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121.
Elia P. Kumar K.R. Pawar S.A. Kumar P.V. Hsiao-Feng Lu 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2006,52(9):3869-3884
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 Tgesnt+nr-1 where T is the number of time slots over which coding takes place and nt,nr are the number of transmit and receive antennas, respectively. For Tt+nr-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=nt=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>nt 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 Tgesnt is the same as that previously known to hold for Tgesnt+n r-1 相似文献
122.
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. 相似文献
123.
AP Goringe S Brown U O''Callaghan J Rees S Jebb M Elia CH Poynton 《Canadian Metallurgical Quarterly》1998,21(8):829-832
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. 相似文献
124.
Coproduction of liquid transportation fuels and C6_C8 aromatics from biomass and natural gas
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Alexander M. Niziolek Onur Onel Josephine A. Elia Richard C. Baliban Christodoulos A. Floudas 《American Institute of Chemical Engineers》2015,61(3):831-856
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 相似文献
125.
A simple,straightforward correlative live‐cell‐imaging‐structured‐illumination‐microscopy approach for studying organelle dynamics
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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. 相似文献
126.
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. 相似文献
127.
R Valentino S Savastano AP Tommaselli MT Scarpitta M Dorato M Gigante E Calvanese M Carlino G Lombardi 《Canadian Metallurgical Quarterly》1997,20(11):690-694
A normal gonadal maturation with normal fertility are some of the major goals of long-term replacement therapy in adult males with Congenital Adrenal Hyperplasia (CAH). We describe here two young men, G.O. (case A, 23 years old) and S.S.(case B, 24 years old), both with a well defined diagnosis of CAH due to 21-hydroxylase deficiency classic homozygote form (21-CAH). In case A the diagnosis of the 21-CAH classic virilizing form was made at 3 years of age. The patient has undergone glucocorticoid therapy and is now 170 cm tall; all his hormonal findings are within the normal range. The semen analysis has shown a good fertility potential, with a slight modification when the patient decided to discontinue the therapy. In case B the diagnosis of the 21-CAH salt wasting form was performed at 9 days of age. The patient was initially treated with i.v. normal saline solution and a daily i.m. injection of hydrocortisone and, subsequently, with mineral and glucocorticoid replacement therapy po. A satisfactory adult stature (165 cm) was attained. The patient is still on therapy, with a good hormonal profile. The semen analysis has shown an apparently normal fertility. In conclusion, our experience in adult males with 21-CAH, who have been administered prompt and adequate replacement therapy, shows that these patients can attain normal quality of life, satisfactory growth and development, normal sexual maturation and activity, and adequate sperm fertilizing ability, thereby supporting the usefulness of continuing this therapy during adult age. 相似文献
128.
We construct cooperative diversity coding schemes that mitigate the effects of symbol asynchronicity among network users.
We do so by modifying, at the expense of implementation practicality, the signaling complexity of well behaved existing schemes.
The modification allows the same good performance (DMT optimality) in the presence of synchronicity, and almost-surely permits
full-diversity gains for any event of symbol asynchronicity.
This work was in part carried out while Petros Elia was at the University of Southern California. This research is supported
in part by NSF-ITR CCR-0326628. 相似文献
129.
Jorge Bedia Elia Ruiz Juan de Riva Victor R. Ferro Jose Palomar Juan Jose Rodriguez 《American Institute of Chemical Engineers》2013,59(5):1648-1656
Conductor‐like‐screening model for real solvents (COSMO‐RS) method was used to analyze the solute‐solvent interactions and to screen Henry's law constant of toluene over 272 ionic liquids (ILs), to select high‐capacity absorbents. Thermogravimetric experiments were carried out to evaluate the toluene absorption by selected ILs at different temperatures and atmospheric pressure. Experimental equilibrium data were found in good agreement with COSMO‐RS predictions. Complete desorption of toluene by N2 stripping was achieved, indicating an easy regeneration. The kinetic curves were described by a phenomenological diffusion model, obtaining effective diffusivities in reasonable concordance with those calculated by Wilke–Chang correlation. The separation process with selected ILs was modeled by Aspen Plus and a comparison with organic absorbents was carried out. Equilibrium‐ and rate‐based simulations were used to analyze the importance of thermodynamics and kinetics in toluene absorption by ILs. Current computational‐experimental research allowed selecting a set of suitable ILs for toluene absorption. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1648–1656, 2013 相似文献
130.