No abstract

The addition of concurrent cisplatin-based CT to RT significantly improves progression-free and overall survival for high-risk, early-stage patients who undergo radical hysterectomy and pelvic lymphadenectomy for carcinoma of the cervix.

The homogeneous vapor phase cracking of newly formed wood pyrolysis tar was studied at low molar concentrations as a function of temperature (773–1,073 K), at residence times of 0.9–2.2 s. Tar conversions ranged from about 5 to 88%. The tars were generated by low heating rate (0.2 K/s) pyrolysis of ∼2 cm deep beds of sweet gum hardwood, and then rapidly conveyed to an adjacent reactor for controlled thermal treatment. Quantitative yields and kinetics were obtained for tar cracking and resulting products formation. The major tar conversion product was carbon monoxide, which accounted for over two‐thirds of the tar lost at high severities. Corresponding ethylene and methane yields were each about 10% of the converted tar. Coke formation was negligible and weight‐average tar molecular weight declined with increasing tar conversion. A first‐order distributed activation energy model more closely correlated tar conversion kinetics over a wider range of reaction conditions than did a single‐reaction model.

The neutron unbound ground state of (25)O (Z=8, N=17) was observed for the first time in a proton knockout reaction from a (26)F beam. A single resonance was found in the invariant mass spectrum corresponding to a neutron decay energy of 770_+20(-10) keV with a total width of 172(30) keV. The N=16 shell gap was established to be 4.86(13) MeV by the energy difference between the nu1s(1/2) and nu0d(3/2) orbitals. The neutron separation energies for (25)O agree with the calculations of the universal sd shell model interaction. This interaction incorrectly predicts an (26)O ground state that is bound to two-neutron decay by 1 MeV, leading to a discrepancy between the theoretical calculations and experiment as to the particle stability of (26)O. The observed decay width was found to be on the order of a factor of 2 larger than the calculated single-particle width using a Woods-Saxon potential.

Ind. Eng. Chem. Process Des. Dev. 1982, 21, 457-465 457 days this operating procedure has wide perspectives in industrial adsorption separation. If a complete mathematical model whose parameter values are obtained by a few experimental runs is available, it is possible to explore the whole range of operating conditions without restrictions and therefore to obtain a proper design. Acknowledgment from SISAS S.p.A. Nomenclature a = external particle surface/particle volume, l/cm c, = concentration in external liquid phase, mol/L ci = concentration in liquid phase into macroporosity (internal Deff = effective diffusion coefficient (eq E), cm2/s DL = axial diffusion coefficient, cm2/s fq = mathematical expression of adsorption isotherm k , = film mass transfer coefficient, cm/s ki = intraparticle mass transfer coefficient (into macroporosity), cm/s K = equilibrium constant of adsorption, L/mol K, K* = pseudolinear equilibrium constant of adsorption, defined by eq 10, 12, L/mol KL = global mass transfer coefficient, cm/s L = length of the column, cm N.C. = number of the components Pe = Peclet number (= 2uRp/D~.e,) R, = radius of spherical particle equivalent to the solid pellet, t = time, s tR = retention time of a component t (= L/u), s u = fluid velocity, cm/s u = interstitial fluid velocity, cm/s u j = effective velocity of component j (eq ll), cm/s z = axial length coordinate, cm Greek Symbols a, p = coefficients introduced in eq 21 The authors gratefully acknowledge financial support phase), mol/L cm L i t e r a t u r e Cited Broughton, D. B.; Neuzll, R. W.; Pharis, J. M.; Brearley, C. S. Chem. Eng. Prog. 1970. 66, 70. Butt, J. B. "Reaction Kinetics and Reactor Design"; Rentice-Hall: Engelwood Cllffs, NJ, 1960 p 274. De Rosset, A. J.; NeuzU, R. W.; Korous, D. J. Ind. Eng . Chem . Process Des. Dev. 1978, 15, 261. Garg, D. R.; Ruthven, D. M. Chem. Eng. Sci. 1974. 29, 571. Keulemans, A. I. M. "Qas Chromatography", 2nd ed.; Relnhold New York, Liapis, A. I.; Rlppin, D. W. T. Chem. €ng. Sci. 1977, 33, 593. Morbldelll. M.; Servida, A.; Can& S. submltted to Chem. Eng. Comp. 1982. Santacesarla, E.; MorbMelll, M.; Denise, P.; Mercenari, M.; C a d , S. Ind. Eng. Chem. Process Des. Dev. 1982a. Part 1 of thls series, published in this issue. Santacesaria, E.; Morbldelli, M.; Servlda, A.; Storti, G.; Car& S. Ind. Eng. Chem. Process Des. Dev. 1882b. Part 2 of this series, publlshed in thls Issue. Seko, M.; Mlyake, T.; Inada, K.

