Sentences with phrase «nitrogen concentration»

Aside from the obvious difference that humans are not altering the nitrogen concentration of the atmosphere, as they are with (several) greenhouse gases, such a question boggles the mind in terms of the mindset that must exist to ask it in a public congressional hearing in the first place.

Elevated atmospheric CO2 is associated with decreased plant nitrogen concentration, and therefore decreased protein, in many crops, such as barley, sorghum, and soy.210, 211,212,213 The nutrient content of crops is also projected to decline if soil nitrogen levels are suboptimal, with reduced levels of nutrients such as calcium, iron, zinc, vitamins, and sugars, although this effect is alleviated if sufficient nitrogen is supplied.214 Fourth, farmers are expected to need to use more herbicides and pesticides because of increased growth of pests215, 216,217,218 and weeds219, 220 as well as decreased effectiveness221 and duration222of some of these chemicals (Ch.

Decreases in nitrogen concentration have also been reported for herbaria plant specimens in response to the increases in Ca during the twentieth century [50].

Liang and his group analyzed nine environmental factors, including solar radiation, wind speed, precipitation, nitrogen concentration, water temperature and water quality in Lake Erie from 2002 to 2012.

Based on measurements of 45,000 individual plants from 3,680 species, and using high - tech statistical mapping protocols, the team created global maps of plant traits including leaf nitrogen concentration, leaf phosphorus concentration, and specific leaf area (a measure of area displayed to intercept light per unit investment in leaf biomass).

For breastfed infants, there is no evidence of an increased risk of methemoglobinemia from maternal ingestion of water with nitrate nitrogen concentrations as high as 100 ppm, because these mothers do not produce milk with high nitrate concentrations.16 Furthermore, the predominant organism in the gastrointestinal tract (Lactobacillus species) of the breastfed infant does not reduce nitrate to nitrite (see following section).14

Boiling water with nitrate nitrogen concentrations of < 10 ppm for 1 minute generally is sufficient to kill microorganisms without over concentrating nitrate.21

Mr. Bellone pointed to a recent report that showed nitrogen concentrations in one of Long Island's three aquifers rose by 40 percent between 1987 and 2013, while levels in the island's largest aquifer rose by 80 percent during that same time span.

Rules limiting nutrient runoff from farms and wastewater treatment plants helped to decrease nitrogen concentrations in the bay by 23 percent since 1984.

Evidence from the samples they gathered and tested showed that human wastewater nitrogen from septic systems was a major contributor to the high nitrogen concentrations in the estuary and downstream coastal reefs, the latter representing the northernmost extent of coral growth in South Florida.

These differences may relate to the observed differences in nitrogen concentrations.

In order to understand the role of nutrient cycling across the sediment water interface sediment cores are routinely collected and analysed for phosphorus and nitrogen concentrations.

Not exact matches

... A number of scientific studies indicate that most global warming in recent decades is due to the great concentration of greenhouse gases (carbon dioxide, methane, nitrogen oxides and others) released mainly as a result of human activity... Doomsday predictions can no longer be met with irony or disdain.

Concentrations of total nitrogen were 10 %, nitrate 30 % and nitrite 87 % lower in organic compared to conventional crops.

When serving «nitrate» vegetables, the levels of nitrates in Organics are reduced though not 100 percent eradicated (Nitrates are naturally occurring and farming without using nitrogen fertilizers does not eliminate nitrate concentration).

When serving «nitrate» vegetables, the levels of nitrates in Organics are significantly reduced though not 100 percent eradicated (Nitrates are naturally occurring and farming without using nitrogen fertilizers does not eliminate nitrate concentration).

Most reported cases have been ascribed to the use of contaminated well water for preparation of infant formula.1 — 3 Fifteen million families in the United States obtain their drinking water from unregulated wells.4 In a survey of 5500 private water supplies from 9 Midwestern states, 13 % of the wells were found to have nitrate concentrations > 10 mg / L or 10 ppm nitrate nitrogen, 5 the federal maximum contaminant level.6 It is estimated that 2 million families drink water from private wells that fail to meet the federal drinking - water standard for nitrate, and 40000 infants younger than 6 months live in homes that have nitrate - contaminated water supplies.4 In urban areas, municipal wastewater - treatment discharges (a source of nutrients) on surrounding farmland aggravate the problem.7

The proportion of diesel vehicles registered in Leipzig however rose from 19 to 26 % between 2010 and 2016 — with negative consequences: While black carbon and the number concentration of ultrafine particles decreased, the concentration of gaseous nitrogen oxides (NOx) is stagnant and is still too high.

To assess the influence of phosphorus on nitrogen removal, the researchers used a comparative approach — they examined the differences between how much nitrogen goes into lakes and how much comes out downstream — coupled with time - series analyses of nitrogen and phosphorus concentration in large lakes.

«And we've shown that there are a number of times where the nitrogen dioxide (NO2) concentrations exceed the EU hourly mean limits for outdoor air quality.»

At the end of the study, children who lived in neighborhoods with the highest concentrations of nitrogen dioxide and particulates had experienced greater declines in insulin sensitivity and had signs of impaired pancreatic beta cells, which produce insulin.

Earth's atmosphere is mostly nitrogen and oxygen, but the exact concentration varies with altitude.

