcalinos y poco variables de pH ocasionados por la demandade la fracción libre del carbono inorgánico disuelto corroboran esta condición. Laproductividad se asoció significativamente con la conductividad y con la razónclorofila a/fósforo total.

  17. Los carábidos (Coleoptera: Carabidae asociados a los remanentes de bosque nativo en la Reserva Natural Municipal Laguna de los Padres, Buenos Aires

    Directory of Open Access Journals (Sweden)

    Darío P. PORRINI

    2014-01-01

    Full Text Available Frente a la amenaza que ha provocado la expansión de la exótica zarzamora (Rubus ulmifolius (Schott en la Reserva Natural Municipal Laguna de los Padres (RNMLP, surgió la necesidad de estudiar los ensambles de carábidos asociados a los remanentes de bosque nativo de “curro” (Colletia paradoxa ((Spreng. Escal., tala (Celtis ehrenbergiana (Klotzsch Liebm. y sauce (Salix humboldtiana (Willd que aún persisten. Se encontró que la riqueza específica es mayor en el bosque de S. humboldtiana (DE, seguida por el bosque de C. paradoxa (BC y luego por los bosques de C. ehrenbergiana con distinto uso antrópico (Talar de uso recreativo (TR y Talar antropizado (TA. BC y DE localizados dentro de la zona intangible y de conservación, tomados en conjunto, aportaron más del 85% (53 especies de la riqueza específica total relevada, mientras que TR y TA ubicados fuera de estas zonas aportaron un 56% (35 especies. Los ensambles de carábidos fueron diferentes a lo largo del año y entre sí para los distintos bosques. La especie más abundante fue Argutoridius bonariensis (Dejean y dominó los ensambles de TA y TR durante las cuatro estaciones. En DE y BC se destacaron especies propias y un endemismo para el DE. Los predadores constituyeron el gremio trófico más abundante para todos los sitios. Se discutió para cada bosque su estado de conservación y los posibles factores naturales o artificiales que condicionan la diversidad de carábidos encontrada.

  18. Mineralogia y geoquimica de los sedimentos de algunas lagunas del N de la provincia de Málaga (S de España

    Directory of Open Access Journals (Sweden)

    Benavente, J.

    2001-08-01

    Full Text Available Similar compositional and genetic characteristics for the recently deposited sediments in some lakes and ponds of the north of the Málaga province have been observed. Nevertheless, it seems to exist some differences in their mineralogical and geochemical evolution as well as in the degree of alteration of the original sediment. The mineral alterations produced in these confined lacustrine basins, with pH higher than 8, are controlled by ionic exchange between water and sediment. According to the mineral alteration degree three stadiums of mineral evolution have been detected. In addition the mineralogical and geochemical evolution and the hydrochemical characteristic of the aqueous environment are related. The study has shown that some neoformation processes of Mgrich minerals also occur.Se han observado características composicionales y genéticas similares en los sedimentos más recientes de algunas lagunas del norte de la provincia de Málaga, si bien parecen existir diferencias en su evolución mineralógica y geoquímica y en el grado de alteración del sedimento original. Las alteraciones minerales producidas en estos medios lacustres confinados, con pH superior a 8, están controladas por los intercambios iónicos entre el agua y el sedimento. Según el grado de alteración mineral detectado se han observado tres estadios de evolución mineral para estos sedimentos. Igualmente, se observa una relación entre la evolución mineralógica y geoquímica y las características hidroquímicas del agua existente en el medio. El estudio ha mostrado indicios de neoformación de minerales ricos en Mg+2.

  19. Movimientos prehistóricos y recientes en la intraplaca argentina a la latitud 33º s, Falla Las Lagunas, Sampacho, Córdoba Prehistoric and recent movements in the Argentine intraplate, at the latitude 33º S, Las Lagunas fault, Sampacho, Córdoba

    Directory of Open Access Journals (Sweden)

