37,430 research outputs found
Letter from Carl T. Hayden to C. H. Gensler, Havasupai Reservation
No full textLetter from Carl T. Hayden to C. H. Gensler, Havasupai Indian Reservation, regarding Hualapai and Cataract Canyons geography
Upper crustal structure of an active volcano from refraction/reflection tomography, Montserrat, Lesser Antilles
No full textTo better understand the volcanic phenomena acting on Montserrat, the SEA-CALIPSO seis-mic experiment (Seismic Experiment with Airgun-source – Caribbean Andesitic Lava Island Precision Seismo-geodetic Observatory) was conducted in 2007 December with the aim of imaging the upper crust and the magmatic system feeding the active Soufri ?ere Hills Volcano. The 3-D survey covered an area of about 50
× 40 km and involved the deployment of 247 land stations and ocean-bottom seismometers (OBSs). A subset of the data, recorded by four OBSs and four land stations on a southeast to northwest line, has been analysed, and traveltimes have been inverted to obtain a 2-D seismic velocity model through the island. Inverted phases include crustal and sediment P waves and wide-angle reflections. The resulting velocity model reveals the presence of a high velocity body (3.5–5.5 km s?1 ) beneath the island, with highest velocities beneath the Soufri ?ere and Centre Hills, cor responding primarily to the cores of these volcanic edifices, built of a pile of andesite lava domes and subsequent intrusions. In the off-shore region, velocities in the surficial sediment layer vary from 1.5 to 3.0 km s?1 , consistent with a mainly calcareous and volcaniclastic composition. A wide-angle reflector is observed at a depth of ?1200 m below the seabed, and appears to deepen beneath the island. The upper crust beneath this reflector has velocities of 4.0–6.0 km s?1 and is infer red to cor respond to plutonic and hypabyssal rocks and sedimentary material of the old arc. The high velocity region beneath the island, extends into the crust to a depth of at least 5 km, and is believed to be caused by an intrusive complex, possibly of intermediate composition. A low velocity zone, as would be expected in the presence of an active magma chamber, was not observed perhaps due to the limited resolution beneath ?5 km depth. Our results so far provide the first wide-angle seismic constraints on the upper crustal structure of the island to a depth of 10 km, and will help understanding the processes that drive volcanism at Montserrat and other island arc volcanoes
Letter from Charles H. Burke to Carl Hayden
No full textLetter from Charles H. Burke to Carl T. Hayden about mining on Diné (formerly Navajo) national land
Letter from John H. Page to Carl Hayden
No full textLetter from John H. Page to Carl T. Hayden regarding his company's rights to build a railway if they choose to
Mesophilic-hydrothermal-thermophilic (M-H-T) digestion of green corn straw
No full textMesophilic-hydrothermal (80-160 degrees C, 30 min)-thermophilic (M-H-T) digestion and control tests of mesophilic (M), thermophilic (T), hydrothermal-mesophilic (H-M), and mesophilic-thermophilic digestion (M-T) of green corn straw were conducted for a 20-day fermentation period. The results indicate that M-H-T is an efficient method to improve methane production. A maximum methane yield of 371.74 mL/g volatile solid was obtained by the M (3 days)-H (140 degrees C)-T (17 days) process, which was 20.44%, 16.55%, 31.44%, and 14.31% higher than the yields of the M, T, 140-M, and M-T processes. The enhanced methane production was attributed to (1) the improved hemicellulose degradation and lignin disorganization; (2) prevention of the degradation of soluble sugar, easily hydrolyzed hemicellulose and cellulose into furfural and methylfurfural; and (3) lack of formation of Maillard reaction products during initial hydrothermal treatment. (C) 2015 Elsevier Ltd. All rights reserved
Reconstructing the exhumation history of the Lesser Himalaya, Northern, India, from a multi-technique provenance study of the foreland basin Siwalik Group.
No full textThis research presents the first multitechnique provenance study of the Siwalik Group in the Himalayan foreland basin in India, using the Jawalamukhi section, magnetostratigraphically dated at 13–5 Ma. Combined with provenance data from a Dharamsala Formation sedimentary section (21–13 Ma) located close by, it forms the longest temporally continuous record of Himalayan erosion in the Indian foreland basin. Sandstone petrography and heavy mineral analysis, conglomerate clast composition, Ar‐Ar dating of detrital white micas, and Sm‐Nd analyses on siltstones, conglomerate matrix and conglomerate clasts was undertaken to determine (1) shifts in source region through time and (2) changes in detrital lag times related to exhumation rates in the hinterland, together interpreted in the light of thrusting events. We interpret the data to show a slow down in exhumation rate of the Higher Himalaya by 16–17 Ma, after which time the locus of thrusting propagated south of the Main Central Thrust, and erosion of the low grade Haimanta Formation to the south became significant. The nonmetamorphosed Inner Lesser Himalaya breached its Haimanta cover by 9 Ma with the metamorphosed Inner Lesser Himalaya (Lesser Himalayan Crystalline Series) exhuming to surface by 6 Ma. This event caused sufficient disruption to established drainage patterns that all Higher Himalayan material was diverted from this location at this time
Letter from Carl Hayden to Charles H. Akers
No full textLetter from Carl Hayden to C. H. Akers on the opposition to the Grand Canyon bill from A. A. Johns, J. W. Sullivan, Jesse Hoyce, T. E. Cureton, and Hugh Campbell. Hayden mentions his failure to contact the governor before the present special session, but expresses hope of the legislature passing a memorial on the subject
Measuring industry-science links through inventor-author relations: A profiling method
No full textIn this pilot study we examine the performance of text-based profiling in recovering a set of validated inventor-author links. In a first step we match patents and publications solely based on their similarity in content. Next, we compare inventor and author names on the highest ranked matches for the occurrence of name matches. Finally, we compare these candidate matches with the names listed in a validated set of inventor-author names. Our text-based profile methodology performs significantly better than a random matching of patents and publications, suggesting that text-based profiling is a valuable complementary tool to the name searches used in previous studies.innovation; industry-science links; text-based profiling;
Reproductive decisions in the lesser black-backed gull larus fuscus and their effects on reproductive success
No full textThe effect of several fundamental reproductive 'decisions' upon reproductive success were examined over a three year period at a large, inland gullery in the Pennines. Variations in reproductive parameters in relation to timing of breeding and reproductive success were compared among years. Determinants of the degree of hatching asynchrony were identified. Eggs from two years were taken for yolk lipid analysis, using gas chromatography. Variation in micronutrient content of eggs within clutches and between years was assessed in relation to egg size and yolk size, in order to examine resource allocation decisions of individuals. Timing of breeding of individuals was experimentally manipulated through the exchange of whole clutches of eggs between early and late laying birds, whilst controlling for variation in clutch size and egg-size, in order to assess whether the seasonal decrease in reproductive success was best explained by a decrease in food supply or differences in quality among parents. I experimentally manipulated the within-brood mass hierarchy of gulls, whilst controlling for variation in both chick quality and parental quality, in order to assess the effect of hatching asynchrony per se on chick growth and survival, and whether parents optimized the degree of hatching asynchrony with respect to the prevailing food supply. Brood size was experimentally reduced in order to assess the costs and benefits of the production of supernumary young. This was acheived by comparison of chick growth, feather development and chick survival of unmanipulated three-chick broods with broods where either the a-chick or the c- chick had been removed. I present a general discussion of the results within the context of life-history theory and a model for the evolution of hatching asynchrony in the lesser black-backed gul
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