8,046 research outputs found
Comparison of the Rate Constants of •OH, SO4•−, CO3•−, Cl2•−, Cl•, ClO• and H• Reactions with Organic Water Contaminants
No full textThe reactions of 7 radicals, which play a key role in the degradation of water contaminants in Advanced Oxidation Processes, were discussed and compared. For evaluation of the reactivities and comparisons, the chemical reactivity rate constants were used, i.e., the rate constant that would be measured if diffusion of the species was not rate-influencing (kchem). By selecting appropriate diffusion-controlled rate constants (kdiff) and using the measured rate constant (k) values, kchem was calculated by the Noyes equation: 1/k = 1/kchem + 1/kdiff. When k and kdiff were close to each other, kchem was much higher than k. log kchem values showed good correlation in the cases of the •OH-H•, SO4•−-•OH, and Cl2•−-CO3•− radical pairs, moderate correlation was found in the case of the CO3•−-ClO• pair. The correlations may reflect, at least partly, similar reaction mechanisms, and allow estimation of unknown rate constant values. No correlation was found for the •OH-Cl• pair; this indicates highly different reaction mechanisms. The reactivity of oxidizing radicals decreases with decreasing reduction potential in the order: Cl• > •OH > SO4•− > Cl2•− > CO3•− > ClO•. The reductive H• reactions with organic molecules are similar to those of •OH, although the H• rate constants are 0.5–1 order of magnitude smaller
Weighing Neutrinos with Cosmic Neutral Hydrogen
No full textWe investigate the signatures left by massive neutrinos on the spatial distribution of neutral hydrogen (H I) in the post-reionization era by running hydrodynamic simulations that include massive neutrinos as additional collisionless particles. We find that halos in massive/massless neutrino cosmologies host a similar amount of neutral hydrogen, although for a fixed halo mass, on average, the H I mass increases with the sum of the neutrino masses. Our results show that H I is more strongly clustered in cosmologies with massive neutrinos, while its abundance, Omega(H I) (z), is lower. These effects arise mainly from the impact of massive neutrinos on cosmology: they suppress both the amplitude of the matter power spectrum on small scales and the abundance of dark matter halos. Modeling the H I distribution with hydrodynamic simulations at z > 3 and a simple analytic model at z < 3, we use the Fisher matrix formalism to conservatively forecast the constraints that Phase 1 of the Square Kilometre Array will place on the sum of neutrino masses, M-nu = Sigma m(nu). We find that with 10,000 hr of interferometric observations at 3 less than or similar to z less than or similar to 6 from a deep and narrow survey with SKA1-LOW, the sum of the neutrino masses can be measured with an error sigma(M-nu) less than or similar to 0.3 eV (95% CL). Similar constraints can be obtained with a wide and deep SKA1-MID survey at z less than or similar to 3, using the single-dish mode. By combining data from MID, LOW, and Planck, plus priors on cosmological parameters from a Stage IV spectroscopic galaxy survey, the sum of the neutrino masses can be determined with an error sigma(M-nu) similar or equal to 0.06 eV (95% CL)
Open access self-archiving: An author study
No full textThis, our second author international, cross-disciplinary study on open access had 1296 respondents. Its focus was on self-archiving. Almost half (49%) of the respondent population have self-archived at least one article during the last three years. Use of institutional repositories for this purpose has doubled and usage has increased by almost 60% for subject-based repositories. Self-archiving activity is greatest amongst those who publish the largest number of papers. There is still a substantial proportion of authors unaware of the possibility of providing open access to their work by self-archiving. Of the authors who have not yet self-archived any articles, 71% remain unaware of the option. With 49% of the author population having self-archived in some way, this means that 36% of the total author population (71% of the remaining 51%), has not yet been appraised of this way of providing open access. Authors have frequently expressed reluctance to self-archive because of the perceived time required and possible technical difficulties in carrying out this activity, yet findings here show that only 20% of authors found some degree of difficulty with the first act of depositing an article in a repository, and that this dropped to 9% for subsequent deposits. Another author worry is about infringing agreed copyright agreements with publishers, yet only 10% of authors currently know of the SHERPA/RoMEO list of publisher permissions policies with respect to self-archiving, where clear guidance as to what a publisher permits is provided. Where it is not known if permission is required, however, authors are not seeking it and are self-archiving without it. Communicating their results to peers remains the primary reason for scholars publishing their work; in other words,
researchers publish to have an impact on their field. The vast majority of authors (81%) would willingly comply with a mandate from their employer or research funder to deposit copies of their articles in an institutional or subject-based repository. A further 13% would comply reluctantly; 5% would not comply with such a mandate
Relationship of DAG1 and SERPINA5 Sperm Proteins With Bull Fertility
No full textStudy Description:
Semen from 22 dairy bulls was used to evaluate the presence, localization, and quantification of DAG1 and SERPINA5 on sperm. Sperm motility parameters and viability was also evaluated for semen from each bull. Semen from 19 out of the 22 dairy bulls was used for in vitro embryo production (two Low-SCR and one High-SCR were not available for in vitro embryo production). Bulls were classified based on their sire conception rates (SCR) values as High-SCR (SCR \u3e 1.0) or Low-SCR fertility (SCR \u3c -4.0). Low fertility bulls were subdivided based on their blastocyst rate (BL) as High-BL (Low-SCR/High-BL BL ≥ 31%) or Low-BL (Low-SCR/Low-BL BL ≤ 26%), and High-SCR bulls were not subdivided. The GLM procedure in SAS was used with bull as a fixed effect to determine if variance was greater between bulls compared to within bull. Correlations were determined among DAG1 and SERPINA5 concentrations, percentage of tail labeled for SERPINA5, SCR, sperm total motility, progressive motility, and viability, and in vitro embryo produced cleavage rate (CL) and BL. The GLIMMIX procedure of SAS was used to evaluate the relationship of bull field fertility (High- and Low-SCR), and field and in vitro fertility (High-SCR, Low-SCR/High-BL, Low-SCR/Low-BL) classifications with sperm total (TMOT) and progressive (PROG) motility, viability, CL, BL, DAG1 and SERPINA5 relative concentration, and proportion of sperm tail labeled for SERPINA5. Both SERPINA5 and DAG1 were localized on the sperm head; however, SERPINA5 was also localized on the sperm tail. There was greater variance in concentration among bulls compared to within bull for both DAG1 (P \u3c 0.01; 69.4 vs 49.1, respectively) and SERPINA5 (P \u3c 0.01; 325.8 vs 285.4, respectively). There was a positive correlation between concentration of DAG1 and SERPINA5 (P = 0.01; r = 0.54). Concentrations of SERPINA5 were also correlated with CL (P = 0.04; r = 0.48), and percentage of sperm tail labeled for SERPINA5 was correlated with viability (P = 0.05; r = 0.44) and tended to be correlated with CL (P = 0.10; r = 0.39). There was no relationship between SCR or BL rate classifications and DAG1 (P ≥ 0.66), SERPINA5 (P ≥ 0.54), or percentage of sperm tail labeled for SERPINA5 (P ≥ 0.48)
Progress of international hydrogen production network for the thermochemical Cu–Cl cycle
No full textThis paper presents recent advances by an international team which is developing the thermochemical copper–chlorine (Cu–Cl) cycle for hydrogen production. Development of the Cu–Cl cycle has been pursued by several countries within the framework of the Generation IV International Forum (GIF) for hydrogen production with the next generation of nuclear reactors. Due to its lower temperature requirements in comparison with other thermochemical cycles, the Cu–Cl cycle is particularly well matched with Canada's Generation IV reactor, SCWR (Super-Critical Water Reactor), as well as other heat sources such as solar energy or industrial waste heat. In this paper, recent developments of the Cu–Cl cycle are presented, specifically involving unit operation experiments, corrosion resistant materials and system integration.Atomic Energy of Canada LimitedOntario Research Excellence FundNatural Sciences and Engineering Research Council of CanadaUniversity Network of Excellence in Nuclear Engineering (UNENE)Canada Research Chairs progra
ŻYCIE UKRYTE W SŁOWIE. "BEKSIŃSCY. PORTRET PODWÓJNY" MAGDALENY GRZEBIAŁKOWSKIEJ W ŚWIETLE POSTSTRUKTURALIZMU
No full textLife Hidden in Words. Magdalena Grzebiałkowska\u27s "Beksińscy. Portret podwójny" and Poststructuralism
The article analyzes Magdalena Grzebiałkowska\u27s biographical "Beksińscy. Portret podwójny" which focuses on the lives of Zdzisław Beksiński and Tomasz Beksiński. The author looks at the construction of the biography and its relationship to poststructuralism, which allows for an appreciation of the literary features of the book. He points to how the specificity of the content, language, a mode of narration in Grzebiałkowska\u27s book make it a full-fledged literary work itself. As such the book departs from a typical biographical scheme. Juxtaposing the book with poststructural ideas leads to the reconsideration of the role of the author in the process of shaping of a biographical narrative
(2-Hydroxyethy1)hydraziniurn(2+) dichloride
No full textThe crystal structure of the title compound, C2H10N2O2+&BULL; 2Cl(-), is built up from one 2-hydroxyethylhydrazinium(2+) cation and two Cl- anions. The molecular structure is stabilized by O-H&BULL;&BULL;&BULL; Cl and N-H&BULL;&BULL;&BULL; Cl hydrogen bonds. The crystal structure is stabilized by one N-H&BULL;&BULL;&BULL; O and three N-H&BULL;&BULL;&BULL; Cl interactions, and the three-dimensional network of hydrogen bonds stabilizes the crystal packing. All five hydrazinium H atoms are involved in hydrogen bonds to Cl- anions. The Cl&BULL;&BULL;&BULL; H contact distances range from 2.122 (15) to 2.809 (14) &ANGS;
Systems, methods and devices for the capture and hydrogenation of carbon dioxide with thermochemical Cu—Cl and Mg—Cl—Na/K—CO2 cycles
No full textSystems, methods, and devices for producing hydrogen and capturing CO2 from emissions combine both H2 production and CO2 capture processes in forms of thermochemical cycles to produce useful products from captured CO2. The thermochemical cycles are copper-chlorine (Cu—Cl) and magnesium-chlorine-sodium/potassium cycles (Mg—Cl—Na/K—CO2). One system comprises a Cu—Cl cycle, a CO2 capture loop, and a hydrogenation cycle. Another system comprises an Mg—Cl—Na/K—CO2 cycle and a hydrogenation cycle. Devices for hydrogen production, CO2 capture, hydrogenation, and process and equipment integration include a two-stage fluidized/packed bed, hybrid two-stage spray-fluidized/packed bed reactor, a two-stage wet-mode absorber, a hybrid two-stage absorber, and a catalyst packed/fluidized bed reactor
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