laboratory benches tables image
simplysass
components of model science laboratory
Answer
To a large degree, it depends on the type of work to be done, but in general:
- No less than one electrical outlet every 1 foot (30cm), and independant circuits every 6 feet (2m). If the lab is located in the US, it will also need 220-240V circuits in addition to 110V. The idea here is to allow for equipment to be installed and moved without having to call an electrician in.
- Adequate aisle space: at least 3 feet (1m) of free aisle space in addition to what is taken up by someone working at a bench. There should always be room for a cart to roll by, no matter how many people are working in the lab. One easy way to ensure this is to use L-shaped benches.
- Adequate ventillation. This may be fume hoods, laminar flow hoods, snorkle ventillation, glove boxes, or just frequent change-over of the room air depending on the type of work being done. Typically, labs are maintained at negative pressure relative to surrounding areas, to ensure that any fumes do not enter the rest of the building.
- Tight control over air temperature and humidity, as appropriate to the type of work being done.
- Easy to use and easy to understand waste disposal system with separation of incompatible types of waste. For example, this could be drains aqueous wastes leading to a pre-treatment system, collection barrels for different types of solvents and collection bins for contaminated towelling. There must be a process such that wastes are collected and disposed of efficiently and correctly.
- Emergency equipment as appropriate to the work being done, for example, showers and eyewashes, fire extinguishers, first aid supplies, emergency exits, emergency power/lighting.
- Adequate storage for equipment and supplies (glassware, hotplates, stir plates, wipes, gloves, etc.). Appropriate cabinets for any chemical or biological materials (vented cabinets, refrigerator, freezer).
- If balances are used, they are placed on heavy balance tables.
That's all I can think of at the moment.
To a large degree, it depends on the type of work to be done, but in general:
- No less than one electrical outlet every 1 foot (30cm), and independant circuits every 6 feet (2m). If the lab is located in the US, it will also need 220-240V circuits in addition to 110V. The idea here is to allow for equipment to be installed and moved without having to call an electrician in.
- Adequate aisle space: at least 3 feet (1m) of free aisle space in addition to what is taken up by someone working at a bench. There should always be room for a cart to roll by, no matter how many people are working in the lab. One easy way to ensure this is to use L-shaped benches.
- Adequate ventillation. This may be fume hoods, laminar flow hoods, snorkle ventillation, glove boxes, or just frequent change-over of the room air depending on the type of work being done. Typically, labs are maintained at negative pressure relative to surrounding areas, to ensure that any fumes do not enter the rest of the building.
- Tight control over air temperature and humidity, as appropriate to the type of work being done.
- Easy to use and easy to understand waste disposal system with separation of incompatible types of waste. For example, this could be drains aqueous wastes leading to a pre-treatment system, collection barrels for different types of solvents and collection bins for contaminated towelling. There must be a process such that wastes are collected and disposed of efficiently and correctly.
- Emergency equipment as appropriate to the work being done, for example, showers and eyewashes, fire extinguishers, first aid supplies, emergency exits, emergency power/lighting.
- Adequate storage for equipment and supplies (glassware, hotplates, stir plates, wipes, gloves, etc.). Appropriate cabinets for any chemical or biological materials (vented cabinets, refrigerator, freezer).
- If balances are used, they are placed on heavy balance tables.
That's all I can think of at the moment.
microwave radiation emitter?
Shasato
I need a device that will emit controlled amounts of microwave radiation under laboratory settings.
The target is 5 Saccharomyces cerevisiae (baker's yeast) cells
Answer
Microwave energy is radiated from an antenna. The antenna has an efficiency and a directional pattern, so these can be used along with the power of the source to determine the power density in a given direction and distance as mW/cm^2. This is similar to the light from a focused lamp (a torch) being shone on a table. Also the correct pattern only forms at a few wavelengths out from the antenna. A typical antenna could be a horn or parabola shape, or maybe a simple dipole or monopole. You need to know the power level and the frequency (wavelength) then you can go further. I envisage a source above a bench radiating down so that the power density is nn mW/cm^2 at the bench surface within a certain area. Levels less than 10mW/cm^2 are not considered hazardous in some regulations. There are electro-magnetic radiation safety regulations nevertheless to comply with. You would not look into the beam (back into the antenna) even so, as the density can vary, and the eyeballs are very easily poached.. I should mention that the dimensions of all these things are related to wavelength, so that is a practical factor too. It would tend to mean frequencies above 10GHz.
At levels above this it needs to be totally enclosed, and really we are talking about a laboratory microwave oven of some kind (second link). These are like a kitchen microwave with more control and fume extraction etc. The first link below may help too, especially the references.
The power level per unit area can be verified by using a calibrated antenna, with a suitable power measuring device. This is as watts per unit area. How you can relate that to 5 cells I don't know, as the power absorbed depends on structure, material (see first link).
In some cases the heating effect of the electro-magnetic power can be used to measure power, as in a calorimeter. In this case the power in watts to raise a unit mass a number of degrees in temperature in a given time. If you had a cake to cook, water to boil this is quite relevant. A solution of cells could be similar - say 1g of a solution of cells. Measure the power of an oven this way, using a known mass of water. However the power level of microwave ovens is constant - only on or off. The adjustment is by cycling it on and off, like the kitchen types. However it may be cycled according to a temperature sensor to control the temperature in a volume of liquid, and also cycle more rapidly to provide a more stable heating cycle.
Note that a volume of water in the oven absorbs some energy, so provides some sort of control too.
Microwave energy is radiated from an antenna. The antenna has an efficiency and a directional pattern, so these can be used along with the power of the source to determine the power density in a given direction and distance as mW/cm^2. This is similar to the light from a focused lamp (a torch) being shone on a table. Also the correct pattern only forms at a few wavelengths out from the antenna. A typical antenna could be a horn or parabola shape, or maybe a simple dipole or monopole. You need to know the power level and the frequency (wavelength) then you can go further. I envisage a source above a bench radiating down so that the power density is nn mW/cm^2 at the bench surface within a certain area. Levels less than 10mW/cm^2 are not considered hazardous in some regulations. There are electro-magnetic radiation safety regulations nevertheless to comply with. You would not look into the beam (back into the antenna) even so, as the density can vary, and the eyeballs are very easily poached.. I should mention that the dimensions of all these things are related to wavelength, so that is a practical factor too. It would tend to mean frequencies above 10GHz.
At levels above this it needs to be totally enclosed, and really we are talking about a laboratory microwave oven of some kind (second link). These are like a kitchen microwave with more control and fume extraction etc. The first link below may help too, especially the references.
The power level per unit area can be verified by using a calibrated antenna, with a suitable power measuring device. This is as watts per unit area. How you can relate that to 5 cells I don't know, as the power absorbed depends on structure, material (see first link).
In some cases the heating effect of the electro-magnetic power can be used to measure power, as in a calorimeter. In this case the power in watts to raise a unit mass a number of degrees in temperature in a given time. If you had a cake to cook, water to boil this is quite relevant. A solution of cells could be similar - say 1g of a solution of cells. Measure the power of an oven this way, using a known mass of water. However the power level of microwave ovens is constant - only on or off. The adjustment is by cycling it on and off, like the kitchen types. However it may be cycled according to a temperature sensor to control the temperature in a volume of liquid, and also cycle more rapidly to provide a more stable heating cycle.
Note that a volume of water in the oven absorbs some energy, so provides some sort of control too.
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