46 research outputs found

    Drag reduction by polymer additives in decaying turbulence

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    We present results from a systematic numerical study of decaying turbulence in a dilute polymer solution by using a shell-model version of the finitely extensible nonlinear elastic and Peterlin equations. Our study leads to an appealing definition of the drag reduction for the case of decaying turbulence. We exhibit several new results, such as the potential-energy spectrum of the polymer, hitherto unobserved features in the temporal evolution of the kinetic-energy spectrum, and characterize intermittency in such systems. We compare our results with the Gledzer-Ohkitani-Yamada shell model for fluid turbulence

    Hydrogen as a Clean Energy Source

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    Sustainable development of the world is mainly dependent on the use of present energy resources, which primarily includes water, wind, solar, geothermal, and nuclear power. Hydrogen as a clean and green energy source can be the resolution of the energy challenge and may satisfy the demands of several upcoming generations. Hydrogen when used it does not produce any type of pollutant and this makes it a best candidate as a clean energy. Hydrogen energy can be generated from natural gas, oil, biomass, and fossil fuels using thermochemical, photocatalytic, microbiological and electrolysis processes. Large scale hydrogen production is also testified up to some extent with proper engineering for multi applications. Alas, storage and transportation of hydrogen are the main challenge amongst scientific community. Photocatalytic hydrogen production with good efficiencies and amount is well discussed. Till date, using a variety of metal oxide-sulfide, carbon-based materials, metal organic frameworks are utilized by doping or with their composites for enhance the hydrogen production. Main intents of this chapter are to introduce all the possible areas of hydrogen applications and main difficulties of hydrogen transportation, storage and achievements in the hydrogen generation with its applications

    Sentence interpretation in normal and aphasic Hindi speakers.

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    This is a research study comparing the relative informativeness of different linguistic cues for assigning agenthood in Hindi sentence comprehension among brain-intact and aphasic language users.In interpreting a sentence, listeners rely on a variety of linguistic cues to assign grammatical roles such as agent and patient. The present study considered the relative ranking of three cues to agenthood (word order, noun animacy, and subject-verb agreement) in normal and aphasic speakers of Hindi. Because animacy plays a grammatical role in Hindi (determining the nature and acceptability of sentences without accusative marking), this language is relevant to the claim that Broca’s aphasia involves a dissociation between grammar and semantics. Results of Study 1 with normal Hindi-dominant speakers showed that animacy is the strongest cue in this language, while agreement is the weakest cue. In Study 2, Hindi-English bilinguals were tested in both their languages. Most showed the normal animacy-dominant monolingual pattern in Hindi, with a mixture of strategies from both languages in their interpretation of English. A substantial minority showed mixed strategies in both languages. Only 5 of 48 subjects displayed a complete separation between languages, with animacy dominance in Hindi and word order dominance in English. In Study 3, two Hindi-English bilinguals with Broca’s aphasia were tested in both languages. Results indicate (a) greater use of animacy in Hindi than in English and (b) greater use of word order in English than in Hindi. The strategies displayed by these patients fall well within the range observed among bilingual normals. We conclude that the use of animacy in sentence interpretation by these aphasic patients reflects preservation of normal, language-specific processing strategies; it cannot be interpreted as a nonlinguistic strategy developed to compensate for receptive agrammatism. Results are discussed in light of other cross-linguistic evidence on sentence comprehension in monolingual and bilingual aphasics

    Instantaneous Amplitude and Frequency Modulations Detect the Footprint of Rotational Activity and Reveal Stable Driver Regions as Targets for Persistent Atrial Fibrillation Ablation