In a typical urban area with a high level of background air pollution — for example, around 15 micrograms of fine particulate matter (PM2.5) per cubic metre, or a nitrogen dioxide concentration around 33 micrograms per cubic metre — an extra 300 trees per square kilometre was associated with around 50 fewer emergency asthma cases per 100,000 residents over the 15 year study period.

These types of plants have been associated with environments that supply high concentrations of essential nutrients, such as nitrogen and phosphorus, and warm - wet climatic conditions, both of which help plants photosynthesize more productively.

They rapidly detect and continuously respond to extremely small changes in the concentrations of gases including ammonia, carbon dioxide, and nitrogen oxide.

When he tested soils from the experimental plots, he saw soil organic carbon concentrations rise gradually with increases in nitrogen fertilization at soil depths from 0 to 6 inches, although not at deeper ones.

Previous modelling efforts to resolve the paradox by loading the early atmosphere with greenhouse gases assumed that it has always had the same concentration of nitrogen.

The chemical composition of the microalgae is not an intrinsically constant factor, but varies over a wide range in accordance with the different cultivation factors such as temperature, light (intensity, wavelength and photoperiod), pH of the medium, supply of CO2, concentration and type of nutrients, source and concentration of nitrogen, salinity and growth phase.

With regard to the air quality in cities with high concentrations of nitrogen oxides, this property of Arabidopsis thaliana plants could contribute significantly to the reduction of NO and thus improve air quality.

In nature, bacteria flourish best in the presence of high concentrations of phosphates and nitrogen,» says Netzer.

Since changes in the soil nitrogen cycle are driven by microbes, could bacteria associated with invasive species not only be responsible for the observed changes in soil nutrient concentrations, but also for enabling the continued growth and persistence of the invader species?

«But what we do see in the analysis of the data is an increase in temperatures and chlorophyll concentration across the bay and a changing relationship between nitrogen and chlorophyll — an indicator of algae growth and water quality — as those waters warm.»

Their analysis, which could discern human - derived nitrogen from natural nitrogen fixation, revealed that the oceanic nitrate concentration increased significantly over the last 30 years in surface waters of the North Pacific due largely to the enhanced deposition of nitrogen from the atmosphere.

Their assessment revealed a consistent picture of increasing nitrate concentrations, the magnitude and pattern of which can only be explained by the observed increase in atmospheric nitrogen deposition.

The concentration of nitrogen trifluoride in the atmosphere is about 0.5 part per trillion, making it very hard to measure.

Researchers at the University of Gothenburg have now revealed that the concentration of nitrogen in plants» tissue is lower in air with high levels of carbon dioxide, regardless of whether or not the plants» growth is stimulated.

The models showed that thinner carbon nanotubes with a relatively high concentration of nitrogen would perform best, as oxygen atoms readily bond to the carbon atom nearest the nitrogen.

«It is true that there are other factors (such as volcanism, the changes in the orbit and the axis of the Earth, the solar cycle), but numerous scientific studies indicate that most of the global warming in recent decades is due to the large concentration of greenhouse gases (carbon dioxide, methane, nitrogen oxide and others) mainly emitted due to human activity.»

Decreasing concentrations of dissolved iron do not coincide with the occurrence of oxygen but with the increase of dissolved nitrogen compounds.

Ammonia is an abundant constituent in motor vehicle emissions, and its conversion to nitrogen oxides could result in increases in harmful ozone concentrations.

Soil had the lowest remediation of phosphorus and highest concentration of phosphorus in its effluent, and was similar in nitrogen removal efficiency to slate.

During the experiment, concentrations of CO and nitrogen gases were varied across a range of pressures.

European Union rules set a maximum hourly concentration of nitrogen dioxide, which, in towns and cities, mainly comes from road traffic.

The specialized instruments onboard the aircraft sampled the plume for aerosol particle size distribution and composition as well as concentrations of pollutant gases such as sulfur dioxide, nitric oxide, nitrogen dioxide, ozone, and volatile organic compounds (VOCs).

In one sentence: Scientists at Pacific Northwest National Laboratory determined that high concentrations of nitrogen oxides influence the creation of the brown haze that hangs over the world's megacities, providing new insights that can create higher accuracy climate and atmospheric models.

Relative growth rates, carbon, nitrogen, and the C: N ratio in tissue samples were influenced by higher concentrations of NH 4 +.

Working without chemicals or nitrogen / oxygen separators to manipulate the concentration of oxygen, the system works within the natural / breathable atmosphere to produce benefits like those you can get from conventional aerobic and anaerobic exercise.

The researchers» analysis found organic grains and produce to have higher concentrations of antioxidants, lower levels of cadmium and nitrogen compounds and fewer pesticide residues.

One measured fluid, electrolyte, and renal indices of hydration over eleven days of caffeine consumption in human subjects, finding that doses of up to 6 mg caffeine per kilogram of body weight had no effect on body mass, urine osmolality (urine concentration), urine specific gravity (concentration of excreted materials in urine), urine color, urine volume, sodium excretion, potassium secretion, creatinine content, blood urea nitrogen (forms when protein breaks down), and serum levels of sodium and potassium.

CRI is diagnosed by looking at the levels of two waste products in the bloodstream, blood urea nitrogen (BUN) and creatinine, as well as the urine concentration.