Comparing Nontriviality for E and EXP

A set A is nontrivial for the linear-exponential-time class E=DTIME(2 ^lin ) if for any k≥1 there is a set B _k ∈E such that B _k is (p-m-)reducible to A and B_k ? DTIME(2^k·n)B_{k} \not\in \mathrm{DTIME}(2^{k\cdot n}). I.e., intuitively, A is nontrivial for E if there are arbitrarily complex sets in E which can be reduced to A. Similarly, a set A is nontrivial for the polynomial-exponential-time class EXP=DTIME(2 ^poly ) if for any k≥1 there is a set [^(B)]_k ? EXP\hat{B}_{k} \in \mathrm {EXP} such that [^(B)]_k\hat{B}_{k} is reducible to A and [^(B)]_k ? DTIME(2^nk)\hat{B}_{k} \not\in \mathrm{DTIME}(2^{n^{k}}). We show that these notions are independent, namely, there are sets A ₁ and A ₂ in E such that A ₁ is nontrivial for E but trivial for EXP and A ₂ is nontrivial for EXP but trivial for E. In fact, the latter can be strengthened to show that there is a set A∈E which is weakly EXP-hard in the sense of Lutz (SIAM J. Comput. 24:1170–1189, 11) but E-trivial.     

Breakthrough analysis for CO2 removal by activated hydrotalcite and soda ash

Carbon dioxide sorption rate parameters and sorption capacities on two different regenerable sorbents, namely hydrotalcite and activated trona, were investigated in a fixed bed flow adsorber, in the temperature range of 400–527 °C and 80–152 °C, respectively. Hydrotalcite, which was activated at 550 °C, was shown to give total and breakthrough CO₂ sorption capacities as high as 1.16 and 0.70 mmol/g, respectively, at 452 °C, in the absence of water vapor. In the presence of excess water vapor, the total CO₂ sorption capacity was not affected much, however a decrease in the breakthrough capacity and on the sorption rate constant was observed, especially at lower temperatures. In the presence of water vapor, activated trona was shown to give comparable total and breakthrough CO₂ sorption capacities, at much lower temperatures (T < 100 °C). The deactivation model gave good predictions of the CO₂ breakthrough curves and it was successfully used for the evaluation of the adsorption and the deactivation rate constants.     

A GRAIN MODEL FOR CATALYST TORTUOSITY

A simple model was proposed for the prediction of tortuosity factor of porous solids with mono or bidispersed pore size distributions. Model predictions were presented in graphical form for quick estimation of tortuosity. The experimental tortuosity factors reported in the literature for porous solids of different pore structures and the corresponding predicted values showed good agreement.     

Evaluating the performance of BSBL methodology for EEG source localization on a realistic head model

In this paper, we evaluate the performance of block sparse Bayesian learning (BSBL) method for EEG source localization. By exploiting the internal block structure, the BSBL method solves the ill‐posed inverse problem more efficiently than other methods that do not consider block structure. Simulation experiments were conducted on a realistic head model obtained by segmentation of MRI images of the head. Two definitions of blocks were considered: Brodmann areas and automated anatomical labeling (AAL). The experiments were performed both with and without the presence of noise. Six different noise levels were considered having SNR values from 5 dB to 30 dB with 5dB increment. The evaluation reveals several potential findings—first, BSBL is more likely to produce better source localization than sparse Bayesian learning (SBL), however, this is true up until a limited number of simultaneously active areas only. Experimental results show that for 71‐channel electrodes setup BSBL outperforms SBL for up to three simultaneously active blocks. From four simultaneously active blocks SBL turns out to be marginally better and the difference between them is statistically insignificant. Second, different anatomical block structures such as Brodmann areas or AAL does not seem to produce any significant difference in EEG source localization relying on BSBL. Third, even when the block partitions are not known exactly BSBL ensures better localization than SBL as soon as block structure persists in the signal. © 2017 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 27, 46–56, 2017     

Scrubbing of SO2 with trona solution in a spray drier

Effect of operating variables on the scrubbing efficiency of SO₂ in a spray drier was investigated using trona (Na₂ CO₃ · NaHCO₃ · 2H₂ O) solutions of different compositions. Results indicated that for a Na/S mole ratio of two (stoichiometric ratio) about 80% of the SO₂ was removed. For higher Na/S ratios, SO₂ removal efficiency increased by up to 100%. Increased SO₂ concentration in the feed gas and decreased outlet temperature caused an increase in the overall conversion. At low temperatures and low SO₂ concentration, the reaction takes place mainly between SO₂ and Na₂ CO₃ As the temperature is increased, decomposition of NaHCO₃ to Na₂ CO₃ and sorption reactions take place simultaneously.     

