From "Sirups" to Biocarbons: A 30 Year Research Cooperation for Better Biomass Utilization with Michael J. Antal, Jr

The results of a 30 year U.S.-Hungarian research cooperation are surveyed. The head of the cooperating U.S. laboratory, Michael J. Antal, Jr., died on Oct 21, 2015. He was a leading person in biomass research. The collaboration started with pyrolysis studies. In this phase of the work, the aim was to clarify the factors that enhance the formation of the valuable volatile products ("sirups"). For this purpose, the kinetics and mechanism of the biomass pyrolysis were studied with a particular emphasis on the behavior of the cellulose component. Later, the interest of the cooperation gradually shifted to the solid products of the pyrolysis: chars, charcoals, and biocarbons. Hence, the formation, properties, and uses of these products were studied. The present paper illustrates the 3 decades of the common work by selected results. Such examples are shown that (i) are thought to be useful in the planning of future studies on pyrolysis and combustion of biomass materials (ii) and/or may help in the interpretation of the existing literature data. The presented results include the choice of the proper experimental conditions, the evaluation of experiments with linear and nonlinear temperature programs by the method of least squares, the assessment of complex mechanism schemes by a suitable series of experiments, and the kinetic modeling of the combustion of inhomogeneous chars in the kinetic regime

Origin of the ESR spectrum in the Prussian Blue analogue RbMn[Fe(CN)6]*H2O

We present an ESR study at excitation frequencies of 9.4 GHz and 222.4 GHz of powders and single crystals of a Prussian Blue analogue (PBA), RbMn[Fe(CN)6]*H2O in which Fe and Mn undergoes a charge transfer transition between 175 and 300 K. The ESR of PBA powders, also reported by Pregelj et al. (JMMM, 316, E680 (2007)) is assigned to cubic magnetic clusters of Mn2+ ions surrounding Fe(CN)6 vacancies. The clusters are well isolated from the bulk and are superparamagnetic below 50 K. In single crystals various defects with lower symmetry are also observed. Spin-lattice relaxation broadens the bulk ESR beyond observability. This strong spin relaxation is unexpected above the charge transfer transition and is attributed to a mixing of the Mn3+ - Fe2+ state into the prevalent Mn2+ - Fe3+ state.Comment: 5 pages, 4 figures, submitted to PR

Formation of Liesegang patterns: Simulations using a kinetic Ising model

A kinetic Ising model description of Liesegang phenomena is studied using Monte Carlo simulations. The model takes into account thermal fluctuations, contains noise in the chemical reactions, and its control parameters are experimentally accessible. We find that noisy, irregular precipitation takes place in dimension d=2 while, depending on the values of the control parameters, either irregular patterns or precipitation bands satisfying the regular spacing law emerge in d=3.Comment: 7 pages, 8 ps figures, RevTe

AdS_4/CFT_3 Construction from Collective Fields

We pursue the construction of higher-spin theory in AdS_4 from CFT_3 of the O(N) vector model in terms of canonical collective fields. In null plane quantization an exact map is established between the two spaces. The coordinates of the AdS_4 space-time are generated from the collective coordinates of the bi-local field. This, in the light cone gauge, provides an exact one to one reconstruction of bulk AdS_4 space-time and higher-spin fields.Comment: 17 pages, no figures; v2: references added; v3: minor change

Derivation of the Matalon-Packter law for Liesegang patterns

Theoretical models of the Liesegang phenomena are studied and simple expressions for the spacing coefficients characterizing the patterns are derived. The emphasis is on displaying the explicit dependences on the concentrations of the inner- and the outer-electrolytes. Competing theories (ion-product supersaturation, nucleation and droplet growth, induced sol- coagulation) are treated with the aim of finding the distinguishing features of the theories. The predictions are compared with experiments and the results suggest that the induced sol-coagulation theory is the best candidate for describing the experimental observations embodied in the Matalon-Packter law.Comment: 9 pages, 7 figures, RevTe

Probability distribution of magnetization in the one-dimensional Ising model: Effects of boundary conditions

Finite-size scaling functions are investigated both for the mean-square magnetization fluctuations and for the probability distribution of the magnetization in the one-dimensional Ising model. The scaling functions are evaluated in the limit of the temperature going to zero (T -> 0), the size of the system going to infinity (N -> oo) while N[1-tanh(J/k_BT)] is kept finite (J being the nearest neighbor coupling). Exact calculations using various boundary conditions (periodic, antiperiodic, free, block) demonstrate explicitly how the scaling functions depend on the boundary conditions. We also show that the block (small part of a large system) magnetization distribution results are identical to those obtained for free boundary conditions.Comment: 8 pages, 5 figure

Matrix Model Maps and Reconstruction of AdS SUGRA Interactions

We consider the question of reconstructing (cubic) SUGRA interactions in AdS/CFT. The method we introduce is based on the matrix model maps (MMP) which were previously successfully employed at the linearized level. The strategy is to start with the map for 1/2 BPS configurations which is exactly known (to all orders) in the hamiltonian framework. We then use the extension of the matrix model map with the corresponding Ward identities to completely specify the interaction. A central point in this construction is the non-vanishing of off-shell interactions (even for highest-weight states).Comment: 28 page

Energy rebound due to re-spending: A growing concern

Energy conservation is widely accepted as an important strategy to combat climate change. It can, nevertheless, stimulate new energy uses that partly offset the original savings. This is known as rebound. One particular rebound mechanism is re-spending of money savings associated with energy savings on energy intensive goods or services. We calculate the average magnitude of this "re-spending rebound" for different fuels and countries. We find that emerging economies, neglected in past studies, typically have substantially larger rebounds than OECD countries. The effect is generally stronger for gasoline than for natural gas and electricity. Paradoxically, strengthening financial incentives to conserve energy tends to increase rebound. This is expected to gain importance with climate regulation and peak oil. We discuss the policy implications of our findings