Filters: Tags: Age (X)25 results (1.9s)
Studies conducted since the late 1970s have estimated the net energy value (NEV) of corn ethanol. However, variations in data and assumptions used among the studies have resulted in a wide range of estimates. This study identifies the factors causing this wide variation and develops a more consistent estimate. We conclude that the NEV of corn ethanol has been rising over time due to technological advances in ethanol conversion and increased efficiency in farm production. We show that corn ethanol is energy efficient as indicated by an energy output:input ratio of 1.34.
Summary A detailed local-scale monitoring network was used to assess CFC distribution in an unconfined sand aquifer in southwestern Ontario where the zone of 1–5-year-old groundwater was known with certainty because of prior use of a bromide tracer. Groundwater ⩽5 years old was confined to an aerobic zone at ⩽5 m depth and had CFC concentrations consistent with modern atmospheric mixing ratios at recharge temperatures of 7–11 °C, as was observed in the 3-m thick vadose zone at the site. At depths below 6 m, the groundwater became progressively more reducing, however, with a denitrifying horizon at 6–7 m depth, and a Mn and Fe reducing zone below 7 m depth. In the anaerobic zone, 3H/3He ratios indicated that groundwater-age...
Socio-economic data by county subdivision in Vermont, New Hampshire and Maine.Â Includes population density, median age, education levels, vacation homes, incomes, poverty, unemployment, employment in key sectors.
Surficial geology (geo7_2ag).
The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States (https://doi.org/10.5066/F7WH2N65) represents a seamless, spatial database of 48 State geologic maps that range from 1:50,000 to 1:1,000,000 scale. A national digital geologic map database is essential in interpreting other datasets that support numerous types of national-scale studies and assessments, such as those that provide geochemistry, remote sensing, or geophysical data. The SGMC is a compilation of the individual U.S. Geological Survey releases of the Preliminary Integrated Geologic Map Databases for the United States. The SGMC geodatabase also contains updated data for seven States and seven entirely new State geologic...
This coverage includes arcs, polygons, and polygon labels that describe the generalized geologic age of surface outcrops of bedrock of Svalbard. It also includes shorelines.
Geologic units polygon shapefile and coverage of the San Juan Basin.
This thematic map illustrates the median age of people in the United States in 2010; the Median Age for the U.S. is 37 years. Median Age is calculated from the distribution of age by five-year ranges. This data is from Esri's Updated Demographics (2010/2015) database. This thematic map illustrates the median age of people in the United States in 2010; the Median Age for the U.S. is 37 years. Median Age is calculated from the distribution of age by five-year ranges. This data is from Esri's Updated Demographics (2010/2015) database. This map shows Esri's 2010 estimates using Census 2000 geographies. The geography depicts States at greater than 25m scale, Counties at 750k to 25m scale, Census Tracts at 150k...
In many ways, the mountain west (Alaska, Arizona, Colorado, Idaho, Montana, New Mexico, Nevada, Utah, Wyoming) is an energy colony for the rest of the United States: it is rich in energy resources that are extracted to fuel economic growth in the wealthier and more populous coastal regions. Federal agencies and global corporations often behave as if the mountain west is a place to be exploited or managed for the benefit of customers and consumers elsewhere. Yet, the area. is not vast empty space with a limitless supply of natural resources, but rather a fast-growing region with a diverse economic base dependent on a limited supply of water. New decision processes and collaborations are slowly changing this situation,...
This coverage includes arcs, polygons, and polygon labels that describe the generalized geologic age and type of surface outcrops of bedrock of the Far East (China, Japan, Mongolia, North and South Korea, and Taiwan; and parts of Cambodia, Laos, Thailand and Vietnam). It also includes shorelines and inland water bodies.
This coverage includes arcs, polygons, and polygon labels that describe the geologic age and type of surface outcrops of bedrock of the Bangladesh. It also includes shorelines and inland water bodies.
This coverage includes arcs, polygons, and polygon labels that describe the generalized geologic age and type of surface outcrops of bedrock of Southeast Asia (Brunei, Indonesia, Cambodia, Laos, Malaysia, Papua New Guinea, Philippines, Singapore, Solomon Islands and Vietnam; and portions of Australia, China and Taiwan). It also includes shorelines and inland water bodies.
