6,810 research outputs found
Genetic Analysis of ABO and Rh Blood Groups in Brahmin Population of Uttar Pradesh, India”
No full textA series of glycoprotein and glycolipids on the red blood cell surface constitute blood group antigens. These are A, B, AB and O in ABO blood group system and Rh in rhesus blood group system. These antigens are genetically controlled. Certain diseases have been shown to be associated with certain blood groups. In the present study an attempt is made to study the distribution of ABO and Rh. (D) blood group systems among the Brahmin caste population of Uttar Pradesh State. A total of 200 unrelated Brahmin individuals from Uttar Pradesh were studied for the phenotype and allele frequency distribution of ABO and Rh (D) blood groups. The order of occurrence of ABO phenotypes is B>O>A>AB. The corresponding allele frequencies of O, A, and B alleles are found to be 0.5790, 0.1510 and 0.2697 respectively. The allele frequency of D (0.735) is more than d (0.265). The present study was compared with the other studies reported to understand the affinity between them
A rhodium complex with one Rh...C-C and one Rh...H-C agostic bond.
No full text(Figure Presented) Hidden qualities: [Rh(PiPr3) (C 14H16)]-[BArF4] (1; see picture of the cation; P violet, Rh olive green), which was synthesized by treatment of [RhCl(nbd)-(PiPr3)] with Na[BArF4] (BAr F4 = B{C6H3-(CF3) 2}4) and norbornadiene (nbd) in fluorobenzene, contains an organic fragment derived from Binor-S as well as agostic Rh⋯CC and Rh⋯HC interactions. In solution, 1 undergoes rapid, reversible C-C activation/reductive elimination. © 2006 Wiley-VCH Verlag GmbH and Co. KGaA
Single atom dispersed Rh-biphephos&PPh3@porous organic copolymers: highly efficient catalysts for continuous fixed-bed hydroformylation of propene
No full textA vinyl functionalized biphephos ligand with high steric hindrance was copolymerized with tris(4-vinphenyl)phosphane and other ligands to afford efficient porous organic copolymers (POPs) through the solvothermal synthesis technique. By employing the copolymer self-supported heterogeneous Rh/CPOL-bp&P catalysts, the hydroformylation of propene to linear-butaldehyde can be performed efficiently in a continuous fixed-bed reactor with high regioselectivity (l/b > 24), activity (TOF > 1200 h(-1)) and stability (over 1000 h) under mild conditions (70 degrees C, 0.5 MPa), which represents a substantial improvement in the efficiency of this important industrial process. EXAFS and HAADF-STEM showed that the Rh was a single atom dispersion, which explained well the high efficiency of the Rh/CPOL-bp&P catalysts. Compared with liquid-liquid biphasic (LLB) and ionic liquid (IL) systems, this highly efficient solvent free system has the advantages of simple operability, and almost no waste emission, which meets the demands of green industrial processing
Green algae concentration as a function of RH.
No full textMeasured data (blue points = all, blue circles = only data for day without rain) and data calculated using DRF by considering only RH (Eq (1), Table 6, green circles) or RH, rain and T (Eq (3), red crosses) for each situation: A. VA1 and VA2 (Eq (3) becomes Eq (4)); B. VA3 (Eq (5); C. VNA4 and VNA5 (Eq (6); D. VNA6 (Eq (7)).</p
Proportion of green and brown pupae at high and low RH.
No full textProportion of green and brown pupae at high and low RH.</p
Rh-carbossimetilcellulosa (Rh-CMC): un efficiente catalizzatore per idrogenazioni ed idroformilazioni in ambiente bifasico acquoso
No full textDa alcuni anni i nostri studi sono indirizzati alla preparazione ed utilizzo di nuovi sistemi catalitici per effettuare reazioni in ambiente acquoso o bifasico acquoso-organico. Ultimamente abbiamo impiegato l’esopolisaccaride biogenerato EPS, contenente gruppi carbossilici, come legante per diversi metalli e scarti metallici quali Pd, Rh, Pt, ed i sistemi catalitici ottenuti, mono- o poli-metallici, sono stati impiegati con successo in reazioni di idrogenazione,1-2 idroformilazione3 e deidroclorurazione di inquinanti quali Aroclor.4 Considerato il crescente interesse verso l’impiego del sale sodico della carbossimetilcellulosa (CMC) quale legando per ottenere sistemi catalitici a base di metalli quali Cu, Pd, Pt e Ru, e la disponibilità commerciale di CMC, abbiamo pensato di esplorare l’attività di un nuovo catalizzatore idrosolubile a base di rodio, (Rh-CMC). I precursori catalitici sono stati ottenuti in maniera molto semplice, facendo reagire RhCl3 o [Rh(COD)Cl]2 con CMC in acqua a pH alcalino e le soluzioni risultanti sono state quindi impiegate in alcune reazioni modello di idrogenazione e di idroformilazione.
