Triac

Thyroid hormone receptors (THRs) are subdivided intoa and P types, each having two isoforms. In rat brain, THR, mRNA is present in hippocampus, hypothalmus, cortex, cerebellum, and amygdala. Thyroxine (l-T (284) and triiodothyronine (l-T ) (285) are endogenous ligands for the THRs. TRIAC (286) is a THR antagonist. Selective ligands for PPARs have yet to be identified (Table 16). 

Silicon-controlled rectifiers (SCR). These arc basictilly thyristors and unless specified, a thyristor will mean an SCR Triacs... 

Unlike an SCR, which is unidirectional, a triac is a bidirectional thyristor switch and conducts in both directions. It can be considered as composed of two SCRs, connected back to back with a single gate, as shown in Figure 6.22(a). Since the thyristor now conducts in both directions there is no positive (anode) or negative (cathode) terminals. 

The triac may, however, have some limitations in handling frequencies higher than normal. In such cases, they can be simulated by using two SCRs in inverse parallel combinations as illustrated in Figure 6.22(b). Now it is known as a reverse conducting thyristor. An SCR has no frequency limitations at least up to ten times the normal. The required voltage and current ratings are obtained by series-parallel connections of more than one thyristor unit. 

Figure 6.22(b) Use of two SCRs in inverse parallel combination to simulate a triac (reverse-conducting thyristors)... 

A solution of 438 mg of diac in methanol (20 ml) and ammonia solution (SG 0.88 20 ml) was iodinated at 0°C with 1.8 ml 1 N iodine solution. The product was isolated in almost theoretical yield in a manner similar to that described for tetrac. After crystallization from 50% (v/v) methanol, triac was obtained as colorless needles which melted over the range 65°C to 90°C according to the rate of heating. The molten form resolidified at about 110°C and finally melted at 180 C to 181°C without decomposition. The compound, dried at 25°C/3 mm over silica gel, contains methanol of crystallization. 

There are reactive softeners, some of which are N-methylol derivatives of long-chain fatty amides (10.241) while others are triazinyl compounds (10.242). The N-methylol compounds require baking with a latent acid catalyst to effect reaction, whereas dichloro-triazines require mildly alkaline fixation conditions. The N-methylol compounds are sometimes useful for combination with crease-resist, durable-press, soil-release and water-repellent finishes. In this context, the feasibility of using silane monomers such as methyltri-ethoxysilane (10.243), vinyltriethoxysilane (10.244), vinyl triace tylsilane (10.245) and epoxypropyltrimethoxysilane (10.246) in crosslinking reactions to give crease-resist properties and softness simultaneously has been investigated [492]. 

Fig. 64 Light dimmer and heating mantle triac power control.

Fatty liver occurs in kwashiorkor, probably due to lack of protein in the diet, which reduces the synthesis of the structural protein for VLDL (apolipoprotein B). The increased triacylglycerol produced in the liver from fatty acids removed from the blood (i.e. the inter-tissue triac-... 

Oxidation of alcohols to the corresponding carbonyl compounds using triace-toxyperiodinane. 

Tiratricol All products containing tiratricol 11/22/2000 Tiratricol also known as triiodothyroacetic acid or TRIAC, is a potent thyroid hormone that may result in serious health consequences... 

The reduction of /1-hydroxy ketones with a tetramethylammonium triace-toxyborohydride-anhydrous acetic acid system yielded the anti diols via the transition state (TA). The stereochemistry of the 1,3-diols was assigned by using H NMR coupling constants after their conversion to the corresponding cyclic acetonide. 

Abdel-Magid, A. F. Carson, K. G. Harris, B. D. Maryanoff, C. A. Shah, R. D. Reductive Amination of Aldehydes and Ketones with Sodium Triace-toxyborohydride. Studies on Direct and Indirect Reductive Amination Procedures, J. Org. Chem. 1996, 67, 3849. 

Lead Triace oxy-(4-trifluoromethyl-phenyl)- ElOa, 602 (Educt) ElOb. 1 (Educt)... 

V (usually DC but sometimes AC) Switched Typically up to 240V AC only SSR (solid-state relay or triac)... 

The reactions of tris(2-hydroxyphenyl)amine with trichloro-, trimethoxy- or triace-toxysilanes in boiling toluene afford the corresponding Si-substituted derivatives instead... 

Tandem lesion, where C(8) of G is bound to the methyl group of T Triace loneamine-N-oxyl... 

Partial methacrylation of the mixture of triacetoxymethyl- and triace-toxyphenylsilanes with glycolmethacrylate (MEG) ... 

Fig. 32.. Production and methacrylation diagram of triacetoxymethyl- and triace-toxyphenylsilanes 1,9- synthesis reactors 2-4, 8, 10, 11 - batch boxes 5, 12-coolers 6, 13- receptacles 7 - neutraliser...

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