    Guillermo Luis Sagripanti

    2011-12-01

    Full Text Available En la intraplaca argentina a la latitud 33º S, región sur de la provincia de Córdoba se ubica la falla Las Lagunas. Esta estructura con probada actividad cuaternaria posee antecedentes de fuertes paleoterremotos, de terremotos históricos y sismicidad asociada frecuente. La aplicación de métodos paleosismológicos y geodésicos han permitido cuantificar los movimientos prehistóricos y recientes de la falla. Los estudios paleosismológicos realizados mediante la excavación de trincheras perpendiculares a la falla, han permitido relevar deformaciones cosísmicas correspondientes a cuatro paleoterremotos ocurridos en el Holoceno superior. La información relevada permitió estimar el desplazamiento vertical de la falla de 0,20 mm/año y el horizontal de 0,16 mm/año. En la sección Chañaritos de esta falla se emplazó una red geodésica con el fin de detectar y medir movimientos horizontales y verticales lentos e imperceptibles. La red está formada por seis estaciones distribuidas en el bloque hundido y elevado de la falla. Las mediciones de precisión fueron realizadas con una estación total electrónica. Se realizaron cuatro mediciones entre los años 2003 y 2010, cuyos datos han permitido interpretar una modificación en el sentido del movimiento de rumbo y un desplazamiento cosísmico de 37 mm, que se adjudica a un evento natural único como el terremoto de M 8,8 de Concepción, Chile de 2010.Las Lagunas fault is located in the argentine intraplate at latitude 33ºS, in the southern region of the Cordoba province. This structure with proved Quaternary activity has records of strong paleoearthquakes, historical earthquakes, and associated frequent seismicity. Paleoseismic and geodesic methods have permitted to quantify the prehistoric and recent movements of the fault. Paleoseismic studies done in trenches across the fault, have permitted the recognition of coseismic deformation corresponding to four paleoearthquakes occurred in the

  20. The Pali Aike Windstreak Field, Southern Patagonia, Argentina

    Science.gov (United States)

    Rodriguez, J. A. P.; Zimbelman, J. R.; Kargel, J. S.; Tanaka, K. L.; Yamamoto, A.; Sasaki, S.

    2008-03-01

    Windstreaks are amongst the most common aeolian landforms on Mars, yet they are extremely rare on Earth. We have identified and carried out field based observations of an outstanding zone of windstreaks in southern Patagonia Argentina.

  1. Estudios de interés tafonómico en los restos óseos humanos de Laguna Tres Reyes 1 (Partido de Adolfo Gonzales Chaves, provincia de Buenos Aires Taphonomic studies of human bones from Laguna Tres Reyes 1 (Gonzales Chaves District, Buenos Aires province, Argentina

    Directory of Open Access Journals (Sweden)

    Mariela Edith González

    2007-12-01

    Full Text Available En este trabajo se presentan los resultados del análisis de los efectos tafonómicos del registro bioarqueológico del sitio Laguna Tres Reyes 1 (Partido de Adolfo Gonzales Chaves, realizado en el marco de la tesis de licenciatura. La metodología consistió en el examen macroscópico de la superficie cortical de cada elemento esqueletal sobre el conjunto de entierros primarios. Las variables analizadas fueron: marcas de raíces, depositación química (carbonato de calcio y manchas de manganeso, pérdida ósea, fracturas, actividad de roedores, acción de carnívoros, marcas de excavación y limpieza, meteorización e integridad. Los resultados indican la interacción de una serie de agentes y procesos tafonómicos sobre los huesos humanos que condujeron a una historia tafonómica compleja y de baja intensidad, permitiendo una muy buena preservación del tejido óseo. Los roedores han perturbado este registro fundamentalmente en el aspecto distribucional dejando escasas marcas de su accionar sobre los elementos óseos. Por otro lado, existen evidencias de la acción de pequeños carnívoros sobre algunos esqueletos que sugieren que estos animales habrían accedido a ellos deslizándose por los túneles y cuevas excavados por los roedores.This paper presents the results of taphonomic research carried out on the bioarchaeological record of the Laguna Tres Reyes 1 site (Buenos Aires Province, Argentina. The variables analyzed were root etching, chemical deposition (calcium carbonate coating and manganese staining, bone destruction, fractures, rodent and carnivore activities, excavation and cleaning marks, weathering, and bone integrity. Based on a macroscopic examination of the surface of the human bones found at the site, this study shows that the skeletons were affected by the activity of small rodents, which left scarce traces on the bones. It is also suggested that small-sized carnivores were able to reach the burials through tunnels

