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61.
Manoel Raimundo dos Santos Junior Elinia Castro Costa Caio Campos Ferreira Lucas Pinto Bernar Marcilene Paiva da Silva Andria de Andrade Mncio Marcelo Costa Santos Sílvio Alex Pereira da Mota Douglas Alberto Rocha de Castro Sergio Duvoisin Junior Luiz Eduardo Pizarro Borges Marilena Emmi Araújo Nlio Teixeira Machado 《Molecules (Basel, Switzerland)》2022,27(7)
In this work, the deoxygenation of organic liquid products (OLP) obtained through the thermal catalytic cracking of palm oil at 450 °C, 1.0 atmosphere, with 10% (wt.) Na2CO3 as a catalyst, in multistage countercurrent absorber columns using supercritical carbon dioxide (SC-CO2) as a solvent, with an Aspen-HYSYS process simulator, was systematically investigated. In a previous study, the thermodynamic data basis and EOS modeling necessary to simulate the deoxygenation of OLP was presented. This work addresses a new flowsheet, consisting of 03 absorber columns, 10 expansions valves, 10 flash drums, 08 heat exchanges, 01 pressure pump, and 02 make-ups of CO2, aiming to improve the deacidification of OLP. The simulation was performed at 333 K, 140 bar, and (S/F) = 17; 350 K, 140 bar, and (S/F) = 38; 333 K, 140 bar, and (S/F) = 25. The simulation shows that 81.49% of OLP could be recovered and that the concentrations of hydrocarbons in the extracts of absorber-01 and absorber-02 were 96.95 and 92.78% (wt.) on a solvent-free basis, while the bottom stream of absorber-03 was enriched in oxygenated compounds with concentrations of up to 32.66% (wt.) on a solvent-free basis, showing that the organic liquid products (OLP) were deacidified and SC-CO2 was able to deacidify the OLP and obtain fractions with lower olefin contents. The best deacidifying condition was obtained at 333 K, 140 bar, and (S/F) = 17. 相似文献
62.
A method for the determination of cross sections for gas-phase protein ions, based on the energy loss of ions as they pass through a collision gas, is described. A simple model relates the energy loss to the number of collisions and hence the cross section. Results from a Monte Carlo model that support the validity of this approach are described. Experimental cross sections are reported for motilin, ubiquitin, cytochrome c, myoglobm, and bovine serum albumin. Cross sections range from approximately 800 Å2 for motilin to approximately 14,000 Å2 for bovine serum albumin and generally increase with the number of charges on the ion. Cytochrome c ions from aqueous solution show somewhat smaller cross sections than ions formed from solutions of higher organic content, suggesting that the gas-phase ions may retain some memory of their solution conformation. 相似文献
63.
We present an equilibrium theory of diblock copolymers in which one of the blocks is crystallizable and the other is amorphous. The material is assumed to order in a lamellar structure of alternating semi-crystalline and amorphous layers with the chemical bonds which connect the copolymer blocks lying in the interfacial regions between the layers. The amorphous blocks are modelled as flexible chains, each with one end (the joint) anchored in an interface. Their contribution to the free energy is calculated via the self-consistent solution of the modified diffusion equations. The crystalline regions are modelled as folded chains, also with one end in an interfacial region (bonded to the corresponding end of an amorphous block). We find that the calculated amorphous block-free energies can be expressed as a single universal function depending on the total degree of polymerization of the amorphous block, its stretching, and a parameter proportional to the thickness of the interface. We have fitted an analytical form to this function, which can be used for any amorphous block, and we have combined it with our model of the crystallizable block to obtain scaling laws describing the equilibrium morphology. 相似文献
64.
Alyssa B. Sanders Jacob T. Zangaro Nakoa K. Webber Ryan P. Calhoun Elizabeth A. Richards Samuel L. Ricci Hannah M. Work Daniel D. Yang Kaitlyn R. Casey Joseph C. Iovine Gabriela Baker Taylor V. Douglas Sierra B. Dutko Thomas J. Fasano Sarah A. Lofland Ashley A. Rajan Mihaela A. Vasile Benjamin R. Carone Nathaniel V. Nucci 《Molecules (Basel, Switzerland)》2022,27(5)
Despite considerable advances in recent years, challenges in delivery and storage of biological drugs persist and may delay or prohibit their clinical application. Though nanoparticle-based approaches for small molecule drug encapsulation are mature, encapsulation of proteins remains problematic due to destabilization of the protein. Reverse micelles composed of decylmonoacyl glycerol (10MAG) and lauryldimethylamino-N-oxide (LDAO) in low-viscosity alkanes have been shown to preserve the structure and stability of a wide range of biological macromolecules. Here, we present a first step on developing this system as a future platform for storage and delivery of biological drugs by replacing the non-biocompatible alkane solvent with solvents currently used in small molecule delivery systems. Using a novel screening approach, we performed a comprehensive evaluation of the 10MAG/LDAO system using two preparation methods across seven biocompatible solvents with analysis of toxicity and encapsulation efficiency for each solvent. By using an inexpensive hydrophilic small molecule to test a wide range of conditions, we identify optimal solvent properties for further development. We validate the predictions from this screen with preliminary protein encapsulation tests. The insight provided lays the foundation for further development of this system toward long-term room-temperature storage of biologics or toward water-in-oil-in-water biologic delivery systems. 相似文献
65.
