Electronic communication Subject

The first calculations on a two-electron bond was undertaken by Heitler and London for the H2 molecule and led to what is known as the valence bond approach. While the valence bond approach gained general acceptance in the chemical community, Robert S. Mulliken and others developed the molecular orbital approach for solving the electronic structure problem for molecules. The molecular orbital approach for molecules is the analogue of the atomic orbital approach for atoms. Each electron is subject to the electric field created by the nuclei plus that of the other electrons. Thus, one was led to a Hartree-Fock approach for molecules just as one had been for atoms. The molecular orbitals were written as linear combinations of atomic orbitals (i.e. hydrogen atom type atomic orbitals). The integrals that needed to be calculated presented great difficulty and the computations needed were... 

The Patriot Act expands the definition of pen registers and trap and trace devices for use with electronic communications (such as e-mail). Police officers can now determine the routing and addressing information of outgoing e-mail (but not the actual contents of the communication), while a tap and trace device permits similar information to be gathered from the incoming messages that the subject receives [114, 116]. 

Radome (radiation dome) is used to cover a microwave electronic communication antenna. It protects the antenna from the environment such as the ground, underwater, and in the air vehicles. To eliminate any transmission interference, it would be desirable not to use a radome since transmission loss of up to 5% occurs with the protective radome cover material. The radome is made to be as possibly transparent to electromagnetic radiation and structurally strong. Different materials can be used such as plastics, wood, rubber-coated air-supported fabric, etc. To meet structural load requirements such as an aircraft radome to ground radomes subjected to wind loads, use is made of RPs that are molded to very tight thickness tolerances. Fig. 4.56 shows a schematic of a typical ground radome that protects an antenna from the... 

Electronic communication is also an advantage to the chemical educator. The rapid acc tance of e-mail means that any faculty member who is connected to the Internet has access to a variety of professional information and consultation that would not have been dreamed of in the past. Discussion lists, such as CHEMED-L, bring together chemists from all over the world, and informal e-mail lists devoted to special topics are proliferating. It has become routine for faculty members to address questions about pedagogy or subject matter to these lists and receive not Just an answer to their query, but often an in-depth discussion of the topic. 

An electronic communication board on which universities can post questions regarding technical or other subjects could be beneficial. Compare this with the "Ventilation communication board", which is co-ordinated by Pierre Mouset-Jones. Questions dealing with education, research, internships, jobs, etc. could then easily be distributed. 

The ionosphere is subject to sudden changes resulting from solar activity, particularly from solar emptions or flares that are accompanied by intense x-ray emission. The absorption of the x-rays increases the electron density in the D and E layers, so that absorption of radio waves intended for E-layer reflection increases. In this manner, solar flares dismpt long-range, ionospheric bounce communications. 

A pen register is a mechanical device that records the numbers dialed on a telephone by monitoring the electrical impulses caused when the dial on the telephone is released. It does not overhear oral communications and does not indicate whether calls are actually completed. They can be used to record the telephone number dialed by the subject of the surveillance. Trap and trace devices, are used to record the telephone numbers of incoming calls received by the subject [114]. They are also used to capture source and address information for computer conversations (electronic mail) [115]. 

Narrowly focused, the tenets of 21 CFR 11 are indisputable that firms must establish and maintain the integrity of their electronic information. What has been lost is the clear indication of which electronic information the requirements apply to. In my opinion, data generated outside a computerized system, that are manipulated by that system and are ultimately available in hard copy should not be subject to this ruling. Validation of the computerized system should be more than sufficient to establish that the final documentation accurately reflects the input information. In that instance, the computerized system is little more than a tool whose functionality can be readily established, yet firms are endeavoring to assure 21 CFR 11 compliance for numerous systems in which the computer is little more than an adjunct to the cGMP activity and corresponding hard copy. Batch record preparation, SOP and test method archives, and many process equipment control systems are examples of systems in which requirements for 21 CFR 11 compliance appear excessive. A system that processes or communicates data or records and subsequently retains and stores hard copies should not be subject to the 21 CFR 11 requirements. Far too many systems are being unnecessarily held to the very restrictive portions of 21 CFR 11. Electronic record retention as defined in 21 CFR 11 has its place, but not necessarily in every computerized system used within the industry. 

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