  2. Abundancia y distribución de juveniles de Farfantepenaeus aztecus (Ives 1891, F. duorarum (Burkenroad 1939 y Litopenaeus setiferus (Linnaeus 1767 en la Laguna Madre, Tamaulipas, México Juveniles abundance and distribution of Farfantepenaeus aztecus (Ives 1891, F. duorarum (Burkenroad 1939 and Litopenaeus setiferus (Linnaeus 1767 in Laguna Madre, Tamaulipas, Mexico

    Directory of Open Access Journals (Sweden)

    Alberto Ocaña-Luna

    2008-12-01

    Full Text Available Se analizó la distribución y abundancia de los juveniles de camarones peneidos en Laguna Madre, en base a las recolectas realizadas en los meses de octubre (1997 y enero, mayo, julio (1998, con una red cónica de 50 cm de diámetro y 505 de apertura de malla, con un flujómetro adaptado a la misma. Además se tomaron datos de salinidad y temperatura superficial. Se realizó un análisis de varianza (ANOVA y una prueba de rangos múltiples (SNK para comparar las tallas entre las especies. La especie más abundante fue Farfantepenaeus aztecus con el 84.5% de la abundancia total, seguida por Litopenaeus setiferus con el 10.6% y Farfantepenaeus duorarum con el 3.4%, en el invierno la abundancia de F. aztecus y L. setiferus fue mayor. Se observaron diferencias significativas entre las tallas de juveniles de F. aztecus (11.7 mm y L. setiferus (11.8 mm con respecto a la talla de F. duorarum (11.0 mm (F = 7.81, p = 0.05; SNK = 0.71, p = 0.05; SNK = -0.83, p = 0.05.The Penaeid shrimp planktonic juvenile distribution and abundance from Laguna Madre were analyzed, based in samples collected in the months of October 1997, January, May and July 1998 with a conical net of 50 cm diameter and 505 mesh size, with an adapted flowmeter; moreover water salinity and superficial temperture data were recorded. The size among species was compared with a variance analysis (ANOVA and a multiple ranks test (SNK. Farfantepenaeus aztecus was the most abundant species with 84.5% of the total abundance, following by L. setiferus with 10.6% and F. duorarum with 3.4%. The abundance of F. aztecus and L. setiferus was greatest during the winter. Significant differences were observed between the sizes of juveniles of F. aztecus (11.7 mm and L. setiferus (11.8 mm with respect to the size of F. duorarum (11.0 mm (F = 7.81, p = 0.05; SNK = 0.71, p = 0.05; SNK = -0.83, p = 0.05.

  3. Paleosismicidad y estimación del intervalo derecurrencia de fuertes terremotos asociados a fallas de intraplaca a la latitud33ºs, falla Las Lagunas, Sampacho, Córdoba Paleoseismicity and estimation of therecurrence interval during strong earthquakes associated with intraplate faultsat the 33ºS latitude, Las Lagunas fault, Sampacho, Córdoba

    Directory of Open Access Journals (Sweden)

    GuillermoLuis Sagripanti

    2009-11-01

    Full Text Available Las morfologías y deformaciones de sedimentoscuaternarios sumadas a la sismicidad superficial manifiesta en un sector deintraplaca de Argentina a la latitud 33ºS, región sur de la provincia deCórdoba, ponen en evidencia que la actividad tectónica del Mioceno-Pleistocenotiene continuidad en el Holoceno. Seguramente esta actividad ha tenido asociadala ocurrencia de fuertes terremotos, desconociéndose de estos últimos sunúmero, magnitud e intervalo de recurrencia. El objetivo del presente trabajoes, por medio de investigaciones paleosismológicas y mediante la apertura detrincheras, relevar evidencias de deformaciones cosísmicas para hacer unacontribución a la reconstrucción del registro de la sismicidad prehistórica yestimar el intervalo de recurrencia de fuertes terremotos, para la región. Conla información obtenida de la descripción e interpretación de los perfileslitológicos y estructuras mesoscópicas de dos trincheras se elaboró un modelode retrodeformación del fallamiento para la falla Las Lagunas, determinando laocurrencia de múltiples paleoterremotos en los últimos 3.700 años y estimandouna recurrencia para este sector de intraplaca entre 900 y 1.200años.Morphologies and deformations of Quaternary sediments, added to theoccurrence of shallow seismicity in a sector of the Argentine intraplate atlatitude 33ºS, in the southern region of Córdoba province, evidence that theMiocene-Pleistocene tectonic activity continued into the Holocene. Thisactivity has been certainly associated with strong earthquake occurrences,whose number, magnitude and recurrence interval remained unknown. The objectiveof the present work is to reconstruct the prehistoric seismicity and toestimate the recurrence interval of strong earthquakes for the region throughpaleoseismic investigations based on the study of coseismic deformations intrenches. Data obtained from the description and interpretation of lithologicprofiles and mesoscopic