No abstract

Yields, compositions, and selected elemental analyses have been determined for products from the pyrolysis of pulverized Montana lignite in a batch reactor. Heating rate, peak temperature, and residence time at the peak temperature were independently varied in the ranges 100-104 °C/s, 150-1100 °C, and 0-10 s. Yields of all volatile products increased monotonically with temperature at 1000 °C/s and 1 atm of helium, approaching the following asymptotes at 1000 °C: 16.5% water (including 6.8% moisture), 9.5% carbon dioxide, 9.4% carbon monoxide, 5.4% tar, 1.3% methane, 0.6% ethylene, 0.5% hydrogen, and 0.9% ethane, propylene, propane, benzene, plus trace hydrocarbons. Pyrolysis at 1000 °C volatilized about 70% of the sulfur and 25% of the nitrogen. The kinetics of production of major volatile species was modeled with one to three independent parallel first-order reactions. The frequency distribution of the derived activation energies agrees well with a Gaussian distribution previously obtained from weight loss data for the same lignite.

The best examples of halo nuclei, exotic systems with a diffuse nuclear cloud surrounding a tightlybound core, are found in the light, neutron-rich region, where the halo neutrons experience only weak binding and a weak, or no, potential barrier. Modern direct reaction measurement techniques provide powerful probes of the structure of exotic nuclei. Despite more than four decades of these studies on the benchmark one-neutron halo nucleus 11 Be, the spectroscopic factors for the two bound states remain poorly constrained. In the present work, the 10 Be(d,p) reaction has been used in inverse kinematics at four beam energies to study the structure of 11 Be. The spectroscopic factors extracted using the adiabatic model, were found to be consistent across the four measurements, and were largely insensitive to the optical potential used. The extracted spectroscopic factor for a neutron in a n j = 2s 1/2 state coupled to the ground state of 10 Be is 0.71(5). For the first excited state at 0.32 MeV, a spectroscopic factor of 0.62(4) is found for the halo neutron in a 1p 1/2 state. Nuclear halos are a phenomenon associated with certain weakly-bound nuclei, in which a tail of dilute nuclear matter is distributed around a tightly bound core [1][2][3]. This effect is only possible for bound states with no strong Coulomb or centrifugal barrier, and which lie close to a particle-emission threshold. Though excited-state halos exist, the number of well-studied halo states is predominantly limited to a handful of light, weakly-bound nuclei which exhibit the phenomenon in their ground state.The neutron-rich nucleus 11 Be is a brilliant example of this phenomenon, with halo structures in both of its bound states, and light enough to be modeled with an ab initio approach. It is well documented that the 1/2 + ground state and 1/2 − first excited state in 11 Be are inverted with respect to level ordering predicted from a naïve shell model. There has been considerable theoretical effort toward reproducing this level inversion in a systematic manner, while maintaining the standard ordering in the nearby nuclide 13 C, where the 1/2 + state lies over 3 MeV above the 1/2 − ground state. A Variational Shell Model approach [4] and models which vary the singleparticle energies via vibrational [5] and rotational [6] core couplings reproduce this level inversion in a systematic manner. Common to the success of these models is the inclusion of core excitation. Ab initio No-Core Shell Model calculations [7] have been unable to reproduce this level inversion though a significant drop in the energy of the 1/2 + state in 11 Be is reported with increasing model space. In all of these models, the wave functions for the 11 Be halo states show a considerable overlap with a valence neutron coupled to an excited 10 Be(2 + ) core, in addition to the naïve n⊗ 10 Be(0 + gs ) component. Despite decades of study, the extent of this mixing is not well understood, with both structure calculations and the interpretation of experimental results ranging from a few...