RbfA Is Involved in Two Important Stages of 30S Subunit Assembly: Formation of the Central Pseudoknot and Docking of Helix 44 to the Decoding Center

Ribosome biogenesis is a highly coordinated and complex process that requires numerous assembly factors that ensure prompt and flawless maturation of ribosomal subunits. Despite the increasing amount of data collected, the exact role of most assembly factors and mechanistic details of their operation remain unclear, mainly due to the shortage of high-resolution structural information. Here, using cryo-electron microscopy, we characterized 30S ribosomal particles isolated from an Escherichia coli strain with a deleted gene for the RbfA factor. The cryo-EM maps for pre-30S subunits were divided into six classes corresponding to consecutive assembly intermediates: from the particles with a completely unresolved head domain and unfolded central pseudoknot to almost mature 30S subunits with well-resolved body, platform, and head domains and partially distorted helix 44. The structures of two predominant 30S intermediates belonging to most populated classes obtained at 2.7 Å resolutions indicate that RbfA acts at two distinctive 30S assembly stages: early formation of the central pseudoknot including folding of the head, and positioning of helix 44 in the decoding center at a later stage. Additionally, it was shown that the formation of the central pseudoknot may promote stabilization of the head domain, likely through the RbfA-dependent maturation of the neck helix 28. An update to the model of factor-dependent 30S maturation is proposed, suggesting that RfbA is involved in most of the subunit assembly process.     

Dynamic analysis of adsorption equilibrium and rate parameters of reactants and products in MTBE,ETBE and TAME production

Adsorption equilibrium constants of ethanol, methanol, isobutylene, isoamylenes (2M2B, 2M1B), MTBE and TAME on Amberlyst 15 catalyst were evaluated from the packed bed moment technique. Adsorption equilibrium constants of alcohols were found to be two orders of magnitude greater than the adsorption equilibrium constants of i-olefins and the corresponding tertiary ethers. However, their apparent heat of adsorption values are quite low (-6,7 kJ/mol and ?8.3 kJ/mol for methanol and ethanol, respectively). Among the i-olefins, isobutylene gave the highest adsorption equilibrium constant and the heat of adsorption (-54.2 kJ/mol The adsorption equilibrium constant of 2M2B on a catalyst, which was pretreated with ethanol, was about three times greater than the corresponding value obtained on fresh catalyst. Second moment analysis indicated that diffusion resistance in both macropores and microspheres of the catalyst are equally significant.     

Use of a thiophene-based conducting polymer in microbial biosensing

Immobilization of whole viable Pseudomonas fluorescens cells was achieved on a graphite electrode modified with a thiophene-based conducting polymer. Microbial electrodes were constructed by the entrapment of bacterial cells on conducting copolymer matrix using a dialysis membrane. The biosensor was characterized using glucose as the substrate. As well as analytical characterization, effects of electropolymerization time, pH and temperature on the sensor response were examined. Finally, operational stability was also tested.     

Brain Metabolic Profile after Intranasal vs. Intraperitoneal Clomipramine Treatment in Rats with Ultrasound Model of Depression

Background: Molecular mechanisms of depression remain unclear. The brain metabolome after antidepressant therapy is poorly understood and had not been performed for different routes of drug administration before the present study. Rats were exposed to chronic ultrasound stress and treated with intranasal and intraperitoneal clomipramine. We then analyzed 28 metabolites in the frontal cortex and hippocampus. Methods: Rats’ behavior was identified in such tests: social interaction, sucrose preference, forced swim, and Morris water maze. Metabolic analysis was performed with liquid chromatography. Results: After ultrasound stress pronounced depressive-like behavior, clomipramine had an equally antidepressant effect after intranasal and intraperitoneal administration on behavior. Ultrasound stress contributed to changes of the metabolomic pathways associated with pathophysiology of depression. Clomipramine affected global metabolome in frontal cortex and hippocampus in a different way that depended on the route of administration. Intranasal route was associated with more significant changes of metabolites composition in the frontal cortex compared to the control and ultrasound groups while the intraperitoneal route corresponded with more profound changes in hippocampal metabolome compared to other groups. Since far metabolic processes in the brain can change in many ways depending on different routes of administration, the antidepressant therapy should also be evaluated from this point of view.     

Optical phase retrieval by use of first Born- and Rytov-type approximations

The first Born and Rytov approximations of scattering theory are introduced in their less familiar near-field versions. Two algorithms for phase retrieval based on these approximations are then described. It is shown theoretically and by numerical simulations that, despite the differences in their formulation, the two algorithms deliver fairly similar results when used for optical phase retrieval in the near and intermediate fields. The algorithms are applied to derive explicit solutions to four phase-retrieval problems of practical relevance to quantitative phase-contrast imaging and tomography. An example of successful phase reconstruction by use of the Born-type algorithm with an experimental x-ray image is presented.