Modulando le condizioni operative dell’idrogenazione del 2-cicloesen-1-one, [T e p(H2)], ed il precursore di Rh, è stato visto che è possibile ottenere preferenzialmente il cicloesanone o il cicloesanolo con buone rese e selettività. Rh-CMC è stato anche impiegato nell’idroformilazione bifasica acquosa dello stirene. Lavorando, ad esempio, con un rapporto molare substrato/catalizzatore = 200/1, a 60°C, e 4 Mpa di syngas (CO/H2 = 1) in H2O/toluene, dopo 18h di reazione si è ottenuta una conversione >99%, una resa in aldeidi > 97% ed un rapporto tra le aldeidi ramificata/lineare pari a ca. 86/14. Quantità assai limitate di prodotti di idrogenazione, quali etilbenzene (1,2%) e 2-fenilpropanolo (0,9%) sono state anche evidenziate. Il catalizzatore è risultato riciclabile. Attualmente sono in corso ulteriori prove per ottimizzare ed estendere le applicazioni di Rh-CMC e studi analitici per ottenere informazioni sulla sua struttura
Self-archiving practice and the influence of publisher policies in the social sciences
No full textAuthors in different disciplines exhibit very different behaviours on the so-called ‘green’ road to open access, i.e. self-archiving. This study looks at the self-archiving behaviour of authors publishing in leading journals in six social science disciplines. It tests the hypothesis that authors are self-archiving according to the norms of their respective disciplines rather than following self-archiving policies of publishers, and that, as a result, they are self-archiving significant numbers of publisher PDF versions. It finds significant levels of
self-archiving, as well as significant self-archiving of
the publisher PDF version, in all the disciplines
investigated. Publishers’ self-archiving policies have
no influence on author self-archiving practice
Development of Core-Shell Rh@Pt and Rh@Ir Nanoparticle Thin Film Using Atomic Layer Deposition for HER Electrocatalysis Applications
No full textThe efficiency of hydrogen gas generation via electrochemical water splitting has been mostly limited by the availability of electrocatalyst materials that require lower overpotentials during the redox reaction. Noble metals have been used extensively as electrocatalysts due to their high activity and low overpotentials. However, the use of single noble metal electrocatalyst is limited due to atomic aggregation caused by its inherent high surface energy, which results in poor structural stability, and, hence, poor electrocatalytic performance and long-term stability. In addition, using noble metals as electrocatalysts also causes the cost to be unnecessarily high. These limitations in noble metal electrocatalysts could be enhanced by combining two noble metals in a core-shell structure (e.g., Rh@Ir) as a thin film over a base substrate. This could significantly enhance electrocatalytic activity due to the following: (1) the modification of the electronic structure, which increases electrical conductivity; (2) the optimization of the adsorption energy; and (3) the introduction of new active sites in the core-shell noble metal structure. The current state-of-the-art employs physical vapor deposition (PVD) or other deposition techniques to fabricate core-shell noble metals on flat 2D substrates. This method does not allow 3D substrates with high surface areas to be used. In the present work, atomic layer deposition (ALD) was used to fabricate nanoparticle thin films of Rh@Ir and Rh@Pt in a core-shell structure on glassy carbon electrodes. ALD enables the fabrication of nanoparticle thin film on three-dimensional substrates (a 2D functional film on a 3D substrate), resulting in a significantly increased surface area for a catalytic reaction to take place; hence, improving the performance of electrocatalysis. The Rh@Pt (with an overpotential of 139 mV and a Tafel slope of 84.8 mV/dec) and Rh@Ir (with an overpotential of 169 mV and a Tafel slope of 112 mV/dec) core-shell electrocatalyst exhibited a better electrocatalytic performances compared to the single metal Rh electrocatalyst (with an overpotential of 300 mV and a Tafel slope of 190 mV/dec). These represented a 54% and a 44% improvement in performance, respectively, illustrating the advantages of core-shell thin film nanostructures in enhancing the catalytic performance of an electrocatalyst. Both electrocatalysts also exhibited good long-term stability in the harsh acidic electrolyte conditions when subjected to chronopotentiometry studies
- …
