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Newly formed

In this experiment a week of target bombardment was required to produce a single fused nucleus. The team confirmed the existence of element 109 by four independent measurements. The newly formed atom recoiled from the target at predicted velocity and was separated from smaller, faster nuclei by a newly developed velocity filter. The time of flight to the detector and the striking energy were measured and found to match predicted values. [Pg.167]

The newly formed phosphite triester linkage is unstable to acids and bases and is immediately oxidized to a stable phosphate triester (step 4). A solution of iodine, water, 2,6-dimethylpyridine, and tetrahydrofuran is commonly used. The oxidation is usually complete within 30 seconds. [Pg.223]

The reaction of vinyloxiranes with malonate proceeds regio- and stereose-lectively. The reaction has been utilized for the introduction of a 15-hydroxy group in a steroid related to oogoniol (265)(156]. The oxirane 264 is the J-form and the attack of Pd(0) takes place from the o-side by inversion. Then the nucleophile comes from the /i-side. Thus overall reaction is sT -StM2 type, in the intramolecular reaction, the stereochemical information is transmitted to the newly formed stereogenic center. Thus the formation of the six-membered ring lactone 267 from 266 proceeded with overall retention of the stereochemistry, and was employed to control the stereochemistry of C-15 in the prostaglandin 268[157]. The method has also been employed to create the butenolide... [Pg.325]

Conjugation of the newly formed double bond with the carbonyl group stabilizes the a p unsaturated aldehyde provides the driving force for the dehydration and controls Its regioselectivity Dehydration can be effected by heating the aldol with acid or base Normally if the a p unsaturated aldehyde is the desired product all that is done is to carry out the base catalyzed aldol addition reaction at elevated temperature Under these conditions once the aldol addition product is formed it rapidly loses water to form the a p unsaturated aldehyde... [Pg.772]

Newly formed ions (CH4 +) collide several times with neutral molecules (CH4) to give carbonium ions (Figure 1.2b). The substance (M) to be investigated is vaporized into... [Pg.2]

The rapid transfer of heat and the mechanics of blowiag the bottie creates both thermal and mechanically iaduced stresses ia the newly formed bottie. To reheve the stresses, the newly formed botties ate put through an annealing process. [Pg.451]

This mechanism not only accounts for the substitution of the more labile chlorine atom on the polymer chain, it also results in the elimination of a new potential initiation site by moving the double bond out of conjugation with any adjacent chlorine atoms. The newly formed C—O or C—S bonds, with AH > 484 kJ/mol (100 kcal/mol), are significantly more thermally stable than even the normal C—Cl bonds in PVC at about 411 kj/mol (85 kcal/mol) (11). [Pg.546]

Stabilization Mechanism. Zinc and cadmium salts react with defect sites on PVC to displace the labHe chloride atoms (32). This reaction ultimately leads to the formation of the respective chloride salts which can be very damaging to the polymer. The role of the calcium and/or barium carboxylate is to react with the newly formed zinc—chlorine or cadmium—chlorine bonds by exchanging ligands (33). In effect, this regenerates the active zinc or cadmium stabilizer and delays the formation of significant concentrations of strong Lewis acids. [Pg.549]

The newly formed short-chain radical A then quickly reacts with a monomer molecule to create a primary radical. If subsequent initiation is not fast, AX is considered an inhibitor. Many have studied the influence of chain-transfer reactions on emulsion polymerisation because of the interesting complexities arising from enhanced radical desorption rates from the growing polymer particles (64,65). Chain-transfer reactions are not limited to chain-transfer agents. Chain-transfer to monomer is ia many cases the main chain termination event ia emulsion polymerisation. Chain transfer to polymer leads to branching which can greatiy impact final product properties (66). [Pg.26]

The newly formed y-Mn02 actually coats the surfaces of the particles of the soHd phase the MnSO dissolves in the Hquid phase, along with the majority of the ore impurities. The effective surface area is expanded by the etching action of the sulfuric acid. Following the acid treatment step, the slurry is filtered and the cake is carefiiUy washed and dried at a controlled temperature. [Pg.511]

PyCis usuaHy expressed in percentage, but the % sign is often omitted. Although many additives in the paint formulation are nonvolatile, they are often omitted from this calculation, because they represent a smaH fraction of the volume of a newly formed paint film and, in exterior paints, are often water-soluble materials leached out by rainfaH, and therefore wHl probably not factor into the long-term performance of the paint film. [Pg.543]

