The use of experimental design for the study of the corrosion of bronze pretreated with AMT in artificial rainwater

Copper and copper alloys (bronze and brass) are usually employed in the manufacturing of cultural objects. When these alloys are exposed to the atmosphere, damaging corrosion products may form on their surfaces. Corrosion inhibitors are used to minimize the corrosion processes. However, the conditions that obtain the best anticorrosive performance of these inhibitors require the control of several chemical and operational parameters, which are, in practice, often chosen empirically. An experimental design was employed to determine the best values with respect to the concentration of 2-amino-5-mercapto-1,3,4-thiadiazole (AMT), the ethanol content and the immersion time of bronze in the AMT solution to achieve the most protective films on the bronze surface. Electrochemical impedance spectroscopy assays of bronze samples with and without previous immersion in the inhibitor solution and exposed to artificial rainwater were performed at the open circuit potential. The parameters and the influence of their interactions on the inhibitory effect of the film formed on the bronze surface were shown to be statistically significant. The conditions for achieving the most protective films were 0.060 M AMT, 90% v/v EtOH, and 90 min of immersion.     

Polynomial evaluation over finite fields: new algorithms and complexity bounds

An efficient evaluation method is described for polynomials in finite fields. Its complexity is shown to be lower than that of standard techniques, when the degree of the polynomial is large enough compared to the field characteristic. Specifically, if n is the degree of the polynomiaI, the asymptotic complexity is shown to be ${O(\sqrt{n})}$ , versus O(n) of classical algorithms. Applications to the syndrome computation in the decoding of Reed-Solomon codes are highlighted.     

Explicit Space–Time Codes Achieving the Diversity–Multiplexing Gain Tradeoff

A recent result of Zheng and Tse states that over a quasi-static channel, there exists a fundamental tradeoff, referred to as the diversity-multiplexing gain (D-MG) tradeoff, between the spatial multiplexing gain and the diversity gain that can be simultaneously achieved by a space-time (ST) code. This tradeoff is precisely known in the case of independent and identically distributed (i.i.d.) Rayleigh fading, for Tgesn_t+n_r-1 where T is the number of time slots over which coding takes place and n_t,n_r are the number of transmit and receive antennas, respectively. For Tt+n_r-1, only upper and lower bounds on the D-MG tradeoff are available. In this paper, we present a complete solution to the problem of explicitly constructing D-MG optimal ST codes, i.e., codes that achieve the D-MG tradeoff for any number of receive antennas. We do this by showing that for the square minimum-delay case when T=n_t=n, cyclic-division-algebra (CDA)-based ST codes having the nonvanishing determinant property are D-MG optimal. While constructions of such codes were previously known for restricted values of n, we provide here a construction for such codes that is valid for all n. For the rectangular, T>n_t case, we present two general techniques for building D-MG-optimal rectangular ST codes from their square counterparts. A byproduct of our results establishes that the D-MG tradeoff for all Tgesn_t is the same as that previously known to hold for Tgesn_t+n _r-1     

Evaluation of titanium dioxide and cerium oxide as anodes for the electrooxidation of toluene: A theoretical approach of the electrode process

Cerium oxide and titanium dioxide were prepared by thermal decomposition of the precursor salts and thermal treatment of titanium plates. In aqueous medium, the metal oxides show a well-defined electrochemical reaction; a solid state redox process takes place in the cathodic range of potentials and only water discharge reaction occurs in the anodic region. At the experimental conditions, the prepared materials were not totally active for the electrooxidation of toluene. The theoretical modeling suggests that the lack of activity is due to the weak interaction between toluene and the metal oxide surface.     