  4. SIMPRO, a practical tool for training the staff of Laguna Verde nuclear power plant; El SIMPRO, una herramienta practica para la capacitacion y entrenamiento del personal de la CNLV

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Valdez, Guillermo Omar; Gomez Camargo, Octavio; Castelo Cuevas, Luis; Vazquez Bustos, Jesus [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2012-06-22

    Laguna Verde Nuclear Power Plant (LVNPP) has implemented a real physical model, which represents several parts of a simplified version of its process. This development has proved to be very useful to improve the compliance with training programs and staff training maintenance in the different disciplines of engineering. Such programs are required by regulations and standards applicable for Nuclear Power Plants (NPP), so that the personnel working in these facilities can be able to respond on time to any contingency that might arise. This paper outlines the creation of the real physical model, how it is integrated and some of the practices that can be performed on this model. [Spanish] La Central Nucleoelectrica de Laguna Verde ha implementado un modelo fisico real que representa varias partes de una version simplificada de su proceso. Este desarrollo ha demostrado ser muy util para mejorar el cumplimiento de programas de adiestramiento, incluidos los del personal de mantenimiento, en diferentes disciplinas de ingenieria. Dichos programas son requeridos por las regulaciones y normas aplicables a las centrales nucleoelectricas, de manera que el personal que trabaja en estas instalaciones pueda ser capaz de responder oportunamente a cualquier contingencia que pudiera surgir. Este articulo describe la creacion del modelo fisico real, como se integra y algunas de las practicas que pueden llevarse a cabo con el.

  5. Simulations of the design basis accident at conditions of power increase and the o transient of MSIV at overpressure conditions of the Laguna Verde Power Station; Simulaciones del accidente base de diseno a condiciones de aumento de potencia y del transitorio de cierre de MSIV a condiciones de sobrepresion de la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Araiza M, E.; Nunez C, A. [Comision Nacional de Seguridad Nuclear y Salvaguardias, 03000 Mexico D.F. (Mexico)

    2001-07-01

    This document presents the analysis of the simulation of the loss of coolant accident at uprate power conditions, that is 2027 MWt (105% of the current rated power of 1931MWt). This power was reached allowing an increase in the turbine steam flow rate without changing the steam dome pressure value at its rated conditions (1020 psiaJ. There are also presented the results of the simulation of the main steam isolation va/ve transient at overpressure conditions 1065 psia and 1067 MWt), for Laguna Verde Nuclear Power Station. Both simulations were performed with the best estimate computer code TRA C BF1. The results obtained in the loss of coolant accident show that the emergency core coolant systems can recover the water level in the core before fuel temperature increases excessively, and that the peak pressure reached in the drywell is always below its design pressure. Therefore it is concluded that the integrity of the containment is not challenged during a loss of coolant accident at uprate power conditions.The analysis of the main steam isolation valve transients at overpressure conditions, and the analysis of the particular cases of the failure of one to six safety relief valves to open, show that the vessel peak pressures are below the design pressure and have no significant effect on vessel integrity. (Author)

  6. Innovation, creative ideas to attend the challenges of the Central Laguna Verde for the period 2011-2015 due to new 100% of power; Innovacion, ideas creativas para atender los retos y desafios del periodo de la Central Laguna Verde en 2011-2015 por el nuevo 100% de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Rivera C, A., E-mail: arr99999@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km 42.5, Veracruz (Mexico)

    2011-11-15

    For the nuclear power plant of Laguna Verde (CLV) is an opportunity to present to the nuclear community in Mexico the improvement areas and challenges for the period 2011-2015, now that has been concluded the phase of starting tests of the CLV modernization, with an increment of power of 20% that represents a new generation of electrical power of 815 M We per hour in the 2 Units, with these new challenges the strategic planning 2011 at 2015 take relevance to give guide to the innovation, with new ideas of improvement to the processes, human resources and leadership, with the purpose of maintaining reliable all the equipment s and process systems by means of the use of strengths, opportunities, vulnerabilities and threats analysis, in order to make strategies that aid to generate competitive advantages for the production of electric power in Mexico, using privileged information that contain the database of the improvement systems, like are the programs of corrective action, of human acting, of external operational experience, of auto-evaluation and of benchmarking that is the referential comparison with other similar power stations. At present, in the general management of operation exist the training by coaching to grow in the formation of the half commands and line supervisors, reinforcing the wanted behaviors, the abilities of the technicians, and the orientation in deficient performances in the search of the operational excellence. (Author)

