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Proton energy

Ionization energies can be computed to about 0.2 eV rotational barriers to about 0.5 kcal/mol dipole moments to about 0.5 D barriers to inversion to about 2.5 kcal/mol infrared frequencies can be computed with about a 15% error (usuaHy too high) and protonation energies are accurate to about 1 piCunit. [Pg.162]

Figure 2 Cross section versus incident proton energy for the (p, cx) N reaction, with a beam-detector angie of 165°. ... Figure 2 Cross section versus incident proton energy for the (p, cx) N reaction, with a beam-detector angie of 165°. ...
Electrophilic addition of HX to an alkene involves a two-step mechanism, the overall rate being given by the rate of the initial protonation step. Differences in protonation energies are usually explained by considering differences in carbocation stability, but the relief or buildup of strain can also be a factor. One of the following alkenes protonates much more easily than the other. [Pg.105]

In a solution containing such particles, the conditions for equilibrium in all possible proton transfers must be satisfied simultaneously, In terms of these proton energy levels, we may say that this is made possible by the additivity of the J values. In Fig. 38 the values of J for the three proton transfers have been labeled J1, J2, and J3. From the relation J3 = Ji + Ji) we may obtain at once a relation between the values of Kx, and hence between the equilibrium constants K. In the proton transfer labeled Jt the number of solute particles remains unchanged, whereas in J4 and Jt the number of solute particles is increased by unity. [Pg.136]

Principles and Characteristics Particle-induced X-ray emission spectrometry (PIXE) is a high-energy ion beam analysis technique, which is often considered as a complement to XRF. PIXE analysis is typically carried out with a proton beam (proton-induced X-ray emission) and requires nuclear physics facilities such as a Van der Graaff accelerator, or otherwise a small electrostatic particle accelerator. As the highest sensitivity is obtained at rather low proton energies (2-4 MeV), recently, small and relatively inexpensive tandem accelerators have been developed for PIXE applications, which are commercially available. Compact cyclotrons are also often used. [Pg.639]

It is apparent that PIXE exhibits its maximum sensitivity or minimum detection limit (MDL) in the two atomic number regions 20 < Z < 35 and 75 < Z < 85. These are attained at relatively low proton energies, which implies that small accelerators are most suitable for PIXE with the corresponding benefits in reliability and economics. Analysis times are typically a few minutes in duration. The MDL is very strongly influenced by the nature of the sample, especially if there are strong X-rays from the matrix visible in the spectrum or if the sample is strongly insulating. [Pg.99]

Figure 4.18. Minimum detectable concentrations as a function of atomic number and proton energy for thin organic specimens in a typical PIXE arrangement. (Reproduced by permission of Johansson... Figure 4.18. Minimum detectable concentrations as a function of atomic number and proton energy for thin organic specimens in a typical PIXE arrangement. (Reproduced by permission of Johansson...
Dynamic nuclear polarisation (DNP) enhanced 15N CP MAS NMR has been exploited by Mark-Jurkauskas et al.79 in the studies of intermediates of the bacteriorhodopsin photocycle. The data for L intermediate were similar to those found for 13-ds,15-anti retylidene chloride, while those for K intermediate were similar to those of acid blue bacteriorhodopsin in which the Schiff base counterion was neutralised (Table 3). The 15N chemical shifts observed have shown that for bacteriorhodopsin, the Schiff base in K intermediate state loses contact with its counterion and establishes a new one in L intermediate state. The proton energy stored at the beginning in the electrostatic modes has been transformed to torsional modes. The transfer of energy is facilitated by the reduction of bond order alternation in the polyene chain when the counterion interaction is initially broken and is driven by the attraction of the Schiff base to a new counterion. 3D CP MAS experiments of NCOCX, NCACX, CONCA and CAN(CO)CA types have been used in studies of proteorhodopsin.71... [Pg.159]

Dalgarno and Griffing (1958) made a detailed theoretical analysis of the ionization produced by a beam of protons penetrating a gas of H atoms. They find that the W value remains constant at around 36 eV, to within 2.5 eV, for proton energies of 10 KeV and up. However, below about 100 KeV, the near constancy of the W value is also partially due to the fact that the beam is a near equilibrium composition of protons and H atoms because of charge exchange. Therefore, at... [Pg.104]

Using the INDO approximation on fully optimized geometries, the lone pair orbital energy (eN) (of 3-N) in 4-aminoimidazole (179 R = R2 = H) was calculated to be 0.4482 au and the protonation energy (AEp) of the same molecule was calculated to be 374.9 kcal mol-1 (83H1717). [Pg.48]

Because of the lattice damage, the absorptions due to the local modes of vibration are usually broader in implanted materials than, for instance, in plasma diffused samples. For proton energies around 1 MeV, the line-widths are in the range 5-100 cm-1 (as compared with 0.1-5 cm-1 for plasma hydrogenation). [Pg.508]

MeV required in proton-therapy for an effective treatment of deep seated tumors [26]. Fuchs and co-authors have proposed a scaling law [27], allowing the necessary laser parameters to produce proton beams of interest for such applications to be estimated. In their work, best suited to hundreds of fs/some ps duration laser pulses, they use the self-similar fluid model proposed by Mora [28] giving the following estimate for the maximum FWD proton energy ... [Pg.190]