Glutamine and vitamin E in the treatment of hepatic veno-occlusive disease following high-dose chemotherapy

PURPOSE: To analyze the nonfatal adverse events (AE) associated with a first episode of status epilepticus (SE). METHODS: We performed a population-based retrospective cohort study to determine the morbidity of SE. Participants included 184 residents of Rochester, Minnesota who experienced nonfebrile SE between 1965 and 1984. RESULTS: The etiology of SE was acute symptomatic in 100 patients and unprovoked in 84 patients. The most common seizure-types were continuous partial (n=56, 30%), generalized convulsive (n=52, 28%), and generalized with focal features (n=32, 17%). Morbidity related to SE was noted in 5 of the 146 patients (3.4%) surviving 30 days. The AE included hemiparesis (n=3), encephalopathy (n=2), mental retardation (n=1), and aphasia (n=1). All patients with morbidity had an acute symptomatic (n=4) or remote symptomatic (n=1) etiology. Thirty-four patients (18.5%) had a second episode of SE. CONCLUSIONS: Based on this retrospective study, significant morbidity related to SE is uncommon and is associated with the underlying etiology.     

Coproduction of liquid transportation fuels and C6_C8 aromatics from biomass and natural gas

The coproduction of liquid transportation fuels and C₆?C₈ aromatics from the thermochemical conversion of biomass and natural gas (BGTL+C₆_C₈) is investigated in this article. An optimization‐based process synthesis framework incorporating multiple synthesis gas conversion technologies, such as Fischer–Tropsch synthesis or methanol conversion, is described. Production of aromatics can proceed through several technologies, such as naphtha reforming and aromatization of hydrocarbons via a metal‐promoted H‐ZSM‐5 catalyst. This is the first article in the literature to incorporate an aromatics complex for the coproduction of liquid fuels and C₆?C₈ petrochemicals within a rigorous process synthesis and deterministic global optimization framework. The optimal process topologies across several case studies are discussed and the results indicate that the coproduction of aromatics with liquid fuels can significantly increase the profitability of these refineries. © 2015 American Institute of Chemical Engineers AIChE J, 2015 2014 American Institute of Chemical Engineers AIChE J, 61: 831–856, 2015     

A simple,straightforward correlative live‐cell‐imaging‐structured‐illumination‐microscopy approach for studying organelle dynamics

Most cellular organelles are highly dynamic and continuously undergo membrane fission and fusion to mediate their function. Documenting organelle dynamics under physiological conditions, therefore, requires high temporal resolution of the recording system. Concurrently, these structures are relatively small and determining their substructural organization is often impossible using conventional microscopy. Structured Illumination Microscopy (SIM) is a super resolution technique providing a two‐fold increase in resolution. Importantly, SIM is versatile because it allows the use of any fluorescent dye or protein and, hence, is highly applicable for cell biology. However, similar to other SR techniques, the applicability of SIM to high‐speed live cell imaging is limited. Here we present an easy, straightforward methodology for coupling of high‐speed live cell recordings, using spinning disk (SD) microscopy, with SIM. Using this simple methodology, we are able to track individual mitochondrial membrane fission and fusion events in real time and to determine the network connectivity and substructural organization of the membrane at high resolution. Applying this methodology to other cellular organelles such as, ER, golgi, and cilia will no doubt contribute to our understanding of membrane dynamics in cells. Microsc. Res. Tech. 78:777–783, 2015. © 2015 Wiley Periodicals, Inc.     

AN ALGORITHM FOR A PERIOD SEARCH IN A SPARSELY COVERED TIME SERIES AT A FIXED PHASE

Abstract. Researchers are sometimes faced with a set of observations that constitute a sparse coverage of a time series, suspected to be periodic. The period is unknown, but one can identify in the observed data a few points that are presumed to occur at the same phase, in different cycles of the unknown periodicity. We propose an algorithm that finds all periods which are compatible with such observed data, and suggest how to assess their statistical significance. The algorithm also provides stringent limits on the epochs of the fixed phase. We give three examples, from the field of astronomy, for application of our new algorithm. In the first one the algorithm reveals, on the basis of very few photometric observations, a highly significant period in the light curve of the recent classical Nova Herculis 1991. In the second example, in the series of arrival times of neutrinos from the supernova SN1987A, our algorithm yields a definite negative result. It proves that no significant exact periodicity is present in the data. In the third application, the algorithm provides new constraints on the epoch of one of the minima in the light curve of the stellar binary system 44i Bootis. We compare the method with other period search techniques, pointing out a few of its advantages, as well as some of its weaknesses.