  7. Long-Term Performance of the Laguna de Barlovento Reservoir Water-Proofing using a PVC-P Geo membrane; Impermeabilizacion de la balsa de la Laguna de Barlovento con geomembrana de PVC-P: evolucion a lo largo del tiempo

    Energy Technology Data Exchange (ETDEWEB)

    Blanco Fernandez, M.; Leiro Lopez, A.; Soriano Carrillo, J.; Crespo Mucientes, M.; Zornberg, J.; Aguilar Gonzalez, E.; Rico Arnaiz, G.; Pargada Iglesias, L.

    2014-02-01

    The Laguna de Barlovento reservoir was one of the most important European hydraulic projects at the time of its construction because of its high capacity and challenging location. At the time, the designers decided to waterproof this reservoirs with a geo membrane of plasticized polyvinyl chloride (PVC-P). This paper documents the initial characteristics of the geo membrane and its performance since its installation until 2010. The material characterization includes a comprehensive testing program, the results of which are presented. They include quantification of the geo membrane thickness, amount and nature of plasticizers, tensile properties, fold ability under low temperatures, dynamic impact resistance, puncture resistance, welding strength (both in the manufacturing facility and in the field), as well as the use of techniques involving optical and scanning electron microscopy. In addition, advanced analytical techniques, such as Fourier Transform Infrared Spectroscopy (FTIR), Gas Chromatography (GC) and Mass spectrometry (MS), were used in order to identify the plasticizers used in the geo membrane formulation. Fold ability tests were found to provide early indication of degradation. Results from reflection optical and electron scanning microscopy showed that, after 19 nineteen years of installation, the geo membrane remains in good conditions, particularly on the non-exposed side. (Author)

  8. Changes in reactivity and in the margins to thermal limits by the inclusion of control rods of advanced type in the Laguna Verde Power plant; Cambios en la reactividad y en los margenes a limites termicos por la inclusion de barras de control de tipo avanzado en la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, J.L.; Perusquia, R.; Montes, J.L.; Ortiz, J.J.; Ramirez, J.R. [ININ, Depto. de Sistemas Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail: jlhm@nuclear.inin.mx

    2004-07-01

    The obtained results are presented when simulating with CM-PRESTO code the cycle 10 of the unit 1 of the Laguna Verde Central, using two advanced types of control bars, besides the originally loaded ones. The two advanced types, to those that are denominated 1AV and 2AV in this work, are of different design, however both have in some place of the bar, a section with hafnium like neutron absorber material. They thought about three different scenarios, in the first one, used as reference, is simulated the cycle 10 using the original control bars, while in the other two cases the advanced types are used. The values of the reactivity were compared and of some margins to the thermal limits obtained when using the bars of advanced type, with those obtained in the case in that alone they are considered those original bars. It was found that in condition of power both advanced types present bigger absorber power of neutrons that the original bars, being quantified in average this bigger power in 0.22 pcm/notch for the type 1AV and in 0.51 pcm/notch for the type 2AV. The affectation of the margins to the observed thermal limits is minimum. (Author)

  9. Scenarios simulation of severe accident type small loss of coolant (Loca), with the code MELCOR version 2.1 for the nuclear power plant of Laguna Verde; Simulacion de escenarios de accidente severo tipo perdida de refrigerante (Loca) pequeno, con el codigo MELCOR version 2.1 para la central nucleo-electrica de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas V, J.; Mugica R, C. A.; Godinez S, V., E-mail: Jaime.cardenas@cnsns.gob.mx [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Jose Ma. Barragan No. 779, Col. Narvarte, 03020 Mexico D. F. (Mexico)

