Search results
Results from the WOW.Com Content Network
A tank of liquid nitrogen, used to supply a cryogenic freezer (for storing laboratory samples at a temperature of about −150 °C or −238 °F) Controlled-rate and slow freezing, also known as slow programmable freezing (SPF), [18] is a technique where cells are cooled to around -196 °C over the course of several hours.
Soil contaminated with radioactive elements that leaked from Japan's Fukushima Daiichi nuclear power plant was contained through ground freezing. [1]A project in Boston known as the Big Dig used ground freezing during some of its tunneling, to allow its wide tunnels to be built under or through soil that supported existing infrastructure that would have been difficult or expensive to support ...
Nitrogen deficiency is a deficiency of nitrogen in plants. This can occur when organic matter with high carbon content, such as sawdust, is added to soil. [1] Soil organisms use any nitrogen available to break down carbon sources, making nitrogen unavailable to plants. [1] This is known as "robbing" the soil of nitrogen.
Nitrogen directly affects soil respiration in several ways. Nitrogen must be taken in by roots to promote plant growth and life. Most available nitrogen is in the form of NO 3 −, which costs 0.4 units of CO 2 to enter the root because energy must be used to move it up a concentration gradient. Once inside the root the NO 3 − must be reduced ...
The total nitrogen content depends largely on the soil organic matter content, which in turn depends on texture, climate, vegetation, topography, age and soil management. [40] Soil nitrogen typically decreases by 0.2 to 0.3% for every temperature increase by 10 °C. Usually, grassland soils contain more soil nitrogen than forest soils, because ...
Since then, machines that freeze biological samples using programmable steps, or controlled rates, have been used all over the world for human, animal, and cell biology – 'freezing down' a sample to better preserve it for eventual thawing, before it is deep frozen, or cryopreserved, in liquid nitrogen. Such machines are used for freezing ...
Soil Kit can be picked up for free at your Extension office, and the kit comes with a prepaid shipping label to mail in your soil sample. The cost of the SoilKit sample is $29.95 per sample.
Soil gases (soil atmosphere [1]) are the gases found in the air space between soil components. The spaces between the solid soil particles, if they do not contain water, are filled with air. The primary soil gases are nitrogen, carbon dioxide and oxygen. [2] Oxygen is critical because it allows for respiration of both plant roots and soil ...