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    RATIONALE: Costly proprietary panoramic multielectrode (64-256) acquisition systems are being increasingly used together with conventional electroanatomical mapping systems for persistent atrial fibrillation (PersAF) ablation. However, such approaches target alleged drivers (rotational/focal) regardless of their activation frequency dynamics. OBJECTIVES: To test the hypothesis that stable regions of higher than surrounding instantaneous frequency modulation (iFM) drive PersAF and determine whether rotational activity is specific for such regions. METHODS AND RESULTS: First, novel single-signal algorithms based on instantaneous amplitude modulation (iAM) and iFM to detect rotational-footprints without panoramic multielectrode acquisition systems were tested in 125 optical movies from 5 ex vivo Langendorff-perfused PersAF sheep hearts (sensitivity/specificity, 92.6/97.5%; accuracy, 2.5-mm) and in computer simulations. Then, 16 pigs underwent high-rate atrial pacing to develop PersAF. After a median (interquartile range [IQR]) of 4.4 (IQR, 2.5-9.9) months of high-rate atrial pacing followed by 4.1 (IQR, 2.7-5.4) months of self-sustained PersAF, pigs underwent in vivo high-density electroanatomical atrial mapping (4920 [IQR, 4435-5855] 8-second unipolar signals per map). The first 4 out of 16 pigs were used to adapt ex vivo optical proccessing of iFM/iAM to in vivo electrical signals. In the remaining 12 out of 16 pigs, regions of higher than surrounding average iFM were considered leading-drivers. Two leading-driver + rotational-footprint maps were generated 2.6 (IQR, 2.4-2.9) hours apart to test leading-driver spatiotemporal stability and guide ablation. Leading-driver regions (2.5 [IQR, 2.0-4.0] regions/map) exactly colocalized (95.7%) in the 2 maps, and their ablation terminated PersAF in 92.3% of procedures (radiofrequency until termination, 16.9 [IQR, 9.2-35.8] minutes; until nonsustainability, 20.4 [IQR, 12.8-44.0] minutes). Rotational-footprints were found at every leading-driver region, albeit most (76.8% [IQR, 70.5%-83.6%]) were located outside. Finally, the translational ability of this approach was tested in 3 PersAF redo patients. CONCLUSIONS: Both rotational-footprints and spatiotemporally stable leading-driver regions can be located using iFM/iAM algorithms without panoramic multielectrode acquisition systems. In pigs, ablation of leading-driver regions usually terminates PersAF and prevents its sustainability. Rotational activations are sensitive but not specific to such regions. Single-signal iFM/iAM algorithms could be integrated into conventional electroanatomical mapping systems to improve driver detection accuracy and reduce the cost of patient-tailored/mechanistic approaches.This study was supported by the European Regional Development Fund and the Spanish Ministry of Science, Innovation and Universities (SAF2016-80324-R). The CNIC is supported by the Spanish Ministry of Science, Innovation and Universities and the Pro-CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505).S

    Organic Semiconductor for Hydrogen Production

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    The quest of conquering balanced environment for the ultimate search of “Who am I” furnished to pollution and energy crises. As the viable world development is dependent on effective utilization of available renewable energy resources. Hydrogen fuel as an energy source is the future for many upcoming generations as it never produces pollutants. 6, 13 Pentacenequinone (PENQ) is recently developed and reported organic photocatalyst for the generation of hydrogen from water as well as hydrogen sulfide. PENQ can be synthesized and characterized using different methods and techniques/approaches that are listed in this chapter. Green Solid state synthesis method of PENQ is the most promising one as it gives high yield at room temperature and without solvents. Structural characterization of this novel organic catalyst were done using powdered XRD. Cyclic voltammetry is used for the calculating the difference between valance and conduction band levels in the organic PENQ catalyst. After complete structural and morphological characterization, organic PENQ was explored for the hydrogen production from hydrogen sulfide. This photocatalytic nature was also being confirmed using its composites/ coupled systems (PENQ: TiO2 and PENQ: MoS2) using hydrogen sulfide and water