This coverage includes arcs, polygons, and polygon labels that describe the generalized geologic age and rock type of surface outcrops of bedrock of the Australia and New Zealand area (Australia, Fiji, New Caledonia, New Zealand, Tonga and Vanuatu; and portions of Indonesia, Papua New New Guinea and Solomon Islands). It also includes shorelines and inland water bodies.
Microchemistry demographics and development data from wild caught black carp in the Mississippi River basin, 2011-18
Data consists of ploidy, otolith stable isotope analysis and microchemistry, age, weight, sex, length and geolocation data from wild caught black carp (Mylopharyngodon piceus) captured in the Mississippi River basin from 2011 through 2018.
The desert tortoise occurs in two strikingly different desert regimes in the southwestern United States. In the Mojave Desert, rainfall is more irregular and resources are more limited than in the Sonoran Desert. We examined the age structure of tortoise populations from these two deserts to determine whether the difference in resource availability has driven an evolutionary divergence in life history strategies. Age and growth rates strongly reflect the ecological adaptation of the two populations. The oldest Sonoran males reached 54 years, compared to only 43 years in females. The oldest West Mojave (WM) males reached 56 years, compared to only 27 years in females. WM tortoises grew faster than Sonoran ones, and...
Renewable energy adoption in an ageing population: Heterogeneity in preferences for micro-generation technology adoption
Many countries are endeavouring to supply more of their energy from renewable resources. Such countries are also experiencing an aging population with a greater proportion of people aged ≥65 years. This demographic shift may reduce the uptake of renewable energy, if older person households are less inclined to accept change and adopt new technologies. This paper assesses whether such households have different behavioural responses to energy efficiency compared to the rest of society and investigates whether micro-generation renewable energy technologies are less likely to be adopted by these households. It uses conditional logit and mixed logit models to investigate the impact of age of household on primary heating...
Groundwater ages estimated from environmental tracers can help calibrate groundwater flow models. Groundwater age represents a mixture of traveltimes, with the distribution of ages determined by the detailed structure of the flow field, which can be prone to significant transient variability. Effects of pumping on age distribution were assessed using direct age simulation in a hypothetical layered aquifer system. A steady state predevelopment age distribution was computed first. A well field was then introduced, and pumpage caused leakage into the confined aquifer of older water from an overlying confining unit. Large changes in simulated groundwater ages occurred in both the aquifer and the confining unit at high...
Age, Trace Metal, Stable Isotope, and Fatty Acid Data Collected from Sturgeon Captured in the Mississippi and St. Croix Rivers, Minnesota and Wisconsin, 2015-2016. Data
Proposed invasive carp barriers may threaten populations of migratory fishes in the St. Croix National Scenic Riverway and the Mississippi National River and Recreation Area by preventing movements between rivers needed to fulfill life history requirements. Moreover, reproducing populations of invasive carp could alter aquatic food webs and negatively affect mussels and migratory fishes. In this study, nonlethal chemical techniques were used to determine the trophic positions and migratory histories of lake sturgeon (Acipenser fulvescens) captured in the St. Croix and Mississippi rivers. Stable isotope analyses demonstrated differences in trophic position among sturgeon captured in different locations among the...
This dataset describes faults and structural features of the Caribbean region (Anguilla, Antigua and Barbuda, Aruba, Bahamas, Barbados, Belize, British Virgin Islands, Cayman Islands, Colombia, Costa Rica, Cuba, Dominica, Dominican Republic, El Salvador, Grenada, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Jamaica, Martinique, Mexico, Montserrat, Netherlands Antilles, Nicaragua, Panama, Puerto Rico, St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines, Trinidad and Tobago, Turks and Caicos Islands, United States, Venezuela, and the Virgin Islands (named countries may not be completely shown on map)).
This coverage includes arcs, polygons, and polygon labels that describe the generalized geologic age of surface outcrops of bedrock of Europe including Turkey (Albania, Andorra, Austria, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Liechtenstein, Luxembourg, The Former Yugoslav Republic of Macedonia, Malta, Monaco, Netherlands, Norway, Poland, Portugal, Romania, San Marino, Serbia and Montenegro, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, United Kingdom and Vatican City.) It also includes shorelines and inland water bodies.