GEM system

For each reaction in the generated pathway, users can manually select the reactions to be represented by dynamic equations. InitiaUy, the GEM system would automatically search for static reactions based on monomer enzymes found in Brenda and Swiss-PROT databases. Based on the search results, the static part of the model is then generated using the hybrid dynamic/static simulation algorithm detailed below. Finally, the generated pathway model can be used for simulations in E-Ccll System. Users can then specify dynamic equations by selecting an appropriate reaction mechanism and input reaction parameters, or they can program their own set of reaction process description files. 

The catalytic systems described thus far have the advantage of preventing large quantities of gem-chlotinated cyclohexadienones from forming. This type of by-product can, however, always be eliminated with reduciag agents (25,31,32) or acids (33). 

Phase-transfer systems for generating fluorohalocarbenes from the corre spending haloforms are simple and effective with nucleophilic olefins [5J, 54 55, 56, 57, 58, 59] (Table 3 and equations 23 and 24), and the process was extended recently to difluorocarbene [60] Chlorofluorocarbene also can be generated from fluorotrichloromethane and utanium(O) produced in situ (T1CI4 + L1AIH4) Yields of gem-chlorofluorocyclopropanes range from excellent (85% for a. meth ylstyrene) to poor (12% for 1-hexene) [61]... 

FIGURE 2.5. Dynamics of Generic Error Modeling System (GEMS) (adapted from Reason, 1990). 

In acidic electrolytes only lead, because it forms passive layers on the active surfaces, has proven sufficiently chemically stable to produce durable storage batteries. In contrast, in alkaline medium there are several substances basically suitable as electrode materials nickel hydroxide, silver oxide, and manganese dioxide as positive active materials may be combined with zinc, cadmium, iron, or metal hydrides. In each case potassium hydroxide is the electrolyte, at a concentration — depending on battery systems and application — in the range of 1.15 - 1,45 gem"3. Several elec-... 

The steric effect generated by the gem-dimethyl group of the thietane ring on the adjacent sp2 carbon atom makes the cycloaddition in these cases more sluggish compared with those of the parent thietane dioxide (6b)190. These cycloadditions provide a convenient entry into the strained thiabicyclo [2.2.0] hexane system (e.g. 287, 288 equation 107). 

The software is written in the C language on an Atari ST microcomputer (1) and utilizes a GEM graphics user interface which features mouse control, windows, pulldown menus, and pop up alert and data entry boxes. The system could be ported to the IBM PC under the GEM operating system if the need were to arise. 

---