EDS Spectral Artifacts / Sum Peaks: A Reminder

Abstract

flllCROf COPY 101salts, the fluorescent caEcium channel ligand BODtPY FL verapamil, and the salts of the calcium indicators Fura Red, Fluo-4, and Oregon Green BAPTA-1. It should be noted that measuring solvents like methanol with a pipette can cause slightly imprecise volumes because of the high vapor pressure. In general, this method can also be used to prepare alEquots of drugs like receptor Ilgands or ion channel blockers. Water Recirculator (Chiller) Maintenance 1Owen Mills Michigan Technological institute opmills@mtu.edu In my mind two things commonly cause problems for electron microscopes. One is vacuum, and the other is cooling water. It is really not that they are trouble, but rather that extra maintenance is involved. The maintenance of water redrafting systems will be discussed in this note.A water recirculator is really a heat exchanger that operates on a basic heat transfer principle. The process cooiing water within the recirculating system is forced through the scope by a pump. Heat is transferred to the process cooEing water as it flows through the microscope lenses, power supplies, and diffusion pump. The process cooling water then flows back through a heat exchanger inside the water recirculator. The total heat is transferred through this heat exchanger into one of two cooling sources: 1. Refrigerated cooling system (evaporator) 2. Non-refrigerated cooiing system (water-to-water heat exchanger)In a refrigerated water recircuiating system, ihe total heat (heat from the microscope plus heat from the mechanical compressor) is transferred through the evaporator by refrigerant into a second heat exchanger known as a condenser A condenser may be air coofed or it may be water coded* An air cooled condenser wili transfer the totai heat into the surrounding ambient air. A water cooled condenser will transfer the total heat into an in-house source of cooling water. The typical temperature range for the condenser water circuit is 50-85In a non-refrigerated water recirculating system, the total heat is transferred through the water-to-water heat exchanger directly into an in-house source of cooling water. The typical temperature range for the water-to-water heat exchanger circuit is 40-55^.Concerning maintenance, the tank water is checked weekly to insure a proper operating level. ]t is also a good idea to check the pH tevel of the water to make sure that it remains neutral. When it becomes dirty, it is drained and refilled with clean water. This occurs about every two years. After the system is drained, the intake filter is cleaned or replaced, A large ultrasonic cleaner can be used to clean the intake filters. Since the intake is directly before the pump, and in order to prevent pump failure, the water pump should always be primed by manually filling the intake hose before installing the filter. Distilled water is used in all systems, and mineral buildup has not been a problem. Except for one scope, all the supply hoses are opaque. Algae problems in that scope chiller are treated with Chlorarnine T (Sigm...