Fig. 10.2. Peak proton energies as a function of target thickness from three different works (see main text). Pictures are extracted from (I) [35], (II) [36], and (III) [43]... Fig. 10.2. Peak proton energies as a function of target thickness from three different works (see main text). Pictures are extracted from (I) [35], (II) [36], and (III) [43]...
Fig. 10.5. Dependence of the FWD and BWD maximum proton energy on target thickness in low contrast and ultra high contrast conditions. The insert shows a typical output of the Thomson parabolas for the same shot on a sub-micrometer target. After protons, carbon ions result in the most intense signals... Fig. 10.5. Dependence of the FWD and BWD maximum proton energy on target thickness in low contrast and ultra high contrast conditions. The insert shows a typical output of the Thomson parabolas for the same shot on a sub-micrometer target. After protons, carbon ions result in the most intense signals...
Fig. 10.6. 2D CALDER simulations for UHC experimental parameters FWD and BWD proton energy distributions (a) and related electron phase space plot (b) at the laser peak... Fig. 10.6. 2D CALDER simulations for UHC experimental parameters FWD and BWD proton energy distributions (a) and related electron phase space plot (b) at the laser peak...
Fig. 10.9. Comparison of experimental data and 2D PIC simulations results for FWD and BWD maximum proton energy as a function of the target thickness (left), and peak proton energy shot-to-shot variation in UHC regime for FWD and BWD emission (right)... Fig. 10.9. Comparison of experimental data and 2D PIC simulations results for FWD and BWD maximum proton energy as a function of the target thickness (left), and peak proton energy shot-to-shot variation in UHC regime for FWD and BWD emission (right)...
Fig. 10.10. Dependence of the maximum proton energy on the laser polarization for a 13 pm mylar target in UHC conditions in the BWD (left) and in the FWD (right) direction, and 2D PIC simulations results for p and s polarization. The dashed line represents Fmax oc p x y/cos(29)2... Fig. 10.10. Dependence of the maximum proton energy on the laser polarization for a 13 pm mylar target in UHC conditions in the BWD (left) and in the FWD (right) direction, and 2D PIC simulations results for p and s polarization. The dashed line represents Fmax oc p x y/cos(29)2...

See other pages where Proton energy is mentioned: [Pg.158]    [Pg.685]    [Pg.685]    [Pg.175]    [Pg.137]    [Pg.137]    [Pg.60]    [Pg.271]    [Pg.225]    [Pg.659]    [Pg.642]    [Pg.129]    [Pg.135]    [Pg.166]    [Pg.359]    [Pg.135]    [Pg.175]    [Pg.187]    [Pg.189]    [Pg.190]    [Pg.190]    [Pg.192]    [Pg.193]    [Pg.193]    [Pg.193]    [Pg.194]    [Pg.197]    [Pg.198]    [Pg.199]    [Pg.200]    [Pg.201]    [Pg.202]    [Pg.203]   
See also in sourсe #XX -- [ Pg.103 ]




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Activation energy for proton exchange

Activation energy proton association effect

Activation energy proton transfer reactions

Adiabatic Proton Transfer Free Energy Relationship (FER)

Density functional theory proton solvation energy

Effects of proton beam energy

Electrolysis, hydrogen from Proton Energy Systems

Electron, proton, and energy transfer

Energy Profile of Proton Transfer to a Hydride Ligand in Solution

Energy Profile of protonation

Energy barrier to proton transfer

Energy clustering, protonated hydrates

Energy of proton transfer

Energy proton transfer reactions

Energy through proton transfer

Energy, protonation

Energy, protonation

Energy-transducing membranes proton transport

Free energy for proton transfer

Free energy of protonation, and

Free energy proton

Gibbs free standard energy proton solvation

High-energy protons

Hydrated protons solvation energy

Measurement of a Neutron Energy Spectrum by Proton Recoil

Nuclear energy protons

Potential energy proton transfer

Potential energy surface Proton tunnelling

Potential energy surface Proton-transfer

Proton Energy Systems

Proton activation energy

Proton beam energy

Proton binding energy

Proton energy profile

Proton exchange membrane fuel cell electrical energy efficiency

Proton free energy levels

Proton separation energy

Proton solvation energy

Proton transfer activation energy

Proton transfer activation free energy

Proton transfer energies

Proton transfer energy barrier

Proton transfer energy profile

Proton transfer free energy

Proton transfer, linear free energy

Proton transfer, linear free energy relationship

Proton transport electrostatic activation energy

Proton tunneling potential energy surface

Proton, energies gradient

Protonated cyclopropane relative energies

Protonation Energies and Basicities of Enamines

Protonation, free energies

Protons energy shells

Protons nuclear binding energy

Relative reaction energy in partial protonation of primary versus tertiary carbon atoms

Repulsive energy between protons

Strain energies proton sponges

The energy-transducing membrane is topologically closed and has a low proton permeability

Theoretical Simulations of Free Energy Relationships in Proton Transfer

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