    Six-membered ring systems: with O and/or S atoms

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    A large variety of publications have emerged in 2012 involving O- and S-6- membered ring systems. The increasing number of reviews and other communica- tions dedicated to natural and synthetic derivatives and their biological significance highlights the importance of these heterocycles. Reviews on natural products involve biosynthesis and isolation of enantiomeric derivatives h12AGE4802i, biosynthesis, isolation, synthesis, and biological studies on the pederin family h12NPR980i and xanthones obtained from fungi, lichens, and bacteria h12CR3717i and on the potential chemotherapeutic value of phyto- chemical products and plant extracts as antidiabetic h12NPR580i, antimicrobial, and resistance-modifying agents h12NPR1007i. A more specific review covers a structure–activity relationship of endoperoxides from marine origin and their antitry- panosomal activity h12OBC7197i. New synthetic routes to naturally occurring, biologically active pyran derivatives have been the object of several papers. Different approaches have been discussed for the total synthesis of tetrahydropyran-containing natural products (")-zampanolide h12CEJ16868, 12EJO4130, 12OL3408i, (")-aspergillides A and B h12H(85)587, 12H(85)1255, 12TA252i, (þ)-neopeltolide h12JOC2225, 12JOC9840, 12H(85) 1255i, or their macrolactone core h12OBC3689, 12OL2346i. The total synthesis of bistramide A h12CEJ7452i and (þ)-kalihinol A h12CC901i and the stereoselec- tive synthesis of a fragment of bryostatin h12S3077, 12TL6163i have also been sur- veyed. Other papers relate the total synthesis of naturally occurring carbocyclic and heterocyclic-fused pyran compounds, such as (")-dysiherbaine h12CC6295i, penos- tatin B h12OL244i, Greek tobacco lactonic products, and analogues h12TL4293i and on the structurally intriguing limonoids andhraxylocarpins A–E h12CEJ14342i. The stereocontrolled synthesis of fused tetrahydropyrans was used in the preparation of blepharocalyxin D h12AGE3901i. Polyphenolic heterocyclic compounds have also received great attention in 2012. The biological activities and the chemistry of prenylated caged xanthones h12PCB78i, the occurrence of sesquiterpene coumarins h12PR77i, and the medicinal properties of the xanthone mangiferin h12MRME412i have been reviewed. An overview on the asymmetric syntheses of flavanones and chromanones h12EJO449i, on the synthesis and reactivity of flavones h12T8523i and xanthones h12COC2818i, on the synthesis and biosynthesis of biocoumarins h12T2553i, and on the synthesis and applications of flavylium compounds h12CSR869i has been discussed. The most recent developments in the synthesis and applications of sultones, a very important class of sulfur compounds, were reported h12CR5339i. A review on xanthene-based fluorescent probes for sensing cations, anions, bio- logical species, and enzyme activity has described the spiro-ring-opening approach with a focus on the major mechanisms controlling their luminescence behavior h12CR1910i. The design and synthesis of other derivatives to be used as sensors of gold species h12CC11229i and other specific metal cations h12PC823i have also been described. Recent advances related to coumarin-derived fluorescent chemosen- sors for metal ions h12COC2690i and to monitoring in vitro analysis and cellular imaging of monoamine oxidase activity h12CC6833i have been discussed. The study of various organic chromophores allowed the synthesis of novel dica- tionic phloroglucinol-type bisflavylium pigments h12SL2053i, and the optical and spectroscopic properties of several synthetic 6-aryldibenzo[b,d]pyrylium salts were explored h12TL6433i. Discussion of specific reactions leading to O- and S-membered heterocyclic compounds covers intramolecular radical cyclization h12S2475i and asymmetric enamine and dienamine catalysis h12EJO865i, oxa-Michael h12CSR988i and dom- ino Knoevenagel–hetero-Diels–Alder (hDA) reactions h12T5693i, and the versatility in cycloadditions as well as nucleophilic reactions using o-quinones h12CSR1050i. The use of specific reagents relevant to this chapter includes molecular iodine h12CEJ5460, 12COS561i, samarium diiodide–water for selective reductive transfor- mations h12CC330i, o-quinone methides as versatile intermediates h12CEJ9160i, InCl3 as catalyst h12T8683i, and gold and platinum p-acid mediated insertion of alkynes into carbon–heteroatom s-bonds h12S3401i. The remainder of this chapter discusses the most studied transformations on O- and S-6-membered heterocycles

    withdrawn 2017 hrs ehra ecas aphrs solaece expert consensus statement on catheter and surgical ablation of atrial fibrillation

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    Drag reduction by polymer additives in decaying turbulence

    No full text
    We present results from a systematic numerical study of decaying turbulence in a dilute polymer solution by using a shell-model version of the finitely extensible nonlinear elastic and Peterlin equations.Our study leads to an appealing definition of the drag reduction for the case of decaying turbulence. We exhibit several new results, such as the potential-energy spectrum of the polymer, hitherto unobserved features in the temporal evolution of the kinetic-energy spectrum, and characterize intermittency in such systems. We compare our results with the Gledzer-Ohkitani-Yamada shell model for fluid turbulence

    Articulation Defects in Cleft Palate Cases

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    The present study was conducted on 56 cases of cleft palate and/or lip attending the Rehabilitation Unit in Audiology and Speech Pethology, All India Institute of Medical Sciences, New Delhi. Cleft palate was found to be more prevalent in males than females. 75% of the cases were below the age of 14 years, Only a few parents could give relevant history. It was, therefore, difficult to establish and generalise the causative factors. 29% of the cleft palate cases had mild to moderate degree of hearing loss. About 42% of the cases had undergone palate surgery and 35% both the lip and palate surgery. Many cases reported late for surgical treatment. Velar sounds among all the consonants were found to be substituted most and fricatives were distorted. Distortion was the most common defective articulatory pattern in the cleft palate cases while omissions were least affected. There has been numerous investigations designed to describe the speech articulation on cleft palate. The studies vary in terms of subjects used and the methods of assessment. Yet there is a general agreement on this problem. Plosives, fricatives and consonants which require building up of maximum oral pressure are the most affected sounds in cleft palate speech
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