    2013-10-15

    In this work was carried out the analysis of two scenarios of the accident type with loss of coolant in a recirculation loop for a break with smaller ares to 0.1 ft{sup 2} (4.6 cm{sup 2}), which is classified according to their size like small Loca. The first simulated scenario was a small Loca without action of the emergency coolant injection systems, and the second was a small Loca with only the available system LPCS. This design base accident was taken into account for its relevance with regard to the damage to the core and the hydrogen generation. Was also observed and analyzed the response of the action of the ECCS that depend of the loss of coolant reason and this in turn depends of the size and type of the pipe break. The specified scenarios were simulated by means of the use of MELCOR model for the nuclear power plant of Laguna Verde that has the Comision Nacional de Seguridad Nuclear y Salvaguardias. (Author)

  10. Range of the radiation monitor for the rigid vent of primary containment during normal and emergency operation for a BWR-5 in Laguna Verde; Rango del monitor de radiacion para el venteo rigido de la contencion primaria durante operacion normal y emergencia para un reactor BWR-5 en Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Tijerina S, F.; Pozos S, A. M.; Cabrera U, S.; Mata A, J. A.; Sandoval V, S.; Ovando C, R.; Vargas A, A.; Gallardo R, I.; Cruz G, M.; Amador C, C., E-mail: francisco.tijerina@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Subgerencia de Ingenieria, Km 44.5 Carretera Cardel-Nautla, 91476 Laguna Verde, Alto Lucero, Veracruz (Mexico)

    2014-10-15

    The earthquake followed by a tsunami, happened in March, 2011 in the coasts of oriental Japan, caused damages in the nuclear power plants 1 at 4 of Fukushima Daiichi leading to damage of the fuel in three of the reactors and to the radiation liberation to the exterior. As consequence of those events, the regulations requires that the power plants with Primary Containment type Mark I and II evaluate to have a system of rigid vent with a monitoring equipment of radiation effluents. The present work covers the rigid vent of diameter 12 of the Primary Containment, type Mark-II, of nuclear power plant of Laguna Verde in conditions of severe accident and normal operation, low regime of Extended Power Up rate (EPU - 2317 MWt), using the codes MAAP3B, MICROSHILED 5.05 and the Bardach Black Boxes methodology. As a result the measurement range of the radiation monitor that is required for monitoring the gassy liberation to the atmosphere was determined. The conclusion is that the superior limit of the range of the radiation meter during a Severe Accident is of 8.55 E + 05 R/h (8.55 E + 08 m R/h) and the superior limit in normal operation of 1.412 E-11 at 2.540 E-7 R/h (1.412 E-14 at 2.540 E-10 m R/h). (Author)

  11. Quality studies of the energy in the electric net of the gathering warehouse of reusable parts and contaminate oils of the nuclear power plant Laguna Verde; Estudios de calidad de la energia en la red electrica del almacen de acopio de partes reusables y aceites contaminados (CCAC) de la Central Nuclear Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Tijerina S, F.; Vargas A, A.; Cardenas J, J., E-mail: francisco.tijerina@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Subgerencia de Ingenieria, Carretera Cardel-Nautla Km 42.5, Veracruz (Mexico)

    2012-10-15

    In the industry exist the high costs by faults of electronic and electric equipment s, due to during the design process, installation, tests and operation of these equipment s, is not had appropriate detection equipment to carry out quality studies of the energy. These studies give an important support to know that occurs in an electric net, the cause of the anomalous behavior of the equipment s and this way to avoid the expensive faults carrying out necessary engineering adaptations in an electric net. The elements of the electricity that are determined are the tension, current and frequency that are inside acceptable operational parameters that facilitate the operation and constant operation of the equipment s, free of interruptions and failures. The application of the quality studies of the energy is growing little by little in Mexico for the problems solution in the equipment s. This field is also developing new techniques and technologies integrated in the equipment s for its monitoring detection and protection. The present work offers the results of the first Quality Study of the Energy in the nuclear power plant of Laguna Verde to solve the problem in the gathering warehouse of reusable parts and contaminate oils, in which the failure of the two radiation monitors of the gassy effluent of ventilation HVAC of the warehouse took place. (Author)

  12. Analysis of the evolution of reactivity of the event at 24/01/1995 of the BWR U-1 of Laguna Verde; Analisis de la evolucion de la reactividad del evento del 24/01/1995 del BWR U-1 de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz E, J.A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Blazquez M, J. [CIEMAT, 28040 Madrid (Spain)]. e-mail: jare@nuclear.inin.mx

    2003-07-01

    In this work it is looked for, to calculate the reactivity starting from the measure