Using the phenomenological relativistic harmonic model (RHM) for quarks, we have obtained the masses of S wave charmonium and bottomonium states. The full Hamiltonian used in the investigation has Lorentz scalar plus vector confinement potential, along with the confined one gluon exchange potential (COGEP). A good agreement with the experimental masses for the ground and the radially excited states is obtained both for the triplet and singlet S wave mesons. The decay properties of the ground state charmonium and bottomonium are investigated. 相似文献
66.
Mast TD 《The Journal of the Acoustical Society of America》2007,121(6):3311-3322
A general approach is presented for determining the acoustic fields of rectangularly symmetric, baffled, time-harmonic sources under the Fresnel approximation. This approach is applicable to a variety of separable source configurations, including uniform, exponential, Gaussian, sinusoidal, and error function surface velocity distributions, with and without focusing in either surface dimension. In each case, the radiated field is given by a formula similar to that for a uniform rectangular source, except for additional scaling of wave number and azimuthal distance parameters. The expressions presented are generalized to three different Fresnel approximations that correspond, respectively, to diffracted plane waves, diffracted spherical waves, or diffracted cylindrical waves. Numerical results, for several source geometries relevant to ultrasonic applications, show that these expressions accurately depict the radiated pressure fields, except for points very near the radiating aperture. Highest accuracy near the source is obtained by choice of the Fresnel approximation most suited to the source geometry, while the highest accuracy far from the source is obtained by the approximation corresponding to diffracted spherical waves. The methods are suitable for volumetric computations of acoustic fields including focusing, apodization, and attenuation effects. 相似文献
67.
68.
Wm. Douglas Withers 《Constructive Approximation》1989,5(1):151-170
The problem of fitting a given function in theL q norm with a function generated by an iterated function system can be rapidly solved by applying Newton's method on the parameter space of the iterated function system. The key to this is a method for calculating the derivatives of a potential function with respect to the parameters. 相似文献
69.
Douglas S. Stones 《Journal of Combinatorial Theory, Series A》2010,117(2):204-215
A k×n Latin rectangle on the symbols {1,2,…,n} is called reduced if the first row is (1,2,…,n) and the first column is T(1,2,…,k). Let Rk,n be the number of reduced k×n Latin rectangles and m=⌊n/2⌋. We prove several results giving divisors of Rk,n. For example, (k−1)! divides Rk,n when k?m and m! divides Rk,n when m<k?n. We establish a recurrence which determines the congruence class of for a range of different t. We use this to show that Rk,n≡((−1)k−1(k−1)!)n−1. In particular, this means that if n is prime, then Rk,n≡1 for 1?k?n and if n is composite then if and only if k is larger than the greatest prime divisor of n. 相似文献
70.
Morton Kaplan David J. Moses Dag Ø. Eriksen Mehmet Kildir Douglas R. G. Logan Michael S. Zisman Richard J. McDonald 《Zeitschrift für Physik A Hadrons and Nuclei》1983,313(1-2):31-37
Inclusive4He and4H energy spectra and heavy fragment coincidence correlations have been measured for reactions of 7.31 MeV/u238U with238U and?197Au targets. The H/He production cross sections are in the range 15–26 mb, and their emission spectra are very similar for the two systems. The observed strong kinematic shifts with angle are reproduced in shape and magnitude by Monte Carlo simulations of particle evaporation from projectile-like and target-like fragments, indicating competition between charged particle emission and sequential fission. No evidence is found for high energy charged particle emission associated with ultra-highZ composite systems. Heavy fragment measurements indicate an abundance of quasielastic and deeply inelastic reaction fragments, as well as sequential fission of target and projectile nuclei. For238U nuclei, the fission occurs predominantly in an asymmetric mode, reminiscent of fission at low excitation energy. For238+238U reactions in the vicinity of the grazing angle, the frequency of single sequential fission (with survival of the partner fragment) is twice as large as double sequential fission in which both the target and projectile undergo fission. In238U+197Au reactions, the survival probability of the heavy fragments is even greater. The surprisingly high survival probabilities of high-Z fragments imply a preponderance of very soft collisions in these very-heavy-ion reactions, at least at energies not very far over the Coulomb barrier. 相似文献