The American Society for Testing and Materials (ASTM)
ASTM International is one of the largest voluntary standards development organizations in the world-a trusted source for technical standards for materials, products, systems, and services. Known for their high technical quality and market relevancy, ASTM International standards have an important role in the information infrastructure that guides design, manufacturing and trade in the global economy.
The Phytotron of NCSU (USA) . The North Carolina State University Phytotron : link
The NCSU Phytotron contains 57 growth chambers and 5 greenhouses and space is available for use by off-campus researchers.
Closing the System
Only in the late 1940's when human comfort air conditioning became fairly common, and the relatively high output slimline fluorescent lamp was developed, did closed plant growth chambers with complete environmental control become possible. The great advantage of a phytotron lies in the control of many environmental factors simultaneously. The composition of the air, the temperature, the humidity, the daylength, light spectrum, root zone temperature, and nutrition can all be programmed so that the effects of a change in one factor can be isolated in ways that are not possible in field or greenhouse experiments. The first phytotron, the Earhart Laboratory, was built by botanist F. W. Went at the California Institute of Technology in 1948. With 54 separate air-conditioned and artificially lighted rooms programmed for a range of conditions, the facility had great flexibility for setting different combinations of temperature, light, and humidity.
NCSU Builds Phytotron
In 1968 another phytotron was constructed in the United States, this one at NCSU. Formally called the Southeastern Plant Environment Laboratory, the NCSU phytotron is a leading center for controlled environment research in the United States, and one of the largest such facilities in the world. With 60 artificially lighted growth chambers of various sizes, 9 photoperiod rooms, and 5 temperature-controlled greenhouses, the phytotron lends itself to an enormous number of experiments - usually between 50 and 70 different projects each year. The range of subjects is broad, including very basic studies of plant physiology as well as practical problems of crop species. Unlike a number of other phytotrons which maintain all chambers and greenhouses at set environmental conditions, the NCSU Phytotron provides customized environmental programming for each experiment. Only eight of the large walk-in chambers and the five greenhouses are operated at set conditions on a permanent basis to serve many experimenters simultaneously.
Not Just Plants
Not Just Plants
eAlthough the controlled-environment facilities were initially designed for plant research, they are also useful for many kinds of animal and insect studies where control of daylength and temperature is desirable. Zoologists and entomologists have used the NCSU Phytotron facility for the study of lizards, ghost crabs, woodcocks, pine voles, mice, wood roaches, grasshoppers, bean beetles, fruit weevils, spruce bud mites, house dust mites, gypsy moths, and fish.
The Phytotron is used by scientists from NCSU departments in the Colleges of Agriculture and Life Sciences, Forest Resources, and Physical and Mathematical Sciences, as well as from the U.S. Department of Agriculture, many other U.S. and overseas universities, and some private industries.
With such intensive demand, the centralized facility is used fully and very efficiently. A full-time staff of 10 includes the Director, Dr. Carole Saravtz, and Director Emeritus, Dr. Robert J. Downs, as well as the Phytotron manager, technicians, and mechanical and electronics experts who help investigators with the development of special equipment and instrumentation. Among the environmental factors that can be controlled in the phytotron are:
- - air temperature rootzone temperature daylength (photoperiod) irradiance and spectral quality of light carbon dioxide concentration relative humidity
- - nutrient concentration and pH
The Seed Germination Laboratory
Twelve germinators are available which can be set to a range of constant and alternating temperatures. Red and far-red sources of known spectral energy distribution are available for light-requiring seeds. Two large incubators can be equipped with light sources and can provide low temperatures for stratification and vernalization treatments to hasten maturity.
Root Zone-Hydroponic - Units
Continuous flow liquid culture units automatically control pH level and temperatures between 10 ° and 35 ° C
(50 ° and 95 ° F). With individual units available, the effects of different nutrient treatments can be studied simultaneously.
(50 ° and 95 ° F). With individual units available, the effects of different nutrient treatments can be studied simultaneously.
Plant Pathogen Isolation Area
The effects of plant pathogens can be studied in the four walk-in chambers and laboratory set aside for this purpose. Contamination of other areas of the Phytotron is prevented by keeping air pressure lower than in other sections, and equipping the air exhaust system with spore-trapping filters. Automatic watering and view ports in chamber doors reduce personnel movement and potential contamination in these rooms to the minimum.
Cold Chambers
Constant, daily or programmed chilling temperature conditions are possible in two small walk-in chambers. Temperatures can be lowered to 39 ° F (4 ° C) in the light and 32 ° F (0 ° C) in the dark. These rooms are used for studies of environmental physiology, chilling resistance in crops, and chemical means of freeze protection.
High Intensity Light Rooms
To meet increased demands for studies of the effects of high intensity light levels approaching natural sunlight, two reach-in chambers have been fitted with super metal halide lamps which can be used alone or in combination with incandescent lamps and/or high pressure sodium lamps. Intensities of 1000 to 2000 mol m-2 s-1 can be reached in these rooms.
The Academic phrase bank__link
is a general resource for academic writers. It aims to provide you with examples of some of the phraseological "nuts and bolts" of writing organised under the headings to the left. It was designed primarily with international students whose first language is not English in mind. However, if you are a native speaker writer, you may still find parts of the material helpful.
The phrases can be used simply to assist you in thinking about your writing, or they can be used in your own work where this is appropriate. In most cases a certain amount of creativity will be necessary when you do this. It is also possible to transfer some of the words used in particular phrases to others. The phrases are content neutral and generic in nature; in using them, therefore, you are not stealing other people's ideas and this does not constitute plagiarism.
Users will need to be aware that Phrasebank is not discipline specific, and it does not claim to be comprehensive.
Source: john.morley@manchester.ac.uk
The phrases can be used simply to assist you in thinking about your writing, or they can be used in your own work where this is appropriate. In most cases a certain amount of creativity will be necessary when you do this. It is also possible to transfer some of the words used in particular phrases to others. The phrases are content neutral and generic in nature; in using them, therefore, you are not stealing other people's ideas and this does not constitute plagiarism.
Users will need to be aware that Phrasebank is not discipline specific, and it does not claim to be comprehensive.
Source: john.morley@manchester.ac.uk