Structure of the Cell Wall. The iaterior stmcture of the ceU wall is shown in Figure 6. The interfiber region is the middle lamella (ML). This region, rich in lignin, is amorphous and shows no fibnUar stmcture when examined under the electron microscope. The cell wall is composed of stmcturaHy different layers or lamellae, reflecting the manner in which the cell forms. The newly formed cell contains protoplasm, from which cellulose and the other cell wall polymers are laid down to thicken the cell wall internally. Thus, there is a primary wall (P) and a secondary wall (S). The secondary wall is subdivided into three portions, the S, S2, and layers, which form sequentially toward the lumen. Viewed from the lumen, the cell wall frequendy has a bumpy appearance. This is called the warty layer and is composed of protoplasmic debris. The warty layer and exposed layer are sometimes referred to as the tertiary wad. [Pg.250]

Not only is sucrose yield directly reduced as this reaction proceeds, but more nonsucrose components are formed. If 1% of the sucrose in a juice is hydroly2ed, it turns into 1% nonsucrose components and the resultant loss to extraction is 2.5% (1% directly + 1.5% reduced crystallisation yield). Each metric ton of the newly formed nonsucrose material salts 1.5 t of sucrose into molasses. The reaction has commercial significance at levels of only a few hundred parts per million. [Pg.27]

Just under the bark of a tree is a thin layer of cells, not visible to the naked eye, called the cambium. Here, cells divide and eventually differentiate to form bark tissue outside of the cambium and wood or xylem tissue iaside of the cambium. This newly formed wood on the iaside contains many living cells and conducts sap upward ia the tree, and hence, is called sapwood. Eventually, the inner sapwood cells become iaactive and are transformed iato heartwood. This transformation is often accompanied by the formation of extractives that darken the wood, make it less porous, and sometimes provide more resistance to decay. [Pg.320]

The NOBS system undergoes an additional reaction that forms a diacyl peroxide as a result of the nucleophilic attack of the peracid anion on the NOBS precursor as shown in equation 21. This undesirable side reaction can be minimized by the use of an excess molar quantity of hydrogen peroxide (91,96) or by the use of shorter dialkyl chain acid derivatives. However, the use of these acid derivatives also appears to result in less efficient bleaching. The dependence of the acid group on the side product formation is apparentiy the result of the proximity of the newly formed peracid to unreacted NOBS in the micellar environment (91). A variety of other peracid precursor stmctures can be found (97—118). [Pg.147]

Figure 1 shows the mechanistic picture developed by C. M. Starks (1,2) for Hquid—Hquid PTC in a graphical form. The catalyst cation extracts the more hpholilic anion Y from the aqueous to the nonpolar organic phase where it is present in the form of a poorly solvated ion pair Y ]. This then reacts rapidly with RX, and the newly formed ion pair X ] returns to the aqueous phase for another exchange process X — Y . In practice most catalyst cations used are rather lipophilic and do not extract strongly into the aqueous phase so that the anions are exchanged at the phase boundary. [Pg.186]

Under favorable conditions the thermite produces temperatures of about 2200°C, high enough to turn the newly formed metallic iron into a white-hot Liquid that acts as a heat reservoir to prolong and spread the heat or igniting action. [Pg.401]

Contact Dryers. Coatings on webs as well as sheets of newly formed paper can be dried by contacting the web around the surface of a heated dmm. Thus conduction is used to transfer the heat. Dmms can also be used to rapidly cool warm extmded films, to increase the viscosity, and soHdify the film. [Pg.315]

The soft-nucleophile-soft-electrophile combination is also associated with a late transition state, in which the strength of the newly forming bond contributes significantly to the stability of the transition state. The hard-nucleophile-hffld-elechophile combination inqilies an early transition state with electrostatic attraction being more important than bond formation. The reaction pathway is chosen early on the reaction coordinate and primarily on the basis of charge distributiotL... [Pg.293]

The stereochemical features of the Claisen rearrangement are very similar to those described for the Cope rearrangement, and reliable stereochemical predictions can be made on the basis of the preference for a chairlike transition state. The major product has the -configuration at the newly formed double bond because of the preference for placing the larger substituent in the pseudoequatorial position in the transition state. ... [Pg.633]


See other pages where Newly formed is mentioned: [Pg.85]    [Pg.86]    [Pg.3]    [Pg.17]    [Pg.31]    [Pg.19]    [Pg.20]    [Pg.24]    [Pg.32]    [Pg.288]    [Pg.89]    [Pg.451]    [Pg.222]    [Pg.234]    [Pg.303]    [Pg.14]    [Pg.445]    [Pg.468]    [Pg.152]    [Pg.154]    [Pg.252]    [Pg.542]    [Pg.386]    [Pg.562]    [Pg.41]    [Pg.41]    [Pg.346]    [Pg.131]    [Pg.654]    [Pg.464]   
See also in sourсe #XX -- [ Pg.2 ]

See also in sourсe #XX -- [ Pg.2 ]




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